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Diffstat (limited to 'guides/source')
66 files changed, 11151 insertions, 4669 deletions
diff --git a/guides/source/2_2_release_notes.md b/guides/source/2_2_release_notes.md index be00087f63..ac5833e069 100644 --- a/guides/source/2_2_release_notes.md +++ b/guides/source/2_2_release_notes.md @@ -3,7 +3,7 @@ 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/2-2-stable) 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](https://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. @@ -21,8 +21,8 @@ Rails 2.2 supplies an easy system for internationalization (or i18n, for those o * Lead Contributors: Rails i18 Team * More information : * [Official Rails i18 website](http://rails-i18n.org) - * [Finally. Ruby on Rails gets internationalized](http://www.artweb-design.de/2008/7/18/finally-ruby-on-rails-gets-internationalized) - * [Localizing Rails : Demo application](http://github.com/clemens/i18n_demo_app) + * [Finally. Ruby on Rails gets internationalized](https://web.archive.org/web/20140407075019/http://www.artweb-design.de/2008/7/18/finally-ruby-on-rails-gets-internationalized) + * [Localizing Rails : Demo application](https://github.com/clemens/i18n_demo_app) ### Compatibility with Ruby 1.9 and JRuby @@ -34,7 +34,7 @@ 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](getting_started.html) -* [Rails Database Migrations](migrations.html) +* [Rails Database Migrations](active_record_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) @@ -45,7 +45,6 @@ The internal documentation of Rails, in the form of code comments, has been impr * [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. @@ -59,7 +58,7 @@ rake doc:guides This will put the guides inside `Rails.root/doc/guides` and you may start surfing straight away by opening `Rails.root/doc/guides/index.html` in your favourite browser. * Lead Contributors: [Rails Documentation Team](credits.html) -* Major contributions from [Xavier Noria":http://advogato.org/person/fxn/diary.html and "Hongli Lai](http://izumi.plan99.net/blog/.) +* Major contributions from [Xavier Noria](http://advogato.org/person/fxn/diary.html) and [Hongli Lai](http://izumi.plan99.net/blog/). * More information: * [Rails Guides hackfest](http://hackfest.rubyonrails.org/guide) * [Help improve Rails documentation on Git branch](http://weblog.rubyonrails.org/2008/5/2/help-improve-rails-documentation-on-git-branch) @@ -146,7 +145,7 @@ development: * Lead Contributor: [Nick Sieger](http://blog.nicksieger.com/) * More information: - * [What's New in Edge Rails: Connection Pools](http://ryandaigle.com/articles/2008/9/7/what-s-new-in-edge-rails-connection-pools) + * [What's New in Edge Rails: Connection Pools](http://archives.ryandaigle.com/articles/2008/9/7/what-s-new-in-edge-rails-connection-pools) ### Hashes for Join Table Conditions @@ -166,7 +165,7 @@ Product.all(:joins => :photos, :conditions => { :photos => { :copyright => false ``` * More information: - * [What's New in Edge Rails: Easy Join Table Conditions](http://ryandaigle.com/articles/2008/7/7/what-s-new-in-edge-rails-easy-join-table-conditions) + * [What's New in Edge Rails: Easy Join Table Conditions](http://archives.ryandaigle.com/articles/2008/7/7/what-s-new-in-edge-rails-easy-join-table-conditions) ### New Dynamic Finders @@ -239,7 +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](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) + * [What's New in Edge Rails: Shallow Routes](http://archives.ryandaigle.com/articles/2008/9/7/what-s-new-in-edge-rails-shallow-routes) ### Method Arrays for Member or Collection Routes @@ -287,7 +286,7 @@ Action Mailer Action Mailer now supports mailer layouts. You can make your HTML emails as pretty as your in-browser views by supplying an appropriately-named layout - for example, the `CustomerMailer` class expects to use `layouts/customer_mailer.html.erb`. * More information: - * [What's New in Edge Rails: Mailer Layouts](http://ryandaigle.com/articles/2008/9/7/what-s-new-in-edge-rails-mailer-layouts) + * [What's New in Edge Rails: Mailer Layouts](http://archives.ryandaigle.com/articles/2008/9/7/what-s-new-in-edge-rails-mailer-layouts) Action Mailer now offers built-in support for GMail's SMTP servers, by turning on STARTTLS automatically. This requires Ruby 1.8.7 to be installed. @@ -321,7 +320,7 @@ Other features of memoization include `unmemoize`, `unmemoize_all`, and `memoize * Lead Contributor: [Josh Peek](http://joshpeek.com/) * More information: - * [What's New in Edge Rails: Easy Memoization](http://ryandaigle.com/articles/2008/7/16/what-s-new-in-edge-rails-memoization) + * [What's New in Edge Rails: Easy Memoization](http://archives.ryandaigle.com/articles/2008/7/16/what-s-new-in-edge-rails-memoization) * [Memo-what? A Guide to Memoization](http://www.railway.at/articles/2008/09/20/a-guide-to-memoization) ### each_with_object @@ -389,9 +388,9 @@ To avoid deployment issues and make Rails applications more self-contained, it's You can unpack or install a single gem by specifying `GEM=_gem_name_` on the command line. -* Lead Contributor: [Matt Jones](http://github.com/al2o3cr) +* Lead Contributor: [Matt Jones](https://github.com/al2o3cr) * More information: - * [What's New in Edge Rails: Gem Dependencies](http://ryandaigle.com/articles/2008/4/1/what-s-new-in-edge-rails-gem-dependencies) + * [What's New in Edge Rails: Gem Dependencies](http://archives.ryandaigle.com/articles/2008/4/1/what-s-new-in-edge-rails-gem-dependencies) * [Rails 2.1.2 and 2.2RC1: Update Your RubyGems](http://afreshcup.com/2008/10/25/rails-212-and-22rc1-update-your-rubygems/) * [Detailed discussion on Lighthouse](http://rails.lighthouseapp.com/projects/8994-ruby-on-rails/tickets/1128) @@ -411,7 +410,7 @@ Deprecated A few pieces of older code are deprecated in this release: * `Rails::SecretKeyGenerator` has been replaced by `ActiveSupport::SecureRandom` -* `render_component` is deprecated. There's a [render_components plugin](http://github.com/rails/render_component/tree/master) available if you need this functionality. +* `render_component` is deprecated. There's a [render_components plugin](https://github.com/rails/render_component/tree/master) available if you need this functionality. * Implicit local assignments when rendering partials has been deprecated. ```ruby diff --git a/guides/source/2_3_release_notes.md b/guides/source/2_3_release_notes.md index 0a62f34371..1020f4a8e7 100644 --- a/guides/source/2_3_release_notes.md +++ b/guides/source/2_3_release_notes.md @@ -3,14 +3,14 @@ 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/2-3-stable) 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](https://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.github.io/) 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](https://rack.github.io/) modular web server interface, and renewed support for Rails Engines. ### Rack Integration @@ -54,7 +54,7 @@ Documentation The [Ruby on Rails guides](http://guides.rubyonrails.org/) project has published several additional guides for Rails 2.3. In addition, a [separate site](http://edgeguides.rubyonrails.org/) maintains updated copies of the Guides for Edge Rails. Other documentation efforts include a relaunch of the [Rails wiki](http://newwiki.rubyonrails.org/) and early planning for a Rails Book. -* More Information: [Rails Documentation Projects](http://weblog.rubyonrails.org/2009/1/15/rails-documentation-projects.) +* More Information: [Rails Documentation Projects](http://weblog.rubyonrails.org/2009/1/15/rails-documentation-projects) Ruby 1.9.1 Support ------------------ @@ -125,14 +125,14 @@ Order.scoped_by_customer_id(12).scoped_by_status("open") There's nothing to define to use dynamic scopes: they just work. * Lead Contributor: [Yaroslav Markin](http://evilmartians.com/) -* More Information: [What's New in Edge Rails: Dynamic Scope Methods](http://ryandaigle.com/articles/2008/12/29/what-s-new-in-edge-rails-dynamic-scope-methods.) +* More Information: [What's New in Edge Rails: Dynamic Scope Methods](http://archives.ryandaigle.com/articles/2008/12/29/what-s-new-in-edge-rails-dynamic-scope-methods) ### Default Scopes Rails 2.3 will introduce the notion of _default scopes_ similar to named scopes, but applying to all named scopes or find methods within the model. For example, you can write `default_scope :order => 'name ASC'` and any time you retrieve records from that model they'll come out sorted by name (unless you override the option, of course). * Lead Contributor: Paweł Kondzior -* More Information: [What's New in Edge Rails: Default Scoping](http://ryandaigle.com/articles/2008/11/18/what-s-new-in-edge-rails-default-scoping) +* More Information: [What's New in Edge Rails: Default Scoping](http://archives.ryandaigle.com/articles/2008/11/18/what-s-new-in-edge-rails-default-scoping) ### Batch Processing @@ -158,7 +158,7 @@ Note that you should only use this method for batch processing: for small number * More Information (at that point the convenience method was called just `each`): * [Rails 2.3: Batch Finding](http://afreshcup.com/2009/02/23/rails-23-batch-finding/) - * [What's New in Edge Rails: Batched Find](http://ryandaigle.com/articles/2009/2/23/what-s-new-in-edge-rails-batched-find) + * [What's New in Edge Rails: Batched Find](http://archives.ryandaigle.com/articles/2009/2/23/what-s-new-in-edge-rails-batched-find) ### Multiple Conditions for Callbacks @@ -179,7 +179,7 @@ developers = Developer.find(:all, :group => "salary", :having => "sum(salary) > 10000", :select => "salary") ``` -* Lead Contributor: [Emilio Tagua](http://github.com/miloops) +* Lead Contributor: [Emilio Tagua](https://github.com/miloops) ### Reconnecting MySQL Connections @@ -231,11 +231,11 @@ Rails chooses between file, template, and action depending on whether there is a ### Application Controller Renamed -If you're one of the people who has always been bothered by the special-case naming of `application.rb`, rejoice! It's been reworked to be application_controller.rb in Rails 2.3. In addition, there's a new rake task, `rake rails:update:application_controller` to do this automatically for you - and it will be run as part of the normal `rake rails:update` process. +If you're one of the people who has always been bothered by the special-case naming of `application.rb`, rejoice! It's been reworked to be `application_controller.rb` in Rails 2.3. In addition, there's a new rake task, `rake rails:update:application_controller` to do this automatically for you - and it will be run as part of the normal `rake rails:update` process. * More Information: * [The Death of Application.rb](http://afreshcup.com/2008/11/17/rails-2x-the-death-of-applicationrb/) - * [What's New in Edge Rails: Application.rb Duality is no More](http://ryandaigle.com/articles/2008/11/19/what-s-new-in-edge-rails-application-rb-duality-is-no-more) + * [What's New in Edge Rails: Application.rb Duality is no More](http://archives.ryandaigle.com/articles/2008/11/19/what-s-new-in-edge-rails-application-rb-duality-is-no-more) ### HTTP Digest Authentication Support @@ -261,7 +261,7 @@ end ``` * Lead Contributor: [Gregg Kellogg](http://www.kellogg-assoc.com/) -* More Information: [What's New in Edge Rails: HTTP Digest Authentication](http://ryandaigle.com/articles/2009/1/30/what-s-new-in-edge-rails-http-digest-authentication) +* More Information: [What's New in Edge Rails: HTTP Digest Authentication](http://archives.ryandaigle.com/articles/2009/1/30/what-s-new-in-edge-rails-http-digest-authentication) ### More Efficient Routing @@ -304,7 +304,7 @@ Rails now keeps a per-request local cache of read from the remote cache stores, Rails can now provide localized views, depending on the locale that you have set. For example, suppose you have a `Posts` controller with a `show` action. By default, this will render `app/views/posts/show.html.erb`. But if you set `I18n.locale = :da`, it will render `app/views/posts/show.da.html.erb`. If the localized template isn't present, the undecorated version will be used. Rails also includes `I18n#available_locales` and `I18n::SimpleBackend#available_locales`, which return an array of the translations that are available in the current Rails project. -In addition, you can use the same scheme to localize the rescue files in the `public` directory: `public/500.da.html` or `public/404.en.html` work, for example. +In addition, you can use the same scheme to localize the rescue files in the public directory: `public/500.da.html` or `public/404.en.html` work, for example. ### Partial Scoping for Translations @@ -377,8 +377,8 @@ You can write this view in Rails 2.3: * Lead Contributor: [Eloy Duran](http://superalloy.nl/) * More Information: * [Nested Model Forms](http://weblog.rubyonrails.org/2009/1/26/nested-model-forms) - * [complex-form-examples](http://github.com/alloy/complex-form-examples) - * [What's New in Edge Rails: Nested Object Forms](http://ryandaigle.com/articles/2009/2/1/what-s-new-in-edge-rails-nested-attributes) + * [complex-form-examples](https://github.com/alloy/complex-form-examples) + * [What's New in Edge Rails: Nested Object Forms](http://archives.ryandaigle.com/articles/2009/2/1/what-s-new-in-edge-rails-nested-attributes) ### Smart Rendering of Partials @@ -394,7 +394,7 @@ render @article render @articles ``` -* More Information: [What's New in Edge Rails: render Stops Being High-Maintenance](http://ryandaigle.com/articles/2008/11/20/what-s-new-in-edge-rails-render-stops-being-high-maintenance) +* More Information: [What's New in Edge Rails: render Stops Being High-Maintenance](http://archives.ryandaigle.com/articles/2008/11/20/what-s-new-in-edge-rails-render-stops-being-high-maintenance) ### Prompts for Date Select Helpers @@ -421,7 +421,7 @@ You're likely familiar with Rails' practice of adding timestamps to static asset Asset hosts get more flexible in edge Rails with the ability to declare an asset host as a specific object that responds to a call. This allows you to implement any complex logic you need in your asset hosting. -* More Information: [asset-hosting-with-minimum-ssl](http://github.com/dhh/asset-hosting-with-minimum-ssl/tree/master) +* More Information: [asset-hosting-with-minimum-ssl](https://github.com/dhh/asset-hosting-with-minimum-ssl/tree/master) ### grouped_options_for_select Helper Method @@ -498,7 +498,7 @@ Active Support has a few interesting changes, including the introduction of `Obj A lot of folks have adopted the notion of using try() to attempt operations on objects. It's especially helpful in views where you can avoid nil-checking by writing code like `<%= @person.try(:name) %>`. Well, now it's baked right into Rails. As implemented in Rails, it raises `NoMethodError` on private methods and always returns `nil` if the object is nil. -* More Information: [try()](http://ozmm.org/posts/try.html.) +* More Information: [try()](http://ozmm.org/posts/try.html) ### Object#tap Backport @@ -533,7 +533,7 @@ If you look up the spec on the "json.org" site, you'll discover that all keys in ### Other Active Support Changes * You can use `Enumerable#none?` to check that none of the elements match the supplied block. -* If you're using Active Support [delegates](http://afreshcup.com/2008/10/19/coming-in-rails-22-delegate-prefixes/,) the new `:allow_nil` option lets you return `nil` instead of raising an exception when the target object is nil. +* If you're using Active Support [delegates](http://afreshcup.com/2008/10/19/coming-in-rails-22-delegate-prefixes/) the new `:allow_nil` option lets you return `nil` instead of raising an exception when the target object is nil. * `ActiveSupport::OrderedHash`: now implements `each_key` and `each_value`. * `ActiveSupport::MessageEncryptor` provides a simple way to encrypt information for storage in an untrusted location (like cookies). * Active Support's `from_xml` no longer depends on XmlSimple. Instead, Rails now includes its own XmlMini implementation, with just the functionality that it requires. This lets Rails dispense with the bundled copy of XmlSimple that it's been carting around. @@ -555,11 +555,11 @@ Rails Metal is a new mechanism that provides superfast endpoints inside of your * [Introducing Rails Metal](http://weblog.rubyonrails.org/2008/12/17/introducing-rails-metal) * [Rails Metal: a micro-framework with the power of Rails](http://soylentfoo.jnewland.com/articles/2008/12/16/rails-metal-a-micro-framework-with-the-power-of-rails-m) * [Metal: Super-fast Endpoints within your Rails Apps](http://www.railsinside.com/deployment/180-metal-super-fast-endpoints-within-your-rails-apps.html) - * [What's New in Edge Rails: Rails Metal](http://ryandaigle.com/articles/2008/12/18/what-s-new-in-edge-rails-rails-metal) + * [What's New in Edge Rails: Rails Metal](http://archives.ryandaigle.com/articles/2008/12/18/what-s-new-in-edge-rails-rails-metal) ### Application Templates -Rails 2.3 incorporates Jeremy McAnally's [rg](http://github.com/jeremymcanally/rg/tree/master) application generator. What this means is that we now have template-based application generation built right into Rails; if you have a set of plugins you include in every application (among many other use cases), you can just set up a template once and use it over and over again when you run the `rails` command. There's also a rake task to apply a template to an existing application: +Rails 2.3 incorporates Jeremy McAnally's [rg](https://github.com/jm/rg) application generator. What this means is that we now have template-based application generation built right into Rails; if you have a set of plugins you include in every application (among many other use cases), you can just set up a template once and use it over and over again when you run the `rails` command. There's also a rake task to apply a template to an existing application: ``` rake rails:template LOCATION=~/template.rb @@ -572,7 +572,7 @@ This will layer the changes from the template on top of whatever code the projec ### Quieter Backtraces -Building on Thoughtbot's [Quiet Backtrace](https://github.com/thoughtbot/quietbacktrace) plugin, which allows you to selectively remove lines from `Test::Unit` backtraces, Rails 2.3 implements `ActiveSupport::BacktraceCleaner` and `Rails::BacktraceCleaner` in core. This supports both filters (to perform regex-based substitutions on backtrace lines) and silencers (to remove backtrace lines entirely). Rails automatically adds silencers to get rid of the most common noise in a new application, and builds a `config/backtrace_silencers.rb` file to hold your own additions. This feature also enables prettier printing from any gem in the backtrace. +Building on thoughtbot's [Quiet Backtrace](https://github.com/thoughtbot/quietbacktrace) plugin, which allows you to selectively remove lines from `Test::Unit` backtraces, Rails 2.3 implements `ActiveSupport::BacktraceCleaner` and `Rails::BacktraceCleaner` in core. This supports both filters (to perform regex-based substitutions on backtrace lines) and silencers (to remove backtrace lines entirely). Rails automatically adds silencers to get rid of the most common noise in a new application, and builds a `config/backtrace_silencers.rb` file to hold your own additions. This feature also enables prettier printing from any gem in the backtrace. ### Faster Boot Time in Development Mode with Lazy Loading/Autoload @@ -605,8 +605,8 @@ 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). +* 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](https://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](https://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. * `ActionController::Base#session_enabled?` is deprecated because sessions are lazy-loaded now. @@ -614,7 +614,7 @@ A few pieces of older code are deprecated in this release: * 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. * `formatted_polymorphic_url` is deprecated. Use `polymorphic_url` with `:format` instead. * The `:http_only` option in `ActionController::Response#set_cookie` has been renamed to `:httponly`. -* The `:connector` and `:skip_last_comma` options of `to_sentence` have been replaced by `:words_connnector`, `:two_words_connector`, and `:last_word_connector` options. +* The `:connector` and `:skip_last_comma` options of `to_sentence` have been replaced by `:words_connector`, `:two_words_connector`, and `:last_word_connector` options. * Posting a multipart form with an empty `file_field` control used to submit an empty string to the controller. Now it submits a nil, due to differences between Rack's multipart parser and the old Rails one. Credits diff --git a/guides/source/3_0_release_notes.md b/guides/source/3_0_release_notes.md index 9ad32e8168..f0e2cb3b63 100644 --- a/guides/source/3_0_release_notes.md +++ b/guides/source/3_0_release_notes.md @@ -17,7 +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/3-0-stable) 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](https://github.com/rails/rails/commits/3-0-stable) in the main Rails repository on GitHub. -------------------------------------------------------------------------------- @@ -63,7 +63,7 @@ The `config.gem` method is gone and has been replaced by using `bundler` and a ` ### Upgrade Process -To help with the upgrade process, a plugin named [Rails Upgrade](http://github.com/rails/rails_upgrade) has been created to automate part of it. +To help with the upgrade process, a plugin named [Rails Upgrade](https://github.com/rails/rails_upgrade) has been created to automate part of it. Simply install the plugin, then run `rake rails:upgrade:check` to check your app for pieces that need to be updated (with links to information on how to update them). It also offers a task to generate a `Gemfile` based on your current `config.gem` calls and a task to generate a new routes file from your current one. To get the plugin, simply run the following: @@ -86,9 +86,9 @@ $ cd myapp ### Vendoring Gems -Rails now uses a `Gemfile` in the application root to determine the gems you require for your application to start. This `Gemfile` is processed by the [Bundler](http://github.com/carlhuda/bundler,) which then installs all your dependencies. It can even install all the dependencies locally to your application so that it doesn't depend on the system gems. +Rails now uses a `Gemfile` in the application root to determine the gems you require for your application to start. This `Gemfile` is processed by the [Bundler](https://github.com/bundler/bundler) which then installs all your dependencies. It can even install all the dependencies locally to your application so that it doesn't depend on the system gems. -More information: - [bundler homepage](http://gembundler.com) +More information: - [bundler homepage](https://bundler.io/) ### Living on the Edge @@ -138,14 +138,14 @@ More Information: - [Rails Edge Architecture](http://yehudakatz.com/2009/06/11/r ### Arel Integration -[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. +[Arel](https://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](https://web.archive.org/web/20120718093140/http://magicscalingsprinkles.wordpress.com/2010/01/28/why-i-wrote-arel/) ### Mail Extraction -Action Mailer ever since its beginnings has had monkey patches, pre parsers and even delivery and receiver agents, all in addition to having TMail vendored in the source tree. Version 3 changes that with all email message related functionality abstracted out to the [Mail](http://github.com/mikel/mail) gem. This again reduces code duplication and helps create definable boundaries between Action Mailer and the email parser. +Action Mailer ever since its beginnings has had monkey patches, pre parsers and even delivery and receiver agents, all in addition to having TMail vendored in the source tree. Version 3 changes that with all email message related functionality abstracted out to the [Mail](https://github.com/mikel/mail) gem. This again reduces code duplication and helps create definable boundaries between Action Mailer and the email parser. More information: - [New Action Mailer API in Rails 3](http://lindsaar.net/2010/1/26/new-actionmailer-api-in-rails-3) @@ -155,13 +155,13 @@ Documentation The documentation in the Rails tree is being updated with all the API changes, additionally, the [Rails Edge Guides](http://edgeguides.rubyonrails.org/) are being updated one by one to reflect the changes in Rails 3.0. The guides at [guides.rubyonrails.org](http://guides.rubyonrails.org/) however will continue to contain only the stable version of Rails (at this point, version 2.3.5, until 3.0 is released). -More Information: - [Rails Documentation Projects](http://weblog.rubyonrails.org/2009/1/15/rails-documentation-projects.) +More Information: - [Rails Documentation Projects](http://weblog.rubyonrails.org/2009/1/15/rails-documentation-projects) Internationalization -------------------- -A large amount of work has been done with I18n support in Rails 3, including the latest [I18n](http://github.com/svenfuchs/i18n) gem supplying many speed improvements. +A large amount of work has been done with I18n support in Rails 3, including the latest [I18n](https://github.com/svenfuchs/i18n) gem supplying many speed improvements. * I18n for any object - I18n behavior can be added to any object by including `ActiveModel::Translation` and `ActiveModel::Validations`. There is also an `errors.messages` fallback for translations. * Attributes can have default translations. @@ -213,7 +213,6 @@ Railties now deprecates: More information: * [Discovering Rails 3 generators](http://blog.plataformatec.com.br/2010/01/discovering-rails-3-generators) -* [Making Generators for Rails 3 with Thor](http://caffeinedd.com/guides/331-making-generators-for-rails-3-with-thor) * [The Rails Module (in Rails 3)](http://litanyagainstfear.com/blog/2010/02/03/the-rails-module/) Action Pack @@ -250,7 +249,7 @@ Deprecations: More Information: -* [Render Options in Rails 3](http://www.engineyard.com/blog/2010/render-options-in-rails-3/) +* [Render Options in Rails 3](https://blog.engineyard.com/2010/render-options-in-rails-3) * [Three reasons to love ActionController::Responder](http://weblog.rubyonrails.org/2009/8/31/three-reasons-love-responder) @@ -310,7 +309,7 @@ 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](https://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 @@ -576,7 +575,7 @@ 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](https://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`. diff --git a/guides/source/3_1_release_notes.md b/guides/source/3_1_release_notes.md index 537aa5a371..17d4ac23b6 100644 --- a/guides/source/3_1_release_notes.md +++ b/guides/source/3_1_release_notes.md @@ -99,7 +99,7 @@ gem 'jquery-rails' # config.assets.manifest = YOUR_PATH # Precompile additional assets (application.js, application.css, and all non-JS/CSS are already added) - # config.assets.precompile `= %w( search.js ) + # config.assets.precompile `= %w( admin.js admin.css ) # Force all access to the app over SSL, use Strict-Transport-Security, and use secure cookies. @@ -151,7 +151,7 @@ $ cd myapp Rails now uses a `Gemfile` in the application root to determine the gems you require for your application to start. This `Gemfile` is processed by the [Bundler](https://github.com/carlhuda/bundler) gem, which then installs all your dependencies. It can even install all the dependencies locally to your application so that it doesn't depend on the system gems. -More information: - [bundler homepage](http://gembundler.com) +More information: - [bundler homepage](https://bundler.io/) ### Living on the Edge @@ -199,7 +199,7 @@ Railties * jQuery is the new default JavaScript library. -* jQuery and Prototype are no longer vendored and is provided from now on by the jquery-rails and prototype-rails gems. +* jQuery and Prototype are no longer vendored and is provided from now on by the `jquery-rails` and `prototype-rails` gems. * The application generator accepts an option `-j` which can be an arbitrary string. If passed "foo", the gem "foo-rails" is added to the `Gemfile`, and the application JavaScript manifest requires "foo" and "foo_ujs". Currently only "prototype-rails" and "jquery-rails" exist and provide those files via the asset pipeline. @@ -558,4 +558,4 @@ 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 3.1 Release Notes were compiled by [Vijay Dev](https://github.com/vijaydev.) +Rails 3.1 Release Notes were compiled by [Vijay Dev](https://github.com/vijaydev) diff --git a/guides/source/3_2_release_notes.md b/guides/source/3_2_release_notes.md index 6ddf77d9c0..ae6eb27f35 100644 --- a/guides/source/3_2_release_notes.md +++ b/guides/source/3_2_release_notes.md @@ -30,13 +30,13 @@ TIP: Note that Ruby 1.8.7 p248 and p249 have marshalling bugs that crash Rails. ### What to update in your apps -* Update your Gemfile to depend on +* Update your `Gemfile` to depend on * `rails = 3.2.0` * `sass-rails ~> 3.2.3` * `coffee-rails ~> 3.2.1` * `uglifier >= 1.0.3` -* Rails 3.2 deprecates `vendor/plugins` and Rails 4.0 will remove them completely. You can start replacing these plugins by extracting them as gems and adding them in 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`. +* Rails 3.2 deprecates `vendor/plugins` and Rails 4.0 will remove them completely. You can start replacing these plugins by extracting them as gems and adding them in 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`. * There are a couple of new configuration changes you'd want to add in `config/environments/development.rb`: @@ -81,7 +81,7 @@ $ cd myapp Rails now uses a `Gemfile` in the application root to determine the gems you require for your application to start. This `Gemfile` is processed by the [Bundler](https://github.com/carlhuda/bundler) gem, which then installs all your dependencies. It can even install all the dependencies locally to your application so that it doesn't depend on the system gems. -More information: [Bundler homepage](http://gembundler.com) +More information: [Bundler homepage](https://bundler.io/) ### Living on the Edge @@ -154,9 +154,9 @@ Railties rails g scaffold Post title:string:index author:uniq price:decimal{7,2} ``` - will create indexes for `title` and `author` with the latter being an unique index. Some types such as decimal accept custom options. In the example, `price` will be a decimal column with precision and scale set to 7 and 2 respectively. + will create indexes for `title` and `author` with the latter being a unique index. Some types such as decimal accept custom options. In the example, `price` will be a decimal column with precision and scale set to 7 and 2 respectively. -* Turn gem has been removed from default Gemfile. +* Turn gem has been removed from default `Gemfile`. * Remove old plugin generator `rails generate plugin` in favor of `rails plugin new` command. @@ -295,7 +295,7 @@ Action Pack ```ruby @items.each do |item| content_tag_for(:li, item) do - Title: <%= item.title %> + Title: <%= item.title %> end end ``` @@ -327,7 +327,7 @@ Active Record * Implemented `ActiveRecord::Relation#explain`. -* Implements `AR::Base.silence_auto_explain` which allows the user to selectively disable automatic EXPLAINs within a block. +* Implements `ActiveRecord::Base.silence_auto_explain` which allows the user to selectively disable automatic EXPLAINs within a block. * Implements automatic EXPLAIN logging for slow queries. A new configuration parameter `config.active_record.auto_explain_threshold_in_seconds` determines what's to be considered a slow query. Setting that to nil disables this feature. Defaults are 0.5 in development mode, and nil in test and production modes. Rails 3.2 supports this feature in SQLite, MySQL (mysql2 adapter), and PostgreSQL. diff --git a/guides/source/4_0_release_notes.md b/guides/source/4_0_release_notes.md index 9feaff098a..0921cd1979 100644 --- a/guides/source/4_0_release_notes.md +++ b/guides/source/4_0_release_notes.md @@ -36,7 +36,7 @@ $ cd myapp Rails now uses a `Gemfile` in the application root to determine the gems you require for your application to start. This `Gemfile` is processed by the [Bundler](https://github.com/carlhuda/bundler) gem, which then installs all your dependencies. It can even install all the dependencies locally to your application so that it doesn't depend on the system gems. -More information: [Bundler homepage](http://gembundler.com) +More information: [Bundler homepage](https://bundler.io) ### Living on the Edge @@ -60,13 +60,13 @@ Major Features ### 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. +* **[New deprecation policy](https://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. +* **vendor/plugins removed** ([commit](https://github.com/rails/rails/commit/853de2bd9ac572735fa6cf59fcf827e485a231c3)) - Use a `Gemfile` to manage installed gems. ### ActionPack @@ -108,7 +108,7 @@ In Rails 4.0, several features have been extracted into gems. You can simply add * 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)) +* Active Resource ([GitHub](https://github.com/rails/activeresource), [Pull Request](https://github.com/rails/rails/pull/572), [Blog](http://yetimedia-blog-blog.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)) diff --git a/guides/source/4_1_release_notes.md b/guides/source/4_1_release_notes.md index 6bf65757ec..2c5e665e33 100644 --- a/guides/source/4_1_release_notes.md +++ b/guides/source/4_1_release_notes.md @@ -274,7 +274,7 @@ for detailed 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 + 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 diff --git a/guides/source/4_2_release_notes.md b/guides/source/4_2_release_notes.md index 684bd286bc..7105df5634 100644 --- a/guides/source/4_2_release_notes.md +++ b/guides/source/4_2_release_notes.md @@ -179,7 +179,7 @@ change your code to use the explicit form (`render file: "foo/bar"`) instead. `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: +`gem 'responders', '~> 2.0'` to your `Gemfile` to use it: ```ruby # app/controllers/users_controller.rb @@ -227,6 +227,17 @@ 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. +### Changed status option symbols for `render` + +Due to a [change in Rack](https://github.com/rack/rack/commit/be28c6a2ac152fe4adfbef71f3db9f4200df89e8), the symbols that the `render` method accepts for the `:status` option have changed: + +- 306: `:reserved` has been removed. +- 413: `:request_entity_too_large` has been renamed to `:payload_too_large`. +- 414: `:request_uri_too_long` has been renamed to `:uri_too_long`. +- 416: `:requested_range_not_satisfiable` has been renamed to `:range_not_satisfiable`. + +Keep in mind that if calling `render` with an unknown symbol, the response status will default to 500. + ### HTML Sanitizer The HTML sanitizer has been replaced with a new, more robust, implementation @@ -357,7 +368,7 @@ Please refer to the [Changelog][railties] for detailed changes. ### Notable changes -* Introduced `web-console` in the default application Gemfile. +* 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. @@ -394,7 +405,7 @@ Please refer to the [Changelog][railties] for detailed changes. url: http://localhost:3001 namespace: my_app_development - # config/production.rb + # config/environments/production.rb Rails.application.configure do config.middleware.use ExceptionNotifier, config_for(:exception_notification) end @@ -860,7 +871,7 @@ Please refer to the [Changelog][active-support] for detailed changes. `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. +* New [guide](autoloading_and_reloading_constants.html) about constant autoloading and reloading. Credits ------- diff --git a/guides/source/5_0_release_notes.md b/guides/source/5_0_release_notes.md new file mode 100644 index 0000000000..656838c6b8 --- /dev/null +++ b/guides/source/5_0_release_notes.md @@ -0,0 +1,1096 @@ +**DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON http://guides.rubyonrails.org.** + +Ruby on Rails 5.0 Release Notes +=============================== + +Highlights in Rails 5.0: + +* Action Cable +* Rails API +* Active Record Attributes API +* Test Runner +* Exclusive use of `rails` CLI over Rake +* Sprockets 3 +* Turbolinks 5 +* Ruby 2.2.2+ required + +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/5-0-stable) in the main Rails +repository on GitHub. + +-------------------------------------------------------------------------------- + +Upgrading to Rails 5.0 +---------------------- + +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 4.2 in case you +haven't and make sure your application still runs as expected before attempting +an update to Rails 5.0. 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-4-2-to-rails-5-0) +guide. + + +Major Features +-------------- + +### Action Cable + +Action Cable is a new framework in Rails 5. It seamlessly integrates +[WebSockets](https://en.wikipedia.org/wiki/WebSocket) with the rest of your +Rails application. + +Action Cable allows for real-time features to be written in Ruby in the +same style and form as the rest of your Rails application, while still being +performant and scalable. It's a full-stack offering that provides both a +client-side JavaScript framework and a server-side Ruby framework. You have +access to your full domain model written with Active Record or your ORM of +choice. + +See the [Action Cable Overview](action_cable_overview.html) guide for more +information. + +### API Applications + +Rails can now be used to create slimmed down API only applications. +This is useful for creating and serving APIs similar to [Twitter](https://dev.twitter.com) or [GitHub](https://developer.github.com) API, +that can be used to serve public facing, as well as, for custom applications. + +You can generate a new api Rails app using: + +```bash +$ rails new my_api --api +``` + +This will do three main things: + +- Configure your application to start with a more limited set of middleware + than normal. Specifically, it will not include any middleware primarily useful + for browser applications (like cookies support) by default. +- Make `ApplicationController` inherit from `ActionController::API` instead of + `ActionController::Base`. As with middleware, this will leave out any Action + Controller modules that provide functionalities primarily used by browser + applications. +- Configure the generators to skip generating views, helpers and assets when + you generate a new resource. + +The application provides a base for APIs, +that can then be [configured to pull in functionality](api_app.html) as suitable for the application's needs. + +See the [Using Rails for API-only Applications](api_app.html) guide for more +information. + +### Active Record attributes API + +Defines an attribute with a type on a model. It will override the type of existing attributes if needed. +This allows control over how values are converted to and from SQL when assigned to a model. +It also changes the behavior of values passed to `ActiveRecord::Base.where`, which lets use our domain objects across much of Active Record, +without having to rely on implementation details or monkey patching. + +Some things that you can achieve with this: + +- The type detected by Active Record can be overridden. +- A default can also be provided. +- Attributes do not need to be backed by a database column. + +```ruby + +# db/schema.rb +create_table :store_listings, force: true do |t| + t.decimal :price_in_cents + t.string :my_string, default: "original default" +end + +# app/models/store_listing.rb +class StoreListing < ActiveRecord::Base +end + +store_listing = StoreListing.new(price_in_cents: '10.1') + +# before +store_listing.price_in_cents # => BigDecimal.new(10.1) +StoreListing.new.my_string # => "original default" + +class StoreListing < ActiveRecord::Base + attribute :price_in_cents, :integer # custom type + attribute :my_string, :string, default: "new default" # default value + attribute :my_default_proc, :datetime, default: -> { Time.now } # default value + attribute :field_without_db_column, :integer, array: true +end + +# after +store_listing.price_in_cents # => 10 +StoreListing.new.my_string # => "new default" +StoreListing.new.my_default_proc # => 2015-05-30 11:04:48 -0600 +model = StoreListing.new(field_without_db_column: ["1", "2", "3"]) +model.attributes # => {field_without_db_column: [1, 2, 3]} +``` + +**Creating Custom Types:** + +You can define your own custom types, as long as they respond +to the methods defined on the value type. The method `deserialize` or +`cast` will be called on your type object, with raw input from the +database or from your controllers. This is useful, for example, when doing custom conversion, +like Money data. + +**Querying:** + +When `ActiveRecord::Base.where` is called, it will +use the type defined by the model class to convert the value to SQL, +calling `serialize` on your type object. + +This gives the objects ability to specify, how to convert values when performing SQL queries. + +**Dirty Tracking:** + +The type of an attribute is given the opportunity to change how dirty +tracking is performed. + +See its +[documentation](http://api.rubyonrails.org/v5.0.1/classes/ActiveRecord/Attributes/ClassMethods.html) +for a detailed write up. + + +### Test Runner + +A new test runner has been introduced to enhance the capabilities of running tests from Rails. +To use this test runner simply type `bin/rails test`. + +Test Runner is inspired from `RSpec`, `minitest-reporters`, `maxitest` and others. +It includes some of these notable advancements: + +- Run a single test using line number of test. +- Run multiple tests pinpointing to line number of tests. +- Improved failure messages, which also add ease of re-running failed tests. +- Fail fast using `-f` option, to stop tests immediately on occurrence of failure, +instead of waiting for the suite to complete. +- Defer test output until the end of a full test run using the `-d` option. +- Complete exception backtrace output using `-b` option. +- Integration with `Minitest` to allow options like `-s` for test seed data, +`-n` for running specific test by name, `-v` for better verbose output and so forth. +- Colored test output. + +Railties +-------- + +Please refer to the [Changelog][railties] for detailed changes. + +### Removals + +* Removed debugger support, use byebug instead. `debugger` is not supported by + Ruby + 2.2. ([commit](https://github.com/rails/rails/commit/93559da4826546d07014f8cfa399b64b4a143127)) + +* Removed deprecated `test:all` and `test:all:db` tasks. + ([commit](https://github.com/rails/rails/commit/f663132eef0e5d96bf2a58cec9f7c856db20be7c)) + +* Removed deprecated `Rails::Rack::LogTailer`. + ([commit](https://github.com/rails/rails/commit/c564dcb75c191ab3d21cc6f920998b0d6fbca623)) + +* Removed deprecated `RAILS_CACHE` constant. + ([commit](https://github.com/rails/rails/commit/b7f856ce488ef8f6bf4c12bb549f462cb7671c08)) + +* Removed deprecated `serve_static_assets` configuration. + ([commit](https://github.com/rails/rails/commit/463b5d7581ee16bfaddf34ca349b7d1b5878097c)) + +* Removed the documentation tasks `doc:app`, `doc:rails`, and `doc:guides`. + ([commit](https://github.com/rails/rails/commit/cd7cc5254b090ccbb84dcee4408a5acede25ef2a)) + +* Removed `Rack::ContentLength` middleware from the default + stack. ([Commit](https://github.com/rails/rails/commit/56903585a099ab67a7acfaaef0a02db8fe80c450)) + +### Deprecations + +* Deprecated `config.static_cache_control` in favor of + `config.public_file_server.headers`. + ([Pull Request](https://github.com/rails/rails/pull/19135)) + +* Deprecated `config.serve_static_files` in favor of `config.public_file_server.enabled`. + ([Pull Request](https://github.com/rails/rails/pull/22173)) + +* Deprecated the tasks in the `rails` task namespace in favor of the `app` namespace. + (e.g. `rails:update` and `rails:template` tasks are renamed to `app:update` and `app:template`.) + ([Pull Request](https://github.com/rails/rails/pull/23439)) + +### Notable changes + +* Added Rails test runner `bin/rails test`. + ([Pull Request](https://github.com/rails/rails/pull/19216)) + +* Newly generated applications and plugins get a `README.md` in Markdown. + ([commit](https://github.com/rails/rails/commit/89a12c931b1f00b90e74afffcdc2fc21f14ca663), + [Pull Request](https://github.com/rails/rails/pull/22068)) + +* Added `bin/rails restart` task to restart your Rails app by touching `tmp/restart.txt`. + ([Pull Request](https://github.com/rails/rails/pull/18965)) + +* Added `bin/rails initializers` task to print out all defined initializers in + the order they are invoked by Rails. + ([Pull Request](https://github.com/rails/rails/pull/19323)) + +* Added `bin/rails dev:cache` to enable or disable caching in development mode. + ([Pull Request](https://github.com/rails/rails/pull/20961)) + +* Added `bin/update` script to update the development environment automatically. + ([Pull Request](https://github.com/rails/rails/pull/20972)) + +* Proxy Rake tasks through `bin/rails`. + ([Pull Request](https://github.com/rails/rails/pull/22457), + [Pull Request](https://github.com/rails/rails/pull/22288)) + +* New applications are generated with the evented file system monitor enabled + on Linux and macOS. The feature can be opted out by passing + `--skip-listen` to the generator. + ([commit](https://github.com/rails/rails/commit/de6ad5665d2679944a9ee9407826ba88395a1003), + [commit](https://github.com/rails/rails/commit/94dbc48887bf39c241ee2ce1741ee680d773f202)) + +* Generate applications with an option to log to STDOUT in production + using the environment variable `RAILS_LOG_TO_STDOUT`. + ([Pull Request](https://github.com/rails/rails/pull/23734)) + +* Enable HSTS with IncludeSudomains header for new applications. + ([Pull Request](https://github.com/rails/rails/pull/23852)) + +* The application generator writes a new file `config/spring.rb`, which tells + Spring to watch additional common files. + ([commit](https://github.com/rails/rails/commit/b04d07337fd7bc17e88500e9d6bcd361885a45f8)) + +* Added `--skip-action-mailer` to skip Action Mailer while generating new app. + ([Pull Request](https://github.com/rails/rails/pull/18288)) + +* Removed `tmp/sessions` directory and the clear rake task associated with it. + ([Pull Request](https://github.com/rails/rails/pull/18314)) + +* Changed `_form.html.erb` generated by scaffold generator to use local variables. + ([Pull Request](https://github.com/rails/rails/pull/13434)) + +* Disabled autoloading of classes in production environment. + ([commit](https://github.com/rails/rails/commit/a71350cae0082193ad8c66d65ab62e8bb0b7853b)) + +Action Pack +----------- + +Please refer to the [Changelog][action-pack] for detailed changes. + +### Removals + +* Removed `ActionDispatch::Request::Utils.deep_munge`. + ([commit](https://github.com/rails/rails/commit/52cf1a71b393486435fab4386a8663b146608996)) + +* Removed `ActionController::HideActions`. + ([Pull Request](https://github.com/rails/rails/pull/18371)) + +* Removed `respond_to` and `respond_with` placeholder methods, this functionality + has been extracted to the + [responders](https://github.com/plataformatec/responders) gem. + ([commit](https://github.com/rails/rails/commit/afd5e9a7ff0072e482b0b0e8e238d21b070b6280)) + +* Removed deprecated assertion files. + ([commit](https://github.com/rails/rails/commit/92e27d30d8112962ee068f7b14aa7b10daf0c976)) + +* Removed deprecated usage of string keys in URL helpers. + ([commit](https://github.com/rails/rails/commit/34e380764edede47f7ebe0c7671d6f9c9dc7e809)) + +* Removed deprecated `only_path` option on `*_path` helpers. + ([commit](https://github.com/rails/rails/commit/e4e1fd7ade47771067177254cb133564a3422b8a)) + +* Removed deprecated `NamedRouteCollection#helpers`. + ([commit](https://github.com/rails/rails/commit/2cc91c37bc2e32b7a04b2d782fb8f4a69a14503f)) + +* Removed deprecated support to define routes with `:to` option that doesn't contain `#`. + ([commit](https://github.com/rails/rails/commit/1f3b0a8609c00278b9a10076040ac9c90a9cc4a6)) + +* Removed deprecated `ActionDispatch::Response#to_ary`. + ([commit](https://github.com/rails/rails/commit/4b19d5b7bcdf4f11bd1e2e9ed2149a958e338c01)) + +* Removed deprecated `ActionDispatch::Request#deep_munge`. + ([commit](https://github.com/rails/rails/commit/7676659633057dacd97b8da66e0d9119809b343e)) + +* Removed deprecated + `ActionDispatch::Http::Parameters#symbolized_path_parameters`. + ([commit](https://github.com/rails/rails/commit/7fe7973cd8bd119b724d72c5f617cf94c18edf9e)) + +* Removed deprecated option `use_route` in controller tests. + ([commit](https://github.com/rails/rails/commit/e4cfd353a47369dd32198b0e67b8cbb2f9a1c548)) + +* Removed `assigns` and `assert_template`. Both methods have been extracted + into the + [rails-controller-testing](https://github.com/rails/rails-controller-testing) + gem. + ([Pull Request](https://github.com/rails/rails/pull/20138)) + +### Deprecations + +* Deprecated all `*_filter` callbacks in favor of `*_action` callbacks. + ([Pull Request](https://github.com/rails/rails/pull/18410)) + +* Deprecated `*_via_redirect` integration test methods. Use `follow_redirect!` + manually after the request call for the same behavior. + ([Pull Request](https://github.com/rails/rails/pull/18693)) + +* Deprecated `AbstractController#skip_action_callback` in favor of individual + skip_callback methods. + ([Pull Request](https://github.com/rails/rails/pull/19060)) + +* Deprecated `:nothing` option for `render` method. + ([Pull Request](https://github.com/rails/rails/pull/20336)) + +* Deprecated passing first parameter as `Hash` and default status code for + `head` method. + ([Pull Request](https://github.com/rails/rails/pull/20407)) + +* Deprecated using strings or symbols for middleware class names. Use class + names instead. + ([commit](https://github.com/rails/rails/commit/83b767ce)) + +* Deprecated accessing mime types via constants (eg. `Mime::HTML`). Use the + subscript operator with a symbol instead (eg. `Mime[:html]`). + ([Pull Request](https://github.com/rails/rails/pull/21869)) + +* Deprecated `redirect_to :back` in favor of `redirect_back`, which accepts a + required `fallback_location` argument, thus eliminating the possibility of a + `RedirectBackError`. + ([Pull Request](https://github.com/rails/rails/pull/22506)) + +* `ActionDispatch::IntegrationTest` and `ActionController::TestCase` deprecate positional arguments in favor of + keyword arguments. ([Pull Request](https://github.com/rails/rails/pull/18323)) + +* Deprecated `:controller` and `:action` path parameters. + ([Pull Request](https://github.com/rails/rails/pull/23980)) + +* Deprecated env method on controller instances. + ([commit](https://github.com/rails/rails/commit/05934d24aff62d66fc62621aa38dae6456e276be)) + +* `ActionDispatch::ParamsParser` is deprecated and was removed from the + middleware stack. To configure the parameter parsers use + `ActionDispatch::Request.parameter_parsers=`. + ([commit](https://github.com/rails/rails/commit/38d2bf5fd1f3e014f2397898d371c339baa627b1), + [commit](https://github.com/rails/rails/commit/5ed38014811d4ce6d6f957510b9153938370173b)) + +### Notable changes + +* Added `ActionController::Renderer` to render arbitrary templates + outside controller actions. + ([Pull Request](https://github.com/rails/rails/pull/18546)) + +* Migrating to keyword arguments syntax in `ActionController::TestCase` and + `ActionDispatch::Integration` HTTP request methods. + ([Pull Request](https://github.com/rails/rails/pull/18323)) + +* Added `http_cache_forever` to Action Controller, so we can cache a response + that never gets expired. + ([Pull Request](https://github.com/rails/rails/pull/18394)) + +* Provide friendlier access to request variants. + ([Pull Request](https://github.com/rails/rails/pull/18939)) + +* For actions with no corresponding templates, render `head :no_content` + instead of raising an error. + ([Pull Request](https://github.com/rails/rails/pull/19377)) + +* Added the ability to override default form builder for a controller. + ([Pull Request](https://github.com/rails/rails/pull/19736)) + +* Added support for API only apps. + `ActionController::API` is added as a replacement of + `ActionController::Base` for this kind of applications. + ([Pull Request](https://github.com/rails/rails/pull/19832)) + +* Make `ActionController::Parameters` no longer inherits from + `HashWithIndifferentAccess`. + ([Pull Request](https://github.com/rails/rails/pull/20868)) + +* Make it easier to opt in to `config.force_ssl` and `config.ssl_options` by + making them less dangerous to try and easier to disable. + ([Pull Request](https://github.com/rails/rails/pull/21520)) + +* Added the ability of returning arbitrary headers to `ActionDispatch::Static`. + ([Pull Request](https://github.com/rails/rails/pull/19135)) + +* Changed the `protect_from_forgery` prepend default to `false`. + ([commit](https://github.com/rails/rails/commit/39794037817703575c35a75f1961b01b83791191)) + +* `ActionController::TestCase` will be moved to its own gem in Rails 5.1. Use + `ActionDispatch::IntegrationTest` instead. + ([commit](https://github.com/rails/rails/commit/4414c5d1795e815b102571425974a8b1d46d932d)) + +* Rails generates weak ETags by default. + ([Pull Request](https://github.com/rails/rails/pull/17573)) + +* Controller actions without an explicit `render` call and with no + corresponding templates will render `head :no_content` implicitly + instead of raising an error. + (Pull Request [1](https://github.com/rails/rails/pull/19377), + [2](https://github.com/rails/rails/pull/23827)) + +* Added an option for per-form CSRF tokens. + ([Pull Request](https://github.com/rails/rails/pull/22275)) + +* Added request encoding and response parsing to integration tests. + ([Pull Request](https://github.com/rails/rails/pull/21671)) + +* Add `ActionController#helpers` to get access to the view context + at the controller level. + ([Pull Request](https://github.com/rails/rails/pull/24866)) + +* Discarded flash messages get removed before storing into session. + ([Pull Request](https://github.com/rails/rails/pull/18721)) + +* Added support for passing collection of records to `fresh_when` and + `stale?`. + ([Pull Request](https://github.com/rails/rails/pull/18374)) + +* `ActionController::Live` became an `ActiveSupport::Concern`. That + means it can't be just included in other modules without extending + them with `ActiveSupport::Concern` or `ActionController::Live` + won't take effect in production. Some people may be using another + module to include some special `Warden`/`Devise` authentication + failure handling code as well since the middleware can't catch a + `:warden` thrown by a spawned thread which is the case when using + `ActionController::Live`. + ([More details in this issue](https://github.com/rails/rails/issues/25581)) + +* Introduce `Response#strong_etag=` and `#weak_etag=` and analogous + options for `fresh_when` and `stale?`. + ([Pull Request](https://github.com/rails/rails/pull/24387)) + +Action View +------------- + +Please refer to the [Changelog][action-view] for detailed changes. + +### Removals + +* Removed deprecated `AbstractController::Base::parent_prefixes`. + ([commit](https://github.com/rails/rails/commit/34bcbcf35701ca44be559ff391535c0dd865c333)) + +* Removed `ActionView::Helpers::RecordTagHelper`, this functionality + has been extracted to the + [record_tag_helper](https://github.com/rails/record_tag_helper) gem. + ([Pull Request](https://github.com/rails/rails/pull/18411)) + +* Removed `:rescue_format` option for `translate` helper since it's no longer + supported by I18n. + ([Pull Request](https://github.com/rails/rails/pull/20019)) + +### Notable Changes + +* Changed the default template handler from `ERB` to `Raw`. + ([commit](https://github.com/rails/rails/commit/4be859f0fdf7b3059a28d03c279f03f5938efc80)) + +* Collection rendering can cache and fetches multiple partials at once. + ([Pull Request](https://github.com/rails/rails/pull/18948), + [commit](https://github.com/rails/rails/commit/e93f0f0f133717f9b06b1eaefd3442bd0ff43985)) + +* Added wildcard matching to explicit dependencies. + ([Pull Request](https://github.com/rails/rails/pull/20904)) + +* Make `disable_with` the default behavior for submit tags. Disables the + button on submit to prevent double submits. + ([Pull Request](https://github.com/rails/rails/pull/21135)) + +* Partial template name no longer has to be a valid Ruby identifier. + ([commit](https://github.com/rails/rails/commit/da9038e)) + +* The `datetime_tag` helper now generates an input tag with the type of + `datetime-local`. + ([Pull Request](https://github.com/rails/rails/pull/25469)) + +* Allow blocks while rendering with the `render partial:` helper. + ([Pull Request](https://github.com/rails/rails/pull/17974)) + +Action Mailer +------------- + +Please refer to the [Changelog][action-mailer] for detailed changes. + +### Removals + +* Removed deprecated `*_path` helpers in email views. + ([commit](https://github.com/rails/rails/commit/d282125a18c1697a9b5bb775628a2db239142ac7)) + +* Removed deprecated `deliver` and `deliver!` methods. + ([commit](https://github.com/rails/rails/commit/755dcd0691f74079c24196135f89b917062b0715)) + +### Notable changes + +* Template lookup now respects default locale and I18n fallbacks. + ([commit](https://github.com/rails/rails/commit/ecb1981b)) + +* Added `_mailer` suffix to mailers created via generator, following the same + naming convention used in controllers and jobs. + ([Pull Request](https://github.com/rails/rails/pull/18074)) + +* Added `assert_enqueued_emails` and `assert_no_enqueued_emails`. + ([Pull Request](https://github.com/rails/rails/pull/18403)) + +* Added `config.action_mailer.deliver_later_queue_name` configuration to set + the mailer queue name. + ([Pull Request](https://github.com/rails/rails/pull/18587)) + +* Added support for fragment caching in Action Mailer views. + Added new config option `config.action_mailer.perform_caching` to determine + whether your templates should perform caching or not. + ([Pull Request](https://github.com/rails/rails/pull/22825)) + + +Active Record +------------- + +Please refer to the [Changelog][active-record] for detailed changes. + +### Removals + +* Removed deprecated behavior allowing nested arrays to be passed as query + values. ([Pull Request](https://github.com/rails/rails/pull/17919)) + +* Removed deprecated `ActiveRecord::Tasks::DatabaseTasks#load_schema`. This + method was replaced by `ActiveRecord::Tasks::DatabaseTasks#load_schema_for`. + ([commit](https://github.com/rails/rails/commit/ad783136d747f73329350b9bb5a5e17c8f8800da)) + +* Removed deprecated `serialized_attributes`. + ([commit](https://github.com/rails/rails/commit/82043ab53cb186d59b1b3be06122861758f814b2)) + +* Removed deprecated automatic counter caches on `has_many :through`. + ([commit](https://github.com/rails/rails/commit/87c8ce340c6c83342df988df247e9035393ed7a0)) + +* Removed deprecated `sanitize_sql_hash_for_conditions`. + ([commit](https://github.com/rails/rails/commit/3a59dd212315ebb9bae8338b98af259ac00bbef3)) + +* Removed deprecated `Reflection#source_macro`. + ([commit](https://github.com/rails/rails/commit/ede8c199a85cfbb6457d5630ec1e285e5ec49313)) + +* Removed deprecated `symbolized_base_class` and `symbolized_sti_name`. + ([commit](https://github.com/rails/rails/commit/9013e28e52eba3a6ffcede26f85df48d264b8951)) + +* Removed deprecated `ActiveRecord::Base.disable_implicit_join_references=`. + ([commit](https://github.com/rails/rails/commit/0fbd1fc888ffb8cbe1191193bf86933110693dfc)) + +* Removed deprecated access to connection specification using a string accessor. + ([commit](https://github.com/rails/rails/commit/efdc20f36ccc37afbb2705eb9acca76dd8aabd4f)) + +* Removed deprecated support to preload instance-dependent associations. + ([commit](https://github.com/rails/rails/commit/4ed97979d14c5e92eb212b1a629da0a214084078)) + +* Removed deprecated support for PostgreSQL ranges with exclusive lower bounds. + ([commit](https://github.com/rails/rails/commit/a076256d63f64d194b8f634890527a5ed2651115)) + +* Removed deprecation when modifying a relation with cached Arel. + This raises an `ImmutableRelation` error instead. + ([commit](https://github.com/rails/rails/commit/3ae98181433dda1b5e19910e107494762512a86c)) + +* Removed `ActiveRecord::Serialization::XmlSerializer` from core. This feature + has been extracted into the + [activemodel-serializers-xml](https://github.com/rails/activemodel-serializers-xml) + gem. ([Pull Request](https://github.com/rails/rails/pull/21161)) + +* Removed support for the legacy `mysql` database adapter from core. Most users should + be able to use `mysql2`. It will be converted to a separate gem when we find someone + to maintain it. ([Pull Request 1](https://github.com/rails/rails/pull/22642), + [Pull Request 2](https://github.com/rails/rails/pull/22715)) + +* Removed support for the `protected_attributes` gem. + ([commit](https://github.com/rails/rails/commit/f4fbc0301021f13ae05c8e941c8efc4ae351fdf9)) + +* Removed support for PostgreSQL versions below 9.1. + ([Pull Request](https://github.com/rails/rails/pull/23434)) + +* Removed support for `activerecord-deprecated_finders` gem. + ([commit](https://github.com/rails/rails/commit/78dab2a8569408658542e462a957ea5a35aa4679)) + +* Removed `ActiveRecord::ConnectionAdapters::Column::TRUE_VALUES` constant. + ([commit](https://github.com/rails/rails/commit/a502703c3d2151d4d3b421b29fefdac5ad05df61)) + +### Deprecations + +* Deprecated passing a class as a value in a query. Users should pass strings + instead. ([Pull Request](https://github.com/rails/rails/pull/17916)) + +* Deprecated returning `false` as a way to halt Active Record callback + chains. The recommended way is to + `throw(:abort)`. ([Pull Request](https://github.com/rails/rails/pull/17227)) + +* Deprecated `ActiveRecord::Base.errors_in_transactional_callbacks=`. + ([commit](https://github.com/rails/rails/commit/07d3d402341e81ada0214f2cb2be1da69eadfe72)) + +* Deprecated `Relation#uniq` use `Relation#distinct` instead. + ([commit](https://github.com/rails/rails/commit/adfab2dcf4003ca564d78d4425566dd2d9cd8b4f)) + +* Deprecated the PostgreSQL `:point` type in favor of a new one which will return + `Point` objects instead of an `Array` + ([Pull Request](https://github.com/rails/rails/pull/20448)) + +* Deprecated force association reload by passing a truthy argument to + association method. + ([Pull Request](https://github.com/rails/rails/pull/20888)) + +* Deprecated the keys for association `restrict_dependent_destroy` errors in favor + of new key names. + ([Pull Request](https://github.com/rails/rails/pull/20668)) + +* Synchronize behavior of `#tables`. + ([Pull Request](https://github.com/rails/rails/pull/21601)) + +* Deprecated `SchemaCache#tables`, `SchemaCache#table_exists?` and + `SchemaCache#clear_table_cache!` in favor of their new data source + counterparts. + ([Pull Request](https://github.com/rails/rails/pull/21715)) + +* Deprecated `connection.tables` on the SQLite3 and MySQL adapters. + ([Pull Request](https://github.com/rails/rails/pull/21601)) + +* Deprecated passing arguments to `#tables` - the `#tables` method of some + adapters (mysql2, sqlite3) would return both tables and views while others + (postgresql) just return tables. To make their behavior consistent, + `#tables` will return only tables in the future. + ([Pull Request](https://github.com/rails/rails/pull/21601)) + +* Deprecated `table_exists?` - The `#table_exists?` method would check both + tables and views. To make their behavior consistent with `#tables`, + `#table_exists?` will check only tables in the future. + ([Pull Request](https://github.com/rails/rails/pull/21601)) + +* Deprecate sending the `offset` argument to `find_nth`. Please use the + `offset` method on relation instead. + ([Pull Request](https://github.com/rails/rails/pull/22053)) + +* Deprecated `{insert|update|delete}_sql` in `DatabaseStatements`. + Use the `{insert|update|delete}` public methods instead. + ([Pull Request](https://github.com/rails/rails/pull/23086)) + +* Deprecated `use_transactional_fixtures` in favor of + `use_transactional_tests` for more clarity. + ([Pull Request](https://github.com/rails/rails/pull/19282)) + +* Deprecated passing a column to `ActiveRecord::Connection#quote`. + ([commit](https://github.com/rails/rails/commit/7bb620869725ad6de603f6a5393ee17df13aa96c)) + +* Added an option `end` to `find_in_batches` that complements the `start` + parameter to specify where to stop batch processing. + ([Pull Request](https://github.com/rails/rails/pull/12257)) + + +### Notable changes + +* Added a `foreign_key` option to `references` while creating the table. + ([commit](https://github.com/rails/rails/commit/99a6f9e60ea55924b44f894a16f8de0162cf2702)) + +* New attributes + API. ([commit](https://github.com/rails/rails/commit/8c752c7ac739d5a86d4136ab1e9d0142c4041e58)) + +* Added `:_prefix`/`:_suffix` option to `enum` definition. + ([Pull Request](https://github.com/rails/rails/pull/19813), + [Pull Request](https://github.com/rails/rails/pull/20999)) + +* Added `#cache_key` to `ActiveRecord::Relation`. + ([Pull Request](https://github.com/rails/rails/pull/20884)) + +* Changed the default `null` value for `timestamps` to `false`. + ([commit](https://github.com/rails/rails/commit/a939506f297b667291480f26fa32a373a18ae06a)) + +* Added `ActiveRecord::SecureToken` in order to encapsulate generation of + unique tokens for attributes in a model using `SecureRandom`. + ([Pull Request](https://github.com/rails/rails/pull/18217)) + +* Added `:if_exists` option for `drop_table`. + ([Pull Request](https://github.com/rails/rails/pull/18597)) + +* Added `ActiveRecord::Base#accessed_fields`, which can be used to quickly + discover which fields were read from a model when you are looking to only + select the data you need from the database. + ([commit](https://github.com/rails/rails/commit/be9b68038e83a617eb38c26147659162e4ac3d2c)) + +* Added the `#or` method on `ActiveRecord::Relation`, allowing use of the OR + operator to combine WHERE or HAVING clauses. + ([commit](https://github.com/rails/rails/commit/b0b37942d729b6bdcd2e3178eda7fa1de203b3d0)) + +* Added `ActiveRecord::Base.suppress` to prevent the receiver from being saved + during the given block. + ([Pull Request](https://github.com/rails/rails/pull/18910)) + +* `belongs_to` will now trigger a validation error by default if the + association is not present. You can turn this off on a per-association basis + with `optional: true`. Also deprecate `required` option in favor of `optional` + for `belongs_to`. + ([Pull Request](https://github.com/rails/rails/pull/18937)) + +* Added `config.active_record.dump_schemas` to configure the behavior of + `db:structure:dump`. + ([Pull Request](https://github.com/rails/rails/pull/19347)) + +* Added `config.active_record.warn_on_records_fetched_greater_than` option. + ([Pull Request](https://github.com/rails/rails/pull/18846)) + +* Added a native JSON data type support in MySQL. + ([Pull Request](https://github.com/rails/rails/pull/21110)) + +* Added support for dropping indexes concurrently in PostgreSQL. + ([Pull Request](https://github.com/rails/rails/pull/21317)) + +* Added `#views` and `#view_exists?` methods on connection adapters. + ([Pull Request](https://github.com/rails/rails/pull/21609)) + +* Added `ActiveRecord::Base.ignored_columns` to make some columns + invisible from Active Record. + ([Pull Request](https://github.com/rails/rails/pull/21720)) + +* Added `connection.data_sources` and `connection.data_source_exists?`. + These methods determine what relations can be used to back Active Record + models (usually tables and views). + ([Pull Request](https://github.com/rails/rails/pull/21715)) + +* Allow fixtures files to set the model class in the YAML file itself. + ([Pull Request](https://github.com/rails/rails/pull/20574)) + +* Added ability to default to `uuid` as primary key when generating database + migrations. ([Pull Request](https://github.com/rails/rails/pull/21762)) + +* Added `ActiveRecord::Relation#left_joins` and + `ActiveRecord::Relation#left_outer_joins`. + ([Pull Request](https://github.com/rails/rails/pull/12071)) + +* Added `after_{create,update,delete}_commit` callbacks. + ([Pull Request](https://github.com/rails/rails/pull/22516)) + +* Version the API presented to migration classes, so we can change parameter + defaults without breaking existing migrations, or forcing them to be + rewritten through a deprecation cycle. + ([Pull Request](https://github.com/rails/rails/pull/21538)) + +* `ApplicationRecord` is a new superclass for all app models, analogous to app + controllers subclassing `ApplicationController` instead of + `ActionController::Base`. This gives apps a single spot to configure app-wide + model behavior. + ([Pull Request](https://github.com/rails/rails/pull/22567)) + +* Added ActiveRecord `#second_to_last` and `#third_to_last` methods. + ([Pull Request](https://github.com/rails/rails/pull/23583)) + +* Added ability to annotate database objects (tables, columns, indexes) + with comments stored in database metadata for PostgreSQL & MySQL. + ([Pull Request](https://github.com/rails/rails/pull/22911)) + +* Added prepared statements support to `mysql2` adapter, for mysql2 0.4.4+, + Previously this was only supported on the deprecated `mysql` legacy adapter. + To enable, set `prepared_statements: true` in `config/database.yml`. + ([Pull Request](https://github.com/rails/rails/pull/23461)) + +* Added ability to call `ActionRecord::Relation#update` on relation objects + which will run validations on callbacks on all objects in the relation. + ([Pull Request](https://github.com/rails/rails/pull/11898)) + +* Added `:touch` option to the `save` method so that records can be saved without + updating timestamps. + ([Pull Request](https://github.com/rails/rails/pull/18225)) + +* Added expression indexes and operator classes support for PostgreSQL. + ([commit](https://github.com/rails/rails/commit/edc2b7718725016e988089b5fb6d6fb9d6e16882)) + +* Added `:index_errors` option to add indexes to errors of nested attributes. + ([Pull Request](https://github.com/rails/rails/pull/19686)) + +* Added support for bidirectional destroy dependencies. + ([Pull Request](https://github.com/rails/rails/pull/18548)) + +* Added support for `after_commit` callbacks in transactional tests. + ([Pull Request](https://github.com/rails/rails/pull/18458)) + +* Added `foreign_key_exists?` method to see if a foreign key exists on a table + or not. + ([Pull Request](https://github.com/rails/rails/pull/18662)) + +* Added `:time` option to `touch` method to touch records with different time + than the current time. + ([Pull Request](https://github.com/rails/rails/pull/18956)) + +* Change transaction callbacks to not swallow errors. + Before this change any errors raised inside a transaction callback + were getting rescued and printed in the logs, unless you used + the (newly deprecated) `raise_in_transactional_callbacks = true` option. + + Now these errors are not rescued anymore and just bubble up, matching the + behavior of other callbacks. + ([commit](https://github.com/rails/rails/commit/07d3d402341e81ada0214f2cb2be1da69eadfe72)) + +Active Model +------------ + +Please refer to the [Changelog][active-model] for detailed changes. + +### Removals + +* Removed deprecated `ActiveModel::Dirty#reset_#{attribute}` and + `ActiveModel::Dirty#reset_changes`. + ([Pull Request](https://github.com/rails/rails/commit/37175a24bd508e2983247ec5d011d57df836c743)) + +* Removed XML serialization. This feature has been extracted into the + [activemodel-serializers-xml](https://github.com/rails/activemodel-serializers-xml) gem. + ([Pull Request](https://github.com/rails/rails/pull/21161)) + +* Removed `ActionController::ModelNaming` module. + ([Pull Request](https://github.com/rails/rails/pull/18194)) + +### Deprecations + +* Deprecated returning `false` as a way to halt Active Model and + `ActiveModel::Validations` callback chains. The recommended way is to + `throw(:abort)`. ([Pull Request](https://github.com/rails/rails/pull/17227)) + +* Deprecated `ActiveModel::Errors#get`, `ActiveModel::Errors#set` and + `ActiveModel::Errors#[]=` methods that have inconsistent behavior. + ([Pull Request](https://github.com/rails/rails/pull/18634)) + +* Deprecated the `:tokenizer` option for `validates_length_of`, in favor of + plain Ruby. + ([Pull Request](https://github.com/rails/rails/pull/19585)) + +* Deprecated `ActiveModel::Errors#add_on_empty` and `ActiveModel::Errors#add_on_blank` + with no replacement. + ([Pull Request](https://github.com/rails/rails/pull/18996)) + +### Notable changes + +* Added `ActiveModel::Errors#details` to determine what validator has failed. + ([Pull Request](https://github.com/rails/rails/pull/18322)) + +* Extracted `ActiveRecord::AttributeAssignment` to `ActiveModel::AttributeAssignment` + allowing to use it for any object as an includable module. + ([Pull Request](https://github.com/rails/rails/pull/10776)) + +* Added `ActiveModel::Dirty#[attr_name]_previously_changed?` and + `ActiveModel::Dirty#[attr_name]_previous_change` to improve access + to recorded changes after the model has been saved. + ([Pull Request](https://github.com/rails/rails/pull/19847)) + +* Validate multiple contexts on `valid?` and `invalid?` at once. + ([Pull Request](https://github.com/rails/rails/pull/21069)) + +* Change `validates_acceptance_of` to accept `true` as default value + apart from `1`. + ([Pull Request](https://github.com/rails/rails/pull/18439)) + +Active Job +----------- + +Please refer to the [Changelog][active-job] for detailed changes. + +### Notable changes + +* `ActiveJob::Base.deserialize` delegates to the job class. This allows jobs + to attach arbitrary metadata when they get serialized and read it back when + they get performed. + ([Pull Request](https://github.com/rails/rails/pull/18260)) + +* Add ability to configure the queue adapter on a per job basis without + affecting each other. + ([Pull Request](https://github.com/rails/rails/pull/16992)) + +* A generated job now inherits from `app/jobs/application_job.rb` by default. + ([Pull Request](https://github.com/rails/rails/pull/19034)) + +* Allow `DelayedJob`, `Sidekiq`, `qu`, `que`, and `queue_classic` to report + the job id back to `ActiveJob::Base` as `provider_job_id`. + ([Pull Request](https://github.com/rails/rails/pull/20064), + [Pull Request](https://github.com/rails/rails/pull/20056), + [commit](https://github.com/rails/rails/commit/68e3279163d06e6b04e043f91c9470e9259bbbe0)) + +* Implement a simple `AsyncJob` processor and associated `AsyncAdapter` that + queue jobs to a `concurrent-ruby` thread pool. + ([Pull Request](https://github.com/rails/rails/pull/21257)) + +* Change the default adapter from inline to async. It's a better default as + tests will then not mistakenly come to rely on behavior happening + synchronously. + ([commit](https://github.com/rails/rails/commit/625baa69d14881ac49ba2e5c7d9cac4b222d7022)) + +Active Support +-------------- + +Please refer to the [Changelog][active-support] for detailed changes. + +### Removals + +* Removed deprecated `ActiveSupport::JSON::Encoding::CircularReferenceError`. + ([commit](https://github.com/rails/rails/commit/d6e06ea8275cdc3f126f926ed9b5349fde374b10)) + +* Removed deprecated methods `ActiveSupport::JSON::Encoding.encode_big_decimal_as_string=` + and `ActiveSupport::JSON::Encoding.encode_big_decimal_as_string`. + ([commit](https://github.com/rails/rails/commit/c8019c0611791b2716c6bed48ef8dcb177b7869c)) + +* Removed deprecated `ActiveSupport::SafeBuffer#prepend`. + ([commit](https://github.com/rails/rails/commit/e1c8b9f688c56aaedac9466a4343df955b4a67ec)) + +* Removed deprecated methods from `Kernel`. `silence_stderr`, `silence_stream`, + `capture` and `quietly`. + ([commit](https://github.com/rails/rails/commit/481e49c64f790e46f4aff3ed539ed227d2eb46cb)) + +* Removed deprecated `active_support/core_ext/big_decimal/yaml_conversions` + file. + ([commit](https://github.com/rails/rails/commit/98ea19925d6db642731741c3b91bd085fac92241)) + +* Removed deprecated methods `ActiveSupport::Cache::Store.instrument` and + `ActiveSupport::Cache::Store.instrument=`. + ([commit](https://github.com/rails/rails/commit/a3ce6ca30ed0e77496c63781af596b149687b6d7)) + +* Removed deprecated `Class#superclass_delegating_accessor`. + Use `Class#class_attribute` instead. + ([Pull Request](https://github.com/rails/rails/pull/16938)) + +* Removed deprecated `ThreadSafe::Cache`. Use `Concurrent::Map` instead. + ([Pull Request](https://github.com/rails/rails/pull/21679)) + +* Removed `Object#itself` as it is implemented in Ruby 2.2. + ([Pull Request](https://github.com/rails/rails/pull/18244)) + +### Deprecations + +* Deprecated `MissingSourceFile` in favor of `LoadError`. + ([commit](https://github.com/rails/rails/commit/734d97d2)) + +* Deprecated `alias_method_chain` in favour of `Module#prepend` introduced in + Ruby 2.0. + ([Pull Request](https://github.com/rails/rails/pull/19434)) + +* Deprecated `ActiveSupport::Concurrency::Latch` in favor of + `Concurrent::CountDownLatch` from concurrent-ruby. + ([Pull Request](https://github.com/rails/rails/pull/20866)) + +* Deprecated `:prefix` option of `number_to_human_size` with no replacement. + ([Pull Request](https://github.com/rails/rails/pull/21191)) + +* Deprecated `Module#qualified_const_` in favour of the builtin + `Module#const_` methods. + ([Pull Request](https://github.com/rails/rails/pull/17845)) + +* Deprecated passing string to define callback. + ([Pull Request](https://github.com/rails/rails/pull/22598)) + +* Deprecated `ActiveSupport::Cache::Store#namespaced_key`, + `ActiveSupport::Cache::MemCachedStore#escape_key`, and + `ActiveSupport::Cache::FileStore#key_file_path`. + Use `normalize_key` instead. + ([Pull Request](https://github.com/rails/rails/pull/22215), + [commit](https://github.com/rails/rails/commit/a8f773b0)) + +* Deprecated `ActiveSupport::Cache::LocaleCache#set_cache_value` in favor of `write_cache_value`. + ([Pull Request](https://github.com/rails/rails/pull/22215)) + +* Deprecated passing arguments to `assert_nothing_raised`. + ([Pull Request](https://github.com/rails/rails/pull/23789)) + +* Deprecated `Module.local_constants` in favor of `Module.constants(false)`. + ([Pull Request](https://github.com/rails/rails/pull/23936)) + + +### Notable changes + +* Added `#verified` and `#valid_message?` methods to + `ActiveSupport::MessageVerifier`. + ([Pull Request](https://github.com/rails/rails/pull/17727)) + +* Changed the way in which callback chains can be halted. The preferred method + to halt a callback chain from now on is to explicitly `throw(:abort)`. + ([Pull Request](https://github.com/rails/rails/pull/17227)) + +* New config option + `config.active_support.halt_callback_chains_on_return_false` to specify + whether ActiveRecord, ActiveModel and ActiveModel::Validations callback + chains can be halted by returning `false` in a 'before' callback. + ([Pull Request](https://github.com/rails/rails/pull/17227)) + +* Changed the default test order from `:sorted` to `:random`. + ([commit](https://github.com/rails/rails/commit/5f777e4b5ee2e3e8e6fd0e2a208ec2a4d25a960d)) + +* Added `#on_weekend?`, `#on_weekday?`, `#next_weekday`, `#prev_weekday` methods to `Date`, + `Time`, and `DateTime`. + ([Pull Request](https://github.com/rails/rails/pull/18335), + [Pull Request](https://github.com/rails/rails/pull/23687)) + +* Added `same_time` option to `#next_week` and `#prev_week` for `Date`, `Time`, + and `DateTime`. + ([Pull Request](https://github.com/rails/rails/pull/18335)) + +* Added `#prev_day` and `#next_day` counterparts to `#yesterday` and + `#tomorrow` for `Date`, `Time`, and `DateTime`. + ([Pull Request](https://github.com/rails/rails/pull/18335)) + +* Added `SecureRandom.base58` for generation of random base58 strings. + ([commit](https://github.com/rails/rails/commit/b1093977110f18ae0cafe56c3d99fc22a7d54d1b)) + +* Added `file_fixture` to `ActiveSupport::TestCase`. + It provides a simple mechanism to access sample files in your test cases. + ([Pull Request](https://github.com/rails/rails/pull/18658)) + +* Added `#without` on `Enumerable` and `Array` to return a copy of an + enumerable without the specified elements. + ([Pull Request](https://github.com/rails/rails/pull/19157)) + +* Added `ActiveSupport::ArrayInquirer` and `Array#inquiry`. + ([Pull Request](https://github.com/rails/rails/pull/18939)) + +* Added `ActiveSupport::TimeZone#strptime` to allow parsing times as if + from a given timezone. + ([commit](https://github.com/rails/rails/commit/a5e507fa0b8180c3d97458a9b86c195e9857d8f6)) + +* Added `Integer#positive?` and `Integer#negative?` query methods + in the vein of `Integer#zero?`. + ([commit](https://github.com/rails/rails/commit/e54277a45da3c86fecdfa930663d7692fd083daa)) + +* Added a bang version to `ActiveSupport::OrderedOptions` get methods which will raise + an `KeyError` if the value is `.blank?`. + ([Pull Request](https://github.com/rails/rails/pull/20208)) + +* Added `Time.days_in_year` to return the number of days in the given year, or the + current year if no argument is provided. + ([commit](https://github.com/rails/rails/commit/2f4f4d2cf1e4c5a442459fc250daf66186d110fa)) + +* Added an evented file watcher to asynchronously detect changes in the + application source code, routes, locales, etc. + ([Pull Request](https://github.com/rails/rails/pull/22254)) + +* Added thread_m/cattr_accessor/reader/writer suite of methods for declaring + class and module variables that live per-thread. + ([Pull Request](https://github.com/rails/rails/pull/22630)) + +* Added `Array#second_to_last` and `Array#third_to_last` methods. + ([Pull Request](https://github.com/rails/rails/pull/23583)) + +* Publish `ActiveSupport::Executor` and `ActiveSupport::Reloader` APIs to allow + components and libraries to manage, and participate in, the execution of + application code, and the application reloading process. + ([Pull Request](https://github.com/rails/rails/pull/23807)) + +* `ActiveSupport::Duration` now supports ISO8601 formatting and parsing. + ([Pull Request](https://github.com/rails/rails/pull/16917)) + +* `ActiveSupport::JSON.decode` now supports parsing ISO8601 local times when + `parse_json_times` is enabled. + ([Pull Request](https://github.com/rails/rails/pull/23011)) + +* `ActiveSupport::JSON.decode` now return `Date` objects for date strings. + ([Pull Request](https://github.com/rails/rails/pull/23011)) + +* Added ability to `TaggedLogging` to allow loggers to be instantiated multiple + times so that they don't share tags with each other. + ([Pull Request](https://github.com/rails/rails/pull/9065)) + +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. + +[railties]: https://github.com/rails/rails/blob/5-0-stable/railties/CHANGELOG.md +[action-pack]: https://github.com/rails/rails/blob/5-0-stable/actionpack/CHANGELOG.md +[action-view]: https://github.com/rails/rails/blob/5-0-stable/actionview/CHANGELOG.md +[action-mailer]: https://github.com/rails/rails/blob/5-0-stable/actionmailer/CHANGELOG.md +[action-cable]: https://github.com/rails/rails/blob/5-0-stable/actioncable/CHANGELOG.md +[active-record]: https://github.com/rails/rails/blob/5-0-stable/activerecord/CHANGELOG.md +[active-model]: https://github.com/rails/rails/blob/5-0-stable/activemodel/CHANGELOG.md +[active-support]: https://github.com/rails/rails/blob/5-0-stable/activesupport/CHANGELOG.md +[active-job]: https://github.com/rails/rails/blob/5-0-stable/activejob/CHANGELOG.md diff --git a/guides/source/5_1_release_notes.md b/guides/source/5_1_release_notes.md new file mode 100644 index 0000000000..852d04b1f6 --- /dev/null +++ b/guides/source/5_1_release_notes.md @@ -0,0 +1,659 @@ +**DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON http://guides.rubyonrails.org.** + +Ruby on Rails 5.1 Release Notes +=============================== + +Highlights in Rails 5.1: + +* Yarn Support +* Optional Webpack support +* jQuery no longer a default dependency +* System tests +* Encrypted secrets +* Parameterized mailers +* Direct & resolved routes +* Unification of form_for and form_tag into form_with + +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/5-1-stable) in the main Rails +repository on GitHub. + +-------------------------------------------------------------------------------- + +Upgrading to Rails 5.1 +---------------------- + +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 5.0 in case you +haven't and make sure your application still runs as expected before attempting +an update to Rails 5.1. 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-5-0-to-rails-5-1) +guide. + + +Major Features +-------------- + +### Yarn Support + +[Pull Request](https://github.com/rails/rails/pull/26836) + +Rails 5.1 allows managing JavaScript dependencies +from NPM via Yarn. This will make it easy to use libraries like React, VueJS +or any other library from NPM world. The Yarn support is integrated with +the asset pipeline so that all dependencies will work seamlessly with the +Rails 5.1 app. + +### Optional Webpack support + +[Pull Request](https://github.com/rails/rails/pull/27288) + +Rails apps can integrate with [Webpack](https://webpack.js.org/), a JavaScript +asset bundler, more easily using the new [Webpacker](https://github.com/rails/webpacker) +gem. Use the `--webpack` flag when generating new applications to enable Webpack +integration. + +This is fully compatible with the asset pipeline, which you can continue to use for +images, fonts, sounds, and other assets. You can even have some JavaScript code +managed by the asset pipeline, and other code processed via Webpack. All of this is managed +by Yarn, which is enabled by default. + +### jQuery no longer a default dependency + +[Pull Request](https://github.com/rails/rails/pull/27113) + +jQuery was required by default in earlier versions of Rails to provide features +like `data-remote`, `data-confirm` and other parts of Rails' Unobtrusive JavaScript +offerings. It is no longer required, as the UJS has been rewritten to use plain, +vanilla JavaScript. This code now ships inside of Action View as +`rails-ujs`. + +You can still use jQuery if needed, but it is no longer required by default. + +### System tests + +[Pull Request](https://github.com/rails/rails/pull/26703) + +Rails 5.1 has baked-in support for writing Capybara tests, in the form of +System tests. You no longer need to worry about configuring Capybara and +database cleaning strategies for such tests. Rails 5.1 provides a wrapper +for running tests in Chrome with additional features such as failure +screenshots. + +### Encrypted secrets + +[Pull Request](https://github.com/rails/rails/pull/28038) + +Rails now allows management of application secrets in a secure way, +inspired by the [sekrets](https://github.com/ahoward/sekrets) gem. + +Run `bin/rails secrets:setup` to setup a new encrypted secrets file. This will +also generate a master key, which must be stored outside of the repository. The +secrets themselves can then be safely checked into the revision control system, +in an encrypted form. + +Secrets will be decrypted in production, using a key stored either in the +`RAILS_MASTER_KEY` environment variable, or in a key file. + +### Parameterized mailers + +[Pull Request](https://github.com/rails/rails/pull/27825) + +Allows specifying common parameters used for all methods in a mailer class in +order to share instance variables, headers and other common setup. + +``` ruby +class InvitationsMailer < ApplicationMailer + before_action { @inviter, @invitee = params[:inviter], params[:invitee] } + before_action { @account = params[:inviter].account } + + def account_invitation + mail subject: "#{@inviter.name} invited you to their Basecamp (#{@account.name})" + end +end + +InvitationsMailer.with(inviter: person_a, invitee: person_b) + .account_invitation.deliver_later +``` + +### Direct & resolved routes + +[Pull Request](https://github.com/rails/rails/pull/23138) + +Rails 5.1 adds two new methods, `resolve` and `direct`, to the routing +DSL. The `resolve` method allows customizing polymorphic mapping of models. + +``` ruby +resource :basket + +resolve("Basket") { [:basket] } +``` + +``` erb +<%= form_for @basket do |form| %> + <!-- basket form --> +<% end %> +``` + +This will generate the singular URL `/basket` instead of the usual `/baskets/:id`. + +The `direct` method allows creation of custom URL helpers. + +``` ruby +direct(:homepage) { "http://www.rubyonrails.org" } + +>> homepage_url +=> "http://www.rubyonrails.org" +``` + +The return value of the block must be a valid argument for the `url_for` +method. So, you can pass a valid string URL, Hash, Array, an +Active Model instance, or an Active Model class. + +``` ruby +direct :commentable do |model| + [ model, anchor: model.dom_id ] +end + +direct :main do + { controller: 'pages', action: 'index', subdomain: 'www' } +end +``` + +### Unification of form_for and form_tag into form_with + +[Pull Request](https://github.com/rails/rails/pull/26976) + +Before Rails 5.1, there were two interfaces for handling HTML forms: +`form_for` for model instances and `form_tag` for custom URLs. + +Rails 5.1 combines both of these interfaces with `form_with`, and +can generate form tags based on URLs, scopes or models. + +Using just a URL: + +``` erb +<%= form_with url: posts_path do |form| %> + <%= form.text_field :title %> +<% end %> + +<%# Will generate %> + +<form action="/posts" method="post" data-remote="true"> + <input type="text" name="title"> +</form> +``` + +Adding a scope prefixes the input field names: + +``` erb +<%= form_with scope: :post, url: posts_path do |form| %> + <%= form.text_field :title %> +<% end %> + +<%# Will generate %> + +<form action="/posts" method="post" data-remote="true"> + <input type="text" name="post[title]"> +</form> +``` + +Using a model infers both the URL and scope: + +``` erb +<%= form_with model: Post.new do |form| %> + <%= form.text_field :title %> +<% end %> + +<%# Will generate %> + +<form action="/posts" method="post" data-remote="true"> + <input type="text" name="post[title]"> +</form> +``` + +An existing model makes an update form and fills out field values: + +``` erb +<%= form_with model: Post.first do |form| %> + <%= form.text_field :title %> +<% end %> + +<%# Will generate %> + +<form action="/posts/1" method="post" data-remote="true"> + <input type="hidden" name="_method" value="patch"> + <input type="text" name="post[title]" value="<the title of the post>"> +</form> +``` + +Incompatibilities +----------------- + +The following changes may require immediate action upon upgrade. + +### Transactional tests with multiple connections + +Transactional tests now wrap all Active Record connections in database +transactions. + +When a test spawns additional threads, and those threads obtain database +connections, those connections are now handled specially: + +The threads will share a single connection, which is inside the managed +transaction. This ensures all threads see the database in the same +state, ignoring the outermost transaction. Previously, such additional +connections were unable to see the fixture rows, for example. + +When a thread enters a nested transaction, it will temporarily obtain +exclusive use of the connection, to maintain isolation. + +If your tests currently rely on obtaining a separate, +outside-of-transaction, connection in a spawned thread, you'll need to +switch to more explicit connection management. + +If your tests spawn threads and those threads interact while also using +explicit database transactions, this change may introduce a deadlock. + +The easy way to opt out of this new behavior is to disable transactional +tests on any test cases it affects. + +Railties +-------- + +Please refer to the [Changelog][railties] for detailed changes. + +### Removals + +* Remove deprecated `config.static_cache_control`. + ([commit](https://github.com/rails/rails/commit/c861decd44198f8d7d774ee6a74194d1ac1a5a13)) + +* Remove deprecated `config.serve_static_files`. + ([commit](https://github.com/rails/rails/commit/0129ca2eeb6d5b2ea8c6e6be38eeb770fe45f1fa)) + +* Remove deprecated file `rails/rack/debugger`. + ([commit](https://github.com/rails/rails/commit/7563bf7b46e6f04e160d664e284a33052f9804b8)) + +* Remove deprecated tasks: `rails:update`, `rails:template`, `rails:template:copy`, + `rails:update:configs` and `rails:update:bin`. + ([commit](https://github.com/rails/rails/commit/f7782812f7e727178e4a743aa2874c078b722eef)) + +* Remove deprecated `CONTROLLER` environment variable for `routes` task. + ([commit](https://github.com/rails/rails/commit/f9ed83321ac1d1902578a0aacdfe55d3db754219)) + +* Remove -j (--javascript) option from `rails new` command. + ([Pull Request](https://github.com/rails/rails/pull/28546)) + +### Notable changes + +* Added a shared section to `config/secrets.yml` that will be loaded for all + environments. + ([commit](https://github.com/rails/rails/commit/e530534265d2c32b5c5f772e81cb9002dcf5e9cf)) + +* The config file `config/secrets.yml` is now loaded in with all keys as symbols. + ([Pull Request](https://github.com/rails/rails/pull/26929)) + +* Removed jquery-rails from default stack. rails-ujs, which is shipped + with Action View, is included as default UJS adapter. + ([Pull Request](https://github.com/rails/rails/pull/27113)) + +* Add Yarn support in new apps with a yarn binstub and package.json. + ([Pull Request](https://github.com/rails/rails/pull/26836)) + +* Add Webpack support in new apps via the `--webpack` option, which will delegate + to the rails/webpacker gem. + ([Pull Request](https://github.com/rails/rails/pull/27288)) + +* Initialize Git repo when generating new app, if option `--skip-git` is not + provided. + ([Pull Request](https://github.com/rails/rails/pull/27632)) + +* Add encrypted secrets in `config/secrets.yml.enc`. + ([Pull Request](https://github.com/rails/rails/pull/28038)) + +* Display railtie class name in `rails initializers`. + ([Pull Request](https://github.com/rails/rails/pull/25257)) + +Action Cable +----------- + +Please refer to the [Changelog][action-cable] for detailed changes. + +### Notable changes + +* Added support for `channel_prefix` to Redis and evented Redis adapters + in `cable.yml` to avoid name collisions when using the same Redis server + with multiple applications. + ([Pull Request](https://github.com/rails/rails/pull/27425)) + +* Add `ActiveSupport::Notifications` hook for broadcasting data. + ([Pull Request](https://github.com/rails/rails/pull/24988)) + +Action Pack +----------- + +Please refer to the [Changelog][action-pack] for detailed changes. + +### Removals + +* Removed support for non-keyword arguments in `#process`, `#get`, `#post`, + `#patch`, `#put`, `#delete`, and `#head` for the `ActionDispatch::IntegrationTest` + and `ActionController::TestCase` classes. + ([Commit](https://github.com/rails/rails/commit/98b8309569a326910a723f521911e54994b112fb), + [Commit](https://github.com/rails/rails/commit/de9542acd56f60d281465a59eac11e15ca8b3323)) + +* Removed deprecated `ActionDispatch::Callbacks.to_prepare` and + `ActionDispatch::Callbacks.to_cleanup`. + ([Commit](https://github.com/rails/rails/commit/3f2b7d60a52ffb2ad2d4fcf889c06b631db1946b)) + +* Removed deprecated methods related to controller filters. + ([Commit](https://github.com/rails/rails/commit/d7be30e8babf5e37a891522869e7b0191b79b757)) + +* Removed deprecated support to `:text` and `:nothing` in `render`. + ([Commit](https://github.com/rails/rails/commit/79a5ea9eadb4d43b62afacedc0706cbe88c54496), + [Commit](https://github.com/rails/rails/commit/57e1c99a280bdc1b324936a690350320a1cd8111)) + +* Removed deprecated support for calling `HashWithIndifferentAccess` methods on `ActionController::Parameters`. + ([Commit](https://github.com/rails/rails/pull/26746/commits/7093ceb480ad6a0a91b511832dad4c6a86981b93)) + +### Deprecations + +* Deprecated `config.action_controller.raise_on_unfiltered_parameters`. + It doesn't have any effect in Rails 5.1. + ([Commit](https://github.com/rails/rails/commit/c6640fb62b10db26004a998d2ece98baede509e5)) + +### Notable changes + +* Added the `direct` and `resolve` methods to the routing DSL. + ([Pull Request](https://github.com/rails/rails/pull/23138)) + +* Added a new `ActionDispatch::SystemTestCase` class to write system tests in + your applications. + ([Pull Request](https://github.com/rails/rails/pull/26703)) + +Action View +------------- + +Please refer to the [Changelog][action-view] for detailed changes. + +### Removals + +* Removed deprecated `#original_exception` in `ActionView::Template::Error`. + ([commit](https://github.com/rails/rails/commit/b9ba263e5aaa151808df058f5babfed016a1879f)) + +* Remove the option `encode_special_chars` misnomer from `strip_tags`. + ([Pull Request](https://github.com/rails/rails/pull/28061)) + +### Deprecations + +* Deprecated Erubis ERB handler in favor of Erubi. + ([Pull Request](https://github.com/rails/rails/pull/27757)) + +### Notable changes + +* Raw template handler (the default template handler in Rails 5) now outputs + HTML-safe strings. + ([commit](https://github.com/rails/rails/commit/1de0df86695f8fa2eeae6b8b46f9b53decfa6ec8)) + +* Change `datetime_field` and `datetime_field_tag` to generate `datetime-local` + fields. + ([Pull Request](https://github.com/rails/rails/pull/28061)) + +* New Builder-style syntax for HTML tags (`tag.div`, `tag.br`, etc.) + ([Pull Request](https://github.com/rails/rails/pull/25543)) + +* Add `form_with` to unify `form_tag` and `form_for` usage. + ([Pull Request](https://github.com/rails/rails/pull/26976)) + +* Add `check_parameters` option to `current_page?`. + ([Pull Request](https://github.com/rails/rails/pull/27549)) + +Action Mailer +------------- + +Please refer to the [Changelog][action-mailer] for detailed changes. + +### Notable changes + +* Allowed setting custom content type when attachments are included + and body is set inline. + ([Pull Request](https://github.com/rails/rails/pull/27227)) + +* Allowed passing lambdas as values to the `default` method. + ([Commit](https://github.com/rails/rails/commit/1cec84ad2ddd843484ed40b1eb7492063ce71baf)) + +* Added support for parameterized invocation of mailers to share before filters and defaults + between different mailer actions. + ([Commit](https://github.com/rails/rails/commit/1cec84ad2ddd843484ed40b1eb7492063ce71baf)) + +* Passed the incoming arguments to the mailer action to `process.action_mailer` event under + an `args` key. + ([Pull Request](https://github.com/rails/rails/pull/27900)) + +Active Record +------------- + +Please refer to the [Changelog][active-record] for detailed changes. + +### Removals + +* Removed support for passing arguments and block at the same time to + `ActiveRecord::QueryMethods#select`. + ([Commit](https://github.com/rails/rails/commit/4fc3366d9d99a0eb19e45ad2bf38534efbf8c8ce)) + +* Removed deprecated `activerecord.errors.messages.restrict_dependent_destroy.one` and + `activerecord.errors.messages.restrict_dependent_destroy.many` i18n scopes. + ([Commit](https://github.com/rails/rails/commit/00e3973a311)) + +* Removed deprecated force reload argument in singular and collection association readers. + ([Commit](https://github.com/rails/rails/commit/09cac8c67af)) + +* Removed deprecated support for passing a column to `#quote`. + ([Commit](https://github.com/rails/rails/commit/e646bad5b7c)) + +* Removed deprecated `name` arguments from `#tables`. + ([Commit](https://github.com/rails/rails/commit/d5be101dd02214468a27b6839ffe338cfe8ef5f3)) + +* Removed deprecated behavior of `#tables` and `#table_exists?` to return tables and views + to return only tables and not views. + ([Commit](https://github.com/rails/rails/commit/5973a984c369a63720c2ac18b71012b8347479a8)) + +* Removed deprecated `original_exception` argument in `ActiveRecord::StatementInvalid#initialize` + and `ActiveRecord::StatementInvalid#original_exception`. + ([Commit](https://github.com/rails/rails/commit/bc6c5df4699d3f6b4a61dd12328f9e0f1bd6cf46)) + +* Removed deprecated support of passing a class as a value in a query. + ([Commit](https://github.com/rails/rails/commit/b4664864c972463c7437ad983832d2582186e886)) + +* Removed deprecated support to query using commas on LIMIT. + ([Commit](https://github.com/rails/rails/commit/fc3e67964753fb5166ccbd2030d7382e1976f393)) + +* Removed deprecated `conditions` parameter from `#destroy_all`. + ([Commit](https://github.com/rails/rails/commit/d31a6d1384cd740c8518d0bf695b550d2a3a4e9b)) + +* Removed deprecated `conditions` parameter from `#delete_all`. + ([Commit](https://github.com/rails/rails/pull/27503/commits/e7381d289e4f8751dcec9553dcb4d32153bd922b)) + +* Removed deprecated method `#load_schema_for` in favor of `#load_schema`. + ([Commit](https://github.com/rails/rails/commit/419e06b56c3b0229f0c72d3e4cdf59d34d8e5545)) + +* Removed deprecated `#raise_in_transactional_callbacks` configuration. + ([Commit](https://github.com/rails/rails/commit/8029f779b8a1dd9848fee0b7967c2e0849bf6e07)) + +* Removed deprecated `#use_transactional_fixtures` configuration. + ([Commit](https://github.com/rails/rails/commit/3955218dc163f61c932ee80af525e7cd440514b3)) + +### Deprecations + +* Deprecated `error_on_ignored_order_or_limit` flag in favor of + `error_on_ignored_order`. + ([Commit](https://github.com/rails/rails/commit/451437c6f57e66cc7586ec966e530493927098c7)) + +* Deprecated `sanitize_conditions` in favor of `sanitize_sql`. + ([Pull Request](https://github.com/rails/rails/pull/25999)) + +* Deprecated `supports_migrations?` on connection adapters. + ([Pull Request](https://github.com/rails/rails/pull/28172)) + +* Deprecated `Migrator.schema_migrations_table_name`, use `SchemaMigration.table_name` instead. + ([Pull Request](https://github.com/rails/rails/pull/28351)) + +* Deprecated using `#quoted_id` in quoting and type casting. + ([Pull Request](https://github.com/rails/rails/pull/27962)) + +* Deprecated passing `default` argument to `#index_name_exists?`. + ([Pull Request](https://github.com/rails/rails/pull/26930)) + +### Notable changes + +* Change Default Primary Keys to BIGINT. + ([Pull Request](https://github.com/rails/rails/pull/26266)) + +* Virtual/generated column support for MySQL 5.7.5+ and MariaDB 5.2.0+. + ([Commit](https://github.com/rails/rails/commit/65bf1c60053e727835e06392d27a2fb49665484c)) + +* Added support for limits in batch processing. + ([Commit](https://github.com/rails/rails/commit/451437c6f57e66cc7586ec966e530493927098c7)) + +* Transactional tests now wrap all Active Record connections in database + transactions. + ([Pull Request](https://github.com/rails/rails/pull/28726)) + +* Skipped comments in the output of `mysqldump` command by default. + ([Pull Request](https://github.com/rails/rails/pull/23301)) + +* Fixed `ActiveRecord::Relation#count` to use Ruby's `Enumerable#count` for counting + records when a block is passed as argument instead of silently ignoring the + passed block. + ([Pull Request](https://github.com/rails/rails/pull/24203)) + +* Pass `"-v ON_ERROR_STOP=1"` flag with `psql` command to not suppress SQL errors. + ([Pull Request](https://github.com/rails/rails/pull/24773)) + +* Add `ActiveRecord::Base.connection_pool.stat`. + ([Pull Request](https://github.com/rails/rails/pull/26988)) + +* Inheriting directly from `ActiveRecord::Migration` raises an error. + Specify the Rails version for which the migration was written for. + ([Commit](https://github.com/rails/rails/commit/249f71a22ab21c03915da5606a063d321f04d4d3)) + +* An error is raised when `through` association has ambiguous reflection name. + ([Commit](https://github.com/rails/rails/commit/0944182ad7ed70d99b078b22426cbf844edd3f61)) + +Active Model +------------ + +Please refer to the [Changelog][active-model] for detailed changes. + +### Removals + +* Removed deprecated methods in `ActiveModel::Errors`. + ([commit](https://github.com/rails/rails/commit/9de6457ab0767ebab7f2c8bc583420fda072e2bd)) + +* Removed deprecated `:tokenizer` option in the length validator. + ([commit](https://github.com/rails/rails/commit/6a78e0ecd6122a6b1be9a95e6c4e21e10e429513)) + +* Remove deprecated behavior that halts callbacks when the return value is false. + ([commit](https://github.com/rails/rails/commit/3a25cdca3e0d29ee2040931d0cb6c275d612dffe)) + +### Notable changes + +* The original string assigned to a model attribute is no longer incorrectly + frozen. + ([Pull Request](https://github.com/rails/rails/pull/28729)) + +Active Job +----------- + +Please refer to the [Changelog][active-job] for detailed changes. + +### Removals + +* Removed deprecated support to passing the adapter class to `.queue_adapter`. + ([commit](https://github.com/rails/rails/commit/d1fc0a5eb286600abf8505516897b96c2f1ef3f6)) + +* Removed deprecated `#original_exception` in `ActiveJob::DeserializationError`. + ([commit](https://github.com/rails/rails/commit/d861a1fcf8401a173876489d8cee1ede1cecde3b)) + +### Notable changes + +* Added declarative exception handling via `ActiveJob::Base.retry_on` and `ActiveJob::Base.discard_on`. + ([Pull Request](https://github.com/rails/rails/pull/25991)) + +* Yield the job instance so you have access to things like `job.arguments` on + the custom logic after retries fail. + ([commit](https://github.com/rails/rails/commit/a1e4c197cb12fef66530a2edfaeda75566088d1f)) + +Active Support +-------------- + +Please refer to the [Changelog][active-support] for detailed changes. + +### Removals + +* Removed the `ActiveSupport::Concurrency::Latch` class. + ([Commit](https://github.com/rails/rails/commit/0d7bd2031b4054fbdeab0a00dd58b1b08fb7fea6)) + +* Removed `halt_callback_chains_on_return_false`. + ([Commit](https://github.com/rails/rails/commit/4e63ce53fc25c3bc15c5ebf54bab54fa847ee02a)) + +* Removed deprecated behavior that halts callbacks when the return is false. + ([Commit](https://github.com/rails/rails/commit/3a25cdca3e0d29ee2040931d0cb6c275d612dffe)) + +### Deprecations + +* The top level `HashWithIndifferentAccess` class has been softly deprecated + in favor of the `ActiveSupport::HashWithIndifferentAccess` one. + ([Pull Request](https://github.com/rails/rails/pull/28157)) + +* Deprecated passing string to `:if` and `:unless` conditional options on `set_callback` and `skip_callback`. + ([Commit](https://github.com/rails/rails/commit/0952552)) + +### Notable changes + +* Fixed duration parsing and traveling to make it consistent across DST changes. + ([Commit](https://github.com/rails/rails/commit/8931916f4a1c1d8e70c06063ba63928c5c7eab1e), + [Pull Request](https://github.com/rails/rails/pull/26597)) + +* Updated Unicode to version 9.0.0. + ([Pull Request](https://github.com/rails/rails/pull/27822)) + +* Add Duration#before and #after as aliases for #ago and #since. + ([Pull Request](https://github.com/rails/rails/pull/27721)) + +* Added `Module#delegate_missing_to` to delegate method calls not + defined for the current object to a proxy object. + ([Pull Request](https://github.com/rails/rails/pull/23930)) + +* Added `Date#all_day` which returns a range representing the whole day + of the current date & time. + ([Pull Request](https://github.com/rails/rails/pull/24930)) + +* Introduced the `assert_changes` and `assert_no_changes` methods for tests. + ([Pull Request](https://github.com/rails/rails/pull/25393)) + +* The `travel` and `travel_to` methods now raise on nested calls. + ([Pull Request](https://github.com/rails/rails/pull/24890)) + +* Update `DateTime#change` to support usec and nsec. + ([Pull Request](https://github.com/rails/rails/pull/28242)) + +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. + +[railties]: https://github.com/rails/rails/blob/5-1-stable/railties/CHANGELOG.md +[action-pack]: https://github.com/rails/rails/blob/5-1-stable/actionpack/CHANGELOG.md +[action-view]: https://github.com/rails/rails/blob/5-1-stable/actionview/CHANGELOG.md +[action-mailer]: https://github.com/rails/rails/blob/5-1-stable/actionmailer/CHANGELOG.md +[action-cable]: https://github.com/rails/rails/blob/5-1-stable/actioncable/CHANGELOG.md +[active-record]: https://github.com/rails/rails/blob/5-1-stable/activerecord/CHANGELOG.md +[active-model]: https://github.com/rails/rails/blob/5-1-stable/activemodel/CHANGELOG.md +[active-support]: https://github.com/rails/rails/blob/5-1-stable/activesupport/CHANGELOG.md +[active-job]: https://github.com/rails/rails/blob/5-1-stable/activejob/CHANGELOG.md diff --git a/guides/source/5_2_release_notes.md b/guides/source/5_2_release_notes.md new file mode 100644 index 0000000000..7b5c4b87e3 --- /dev/null +++ b/guides/source/5_2_release_notes.md @@ -0,0 +1,226 @@ +**DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON http://guides.rubyonrails.org.** + +Ruby on Rails 5.2 Release Notes +=============================== + +Highlights in Rails 5.2: + +* Active Storage +* Redis Cache Store +* HTTP/2 Early hints support +* Credentials +* Default Content Security Policy + +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/5-2-stable) in the main Rails +repository on GitHub. + +-------------------------------------------------------------------------------- + +Upgrading to Rails 5.2 +---------------------- + +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 5.1 in case you +haven't and make sure your application still runs as expected before attempting +an update to Rails 5.2. + + +Major Features +-------------- + +### Active Storage + +[README](https://github.com/rails/rails/blob/d3893ec38ec61282c2598b01a298124356d6b35a/activestorage/README.md) + +### Redis Cache Store + +[Pull Request](https://github.com/rails/rails/pull/31134) + + +### HTTP/2 Early hints support + +[Pull Request](https://github.com/rails/rails/pull/30744) + + +### Credentials + +[Pull Request](https://github.com/rails/rails/pull/30067) + + +### Default Content Security Policy + +[Pull Request](https://github.com/rails/rails/pull/31162) + +Incompatibilities +----------------- + +ToDo + +Railties +-------- + +Please refer to the [Changelog][railties] for detailed changes. + +### Deprecations + +* Deprecate `capify!` method in generators and templates. + ([Pull Request](https://github.com/rails/rails/pull/29493)) + +* Deprecated passing the environment's name as a regular argument to the + `rails dbconsole` and `rails console` commands. + ([Pull Request](https://github.com/rails/rails/pull/29358)) + +* Deprecated using subclass of `Rails::Application` to start the Rails server. + ([Pull Request](https://github.com/rails/rails/pull/30127)) + +* Deprecated `after_bundle` callback in Rails plugin templates. + ([Pull Request](https://github.com/rails/rails/pull/29446)) + +### Notable changes + +ToDo + +Action Cable +----------- + +Please refer to the [Changelog][action-cable] for detailed changes. + +### Removals + +* Removed deprecated evented redis adapter. + ([Commit](https://github.com/rails/rails/commit/48766e32d31)) + +### Notable changes + +* Added support for `host`, `port`, `db` and `password` options in cable.yml + ([Pull Request](https://github.com/rails/rails/pull/29528)) + +* Added support for compatibility with redis-rb gem for 4.0 version. + ([Pull Request](https://github.com/rails/rails/pull/30748)) + +Action Pack +----------- + +Please refer to the [Changelog][action-pack] for detailed changes. + +### Removals + +* Removed deprecated `ActionController::ParamsParser::ParseError`. + ([Commit](https://github.com/rails/rails/commit/e16c765ac6d)) + +### Deprecations + +* Deprecated `#success?`, `#missing?` and `#error?` aliases of + `ActionDispatch::TestResponse`. + ([Pull Request](https://github.com/rails/rails/pull/30104)) + +### Notable changes + +ToDo + +Action View +------------- + +Please refer to the [Changelog][action-view] for detailed changes. + +### Removals + +* Removed deprecated Erubis ERB handler. + ([Commit](https://github.com/rails/rails/commit/7de7f12fd14)) + +### Deprecations + +* Deprecated `image_alt` helper which used to add default alt text to + the images generated by `image_tag`. + ([Pull Request](https://github.com/rails/rails/pull/30213)) + +### Notable changes + +ToDo + +Action Mailer +------------- + +Please refer to the [Changelog][action-mailer] for detailed changes. + +### Notable changes + +ToDo + +Active Record +------------- + +Please refer to the [Changelog][active-record] for detailed changes. + +ToDo + +### Deprecations + +ToDo + +### Notable changes + +ToDo + +Active Model +------------ + +Please refer to the [Changelog][active-model] for detailed changes. + +### Removals + +ToDo + +### Notable changes + +ToDo + +Active Support +-------------- + +Please refer to the [Changelog][active-support] for detailed changes. + +### Removals + +ToDo + +### Deprecations + +ToDo + +### Notable changes + +ToDo + +Active Job +----------- + +Please refer to the [Changelog][active-job] for detailed changes. + +### Removals + +ToDo + +### Notable changes + +ToDo + +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. + +[railties]: https://github.com/rails/rails/blob/5-2-stable/railties/CHANGELOG.md +[action-pack]: https://github.com/rails/rails/blob/5-2-stable/actionpack/CHANGELOG.md +[action-view]: https://github.com/rails/rails/blob/5-2-stable/actionview/CHANGELOG.md +[action-mailer]: https://github.com/rails/rails/blob/5-2-stable/actionmailer/CHANGELOG.md +[action-cable]: https://github.com/rails/rails/blob/5-2-stable/actioncable/CHANGELOG.md +[active-record]: https://github.com/rails/rails/blob/5-2-stable/activerecord/CHANGELOG.md +[active-model]: https://github.com/rails/rails/blob/5-2-stable/activemodel/CHANGELOG.md +[active-support]: https://github.com/rails/rails/blob/5-2-stable/activesupport/CHANGELOG.md +[active-job]: https://github.com/rails/rails/blob/5-2-stable/activejob/CHANGELOG.md diff --git a/guides/source/_welcome.html.erb b/guides/source/_welcome.html.erb index 67f5f1cdd5..6959f992aa 100644 --- a/guides/source/_welcome.html.erb +++ b/guides/source/_welcome.html.erb @@ -1,8 +1,8 @@ -<h2>Ruby on Rails Guides (<%= @edge ? @version[0, 7] : @version %>)</h2> +<h2>Ruby on Rails Guides (<%= @edge ? @edge[0, 7] : @version %>)</h2> <% if @edge %> <p> - These are <b>Edge Guides</b>, based on the current <a href="https://github.com/rails/rails/tree/<%= @version %>">master</a> branch. + These are <b>Edge Guides</b>, based on <a href="https://github.com/rails/rails/tree/<%= @edge %>">master@<%= @edge[0, 7] %></a>. </p> <p> If you are looking for the ones for the stable version, please check @@ -10,15 +10,17 @@ </p> <% else %> <p> - These are the new guides for Rails 5.0 based on <a href="https://github.com/rails/rails/tree/<%= @version %>"><%= @version %></a>. + These are the new guides for Rails 5.1 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 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>. +<a href="http://guides.rubyonrails.org/v5.1/">Rails 5.1</a>, +<a href="http://guides.rubyonrails.org/v5.0/">Rails 5.0</a>, +<a href="http://guides.rubyonrails.org/v4.2/">Rails 4.2</a>, +<a href="http://guides.rubyonrails.org/v4.1/">Rails 4.1</a>, +<a href="http://guides.rubyonrails.org/v4.0/">Rails 4.0</a>, +<a href="http://guides.rubyonrails.org/v3.2/">Rails 3.2</a>, and +<a href="http://guides.rubyonrails.org/v2.3/">Rails 2.3</a>. </p> diff --git a/guides/source/action_cable_overview.md b/guides/source/action_cable_overview.md new file mode 100644 index 0000000000..c250db2e0c --- /dev/null +++ b/guides/source/action_cable_overview.md @@ -0,0 +1,692 @@ +**DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON http://guides.rubyonrails.org.** + +Action Cable Overview +===================== + +In this guide, you will learn how Action Cable works and how to use WebSockets to +incorporate real-time features into your Rails application. + +After reading this guide, you will know: + +* What Action Cable is and its integration backend and frontend +* How to setup Action Cable +* How to setup channels +* Deployment and Architecture setup for running Action Cable + +-------------------------------------------------------------------------------- + +Introduction +------------ + +Action Cable seamlessly integrates +[WebSockets](https://en.wikipedia.org/wiki/WebSocket) with the rest of your +Rails application. It allows for real-time features to be written in Ruby in the +same style and form as the rest of your Rails application, while still being +performant and scalable. It's a full-stack offering that provides both a +client-side JavaScript framework and a server-side Ruby framework. You have +access to your full domain model written with Active Record or your ORM of +choice. + +What is Pub/Sub +--------------- + +[Pub/Sub](https://en.wikipedia.org/wiki/Publish%E2%80%93subscribe_pattern), or +Publish-Subscribe, refers to a message queue paradigm whereby senders of +information (publishers), send data to an abstract class of recipients +(subscribers), without specifying individual recipients. Action Cable uses this +approach to communicate between the server and many clients. + +## Server-Side Components + +### Connections + +*Connections* form the foundation of the client-server relationship. For every +WebSocket accepted by the server, a connection object is instantiated. This +object becomes the parent of all the *channel subscriptions* that are created +from there on. The connection itself does not deal with any specific application +logic beyond authentication and authorization. The client of a WebSocket +connection is called the connection *consumer*. An individual user will create +one consumer-connection pair per browser tab, window, or device they have open. + +Connections are instances of `ApplicationCable::Connection`. In this class, you +authorize the incoming connection, and proceed to establish it if the user can +be identified. + +#### Connection Setup + +```ruby +# app/channels/application_cable/connection.rb +module ApplicationCable + class Connection < ActionCable::Connection::Base + identified_by :current_user + + def connect + self.current_user = find_verified_user + end + + private + def find_verified_user + if verified_user = User.find_by(id: cookies.encrypted[:user_id]) + verified_user + else + reject_unauthorized_connection + end + end + end +end +``` + +Here `identified_by` is a connection identifier that can be used to find the +specific connection later. Note that anything marked as an identifier will automatically +create a delegate by the same name on any channel instances created off the connection. + +This example relies on the fact that you will already have handled authentication of the user +somewhere else in your application, and that a successful authentication sets a signed +cookie with the user ID. + +The cookie is then automatically sent to the connection instance when a new connection +is attempted, and you use that to set the `current_user`. By identifying the connection +by this same current user, you're also ensuring that you can later retrieve all open +connections by a given user (and potentially disconnect them all if the user is deleted +or unauthorized). + +### Channels + +A *channel* encapsulates a logical unit of work, similar to what a controller does in a +regular MVC setup. By default, Rails creates a parent `ApplicationCable::Channel` class +for encapsulating shared logic between your channels. + +#### Parent Channel Setup + +```ruby +# app/channels/application_cable/channel.rb +module ApplicationCable + class Channel < ActionCable::Channel::Base + end +end +``` + +Then you would create your own channel classes. For example, you could have a +`ChatChannel` and an `AppearanceChannel`: + +```ruby +# app/channels/chat_channel.rb +class ChatChannel < ApplicationCable::Channel +end + +# app/channels/appearance_channel.rb +class AppearanceChannel < ApplicationCable::Channel +end +``` + +A consumer could then be subscribed to either or both of these channels. + +#### Subscriptions + +Consumers subscribe to channels, acting as *subscribers*. Their connection is +called a *subscription*. Produced messages are then routed to these channel +subscriptions based on an identifier sent by the cable consumer. + +```ruby +# app/channels/chat_channel.rb +class ChatChannel < ApplicationCable::Channel + # Called when the consumer has successfully + # become a subscriber to this channel. + def subscribed + end +end +``` + +## Client-Side Components + +### Connections + +Consumers require an instance of the connection on their side. This can be +established using the following JavaScript, which is generated by default by Rails: + +#### Connect Consumer + +```js +// app/assets/javascripts/cable.js +//= require action_cable +//= require_self +//= require_tree ./channels + +(function() { + this.App || (this.App = {}); + + App.cable = ActionCable.createConsumer(); +}).call(this); +``` + +This will ready a consumer that'll connect against `/cable` on your server by default. +The connection won't be established until you've also specified at least one subscription +you're interested in having. + +#### Subscriber + +A consumer becomes a subscriber by creating a subscription to a given channel: + +```coffeescript +# app/assets/javascripts/cable/subscriptions/chat.coffee +App.cable.subscriptions.create { channel: "ChatChannel", room: "Best Room" } + +# app/assets/javascripts/cable/subscriptions/appearance.coffee +App.cable.subscriptions.create { channel: "AppearanceChannel" } +``` + +While this creates the subscription, the functionality needed to respond to +received data will be described later on. + +A consumer can act as a subscriber to a given channel any number of times. For +example, a consumer could subscribe to multiple chat rooms at the same time: + +```coffeescript +App.cable.subscriptions.create { channel: "ChatChannel", room: "1st Room" } +App.cable.subscriptions.create { channel: "ChatChannel", room: "2nd Room" } +``` + +## Client-Server Interactions + +### Streams + +*Streams* provide the mechanism by which channels route published content +(broadcasts) to their subscribers. + +```ruby +# app/channels/chat_channel.rb +class ChatChannel < ApplicationCable::Channel + def subscribed + stream_from "chat_#{params[:room]}" + end +end +``` + +If you have a stream that is related to a model, then the broadcasting used +can be generated from the model and channel. The following example would +subscribe to a broadcasting like `comments:Z2lkOi8vVGVzdEFwcC9Qb3N0LzE` + +```ruby +class CommentsChannel < ApplicationCable::Channel + def subscribed + post = Post.find(params[:id]) + stream_for post + end +end +``` + +You can then broadcast to this channel like this: + +```ruby +CommentsChannel.broadcast_to(@post, @comment) +``` + +### Broadcasting + +A *broadcasting* is a pub/sub link where anything transmitted by a publisher +is routed directly to the channel subscribers who are streaming that named +broadcasting. Each channel can be streaming zero or more broadcastings. + +Broadcastings are purely an online queue and time-dependent. If a consumer is +not streaming (subscribed to a given channel), they'll not get the broadcast +should they connect later. + +Broadcasts are called elsewhere in your Rails application: + +```ruby +WebNotificationsChannel.broadcast_to( + current_user, + title: 'New things!', + body: 'All the news fit to print' +) +``` + +The `WebNotificationsChannel.broadcast_to` call places a message in the current +subscription adapter (by default `redis` for production and `async` for development and +test environments)'s pubsub queue under a separate broadcasting name for each user. +For a user with an ID of 1, the broadcasting name would be `web_notifications:1`. + +The channel has been instructed to stream everything that arrives at +`web_notifications:1` directly to the client by invoking the `received` +callback. + +### Subscriptions + +When a consumer is subscribed to a channel, they act as a subscriber. This +connection is called a subscription. Incoming messages are then routed to +these channel subscriptions based on an identifier sent by the cable consumer. + +```coffeescript +# app/assets/javascripts/cable/subscriptions/chat.coffee +# Assumes you've already requested the right to send web notifications +App.cable.subscriptions.create { channel: "ChatChannel", room: "Best Room" }, + received: (data) -> + @appendLine(data) + + appendLine: (data) -> + html = @createLine(data) + $("[data-chat-room='Best Room']").append(html) + + createLine: (data) -> + """ + <article class="chat-line"> + <span class="speaker">#{data["sent_by"]}</span> + <span class="body">#{data["body"]}</span> + </article> + """ +``` + +### Passing Parameters to Channels + +You can pass parameters from the client side to the server side when creating a +subscription. For example: + +```ruby +# app/channels/chat_channel.rb +class ChatChannel < ApplicationCable::Channel + def subscribed + stream_from "chat_#{params[:room]}" + end +end +``` + +An object passed as the first argument to `subscriptions.create` becomes the +params hash in the cable channel. The keyword `channel` is required: + +```coffeescript +# app/assets/javascripts/cable/subscriptions/chat.coffee +App.cable.subscriptions.create { channel: "ChatChannel", room: "Best Room" }, + received: (data) -> + @appendLine(data) + + appendLine: (data) -> + html = @createLine(data) + $("[data-chat-room='Best Room']").append(html) + + createLine: (data) -> + """ + <article class="chat-line"> + <span class="speaker">#{data["sent_by"]}</span> + <span class="body">#{data["body"]}</span> + </article> + """ +``` + +```ruby +# Somewhere in your app this is called, perhaps +# from a NewCommentJob. +ActionCable.server.broadcast( + "chat_#{room}", + sent_by: 'Paul', + body: 'This is a cool chat app.' +) +``` + +### Rebroadcasting a Message + +A common use case is to *rebroadcast* a message sent by one client to any +other connected clients. + +```ruby +# app/channels/chat_channel.rb +class ChatChannel < ApplicationCable::Channel + def subscribed + stream_from "chat_#{params[:room]}" + end + + def receive(data) + ActionCable.server.broadcast("chat_#{params[:room]}", data) + end +end +``` + +```coffeescript +# app/assets/javascripts/cable/subscriptions/chat.coffee +App.chatChannel = App.cable.subscriptions.create { channel: "ChatChannel", room: "Best Room" }, + received: (data) -> + # data => { sent_by: "Paul", body: "This is a cool chat app." } + +App.chatChannel.send({ sent_by: "Paul", body: "This is a cool chat app." }) +``` + +The rebroadcast will be received by all connected clients, _including_ the +client that sent the message. Note that params are the same as they were when +you subscribed to the channel. + +## Full-Stack Examples + +The following setup steps are common to both examples: + + 1. [Setup your connection](#connection-setup). + 2. [Setup your parent channel](#parent-channel-setup). + 3. [Connect your consumer](#connect-consumer). + +### Example 1: User Appearances + +Here's a simple example of a channel that tracks whether a user is online or not +and what page they're on. (This is useful for creating presence features like showing +a green dot next to a user name if they're online). + +Create the server-side appearance channel: + +```ruby +# app/channels/appearance_channel.rb +class AppearanceChannel < ApplicationCable::Channel + def subscribed + current_user.appear + end + + def unsubscribed + current_user.disappear + end + + def appear(data) + current_user.appear(on: data['appearing_on']) + end + + def away + current_user.away + end +end +``` + +When a subscription is initiated the `subscribed` callback gets fired and we +take that opportunity to say "the current user has indeed appeared". That +appear/disappear API could be backed by Redis, a database, or whatever else. + +Create the client-side appearance channel subscription: + +```coffeescript +# app/assets/javascripts/cable/subscriptions/appearance.coffee +App.cable.subscriptions.create "AppearanceChannel", + # Called when the subscription is ready for use on the server. + connected: -> + @install() + @appear() + + # Called when the WebSocket connection is closed. + disconnected: -> + @uninstall() + + # Called when the subscription is rejected by the server. + rejected: -> + @uninstall() + + appear: -> + # Calls `AppearanceChannel#appear(data)` on the server. + @perform("appear", appearing_on: $("main").data("appearing-on")) + + away: -> + # Calls `AppearanceChannel#away` on the server. + @perform("away") + + + buttonSelector = "[data-behavior~=appear_away]" + + install: -> + $(document).on "turbolinks:load.appearance", => + @appear() + + $(document).on "click.appearance", buttonSelector, => + @away() + false + + $(buttonSelector).show() + + uninstall: -> + $(document).off(".appearance") + $(buttonSelector).hide() +``` + +##### Client-Server Interaction + +1. **Client** connects to the **Server** via `App.cable = +ActionCable.createConsumer("ws://cable.example.com")`. (`cable.js`). The +**Server** identifies this connection by `current_user`. + +2. **Client** subscribes to the appearance channel via +`App.cable.subscriptions.create(channel: "AppearanceChannel")`. (`appearance.coffee`) + +3. **Server** recognizes a new subscription has been initiated for the +appearance channel and runs its `subscribed` callback, calling the `appear` +method on `current_user`. (`appearance_channel.rb`) + +4. **Client** recognizes that a subscription has been established and calls +`connected` (`appearance.coffee`) which in turn calls `@install` and `@appear`. +`@appear` calls `AppearanceChannel#appear(data)` on the server, and supplies a +data hash of `{ appearing_on: $("main").data("appearing-on") }`. This is +possible because the server-side channel instance automatically exposes all +public methods declared on the class (minus the callbacks), so that these can be +reached as remote procedure calls via a subscription's `perform` method. + +5. **Server** receives the request for the `appear` action on the appearance +channel for the connection identified by `current_user` +(`appearance_channel.rb`). **Server** retrieves the data with the +`:appearing_on` key from the data hash and sets it as the value for the `:on` +key being passed to `current_user.appear`. + +### Example 2: Receiving New Web Notifications + +The appearance example was all about exposing server functionality to +client-side invocation over the WebSocket connection. But the great thing +about WebSockets is that it's a two-way street. So now let's show an example +where the server invokes an action on the client. + +This is a web notification channel that allows you to trigger client-side +web notifications when you broadcast to the right streams: + +Create the server-side web notifications channel: + +```ruby +# app/channels/web_notifications_channel.rb +class WebNotificationsChannel < ApplicationCable::Channel + def subscribed + stream_for current_user + end +end +``` + +Create the client-side web notifications channel subscription: + +```coffeescript +# app/assets/javascripts/cable/subscriptions/web_notifications.coffee +# Client-side which assumes you've already requested +# the right to send web notifications. +App.cable.subscriptions.create "WebNotificationsChannel", + received: (data) -> + new Notification data["title"], body: data["body"] +``` + +Broadcast content to a web notification channel instance from elsewhere in your +application: + +```ruby +# Somewhere in your app this is called, perhaps from a NewCommentJob +WebNotificationsChannel.broadcast_to( + current_user, + title: 'New things!', + body: 'All the news fit to print' +) +``` + +The `WebNotificationsChannel.broadcast_to` call places a message in the current +subscription adapter's pubsub queue under a separate broadcasting name for each +user. For a user with an ID of 1, the broadcasting name would be +`web_notifications:1`. + +The channel has been instructed to stream everything that arrives at +`web_notifications:1` directly to the client by invoking the `received` +callback. The data passed as argument is the hash sent as the second parameter +to the server-side broadcast call, JSON encoded for the trip across the wire +and unpacked for the data argument arriving as `received`. + +### More Complete Examples + +See the [rails/actioncable-examples](https://github.com/rails/actioncable-examples) +repository for a full example of how to setup Action Cable in a Rails app and adding channels. + +## Configuration + +Action Cable has two required configurations: a subscription adapter and allowed request origins. + +### Subscription Adapter + +By default, Action Cable looks for a configuration file in `config/cable.yml`. +The file must specify an adapter for each Rails environment. See the +[Dependencies](#dependencies) section for additional information on adapters. + +```yaml +development: + adapter: async + +test: + adapter: async + +production: + adapter: redis + url: redis://10.10.3.153:6381 + channel_prefix: appname_production +``` +#### Adapter Configuration + +Below is a list of the subscription adapters available for end users. + +##### Async Adapter + +The async adapter is intended for development/testing and should not be used in production. + +##### Redis Adapter + +The Redis adapter requires users to provide a URL pointing to the Redis server. +Additionally, a `channel_prefix` may be provided to avoid channel name collisions +when using the same Redis server for multiple applications. See the [Redis PubSub documentation](https://redis.io/topics/pubsub#database-amp-scoping) for more details. + +##### PostgreSQL Adapter + +The PostgreSQL adapter uses Active Record's connection pool, and thus the +application's `config/database.yml` database configuration, for its connection. +This may change in the future. [#27214](https://github.com/rails/rails/issues/27214) + +### Allowed Request Origins + +Action Cable will only accept requests from specified origins, which are +passed to the server config as an array. The origins can be instances of +strings or regular expressions, against which a check for the match will be performed. + +```ruby +config.action_cable.allowed_request_origins = ['http://rubyonrails.com', %r{http://ruby.*}] +``` + +To disable and allow requests from any origin: + +```ruby +config.action_cable.disable_request_forgery_protection = true +``` + +By default, Action Cable allows all requests from localhost:3000 when running +in the development environment. + +### Consumer Configuration + +To configure the URL, add a call to `action_cable_meta_tag` in your HTML layout +HEAD. This uses a URL or path typically set via `config.action_cable.url` in the +environment configuration files. + +### Other Configurations + +The other common option to configure is the log tags applied to the +per-connection logger. Here's an example that uses +the user account id if available, else "no-account" while tagging: + +```ruby +config.action_cable.log_tags = [ + -> request { request.env['user_account_id'] || "no-account" }, + :action_cable, + -> request { request.uuid } +] +``` + +For a full list of all configuration options, see the +`ActionCable::Server::Configuration` class. + +Also, note that your server must provide at least the same number of database +connections as you have workers. The default worker pool size is set to 4, so +that means you have to make at least that available. You can change that in +`config/database.yml` through the `pool` attribute. + +## Running Standalone Cable Servers + +### In App + +Action Cable can run alongside your Rails application. For example, to +listen for WebSocket requests on `/websocket`, specify that path to +`config.action_cable.mount_path`: + +```ruby +# config/application.rb +class Application < Rails::Application + config.action_cable.mount_path = '/websocket' +end +``` + +You can use `App.cable = ActionCable.createConsumer()` to connect to the cable +server if `action_cable_meta_tag` is invoked in the layout. A custom path is +specified as first argument to `createConsumer` (e.g. `App.cable = +ActionCable.createConsumer("/websocket")`). + +For every instance of your server you create and for every worker your server +spawns, you will also have a new instance of Action Cable, but the use of Redis +keeps messages synced across connections. + +### Standalone + +The cable servers can be separated from your normal application server. It's +still a Rack application, but it is its own Rack application. The recommended +basic setup is as follows: + +```ruby +# cable/config.ru +require_relative '../config/environment' +Rails.application.eager_load! + +run ActionCable.server +``` + +Then you start the server using a binstub in `bin/cable` ala: + +``` +#!/bin/bash +bundle exec puma -p 28080 cable/config.ru +``` + +The above will start a cable server on port 28080. + +### Notes + +The WebSocket server doesn't have access to the session, but it has +access to the cookies. This can be used when you need to handle +authentication. You can see one way of doing that with Devise in this [article](http://www.rubytutorial.io/actioncable-devise-authentication). + +## Dependencies + +Action Cable provides a subscription adapter interface to process its +pubsub internals. By default, asynchronous, inline, PostgreSQL, and Redis +adapters are included. The default adapter +in new Rails applications is the asynchronous (`async`) adapter. + +The Ruby side of things is built on top of [websocket-driver](https://github.com/faye/websocket-driver-ruby), +[nio4r](https://github.com/celluloid/nio4r), and [concurrent-ruby](https://github.com/ruby-concurrency/concurrent-ruby). + +## Deployment + +Action Cable is powered by a combination of WebSockets and threads. Both the +framework plumbing and user-specified channel work are handled internally by +utilizing Ruby's native thread support. This means you can use all your regular +Rails models with no problem, as long as you haven't committed any thread-safety sins. + +The Action Cable server implements the Rack socket hijacking API, +thereby allowing the use of a multithreaded pattern for managing connections +internally, irrespective of whether the application server is multi-threaded or not. + +Accordingly, Action Cable works with popular servers like Unicorn, Puma, and +Passenger. diff --git a/guides/source/action_controller_overview.md b/guides/source/action_controller_overview.md index 8c1551f4a1..6ecfb57db3 100644 --- a/guides/source/action_controller_overview.md +++ b/guides/source/action_controller_overview.md @@ -21,9 +21,9 @@ After reading this guide, you will know: What Does a Controller Do? -------------------------- -Action Controller is the C in MVC. After routing has determined which controller to use for a request, the controller is responsible for making sense of the request and producing the appropriate output. Luckily, Action Controller does most of the groundwork for you and uses smart conventions to make this as straightforward as possible. +Action Controller is the C in [MVC](https://en.wikipedia.org/wiki/Model%E2%80%93view%E2%80%93controller). After the router has determined which controller to use for a request, the controller is responsible for making sense of the request, and producing the appropriate output. Luckily, Action Controller does most of the groundwork for you and uses smart conventions to make this as straightforward as possible. -For most conventional [RESTful](http://en.wikipedia.org/wiki/Representational_state_transfer) applications, the controller will receive the request (this is invisible to you as the developer), fetch or save data from a model and use a view to create HTML output. If your controller needs to do things a little differently, that's not a problem, this is just the most common way for a controller to work. +For most conventional [RESTful](https://en.wikipedia.org/wiki/Representational_state_transfer) applications, the controller will receive the request (this is invisible to you as the developer), fetch or save data from a model and use a view to create HTML output. If your controller needs to do things a little differently, that's not a problem, this is just the most common way for a controller to work. A controller can thus be thought of as a middleman between models and views. It makes the model data available to the view so it can display that data to the user, and it saves or updates user data to the model. @@ -61,7 +61,7 @@ end The [Layouts & Rendering Guide](layouts_and_rendering.html) explains this in more detail. -`ApplicationController` inherits from `ActionController::Base`, which defines a number of helpful methods. This guide will cover some of these, but if you're curious to see what's in there, you can see all of them in the API documentation or in the source itself. +`ApplicationController` inherits from `ActionController::Base`, which defines a number of helpful methods. This guide will cover some of these, but if you're curious to see what's in there, you can see all of them in the [API documentation](http://api.rubyonrails.org/classes/ActionController.html) or in the source itself. Only public methods are callable as actions. It is a best practice to lower the visibility of methods (with `private` or `protected`) which are not intended to be actions, like auxiliary methods or filters. @@ -145,7 +145,7 @@ So for example, if you are sending this JSON content: Your controller will receive `params[:company]` as `{ "name" => "acme", "address" => "123 Carrot Street" }`. -Also, if you've turned on `config.wrap_parameters` in your initializer or called `wrap_parameters` in your controller, you can safely omit the root element in the JSON parameter. In this case, the parameters will be cloned and wrapped with a key chosen based on your controller's name. So the above JSON POST can be written as: +Also, if you've turned on `config.wrap_parameters` in your initializer or called `wrap_parameters` in your controller, you can safely omit the root element in the JSON parameter. In this case, the parameters will be cloned and wrapped with a key chosen based on your controller's name. So the above JSON request can be written as: ```json { "name": "acme", "address": "123 Carrot Street" } @@ -185,7 +185,9 @@ end These options will be used as a starting point when generating URLs, so it's possible they'll be overridden by the options passed to `url_for` calls. -If you define `default_url_options` in `ApplicationController`, as in the example above, it will be used for all URL generation. The method can also be defined in a specific controller, in which case it only affects URLs generated there. +If you define `default_url_options` in `ApplicationController`, as in the example above, these defaults will be used for all URL generation. The method can also be defined in a specific controller, in which case it only affects URLs generated there. + +In a given request, the method is not actually called for every single generated URL; for performance reasons, the returned hash is cached, there is at most one invocation per request. ### Strong Parameters @@ -197,11 +199,12 @@ practice to help prevent accidentally allowing users to update sensitive model attributes. In addition, parameters can be marked as required and will flow through a -predefined raise/rescue flow to end up as a 400 Bad Request. +predefined raise/rescue flow that will result in a 400 Bad Request being +returned if not all required parameters are passed in. ```ruby class PeopleController < ActionController::Base - # This will raise an ActiveModel::ForbiddenAttributes exception + # This will raise an ActiveModel::ForbiddenAttributesError exception # because it's using mass assignment without an explicit permit # step. def create @@ -211,8 +214,8 @@ class PeopleController < ActionController::Base # 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. + # caught by ActionController::Base and turned into a 400 Bad + # Request error. def update person = current_account.people.find(params[:id]) person.update!(person_params) @@ -255,6 +258,17 @@ scalar values, map the key to an empty array: params.permit(id: []) ``` +Sometimes it is not possible or convenient to declare the valid keys of +a hash parameter or its internal structure. Just map to an empty hash: + +```ruby +params.permit(preferences: {}) +``` + +but be careful because this opens the door to arbitrary input. In this +case, `permit` ensures values in the returned structure are permitted +scalars and filters out anything else. + To whitelist an entire hash of parameters, the `permit!` method can be used: @@ -262,9 +276,10 @@ used: params.require(:log_entry).permit! ``` -This will mark the `:log_entry` parameters hash and any sub-hash of it as -permitted. Extreme care should be taken when using `permit!`, as it -will allow all current and future model attributes to be mass-assigned. +This marks the `:log_entry` parameters hash and any sub-hash of it as +permitted and does not check for permitted scalars, anything is accepted. +Extreme care should be taken when using `permit!`, as it will allow all current +and future model attributes to be mass-assigned. #### Nested Parameters @@ -359,7 +374,7 @@ If your user sessions don't store critical data or don't need to be around for l Read more about session storage in the [Security Guide](security.html). -If you need a different session storage mechanism, you can change it in the `config/initializers/session_store.rb` file: +If you need a different session storage mechanism, you can change it in an initializer: ```ruby # Use the database for sessions instead of the cookie-based default, @@ -368,7 +383,7 @@ If you need a different session storage mechanism, you can change it in the `con # 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`: +Rails sets up a session key (the name of the cookie) when signing the session data. These can also be changed in an initializer: ```ruby # Be sure to restart your server when you modify this file. @@ -382,34 +397,18 @@ You can also pass a `:domain` key and specify the domain name for the cookie: 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/secrets.yml` +Rails sets up (for the CookieStore) a secret key used for signing the session data in `config/credentials.yml.enc`. This can be changed with `bin/rails credentials:edit`. ```ruby -# Be sure to restart your server when you modify this file. - -# Your secret key is used for verifying the integrity of signed cookies. -# If you change this key, all old signed cookies will become invalid! +# aws: +# access_key_id: 123 +# secret_access_key: 345 -# Make sure the secret is at least 30 characters and all random, -# no regular words or you'll be exposed to dictionary attacks. -# 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"] %> +# Used as the base secret for all MessageVerifiers in Rails, including the one protecting cookies. +secret_key_base: 492f... ``` -NOTE: Changing the secret when using the `CookieStore` will invalidate all existing sessions. +NOTE: Changing the secret_key_base when using the `CookieStore` will invalidate all existing sessions. ### Accessing the Session @@ -655,8 +654,8 @@ class UsersController < ApplicationController @users = User.all respond_to do |format| format.html # index.html.erb - format.xml { render xml: @users} - format.json { render json: @users} + format.xml { render xml: @users } + format.json { render json: @users } end end end @@ -667,11 +666,11 @@ You may notice in the above code that we're using `render xml: @users`, not `ren Filters ------- -Filters are methods that are run before, after or "around" a controller action. +Filters are methods that are run "before", "after" or "around" a controller action. Filters are inherited, so if you set a filter on `ApplicationController`, it will be run on every controller in your application. -"Before" filters may halt the request cycle. A common "before" filter is one which requires that a user is logged in for an action to be run. You can define the filter method this way: +"before" filters may halt the request cycle. A common "before" filter is one which requires that a user is logged in for an action to be run. You can define the filter method this way: ```ruby class ApplicationController < ActionController::Base @@ -698,15 +697,18 @@ class LoginsController < ApplicationController end ``` -Now, the `LoginsController`'s `new` and `create` actions will work as before without requiring the user to be logged in. The `:only` option is used to only skip this filter for these actions, and there is also an `:except` option which works the other way. These options can be used when adding filters too, so you can add a filter which only runs for selected actions in the first place. +Now, the `LoginsController`'s `new` and `create` actions will work as before without requiring the user to be logged in. The `:only` option is used to skip this filter only for these actions, and there is also an `:except` option which works the other way. These options can be used when adding filters too, so you can add a filter which only runs for selected actions in the first place. + +NOTE: Calling the same filter multiple times with different options will not work, +since the last filter definition will overwrite the previous ones. ### After Filters and Around Filters In addition to "before" filters, you can also run filters after an action has been executed, or both before and after. -"After" filters are similar to "before" filters, but because the action has already been run they have access to the response data that's about to be sent to the client. Obviously, "after" filters cannot stop the action from running. +"after" filters are similar to "before" filters, but because the action has already been run they have access to the response data that's about to be sent to the client. Obviously, "after" filters cannot stop the action from running. Please note that "after" filters are executed only after a successful action, but not when an exception is raised in the request cycle. -"Around" filters are responsible for running their associated actions by yielding, similar to how Rack middlewares work. +"around" filters are responsible for running their associated actions by yielding, similar to how Rack middlewares work. 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: @@ -736,7 +738,7 @@ You can choose not to yield and build the response yourself, in which case the a While the most common way to use filters is by creating private methods and using *_action to add them, there are two other ways to do the same thing. -The first is to use a block directly with the *\_action methods. The block receives the controller as an argument, and the `require_login` filter from above could be rewritten to use a block: +The first is to use a block directly with the *\_action methods. The block receives the controller as an argument. The `require_login` filter from above could be rewritten to use a block: ```ruby class ApplicationController < ActionController::Base @@ -749,7 +751,7 @@ class ApplicationController < ActionController::Base 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. +Note that the filter in this case uses `send` because the `logged_in?` method is private and the filter does 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 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: @@ -782,9 +784,9 @@ The way this is done is to add a non-guessable token which is only known to your If you generate a form like this: ```erb -<%= form_for @user do |f| %> - <%= f.text_field :username %> - <%= f.text_field :password %> +<%= form_with model: @user, local: true do |form| %> + <%= form.text_field :username %> + <%= form.text_field :password %> <% end %> ``` @@ -808,11 +810,11 @@ The [Security Guide](security.html) has more about this and a lot of other secur The Request and Response Objects -------------------------------- -In every controller there are two accessor methods pointing to the request and the response objects associated with the request cycle that is currently in execution. The `request` method contains an instance of `AbstractRequest` and the `response` method returns a response object representing what is going to be sent back to the client. +In every controller there are two accessor methods pointing to the request and the response objects associated with the request cycle that is currently in execution. The `request` method contains an instance of `ActionDispatch::Request` and the `response` method returns a response object representing what is going to be sent back to the client. ### The `request` Object -The request object contains a lot of useful information about the request coming in from the client. To get a full list of the available methods, refer to the [API documentation](http://api.rubyonrails.org/classes/ActionDispatch/Request.html). Among the properties that you can access on this object are: +The request object contains a lot of useful information about the request coming in from the client. To get a full list of the available methods, refer to the [Rails API documentation](http://api.rubyonrails.org/classes/ActionDispatch/Request.html) and [Rack Documentation](http://www.rubydoc.info/github/rack/rack/Rack/Request). Among the properties that you can access on this object are: | Property of `request` | Purpose | | ----------------------------------------- | -------------------------------------------------------------------------------- | @@ -834,7 +836,7 @@ Rails collects all of the parameters sent along with the request in the `params` ### The `response` Object -The response object is not usually used directly, but is built up during the execution of the action and rendering of the data that is being sent back to the user, but sometimes - like in an after filter - it can be useful to access the response directly. Some of these accessor methods also have setters, allowing you to change their values. +The response object is not usually used directly, but is built up during the execution of the action and rendering of the data that is being sent back to the user, but sometimes - like in an after filter - it can be useful to access the response directly. Some of these accessor methods also have setters, allowing you to change their values. To get a full list of the available methods, refer to the [Rails API documentation](http://api.rubyonrails.org/classes/ActionDispatch/Response.html) and [Rack Documentation](http://www.rubydoc.info/github/rack/rack/Rack/Response). | Property of `response` | Purpose | | ---------------------- | --------------------------------------------------------------------------------------------------- | @@ -993,10 +995,6 @@ 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 @@ -1027,7 +1025,7 @@ 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 +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 @@ -1090,6 +1088,8 @@ You can filter out sensitive request parameters from your log files by appending config.filter_parameters << :password ``` +NOTE: Provided parameters will be filtered out by partial matching regular expression. Rails adds default `:password` in the appropriate initializer (`initializers/filter_parameter_logging.rb`) and cares about typical application parameters `password` and `password_confirmation`. + ### Redirects Filtering Sometimes it's desirable to filter out from log files some sensitive locations your application is redirecting to. @@ -1112,11 +1112,11 @@ Rescue Most likely your application is going to contain bugs or otherwise throw an exception that needs to be handled. For example, if the user follows a link to a resource that no longer exists in the database, Active Record will throw the `ActiveRecord::RecordNotFound` exception. -Rails' default exception handling displays a "500 Server Error" message for all exceptions. If the request was made locally, a nice traceback and some added information gets displayed so you can figure out what went wrong and deal with it. If the request was remote Rails will just display a simple "500 Server Error" message to the user, or a "404 Not Found" if there was a routing error or a record could not be found. Sometimes you might want to customize how these errors are caught and how they're displayed to the user. There are several levels of exception handling available in a Rails application: +Rails default exception handling displays a "500 Server Error" message for all exceptions. If the request was made locally, a nice traceback and some added information gets displayed so you can figure out what went wrong and deal with it. If the request was remote Rails will just display a simple "500 Server Error" message to the user, or a "404 Not Found" if there was a routing error or a record could not be found. Sometimes you might want to customize how these errors are caught and how they're displayed to the user. There are several levels of exception handling available in a Rails application: ### The Default 500 and 404 Templates -By default a production application will render either a 404 or a 500 error message. These messages are contained in static HTML files in the `public` folder, in `404.html` and `500.html` respectively. You can customize these files to add some extra information and layout, but remember that they are static; i.e. you can't use RHTML or layouts in them, just plain HTML. +By default a production application will render either a 404 or a 500 error message, in the development environment all unhandled exceptions are raised. These messages are contained in static HTML files in the public folder, in `404.html` and `500.html` respectively. You can customize these files to add some extra information and style, but remember that they are static HTML; i.e. you can't use ERB, SCSS, CoffeeScript, or layouts for them. ### `rescue_from` @@ -1148,7 +1148,7 @@ class ApplicationController < ActionController::Base def user_not_authorized flash[:error] = "You don't have access to this section." - redirect_to :back + redirect_back(fallback_location: root_path) end end @@ -1170,9 +1170,13 @@ class ClientsController < ApplicationController 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). +WARNING: Using `rescue_from` with `Exception` or `StandardError` would cause serious side-effects as it prevents Rails from handling exceptions properly. As such, it is not recommended to do so unless there is a strong reason. + +NOTE: When running in the production environment, all +`ActiveRecord::RecordNotFound` errors render the 404 error page. Unless you need +a custom behavior you don't need to handle this. -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. +NOTE: Certain exceptions are only rescuable from the `ApplicationController` class, as they are raised before the controller gets initialized and the action gets executed. Force HTTPS protocol -------------------- diff --git a/guides/source/action_mailer_basics.md b/guides/source/action_mailer_basics.md index 73b240ff2c..cb07781d1c 100644 --- a/guides/source/action_mailer_basics.md +++ b/guides/source/action_mailer_basics.md @@ -64,7 +64,7 @@ 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`: +`app/mailers`, just make sure that it inherits from `ActionMailer::Base`: ```ruby class MyMailer < ActionMailer::Base @@ -92,8 +92,8 @@ registered email address: class UserMailer < ApplicationMailer default from: 'notifications@example.com' - def welcome_email(user) - @user = user + def welcome_email + @user = params[:user] @url = 'http://example.com/login' mail(to: @user.email, subject: 'Welcome to My Awesome Site') end @@ -160,8 +160,8 @@ When you call the `mail` method now, Action Mailer will detect the two templates #### Calling the Mailer 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 +view and sending it over 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. @@ -170,13 +170,13 @@ First, let's create a simple `User` scaffold: ```bash $ bin/rails generate scaffold user name email login -$ bin/rake db:migrate +$ bin/rails 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. +call to `UserMailer.with(user: @user).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: @@ -191,7 +191,7 @@ 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_later + UserMailer.with(user: @user).welcome_email.deliver_later format.html { redirect_to(@user, notice: 'User was successfully created.') } format.json { render json: @user, status: :created, location: @user } @@ -204,10 +204,14 @@ class UsersController < ApplicationController end ``` -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). +NOTE: Active Job's default behavior is to execute jobs via the `:async` adapter. So, you can use +`deliver_later` now to send emails asynchronously. +Active Job's default adapter runs jobs with an in-process thread pool. +It's well-suited for the development/test environments, since it doesn't require +any external infrastructure, but it's a poor fit for production since it drops +pending jobs on restart. +If you need a persistent backend, you will need to use an Active Job adapter +that has a persistent backend (Sidekiq, Resque, etc). If you want to send emails right away (from a cronjob for example) just call `deliver_now`: @@ -216,13 +220,18 @@ If you want to send emails right away (from a cronjob for example) just call class SendWeeklySummary def run User.find_each do |user| - UserMailer.weekly_summary(user).deliver_now + UserMailer.with(user: user).weekly_summary.deliver_now end end end ``` -The method `welcome_email` returns a `ActionMailer::MessageDelivery` object which +Any key value pair passed to `with` just becomes the `params` for the mailer +action. So `with(user: @user, account: @user.account)` makes `params[:user]` and +`params[:account]` available in the mailer action. Just like controllers have +params. + +The method `welcome_email` returns an `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 @@ -278,7 +287,7 @@ different, encode your content and pass in the encoded content and encoding in a ```ruby encoded_content = SpecialEncode(File.read('/path/to/filename.jpg')) attachments['filename.jpg'] = { - mime_type: 'application/x-gzip', + mime_type: 'application/gzip', encoding: 'SpecialEncoding', content: encoded_content } @@ -326,8 +335,8 @@ 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 - default to: Proc.new { Admin.pluck(:email) }, +class AdminMailer < ApplicationMailer + default to: -> { Admin.pluck(:email) }, from: 'notification@example.com' def new_registration(user) @@ -344,11 +353,11 @@ The same format can be used to set carbon copy (Cc:) and blind carbon copy 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>"`. +email address in the format `"Full Name" <email>`. ```ruby -def welcome_email(user) - @user = user +def welcome_email + @user = params[:user] email_with_name = %("#{@user.name}" <#{@user.email}>) mail(to: email_with_name, subject: 'Welcome to My Awesome Site') end @@ -368,8 +377,8 @@ To change the default mailer view for your action you do something like: class UserMailer < ApplicationMailer default from: 'notifications@example.com' - def welcome_email(user) - @user = user + def welcome_email + @user = params[:user] @url = 'http://example.com/login' mail(to: @user.email, subject: 'Welcome to My Awesome Site', @@ -390,13 +399,13 @@ templates or even render inline or text without using a template file: class UserMailer < ApplicationMailer default from: 'notifications@example.com' - def welcome_email(user) - @user = user + def welcome_email + @user = params[:user] @url = 'http://example.com/login' mail(to: @user.email, subject: 'Welcome to My Awesome Site') do |format| format.html { render 'another_template' } - format.text { render text: 'Render text' } + format.text { render plain: 'Render text' } end end end @@ -407,6 +416,25 @@ 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. +#### Caching mailer view + +You can perform fragment caching in mailer views like in application views using the `cache` method. + +``` +<% cache do %> + <%= @company.name %> +<% end %> +``` + +And in order to use this feature, you need to configure your application with this: + +``` + config.action_mailer.perform_caching = true +``` + +Fragment caching is also supported in multipart emails. +Read more about caching in the [Rails caching guide](caching_with_rails.html). + ### Action Mailer Layouts Just like controller views, you can also have mailer layouts. The layout name @@ -430,8 +458,8 @@ the format block to specify different layouts for different formats: ```ruby class UserMailer < ApplicationMailer - def welcome_email(user) - mail(to: user.email) do |format| + def welcome_email + mail(to: params[:user].email) do |format| format.html { render layout: 'my_layout' } format.text end @@ -454,7 +482,7 @@ special URL that renders them. In the above example, the preview class for ```ruby class UserMailerPreview < ActionMailer::Preview def welcome_email - UserMailer.welcome_email(User.first) + UserMailer.with(user: User.first).welcome_email end end ``` @@ -503,9 +531,9 @@ You will need to use: By using the full URL, your links will now work in your emails. -#### generating URLs with `url_for` +#### Generating URLs with `url_for` -`url_for` generate full URL by default in templates. +`url_for` generates a full URL by default in templates. If you did not configure the `:host` option globally make sure to pass it to `url_for`. @@ -517,7 +545,7 @@ If you did not configure the `:host` option globally make sure to pass it to action: 'greeting') %> ``` -#### generating URLs with named routes +#### Generating URLs with Named Routes 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 @@ -530,10 +558,32 @@ url helper. <%= user_url(@user, host: 'example.com') %> ``` +NOTE: non-`GET` links require [rails-ujs](https://github.com/rails/rails/blob/master/actionview/app/assets/javascripts) or +[jQuery UJS](https://github.com/rails/jquery-ujs), and won't work in mailer templates. +They will result in normal `GET` requests. + +### Adding images in Action Mailer Views + +Unlike controllers, the mailer instance doesn't have any context about the +incoming request so you'll need to provide the `:asset_host` parameter yourself. + +As the `:asset_host` usually is consistent across the application you can +configure it globally in `config/application.rb`: + +```ruby +config.action_mailer.asset_host = 'http://example.com' +``` + +Now you can display an image inside your email. + +```ruby +<%= image_tag 'image.jpg' %> +``` + ### 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 +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. @@ -549,12 +599,12 @@ mailer action. ```ruby class UserMailer < ApplicationMailer - def welcome_email(user, company) - @user = user + def welcome_email + @user = params[:user] @url = user_url(@user) - delivery_options = { user_name: company.smtp_user, - password: company.smtp_password, - address: company.smtp_host } + delivery_options = { user_name: params[:company].smtp_user, + password: params[:company].smtp_password, + address: params[:company].smtp_host } mail(to: @user.email, subject: "Please see the Terms and Conditions attached", delivery_method_options: delivery_options) @@ -571,9 +621,9 @@ will default to `text/plain` otherwise. ```ruby class UserMailer < ApplicationMailer - def welcome_email(user, email_body) - mail(to: user.email, - body: email_body, + def welcome_email + mail(to: params[:user].email, + body: params[:email_body], content_type: "text/html", subject: "Already rendered!") end @@ -632,24 +682,43 @@ Action Mailer allows for you to specify a `before_action`, `after_action` and * You could use a `before_action` to populate the mail object with defaults, delivery_method_options or insert default headers and attachments. +```ruby +class InvitationsMailer < ApplicationMailer + before_action { @inviter, @invitee = params[:inviter], params[:invitee] } + before_action { @account = params[:inviter].account } + + default to: -> { @invitee.email_address }, + from: -> { common_address(@inviter) }, + reply_to: -> { @inviter.email_address_with_name } + + def account_invitation + mail subject: "#{@inviter.name} invited you to their Basecamp (#{@account.name})" + end + + def project_invitation + @project = params[:project] + @summarizer = ProjectInvitationSummarizer.new(@project.bucket) + + mail subject: "#{@inviter.name.familiar} added you to a project in Basecamp (#{@account.name})" + end +end +``` + * 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 < ApplicationMailer + before_action { @business, @user = params[:business], params[:user] } + after_action :set_delivery_options, :prevent_delivery_to_guests, :set_business_headers - def feedback_message(business, user) - @business = business - @user = user - mail + def feedback_message end - def campaign_message(business, user) - @business = business - @user = user + def campaign_message end private @@ -693,8 +762,8 @@ files (environment.rb, production.rb, etc...) | Configuration | Description | |---------------|-------------| |`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>| -|`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>| +|`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` (will send the password in the clear), `:login` (will send password Base64 encoded) or `:cram_md5` (combines a Challenge/Response mechanism to exchange information and a cryptographic Message Digest 5 algorithm to hash important information)</li><li>`:enable_starttls_auto` - Detects if STARTTLS is enabled in your SMTP server and starts to use it. Defaults to `true`.</li><li>`:openssl_verify_mode` - When using TLS, you can set how OpenSSL checks the certificate. This is really useful if you need to validate a self-signed and/or a wildcard certificate. You can use the name of an OpenSSL verify constant ('none' or 'peer') or directly the constant (`OpenSSL::SSL::VERIFY_NONE` or `OpenSSL::SSL::VERIFY_PEER`).</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`.</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:<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.| @@ -715,7 +784,7 @@ config.action_mailer.delivery_method = :sendmail # Defaults to: # config.action_mailer.sendmail_settings = { # location: '/usr/sbin/sendmail', -# arguments: '-i -t' +# arguments: '-i' # } config.action_mailer.perform_deliveries = true config.action_mailer.raise_delivery_errors = true @@ -738,6 +807,10 @@ config.action_mailer.smtp_settings = { authentication: 'plain', enable_starttls_auto: true } ``` +Note: As of July 15, 2014, Google increased [its security measures](https://support.google.com/accounts/answer/6010255) and now blocks attempts from apps it deems less secure. +You can change your Gmail settings [here](https://www.google.com/settings/security/lesssecureapps) to allow the attempts. If your Gmail account has 2-factor authentication enabled, +then you will need to set an [app password](https://myaccount.google.com/apppasswords) and use that instead of your regular password. Alternatively, you can +use another ESP to send email by replacing 'smtp.gmail.com' above with the address of your provider. Mailer Testing -------------- diff --git a/guides/source/action_view_overview.md b/guides/source/action_view_overview.md index 71f3f8882c..1cba5c6fb6 100644 --- a/guides/source/action_view_overview.md +++ b/guides/source/action_view_overview.md @@ -7,7 +7,7 @@ After reading this guide, you will know: * What Action View is and how to use it with Rails. * How best to use templates, partials, and layouts. -* What helpers are provided by Action View and how to make your own. +* What helpers are provided by Action View. * How to use localized views. -------------------------------------------------------------------------------- @@ -15,7 +15,7 @@ After reading this guide, you will know: What is Action View? -------------------- -Action View and Action Controller are the two major components of Action Pack. In Rails, web requests are handled by Action Pack, which splits the work into a controller part (performing the logic) and a view part (rendering a template). Typically, Action Controller will be concerned with communicating with the database and performing CRUD actions where necessary. Action View is then responsible for compiling the response. +In Rails, web requests are handled by [Action Controller](action_controller_overview.html) and Action View. Typically, Action Controller is concerned with communicating with the database and performing CRUD actions where necessary. Action View is then responsible for compiling the response. Action View templates are written using embedded Ruby in tags mingled with HTML. To avoid cluttering the templates with boilerplate code, a number of helper classes provide common behavior for forms, dates, and strings. It's also easy to add new helpers to your application as it evolves. @@ -147,6 +147,39 @@ xml.rss("version" => "2.0", "xmlns:dc" => "http://purl.org/dc/elements/1.1/") do end ``` +#### Jbuilder +[Jbuilder](https://github.com/rails/jbuilder) is a gem that's +maintained by the Rails team and included in the default Rails `Gemfile`. +It's similar to Builder, but is used to generate JSON, instead of XML. + +If you don't have it, you can add the following to your `Gemfile`: + +```ruby +gem 'jbuilder' +``` + +A Jbuilder object named `json` is automatically made available to templates with +a `.jbuilder` extension. + +Here is a basic example: + +```ruby +json.name("Alex") +json.email("alex@example.com") +``` + +would produce: + +```json +{ + "name": "Alex", + "email": "alex@example.com" +} +``` + +See the [Jbuilder documentation](https://github.com/rails/jbuilder#jbuilder) for +more examples and information. + #### Template Caching By default, Rails will compile each template to a method in order to render it. When you alter a template, Rails will check the file's modification time and recompile it in development mode. @@ -214,19 +247,14 @@ By default `ActionView::Partials::PartialRenderer` has its object in a local var <%= render partial: "product" %> ``` -within product we'll get `@product` in the local variable `product`, as if we had written: +within `_product` partial we'll get `@product` in the local variable `product`, +as if we had written: ```erb <%= render partial: "product", locals: { product: @product } %> ``` -With the `as` option we can specify a different name for the local variable. For example, if we wanted it to be `item` instead of `product` we would do: - -```erb -<%= render partial: "product", as: "item" %> -``` - -The `object` option can be used to directly specify which object is rendered into the partial; useful when the template's object is elsewhere (eg. in a different instance variable or in a local variable). +The `object` option can be used to directly specify which object is rendered into the partial; useful when the template's object is elsewhere (e.g. in a different instance variable or in a local variable). For example, instead of: @@ -240,12 +268,18 @@ we would do: <%= render partial: "product", object: @item %> ``` -The `object` and `as` options can also be used together: +With the `as` option we can specify a different name for the said local variable. For example, if we wanted it to be `item` instead of `product` we would do: ```erb <%= render partial: "product", object: @item, as: "item" %> ``` +This is equivalent to + +```erb +<%= render partial: "product", locals: { item: @item } %> +``` + #### Rendering Collections 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. @@ -317,26 +351,6 @@ The `box` layout simply wraps the `_article` partial in a `div`: </div> ``` -The `_article` partial wraps the article's `body` in a `div` with the `id` of the article using the `div_for` helper: - -**articles/_article.html.erb** - -```html+erb -<%= div_for(article) do %> - <p><%= article.body %></p> -<% end %> -``` - -this would output the following: - -```html -<div class='box'> - <div id='article_1'> - <p>Partial Layouts are cool!</p> - </div> -</div> -``` - 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 `_article` partial, we could do this instead: @@ -345,9 +359,9 @@ You can also render a block of code within a partial layout instead of calling ` ```html+erb <% render(layout: 'box', locals: { article: @article }) do %> - <%= div_for(article) do %> + <div> <p><%= article.body %></p> - <% end %> + </div> <% end %> ``` @@ -356,59 +370,60 @@ Supposing we use the same `_box` partial from above, this would produce the same View Paths ---------- -TODO... +When rendering a response, the controller needs to resolve where the different +views are located. By default it only looks inside the `app/views` directory. -Overview of helpers provided by Action View -------------------------------------------- +We can add other locations and give them a certain precedence when resolving +paths using the `prepend_view_path` and `append_view_path` methods. -WIP: Not all the helpers are listed here. For a full list see the [API documentation](http://api.rubyonrails.org/classes/ActionView/Helpers.html) +### Prepend view path -The following is only a brief overview summary of the helpers available in Action View. It's recommended that you review the [API Documentation](http://api.rubyonrails.org/classes/ActionView/Helpers.html), which covers all of the helpers in more detail, but this should serve as a good starting point. +This can be helpful for example, when we want to put views inside a different +directory for subdomains. -### AssetTagHelper +We can do this by using: -This module provides methods for generating HTML that links views to assets such as images, JavaScript files, stylesheets, and feeds. +```ruby +prepend_view_path "app/views/#{request.subdomain}" +``` -By default, Rails links to these assets on the current host in the public folder, but you can direct Rails to link to assets from a dedicated assets server by setting `config.action_controller.asset_host` in the application configuration, typically in `config/environments/production.rb`. For example, let's say your asset host is `assets.example.com`: +Then Action View will look first in this directory when resolving views. + +### Append view path + +Similarly, we can append paths: ```ruby -config.action_controller.asset_host = "assets.example.com" -image_tag("rails.png") # => <img src="http://assets.example.com/images/rails.png" alt="Rails" /> +append_view_path "app/views/direct" ``` -#### register_javascript_expansion +This will add `app/views/direct` to the end of the lookup paths. -Register one or more JavaScript files to be included when symbol is passed to javascript_include_tag. This method is typically intended to be called from plugin initialization to register JavaScript files that the plugin installed in `vendor/assets/javascripts`. +Overview of helpers provided by Action View +------------------------------------------- -```ruby -ActionView::Helpers::AssetTagHelper.register_javascript_expansion monkey: ["head", "body", "tail"] +WIP: Not all the helpers are listed here. For a full list see the [API documentation](http://api.rubyonrails.org/classes/ActionView/Helpers.html) -javascript_include_tag :monkey # => - <script src="/assets/head.js"></script> - <script src="/assets/body.js"></script> - <script src="/assets/tail.js"></script> -``` +The following is only a brief overview summary of the helpers available in Action View. It's recommended that you review the [API Documentation](http://api.rubyonrails.org/classes/ActionView/Helpers.html), which covers all of the helpers in more detail, but this should serve as a good starting point. -#### register_stylesheet_expansion +### AssetTagHelper -Register one or more stylesheet files to be included when symbol is passed to `stylesheet_link_tag`. This method is typically intended to be called from plugin initialization to register stylesheet files that the plugin installed in `vendor/assets/stylesheets`. +This module provides methods for generating HTML that links views to assets such as images, JavaScript files, stylesheets, and feeds. -```ruby -ActionView::Helpers::AssetTagHelper.register_stylesheet_expansion monkey: ["head", "body", "tail"] +By default, Rails links to these assets on the current host in the public folder, but you can direct Rails to link to assets from a dedicated assets server by setting `config.action_controller.asset_host` in the application configuration, typically in `config/environments/production.rb`. For example, let's say your asset host is `assets.example.com`: -stylesheet_link_tag :monkey # => - <link href="/assets/head.css" media="screen" rel="stylesheet" /> - <link href="/assets/body.css" media="screen" rel="stylesheet" /> - <link href="/assets/tail.css" media="screen" rel="stylesheet" /> +```ruby +config.action_controller.asset_host = "assets.example.com" +image_tag("rails.png") # => <img src="http://assets.example.com/images/rails.png" /> ``` #### auto_discovery_link_tag -Returns a link tag that browsers and feed 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, Atom, or JSON feed. ```ruby auto_discovery_link_tag(:rss, "http://www.example.com/feed.rss", { title: "RSS Feed" }) # => - <link rel="alternate" type="application/rss+xml" title="RSS Feed" href="http://www.example.com/feed" /> + <link rel="alternate" type="application/rss+xml" title="RSS Feed" href="http://www.example.com/feed.rss" /> ``` #### image_path @@ -427,7 +442,7 @@ image_path("edit.png") # => /assets/edit-2d1a2db63fc738690021fedb5a65b68e.png #### image_url -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. +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 @@ -438,7 +453,7 @@ image_url("edit.png") # => http://www.example.com/assets/edit.png 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" /> +image_tag("icon.png") # => <img src="/assets/icon.png" /> ``` #### javascript_include_tag @@ -449,25 +464,6 @@ Returns an HTML script tag for each of the sources provided. You can pass in the javascript_include_tag "common" # => <script src="/assets/common.js"></script> ``` -If the application does not use the asset pipeline, to include the jQuery JavaScript library in your application, pass `:defaults` as the source. When using `:defaults`, if an `application.js` file exists in your `app/assets/javascripts` directory, it will be included as well. - -```ruby -javascript_include_tag :defaults -``` - -You can also include all JavaScript files in the `app/assets/javascripts` directory using `:all` as the source. - -```ruby -javascript_include_tag :all -``` - -You can also cache multiple JavaScript files into one file, which requires less HTTP connections to download and can better be compressed by gzip (leading to faster transfers). Caching will only happen if `ActionController::Base.perform_caching` is set to true (which is the case by default for the Rails production environment, but not for the development environment). - -```ruby -javascript_include_tag :all, cache: true # => - <script src="/javascripts/all.js"></script> -``` - #### javascript_path Computes the path to a JavaScript asset in the `app/assets/javascripts` directory. If the source filename has no extension, `.js` will be appended. Full paths from the document root will be passed through. Used internally by `javascript_include_tag` to build the script path. @@ -478,7 +474,7 @@ javascript_path "common" # => /assets/common.js #### javascript_url -Computes the url to a JavaScript asset in the `app/assets/javascripts` directory. This will call `javascript_path` internally and merge with your current host or your asset host. +Computes the URL to a JavaScript asset in the `app/assets/javascripts` directory. This will call `javascript_path` internally and merge with your current host or your asset host. ```ruby javascript_url "common" # => http://www.example.com/assets/common.js @@ -492,22 +488,9 @@ Returns a stylesheet link tag for the sources specified as arguments. If you don stylesheet_link_tag "application" # => <link href="/assets/application.css" media="screen" rel="stylesheet" /> ``` -You can also include all styles in the stylesheet directory using :all as the source: - -```ruby -stylesheet_link_tag :all -``` - -You can also cache multiple stylesheets into one file, which requires less HTTP connections and can better be compressed by gzip (leading to faster transfers). Caching will only happen if ActionController::Base.perform_caching is set to true (which is the case by default for the Rails production environment, but not for the development environment). - -```ruby -stylesheet_link_tag :all, cache: true -# => <link href="/assets/all.css" media="screen" rel="stylesheet" /> -``` - #### stylesheet_path -Computes the path to a stylesheet asset in the `app/assets/stylesheets` directory. If the source filename has no extension, .css will be appended. Full paths from the document root will be passed through. Used internally by stylesheet_link_tag to build the stylesheet path. +Computes the path to a stylesheet asset in the `app/assets/stylesheets` directory. If the source filename has no extension, `.css` will be appended. Full paths from the document root will be passed through. Used internally by `stylesheet_link_tag` to build the stylesheet path. ```ruby stylesheet_path "application" # => /assets/application.css @@ -515,7 +498,7 @@ stylesheet_path "application" # => /assets/application.css #### stylesheet_url -Computes the url to a stylesheet asset in the `app/assets/stylesheets` directory. This will call `stylesheet_path` internally and merge with your current host or your asset host. +Computes the URL to a stylesheet asset in the `app/assets/stylesheets` directory. This will call `stylesheet_path` internally and merge with your current host or your asset host. ```ruby stylesheet_url "application" # => http://www.example.com/assets/application.css @@ -551,7 +534,7 @@ end ```ruby atom_feed do |feed| feed.title("Articles Index") - feed.updated((@articles.first.created_at)) + feed.updated(@articles.first.created_at) @articles.each do |article| feed.entry(article) do |entry| @@ -584,7 +567,7 @@ This would add something like "Process data files (0.34523)" to the log, which y #### cache -A method for caching fragments of a view rather than an entire action or page. This technique is useful caching pieces like menus, lists of news topics, static HTML fragments, and so on. This method takes a block that contains the content you wish to cache. See `ActionController::Caching::Fragments` for more information. +A method for caching fragments of a view rather than an entire action or page. This technique is useful for caching pieces like menus, lists of news topics, static HTML fragments, and so on. This method takes a block that contains the content you wish to cache. See `AbstractController::Caching::Fragments` for more information. ```erb <% cache do %> @@ -725,7 +708,7 @@ Returns a select tag with options for each of the minutes 0 through 59 with the ```ruby # Generates a select field for minutes that defaults to the minutes for the time provided. -select_minute(Time.now + 6.hours) +select_minute(Time.now + 10.minutes) ``` #### select_month @@ -743,7 +726,7 @@ Returns a select tag with options for each of the seconds 0 through 59 with the ```ruby # Generates a select field for seconds that defaults to the seconds for the time provided -select_second(Time.now + 16.minutes) +select_second(Time.now + 16.seconds) ``` #### select_time @@ -808,9 +791,9 @@ third: Form helpers are designed to make working with models much easier compared to using just standard HTML elements by providing a set of methods for creating forms based on your models. This helper generates the HTML for forms, providing a method for each sort of input (e.g., text, password, select, and so on). When the form is submitted (i.e., when the user hits the submit button or form.submit is called via JavaScript), the form inputs will be bundled into the params object and passed back to the controller. -There are two types of form helpers: those that specifically work with model attributes and those that don't. This helper deals with those that work with model attributes; to see an example of form helpers that don't work with model attributes, check the ActionView::Helpers::FormTagHelper documentation. +There are two types of form helpers: those that specifically work with model attributes and those that don't. This helper deals with those that work with model attributes; to see an example of form helpers that don't work with model attributes, check the `ActionView::Helpers::FormTagHelper` documentation. -The core method of this helper, form_for, gives you the ability to create a form for a model instance; for example, let's say that you have a model Person and want to create a new instance of it: +The core method of this helper, `form_for`, gives you the ability to create a form for a model instance; for example, let's say that you have a model Person and want to create a new instance of it: ```html+erb # Note: a @person variable will have been created in the controller (e.g. @person = Person.new) @@ -824,20 +807,22 @@ The core method of this helper, form_for, gives you the ability to create a form The HTML generated for this would be: ```html -<form action="/people/create" method="post"> - <input id="person_first_name" name="person[first_name]" type="text" /> - <input id="person_last_name" name="person[last_name]" type="text" /> - <input name="commit" type="submit" value="Create" /> +<form class="new_person" id="new_person" action="/people" accept-charset="UTF-8" method="post"> + <input name="utf8" type="hidden" value="✓" /> + <input type="hidden" name="authenticity_token" value="lTuvBzs7ANygT0NFinXj98tfw3Emfm65wwYLbUvoWsK2pngccIQSUorM2C035M9dZswXgWTvKwFS8W5TVblpYw==" /> + <input type="text" name="person[first_name]" id="person_first_name" /> + <input type="text" name="person[last_name]" id="person_last_name" /> + <input type="submit" name="commit" value="Create" data-disable-with="Create" /> </form> ``` The params object created when this form is submitted would look like: ```ruby -{ "action" => "create", "controller" => "people", "person" => { "first_name" => "William", "last_name" => "Smith" } } +{"utf8" => "✓", "authenticity_token" => "lTuvBzs7ANygT0NFinXj98tfw3Emfm65wwYLbUvoWsK2pngccIQSUorM2C035M9dZswXgWTvKwFS8W5TVblpYw==", "person" => {"first_name" => "William", "last_name" => "Smith"}, "commit" => "Create", "controller" => "people", "action" => "create"} ``` -The params hash has a nested person value, which can therefore be accessed with params[:person] in the controller. +The params hash has a nested person value, which can therefore be accessed with `params[:person]` in the controller. #### check_box @@ -852,7 +837,7 @@ check_box("article", "validated") #### fields_for -Creates a scope around a specific model object like form_for, but doesn't create the form tags themselves. This makes fields_for suitable for specifying additional model objects in the same form: +Creates a scope around a specific model object like `form_for`, but doesn't create the form tags themselves. This makes `fields_for` suitable for specifying additional model objects in the same form: ```html+erb <%= form_for @person, url: { action: "update" } do |person_form| %> @@ -975,11 +960,11 @@ Returns `select` and `option` tags for the collection of existing return values Example object structure for use with this method: ```ruby -class Article < ActiveRecord::Base +class Article < ApplicationRecord belongs_to :author end -class Author < ActiveRecord::Base +class Author < ApplicationRecord has_many :articles def name_with_initial "#{first_name.first}. #{last_name}" @@ -1011,11 +996,11 @@ Returns `radio_button` tags for the collection of existing return values of `met Example object structure for use with this method: ```ruby -class Article < ActiveRecord::Base +class Article < ApplicationRecord belongs_to :author end -class Author < ActiveRecord::Base +class Author < ApplicationRecord has_many :articles def name_with_initial "#{first_name.first}. #{last_name}" @@ -1047,11 +1032,11 @@ Returns `check_box` tags for the collection of existing return values of `method Example object structure for use with this method: ```ruby -class Article < ActiveRecord::Base +class Article < ApplicationRecord has_and_belongs_to_many :authors end -class Author < ActiveRecord::Base +class Author < ApplicationRecord has_and_belongs_to_many :articles def name_with_initial "#{first_name.first}. #{last_name}" @@ -1077,14 +1062,6 @@ If `@article.author_ids` is [1], this would return: <input name="article[author_ids][]" type="hidden" value="" /> ``` -#### country_options_for_select - -Returns a string of option tags for pretty much any country in the world. - -#### country_select - -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 Returns a string of `option` tags, like `options_from_collection_for_select`, but groups them by `optgroup` tags based on the object relationships of the arguments. @@ -1092,12 +1069,12 @@ Returns a string of `option` tags, like `options_from_collection_for_select`, bu Example object structure for use with this method: ```ruby -class Continent < ActiveRecord::Base +class Continent < ApplicationRecord has_many :countries # attribs: id, name end -class Country < ActiveRecord::Base +class Country < ApplicationRecord belongs_to :continent # attribs: id, name, continent_id end @@ -1146,7 +1123,7 @@ Returns a string of option tags that have been compiled by iterating over the `c # options_from_collection_for_select(collection, value_method, text_method, selected = nil) ``` -For example, imagine a loop iterating over each person in @project.people to generate an input tag: +For example, imagine a loop iterating over each person in `@project.people` to generate an input tag: ```ruby options_from_collection_for_select(@project.people, "id", "name") @@ -1171,8 +1148,8 @@ If `@article.person_id` is 1, this would become: <select name="article[person_id]"> <option value=""></option> <option value="1" selected="selected">David</option> - <option value="2">Sam</option> - <option value="3">Tobias</option> + <option value="2">Eileen</option> + <option value="3">Rafael</option> </select> ``` @@ -1185,7 +1162,7 @@ Returns a string of option tags for pretty much any time zone in the world. 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") +time_zone_select("user", "time_zone") ``` #### date_field @@ -1240,7 +1217,7 @@ file_field_tag 'attachment' #### form_tag -Starts a form tag that points the action to an url configured with `url_for_options` just like `ActionController::Base#url_for`. +Starts a form tag that points the action to a URL configured with `url_for_options` just like `ActionController::Base#url_for`. ```html+erb <%= form_tag '/articles' do %> @@ -1361,22 +1338,6 @@ date_field_tag "dob" Provides functionality for working with JavaScript in your views. -#### button_to_function - -Returns a button that'll trigger a JavaScript function using the onclick handler. Examples: - -```ruby -button_to_function "Greeting", "alert('Hello world!')" -button_to_function "Delete", "if (confirm('Really?')) do_delete()" -button_to_function "Details" do |page| - page[:details].visual_effect :toggle_slide -end -``` - -#### define_javascript_functions - -Includes the Action Pack JavaScript libraries inside a single `script` tag. - #### escape_javascript Escape carrier returns and single and double quotes for JavaScript segments. @@ -1397,15 +1358,6 @@ alert('All is good') </script> ``` -#### link_to_function - -Returns a link that will trigger a JavaScript function using the onclick handler and return false after the fact. - -```ruby -link_to_function "Greeting", "alert('Hello world!')" -# => <a onclick="alert('Hello world!'); return false;" href="#">Greeting</a> -``` - ### NumberHelper Provides methods for converting numbers into formatted strings. Methods are provided for phone numbers, currency, percentage, precision, positional notation, and file size. @@ -1437,7 +1389,7 @@ number_to_percentage(100, precision: 0) # => 100% #### number_to_phone -Formats a number into a US phone number. +Formats a number into a phone number (US by default). ```ruby number_to_phone(1235551234) # => 123-555-1234 @@ -1457,7 +1409,7 @@ Formats a number with the specified level of `precision`, which defaults to 3. ```ruby number_with_precision(111.2345) # => 111.235 -number_with_precision(111.2345, 2) # => 111.23 +number_with_precision(111.2345, precision: 2) # => 111.23 ``` ### SanitizeHelper @@ -1472,7 +1424,7 @@ This sanitize helper will HTML encode all tags and strip all attributes that are sanitize @article.body ``` -If either the :attributes or :tags options are passed, only the mentioned tags and attributes are allowed and nothing else. +If either the `:attributes` or `:tags` options are passed, only the mentioned attributes and tags are allowed and nothing else. ```ruby sanitize @article.body, tags: %w(table tr td), attributes: %w(id class style) @@ -1494,12 +1446,12 @@ Sanitizes a block of CSS code. Strips all link tags from text leaving just the link text. ```ruby -strip_links("<a href="http://rubyonrails.org">Ruby on Rails</a>") +strip_links('<a href="http://rubyonrails.org">Ruby on Rails</a>') # => Ruby on Rails ``` ```ruby -strip_links("emails to <a href="mailto:me@email.com">me@email.com</a>.") +strip_links('emails to <a href="mailto:me@email.com">me@email.com</a>.') # => emails to me@email.com. ``` @@ -1511,7 +1463,7 @@ strip_links('Blog: <a href="http://myblog.com/">Visit</a>.') #### strip_tags(html) 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. +This functionality is powered by the rails-html-sanitizer gem. ```ruby strip_tags("Strip <i>these</i> tags!") @@ -1542,7 +1494,7 @@ Localized Views Action View has the ability to render different templates depending on the current locale. -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. +For example, suppose you have an `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. 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. diff --git a/guides/source/active_job_basics.md b/guides/source/active_job_basics.md index 953c29719d..914ef2c327 100644 --- a/guides/source/active_job_basics.md +++ b/guides/source/active_job_basics.md @@ -4,14 +4,14 @@ Active Job Basics ================= This guide provides you with all you need to get started in creating, -enqueueing and executing background jobs. +enqueuing 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. +* How to send emails from your application asynchronously. -------------------------------------------------------------------------------- @@ -20,7 +20,7 @@ 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 +of queuing 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. @@ -28,11 +28,15 @@ 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. +in place. 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. + +NOTE: Rails by default comes with an asynchronous queuing implementation that +runs jobs with an in-process thread pool. Jobs will run asynchronously, but any +jobs in the queue will be dropped upon restart. Creating a Job @@ -59,57 +63,69 @@ $ 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`. +`app/jobs`, just make sure that it inherits from `ApplicationJob`. Here's what a job looks like: ```ruby -class GuestsCleanupJob < ActiveJob::Base +class GuestsCleanupJob < ApplicationJob queue_as :default - def perform(*args) + def perform(*guests) # Do something later end end ``` +Note that you can define `perform` with as many arguments as you want. + ### Enqueue the Job Enqueue a job like so: ```ruby -# Enqueue a job to be performed as soon the queueing system is +# Enqueue a job to be performed as soon as the queuing system is # free. -MyJob.perform_later record +GuestsCleanupJob.perform_later guest ``` ```ruby # Enqueue a job to be performed tomorrow at noon. -MyJob.set(wait_until: Date.tomorrow.noon).perform_later(record) +GuestsCleanupJob.set(wait_until: Date.tomorrow.noon).perform_later(guest) ``` ```ruby # Enqueue a job to be performed 1 week from now. -MyJob.set(wait: 1.week).perform_later(record) +GuestsCleanupJob.set(wait: 1.week).perform_later(guest) ``` -That's it! +```ruby +# `perform_now` and `perform_later` will call `perform` under the hood so +# you can pass as many arguments as defined in the latter. +GuestsCleanupJob.perform_later(guest1, guest2, filter: 'some_filter') +``` +That's it! Job Execution ------------- -If no adapter is set, the job is immediately executed. +For enqueuing and executing jobs in production you need to set up a queuing backend, +that is to say you need to decide for a 3rd-party queuing library that Rails should use. +Rails itself only provides an in-process queuing system, which only keeps the jobs in RAM. +If the process crashes or the machine is reset, then all outstanding jobs are lost with the +default async backend. This may be fine for smaller apps or non-critical jobs, but most +production apps will need to pick a persistent backend. ### Backends -Active Job has built-in adapters for multiple queueing backends (Sidekiq, +Active Job has built-in adapters for multiple queuing 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: +You can easily set your queuing backend: ```ruby # config/application.rb @@ -123,6 +139,32 @@ module YourApp end ``` +You can also configure your backend on a per job basis. + +```ruby +class GuestsCleanupJob < ApplicationJob + self.queue_adapter = :resque + #.... +end + +# Now your job will use `resque` as it's backend queue adapter overriding what +# was configured in `config.active_job.queue_adapter`. +``` + +### Starting the Backend + +Since jobs run in parallel to your Rails application, most queuing libraries +require that you start a library-specific queuing service (in addition to +starting your Rails app) for the job processing to work. Refer to library +documentation for instructions on starting your queue backend. + +Here is a noncomprehensive list of documentation: + +- [Sidekiq](https://github.com/mperham/sidekiq/wiki/Active-Job) +- [Resque](https://github.com/resque/resque/wiki/ActiveJob) +- [Sneakers](https://github.com/jondot/sneakers/wiki/How-To:-Rails-Background-Jobs-with-ActiveJob) +- [Sucker Punch](https://github.com/brandonhilkert/sucker_punch#active-job) +- [Queue Classic](https://github.com/QueueClassic/queue_classic#active-job) Queues ------ @@ -131,7 +173,7 @@ 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 +class GuestsCleanupJob < ApplicationJob queue_as :low_priority #.... end @@ -148,8 +190,8 @@ module YourApp end end -# app/jobs/guests_cleanup.rb -class GuestsCleanupJob < ActiveJob::Base +# app/jobs/guests_cleanup_job.rb +class GuestsCleanupJob < ApplicationJob queue_as :low_priority #.... end @@ -171,8 +213,8 @@ module YourApp end end -# app/jobs/guests_cleanup.rb -class GuestsCleanupJob < ActiveJob::Base +# app/jobs/guests_cleanup_job.rb +class GuestsCleanupJob < ApplicationJob queue_as :low_priority #.... end @@ -194,7 +236,7 @@ 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 +class ProcessVideoJob < ApplicationJob queue_as do video = self.arguments.first if video.owner.premium? @@ -212,47 +254,55 @@ end ProcessVideoJob.perform_later(Video.last) ``` -NOTE: Make sure your queueing backend "listens" on your queue name. For some +NOTE: Make sure your queuing 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 +Active Job provides hooks to trigger logic during the life cycle of a job. Like +other callbacks in Rails, you can implement the callbacks as ordinary methods +and use a macro-style class method to register them as callbacks: ```ruby -class GuestsCleanupJob < ActiveJob::Base +class GuestsCleanupJob < ApplicationJob 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 + around_perform :around_cleanup def perform # Do something later end + + private + def around_cleanup(job) + # Do something before perform + yield + # Do something after perform + end end ``` +The macro-style class methods can also receive a block. Consider using this +style if the code inside your block is so short that it fits in a single line. +For example, you could send metrics for every job enqueued: + +```ruby +class ApplicationJob + before_enqueue { |job| $statsd.increment "#{job.name.underscore}.enqueue" } +end +``` + +### Available callbacks + +* `before_enqueue` +* `around_enqueue` +* `after_enqueue` +* `before_perform` +* `around_perform` +* `after_perform` + Action Mailer ------------ @@ -269,6 +319,25 @@ UserMailer.welcome(@user).deliver_now UserMailer.welcome(@user).deliver_later ``` +NOTE: Using the asynchronous queue from a Rake task (for example, to +send an email using `.deliver_later`) will generally not work because Rake will +likely end, causing the in-process thread pool to be deleted, before any/all +of the `.deliver_later` emails are processed. To avoid this problem, use +`.deliver_now` or run a persistent queue in development. + + +Internationalization +-------------------- + +Each job uses the `I18n.locale` set when the job was created. Useful if you send +emails asynchronously: + +```ruby +I18n.locale = :eo + +UserMailer.welcome(@user).deliver_later # Email will be localized to Esperanto. +``` + GlobalID -------- @@ -278,7 +347,7 @@ 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 +class TrashableCleanupJob < ApplicationJob def perform(trashable_class, trashable_id, depth) trashable = trashable_class.constantize.find(trashable_id) trashable.cleanup(depth) @@ -289,7 +358,7 @@ end Now you can simply do: ```ruby -class TrashableCleanupJob < ActiveJob::Base +class TrashableCleanupJob < ApplicationJob def perform(trashable, depth) trashable.cleanup(depth) end @@ -307,11 +376,11 @@ Active Job provides a way to catch exceptions raised during the execution of the job: ```ruby -class GuestsCleanupJob < ActiveJob::Base +class GuestsCleanupJob < ApplicationJob queue_as :default rescue_from(ActiveRecord::RecordNotFound) do |exception| - # Do something with the exception + # Do something with the exception end def perform @@ -319,3 +388,36 @@ class GuestsCleanupJob < ActiveJob::Base end end ``` + +### Retrying or Discarding failed jobs + +It's also possible to retry or discard a job if an exception is raised during execution. +For example: + +```ruby +class RemoteServiceJob < ApplicationJob + retry_on CustomAppException # defaults to 3s wait, 5 attempts + + discard_on ActiveJob::DeserializationError + + def perform(*args) + # Might raise CustomAppException or ActiveJob::DeserializationError + end +end +``` + +To get more details see the API Documentation for [ActiveJob::Exceptions](http://api.rubyonrails.org/classes/ActiveJob/Exceptions/ClassMethods.html). + +### Deserialization + +GlobalID allows serializing full Active Record objects passed to `#perform`. + +If a passed record is deleted after the job is enqueued but before the `#perform` +method is called Active Job will raise an `ActiveJob::DeserializationError` +exception. + +Job Testing +-------------- + +You can find detailed instructions on how to test your jobs in the +[testing guide](testing.html#testing-jobs). diff --git a/guides/source/active_model_basics.md b/guides/source/active_model_basics.md index 4b2bfaee2f..ee0472621b 100644 --- a/guides/source/active_model_basics.md +++ b/guides/source/active_model_basics.md @@ -8,12 +8,12 @@ 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. +* How an Active Record model behaves. +* How Callbacks and validations work. +* How serializers work. +* How Active Model integrates with the Rails internationalization (i18n) framework. -------------------------------------------------------------------------------- @@ -87,7 +87,7 @@ end ### Conversion If a class defines `persisted?` and `id` methods, then you can include the -`ActiveModel::Conversion` module in that class and call the Rails conversion +`ActiveModel::Conversion` module in that class, and call the Rails conversion methods on objects of that class. ```ruby @@ -156,16 +156,17 @@ person.changed? # => false person.first_name = "First Name" person.first_name # => "First Name" -# returns if any attribute has changed. +# returns true if any of the attributes have unsaved changes. person.changed? # => true # returns a list of attributes that have changed before saving. person.changed # => ["first_name"] -# returns a hash of the attributes that have changed with their original values. +# returns a Hash of the attributes that have changed with their original values. person.changed_attributes # => {"first_name"=>nil} -# returns a hash of changes, with the attribute names as the keys, and the values will be an array of the old and new value for that field. +# returns a Hash of changes, with the attribute names as the keys, and the +# values as an array of the old and new values for that field. person.changes # => {"first_name"=>[nil, "First Name"]} ``` @@ -179,7 +180,7 @@ person.first_name # => "First Name" person.first_name_changed? # => true ``` -Track what was the previous value of the attribute. +Track the previous value of the attribute. ```ruby # attr_name_was accessor @@ -187,7 +188,7 @@ person.first_name_was # => nil ``` Track both previous and current value of the changed attribute. Returns an array -if changed, else returns nil. +if changed, otherwise returns nil. ```ruby # attr_name_change @@ -197,7 +198,7 @@ person.last_name_change # => nil ### Validations -`ActiveModel::Validations` module adds the ability to validate class objects +The `ActiveModel::Validations` module adds the ability to validate objects like in Active Record. ```ruby @@ -225,7 +226,7 @@ person.valid? # => raises ActiveModel::StrictValidationFa ### Naming -`ActiveModel::Naming` adds a number of class methods which make the naming and routing +`ActiveModel::Naming` adds a number of class methods which make 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. @@ -248,7 +249,7 @@ Person.model_name.singular_route_key # => "person" ### Model -`ActiveModel::Model` adds the ability to a class to work with Action Pack and +`ActiveModel::Model` adds the ability for a class to work with Action Pack and Action View right out of the box. ```ruby @@ -292,8 +293,8 @@ 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 +`ActiveModel::Serialization` provides 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 @@ -308,7 +309,7 @@ class Person end ``` -Now you can access a serialized hash of your object using the `serializable_hash`. +Now you can access a serialized Hash of your object using the `serializable_hash` method. ```ruby person = Person.new @@ -319,14 +320,14 @@ 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`. +Active Model also provides the `ActiveModel::Serializers::JSON` module +for JSON serializing / deserializing. This module automatically includes the +previously discussed `ActiveModel::Serialization` module. ##### ActiveModel::Serializers::JSON -To use the `ActiveModel::Serializers::JSON` you only need to change from -`ActiveModel::Serialization` to `ActiveModel::Serializers::JSON`. +To use `ActiveModel::Serializers::JSON` you only need to change the +module you are including from `ActiveModel::Serialization` to `ActiveModel::Serializers::JSON`. ```ruby class Person @@ -340,7 +341,8 @@ class Person end ``` -With the `as_json` you have a hash representing the model. +The `as_json` method, similar to `serializable_hash`, provides a Hash representing +the model. ```ruby person = Person.new @@ -349,8 +351,8 @@ 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: +You can also define the attributes for a model from a JSON string. +However, you need to define the `attributes=` method on your class: ```ruby class Person @@ -370,7 +372,7 @@ class Person end ``` -Now it is possible to create an instance of person and set the attributes using `from_json`. +Now it is possible to create an instance of `Person` and set attributes using `from_json`. ```ruby json = { name: 'Bob' }.to_json @@ -379,62 +381,6 @@ 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 an 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 an 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 @@ -446,8 +392,8 @@ class Person 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. +With the `human_attribute_name` method, you can transform attribute names into a +more human-readable format. The human-readable format is defined in your locale file(s). * config/locales/app.pt-BR.yml @@ -465,19 +411,18 @@ Person.human_attribute_name('name') # => "Nome" ### Lint Tests -`ActiveModel::Lint::Tests` allow you to test whether an object is compliant with +`ActiveModel::Lint::Tests` allows you to test whether an object is compliant with the Active Model API. -* app/models/person.rb +* `app/models/person.rb` ```ruby class Person include ActiveModel::Model - end ``` -* test/models/person_test.rb +* `test/models/person_test.rb` ```ruby require 'test_helper' @@ -485,14 +430,14 @@ the Active Model API. class PersonTest < ActiveSupport::TestCase include ActiveModel::Lint::Tests - def setup + setup do @model = Person.new end end ``` ```bash -$ rake test +$ rails test Run options: --seed 14596 @@ -512,20 +457,20 @@ 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 +password in an encrypted form. When you include this module, a `has_secure_password` class method is provided which defines -an accessor named `password` with certain validations on it. +a `password` accessor 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. +`ActiveModel::SecurePassword` depends on [`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) +2. Password should be equal to its confirmation (provided `password_confirmation` is passed along). +3. The maximum length of a password is 72 (required by `bcrypt` on which ActiveModel::SecurePassword depends) #### Examples @@ -546,10 +491,14 @@ person.password = 'aditya' person.password_confirmation = 'nomatch' person.valid? # => false -# When the length of password, exceeds 72. +# When the length of password exceeds 72. person.password = person.password_confirmation = 'a' * 100 person.valid? # => false +# When only password is supplied with no password_confirmation. +person.password = 'aditya' +person.valid? # => true + # 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 6551ba0389..9be9c6c7b7 100644 --- a/guides/source/active_record_basics.md +++ b/guides/source/active_record_basics.md @@ -20,7 +20,7 @@ After reading this guide, you will know: What is Active Record? ---------------------- -Active Record is the M in [MVC](http://en.wikipedia.org/wiki/Model%E2%80%93view%E2%80%93controller) - the +Active Record is the M in [MVC](https://en.wikipedia.org/wiki/Model%E2%80%93view%E2%80%93controller) - 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 @@ -38,7 +38,7 @@ 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 +[Object Relational Mapping](https://en.wikipedia.org/wiki/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 @@ -74,8 +74,8 @@ 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 +pluralization mechanisms are very powerful, being capable of pluralizing (and +singularizing) 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: @@ -104,7 +104,7 @@ depending on the purpose of these columns. your models. * **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 + Migrations](active_record_migrations.html) to create your tables, this column will be automatically created. There are also some optional column names that will add additional features @@ -132,17 +132,17 @@ Creating Active Record Models ----------------------------- 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: +subclass the `ApplicationRecord` class and you're good to go: ```ruby -class Product < ActiveRecord::Base +class Product < ApplicationRecord 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 -that the `products` table was created using an SQL sentence like: +that the `products` table was created using an SQL statement like: ```sql CREATE TABLE products ( @@ -168,11 +168,12 @@ 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 -name that should be used: +`ApplicationRecord` inherits from `ActiveRecord::Base`, which defines a +number of helpful methods. You can use the `ActiveRecord::Base.table_name=` +method to specify the table name that should be used: ```ruby -class Product < ActiveRecord::Base +class Product < ApplicationRecord self.table_name = "my_products" end ``` @@ -193,7 +194,7 @@ 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 +class Product < ApplicationRecord self.primary_key = "product_id" end ``` @@ -260,7 +261,7 @@ david = User.find_by(name: 'David') ```ruby # find all users named David who are Code Artists and sort by created_at in reverse chronological order -users = User.where(name: 'David', occupation: 'Code Artist').order('created_at DESC') +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 @@ -303,6 +304,17 @@ user = User.find_by(name: 'David') user.destroy ``` +If you'd like to delete several records in bulk, you may use `destroy_all` +method: + +```ruby +# find and delete all users named David +User.where(name: 'David').destroy_all + +# delete all users +User.destroy_all +``` + Validations ----------- @@ -313,14 +325,14 @@ already in the database, follows a specific format and many more. 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 +running: they return `false` when validation fails and they don't actually +perform any operations 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 +class User < ApplicationRecord validates :name, presence: true end @@ -350,7 +362,7 @@ database that Active Record supports using `rake`. Here's a migration that creates a table: ```ruby -class CreatePublications < ActiveRecord::Migration +class CreatePublications < ActiveRecord::Migration[5.0] def change create_table :publications do |t| t.string :title @@ -360,7 +372,7 @@ class CreatePublications < ActiveRecord::Migration t.string :publisher_type t.boolean :single_issue - t.timestamps null: false + t.timestamps end add_index :publications, :publication_type_id end @@ -368,9 +380,9 @@ end ``` 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`. +provides rollback features. To actually create the table, you'd run `rails db:migrate` +and to roll it back, `rails 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). +[Active Record Migrations guide](active_record_migrations.html). diff --git a/guides/source/active_record_callbacks.md b/guides/source/active_record_callbacks.md index 13989a3b33..630dafe632 100644 --- a/guides/source/active_record_callbacks.md +++ b/guides/source/active_record_callbacks.md @@ -31,12 +31,12 @@ Callbacks are methods that get called at certain moments of an object's life cyc In order to use the available callbacks, you need to register them. You can implement the callbacks as ordinary methods and use a macro-style class method to register them as callbacks: ```ruby -class User < ActiveRecord::Base +class User < ApplicationRecord validates :login, :email, presence: true before_validation :ensure_login_has_a_value - protected + private def ensure_login_has_a_value if login.nil? self.login = email unless email.blank? @@ -48,7 +48,7 @@ end The macro-style class methods can also receive a block. Consider using this style if the code inside your block is so short that it fits in a single line: ```ruby -class User < ActiveRecord::Base +class User < ApplicationRecord validates :login, :email, presence: true before_create do @@ -60,13 +60,13 @@ end Callbacks can also be registered to only fire on certain life cycle events: ```ruby -class User < ActiveRecord::Base +class User < ApplicationRecord before_validation :normalize_name, on: :create # :on takes an array as well after_validation :set_location, on: [ :create, :update ] - protected + private def normalize_name self.name = name.downcase.titleize end @@ -77,7 +77,7 @@ class User < ActiveRecord::Base end ``` -It is considered good practice to declare callback methods as protected or private. If left public, they can be called from outside of the model and violate the principle of object encapsulation. +It is considered good practice to declare callback methods as private. If left public, they can be called from outside of the model and violate the principle of object encapsulation. Available Callbacks ------------------- @@ -117,6 +117,10 @@ Here is a list with all the available Active Record callbacks, listed in the sam 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. +NOTE: `before_destroy` callbacks should be placed before `dependent: :destroy` +associations (or use the `prepend: true` option), to ensure they execute before +the records are deleted by `dependent: :destroy`. + ### `after_initialize` and `after_find` The `after_initialize` callback will be called whenever an Active Record object is instantiated, either by directly using `new` or when a record is loaded from the database. It can be useful to avoid the need to directly override your Active Record `initialize` method. @@ -126,7 +130,7 @@ The `after_find` callback will be called whenever Active Record loads a record f The `after_initialize` and `after_find` callbacks have no `before_*` counterparts, but they can be registered just like the other Active Record callbacks. ```ruby -class User < ActiveRecord::Base +class User < ApplicationRecord after_initialize do |user| puts "You have initialized an object!" end @@ -151,7 +155,7 @@ You have initialized an object! The `after_touch` callback will be called whenever an Active Record object is touched. ```ruby -class User < ActiveRecord::Base +class User < ApplicationRecord after_touch do |user| puts "You have touched an object" end @@ -168,14 +172,14 @@ You have touched an object It can be used along with `belongs_to`: ```ruby -class Employee < ActiveRecord::Base +class Employee < ApplicationRecord belongs_to :company, touch: true after_touch do puts 'An Employee was touched' end end -class Company < ActiveRecord::Base +class Company < ApplicationRecord has_many :employees after_touch :log_when_employees_or_company_touched @@ -202,15 +206,14 @@ The following methods trigger callbacks: * `create` * `create!` -* `decrement!` * `destroy` * `destroy!` * `destroy_all` -* `increment!` * `save` * `save!` * `save(validate: false)` * `toggle!` +* `touch` * `update_attribute` * `update` * `update!` @@ -243,7 +246,6 @@ Just as with validations, it is also possible to skip callbacks by using the fol * `increment` * `increment_counter` * `toggle` -* `touch` * `update_column` * `update_columns` * `update_all` @@ -256,9 +258,13 @@ Halting Execution As you start registering new callbacks for your models, they will be queued for execution. This queue will include all your model's validations, the registered callbacks, and the database operation to be executed. -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. +The whole callback chain is wrapped in a transaction. If any callback raises an exception, the execution chain gets halted and a ROLLBACK is issued. To intentionally stop a chain use: -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. +```ruby +throw :abort +``` + +WARNING. Any exception that is not `ActiveRecord::Rollback` or `ActiveRecord::RecordInvalid` will be re-raised by Rails after the callback chain is halted. Raising an exception other than `ActiveRecord::Rollback` or `ActiveRecord::RecordInvalid` 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 -------------------- @@ -266,11 +272,11 @@ Relational Callbacks 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 +class User < ApplicationRecord has_many :articles, dependent: :destroy end -class Article < ActiveRecord::Base +class Article < ApplicationRecord after_destroy :log_destroy_action def log_destroy_action @@ -290,34 +296,24 @@ Article destroyed Conditional Callbacks --------------------- -As with validations, we can also make the calling of a callback method conditional on the satisfaction of a given predicate. We can do this using the `:if` and `:unless` options, which can take a symbol, a string, a `Proc` or an `Array`. You may use the `:if` option when you want to specify under which conditions the callback **should** be called. If you want to specify the conditions under which the callback **should not** be called, then you may use the `:unless` option. +As with validations, we can also make the calling of a callback method conditional on the satisfaction of a given predicate. We can do this using the `:if` and `:unless` options, which can take a symbol, a `Proc` or an `Array`. You may use the `:if` option when you want to specify under which conditions the callback **should** be called. If you want to specify the conditions under which the callback **should not** be called, then you may use the `:unless` option. ### Using `:if` and `:unless` with a `Symbol` You can associate the `:if` and `:unless` options with a symbol corresponding to the name of a predicate method that will get called right before the callback. When using the `:if` option, the callback won't be executed if the predicate method returns false; when using the `:unless` option, the callback won't be executed if the predicate method returns true. This is the most common option. Using this form of registration it is also possible to register several different predicates that should be called to check if the callback should be executed. ```ruby -class Order < ActiveRecord::Base +class Order < ApplicationRecord before_save :normalize_card_number, if: :paid_with_card? end ``` -### Using `:if` and `:unless` with a String - -You can also use a string that will be evaluated using `eval` and hence needs to contain valid Ruby code. You should use this option only when the string represents a really short condition: - -```ruby -class Order < ActiveRecord::Base - before_save :normalize_card_number, if: "paid_with_card?" -end -``` - ### Using `:if` and `:unless` with a `Proc` Finally, it is possible to associate `:if` and `:unless` with a `Proc` object. This option is best suited when writing short validation methods, usually one-liners: ```ruby -class Order < ActiveRecord::Base +class Order < ApplicationRecord before_save :normalize_card_number, if: Proc.new { |order| order.paid_with_card? } end @@ -328,7 +324,7 @@ end When writing conditional callbacks, it is possible to mix both `:if` and `:unless` in the same callback declaration: ```ruby -class Comment < ActiveRecord::Base +class Comment < ApplicationRecord after_create :send_email_to_author, if: :author_wants_emails?, unless: Proc.new { |comment| comment.article.ignore_comments? } end @@ -354,7 +350,7 @@ end When declared inside a class, as above, the callback methods will receive the model object as a parameter. We can now use the callback class in the model: ```ruby -class PictureFile < ActiveRecord::Base +class PictureFile < ApplicationRecord after_destroy PictureFileCallbacks.new end ``` @@ -374,7 +370,7 @@ end If the callback method is declared this way, it won't be necessary to instantiate a `PictureFileCallbacks` object. ```ruby -class PictureFile < ActiveRecord::Base +class PictureFile < ApplicationRecord after_destroy PictureFileCallbacks end ``` @@ -398,8 +394,8 @@ end By using the `after_commit` callback we can account for this case. ```ruby -class PictureFile < ActiveRecord::Base - after_commit :delete_picture_file_from_disk, on: [:destroy] +class PictureFile < ApplicationRecord + after_commit :delete_picture_file_from_disk, on: :destroy def delete_picture_file_from_disk if File.exist?(filepath) @@ -409,7 +405,55 @@ class PictureFile < ActiveRecord::Base end ``` -NOTE: the `:on` option specifies when a callback will be fired. If you +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. +Since using `after_commit` callback only on create, update or delete is +common, there are aliases for those operations: + +* `after_create_commit` +* `after_update_commit` +* `after_destroy_commit` + +```ruby +class PictureFile < ApplicationRecord + after_destroy_commit :delete_picture_file_from_disk + + def delete_picture_file_from_disk + if File.exist?(filepath) + File.delete(filepath) + end + end +end +``` + +WARNING. The `after_commit` and `after_rollback` callbacks are called for all models created, updated, or destroyed within a transaction block. However, if an exception is raised within one of these callbacks, the exception will bubble up and any remaining `after_commit` or `after_rollback` methods will _not_ be executed. As such, if your callback code could raise an exception, you'll need to rescue it and handle it within the callback in order to allow other callbacks to run. + +WARNING. Using both `after_create_commit` and `after_update_commit` in the same model will only allow the last callback defined to take effect, and will override all others. + +```ruby +class User < ApplicationRecord + after_create_commit :log_user_saved_to_db + after_update_commit :log_user_saved_to_db + + private + def log_user_saved_to_db + puts 'User was saved to database' + end +end + +# prints nothing +>> @user = User.create + +# updating @user +>> @user.save +=> User was saved to database +``` + +To register callbacks for both create and update actions, use `after_commit` instead. + +```ruby +class User < ApplicationRecord + after_commit :log_user_saved_to_db, on: [:create, :update] +end +``` diff --git a/guides/source/active_record_migrations.md b/guides/source/active_record_migrations.md index de8bbc4174..ab3af438f5 100644 --- a/guides/source/active_record_migrations.md +++ b/guides/source/active_record_migrations.md @@ -12,7 +12,7 @@ After reading this guide, you will know: * The generators you can use to create them. * The methods Active Record provides to manipulate your database. -* The Rake tasks that manipulate migrations and your schema. +* The bin/rails tasks that manipulate migrations and your schema. * How migrations relate to `schema.rb`. -------------------------------------------------------------------------------- @@ -21,7 +21,7 @@ Migration Overview ------------------ Migrations are a convenient way to -[alter your database schema over time](http://en.wikipedia.org/wiki/Schema_migration) +[alter your database schema over time](https://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. @@ -35,13 +35,13 @@ history to the latest version. Active Record will also update your Here's an example of a migration: ```ruby -class CreateProducts < ActiveRecord::Migration +class CreateProducts < ActiveRecord::Migration[5.0] def change create_table :products do |t| t.string :name t.text :description - t.timestamps null: false + t.timestamps end end end @@ -72,7 +72,7 @@ If you wish for a migration to do something that Active Record doesn't know how to reverse, you can use `reversible`: ```ruby -class ChangeProductsPrice < ActiveRecord::Migration +class ChangeProductsPrice < ActiveRecord::Migration[5.0] def change reversible do |dir| change_table :products do |t| @@ -87,7 +87,7 @@ end Alternatively, you can use `up` and `down` instead of `change`: ```ruby -class ChangeProductsPrice < ActiveRecord::Migration +class ChangeProductsPrice < ActiveRecord::Migration[5.0] def up change_table :products do |t| t.change :price, :string @@ -129,7 +129,7 @@ $ bin/rails generate migration AddPartNumberToProducts This will create an empty but appropriately named migration: ```ruby -class AddPartNumberToProducts < ActiveRecord::Migration +class AddPartNumberToProducts < ActiveRecord::Migration[5.0] def change end end @@ -146,7 +146,7 @@ $ bin/rails generate migration AddPartNumberToProducts part_number:string will generate ```ruby -class AddPartNumberToProducts < ActiveRecord::Migration +class AddPartNumberToProducts < ActiveRecord::Migration[5.0] def change add_column :products, :part_number, :string end @@ -162,7 +162,7 @@ $ bin/rails generate migration AddPartNumberToProducts part_number:string:index will generate ```ruby -class AddPartNumberToProducts < ActiveRecord::Migration +class AddPartNumberToProducts < ActiveRecord::Migration[5.0] def change add_column :products, :part_number, :string add_index :products, :part_number @@ -180,7 +180,7 @@ $ bin/rails generate migration RemovePartNumberFromProducts part_number:string generates ```ruby -class RemovePartNumberFromProducts < ActiveRecord::Migration +class RemovePartNumberFromProducts < ActiveRecord::Migration[5.0] def change remove_column :products, :part_number, :string end @@ -196,7 +196,7 @@ $ bin/rails generate migration AddDetailsToProducts part_number:string price:dec generates ```ruby -class AddDetailsToProducts < ActiveRecord::Migration +class AddDetailsToProducts < ActiveRecord::Migration[5.0] def change add_column :products, :part_number, :string add_column :products, :price, :decimal @@ -215,7 +215,7 @@ $ bin/rails generate migration CreateProducts name:string part_number:string generates ```ruby -class CreateProducts < ActiveRecord::Migration +class CreateProducts < ActiveRecord::Migration[5.0] def change create_table :products do |t| t.string :name @@ -229,7 +229,7 @@ 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 +Also, the generator accepts column type as `references` (also available as `belongs_to`). For instance: ```bash @@ -239,14 +239,15 @@ $ bin/rails generate migration AddUserRefToProducts user:references generates ```ruby -class AddUserRefToProducts < ActiveRecord::Migration +class AddUserRefToProducts < ActiveRecord::Migration[5.0] def change - add_reference :products, :user, index: true, foreign_key: true + add_reference :products, :user, foreign_key: true end end ``` This migration will create a `user_id` column and appropriate index. +For more `add_reference` options, visit the [API documentation](http://api.rubyonrails.org/classes/ActiveRecord/ConnectionAdapters/SchemaStatements.html#method-i-add_reference). There is also a generator which will produce join tables if `JoinTable` is part of the name: @@ -257,7 +258,7 @@ $ bin/rails g migration CreateJoinTableCustomerProduct customer product will produce the following migration: ```ruby -class CreateJoinTableCustomerProduct < ActiveRecord::Migration +class CreateJoinTableCustomerProduct < ActiveRecord::Migration[5.0] def change create_join_table :customers, :products do |t| # t.index [:customer_id, :product_id] @@ -281,13 +282,13 @@ $ bin/rails generate model Product name:string description:text will create a migration that looks like this ```ruby -class CreateProducts < ActiveRecord::Migration +class CreateProducts < ActiveRecord::Migration[5.0] def change create_table :products do |t| t.string :name t.text :description - t.timestamps null: false + t.timestamps end end end @@ -309,10 +310,10 @@ $ bin/rails generate migration AddDetailsToProducts 'price:decimal{5,2}' supplie will produce a migration that looks like this ```ruby -class AddDetailsToProducts < ActiveRecord::Migration +class AddDetailsToProducts < ActiveRecord::Migration[5.0] def change add_column :products, :price, :decimal, precision: 5, scale: 2 - add_reference :products, :supplier, polymorphic: true, index: true + add_reference :products, :supplier, polymorphic: true end end ``` @@ -352,13 +353,19 @@ create_table :products, options: "ENGINE=BLACKHOLE" do |t| end ``` -will append `ENGINE=BLACKHOLE` to the SQL statement used to create the table -(when using MySQL, the default is `ENGINE=InnoDB`). +will append `ENGINE=BLACKHOLE` to the SQL statement used to create the table. + +Also you can pass the `:comment` option with any description for the table +that will be stored in database itself and can be viewed with database administration +tools, such as MySQL Workbench or PgAdmin III. It's highly recommended to specify +comments in migrations for applications with large databases as it helps people +to understand data model and generate documentation. +Currently only the MySQL and PostgreSQL adapters support comments. ### Creating a Join Table -Migration method `create_join_table` creates an HABTM join table. A typical use -would be: +The migration method `create_join_table` creates an HABTM (has and belongs to +many) join table. A typical use would be: ```ruby create_join_table :products, :categories @@ -367,23 +374,21 @@ 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. This can be overridden by specifying the `:column_options` -option. +option: ```ruby -create_join_table :products, :categories, column_options: {null: true} +create_join_table :products, :categories, column_options: { null: true } ``` -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: +By default, the name of the join table comes from the union of the first two +arguments provided to create_join_table, in alphabetical order. +To customize the name of the table, provide a `:table_name` option: ```ruby create_join_table :products, :categories, table_name: :categorization ``` -will create a `categorization` table. +creates a `categorization` table. `create_join_table` also accepts a block, which you can use to add indices (which are not created by default) or additional columns: @@ -423,21 +428,23 @@ change_column :products, :part_number, :text ``` This changes the column `part_number` on products table to be a `:text` field. +Note that `change_column` command is irreversible. Besides `change_column`, the `change_column_null` and `change_column_default` -methods are used specifically to change a not null constraint and default values of a -column. +methods are used specifically to change a not null constraint and default +values of a column. ```ruby change_column_null :products, :name, false -change_column_default :products, :approved, false +change_column_default :products, :approved, from: true, to: false ``` This sets `:name` field on products to a `NOT NULL` column and the default -value of the `:approved` field to false. +value of the `:approved` field from true to false. -TIP: Unlike `change_column` (and `change_column_default`), `change_column_null` -is reversible. +Note: You could also write the above `change_column_default` migration as +`change_column_default :products, :approved, false`, but unlike the previous +example, this would make your migration irreversible. ### Column Modifiers @@ -454,12 +461,13 @@ number of digits after the decimal point. 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. +* `comment` Adds a comment for the column. Some adapters may support additional options; see the adapter specific API docs for further information. +NOTE: `null` and `default` cannot be specified via command line. + ### Foreign Keys While it's not required you might want to add foreign key constraints to @@ -475,7 +483,8 @@ 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. +`fk_rails_` followed by 10 characters which are deterministically +generated from the `from_table` and `column`. There is a `:name` option to specify a different name if needed. NOTE: Active Record only supports single column foreign keys. `execute` and @@ -501,7 +510,7 @@ If the helpers provided by Active Record aren't enough you can use the `execute` method to execute arbitrary SQL: ```ruby -Product.connection.execute('UPDATE `products` SET `price`=`free` WHERE 1') +Product.connection.execute("UPDATE products SET price = 'free' WHERE 1=1") ``` For more details and examples of individual methods, check the API documentation. @@ -521,20 +530,27 @@ majority of cases, where Active Record knows how to reverse the migration automatically. Currently, the `change` method supports only these migration definitions: -* `add_column` -* `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) -* `remove_timestamps` -* `rename_column` -* `rename_index` -* `remove_reference` -* `rename_table` +* add_column +* add_foreign_key +* add_index +* add_reference +* add_timestamps +* change_column_default (must supply a :from and :to option) +* change_column_null +* create_join_table +* create_table +* disable_extension +* drop_join_table +* drop_table (must supply a block) +* enable_extension +* remove_column (must supply a type) +* remove_foreign_key (must supply a second table) +* remove_index +* remove_reference +* remove_timestamps +* rename_column +* rename_index +* rename_table `change_table` is also reversible, as long as the block does not call `change`, `change_default` or `remove`. @@ -554,10 +570,10 @@ 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 and what else to do when reverting it. For example: ```ruby -class ExampleMigration < ActiveRecord::Migration +class ExampleMigration < ActiveRecord::Migration[5.0] def change create_table :distributors do |t| t.string :zipcode @@ -606,11 +622,11 @@ schema, and the `down` method of your migration should revert the transformations done by the `up` method. In other words, the database schema should be unchanged if you do an `up` followed by a `down`. For example, if you create a table in the `up` method, you should drop it in the `down` method. It -is wise to reverse the transformations in precisely the reverse order they were +is wise to perform the transformations in precisely the reverse order they were made in the `up` method. The example in the `reversible` section is equivalent to: ```ruby -class ExampleMigration < ActiveRecord::Migration +class ExampleMigration < ActiveRecord::Migration[5.0] def up create_table :distributors do |t| t.string :zipcode @@ -651,9 +667,9 @@ can't be done. You can use Active Record's ability to rollback migrations using the `revert` method: ```ruby -require_relative '2012121212_example_migration' +require_relative '20121212123456_example_migration' -class FixupExampleMigration < ActiveRecord::Migration +class FixupExampleMigration < ActiveRecord::Migration[5.0] def change revert ExampleMigration @@ -671,7 +687,7 @@ is later decided it would be best to use Active Record validations, in place of the `CHECK` constraint, to verify the zipcode. ```ruby -class DontUseConstraintForZipcodeValidationMigration < ActiveRecord::Migration +class DontUseConstraintForZipcodeValidationMigration < ActiveRecord::Migration[5.0] def change revert do # copy-pasted code from ExampleMigration @@ -711,10 +727,10 @@ you will have to use `structure.sql` as dump method. See Running Migrations ------------------ -Rails provides a set of Rake tasks to run certain sets of migrations. +Rails provides a set of bin/rails tasks to run certain sets of migrations. -The very first migration related Rake task you will use will probably be -`rake db:migrate`. In its most basic form it just runs the `change` or `up` +The very first migration related bin/rails task you will use will probably be +`rails db:migrate`. In its most basic form it just runs the `change` or `up` 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. @@ -728,7 +744,7 @@ is the numerical prefix on the migration's filename. For example, to migrate to version 20080906120000 run: ```bash -$ bin/rake db:migrate VERSION=20080906120000 +$ bin/rails db:migrate VERSION=20080906120000 ``` If version 20080906120000 is greater than the current version (i.e., it is @@ -745,7 +761,7 @@ mistake in it and wish to correct it. Rather than tracking down the version number associated with the previous migration you can run: ```bash -$ bin/rake db:rollback +$ bin/rails db:rollback ``` This will rollback the latest migration, either by reverting the `change` @@ -753,7 +769,7 @@ method or by running the `down` method. If you need to undo several migrations you can provide a `STEP` parameter: ```bash -$ bin/rake db:rollback STEP=3 +$ bin/rails db:rollback STEP=3 ``` will revert the last 3 migrations. @@ -763,26 +779,26 @@ 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: ```bash -$ bin/rake db:migrate:redo STEP=3 +$ bin/rails db:migrate:redo STEP=3 ``` -Neither of these Rake tasks do anything you could not do with `db:migrate`. They +Neither of these bin/rails 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 +The `rails 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 and set it up again. This is -functionally equivalent to `rake db:drop db:setup`. +The `rails db:reset` task will drop the database and set it up again. This is +functionally equivalent to `rails 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 +contents of the current `db/schema.rb` or `db/structure.sql` file. If a migration can't be rolled back, +`rails 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 @@ -793,7 +809,7 @@ the corresponding migration will have its `change`, `up` or `down` method invoked, for example: ```bash -$ bin/rake db:migrate:up VERSION=20080906120000 +$ bin/rails db:migrate:up VERSION=20080906120000 ``` will run the 20080906120000 migration by running the `change` method (or the @@ -803,13 +819,13 @@ Active Record believes that it has already been run. ### Running Migrations in Different Environments -By default running `rake db:migrate` will run in the `development` environment. +By default running `bin/rails db:migrate` will run in the `development` environment. To run migrations against another environment you can specify it using the `RAILS_ENV` environment variable while running the command. For example to run migrations against the `test` environment you could run: ```bash -$ bin/rake db:migrate RAILS_ENV=test +$ bin/rails db:migrate RAILS_ENV=test ``` ### Changing the Output of Running Migrations @@ -835,13 +851,13 @@ Several methods are provided in migrations that allow you to control all this: For example, this migration: ```ruby -class CreateProducts < ActiveRecord::Migration +class CreateProducts < ActiveRecord::Migration[5.0] def change suppress_messages do create_table :products do |t| t.string :name t.text :description - t.timestamps null: false + t.timestamps end end @@ -870,18 +886,18 @@ generates the following output == CreateProducts: migrated (10.0054s) ======================================= ``` -If you want Active Record to not output anything, then running `rake db:migrate +If you want Active Record to not output anything, then running `rails db:migrate VERBOSE=false` will suppress all output. Changing Existing Migrations ---------------------------- Occasionally you will make a mistake when writing a migration. If you have -already run the migration then you cannot just edit the migration and run the +already run the migration, then you cannot just edit the migration and run the migration again: Rails thinks it has already run the migration and so will do -nothing when you run `rake db:migrate`. You must rollback the migration (for -example with `rake db:rollback`), edit your migration and then run -`rake db:migrate` to run the corrected version. +nothing when you run `rails db:migrate`. You must rollback the migration (for +example with `bin/rails db:rollback`), edit your migration and then run +`rails db:migrate` to run the corrected version. In general, editing existing migrations is not a good idea. You will be creating extra work for yourself and your co-workers and cause major headaches @@ -927,7 +943,7 @@ There are two ways to dump the schema. This is set in `config/application.rb` by the `config.active_record.schema_format` setting, which may be either `:sql` or `:ruby`. -If `:ruby` is selected then the schema is stored in `db/schema.rb`. If you look +If `:ruby` is selected, then the schema is stored in `db/schema.rb`. If you look at this file you'll find that it looks an awful lot like one very big migration: @@ -941,10 +957,10 @@ ActiveRecord::Schema.define(version: 20080906171750) do create_table "products", force: true do |t| t.string "name" - t.text "description" + t.text "description" t.datetime "created_at" t.datetime "updated_at" - t.string "part_number" + t.string "part_number" end end ``` @@ -955,16 +971,16 @@ on. Because this is database-independent, it could be loaded into any database 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 triggers, stored procedures or check constraints. 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`. +NOTE: `db/schema.rb` cannot express database specific items such as triggers, +sequences, stored procedures or check constraints, etc. Please note that while +custom SQL statements can be run in migrations, these statements cannot be reconstituted +by the schema dumper. 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 +rails task) into `db/structure.sql`. For example, for PostgreSQL, the `pg_dump` +utility is used. For MySQL and MariaDB, 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 @@ -1003,10 +1019,13 @@ such features, the `execute` method can be used to execute arbitrary SQL. Migrations and Seed Data ------------------------ -Some people use migrations to add data to the database: +The main purpose of Rails' migration feature is to issue commands that modify the +schema using a consistent process. Migrations can also be used +to add or modify data. This is useful in an existing database that can't be destroyed +and recreated, such as a production database. ```ruby -class AddInitialProducts < ActiveRecord::Migration +class AddInitialProducts < ActiveRecord::Migration[5.0] def up 5.times do |i| Product.create(name: "Product ##{i}", description: "A product.") @@ -1019,9 +1038,11 @@ class AddInitialProducts < ActiveRecord::Migration end ``` -However, Rails has a 'seeds' feature that should be used for seeding a database -with initial data. It's a really simple feature: just fill up `db/seeds.rb` -with some Ruby code, and run `rake db:seed`: +To add initial data after a database is created, Rails has a built-in +'seeds' feature that makes the process quick and easy. This is especially +useful when reloading the database frequently in development and test environments. +It's easy to get started with this feature: just fill up `db/seeds.rb` with some +Ruby code, and run `rails db:seed`: ```ruby 5.times do |i| diff --git a/guides/source/active_record_postgresql.md b/guides/source/active_record_postgresql.md index 4d9c1776f4..58c61f0864 100644 --- a/guides/source/active_record_postgresql.md +++ b/guides/source/active_record_postgresql.md @@ -14,7 +14,7 @@ After reading this guide, you will know: -------------------------------------------------------------------------------- -In order to use the PostgreSQL adapter you need to have at least version 8.2 +In order to use the PostgreSQL adapter you need to have at least version 9.1 installed. Older versions are not supported. To get started with PostgreSQL have a look at the @@ -29,8 +29,8 @@ 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) +* [type definition](https://www.postgresql.org/docs/current/static/datatype-binary.html) +* [functions and operators](https://www.postgresql.org/docs/current/static/functions-binarystring.html) ```ruby # db/migrate/20140207133952_create_documents.rb @@ -39,7 +39,7 @@ create_table :documents do |t| end # app/models/document.rb -class Document < ActiveRecord::Base +class Document < ApplicationRecord end # Usage @@ -49,8 +49,8 @@ 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) +* [type definition](https://www.postgresql.org/docs/current/static/arrays.html) +* [functions and operators](https://www.postgresql.org/docs/current/static/functions-array.html) ```ruby # db/migrate/20140207133952_create_books.rb @@ -63,7 +63,7 @@ add_index :books, :tags, using: 'gin' add_index :books, :ratings, using: 'gin' # app/models/book.rb -class Book < ActiveRecord::Base +class Book < ApplicationRecord end # Usage @@ -83,9 +83,10 @@ Book.where("array_length(ratings, 1) >= 3") ### Hstore -* [type definition](http://www.postgresql.org/docs/9.3/static/hstore.html) +* [type definition](https://www.postgresql.org/docs/current/static/hstore.html) +* [functions and operators](https://www.postgresql.org/docs/current/static/hstore.html#AEN179902) -NOTE: you need to enable the `hstore` extension to use hstore. +NOTE: You need to enable the `hstore` extension to use hstore. ```ruby # db/migrate/20131009135255_create_profiles.rb @@ -97,7 +98,7 @@ ActiveRecord::Schema.define do end # app/models/profile.rb -class Profile < ActiveRecord::Base +class Profile < ApplicationRecord end # Usage @@ -108,21 +109,29 @@ profile.settings # => {"color"=>"blue", "resolution"=>"800x600"} profile.settings = {"color" => "yellow", "resolution" => "1280x1024"} profile.save! + +Profile.where("settings->'color' = ?", "yellow") +# => #<ActiveRecord::Relation [#<Profile id: 1, settings: {"color"=>"yellow", "resolution"=>"1280x1024"}>]> ``` -### JSON +### JSON and JSONB -* [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) +* [type definition](https://www.postgresql.org/docs/current/static/datatype-json.html) +* [functions and operators](https://www.postgresql.org/docs/current/static/functions-json.html) ```ruby # db/migrate/20131220144913_create_events.rb +# ... for json datatype: create_table :events do |t| t.json 'payload' end +# ... or for jsonb datatype: +create_table :events do |t| + t.jsonb 'payload' +end # app/models/event.rb -class Event < ActiveRecord::Base +class Event < ApplicationRecord end # Usage @@ -138,10 +147,10 @@ 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) +* [type definition](https://www.postgresql.org/docs/current/static/rangetypes.html) +* [functions and operators](https://www.postgresql.org/docs/current/static/functions-range.html) -This type is mapped to Ruby [`Range`](http://www.ruby-doc.org/core-2.1.1/Range.html) objects. +This type is mapped to Ruby [`Range`](http://www.ruby-doc.org/core-2.2.2/Range.html) objects. ```ruby # db/migrate/20130923065404_create_events.rb @@ -150,7 +159,7 @@ create_table :events do |t| end # app/models/event.rb -class Event < ActiveRecord::Base +class Event < ApplicationRecord end # Usage @@ -173,7 +182,7 @@ event.ends_at # => Thu, 13 Feb 2014 ### Composite Types -* [type definition](http://www.postgresql.org/docs/9.3/static/rowtypes.html) +* [type definition](https://www.postgresql.org/docs/current/static/rowtypes.html) Currently there is no special support for composite types. They are mapped to normal text columns: @@ -200,7 +209,7 @@ create_table :contacts do |t| end # app/models/contact.rb -class Contact < ActiveRecord::Base +class Contact < ApplicationRecord end # Usage @@ -213,22 +222,33 @@ contact.save! ### Enumerated Types -* [type definition](http://www.postgresql.org/docs/9.3/static/datatype-enum.html) +* [type definition](https://www.postgresql.org/docs/current/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 +def up + execute <<-SQL + CREATE TYPE article_status AS ENUM ('draft', 'published'); + SQL + create_table :articles do |t| + t.column :status, :article_status + end +end + +# NOTE: It's important to drop table before dropping enum. +def down + drop_table :articles + + execute <<-SQL + DROP TYPE article_status; + SQL end # app/models/article.rb -class Article < ActiveRecord::Base +class Article < ApplicationRecord end # Usage @@ -240,20 +260,50 @@ article.status = "published" article.save! ``` +To add a new value before/after existing one you should use [ALTER TYPE](https://www.postgresql.org/docs/current/static/sql-altertype.html): + +```ruby +# db/migrate/20150720144913_add_new_state_to_articles.rb +# NOTE: ALTER TYPE ... ADD VALUE cannot be executed inside of a transaction block so here we are using disable_ddl_transaction! +disable_ddl_transaction! + +def up + execute <<-SQL + ALTER TYPE article_status ADD VALUE IF NOT EXISTS 'archived' AFTER 'published'; + SQL +end +``` + +NOTE: ENUM values can't be dropped currently. You can read why [here](https://www.postgresql.org/message-id/29F36C7C98AB09499B1A209D48EAA615B7653DBC8A@mail2a.alliedtesting.com). + +Hint: to show all the values of the all enums you have, you should call this query in `bin/rails db` or `psql` console: + +```sql +SELECT n.nspname AS enum_schema, + t.typname AS enum_name, + e.enumlabel AS enum_value + FROM pg_type t + JOIN pg_enum e ON t.oid = e.enumtypid + JOIN pg_catalog.pg_namespace n ON n.oid = t.typnamespace +``` + ### 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) +* [type definition](https://www.postgresql.org/docs/current/static/datatype-uuid.html) +* [pgcrypto generator function](https://www.postgresql.org/docs/current/static/pgcrypto.html#AEN182570) +* [uuid-ossp generator functions](https://www.postgresql.org/docs/current/static/uuid-ossp.html) +NOTE: You need to enable the `pgcrypto` (only PostgreSQL >= 9.4) or `uuid-ossp` +extension to use uuid. ```ruby # db/migrate/20131220144913_create_revisions.rb create_table :revisions do |t| - t.column :identifier, :uuid + t.uuid :identifier end # app/models/revision.rb -class Revision < ActiveRecord::Base +class Revision < ApplicationRecord end # Usage @@ -263,10 +313,35 @@ revision = Revision.first revision.identifier # => "a0eebc99-9c0b-4ef8-bb6d-6bb9bd380a11" ``` +You can use `uuid` type to define references in migrations: + +```ruby +# db/migrate/20150418012400_create_blog.rb +enable_extension 'pgcrypto' unless extension_enabled?('pgcrypto') +create_table :posts, id: :uuid, default: 'gen_random_uuid()' + +create_table :comments, id: :uuid, default: 'gen_random_uuid()' do |t| + # t.belongs_to :post, type: :uuid + t.references :post, type: :uuid +end + +# app/models/post.rb +class Post < ApplicationRecord + has_many :comments +end + +# app/models/comment.rb +class Comment < ApplicationRecord + belongs_to :post +end +``` + +See [this section](#uuid-primary-keys) for more details on using UUIDs as primary key. + ### 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) +* [type definition](https://www.postgresql.org/docs/current/static/datatype-bit.html) +* [functions and operators](https://www.postgresql.org/docs/current/static/functions-bitstring.html) ```ruby # db/migrate/20131220144913_create_users.rb @@ -275,7 +350,7 @@ create_table :users, force: true do |t| end # app/models/device.rb -class User < ActiveRecord::Base +class User < ApplicationRecord end # Usage @@ -289,10 +364,10 @@ user.save! ### Network Address Types -* [type definition](http://www.postgresql.org/docs/9.3/static/datatype-net-types.html) +* [type definition](https://www.postgresql.org/docs/current/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) +[`IPAddr`](http://www.ruby-doc.org/stdlib-2.2.2/libdoc/ipaddr/rdoc/IPAddr.html) objects. The `macaddr` type is mapped to normal text. ```ruby @@ -304,7 +379,7 @@ create_table(:devices, force: true) do |t| end # app/models/device.rb -class Device < ActiveRecord::Base +class Device < ApplicationRecord end # Usage @@ -324,7 +399,7 @@ macbook.address ### Geometric Types -* [type definition](http://www.postgresql.org/docs/9.3/static/datatype-geometric.html) +* [type definition](https://www.postgresql.org/docs/current/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. @@ -333,17 +408,18 @@ 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. +NOTE: You need to enable the `pgcrypto` (only PostgreSQL >= 9.4) or `uuid-ossp` +extension to generate random 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| +enable_extension 'pgcrypto' unless extension_enabled?('pgcrypto') +create_table :devices, id: :uuid, default: 'gen_random_uuid()' do |t| t.string :kind end # app/models/device.rb -class Device < ActiveRecord::Base +class Device < ApplicationRecord end # Usage @@ -351,6 +427,9 @@ device = Device.create device.id # => "814865cd-5a1d-4771-9306-4268f188fe9e" ``` +NOTE: `gen_random_uuid()` (from `pgcrypto`) is assumed if no `:default` option was +passed to `create_table`. + Full Text Search ---------------- @@ -361,10 +440,10 @@ create_table :documents do |t| t.string 'body' end -execute "CREATE INDEX documents_idx ON documents USING gin(to_tsvector('english', title || ' ' || body));" +add_index :documents, "to_tsvector('english', title || ' ' || body)", using: :gin, name: 'documents_idx' # app/models/document.rb -class Document < ActiveRecord::Base +class Document < ApplicationRecord end # Usage @@ -378,7 +457,7 @@ Document.where("to_tsvector('english', title || ' ' || body) @@ to_tsquery(?)", Database Views -------------- -* [view creation](http://www.postgresql.org/docs/9.3/static/sql-createview.html) +* [view creation](https://www.postgresql.org/docs/current/static/sql-createview.html) Imagine you need to work with a legacy database containing the following table: @@ -414,7 +493,7 @@ CREATE VIEW articles AS SQL # app/models/article.rb -class Article < ActiveRecord::Base +class Article < ApplicationRecord self.primary_key = "id" def archive! update_attribute :archived, true @@ -429,9 +508,9 @@ second = Article.create! title: "Brace yourself", status: "draft", published_at: 1.month.ago -Article.count # => 1 -first.archive! Article.count # => 2 +first.archive! +Article.count # => 1 ``` NOTE: This application only cares about non-archived `Articles`. A view also diff --git a/guides/source/active_record_querying.md b/guides/source/active_record_querying.md index bef903b751..4e28e31a53 100644 --- a/guides/source/active_record_querying.md +++ b/guides/source/active_record_querying.md @@ -10,8 +10,8 @@ After reading this guide, you will know: * How to find records using a variety of methods and conditions. * 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 use dynamic finder methods. +* How to use method chaining to use multiple Active Record 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. @@ -25,7 +25,7 @@ Code examples throughout this guide will refer to one or more of the following m TIP: All of the following models use `id` as the primary key, unless specified otherwise. ```ruby -class Client < ActiveRecord::Base +class Client < ApplicationRecord has_one :address has_many :orders has_and_belongs_to_many :roles @@ -33,24 +33,24 @@ end ``` ```ruby -class Address < ActiveRecord::Base +class Address < ApplicationRecord belongs_to :client end ``` ```ruby -class Order < ActiveRecord::Base +class Order < ApplicationRecord belongs_to :client, counter_cache: true end ``` ```ruby -class Role < ActiveRecord::Base +class Role < ApplicationRecord has_and_belongs_to_many :clients end ``` -Active Record will perform queries on the database for you and is compatible with most database systems (MySQL, PostgreSQL and SQLite to name a few). Regardless of which database system you're using, the Active Record method format will always be the same. +Active Record will perform queries on the database for you and is compatible with most database systems, including MySQL, MariaDB, PostgreSQL, and SQLite. Regardless of which database system you're using, the Active Record method format will always be the same. Retrieving Objects from the Database ------------------------------------ @@ -59,7 +59,7 @@ To retrieve objects from the database, Active Record provides several finder met The methods are: -* `bind` +* `find` * `create_with` * `distinct` * `eager_load` @@ -69,6 +69,7 @@ The methods are: * `having` * `includes` * `joins` +* `left_outer_joins` * `limit` * `lock` * `none` @@ -80,10 +81,9 @@ The methods are: * `reorder` * `reverse_order` * `select` -* `uniq` * `where` -All of the above methods return an instance of `ActiveRecord::Relation`. +Finder methods that return a collection, such as `where` and `group`, return an instance of `ActiveRecord::Relation`. Methods that find a single entity, such as `find` and `first`, return a single instance of the model. The primary operation of `Model.find(options)` can be summarized as: @@ -118,7 +118,7 @@ You can also use this method to query for multiple objects. Call the `find` meth ```ruby # Find the clients with primary keys 1 and 10. -client = Client.find([1, 10]) # Or even Client.find(1, 10) +clients = Client.find([1, 10]) # Or even Client.find(1, 10) # => [#<Client id: 1, first_name: "Lifo">, #<Client id: 10, first_name: "Ryan">] ``` @@ -150,11 +150,11 @@ The `take` method returns `nil` if no record is found and no exception will be r You can pass in a numerical argument to the `take` method to return up to that number of results. For example ```ruby -client = Client.take(2) +clients = Client.take(2) # => [ - #<Client id: 1, first_name: "Lifo">, - #<Client id: 220, first_name: "Sara"> -] +# #<Client id: 1, first_name: "Lifo">, +# #<Client id: 220, first_name: "Sara"> +# ] ``` The SQL equivalent of the above is: @@ -169,7 +169,7 @@ TIP: The retrieved record may vary depending on the database engine. #### `first` -The `first` method finds the first record ordered by the primary key. For example: +The `first` method finds the first record ordered by primary key (default). For example: ```ruby client = Client.first @@ -184,15 +184,17 @@ SELECT * FROM clients ORDER BY clients.id ASC LIMIT 1 The `first` method returns `nil` if no matching record is found and no exception will be raised. +If your [default scope](active_record_querying.html#applying-a-default-scope) contains an order method, `first` will return the first record according to this ordering. + 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(3) +clients = Client.first(3) # => [ - #<Client id: 1, first_name: "Lifo">, - #<Client id: 2, first_name: "Fifo">, - #<Client id: 3, first_name: "Filo"> -] +# #<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: @@ -201,11 +203,24 @@ The SQL equivalent of the above is: SELECT * FROM clients ORDER BY clients.id ASC LIMIT 3 ``` +On a collection that is ordered using `order`, `first` will return the first record ordered by the specified attribute for `order`. + +```ruby +client = Client.order(:first_name).first +# => #<Client id: 2, first_name: "Fifo"> +``` + +The SQL equivalent of the above is: + +```sql +SELECT * FROM clients ORDER BY clients.first_name ASC LIMIT 1 +``` + The `first!` method behaves exactly like `first`, except that it will raise `ActiveRecord::RecordNotFound` if no matching record is found. #### `last` -The `last` method finds the last record ordered by the primary key. For example: +The `last` method finds the last record ordered by primary key (default). For example: ```ruby client = Client.last @@ -220,15 +235,17 @@ SELECT * FROM clients ORDER BY clients.id DESC LIMIT 1 The `last` method returns `nil` if no matching record is found and no exception will be raised. +If your [default scope](active_record_querying.html#applying-a-default-scope) contains an order method, `last` will return the last record according to this ordering. + You can pass in a numerical argument to the `last` method to return up to that number of results. For example ```ruby -client = Client.last(3) +clients = Client.last(3) # => [ - #<Client id: 219, first_name: "James">, - #<Client id: 220, first_name: "Sara">, - #<Client id: 221, first_name: "Russel"> -] +# #<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: @@ -237,6 +254,19 @@ The SQL equivalent of the above is: SELECT * FROM clients ORDER BY clients.id DESC LIMIT 3 ``` +On a collection that is ordered using `order`, `last` will return the last record ordered by the specified attribute for `order`. + +```ruby +client = Client.order(:first_name).last +# => #<Client id: 220, first_name: "Sara"> +``` + +The SQL equivalent of the above is: + +```sql +SELECT * FROM clients ORDER BY clients.first_name DESC LIMIT 1 +``` + The `last!` method behaves exactly like `last`, except that it will raise `ActiveRecord::RecordNotFound` if no matching record is found. #### `find_by` @@ -283,7 +313,7 @@ We often need to iterate over a large set of records, as when we send a newslett This may appear straightforward: ```ruby -# This is very inefficient when the users table has thousands of rows. +# This may consume too much memory if the table is big. User.all.each do |user| NewsMailer.weekly(user).deliver_now end @@ -297,7 +327,7 @@ TIP: The `find_each` and `find_in_batches` methods are intended for use in the b #### `find_each` -The `find_each` method retrieves a batch of records and then yields _each_ record to the block individually as a model. In the following example, `find_each` will retrieve 1000 records (the current default for both `find_each` and `find_in_batches`) and then yield each record individually to the block as a model. This process is repeated until all of the records have been processed: +The `find_each` method retrieves records in batches and then yields _each_ one to the block. In the following example, `find_each` retrieves users in batches of 1000 and yields them to the block one by one: ```ruby User.find_each do |user| @@ -305,7 +335,9 @@ User.find_each do |user| end ``` -To add conditions to a `find_each` operation you can chain other Active Record methods such as `where`: +This process is repeated, fetching more batches as needed, until all of the records have been processed. + +`find_each` works on model classes, as seen above, and also on relations: ```ruby User.where(weekly_subscriber: true).find_each do |user| @@ -313,11 +345,16 @@ User.where(weekly_subscriber: true).find_each do |user| end ``` -##### Options for `find_each` +as long as they have no ordering, since the method needs to force an order +internally to iterate. -The `find_each` method accepts most of the options allowed by the regular `find` method, except for `:order` and `:limit`, which are reserved for internal use by `find_each`. +If an order is present in the receiver the behaviour depends on the flag +`config.active_record.error_on_ignored_order`. If true, `ArgumentError` is +raised, otherwise the order is ignored and a warning issued, which is the +default. This can be overridden with the option `:error_on_ignore`, explained +below. -Two additional options, `:batch_size` and `:begin_at`, are available as well. +##### Options for `find_each` **`:batch_size`** @@ -329,47 +366,65 @@ User.find_each(batch_size: 5000) do |user| end ``` -**`:begin_at`** +**`:start`** -By default, records are fetched in ascending order of the primary key, which must be an integer. The `:begin_at` option allows you to configure the first ID of the sequence whenever the lowest ID is not the one you need. This would be useful, for example, if you wanted to resume an interrupted batch process, provided you saved the last processed ID as a checkpoint. +By default, records are fetched in ascending order of the primary key, which must be an integer. The `:start` option allows you to configure the first ID of the sequence whenever the lowest ID is not the one you need. This would be useful, for example, if you wanted to resume an interrupted batch process, provided you saved the last processed ID as a checkpoint. -For example, to send newsletters only to users with the primary key starting from 2000, and to retrieve them in batches of 5000: +For example, to send newsletters only to users with the primary key starting from 2000: ```ruby -User.find_each(begin_at: 2000, batch_size: 5000) do |user| +User.find_each(start: 2000) do |user| NewsMailer.weekly(user).deliver_now end ``` -Another example would be if you wanted multiple workers handling the same processing queue. You could have each worker handle 10000 records by setting the appropriate `:begin_at` option on each worker. +**`:finish`** -**`:end_at`** +Similar to the `:start` option, `:finish` allows you to configure the last ID of the sequence whenever the highest ID is not the one you need. +This would be useful, for example, if you wanted to run a batch process using a subset of records based on `:start` and `:finish`. -Similar to the `:begin_at` option, `:end_at` allows you to configure the last ID of the sequence whenever the highest ID is not the one you need. -This would be useful, for example, if you wanted to run a batch process, using a subset of records based on `:begin_at` and `:end_at` - -For example, to send newsletters only to users with the primary key starting from 2000 up to 10000 and to retrieve them in batches of 1000: +For example, to send newsletters only to users with the primary key starting from 2000 up to 10000: ```ruby -User.find_each(begin_at: 2000, end_at: 10000, batch_size: 5000) do |user| +User.find_each(start: 2000, finish: 10000) do |user| NewsMailer.weekly(user).deliver_now end ``` +Another example would be if you wanted multiple workers handling the same +processing queue. You could have each worker handle 10000 records by setting the +appropriate `:start` and `:finish` options on each worker. + +**`:error_on_ignore`** + +Overrides the application config to specify if an error should be raised when an +order is present in the relation. + #### `find_in_batches` The `find_in_batches` method is similar to `find_each`, since both retrieve batches of records. The difference is that `find_in_batches` yields _batches_ to the block as an array of models, instead of individually. The following example will yield to the supplied block an array of up to 1000 invoices at a time, with the final block containing any remaining invoices: ```ruby -# Give add_invoices an array of 1000 invoices at a time +# Give add_invoices an array of 1000 invoices at a time. Invoice.find_in_batches do |invoices| export.add_invoices(invoices) end ``` +`find_in_batches` works on model classes, as seen above, and also on relations: + +```ruby +Invoice.pending.find_in_batches do |invoices| + pending_invoices_export.add_invoices(invoices) +end +``` + +as long as they have no ordering, since the method needs to force an order +internally to iterate. + ##### Options for `find_in_batches` -The `find_in_batches` method accepts the same `:batch_size`, `:begin_at` and `:end_at` options as `find_each`. +The `find_in_batches` method accepts the same options as `find_each`. Conditions ---------- @@ -390,7 +445,7 @@ Now what if that number could vary, say as an argument from somewhere? The find Client.where("orders_count = ?", params[:orders]) ``` -Active Record will go through the first element in the conditions value and any additional elements will replace the question marks `(?)` in the first element. +Active Record will take the first argument as the conditions string and any additional arguments will replace the question marks `(?)` in it. If you want to specify multiple conditions: @@ -418,7 +473,7 @@ TIP: For more information on the dangers of SQL injection, see the [Ruby on Rail #### Placeholder Conditions -Similar to the `(?)` replacement style of params, you can also specify keys/values hash in your array conditions: +Similar to the `(?)` replacement style of params, you can also specify keys in your conditions string along with a corresponding keys/values hash: ```ruby Client.where("created_at >= :start_date AND created_at <= :end_date", @@ -429,7 +484,7 @@ This makes for clearer readability if you have a large number of variable condit ### Hash Conditions -Active Record also allows you to pass in hash conditions which can increase the readability of your conditions syntax. With hash conditions, you pass in a hash with keys of the fields you want conditionalised and the values of how you want to conditionalise them: +Active Record also allows you to pass in hash conditions which can increase the readability of your conditions syntax. With hash conditions, you pass in a hash with keys of the fields you want qualified and the values of how you want to qualify them: NOTE: Only equality, range and subset checking are possible with Hash conditions. @@ -439,6 +494,12 @@ NOTE: Only equality, range and subset checking are possible with Hash conditions Client.where(locked: true) ``` +This will generate SQL like this: + +```sql +SELECT * FROM clients WHERE (clients.locked = 1) +``` + The field name can also be a string: ```ruby @@ -452,8 +513,6 @@ 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)`. - #### Range Conditions ```ruby @@ -484,13 +543,30 @@ SELECT * FROM clients WHERE (clients.orders_count IN (1,3,5)) ### NOT Conditions -`NOT` SQL queries can be built by `where.not`. +`NOT` SQL queries can be built by `where.not`: ```ruby -Article.where.not(author: author) +Client.where.not(locked: true) +``` + +In other words, this query can be generated by calling `where` with no argument, then immediately chain with `not` passing `where` conditions. This will generate SQL like this: + +```sql +SELECT * FROM clients WHERE (clients.locked != 1) ``` -In other words, this query can be generated by calling `where` with no argument, then immediately chain with `not` passing `where` conditions. +### OR Conditions + +`OR` conditions between two relations can be built by calling `or` on the first +relation, and passing the second one as an argument. + +```ruby +Client.where(locked: true).or(Client.where(orders_count: [1,3,5])) +``` + +```sql +SELECT * FROM clients WHERE (clients.locked = 1 OR clients.orders_count IN (1,3,5)) +``` Ordering -------- @@ -529,12 +605,13 @@ Client.order("orders_count ASC, created_at DESC") Client.order("orders_count ASC", "created_at DESC") ``` -If you want to call `order` multiple times e.g. in different context, new order will append previous one +If you want to call `order` multiple times, subsequent orders will be appended to the first: ```ruby Client.order("orders_count ASC").order("created_at DESC") # SELECT * FROM clients ORDER BY orders_count ASC, created_at DESC ``` +WARNING: If you are using **MySQL 5.7.5** and above, then on selecting fields from a result set using methods like `select`, `pluck` and `ids`; the `order` method will raise an `ActiveRecord::StatementInvalid` exception unless the field(s) used in `order` clause are included in the select list. See the next section for selecting fields from the result set. Selecting Specific Fields ------------------------- @@ -617,9 +694,9 @@ SELECT * FROM clients LIMIT 5 OFFSET 30 Group ----- -To apply a `GROUP BY` clause to the SQL fired by the finder, you can specify the `group` method on the find. +To apply a `GROUP BY` clause to the SQL fired by the finder, you can use the `group` method. -For example, if you want to find a collection of the dates orders were created on: +For example, if you want to find a collection of the dates on which orders were created: ```ruby Order.select("date(created_at) as ordered_date, sum(price) as total_price").group("date(created_at)") @@ -637,7 +714,7 @@ 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`. +To get the total of grouped items on a single query, call `count` after the `group`. ```ruby Order.group(:status).count @@ -655,7 +732,7 @@ GROUP BY status Having ------ -SQL uses the `HAVING` clause to specify conditions on the `GROUP BY` fields. You can add the `HAVING` clause to the SQL fired by the `Model.find` by adding the `:having` option to the find. +SQL uses the `HAVING` clause to specify conditions on the `GROUP BY` fields. You can add the `HAVING` clause to the SQL fired by the `Model.find` by adding the `having` method to the find. For example: @@ -673,7 +750,7 @@ GROUP BY date(created_at) HAVING sum(price) > 100 ``` -This will return single order objects for each day, but only those that are ordered more than $100 in a day. +This returns the date and total price for each order object, grouped by the day they were ordered and where the price is more than $100. Overriding Conditions --------------------- @@ -703,8 +780,7 @@ 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: +A relation which has used `unscope` will affect any relation into which it is merged: ```ruby Article.order('id asc').merge(Article.unscope(:order)) @@ -725,7 +801,7 @@ The SQL that would be executed: 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 +SELECT * FROM articles WHERE id > 10 ORDER BY id DESC LIMIT 20 ``` @@ -734,7 +810,7 @@ SELECT "articles".* FROM "articles" WHERE (id > 10) ORDER BY id desc LIMIT 20 The `reorder` method overrides the default scope order. For example: ```ruby -class Article < ActiveRecord::Base +class Article < ApplicationRecord has_many :comments, -> { order('posted_at DESC') } end @@ -744,14 +820,14 @@ Article.find(10).comments.reorder('name') The SQL that would be executed: ```sql -SELECT * FROM articles WHERE id = 10 +SELECT * FROM articles WHERE id = 10 LIMIT 1 SELECT * FROM comments WHERE article_id = 10 ORDER BY name ``` -In case the `reorder` clause is not used, the SQL executed would be: +In the case where the `reorder` clause is not used, the SQL executed would be: ```sql -SELECT * FROM articles WHERE id = 10 +SELECT * FROM articles WHERE id = 10 LIMIT 1 SELECT * FROM comments WHERE article_id = 10 ORDER BY posted_at DESC ``` @@ -837,7 +913,7 @@ end Readonly Objects ---------------- -Active Record provides `readonly` method on a relation to explicitly disallow modification of any of the returned objects. Any attempt to alter a readonly record will not succeed, raising an `ActiveRecord::ReadOnlyRecord` exception. +Active Record provides the `readonly` method on a relation to explicitly disallow modification of any of the returned objects. Any attempt to alter a readonly record will not succeed, raising an `ActiveRecord::ReadOnlyRecord` exception. ```ruby client = Client.readonly.first @@ -883,7 +959,7 @@ This behavior can be turned off by setting `ActiveRecord::Base.lock_optimistical To override the name of the `lock_version` column, `ActiveRecord::Base` provides a class attribute called `locking_column`: ```ruby -class Client < ActiveRecord::Base +class Client < ApplicationRecord self.locking_column = :lock_client_column end ``` @@ -898,7 +974,7 @@ For example: Item.transaction do i = Item.lock.first i.name = 'Jones' - i.save + i.save! end ``` @@ -934,58 +1010,63 @@ end Joining Tables -------------- -Active Record provides a finder method called `joins` for specifying `JOIN` clauses on the resulting SQL. There are multiple ways to use the `joins` method. +Active Record provides two finder methods for specifying `JOIN` clauses on the +resulting SQL: `joins` and `left_outer_joins`. +While `joins` should be used for `INNER JOIN` or custom queries, +`left_outer_joins` is used for queries using `LEFT OUTER JOIN`. -### Using a String SQL Fragment +### `joins` + +There are multiple ways to use the `joins` method. + +#### Using a String SQL Fragment You can just supply the raw SQL specifying the `JOIN` clause to `joins`: ```ruby -Client.joins('LEFT OUTER JOIN addresses ON addresses.client_id = clients.id') +Author.joins("INNER JOIN posts ON posts.author_id = authors.id AND posts.published = 't'") ``` This will result in the following SQL: ```sql -SELECT clients.* FROM clients LEFT OUTER JOIN addresses ON addresses.client_id = clients.id +SELECT authors.* FROM authors INNER JOIN posts ON posts.author_id = authors.id AND posts.published = 't' ``` -### Using Array/Hash of Named Associations - -WARNING: This method only works with `INNER JOIN`. +#### Using Array/Hash of Named Associations 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`, `Article`, `Comment`, `Guest` and `Tag` models: ```ruby -class Category < ActiveRecord::Base +class Category < ApplicationRecord has_many :articles end -class Article < ActiveRecord::Base +class Article < ApplicationRecord belongs_to :category has_many :comments has_many :tags end -class Comment < ActiveRecord::Base +class Comment < ApplicationRecord belongs_to :article has_one :guest end -class Guest < ActiveRecord::Base +class Guest < ApplicationRecord belongs_to :comment end -class Tag < ActiveRecord::Base +class Tag < ApplicationRecord belongs_to :article end ``` Now all of the following will produce the expected join queries using `INNER JOIN`: -#### Joining a Single Association +##### Joining a Single Association ```ruby Category.joins(:articles) @@ -998,7 +1079,7 @@ SELECT categories.* FROM categories INNER JOIN articles ON articles.category_id = 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`. +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).distinct`. #### Joining Multiple Associations @@ -1010,13 +1091,13 @@ This produces: ```sql SELECT articles.* FROM articles - INNER JOIN categories ON articles.category_id = categories.id + INNER JOIN categories ON categories.id = articles.category_id INNER JOIN comments ON comments.article_id = articles.id ``` 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) +##### Joining Nested Associations (Single Level) ```ruby Article.joins(comments: :guest) @@ -1032,7 +1113,7 @@ SELECT articles.* FROM articles Or, in English: "return all articles that have a comment made by a guest." -#### Joining Nested Associations (Multiple Level) +##### Joining Nested Associations (Multiple Level) ```ruby Category.joins(articles: [{ comments: :guest }, :tags]) @@ -1048,9 +1129,11 @@ SELECT categories.* FROM categories INNER JOIN tags ON tags.article_id = articles.id ``` -### Specifying Conditions on the Joined Tables +Or, in English: "return all categories that have articles, where those articles have a comment made by a guest, and where those articles also have a tag." -You can specify conditions on the joined tables using the regular [Array](#array-conditions) and [String](#pure-string-conditions) conditions. [Hash conditions](#hash-conditions) provides a special syntax for specifying conditions for the joined tables: +#### Specifying Conditions on the Joined Tables + +You can specify conditions on the joined tables using the regular [Array](#array-conditions) and [String](#pure-string-conditions) conditions. [Hash conditions](#hash-conditions) provide a special syntax for specifying conditions for the joined tables: ```ruby time_range = (Time.now.midnight - 1.day)..Time.now.midnight @@ -1066,6 +1149,26 @@ 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. +### `left_outer_joins` + +If you want to select a set of records whether or not they have associated +records you can use the `left_outer_joins` method. + +```ruby +Author.left_outer_joins(:posts).distinct.select('authors.*, COUNT(posts.*) AS posts_count').group('authors.id') +``` + +Which produces: + +```sql +SELECT DISTINCT authors.*, COUNT(posts.*) AS posts_count FROM "authors" +LEFT OUTER JOIN posts ON posts.author_id = authors.id GROUP BY authors.id +``` + +Which means: "return all authors with their count of posts, whether or not they +have any posts at all" + + Eager Loading Associations -------------------------- @@ -1089,7 +1192,7 @@ This code looks fine at the first sight. But the problem lies within the total n Active Record lets you specify in advance all the associations that are going to be loaded. This is possible by specifying the `includes` method of the `Model.find` call. With `includes`, Active Record ensures that all of the specified associations are loaded using the minimum possible number of queries. -Revisiting the above case, we could rewrite `Client.limit(10)` to use eager load addresses: +Revisiting the above case, we could rewrite `Client.limit(10)` to eager load addresses: ```ruby clients = Client.includes(:address).limit(10) @@ -1158,7 +1261,8 @@ 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. - +NOTE: If an association is eager loaded as part of a join, any fields from a custom select clause will not present be on the loaded models. +This is because it is ambiguous whether they should appear on the parent record, or the child. Scopes ------ @@ -1168,7 +1272,7 @@ 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 Article < ActiveRecord::Base +class Article < ApplicationRecord scope :published, -> { where(published: true) } end ``` @@ -1176,7 +1280,7 @@ end This is exactly the same as defining a class method, and which you use is a matter of personal preference: ```ruby -class Article < ActiveRecord::Base +class Article < ApplicationRecord def self.published where(published: true) end @@ -1186,7 +1290,7 @@ end Scopes are also chainable within scopes: ```ruby -class Article < ActiveRecord::Base +class Article < ApplicationRecord scope :published, -> { where(published: true) } scope :published_and_commented, -> { published.where("comments_count > 0") } end @@ -1210,7 +1314,7 @@ category.articles.published # => [published articles belonging to this category] Your scope can take arguments: ```ruby -class Article < ActiveRecord::Base +class Article < ApplicationRecord scope :created_before, ->(time) { where("created_at < ?", time) } end ``` @@ -1224,7 +1328,7 @@ 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 Article < ActiveRecord::Base +class Article < ApplicationRecord def self.created_before(time) where("created_at < ?", time) end @@ -1237,13 +1341,35 @@ Using a class method is the preferred way to accept arguments for scopes. These category.articles.created_before(time) ``` +### Using conditionals + +Your scope can utilize conditionals: + +```ruby +class Article < ApplicationRecord + scope :created_before, ->(time) { where("created_at < ?", time) if time.present? } +end +``` + +Like the other examples, this will behave similarly to a class method. + +```ruby +class Article < ApplicationRecord + def self.created_before(time) + where("created_at < ?", time) if time.present? + end +end +``` + +However, there is one important caveat: A scope will always return an `ActiveRecord::Relation` object, even if the conditional evaluates to `false`, whereas a class method, will return `nil`. This can cause `NoMethodError` when chaining class methods with conditionals, if any of the conditionals return `false`. + ### Applying a default scope If we wish for a scope to be applied across all queries to the model we can use the `default_scope` method within the model itself. ```ruby -class Client < ActiveRecord::Base +class Client < ApplicationRecord default_scope { where("removed_at IS NULL") } end ``` @@ -1259,19 +1385,43 @@ If you need to do more complex things with a default scope, you can alternativel define it as a class method: ```ruby -class Client < ActiveRecord::Base +class Client < ApplicationRecord def self.default_scope # Should return an ActiveRecord::Relation. end end ``` +NOTE: The `default_scope` is also applied while creating/building a record +when the scope arguments are given as a `Hash`. It is not applied while +updating a record. E.g.: + +```ruby +class Client < ApplicationRecord + default_scope { where(active: true) } +end + +Client.new # => #<Client id: nil, active: true> +Client.unscoped.new # => #<Client id: nil, active: nil> +``` + +Be aware that, when given in the `Array` format, `default_scope` query arguments +cannot be converted to a `Hash` for default attribute assignment. E.g.: + +```ruby +class Client < ApplicationRecord + default_scope { where("active = ?", true) } +end + +Client.new # => #<Client id: nil, active: nil> +``` + ### Merging of scopes Just like `where` clauses scopes are merged using `AND` conditions. ```ruby -class User < ActiveRecord::Base +class User < ApplicationRecord scope :active, -> { where state: 'active' } scope :inactive, -> { where state: 'inactive' } end @@ -1300,7 +1450,7 @@ One important caveat is that `default_scope` will be prepended in `scope` and `where` conditions. ```ruby -class User < ActiveRecord::Base +class User < ApplicationRecord default_scope { where state: 'pending' } scope :active, -> { where state: 'active' } scope :inactive, -> { where state: 'inactive' } @@ -1331,8 +1481,15 @@ Client.unscoped.load This method removes all scoping and will do a normal query on the table. -Note that chaining `unscoped` with a `scope` does not work. In these cases, it is -recommended that you use the block form of `unscoped`: +```ruby +Client.unscoped.all +# SELECT "clients".* FROM "clients" + +Client.where(published: false).unscoped.all +# SELECT "clients".* FROM "clients" +``` + +`unscoped` can also accept a block. ```ruby Client.unscoped { @@ -1343,16 +1500,46 @@ Client.unscoped { 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` for free from Active Record. If you have a `locked` field on the `Client` model, you also get `find_by_locked` and methods. +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` method. 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)`. +Enums +----- + +The `enum` macro maps an integer column to a set of possible values. + +```ruby +class Book < ApplicationRecord + enum availability: [:available, :unavailable] +end +``` + +This will automatically create the corresponding [scopes](#scopes) to query the +model. Methods to transition between states and query the current state are also +added. + +```ruby +# Both examples below query just available books. +Book.available +# or +Book.where(availability: :available) + +book = Book.new(availability: :available) +book.available? # => true +book.unavailable! # => true +book.available? # => false +``` + +Read the full documentation about enums +[in the Rails API docs](http://api.rubyonrails.org/classes/ActiveRecord/Enum.html). + Understanding The Method Chaining --------------------------------- -The Active Record pattern implements [Method Chaining](http://en.wikipedia.org/wiki/Method_chaining), +The Active Record pattern implements [Method Chaining](https://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 @@ -1380,7 +1567,7 @@ 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' +WHERE comments.created_at > '2015-01-01' ``` ### Retrieving specific data from multiple tables @@ -1414,7 +1601,7 @@ It's common that you need to find a record or create it if it doesn't exist. You ### `find_or_create_by` -The `find_or_create_by` method checks whether a record with the attributes exists. If it doesn't, then `create` is called. Let's see an example. +The `find_or_create_by` method checks whether a record with the specified attributes exists. If it doesn't, then `create` is called. Let's see an example. Suppose you want to find a client named 'Andy', and if there's none, create one. You can do so by running: @@ -1483,7 +1670,7 @@ now want the client named 'Nick': ```ruby nick = Client.find_or_initialize_by(first_name: 'Nick') -# => <Client id: nil, first_name: "Nick", orders_count: 0, locked: true, created_at: "2011-08-30 06:09:27", updated_at: "2011-08-30 06:09:27"> +# => #<Client id: nil, first_name: "Nick", orders_count: 0, locked: true, created_at: "2011-08-30 06:09:27", updated_at: "2011-08-30 06:09:27"> nick.persisted? # => false @@ -1515,24 +1702,24 @@ Client.find_by_sql("SELECT * FROM clients INNER JOIN orders ON clients.id = orders.client_id ORDER BY clients.created_at desc") # => [ - #<Client id: 1, first_name: "Lucas" >, - #<Client id: 2, first_name: "Jan" >, - # ... -] +# #<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. ### `select_all` -`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. +`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. This method will return an instance of `ActiveRecord::Result` class and calling `to_hash` on this object would return you an array of hashes where each hash indicates a record. ```ruby -Client.connection.select_all("SELECT first_name, created_at FROM clients WHERE id = '1'") +Client.connection.select_all("SELECT first_name, created_at FROM clients WHERE id = '1'").to_hash # => [ - {"first_name"=>"Rafael", "created_at"=>"2012-11-10 23:23:45.281189"}, - {"first_name"=>"Eileen", "created_at"=>"2013-12-09 11:22:35.221282"} -] +# {"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` @@ -1577,7 +1764,7 @@ a large or often-running query. However, any model method overrides will not be available. For example: ```ruby -class Client < ActiveRecord::Base +class Client < ApplicationRecord def name "I am #{super}" end @@ -1612,7 +1799,7 @@ Person.ids ``` ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord self.primary_key = "person_id" end @@ -1684,14 +1871,14 @@ All calculation methods work directly on a model: ```ruby Client.count -# SELECT count(*) AS count_all FROM clients +# SELECT COUNT(*) FROM clients ``` Or on a relation: ```ruby Client.where(first_name: 'Ryan').count -# SELECT count(*) AS count_all FROM clients WHERE (first_name = 'Ryan') +# SELECT COUNT(*) FROM clients WHERE (first_name = 'Ryan') ``` You can also use various finder methods on a relation for performing complex calculations: @@ -1703,9 +1890,9 @@ Client.includes("orders").where(first_name: 'Ryan', orders: { status: 'received' Which will execute: ```sql -SELECT count(DISTINCT clients.id) AS count_all FROM clients - LEFT OUTER JOIN orders ON orders.client_id = client.id WHERE - (clients.first_name = 'Ryan' AND orders.status = 'received') +SELECT COUNT(DISTINCT clients.id) FROM clients + LEFT OUTER JOIN orders ON orders.client_id = clients.id + WHERE (clients.first_name = 'Ryan' AND orders.status = 'received') ``` ### Count @@ -1785,10 +1972,11 @@ EXPLAIN for: SELECT `users`.* FROM `users` INNER JOIN `articles` ON `articles`.` 2 rows in set (0.00 sec) ``` -under MySQL. +under MySQL and MariaDB. -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 +Active Record performs a pretty printing that emulates that of the +corresponding database shell. So, the same query running with the +PostgreSQL adapter would yield instead ``` EXPLAIN for: SELECT "users".* FROM "users" INNER JOIN "articles" ON "articles"."user_id" = "users"."id" WHERE "users"."id" = 1 @@ -1844,7 +2032,7 @@ EXPLAIN for: SELECT `articles`.* FROM `articles` WHERE `articles`.`user_id` IN 1 row in set (0.00 sec) ``` -under MySQL. +under MySQL and MariaDB. ### Interpreting EXPLAIN @@ -1853,6 +2041,8 @@ following pointers may be helpful: * SQLite3: [EXPLAIN QUERY PLAN](http://www.sqlite.org/eqp.html) -* MySQL: [EXPLAIN Output Format](http://dev.mysql.com/doc/refman/5.6/en/explain-output.html) +* MySQL: [EXPLAIN Output Format](http://dev.mysql.com/doc/refman/5.7/en/explain-output.html) + +* MariaDB: [EXPLAIN](https://mariadb.com/kb/en/mariadb/explain/) -* PostgreSQL: [Using EXPLAIN](http://www.postgresql.org/docs/current/static/using-explain.html) +* PostgreSQL: [Using EXPLAIN](https://www.postgresql.org/docs/current/static/using-explain.html) diff --git a/guides/source/active_record_validations.md b/guides/source/active_record_validations.md index d251c5c0b1..e9157f3db1 100644 --- a/guides/source/active_record_validations.md +++ b/guides/source/active_record_validations.md @@ -20,7 +20,7 @@ Validations Overview Here's an example of a very simple validation: ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, presence: true end @@ -47,7 +47,7 @@ built-in helpers for common needs, and allows you to create your own validation methods as well. There are several other ways to validate data before it is saved into your -database, including native database constraints, client-side validations, +database, including native database constraints, client-side validations and controller-level validations. Here's a summary of the pros and cons: * Database constraints and/or stored procedures make the validation mechanisms @@ -80,7 +80,7 @@ method to determine whether an object is already in the database or not. Consider the following simple Active Record class: ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord end ``` @@ -122,7 +122,7 @@ database only if the object is valid: * `update!` The bang versions (e.g. `save!`) raise an exception if the record is invalid. -The non-bang versions don't, `save` and `update` return `false`, +The non-bang versions don't: `save` and `update` return `false`, and `create` just returns the object. ### Skipping Validations @@ -143,19 +143,21 @@ database regardless of its validity. They should be used with caution. * `update_counters` Note that `save` also has the ability to skip validations if passed `validate: -false` as argument. This technique should be used with caution. +false` as an argument. This technique should be used with caution. * `save(validate: false)` ### `valid?` and `invalid?` -To verify whether or not an object is valid, Rails uses the `valid?` method. -You can also use this method on your own. `valid?` triggers your validations +Before saving an Active Record object, Rails runs your validations. +If these validations produce any errors, Rails does not save the object. + +You can also run these validations on your own. `valid?` triggers your validations and returns true if no errors were found in the object, and false otherwise. As you saw above: ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, presence: true end @@ -168,11 +170,12 @@ through the `errors.messages` instance method, which returns a collection of err 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 -technically invalid, because validations are not run when using `new`. +Note that an object instantiated with `new` will not report errors +even if it's technically invalid, because validations are automatically run +only when the object is saved, such as with the `create` or `save` methods. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, presence: true end @@ -218,7 +221,7 @@ it doesn't verify the validity of the object as a whole. It only checks to see whether there are errors found on an individual attribute of the object. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, presence: true end @@ -236,13 +239,13 @@ To check which validations failed on an invalid attribute, you can use key to get the symbol of the validator: ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, presence: true end >> person = Person.new >> person.valid? ->> person.errors.details[:name] #=> [{error: :blank}] +>> person.errors.details[:name] # => [{error: :blank}] ``` Using `details` with custom validators is covered in the [Working with @@ -272,28 +275,42 @@ available helpers. This method validates that a checkbox on the user interface was checked when a form was submitted. This is typically used when the user needs to agree to your -application's terms of service, confirm reading some text, or any similar -concept. This validation is very specific to web applications and this -'acceptance' does not need to be recorded anywhere in your database (if you -don't have a field for it, the helper will just create a virtual attribute). +application's terms of service, confirm that some text is read, or any similar +concept. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :terms_of_service, acceptance: true end ``` +This check is performed only if `terms_of_service` is not `nil`. The default error message for this helper is _"must be accepted"_. +You can also pass custom message via the `message` option. + +```ruby +class Person < ApplicationRecord + validates :terms_of_service, acceptance: { message: 'must be abided' } +end +``` -It can receive an `:accept` option, which determines the value that will be -considered acceptance. It defaults to "1" and can be easily changed. +It can also receive an `:accept` option, which determines the allowed values +that will be considered as accepted. It defaults to `['1', true]` and can be +easily changed. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :terms_of_service, acceptance: { accept: 'yes' } + validates :eula, acceptance: { accept: ['TRUE', 'accepted'] } end ``` +This validation is very specific to web applications and this +'acceptance' does not need to be recorded anywhere in your database. If you +don't have a field for it, the helper will just create a virtual attribute. If +the field does exist in your database, the `accept` option must be set to +or include `true` or else the validation will not run. + ### `validates_associated` You should use this helper when your model has associations with other models @@ -301,7 +318,7 @@ and they also need to be validated. When you try to save your object, `valid?` will be called upon each one of the associated objects. ```ruby -class Library < ActiveRecord::Base +class Library < ApplicationRecord has_many :books validates_associated :books end @@ -324,7 +341,7 @@ or a password. This validation creates a virtual attribute whose name is the name of the field that has to be confirmed with "_confirmation" appended. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :email, confirmation: true end ``` @@ -338,15 +355,25 @@ In your view template you could use something like This check is performed only if `email_confirmation` is not `nil`. To require confirmation, make sure to add a presence check for the confirmation attribute -(we'll take a look at `presence` later on this guide): +(we'll take a look at `presence` later on in this guide): ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :email, confirmation: true validates :email_confirmation, presence: true end ``` +There is also a `:case_sensitive` option that you can use to define whether the +confirmation constraint will be case sensitive or not. This option defaults to +true. + +```ruby +class Person < ApplicationRecord + validates :email, confirmation: { case_sensitive: false } +end +``` + The default error message for this helper is _"doesn't match confirmation"_. ### `exclusion` @@ -355,7 +382,7 @@ This helper validates that the attributes' values are not included in a given set. In fact, this set can be any enumerable object. ```ruby -class Account < ActiveRecord::Base +class Account < ApplicationRecord validates :subdomain, exclusion: { in: %w(www us ca jp), message: "%{value} is reserved." } end @@ -365,7 +392,8 @@ The `exclusion` helper has an option `:in` that receives the set of values that will not be accepted for the validated attributes. The `:in` option has an alias called `:within` that you can use for the same purpose, if you'd like to. This example uses the `:message` option to show how you can include the -attribute's value. +attribute's value. For full options to the message argument please see the +[message documentation](#message). The default error message is _"is reserved"_. @@ -375,7 +403,7 @@ This helper validates the attributes' values by testing whether they match a given regular expression, which is specified using the `:with` option. ```ruby -class Product < ActiveRecord::Base +class Product < ApplicationRecord validates :legacy_code, format: { with: /\A[a-zA-Z]+\z/, message: "only allows letters" } end @@ -391,7 +419,7 @@ This helper validates that the attributes' values are included in a given set. In fact, this set can be any enumerable object. ```ruby -class Coffee < ActiveRecord::Base +class Coffee < ApplicationRecord validates :size, inclusion: { in: %w(small medium large), message: "%{value} is not a valid size" } end @@ -400,7 +428,8 @@ end The `inclusion` helper has an option `:in` that receives the set of values that will be accepted. The `:in` option has an alias called `:within` that you can use for the same purpose, if you'd like to. The previous example uses the -`:message` option to show how you can include the attribute's value. +`:message` option to show how you can include the attribute's value. For full +options please see the [message documentation](#message). The default error message for this helper is _"is not included in the list"_. @@ -410,7 +439,7 @@ This helper validates the length of the attributes' values. It provides a variety of options, so you can specify length constraints in different ways: ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, length: { minimum: 2 } validates :bio, length: { maximum: 500 } validates :password, length: { in: 6..20 } @@ -433,27 +462,12 @@ number corresponding to the length constraint being used. You can still use the `:message` option to specify an error message. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :bio, length: { maximum: 1000, too_long: "%{count} characters is the maximum allowed" } end ``` -This helper counts characters by default, but you can split the value in a -different way using the `:tokenizer` option: - -```ruby -class Essay < ActiveRecord::Base - validates :content, length: { - minimum: 300, - maximum: 400, - tokenizer: lambda { |str| str.split(/\s+/) }, - too_short: "must have at least %{count} words", - too_long: "must have at most %{count} words" - } -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 `presence: true` instead. When @@ -476,11 +490,8 @@ If you set `:only_integer` to `true`, then it will use the regular expression to validate the attribute's value. Otherwise, it will try to convert the value to a number using `Float`. -WARNING. Note that the regular expression above allows a trailing newline -character. - ```ruby -class Player < ActiveRecord::Base +class Player < ApplicationRecord validates :points, numericality: true validates :games_played, numericality: { only_integer: true } end @@ -499,9 +510,11 @@ constraints to acceptable values: default error message for this option is _"must be equal to %{count}"_. * `:less_than` - Specifies the value must be less than the supplied value. The default error message for this option is _"must be less than %{count}"_. -* `:less_than_or_equal_to` - Specifies the value must be less than or equal the - supplied value. The default error message for this option is _"must be less - than or equal to %{count}"_. +* `:less_than_or_equal_to` - Specifies the value must be less than or equal to + the supplied value. The default error message for this option is _"must be + less than or equal to %{count}"_. +* `:other_than` - Specifies the value must be other than the supplied value. + The default error message for this option is _"must be other than %{count}"_. * `:odd` - Specifies the value must be an odd number if set to true. The default error message for this option is _"must be odd"_. * `:even` - Specifies the value must be an even number if set to true. The @@ -518,7 +531,7 @@ This helper validates that the specified attributes are not empty. It uses the is, a string that is either empty or consists of whitespace. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, :login, :email, presence: true end ``` @@ -528,7 +541,7 @@ whether the associated object itself is present, and not the foreign key used to map the association. ```ruby -class LineItem < ActiveRecord::Base +class LineItem < ApplicationRecord belongs_to :order validates :order, presence: true end @@ -538,7 +551,7 @@ In order to validate associated records whose presence is required, you must specify the `:inverse_of` option for the association: ```ruby -class Order < ActiveRecord::Base +class Order < ApplicationRecord has_many :line_items, inverse_of: :order end ``` @@ -551,7 +564,6 @@ Since `false.blank?` is true, if you want to validate the presence of a boolean 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] } ``` @@ -566,7 +578,7 @@ This helper validates that the specified attributes are absent. It uses the is, a string that is either empty or consists of whitespace. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, :login, :email, absence: true end ``` @@ -576,7 +588,7 @@ whether the associated object itself is absent, and not the foreign key used to map the association. ```ruby -class LineItem < ActiveRecord::Base +class LineItem < ApplicationRecord belongs_to :order validates :order, absence: true end @@ -586,7 +598,7 @@ 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 +class Order < ApplicationRecord has_many :line_items, inverse_of: :order end ``` @@ -609,7 +621,7 @@ with the same value for a column that you intend to be unique. To avoid that, you must create a unique index on that column in your database. ```ruby -class Account < ActiveRecord::Base +class Account < ApplicationRecord validates :email, uniqueness: true end ``` @@ -617,23 +629,23 @@ end The validation happens by performing an SQL query into the model's table, searching for an existing record with the same value in that attribute. -There is a `:scope` option that you can use to specify other attributes that +There is a `:scope` option that you can use to specify one or more attributes that are used to limit the uniqueness check: ```ruby -class Holiday < ActiveRecord::Base +class Holiday < ApplicationRecord validates :name, uniqueness: { scope: :year, message: "should happen once per year" } end ``` -Should you wish to create a database constraint to prevent possible violations of a uniqueness validation using the `:scope` option, 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 or [the PostgreSQL manual](http://www.postgresql.org/docs/9.4/static/ddl-constraints.html) for examples of unique constraints that refer to a group of columns. +Should you wish to create a database constraint to prevent possible violations of a uniqueness validation using the `:scope` option, you must create a unique index on both columns in your database. See [the MySQL manual](http://dev.mysql.com/doc/refman/5.7/en/multiple-column-indexes.html) for more details about multiple column indexes or [the PostgreSQL manual](https://www.postgresql.org/docs/current/static/ddl-constraints.html) for examples of unique constraints that refer to a group of columns. There is also a `:case_sensitive` option that you can use to define whether the uniqueness constraint will be case sensitive or not. This option defaults to true. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, uniqueness: { case_sensitive: false } end ``` @@ -656,7 +668,7 @@ class GoodnessValidator < ActiveModel::Validator end end -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates_with GoodnessValidator end ``` @@ -684,7 +696,7 @@ class GoodnessValidator < ActiveModel::Validator end end -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates_with GoodnessValidator, fields: [:first_name, :last_name] end ``` @@ -697,7 +709,7 @@ 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 +class Person < ApplicationRecord validate do |person| GoodnessValidator.new(person).validate end @@ -726,7 +738,7 @@ passed to `validates_each` will be tested against it. In the following example, we don't want names and surnames to begin with lower case. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates_each :name, :surname do |record, attr, value| record.errors.add(attr, 'must start with upper case') if value =~ /\A[[:lower:]]/ end @@ -749,12 +761,15 @@ The `:allow_nil` option skips the validation when the value being validated is `nil`. ```ruby -class Coffee < ActiveRecord::Base +class Coffee < ApplicationRecord validates :size, inclusion: { in: %w(small medium large), message: "%{value} is not a valid size" }, allow_nil: true end ``` +For full options to the message argument please see the +[message documentation](#message). + ### `:allow_blank` The `:allow_blank` option is similar to the `:allow_nil` option. This option @@ -762,7 +777,7 @@ will let validation pass if the attribute's value is `blank?`, like `nil` or an empty string for example. ```ruby -class Topic < ActiveRecord::Base +class Topic < ApplicationRecord validates :title, length: { is: 5 }, allow_blank: true end @@ -775,7 +790,37 @@ Topic.create(title: nil).valid? # => true As you've already seen, the `:message` option lets you specify the message that will be added to the `errors` collection when validation fails. When this option is not used, Active Record will use the respective default error message -for each validation helper. +for each validation helper. The `:message` option accepts a `String` or `Proc`. + +A `String` `:message` value can optionally contain any/all of `%{value}`, +`%{attribute}`, and `%{model}` which will be dynamically replaced when +validation fails. This replacement is done using the I18n gem, and the +placeholders must match exactly, no spaces are allowed. + +A `Proc` `:message` value is given two arguments: the object being validated, and +a hash with `:model`, `:attribute`, and `:value` key-value pairs. + +```ruby +class Person < ApplicationRecord + # Hard-coded message + validates :name, presence: { message: "must be given please" } + + # Message with dynamic attribute value. %{value} will be replaced with + # the actual value of the attribute. %{attribute} and %{model} also + # available. + validates :age, numericality: { message: "%{value} seems wrong" } + + # Proc + validates :username, + uniqueness: { + # object = person object being validated + # data = { model: "Person", attribute: "Username", value: <username> } + message: ->(object, data) do + "Hey #{object.name}!, #{data[:value]} is taken already! Try again #{Time.zone.tomorrow}" + end + } +end +``` ### `:on` @@ -787,7 +832,7 @@ new record is created or `on: :update` to run the validation only when a record is updated. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord # it will be possible to update email with a duplicated value validates :email, uniqueness: true, on: :create @@ -799,6 +844,25 @@ class Person < ActiveRecord::Base end ``` +You can also use `on:` to define custom context. +Custom contexts need to be triggered explicitly +by passing name of the context to `valid?`, `invalid?` or `save`. + +```ruby +class Person < ApplicationRecord + validates :email, uniqueness: true, on: :account_setup + validates :age, numericality: true, on: :account_setup +end + +person = Person.new +``` + +`person.valid?(:account_setup)` executes both the validations +without saving the model. And `person.save(context: :account_setup)` +validates `person` in `account_setup` context before saving. +On explicit triggers, model is validated by +validations of only that context and validations without context. + Strict Validations ------------------ @@ -806,17 +870,17 @@ You can also specify validations to be strict and raise `ActiveModel::StrictValidationFailed` when the object is invalid. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, presence: { strict: true } 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 the ability to pass a custom exception to the `:strict` option. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :token, presence: true, uniqueness: true, strict: TokenGenerationException end @@ -828,7 +892,7 @@ Conditional Validation Sometimes it will make sense to validate an object only when a given predicate is satisfied. You can do that by using the `:if` and `:unless` options, which -can take a symbol, a string, a `Proc` or an `Array`. You may use the `:if` +can take a symbol, a `Proc` or an `Array`. You may use the `:if` option when you want to specify when the validation **should** happen. If you want to specify when the validation **should not** happen, then you may use the `:unless` option. @@ -840,7 +904,7 @@ to the name of a method that will get called right before validation happens. This is the most commonly used option. ```ruby -class Order < ActiveRecord::Base +class Order < ApplicationRecord validates :card_number, presence: true, if: :paid_with_card? def paid_with_card? @@ -849,18 +913,6 @@ class Order < ActiveRecord::Base end ``` -### Using a String with `:if` and `:unless` - -You can also use a string that will be evaluated using `eval` and needs to -contain valid Ruby code. You should use this option only when the string -represents a really short condition. - -```ruby -class Person < ActiveRecord::Base - validates :surname, presence: true, if: "name.nil?" -end -``` - ### Using a Proc with `:if` and `:unless` Finally, it's possible to associate `:if` and `:unless` with a `Proc` object @@ -869,7 +921,7 @@ inline condition instead of a separate method. This option is best suited for one-liners. ```ruby -class Account < ActiveRecord::Base +class Account < ApplicationRecord validates :password, confirmation: true, unless: Proc.new { |a| a.password.blank? } end @@ -877,11 +929,11 @@ end ### Grouping Conditional validations -Sometimes it is useful to have multiple validations use one condition, it can +Sometimes it is useful to have multiple validations use one condition. It can be easily achieved using `with_options`. ```ruby -class User < ActiveRecord::Base +class User < ApplicationRecord with_options if: :is_admin? do |admin| admin.validates :password, length: { minimum: 10 } admin.validates :email, presence: true @@ -889,8 +941,8 @@ class User < ActiveRecord::Base end ``` -All validations inside of `with_options` block will have automatically passed -the condition `if: :is_admin?` +All validations inside of the `with_options` block will have automatically +passed the condition `if: :is_admin?` ### Combining Validation Conditions @@ -899,9 +951,9 @@ should happen, an `Array` can be used. Moreover, you can apply both `:if` and `:unless` to the same validation. ```ruby -class Computer < ActiveRecord::Base +class Computer < ApplicationRecord validates :mouse, presence: true, - if: ["market.retail?", :desktop?], + if: [Proc.new { |c| c.market.retail? }, :desktop?], unless: Proc.new { |c| c.trackpad.present? } end ``` @@ -953,7 +1005,7 @@ class EmailValidator < ActiveModel::EachValidator end end -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :email, presence: true, email: true end ``` @@ -965,14 +1017,19 @@ own custom validators. You can also create methods that verify the state of your models and add messages to the `errors` collection when they are invalid. You must then -register these methods by using the `validate` class method, passing in the -symbols for the validation methods' names. +register these methods by using the `validate` +([API](http://api.rubyonrails.org/classes/ActiveModel/Validations/ClassMethods.html#method-i-validate)) +class method, passing in the symbols for the validation methods' names. You can pass more than one symbol for each class method and the respective validations will be run in the same order as they were registered. +The `valid?` method will verify that the errors collection is empty, +so your custom validation methods should add errors to it when you +wish validation to fail: + ```ruby -class Invoice < ActiveRecord::Base +class Invoice < ApplicationRecord validate :expiration_date_cannot_be_in_the_past, :discount_cannot_be_greater_than_total_value @@ -990,12 +1047,13 @@ class Invoice < ActiveRecord::Base end ``` -By default such validations will run every time you call `valid?`. It is also -possible to control when to run these custom validations by giving an `:on` -option to the `validate` method, with either: `:create` or `:update`. +By default, such validations will run every time you call `valid?` +or save the object. But it is also possible to control when to run these +custom validations by giving an `:on` option to the `validate` method, +with either: `:create` or `:update`. ```ruby -class Invoice < ActiveRecord::Base +class Invoice < ApplicationRecord validate :active_customer, on: :create def active_customer @@ -1016,7 +1074,7 @@ The following is a list of the most commonly used methods. Please refer to the ` Returns an instance of the class `ActiveModel::Errors` containing all errors. Each key is the attribute name and the value is an array of strings with all errors. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, presence: true, length: { minimum: 3 } end @@ -1035,7 +1093,7 @@ person.errors.messages # => {} `errors[]` is used when you want to check the error messages for a specific attribute. It returns an array of strings with all error messages for the given attribute, each string with one error message. If there are no errors related to the attribute, it returns an empty array. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, presence: true, length: { minimum: 3 } end @@ -1060,7 +1118,7 @@ The `add` method lets you add an error message related to a particular attribute The `errors.full_messages` method (or its equivalent, `errors.to_a`) returns the error messages in a user-friendly format, with the capitalized attribute name prepended to each message, as shown in the examples below. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord def a_method_used_for_validation_purposes errors.add(:name, "cannot contain the characters !@#%*()_-+=") end @@ -1078,7 +1136,7 @@ person.errors.full_messages An equivalent to `errors#add` is to use `<<` to append a message to the `errors.messages` array for an attribute: ```ruby - class Person < ActiveRecord::Base + class Person < ApplicationRecord def a_method_used_for_validation_purposes errors.messages[:name] << "cannot contain the characters !@#%*()_-+=" end @@ -1099,7 +1157,7 @@ You can specify a validator type to the returned error details hash using the `errors.add` method. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord def a_method_used_for_validation_purposes errors.add(:name, :invalid_characters) end @@ -1115,7 +1173,7 @@ To improve the error details to contain the unallowed characters set for instanc you can pass additional keys to `errors.add`. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord def a_method_used_for_validation_purposes errors.add(:name, :invalid_characters, not_allowed: "!@#%*()_-+=") end @@ -1135,7 +1193,7 @@ validator type. You can add error messages that are related to the object's state as a whole, instead of being related to a specific attribute. You can use this method when you want to say that the object is invalid, no matter the values of its attributes. Since `errors[:base]` is an array, you can simply add a string to it and it will be used as an error message. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord def a_method_used_for_validation_purposes errors[:base] << "This person is invalid because ..." end @@ -1147,7 +1205,7 @@ end The `clear` method is used when you intentionally want to clear all the messages in the `errors` collection. Of course, calling `errors.clear` upon an invalid object won't actually make it valid: the `errors` collection will now be empty, but the next time you call `valid?` or any method that tries to save this object to the database, the validations will run again. If any of the validations fail, the `errors` collection will be filled again. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, presence: true, length: { minimum: 3 } end @@ -1159,9 +1217,9 @@ person.errors[:name] person.errors.clear person.errors.empty? # => true -p.save # => false +person.save # => false -p.errors[:name] +person.errors[:name] # => ["can't be blank", "is too short (minimum is 3 characters)"] ``` @@ -1170,7 +1228,7 @@ p.errors[:name] The `size` method returns the total number of error messages for the object. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, presence: true, length: { minimum: 3 } end diff --git a/guides/source/active_storage_overview.md b/guides/source/active_storage_overview.md new file mode 100644 index 0000000000..f45dbdee3e --- /dev/null +++ b/guides/source/active_storage_overview.md @@ -0,0 +1,556 @@ +**DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON http://guides.rubyonrails.org.** + +Active Storage Overview +======================= + +This guide covers how to attach files to your Active Record models. + +After reading this guide, you will know: + +* How to attach one or many files to a record. +* How to delete an attached file. +* How to link to an attached file. +* How to use variants to transform images. +* How to generate an image representation of a non-image file, such as a PDF or a video. +* How to send file uploads directly from browsers to a storage service, + bypassing your application servers. +* How to clean up files stored during testing. +* How to implement support for additional storage services. + +-------------------------------------------------------------------------------- + +What is Active Storage? +----------------------- + +Active Storage facilitates uploading files to a cloud storage service like +Amazon S3, Google Cloud Storage, or Microsoft Azure Storage and attaching those +files to Active Record objects. It comes with a local disk-based service for +development and testing and supports mirroring files to subordinate services for +backups and migrations. + +Using Active Storage, an application can transform image uploads with +[ImageMagick](https://www.imagemagick.org), generate image representations of +non-image uploads like PDFs and videos, and extract metadata from arbitrary +files. + +## Setup + +Active Storage uses two tables in your application’s database named +`active_storage_blobs` and `active_storage_attachments`. After upgrading your +application to Rails 5.2, run `rails active_storage:install` to generate a +migration that creates these tables. Use `rails db:migrate` to run the +migration. + +Declare Active Storage services in `config/storage.yml`. For each service your +application uses, provide a name and the requisite configuration. The example +below declares three services named `local`, `test`, and `amazon`: + +```yaml +local: + service: Disk + root: <%= Rails.root.join("storage") %> + +test: + service: Disk + root: <%= Rails.root.join("tmp/storage") %> + +amazon: + service: S3 + access_key_id: "" + secret_access_key: "" +``` + +Tell Active Storage which service to use by setting +`Rails.application.config.active_storage.service`. Because each environment will +likely use a different service, it is recommended to do this on a +per-environment basis. To use the disk service from the previous example in the +development environment, you would add the following to +`config/environments/development.rb`: + +```ruby +# Store files locally. +config.active_storage.service = :local +``` + +To use the Amazon S3 service in production, you add the following to +`config/environments/production.rb`: + +```ruby +# Store files on Amazon S3. +config.active_storage.service = :amazon +``` + +Continue reading for more information on the built-in service adapters (e.g. +`Disk` and `S3`) and the configuration they require. + +### Disk Service + +Declare a Disk service in `config/storage.yml`: + +```yaml +local: + service: Disk + root: <%= Rails.root.join("storage") %> +``` + +### Amazon S3 Service + +Declare an S3 service in `config/storage.yml`: + +```yaml +amazon: + service: S3 + access_key_id: "" + secret_access_key: "" + region: "" + bucket: "" +``` + +Add the [`aws-sdk-s3`](https://github.com/aws/aws-sdk-ruby) gem to your `Gemfile`: + +```ruby +gem "aws-sdk-s3", require: false +``` + +### Microsoft Azure Storage Service + +Declare an Azure Storage service in `config/storage.yml`: + +```yaml +azure: + service: AzureStorage + path: "" + storage_account_name: "" + storage_access_key: "" + container: "" +``` + +Add the [`azure-storage`](https://github.com/Azure/azure-storage-ruby) gem to your `Gemfile`: + +```ruby +gem "azure-storage", require: false +``` + +### Google Cloud Storage Service + +Declare a Google Cloud Storage service in `config/storage.yml`: + +```yaml +google: + service: GCS + credentials: <%= Rails.root.join("path/to/keyfile.json") %> + project: "" + bucket: "" +``` + +Optionally provide a Hash of credentials instead of a keyfile path: + +```yaml +google: + service: GCS + credentials: + type: "service_account" + project_id: "" + private_key_id: <%= Rails.application.credentials.dig(:gcs, :private_key_id) %> + private_key: <%= Rails.application.credentials.dig(:gcs, :private_key) %> + client_email: "" + client_id: "" + auth_uri: "https://accounts.google.com/o/oauth2/auth" + token_uri: "https://accounts.google.com/o/oauth2/token" + auth_provider_x509_cert_url: "https://www.googleapis.com/oauth2/v1/certs" + client_x509_cert_url: "" + project: "" + bucket: "" +``` + +Add the [`google-cloud-storage`](https://github.com/GoogleCloudPlatform/google-cloud-ruby/tree/master/google-cloud-storage) gem to your `Gemfile`: + +```ruby +gem "google-cloud-storage", "~> 1.3", require: false +``` + +### Mirror Service + +You can keep multiple services in sync by defining a mirror service. When a file +is uploaded or deleted, it's done across all the mirrored services. Mirrored +services can be used to facilitate a migration between services in production. +You can start mirroring to the new service, copy existing files from the old +service to the new, then go all-in on the new service. Define each of the +services you'd like to use as described above and reference them from a mirrored +service. + +```yaml +s3_west_coast: + service: S3 + access_key_id: "" + secret_access_key: "" + region: "" + bucket: "" + +s3_east_coast: + service: S3 + access_key_id: "" + secret_access_key: "" + region: "" + bucket: "" + +production: + service: Mirror + primary: s3_east_coast + mirrors: + - s3_west_coast +``` + +NOTE: Files are served from the primary service. + +Attaching Files to Records +-------------------------- + +### `has_one_attached` + +The `has_one_attached` macro sets up a one-to-one mapping between records and +files. Each record can have one file attached to it. + +For example, suppose your application has a `User` model. If you want each user to +have an avatar, define the `User` model like this: + +```ruby +class User < ApplicationRecord + has_one_attached :avatar +end +``` + +You can create a user with an avatar: + +```ruby +class SignupController < ApplicationController + def create + user = User.create!(user_params) + session[:user_id] = user.id + redirect_to root_path + end + + private + def user_params + params.require(:user).permit(:email_address, :password, :avatar) + end +end +``` + +Call `avatar.attach` to attach an avatar to an existing user: + +```ruby +Current.user.avatar.attach(params[:avatar]) +``` + +Call `avatar.attached?` to determine whether a particular user has an avatar: + +```ruby +Current.user.avatar.attached? +``` + +### `has_many_attached` + +The `has_many_attached` macro sets up a one-to-many relationship between records +and files. Each record can have many files attached to it. + +For example, suppose your application has a `Message` model. If you want each +message to have many images, define the `Message` model like this: + +```ruby +class Message < ApplicationRecord + has_many_attached :images +end +``` + +You can create a message with images: + +```ruby +class MessagesController < ApplicationController + def create + message = Message.create!(message_params) + redirect_to message + end + + private + def message_params + params.require(:message).permit(:title, :content, images: []) + end +end +``` + +Call `images.attach` to add new images to an existing message: + +```ruby +@message.images.attach(params[:images]) +``` + +Call `images.attached?` to determine whether a particular message has any images: + +```ruby +@message.images.attached? +``` + +Removing Files +-------------- + +To remove an attachment from a model, call `purge` on the attachment. Removal +can be done in the background if your application is setup to use Active Job. +Purging deletes the blob and the file from the storage service. + +```ruby +# Synchronously destroy the avatar and actual resource files. +user.avatar.purge + +# Destroy the associated models and actual resource files async, via Active Job. +user.avatar.purge_later +``` + +Linking to Files +---------------- + +Generate a permanent URL for the blob that points to the application. Upon +access, a redirect to the actual service endpoint is returned. This indirection +decouples the public URL from the actual one, and allows, for example, mirroring +attachments in different services for high-availability. The redirection has an +HTTP expiration of 5 min. + +```ruby +url_for(user.avatar) +``` + +To create a download link, use the `rails_blob_{path|url}` helper. Using this +helper allows you to set the disposition. + +```ruby +rails_blob_path(user.avatar, disposition: "attachment") +``` + +Transforming Images +------------------- + +To create variation of the image, call `variant` on the Blob. +You can pass any [MiniMagick](https://github.com/minimagick/minimagick) +supported transformation to the method. + +To enable variants, add `mini_magick` to your `Gemfile`: + +```ruby +gem 'mini_magick' +``` + +When the browser hits the variant URL, Active Storage will lazy transform the +original blob into the format you specified and redirect to its new service +location. + +```erb +<%= image_tag user.avatar.variant(resize: "100x100") %> +``` + +Previewing Files +---------------- + +Some non-image files can be previewed: that is, they can be presented as images. +For example, a video file can be previewed by extracting its first frame. Out of +the box, Active Storage supports previewing videos and PDF documents. + +```erb +<ul> + <% @message.files.each do |file| %> + <li> + <%= image_tag file.preview(resize: "100x100>") %> + </li> + <% end %> +</ul> +``` + +WARNING: Extracting previews requires third-party applications, `ffmpeg` for +video and `mutool` for PDFs. These libraries are not provided by Rails. You must +install them yourself to use the built-in previewers. Before you install and use +third-party software, make sure you understand the licensing implications of +doing so. + +Direct Uploads +-------------- + +Active Storage, with its included JavaScript library, supports uploading +directly from the client to the cloud. + +### Direct upload installation + +1. Include `activestorage.js` in your application's JavaScript bundle. + + Using the asset pipeline: + + ```js + //= require activestorage + + ``` + + Using the npm package: + + ```js + import * as ActiveStorage from "activestorage" + ActiveStorage.start() + ``` + +2. Annotate file inputs with the direct upload URL. + + ```ruby + <%= form.file_field :attachments, multiple: true, direct_upload: true %> + ``` +3. That's it! Uploads begin upon form submission. + +### Direct upload JavaScript events + +| Event name | Event target | Event data (`event.detail`) | Description | +| --- | --- | --- | --- | +| `direct-uploads:start` | `<form>` | None | A form containing files for direct upload fields was submitted. | +| `direct-upload:initialize` | `<input>` | `{id, file}` | Dispatched for every file after form submission. | +| `direct-upload:start` | `<input>` | `{id, file}` | A direct upload is starting. | +| `direct-upload:before-blob-request` | `<input>` | `{id, file, xhr}` | Before making a request to your application for direct upload metadata. | +| `direct-upload:before-storage-request` | `<input>` | `{id, file, xhr}` | Before making a request to store a file. | +| `direct-upload:progress` | `<input>` | `{id, file, progress}` | As requests to store files progress. | +| `direct-upload:error` | `<input>` | `{id, file, error}` | An error occurred. An `alert` will display unless this event is canceled. | +| `direct-upload:end` | `<input>` | `{id, file}` | A direct upload has ended. | +| `direct-uploads:end` | `<form>` | None | All direct uploads have ended. | + +### Example + +You can use these events to show the progress of an upload. + + + +To show the uploaded files in a form: + +```js +// direct_uploads.js + +addEventListener("direct-upload:initialize", event => { + const { target, detail } = event + const { id, file } = detail + target.insertAdjacentHTML("beforebegin", ` + <div id="direct-upload-${id}" class="direct-upload direct-upload--pending"> + <div id="direct-upload-progress-${id}" class="direct-upload__progress" style="width: 0%"></div> + <span class="direct-upload__filename">${file.name}</span> + </div> + `) +}) + +addEventListener("direct-upload:start", event => { + const { id } = event.detail + const element = document.getElementById(`direct-upload-${id}`) + element.classList.remove("direct-upload--pending") +}) + +addEventListener("direct-upload:progress", event => { + const { id, progress } = event.detail + const progressElement = document.getElementById(`direct-upload-progress-${id}`) + progressElement.style.width = `${progress}%` +}) + +addEventListener("direct-upload:error", event => { + event.preventDefault() + const { id, error } = event.detail + const element = document.getElementById(`direct-upload-${id}`) + element.classList.add("direct-upload--error") + element.setAttribute("title", error) +}) + +addEventListener("direct-upload:end", event => { + const { id } = event.detail + const element = document.getElementById(`direct-upload-${id}`) + element.classList.add("direct-upload--complete") +}) +``` + +Add styles: + +```css +/* direct_uploads.css */ + +.direct-upload { + display: inline-block; + position: relative; + padding: 2px 4px; + margin: 0 3px 3px 0; + border: 1px solid rgba(0, 0, 0, 0.3); + border-radius: 3px; + font-size: 11px; + line-height: 13px; +} + +.direct-upload--pending { + opacity: 0.6; +} + +.direct-upload__progress { + position: absolute; + top: 0; + left: 0; + bottom: 0; + opacity: 0.2; + background: #0076ff; + transition: width 120ms ease-out, opacity 60ms 60ms ease-in; + transform: translate3d(0, 0, 0); +} + +.direct-upload--complete .direct-upload__progress { + opacity: 0.4; +} + +.direct-upload--error { + border-color: red; +} + +input[type=file][data-direct-upload-url][disabled] { + display: none; +} +``` + +Discarding Files Stored During System Tests +------------------------------------------- + +System tests clean up test data by rolling back a transaction. Because destroy +is never called on an object, the attached files are never cleaned up. If you +want to clear the files, you can do it in an `after_teardown` callback. Doing it +here ensures that all connections created during the test are complete and +you won't receive an error from Active Storage saying it can't find a file. + +```ruby +class ApplicationSystemTestCase < ActionDispatch::SystemTestCase + driven_by :selenium, using: :chrome, screen_size: [1400, 1400] + + def remove_uploaded_files + FileUtils.rm_rf("#{Rails.root}/storage_test") + end + + def after_teardown + super + remove_uploaded_files + end +end +``` + +If your system tests verify the deletion of a model with attachments and you're +using Active Job, set your test environment to use the inline queue adapter so +the purge job is executed immediately rather at an unknown time in the future. + +You may also want to use a separate service definition for the test environment +so your tests don't delete the files you create during development. + +```ruby +# Use inline job processing to make things happen immediately +config.active_job.queue_adapter = :inline + +# Separate file storage in the test environment +config.active_storage.service = :local_test +``` + +Implementing Support for Other Cloud Services +--------------------------------------------- + +If you need to support a cloud service other than these, you will need to +implement the Service. Each service extends +[`ActiveStorage::Service`](https://github.com/rails/rails/blob/master/activestorage/lib/active_storage/service.rb) +by implementing the methods necessary to upload and download files to the cloud. diff --git a/guides/source/active_support_core_extensions.md b/guides/source/active_support_core_extensions.md index f3d8e05089..8e2826bb85 100644 --- a/guides/source/active_support_core_extensions.md +++ b/guides/source/active_support_core_extensions.md @@ -135,36 +135,53 @@ NOTE: Defined in `active_support/core_ext/object/blank.rb`. ### `duplicable?` -A few fundamental objects in Ruby are singletons. For example, in the whole life of a program the integer 1 refers always to the same instance: +In Ruby 2.4 most objects can be duplicated via `dup` or `clone` except +methods and certain numbers. Though Ruby 2.2 and 2.3 can't duplicate `nil`, +`false`, `true`, and symbols as well as instances `Float`, `Fixnum`, +and `Bignum` instances. ```ruby -1.object_id # => 3 -Math.cos(0).to_i.object_id # => 3 +"foo".dup # => "foo" +"".dup # => "" +1.method(:+).dup # => TypeError: allocator undefined for Method +Complex(0).dup # => TypeError: can't copy Complex ``` -Hence, there's no way these objects can be duplicated through `dup` or `clone`: +Active Support provides `duplicable?` to query an object about this: ```ruby -true.dup # => TypeError: can't dup TrueClass +"foo".duplicable? # => true +"".duplicable? # => true +Rational(1).duplicable? # => false +Complex(1).duplicable? # => false +1.method(:+).duplicable? # => false ``` -Some numbers which are not singletons are not duplicable either: +`duplicable?` matches Ruby's `dup` according to the Ruby version. + +So in 2.4: ```ruby -0.0.clone # => allocator undefined for Float -(2**1024).clone # => allocator undefined for Bignum +nil.dup # => nil +:my_symbol.dup # => :my_symbol +1.dup # => 1 + +nil.duplicable? # => true +:my_symbol.duplicable? # => true +1.duplicable? # => true ``` -Active Support provides `duplicable?` to programmatically query an object about this property: +Whereas in 2.2 and 2.3: ```ruby -"foo".duplicable? # => true -"".duplicable? # => true -0.0.duplicable? # => false -false.duplicable? # => false -``` +nil.dup # => TypeError: can't dup NilClass +:my_symbol.dup # => TypeError: can't dup Symbol +1.dup # => TypeError: can't dup Fixnum -By definition all objects are `duplicable?` except `nil`, `false`, `true`, symbols, numbers, class, module, and method objects. +nil.duplicable? # => false +:my_symbol.duplicable? # => false +1.duplicable? # => false +``` 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. @@ -172,7 +189,7 @@ 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 a 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'] @@ -248,6 +265,13 @@ end @person.try { |p| "#{p.first_name} #{p.last_name}" } ``` +Note that `try` will swallow no-method errors, returning nil instead. If you want to protect against typos, use `try!` instead: + +```ruby +@number.try(:nest) # => nil +@number.try!(:nest) # NoMethodError: undefined method `nest' for 1:Integer +``` + NOTE: Defined in `active_support/core_ext/object/try.rb`. ### `class_eval(*args, &block)` @@ -361,7 +385,7 @@ account.to_query('company[name]') so its output is ready to be used in a query string. -Arrays return the result of applying `to_query` to each element with `_key_[]` as key, and join the result with "&": +Arrays return the result of applying `to_query` to each element with `key[]` as key, and join the result with "&": ```ruby [3.4, -45.6].to_query('sample') @@ -390,7 +414,7 @@ The method `with_options` provides a way to factor out common options in a serie Given a default options hash, `with_options` yields a proxy object to a block. Within the block, methods called on the proxy are forwarded to the receiver with their options merged. For example, you get rid of the duplication in: ```ruby -class Account < ActiveRecord::Base +class Account < ApplicationRecord has_many :customers, dependent: :destroy has_many :products, dependent: :destroy has_many :invoices, dependent: :destroy @@ -401,7 +425,7 @@ end this way: ```ruby -class Account < ActiveRecord::Base +class Account < ApplicationRecord with_options dependent: :destroy do |assoc| assoc.has_many :customers assoc.has_many :products @@ -453,7 +477,7 @@ NOTE: Defined in `active_support/core_ext/object/instance_variables.rb`. #### `instance_variable_names` -The method `instance_variable_names` returns an array. Each name includes the "@" sign. +The method `instance_variable_names` returns an array. Each name includes the "@" sign. ```ruby class C @@ -475,7 +499,7 @@ The methods `silence_warnings` and `enable_warnings` change the value of `$VERBO silence_warnings { Object.const_set "RAILS_DEFAULT_LOGGER", logger } ``` -Silencing exceptions is also possible with `suppress`. This method receives an arbitrary number of exception classes. If an exception is raised during the execution of the block and is `kind_of?` any of the arguments, `suppress` captures it and returns silently. Otherwise the exception is reraised: +Silencing exceptions is also possible with `suppress`. This method receives an arbitrary number of exception classes. If an exception is raised during the execution of the block and is `kind_of?` any of the arguments, `suppress` captures it and returns silently. Otherwise the exception is not captured: ```ruby # If the user is locked, the increment is lost, no big deal. @@ -504,56 +528,6 @@ NOTE: Defined in `active_support/core_ext/object/inclusion.rb`. Extensions to `Module` ---------------------- -### `alias_method_chain` - -**This method is deprecated in favour of using Module#prepend.** - -Using plain Ruby you can wrap methods with other methods, that's called _alias chaining_. - -For example, let's say you'd like params to be strings in functional tests, as they are in real requests, but still want the convenience of assigning integers and other kind of values. To accomplish that you could wrap `ActionController::TestCase#process` this way in `test/test_helper.rb`: - -```ruby -ActionController::TestCase.class_eval do - # save a reference to the original process method - alias_method :original_process, :process - - # now redefine process and delegate to original_process - def process(action, params=nil, session=nil, flash=nil, http_method='GET') - params = Hash[*params.map {|k, v| [k, v.to_s]}.flatten] - original_process(action, params, session, flash, http_method) - end -end -``` - -That's the method `get`, `post`, etc., delegate the work to. - -That technique has a risk, it could be the case that `:original_process` was taken. To try to avoid collisions people choose some label that characterizes what the chaining is about: - -```ruby -ActionController::TestCase.class_eval do - def process_with_stringified_params(...) - params = Hash[*params.map {|k, v| [k, v.to_s]}.flatten] - process_without_stringified_params(action, params, session, flash, http_method) - end - alias_method :process_without_stringified_params, :process - alias_method :process, :process_with_stringified_params -end -``` - -The method `alias_method_chain` provides a shortcut for that pattern: - -```ruby -ActionController::TestCase.class_eval do - def process_with_stringified_params(...) - params = Hash[*params.map {|k, v| [k, v.to_s]}.flatten] - process_without_stringified_params(action, params, session, flash, http_method) - end - alias_method_chain :process, :stringified_params -end -``` - -NOTE: Defined in `active_support/core_ext/module/aliasing.rb`. - ### Attributes #### `alias_attribute` @@ -561,7 +535,7 @@ NOTE: Defined in `active_support/core_ext/module/aliasing.rb`. 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 +class User < ApplicationRecord # You can refer to the email column as "login". # This can be meaningful for authentication code. alias_attribute :login, :email @@ -625,8 +599,6 @@ module ActiveSupport mattr_accessor :load_once_paths mattr_accessor :autoloaded_constants mattr_accessor :explicitly_unloadable_constants - mattr_accessor :logger - mattr_accessor :log_activity mattr_accessor :constant_watch_stack mattr_accessor :constant_watch_stack_mutex end @@ -662,7 +634,7 @@ NOTE: Defined in `active_support/core_ext/module/introspection.rb`. #### `parent_name` -The `parent_name` method on a nested named module returns the fully-qualified name of the module that contains its corresponding constant: +The `parent_name` method on a nested named module returns the fully qualified name of the module that contains its corresponding constant: ```ruby module X @@ -702,125 +674,6 @@ M.parents # => [X::Y, X, Object] NOTE: Defined in `active_support/core_ext/module/introspection.rb`. -### Constants - -The method `local_constants` returns the names of the constants that have been -defined in the receiver module: - -```ruby -module X - X1 = 1 - X2 = 2 - module Y - Y1 = :y1 - X1 = :overrides_X1_above - end -end - -X.local_constants # => [:X1, :X2, :Y] -X::Y.local_constants # => [:Y1, :X1] -``` - -The names are returned as symbols. - -NOTE: Defined in `active_support/core_ext/module/introspection.rb`. - -#### Qualified Constant Names - -The standard methods `const_defined?`, `const_get`, and `const_set` accept -bare constant names. Active Support extends this API to be able to pass -relative qualified constant names. - -The new methods are `qualified_const_defined?`, `qualified_const_get`, and -`qualified_const_set`. Their arguments are assumed to be qualified constant -names relative to their receiver: - -```ruby -Object.qualified_const_defined?("Math::PI") # => true -Object.qualified_const_get("Math::PI") # => 3.141592653589793 -Object.qualified_const_set("Math::Phi", 1.618034) # => 1.618034 -``` - -Arguments may be bare constant names: - -```ruby -Math.qualified_const_get("E") # => 2.718281828459045 -``` - -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 -walking down the path. - -For example, given - -```ruby -module M - X = 1 -end - -module N - class C - include M - end -end -``` - -`qualified_const_defined?` behaves this way: - -```ruby -N.qualified_const_defined?("C::X", false) # => false -N.qualified_const_defined?("C::X", true) # => true -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 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`. - -### Reachable - -A named module is reachable if it is stored in its corresponding constant. It means you can reach the module object via the constant. - -That is what ordinarily happens, if a module is called "M", the `M` constant exists and holds it: - -```ruby -module M -end - -M.reachable? # => true -``` - -But since constants and modules are indeed kind of decoupled, module objects can become unreachable: - -```ruby -module M -end - -orphan = Object.send(:remove_const, :M) - -# The module object is orphan now but it still has a name. -orphan.name # => "M" - -# You cannot reach it via the constant M because it does not even exist. -orphan.reachable? # => false - -# Let's define a module called "M" again. -module M -end - -# The constant M exists now again, and it stores a module -# object called "M", but it is a new instance. -orphan.reachable? # => false -``` - -NOTE: Defined in `active_support/core_ext/module/reachable.rb`. - ### Anonymous A module may or may not have a name: @@ -854,7 +707,6 @@ end m = Object.send(:remove_const, :M) -m.reachable? # => false m.anonymous? # => false ``` @@ -864,12 +716,14 @@ NOTE: Defined in `active_support/core_ext/module/anonymous.rb`. ### Method Delegation +#### `delegate` + The macro `delegate` offers an easy way to forward methods. Let's imagine that users in some application have login information in the `User` model but name and other data in a separate `Profile` model: ```ruby -class User < ActiveRecord::Base +class User < ApplicationRecord has_one :profile end ``` @@ -877,7 +731,7 @@ end 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 +class User < ApplicationRecord has_one :profile def name @@ -889,7 +743,7 @@ end That is what `delegate` does for you: ```ruby -class User < ActiveRecord::Base +class User < ApplicationRecord has_one :profile delegate :name, to: :profile @@ -946,13 +800,36 @@ In the previous example the macro generates `avatar_size` rather than `size`. NOTE: Defined in `active_support/core_ext/module/delegation.rb` +#### `delegate_missing_to` + +Imagine you would like to delegate everything missing from the `User` object, +to the `Profile` one. The `delegate_missing_to` macro lets you implement this +in a breeze: + +```ruby +class User < ApplicationRecord + has_one :profile + + delegate_missing_to :profile +end +``` + +The target can be anything callable within the object, e.g. instance variables, +methods, constants, etc. Only the public methods of the target are delegated. + +NOTE: Defined in `active_support/core_ext/module/delegation.rb`. + ### Redefining Methods 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. -NOTE: Defined in `active_support/core_ext/module/remove_method.rb` +You can also use `silence_redefinition_of_method` if you need to define +the replacement method yourself (because you're using `delegate`, for +example). + +NOTE: Defined in `active_support/core_ext/module/redefine_method.rb`. Extensions to `Class` --------------------- @@ -1015,8 +892,7 @@ The generation of the writer instance method can be prevented by setting the opt ```ruby module ActiveRecord class Base - class_attribute :table_name_prefix, instance_writer: false - self.table_name_prefix = "" + class_attribute :table_name_prefix, instance_writer: false, default: "my" end end ``` @@ -1030,7 +906,8 @@ class A class_attribute :x, instance_reader: false end -A.new.x = 1 # NoMethodError +A.new.x = 1 +A.new.x # NoMethodError ``` For convenience `class_attribute` also defines an instance predicate which is the double negation of what the instance reader returns. In the examples above it would be called `x?`. @@ -1039,7 +916,7 @@ When `:instance_reader` is `false`, the instance predicate returns a `NoMethodEr 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` +NOTE: Defined in `active_support/core_ext/class/attribute.rb`. #### `cattr_reader`, `cattr_writer`, and `cattr_accessor` @@ -1048,8 +925,7 @@ The macros `cattr_reader`, `cattr_writer`, and `cattr_accessor` are analogous to ```ruby class MysqlAdapter < AbstractAdapter # Generates class methods to access @@emulate_booleans. - cattr_accessor :emulate_booleans - self.emulate_booleans = true + cattr_accessor :emulate_booleans, default: true end ``` @@ -1058,8 +934,7 @@ Instance methods are created as well for convenience, they are just proxies to t ```ruby module ActionView class Base - cattr_accessor :field_error_proc - @@field_error_proc = Proc.new{ ... } + cattr_accessor :field_error_proc, default: Proc.new { ... } end end ``` @@ -1071,7 +946,7 @@ Also, you can pass a block to `cattr_*` to set up the attribute with a default v ```ruby class MysqlAdapter < AbstractAdapter # Generates class methods to access @@emulate_booleans with default value of true. - cattr_accessor(:emulate_booleans) { true } + cattr_accessor :emulate_booleans, default: true end ``` @@ -1679,19 +1554,6 @@ Given a string with a qualified constant reference expression, `deconstantize` r "Admin::Hotel::ReservationUtils".deconstantize # => "Admin::Hotel" ``` -Active Support for example uses this method in `Module#qualified_const_set`: - -```ruby -def qualified_const_set(path, value) - QualifiedConstUtils.raise_if_absolute(path) - - const_name = path.demodulize - mod_name = path.deconstantize - mod = mod_name.empty? ? self : qualified_const_get(mod_name) - mod.const_set(const_name, value) -end -``` - NOTE: Defined in `active_support/core_ext/string/inflections.rb`. #### `parameterize` @@ -1703,6 +1565,20 @@ The method `parameterize` normalizes its receiver in a way that can be used in p "Kurt Gödel".parameterize # => "kurt-godel" ``` +To preserve the case of the string, set the `preserve_case` argument to true. By default, `preserve_case` is set to false. + +```ruby +"John Smith".parameterize(preserve_case: true) # => "John-Smith" +"Kurt Gödel".parameterize(preserve_case: true) # => "Kurt-Godel" +``` + +To use a custom separator, override the `separator` argument. + +```ruby +"John Smith".parameterize(separator: "_") # => "john\_smith" +"Kurt Gödel".parameterize(separator: "_") # => "kurt\_godel" +``` + In fact, the result string is wrapped in an instance of `ActiveSupport::Multibyte::Chars`. NOTE: Defined in `active_support/core_ext/string/inflections.rb`. @@ -1746,7 +1622,7 @@ NOTE: Defined in `active_support/core_ext/string/inflections.rb`. The method `constantize` resolves the constant reference expression in its receiver: ```ruby -"Fixnum".constantize # => Fixnum +"Integer".constantize # => Integer module M X = 1 @@ -1798,7 +1674,7 @@ Specifically performs these transformations: * Capitalizes the first word. The capitalization of the first word can be turned off by setting the -+:capitalize+ option to false (default is true). +`:capitalize` option to false (default is true). ```ruby "name".humanize # => "Name" @@ -1865,18 +1741,18 @@ The methods `to_date`, `to_time`, and `to_datetime` are basically convenience wr ```ruby "2010-07-27".to_date # => Tue, 27 Jul 2010 -"2010-07-27 23:37:00".to_time # => Tue Jul 27 23:37:00 UTC 2010 +"2010-07-27 23:37:00".to_time # => 2010-07-27 23:37:00 +0200 "2010-07-27 23:37:00".to_datetime # => Tue, 27 Jul 2010 23:37:00 +0000 ``` `to_time` receives an optional argument `:utc` or `:local`, to indicate which time zone you want the time in: ```ruby -"2010-07-27 23:42:00".to_time(:utc) # => Tue Jul 27 23:42:00 UTC 2010 -"2010-07-27 23:42:00".to_time(:local) # => Tue Jul 27 23:42:00 +0200 2010 +"2010-07-27 23:42:00".to_time(:utc) # => 2010-07-27 23:42:00 UTC +"2010-07-27 23:42:00".to_time(:local) # => 2010-07-27 23:42:00 +0200 ``` -Default is `:utc`. +Default is `:local`. Please refer to the documentation of `Date._parse` for further details. @@ -1920,7 +1796,7 @@ NOTE: Defined in `active_support/core_ext/numeric/bytes.rb`. ### Time -Enables the use of time calculations and declarations, like `45.minutes + 2.hours + 4.years`. +Enables the use of time calculations and declarations, like `45.minutes + 2.hours + 4.weeks`. These methods use Time#advance for precise date calculations when using from_now, ago, etc. as well as adding or subtracting their results from a Time object. For example: @@ -1929,13 +1805,17 @@ as well as adding or subtracting their results from a Time object. For example: # equivalent to Time.current.advance(months: 1) 1.month.from_now -# equivalent to Time.current.advance(years: 2) -2.years.from_now +# equivalent to Time.current.advance(weeks: 2) +2.weeks.from_now -# equivalent to Time.current.advance(months: 4, years: 5) -(4.months + 5.years).from_now +# equivalent to Time.current.advance(months: 4, weeks: 5) +(4.months + 5.weeks).from_now ``` +WARNING. For other durations please refer to the time extensions to `Integer`. + +NOTE: Defined in `active_support/core_ext/numeric/time.rb`. + ### Formatting Enables the formatting of numbers in a variety of ways. @@ -2001,12 +1881,14 @@ Produce a string representation of a number rounded to a precision: Produce a string representation of a number as a human-readable number of bytes: ```ruby -123.to_s(:human_size) # => 123 Bytes -1234.to_s(:human_size) # => 1.21 KB -12345.to_s(:human_size) # => 12.1 KB -1234567.to_s(:human_size) # => 1.18 MB -1234567890.to_s(:human_size) # => 1.15 GB -1234567890123.to_s(:human_size) # => 1.12 TB +123.to_s(:human_size) # => 123 Bytes +1234.to_s(:human_size) # => 1.21 KB +12345.to_s(:human_size) # => 12.1 KB +1234567.to_s(:human_size) # => 1.18 MB +1234567890.to_s(:human_size) # => 1.15 GB +1234567890123.to_s(:human_size) # => 1.12 TB +1234567890123456.to_s(:human_size) # => 1.1 PB +1234567890123456789.to_s(:human_size) # => 1.07 EB ``` Produce a string representation of a number in human-readable words: @@ -2067,34 +1949,48 @@ The method `ordinalize` returns the ordinal string corresponding to the receiver NOTE: Defined in `active_support/core_ext/integer/inflections.rb`. -Extensions to `BigDecimal` --------------------------- -### `to_s` +### Time -The method `to_s` is aliased to `to_formatted_s`. This provides a convenient way to display a BigDecimal value in floating-point notation: +Enables the use of time calculations and declarations, like `4.months + 5.years`. + +These methods use Time#advance for precise date calculations when using from_now, ago, etc. +as well as adding or subtracting their results from a Time object. For example: ```ruby -BigDecimal.new(5.00, 6).to_s # => "5.0" +# equivalent to Time.current.advance(months: 1) +1.month.from_now + +# equivalent to Time.current.advance(years: 2) +2.years.from_now + +# equivalent to Time.current.advance(months: 4, years: 5) +(4.months + 5.years).from_now ``` -### `to_formatted_s` +WARNING. For other durations please refer to the time extensions to `Numeric`. + +NOTE: Defined in `active_support/core_ext/integer/time.rb`. + +Extensions to `BigDecimal` +-------------------------- +### `to_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: +The method `to_s` provides a default specifier of "F". This means that a simple call to `to_s` will result in floating point representation instead of engineering notation: ```ruby -BigDecimal.new(5.00, 6).to_formatted_s # => "5.0" +BigDecimal(5.00, 6).to_s # => "5.0" ``` and that symbol specifiers are also supported: ```ruby -BigDecimal.new(5.00, 6).to_formatted_s(:db) # => "5.0" +BigDecimal(5.00, 6).to_s(:db) # => "5.0" ``` Engineering notation is still supported: ```ruby -BigDecimal.new(5.00, 6).to_formatted_s("e") # => "0.5E1" +BigDecimal(5.00, 6).to_s("e") # => "0.5E1" ``` Extensions to `Enumerable` @@ -2114,7 +2010,7 @@ Addition only assumes the elements respond to `+`: ```ruby [[1, 2], [2, 3], [3, 4]].sum # => [1, 2, 2, 3, 3, 4] %w(foo bar baz).sum # => "foobarbaz" -{a: 1, b: 2, c: 3}.sum # => [:b, 2, :c, 3, :a, 1] +{a: 1, b: 2, c: 3}.sum # => [:b, 2, :c, 3, :a, 1] ``` The sum of an empty collection is zero by default, but this is customizable: @@ -2188,7 +2084,17 @@ The method `without` returns a copy of an enumerable with the specified elements removed: ```ruby -people.without("Aaron", "Todd") +["David", "Rafael", "Aaron", "Todd"].without("Aaron", "Todd") # => ["David", "Rafael"] +``` + +NOTE: Defined in `active_support/core_ext/enumerable.rb`. + +### `pluck` + +The method `pluck` returns an array based on the given key: + +```ruby +[{ name: "David" }, { name: "Rafael" }, { name: "Aaron" }].pluck(:name) # => ["David", "Rafael", "Aaron"] ``` NOTE: Defined in `active_support/core_ext/enumerable.rb`. @@ -2201,22 +2107,22 @@ Extensions to `Array` Active Support augments the API of arrays to ease certain ways of accessing them. For example, `to` returns the subarray of elements up to the one at the passed index: ```ruby -%w(a b c d).to(2) # => %w(a b c) +%w(a b c d).to(2) # => ["a", "b", "c"] [].to(7) # => [] ``` Similarly, `from` returns the tail from the element at the passed index to the end. If the index is greater than the length of the array, it returns an empty array. ```ruby -%w(a b c d).from(2) # => %w(c d) +%w(a b c d).from(2) # => ["c", "d"] %w(a b c d).from(10) # => [] [].from(0) # => [] ``` -The methods `second`, `third`, `fourth`, and `fifth` return the corresponding element (`first` is built-in). Thanks to social wisdom and positive constructiveness all around, `forty_two` is also available. +The methods `second`, `third`, `fourth`, and `fifth` return the corresponding element, as do `second_to_last` and `third_to_last` (`first` and `last` are built-in). Thanks to social wisdom and positive constructiveness all around, `forty_two` is also available. ```ruby -%w(a b c d).third # => c +%w(a b c d).third # => "c" %w(a b c d).fifth # => nil ``` @@ -2229,7 +2135,7 @@ NOTE: Defined in `active_support/core_ext/array/access.rb`. This method is an alias of `Array#unshift`. ```ruby -%w(a b c d).prepend('e') # => %w(e a b c d) +%w(a b c d).prepend('e') # => ["e", "a", "b", "c", "d"] [].prepend(10) # => [10] ``` @@ -2240,8 +2146,8 @@ NOTE: Defined in `active_support/core_ext/array/prepend_and_append.rb`. This method is an alias of `Array#<<`. ```ruby -%w(a b c d).append('e') # => %w(a b c d e) -[].append([1,2]) # => [[1,2]] +%w(a b c d).append('e') # => ["a", "b", "c", "d", "e"] +[].append([1,2]) # => [[1, 2]] ``` NOTE: Defined in `active_support/core_ext/array/prepend_and_append.rb`. @@ -2347,7 +2253,7 @@ Contributor.limit(2).order(:rank).to_xml To do so it sends `to_xml` to every item in turn, and collects the results under a root node. All items must respond to `to_xml`, an exception is raised otherwise. -By default, the name of the root element is the underscorized and dasherized plural of the name of the class of the first item, provided the rest of elements belong to that type (checked with `is_a?`) and they are not hashes. In the example above that's "contributors". +By default, the name of the root element is the underscored and dasherized plural of the name of the class of the first item, provided the rest of elements belong to that type (checked with `is_a?`) and they are not hashes. In the example above that's "contributors". If there's any element that does not belong to the type of the first one the root node becomes "objects": @@ -2428,7 +2334,7 @@ The method `Array.wrap` wraps its argument in an array unless it is already an a Specifically: -* If the argument is `nil` an empty list is returned. +* If the argument is `nil` an empty array is returned. * Otherwise, if the argument responds to `to_ary` it is invoked, and if the value of `to_ary` is not `nil`, it is returned. * Otherwise, an array with the argument as its single element is returned. @@ -2440,9 +2346,9 @@ Array.wrap(0) # => [0] This method is similar in purpose to `Kernel#Array`, but there are some differences: -* If the argument responds to `to_ary` the method is invoked. `Kernel#Array` moves on to try `to_a` if the returned value is `nil`, but `Array.wrap` returns `nil` right away. +* If the argument responds to `to_ary` the method is invoked. `Kernel#Array` moves on to try `to_a` if the returned value is `nil`, but `Array.wrap` returns an array with the argument as its single element right away. * If the returned value from `to_ary` is neither `nil` nor an `Array` object, `Kernel#Array` raises an exception, while `Array.wrap` does not, it just returns the value. -* It does not call `to_a` on the argument, though special-cases `nil` to return an empty array. +* It does not call `to_a` on the argument, if the argument does not respond to `to_ary` it returns an array with the argument as its single element. The last point is particularly worth comparing for some enumerables: @@ -2465,7 +2371,7 @@ NOTE: Defined in `active_support/core_ext/array/wrap.rb`. ### Duplicating -The method `Array.deep_dup` duplicates itself and all objects 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 @@ -2609,8 +2515,7 @@ To do so, the method loops over the pairs and builds nodes that depend on the _v ```ruby XML_TYPE_NAMES = { "Symbol" => "symbol", - "Fixnum" => "integer", - "Bignum" => "integer", + "Integer" => "integer", "BigDecimal" => "decimal", "Float" => "float", "TrueClass" => "boolean", @@ -2687,7 +2592,7 @@ 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 +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 @@ -2730,7 +2635,7 @@ The method `transform_keys` accepts a block and returns a hash that has applied ```ruby {nil => nil, 1 => 1, a: :a}.transform_keys { |key| key.to_s.upcase } -# => {"" => nil, "A" => :a, "1" => 1} +# => {"" => nil, "1" => 1, "A" => :a} ``` 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: @@ -2772,7 +2677,7 @@ The method `stringify_keys` returns a hash that has a stringified version of the ```ruby {nil => nil, 1 => 1, a: :a}.stringify_keys -# => {"" => nil, "a" => :a, "1" => 1} +# => {"" => nil, "1" => 1, "a" => :a} ``` 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: @@ -2814,7 +2719,7 @@ The method `symbolize_keys` returns a hash that has a symbolized version of the ```ruby {nil => nil, 1 => 1, "a" => "a"}.symbolize_keys -# => {1=>1, nil=>nil, :a=>"a"} +# => {nil=>nil, 1=>1, :a=>"a"} ``` WARNING. Note in the previous example only one key was symbolized. @@ -2883,7 +2788,7 @@ The method `transform_values` accepts a block and returns a hash that has applie ``` 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`. +NOTE: Defined in `active_support/core_ext/hash/transform_values.rb`. ### Slicing @@ -2891,7 +2796,7 @@ Ruby has built-in support for taking slices out of strings and arrays. Active Su ```ruby {a: 1, b: 2, c: 3}.slice(:a, :c) -# => {:c=>3, :a=>1} +# => {:a=>1, :c=>3} {a: 1, b: 2, c: 3}.slice(:b, :X) # => {:b=>2} # non-existing keys are ignored @@ -2985,6 +2890,24 @@ end NOTE: Defined in `active_support/core_ext/regexp.rb`. +### `match?` + +Rails implements `Regexp#match?` for Ruby versions prior to 2.4: + +```ruby +/oo/.match?('foo') # => true +/oo/.match?('bar') # => false +/oo/.match?('foo', 1) # => true +``` + +The backport has the same interface and lack of side-effects in the caller like +not setting `$1` and friends, but it does not have the speed benefits. Its +purpose is to be able to write 2.4 compatible code. Rails itself uses this +predicate internally for example. + +Active Support defines `Regexp#match?` only if not present, so code running +under 2.4 or later does run the original one and gets the performance boost. + Extensions to `Range` --------------------- @@ -3040,53 +2963,6 @@ The method `Range#overlaps?` says whether any two given ranges have non-void int NOTE: Defined in `active_support/core_ext/range/overlaps.rb`. -Extensions to `Proc` --------------------- - -### `bind` - -As you surely know Ruby has an `UnboundMethod` class whose instances are methods that belong to the limbo of methods without a self. The method `Module#instance_method` returns an unbound method for example: - -```ruby -Hash.instance_method(:delete) # => #<UnboundMethod: Hash#delete> -``` - -An unbound method is not callable as is, you need to bind it first to an object with `bind`: - -```ruby -clear = Hash.instance_method(:clear) -clear.bind({a: 1}).call # => {} -``` - -Active Support defines `Proc#bind` with an analogous purpose: - -```ruby -Proc.new { size }.bind([]).call # => 0 -``` - -As you see that's callable and bound to the argument, the return value is indeed a `Method`. - -NOTE: To do so `Proc#bind` actually creates a method under the hood. If you ever see a method with a weird name like `__bind_1256598120_237302` in a stack trace you know now where it comes from. - -Action Pack uses this trick in `rescue_from` for example, which accepts the name of a method and also a proc as callbacks for a given rescued exception. It has to call them in either case, so a bound method is returned by `handler_for_rescue`, thus simplifying the code in the caller: - -```ruby -def handler_for_rescue(exception) - _, rescuer = Array(rescue_handlers).reverse.detect do |klass_name, handler| - ... - end - - case rescuer - when Symbol - method(rescuer) - when Proc - rescuer.bind(self) - end -end -``` - -NOTE: Defined in `active_support/core_ext/proc.rb`. - Extensions to `Date` -------------------- @@ -3094,78 +2970,42 @@ Extensions to `Date` NOTE: All the following methods are defined in `active_support/core_ext/date/calculations.rb`. +```ruby +yesterday +tomorrow +beginning_of_week (at_beginning_of_week) +end_of_week (at_end_of_week) +monday +sunday +weeks_ago +prev_week (last_week) +next_week +months_ago +months_since +beginning_of_month (at_beginning_of_month) +end_of_month (at_end_of_month) +last_month +beginning_of_quarter (at_beginning_of_quarter) +end_of_quarter (at_end_of_quarter) +beginning_of_year (at_beginning_of_year) +end_of_year (at_end_of_year) +years_ago +years_since +last_year +on_weekday? +on_weekend? +``` + INFO: The following calculation methods have edge cases in October 1582, since days 5..14 just do not exist. This guide does not document their behavior around those days for brevity, but it is enough to say that they do what you would expect. That is, `Date.new(1582, 10, 4).tomorrow` returns `Date.new(1582, 10, 15)` and so on. Please check `test/core_ext/date_ext_test.rb` in the Active Support test suite for expected behavior. #### `Date.current` -Active Support defines `Date.current` to be today in the current time zone. That's like `Date.today`, except that it honors the user time zone, if defined. It also defines `Date.yesterday` and `Date.tomorrow`, and the instance predicates `past?`, `today?`, and `future?`, all of them relative to `Date.current`. +Active Support defines `Date.current` to be today in the current time zone. That's like `Date.today`, except that it honors the user time zone, if defined. It also defines `Date.yesterday` and `Date.tomorrow`, and the instance predicates `past?`, `today?`, `future?`, `on_weekday?` and `on_weekend?`, all of them relative to `Date.current`. When making Date comparisons using methods which honor the user time zone, make sure to use `Date.current` and not `Date.today`. There are cases where the user time zone might be in the future compared to the system time zone, which `Date.today` uses by default. This means `Date.today` may equal `Date.yesterday`. #### Named dates -##### `prev_year`, `next_year` - -In Ruby 1.9 `prev_year` and `next_year` return a date with the same day/month in the last or next year: - -```ruby -d = Date.new(2010, 5, 8) # => Sat, 08 May 2010 -d.prev_year # => Fri, 08 May 2009 -d.next_year # => Sun, 08 May 2011 -``` - -If date is the 29th of February of a leap year, you obtain the 28th: - -```ruby -d = Date.new(2000, 2, 29) # => Tue, 29 Feb 2000 -d.prev_year # => Sun, 28 Feb 1999 -d.next_year # => Wed, 28 Feb 2001 -``` - -`prev_year` is aliased to `last_year`. - -##### `prev_month`, `next_month` - -In Ruby 1.9 `prev_month` and `next_month` return the date with the same day in the last or next month: - -```ruby -d = Date.new(2010, 5, 8) # => Sat, 08 May 2010 -d.prev_month # => Thu, 08 Apr 2010 -d.next_month # => Tue, 08 Jun 2010 -``` - -If such a day does not exist, the last day of the corresponding month is returned: - -```ruby -Date.new(2000, 5, 31).prev_month # => Sun, 30 Apr 2000 -Date.new(2000, 3, 31).prev_month # => Tue, 29 Feb 2000 -Date.new(2000, 5, 31).next_month # => Fri, 30 Jun 2000 -Date.new(2000, 1, 31).next_month # => Tue, 29 Feb 2000 -``` - -`prev_month` is aliased to `last_month`. - -##### `prev_quarter`, `next_quarter` - -Same as `prev_month` and `next_month`. It returns the date with the same day in the previous or next quarter: - -```ruby -t = Time.local(2010, 5, 8) # => Sat, 08 May 2010 -t.prev_quarter # => Mon, 08 Feb 2010 -t.next_quarter # => Sun, 08 Aug 2010 -``` - -If such a day does not exist, the last day of the corresponding month is returned: - -```ruby -Time.local(2000, 7, 31).prev_quarter # => Sun, 30 Apr 2000 -Time.local(2000, 5, 31).prev_quarter # => Tue, 29 Feb 2000 -Time.local(2000, 10, 31).prev_quarter # => Mon, 30 Oct 2000 -Time.local(2000, 11, 31).next_quarter # => Wed, 28 Feb 2001 -``` - -`prev_quarter` is aliased to `last_quarter`. - ##### `beginning_of_week`, `end_of_week` The methods `beginning_of_week` and `end_of_week` return the dates for the @@ -3283,6 +3123,8 @@ Date.new(2012, 2, 29).years_ago(3) # => Sat, 28 Feb 2009 Date.new(2012, 2, 29).years_since(3) # => Sat, 28 Feb 2015 ``` +`last_year` is short-hand for `#years_ago(1)`. + ##### `months_ago`, `months_since` The methods `months_ago` and `months_since` work analogously for months: @@ -3299,6 +3141,8 @@ Date.new(2010, 4, 30).months_ago(2) # => Sun, 28 Feb 2010 Date.new(2009, 12, 31).months_since(2) # => Sun, 28 Feb 2010 ``` +`last_month` is short-hand for `#months_ago(1)`. + ##### `weeks_ago` The method `weeks_ago` works analogously for weeks: @@ -3461,33 +3305,7 @@ WARNING: `DateTime` is not aware of DST rules and so some of these methods have NOTE: All the following methods are defined in `active_support/core_ext/date_time/calculations.rb`. -The class `DateTime` is a subclass of `Date` so by loading `active_support/core_ext/date/calculations.rb` you inherit these methods and their aliases, except that they will always return datetimes: - -```ruby -yesterday -tomorrow -beginning_of_week (at_beginning_of_week) -end_of_week (at_end_of_week) -monday -sunday -weeks_ago -prev_week (last_week) -next_week -months_ago -months_since -beginning_of_month (at_beginning_of_month) -end_of_month (at_end_of_month) -prev_month (last_month) -next_month -beginning_of_quarter (at_beginning_of_quarter) -end_of_quarter (at_end_of_quarter) -beginning_of_year (at_beginning_of_year) -end_of_year (at_end_of_year) -years_ago -years_since -prev_year (last_year) -next_year -``` +The class `DateTime` is a subclass of `Date` so by loading `active_support/core_ext/date/calculations.rb` you inherit these methods and their aliases, except that they will always return datetimes. The following methods are reimplemented so you do **not** need to load `active_support/core_ext/date/calculations.rb` for these ones: @@ -3635,8 +3453,6 @@ Extensions to `Time` NOTE: All the following methods are defined in `active_support/core_ext/time/calculations.rb`. -Active Support adds to `Time` many of the methods available for `DateTime`: - ```ruby past? today? @@ -3648,6 +3464,8 @@ change advance ago since (in) +prev_day +next_day beginning_of_day (midnight, at_midnight, at_beginning_of_day) end_of_day beginning_of_hour (at_beginning_of_hour) @@ -3663,16 +3481,20 @@ months_ago months_since beginning_of_month (at_beginning_of_month) end_of_month (at_end_of_month) -prev_month (last_month) +prev_month next_month +last_month beginning_of_quarter (at_beginning_of_quarter) end_of_quarter (at_end_of_quarter) beginning_of_year (at_beginning_of_year) end_of_year (at_end_of_year) years_ago years_since -prev_year (last_year) +prev_year +last_year next_year +on_weekday? +on_weekend? ``` They are analogous. Please refer to their documentation above and take into account the following differences: @@ -3727,6 +3549,74 @@ now.all_year # => Fri, 01 Jan 2010 00:00:00 UTC +00:00..Fri, 31 Dec 2010 23:59:59 UTC +00:00 ``` +#### `prev_day`, `next_day` + +In Ruby 1.9 `prev_day` and `next_day` return the date in the last or next day: + +```ruby +d = Date.new(2010, 5, 8) # => Sat, 08 May 2010 +d.prev_day # => Fri, 07 May 2010 +d.next_day # => Sun, 09 May 2010 +``` + +#### `prev_month`, `next_month` + +In Ruby 1.9 `prev_month` and `next_month` return the date with the same day in the last or next month: + +```ruby +d = Date.new(2010, 5, 8) # => Sat, 08 May 2010 +d.prev_month # => Thu, 08 Apr 2010 +d.next_month # => Tue, 08 Jun 2010 +``` + +If such a day does not exist, the last day of the corresponding month is returned: + +```ruby +Date.new(2000, 5, 31).prev_month # => Sun, 30 Apr 2000 +Date.new(2000, 3, 31).prev_month # => Tue, 29 Feb 2000 +Date.new(2000, 5, 31).next_month # => Fri, 30 Jun 2000 +Date.new(2000, 1, 31).next_month # => Tue, 29 Feb 2000 +``` + +#### `prev_year`, `next_year` + +In Ruby 1.9 `prev_year` and `next_year` return a date with the same day/month in the last or next year: + +```ruby +d = Date.new(2010, 5, 8) # => Sat, 08 May 2010 +d.prev_year # => Fri, 08 May 2009 +d.next_year # => Sun, 08 May 2011 +``` + +If date is the 29th of February of a leap year, you obtain the 28th: + +```ruby +d = Date.new(2000, 2, 29) # => Tue, 29 Feb 2000 +d.prev_year # => Sun, 28 Feb 1999 +d.next_year # => Wed, 28 Feb 2001 +``` + +#### `prev_quarter`, `next_quarter` + +`prev_quarter` and `next_quarter` return the date with the same day in the previous or next quarter: + +```ruby +t = Time.local(2010, 5, 8) # => 2010-05-08 00:00:00 +0300 +t.prev_quarter # => 2010-02-08 00:00:00 +0200 +t.next_quarter # => 2010-08-08 00:00:00 +0300 +``` + +If such a day does not exist, the last day of the corresponding month is returned: + +```ruby +Time.local(2000, 7, 31).prev_quarter # => 2000-04-30 00:00:00 +0300 +Time.local(2000, 5, 31).prev_quarter # => 2000-02-29 00:00:00 +0200 +Time.local(2000, 10, 31).prev_quarter # => 2000-07-31 00:00:00 +0300 +Time.local(2000, 11, 31).next_quarter # => 2001-03-01 00:00:00 +0200 +``` + +`prev_quarter` is aliased to `last_quarter`. + ### Time Constructors Active Support defines `Time.current` to be `Time.zone.now` if there's a user time zone defined, with fallback to `Time.now`: @@ -3750,7 +3640,7 @@ Durations can be added to and subtracted from time objects: now = Time.current # => Mon, 09 Aug 2010 23:20:05 UTC +00:00 now + 1.year -# => Tue, 09 Aug 2011 23:21:11 UTC +00:00 +# => Tue, 09 Aug 2011 23:21:11 UTC +00:00 now - 1.week # => Mon, 02 Aug 2010 23:21:11 UTC +00:00 ``` @@ -3813,9 +3703,9 @@ Extensions to `NameError` Active Support adds `missing_name?` to `NameError`, which tests whether the exception was raised because of the name passed as argument. -The name may be given as a symbol or string. A symbol is tested against the bare constant name, a string is against the fully-qualified constant name. +The name may be given as a symbol or string. A symbol is tested against the bare constant name, a string is against the fully qualified constant name. -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. +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 `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: diff --git a/guides/source/active_support_instrumentation.md b/guides/source/active_support_instrumentation.md index 352da43b5f..11c4a8222a 100644 --- a/guides/source/active_support_instrumentation.md +++ b/guides/source/active_support_instrumentation.md @@ -19,7 +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](#rails-framework-hooks). 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. @@ -112,6 +112,7 @@ Action Controller | `:controller` | The controller name | | `:action` | The action | | `:params` | Hash of request parameters without any filtered parameter | +| `:headers` | Request headers | | `:format` | html/js/json/xml etc | | `:method` | HTTP request verb | | `:path` | Request path | @@ -121,6 +122,7 @@ Action Controller controller: "PostsController", action: "new", params: { "action" => "new", "controller" => "posts" }, + headers: #<ActionDispatch::Http::Headers:0x0055a67a519b88>, format: :html, method: "GET", path: "/posts/new" @@ -134,6 +136,7 @@ Action Controller | `:controller` | The controller name | | `:action` | The action | | `:params` | Hash of request parameters without any filtered parameter | +| `:headers` | Request headers | | `:format` | html/js/json/xml etc | | `:method` | HTTP request verb | | `:path` | Request path | @@ -146,6 +149,7 @@ Action Controller controller: "PostsController", action: "index", params: {"action" => "index", "controller" => "posts"}, + headers: #<ActionDispatch::Http::Headers:0x0055a67a519b88>, format: :html, method: "GET", path: "/posts", @@ -193,6 +197,12 @@ INFO. Additional keys may be added by the caller. } ``` +### unpermitted_parameters.action_controller + +| Key | Value | +| ------- | ---------------- | +| `:keys` | Unpermitted keys | + Action View ----------- @@ -222,16 +232,36 @@ Action View } ``` +### render_collection.action_view + +| Key | Value | +| ------------- | ------------------------------------- | +| `:identifier` | Full path to template | +| `:count` | Size of collection | +| `:cache_hits` | Number of partials fetched from cache | + +`:cache_hits` is only included if the collection is rendered with `cached: true`. + +```ruby +{ + identifier: "/Users/adam/projects/notifications/app/views/posts/_post.html.erb", + count: 3, + cache_hits: 0 +} +``` + Active Record ------------ ### sql.active_record -| Key | Value | -| ---------------- | --------------------- | -| `:sql` | SQL statement | -| `:name` | Name of the operation | -| `:connection_id` | `self.object_id` | +| Key | Value | +| ---------------- | ---------------------------------------- | +| `:sql` | SQL statement | +| `:name` | Name of the operation | +| `:connection_id` | `self.object_id` | +| `:binds` | Bind parameters | +| `:cached` | `true` is added when cached queries used | INFO. The adapters will add their own data as well. @@ -244,13 +274,19 @@ INFO. The adapters will add their own data as well. } ``` -### identity.active_record +### instantiation.active_record | Key | Value | | ---------------- | ----------------------------------------- | -| `:line` | Primary Key of object in the identity map | -| `:name` | Record's class | -| `:connection_id` | `self.object_id` | +| `:record_count` | Number of records that instantiated | +| `:class_name` | Record's class | + +```ruby +{ + record_count: 1, + class_name: "User" +} +``` Action Mailer ------------- @@ -274,7 +310,7 @@ Action Mailer mailer: "Notification", message_id: "4f5b5491f1774_181b23fc3d4434d38138e5@mba.local.mail", subject: "Rails Guides", - to: ["users@rails.com", "ddh@rails.com"], + to: ["users@rails.com", "dhh@rails.com"], from: ["me@rails.com"], date: Sat, 10 Mar 2012 14:18:09 +0100, mail: "..." # omitted for brevity @@ -300,23 +336,28 @@ Action Mailer mailer: "Notification", message_id: "4f5b5491f1774_181b23fc3d4434d38138e5@mba.local.mail", subject: "Rails Guides", - to: ["users@rails.com", "ddh@rails.com"], + to: ["users@rails.com", "dhh@rails.com"], from: ["me@rails.com"], date: Sat, 10 Mar 2012 14:18:09 +0100, mail: "..." # omitted for brevity } ``` -Active Resource --------------- +### process.action_mailer -### request.active_resource +| Key | Value | +| ------------- | ------------------------ | +| `:mailer` | Name of the mailer class | +| `:action` | The action | +| `:args` | The arguments | -| Key | Value | -| -------------- | -------------------- | -| `:method` | HTTP method | -| `:request_uri` | Complete URI | -| `:result` | HTTP response object | +```ruby +{ + mailer: "Notification", + action: "welcome_email", + args: [] +} +``` Active Support -------------- @@ -400,6 +441,131 @@ INFO. Cache stores may add their own keys } ``` +Active Job +-------- + +### enqueue_at.active_job + +| Key | Value | +| ------------ | -------------------------------------- | +| `:adapter` | QueueAdapter object processing the job | +| `:job` | Job object | + +### enqueue.active_job + +| Key | Value | +| ------------ | -------------------------------------- | +| `:adapter` | QueueAdapter object processing the job | +| `:job` | Job object | + +### perform_start.active_job + +| Key | Value | +| ------------ | -------------------------------------- | +| `:adapter` | QueueAdapter object processing the job | +| `:job` | Job object | + +### perform.active_job + +| Key | Value | +| ------------ | -------------------------------------- | +| `:adapter` | QueueAdapter object processing the job | +| `:job` | Job object | + +Action Cable +------------ + +### perform_action.action_cable + +| Key | Value | +| ---------------- | ------------------------- | +| `:channel_class` | Name of the channel class | +| `:action` | The action | +| `:data` | A hash of data | + +### transmit.action_cable + +| Key | Value | +| ---------------- | ------------------------- | +| `:channel_class` | Name of the channel class | +| `:data` | A hash of data | +| `:via` | Via | + +### transmit_subscription_confirmation.action_cable + +| Key | Value | +| ---------------- | ------------------------- | +| `:channel_class` | Name of the channel class | + +### transmit_subscription_rejection.action_cable + +| Key | Value | +| ---------------- | ------------------------- | +| `:channel_class` | Name of the channel class | + +### broadcast.action_cable + +| Key | Value | +| --------------- | -------------------- | +| `:broadcasting` | A named broadcasting | +| `:message` | A hash of message | +| `:coder` | The coder | + +Active Storage +-------------- + +### service_upload.active_storage + +| Key | Value | +| ------------ | ---------------------------- | +| `:key` | Secure token | +| `:service` | Name of the service | +| `:checksum` | Checksum to ensure integrity | + +### service_streaming_download.active_storage + +| Key | Value | +| ------------ | ------------------- | +| `:key` | Secure token | +| `:service` | Name of the service | + +### service_download.active_storage + +| Key | Value | +| ------------ | ------------------- | +| `:key` | Secure token | +| `:service` | Name of the service | + +### service_delete.active_storage + +| Key | Value | +| ------------ | ------------------- | +| `:key` | Secure token | +| `:service` | Name of the service | + +### service_delete_prefixed.active_storage + +| Key | Value | +| ------------ | ------------------- | +| `:prefix` | Key prefix | +| `:service` | Name of the service | + +### service_exist.active_storage + +| Key | Value | +| ------------ | --------------------------- | +| `:key` | Secure token | +| `:service` | Name of the service | +| `:exist` | File or blob exists or not | + +### service_url.active_storage + +| Key | Value | +| ------------ | ------------------- | +| `:key` | Secure token | +| `:service` | Name of the service | +| `:url` | Generated url | + Railties -------- @@ -430,7 +596,7 @@ The block receives the following arguments: * The name of the event * Time when it started * Time when it finished -* An unique ID for this event +* A unique ID for this event * The payload (described in previous sections) ```ruby @@ -498,4 +664,4 @@ end ``` You should follow Rails conventions when defining your own events. The format is: `event.library`. -If you application is sending Tweets, you should create an event named `tweet.twitter`. +If your application is sending Tweets, you should create an event named `tweet.twitter`. diff --git a/guides/source/api_app.md b/guides/source/api_app.md new file mode 100644 index 0000000000..b4d90d31de --- /dev/null +++ b/guides/source/api_app.md @@ -0,0 +1,426 @@ +**DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON http://guides.rubyonrails.org.** + +Using Rails for API-only Applications +===================================== + +In this guide you will learn: + +* What Rails provides for API-only applications +* How to configure Rails to start without any browser features +* How to decide which middleware you will want to include +* How to decide which modules to use in your controller + +-------------------------------------------------------------------------------- + +What is an API Application? +--------------------------- + +Traditionally, when people said that they used Rails as an "API", they meant +providing a programmatically accessible API alongside their web application. +For example, GitHub provides [an API](https://developer.github.com) that you +can use from your own custom clients. + +With the advent of client-side frameworks, more developers are using Rails to +build a back-end that is shared between their web application and other native +applications. + +For example, Twitter uses its [public API](https://dev.twitter.com) in its web +application, which is built as a static site that consumes JSON resources. + +Instead of using Rails to generate HTML that communicates with the server +through forms and links, many developers are treating their web application as +just an API client delivered as HTML with JavaScript that consumes a JSON API. + +This guide covers building a Rails application that serves JSON resources to an +API client, including client-side frameworks. + +Why Use Rails for JSON APIs? +---------------------------- + +The first question a lot of people have when thinking about building a JSON API +using Rails is: "isn't using Rails to spit out some JSON overkill? Shouldn't I +just use something like Sinatra?". + +For very simple APIs, this may be true. However, even in very HTML-heavy +applications, most of an application's logic lives outside of the view +layer. + +The reason most people use Rails is that it provides a set of defaults that +allows developers to get up and running quickly, without having to make a lot of trivial +decisions. + +Let's take a look at some of the things that Rails provides out of the box that are +still applicable to API applications. + +Handled at the middleware layer: + +- Reloading: Rails applications support transparent reloading. This works even if + your application gets big and restarting the server for every request becomes + non-viable. +- Development Mode: Rails applications come with smart defaults for development, + making development pleasant without compromising production-time performance. +- Test Mode: Ditto development mode. +- Logging: Rails applications log every request, with a level of verbosity + appropriate for the current mode. Rails logs in development include information + about the request environment, database queries, and basic performance + information. +- Security: Rails detects and thwarts [IP spoofing + attacks](https://en.wikipedia.org/wiki/IP_address_spoofing) and handles + cryptographic signatures in a [timing + attack](https://en.wikipedia.org/wiki/Timing_attack) aware way. Don't know what + an IP spoofing attack or a timing attack is? Exactly. +- Parameter Parsing: Want to specify your parameters as JSON instead of as a + URL-encoded String? No problem. Rails will decode the JSON for you and make + it available in `params`. Want to use nested URL-encoded parameters? That + works too. +- Conditional GETs: Rails handles conditional `GET` (`ETag` and `Last-Modified`) + processing request headers and returning the correct response headers and status + code. All you need to do is use the + [`stale?`](http://api.rubyonrails.org/classes/ActionController/ConditionalGet.html#method-i-stale-3F) + check in your controller, and Rails will handle all of the HTTP details for you. +- HEAD requests: Rails will transparently convert `HEAD` requests into `GET` ones, + and return just the headers on the way out. This makes `HEAD` work reliably in + all Rails APIs. + +While you could obviously build these up in terms of existing Rack middleware, +this list demonstrates that the default Rails middleware stack provides a lot +of value, even if you're "just generating JSON". + +Handled at the Action Pack layer: + +- Resourceful Routing: If you're building a RESTful JSON API, you want to be + using the Rails router. Clean and conventional mapping from HTTP to controllers + means not having to spend time thinking about how to model your API in terms + of HTTP. +- URL Generation: The flip side of routing is URL generation. A good API based + on HTTP includes URLs (see [the GitHub Gist API](https://developer.github.com/v3/gists/) + for an example). +- Header and Redirection Responses: `head :no_content` and + `redirect_to user_url(current_user)` come in handy. Sure, you could manually + add the response headers, but why? +- Caching: Rails provides page, action and fragment caching. Fragment caching + is especially helpful when building up a nested JSON object. +- Basic, Digest, and Token Authentication: Rails comes with out-of-the-box support + for three kinds of HTTP authentication. +- Instrumentation: Rails has an instrumentation API that triggers registered + handlers for a variety of events, such as action processing, sending a file or + data, redirection, and database queries. The payload of each event comes with + relevant information (for the action processing event, the payload includes + the controller, action, parameters, request format, request method and the + request's full path). +- Generators: It is often handy to generate a resource and get your model, + controller, test stubs, and routes created for you in a single command for + further tweaking. Same for migrations and others. +- Plugins: Many third-party libraries come with support for Rails that reduce + or eliminate the cost of setting up and gluing together the library and the + web framework. This includes things like overriding default generators, adding + Rake tasks, and honoring Rails choices (like the logger and cache back-end). + +Of course, the Rails boot process also glues together all registered components. +For example, the Rails boot process is what uses your `config/database.yml` file +when configuring Active Record. + +**The short version is**: you may not have thought about which parts of Rails +are still applicable even if you remove the view layer, but the answer turns out +to be most of it. + +The Basic Configuration +----------------------- + +If you're building a Rails application that will be an API server first and +foremost, you can start with a more limited subset of Rails and add in features +as needed. + +### Creating a new application + +You can generate a new api Rails app: + +```bash +$ rails new my_api --api +``` + +This will do three main things for you: + +- Configure your application to start with a more limited set of middleware + than normal. Specifically, it will not include any middleware primarily useful + for browser applications (like cookies support) by default. +- Make `ApplicationController` inherit from `ActionController::API` instead of + `ActionController::Base`. As with middleware, this will leave out any Action + Controller modules that provide functionalities primarily used by browser + applications. +- Configure the generators to skip generating views, helpers and assets when + you generate a new resource. + +### Changing an existing application + +If you want to take an existing application and make it an API one, read the +following steps. + +In `config/application.rb` add the following line at the top of the `Application` +class definition: + +```ruby +config.api_only = true +``` + +In `config/environments/development.rb`, set `config.debug_exception_response_format` +to configure the format used in responses when errors occur in development mode. + +To render an HTML page with debugging information, use the value `:default`. + +```ruby +config.debug_exception_response_format = :default +``` + +To render debugging information preserving the response format, use the value `:api`. + +```ruby +config.debug_exception_response_format = :api +``` + +By default, `config.debug_exception_response_format` is set to `:api`, when `config.api_only` is set to true. + +Finally, inside `app/controllers/application_controller.rb`, instead of: + +```ruby +class ApplicationController < ActionController::Base +end +``` + +do: + +```ruby +class ApplicationController < ActionController::API +end +``` + +Choosing Middleware +-------------------- + +An API application comes with the following middleware by default: + +- `Rack::Sendfile` +- `ActionDispatch::Static` +- `ActionDispatch::Executor` +- `ActiveSupport::Cache::Strategy::LocalCache::Middleware` +- `Rack::Runtime` +- `ActionDispatch::RequestId` +- `ActionDispatch::RemoteIp` +- `Rails::Rack::Logger` +- `ActionDispatch::ShowExceptions` +- `ActionDispatch::DebugExceptions` +- `ActionDispatch::Reloader` +- `ActionDispatch::Callbacks` +- `ActiveRecord::Migration::CheckPending` +- `Rack::Head` +- `Rack::ConditionalGet` +- `Rack::ETag` + +See the [internal middleware](rails_on_rack.html#internal-middleware-stack) +section of the Rack guide for further information on them. + +Other plugins, including Active Record, may add additional middleware. In +general, these middleware are agnostic to the type of application you are +building, and make sense in an API-only Rails application. + +You can get a list of all middleware in your application via: + +```bash +$ rails middleware +``` + +### Using the Cache Middleware + +By default, Rails will add a middleware that provides a cache store based on +the configuration of your application (memcache by default). This means that +the built-in HTTP cache will rely on it. + +For instance, using the `stale?` method: + +```ruby +def show + @post = Post.find(params[:id]) + + if stale?(last_modified: @post.updated_at) + render json: @post + end +end +``` + +The call to `stale?` will compare the `If-Modified-Since` header in the request +with `@post.updated_at`. If the header is newer than the last modified, this +action will return a "304 Not Modified" response. Otherwise, it will render the +response and include a `Last-Modified` header in it. + +Normally, this mechanism is used on a per-client basis. The cache middleware +allows us to share this caching mechanism across clients. We can enable +cross-client caching in the call to `stale?`: + +```ruby +def show + @post = Post.find(params[:id]) + + if stale?(last_modified: @post.updated_at, public: true) + render json: @post + end +end +``` + +This means that the cache middleware will store off the `Last-Modified` value +for a URL in the Rails cache, and add an `If-Modified-Since` header to any +subsequent inbound requests for the same URL. + +Think of it as page caching using HTTP semantics. + +### Using Rack::Sendfile + +When you use the `send_file` method inside a Rails controller, it sets the +`X-Sendfile` header. `Rack::Sendfile` is responsible for actually sending the +file. + +If your front-end server supports accelerated file sending, `Rack::Sendfile` +will offload the actual file sending work to the front-end server. + +You can configure the name of the header that your front-end server uses for +this purpose using `config.action_dispatch.x_sendfile_header` in the appropriate +environment's configuration file. + +You can learn more about how to use `Rack::Sendfile` with popular +front-ends in [the Rack::Sendfile +documentation](http://rubydoc.info/github/rack/rack/master/Rack/Sendfile). + +Here are some values for this header for some popular servers, once these servers are configured to support +accelerated file sending: + +```ruby +# Apache and lighttpd +config.action_dispatch.x_sendfile_header = "X-Sendfile" + +# Nginx +config.action_dispatch.x_sendfile_header = "X-Accel-Redirect" +``` + +Make sure to configure your server to support these options following the +instructions in the `Rack::Sendfile` documentation. + +### Using ActionDispatch::Request + +`ActionDispatch::Request#params` will take parameters from the client in the JSON +format and make them available in your controller inside `params`. + +To use this, your client will need to make a request with JSON-encoded parameters +and specify the `Content-Type` as `application/json`. + +Here's an example in jQuery: + +```javascript +jQuery.ajax({ + type: 'POST', + url: '/people', + dataType: 'json', + contentType: 'application/json', + data: JSON.stringify({ person: { firstName: "Yehuda", lastName: "Katz" } }), + success: function(json) { } +}); +``` + +`ActionDispatch::Request` will see the `Content-Type` and your parameters +will be: + +```ruby +{ :person => { :firstName => "Yehuda", :lastName => "Katz" } } +``` + +### Other Middleware + +Rails ships with a number of other middleware that you might want to use in an +API application, especially if one of your API clients is the browser: + +- `Rack::MethodOverride` +- `ActionDispatch::Cookies` +- `ActionDispatch::Flash` +- For session management + * `ActionDispatch::Session::CacheStore` + * `ActionDispatch::Session::CookieStore` + * `ActionDispatch::Session::MemCacheStore` + +Any of these middleware can be added via: + +```ruby +config.middleware.use Rack::MethodOverride +``` + +### Removing Middleware + +If you don't want to use a middleware that is included by default in the API-only +middleware set, you can remove it with: + +```ruby +config.middleware.delete ::Rack::Sendfile +``` + +Keep in mind that removing these middlewares will remove support for certain +features in Action Controller. + +Choosing Controller Modules +--------------------------- + +An API application (using `ActionController::API`) comes with the following +controller modules by default: + +- `ActionController::UrlFor`: Makes `url_for` and similar helpers available. +- `ActionController::Redirecting`: Support for `redirect_to`. +- `AbstractController::Rendering` and `ActionController::ApiRendering`: Basic support for rendering. +- `ActionController::Renderers::All`: Support for `render :json` and friends. +- `ActionController::ConditionalGet`: Support for `stale?`. +- `ActionController::BasicImplicitRender`: Makes sure to return an empty response, if there isn't an explicit one. +- `ActionController::StrongParameters`: Support for parameters white-listing in combination with Active Model mass assignment. +- `ActionController::ForceSSL`: Support for `force_ssl`. +- `ActionController::DataStreaming`: Support for `send_file` and `send_data`. +- `AbstractController::Callbacks`: Support for `before_action` and + similar helpers. +- `ActionController::Rescue`: Support for `rescue_from`. +- `ActionController::Instrumentation`: Support for the instrumentation + hooks defined by Action Controller (see [the instrumentation + guide](active_support_instrumentation.html#action-controller) for +more information regarding this). +- `ActionController::ParamsWrapper`: Wraps the parameters hash into a nested hash, + so that you don't have to specify root elements sending POST requests for instance. +- `ActionController::Head`: Support for returning a response with no content, only headers + +Other plugins may add additional modules. You can get a list of all modules +included into `ActionController::API` in the rails console: + +```bash +$ bin/rails c +>> ActionController::API.ancestors - ActionController::Metal.ancestors +=> [ActionController::API, + ActiveRecord::Railties::ControllerRuntime, + ActionDispatch::Routing::RouteSet::MountedHelpers, + ActionController::ParamsWrapper, + ... , + AbstractController::Rendering, + ActionView::ViewPaths] +``` + +### Adding Other Modules + +All Action Controller modules know about their dependent modules, so you can feel +free to include any modules into your controllers, and all dependencies will be +included and set up as well. + +Some common modules you might want to add: + +- `AbstractController::Translation`: Support for the `l` and `t` localization + and translation methods. +- Support for basic, digest or token HTTP authentication: + * `ActionController::HttpAuthentication::Basic::ControllerMethods`, + * `ActionController::HttpAuthentication::Digest::ControllerMethods`, + * `ActionController::HttpAuthentication::Token::ControllerMethods` +- `ActionView::Layouts`: Support for layouts when rendering. +- `ActionController::MimeResponds`: Support for `respond_to`. +- `ActionController::Cookies`: Support for `cookies`, which includes + support for signed and encrypted cookies. This requires the cookies middleware. + +The best place to add a module is in your `ApplicationController`, but you can +also add modules to individual controllers. diff --git a/guides/source/api_documentation_guidelines.md b/guides/source/api_documentation_guidelines.md index b385bdbe83..10b89433e7 100644 --- a/guides/source/api_documentation_guidelines.md +++ b/guides/source/api_documentation_guidelines.md @@ -16,7 +16,8 @@ RDoc ---- The [Rails API documentation](http://api.rubyonrails.org) is generated with -[RDoc](http://docs.seattlerb.org/rdoc/). +[RDoc](https://ruby.github.io/rdoc/). To generate it, make sure you are +in the rails root directory, run `bundle install` and execute: ```bash bundle exec rake rdoc @@ -25,9 +26,9 @@ The [Rails API documentation](http://api.rubyonrails.org) is generated with 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), +[markup](https://ruby.github.io/rdoc/RDoc/Markup.html), and also take into account these [additional -directives](http://docs.seattlerb.org/rdoc/RDoc/Parser/Ruby.html). +directives](https://ruby.github.io/rdoc/RDoc/Parser/Ruby.html). Wording ------- @@ -81,7 +82,13 @@ used. Instead of: English ------- -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). +Please use American English (*color*, *center*, *modularize*, etc). See [a list of American and British English spelling differences here](https://en.wikipedia.org/wiki/American_and_British_English_spelling_differences). + +Oxford Comma +------------ + +Please use the [Oxford comma](https://en.wikipedia.org/wiki/Serial_comma) +("red, white, and blue", instead of "red, white and blue"). Example Code ------------ @@ -113,7 +120,7 @@ On the other hand, big chunks of structured documentation may have a separate "E The results of expressions follow them and are introduced by "# => ", vertically aligned: ```ruby -# For checking if a fixnum is even or odd. +# For checking if an integer is even or odd. # # 1.even? # => false # 1.odd? # => true @@ -233,7 +240,7 @@ You can quickly test the RDoc output with the following command: ``` $ echo "+:to_param+" | rdoc --pipe -#=> <p><code>:to_param</code></p> +# => <p><code>:to_param</code></p> ``` ### Regular Font @@ -274,7 +281,7 @@ Methods created with `(module|class)_eval(STRING)` have a comment by their side ```ruby for severity in Severity.constants - class_eval <<-EOT, __FILE__, __LINE__ + class_eval <<-EOT, __FILE__, __LINE__ + 1 def #{severity.downcase}(message = nil, progname = nil, &block) # def debug(message = nil, progname = nil, &block) add(#{severity}, message, progname, &block) # add(DEBUG, message, progname, &block) end # end @@ -326,10 +333,6 @@ As a contributor, it's important to think about whether this API is meant for en 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 @@ -347,7 +350,7 @@ into account, one such example is ```ruby # image_tag("icon.png") -# # => <img alt="Icon" src="/assets/icon.png" /> +# # => <img src="/assets/icon.png" /> ``` Although the default behavior for `#image_tag` is to always return diff --git a/guides/source/asset_pipeline.md b/guides/source/asset_pipeline.md index 9da0ef1eb3..e6d5aed135 100644 --- a/guides/source/asset_pipeline.md +++ b/guides/source/asset_pipeline.md @@ -21,22 +21,21 @@ 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 and pre-processors such as CoffeeScript, Sass and ERB. +It allows assets in your application to be automatically combined with assets +from other gems. For example, jquery-rails includes a copy of jquery.js +and enables AJAX features in Rails. -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. - -You can disable the asset pipeline while creating a new application by +The asset pipeline is implemented by the +[sprockets-rails](https://github.com/rails/sprockets-rails) gem, +and is enabled by default. You can disable it while creating a new application by passing the `--skip-sprockets` option. ```bash rails new appname --skip-sprockets ``` -Rails 4 automatically adds the `sass-rails`, `coffee-rails` and `uglifier` -gems to your Gemfile, which are used by Sprockets for asset compression: +Rails automatically adds the `sass-rails`, `coffee-rails` and `uglifier` +gems to your `Gemfile`, which are used by Sprockets for asset compression: ```ruby gem 'sass-rails' @@ -44,9 +43,9 @@ gem 'uglifier' gem 'coffee-rails' ``` -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, +Using the `--skip-sprockets` option will prevent Rails from adding +them to your `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 @@ -66,7 +65,7 @@ config.assets.js_compressor = :uglifier ``` NOTE: The `sass-rails` gem is automatically used for CSS compression if included -in Gemfile and no `config.assets.css_compressor` option is set. +in the `Gemfile` and no `config.assets.css_compressor` option is set. ### Main Features @@ -79,9 +78,9 @@ requests can mean faster loading for your application. 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. +Rails inserts an SHA256 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, @@ -107,7 +106,7 @@ 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 sprockets uses for fingerprinting is to insert a hash of the +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` ``` @@ -155,7 +154,7 @@ environments. You can enable or disable it in your configuration through the More reading: -* [Optimize caching](http://code.google.com/speed/page-speed/docs/caching.html) +* [Optimize caching](https://developers.google.com/speed/docs/insights/LeverageBrowserCaching) * [Revving Filenames: don't use querystring](http://www.stevesouders.com/blog/2008/08/23/revving-filenames-dont-use-querystring/) @@ -169,7 +168,7 @@ 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 when -`config.serve_static_files` is set to true. You should use `app/assets` for +`config.public_file_server.enabled` 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 @@ -182,7 +181,7 @@ 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 +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 @@ -203,12 +202,12 @@ will result in your assets being included more than once. 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 +default `.coffee` and `.scss` files will not be precompiled on their own. See [Precompiling Assets](#precompiling-assets) for more information on how precompiling works. 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 +If you are using macOS or Windows, you have a JavaScript runtime installed in your operating system. Check [ExecJS](https://github.com/rails/execjs#readme) documentation to know all supported JavaScript runtimes. You can also disable generation of controller specific asset files by adding the @@ -284,10 +283,10 @@ 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: +added to the pipeline in `config/initializers/assets.rb`. For example: ```ruby -config.assets.paths << Rails.root.join("lib", "videoplayer", "flash") +Rails.application.config.assets.paths << Rails.root.join("lib", "videoplayer", "flash") ``` Paths are traversed in the order they occur in the search path. By default, @@ -327,16 +326,16 @@ familiar `javascript_include_tag` and `stylesheet_link_tag`: <%= javascript_include_tag "application" %> ``` -If using the turbolinks gem, which is included by default in Rails 4, then +If using the turbolinks gem, which is included by default in Rails, 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 %> +<%= stylesheet_link_tag "application", media: "all", "data-turbolinks-track" => "reload" %> +<%= javascript_include_tag "application", "data-turbolinks-track" => "reload" %> ``` -In regular views you can access images in the `public/assets/images` directory +In regular views you can access images in the `app/assets/images` directory like this: ```erb @@ -347,9 +346,9 @@ 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 +Alternatively, a request for a file with an SHA256 hash such as +`public/assets/rails-f90d8a84c707a8dc923fca1ca1895ae8ed0a09237f6992015fef1e11be77c023.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`, @@ -384,7 +383,7 @@ it would make sense to have an image in one of the asset load paths, such as 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) - +If you want to use a [data URI](https://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. @@ -403,13 +402,13 @@ When using the asset pipeline, paths to assets must be re-written and 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"`. +* `image-url("rails.png")` returns `url(/assets/rails.png)` +* `image-path("rails.png")` returns `"/assets/rails.png"` The more generic form can also be used: -* `asset-url("rails.png")` becomes `url(/assets/rails.png)` -* `asset-path("rails.png")` becomes `"/assets/rails.png"` +* `asset-url("rails.png")` returns `url(/assets/rails.png)` +* `asset-path("rails.png")` returns `"/assets/rails.png"` #### JavaScript/CoffeeScript and ERB @@ -436,27 +435,27 @@ 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. +necessary, concatenates them into one single file and then compresses them +(based on value of `Rails.application.config.assets.js_compressor`). 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 4 application includes a default +For example, a new Rails application includes a default `app/assets/javascripts/application.js` file containing the following lines: ```js // ... -//= require jquery -//= require jquery_ujs +//= require rails-ujs +//= require turbolinks //= require_tree . ``` 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 +requiring the files `rails-ujs.js` and `turbolinks.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. @@ -484,9 +483,9 @@ which contains these lines: */ ``` -Rails 4 creates both `app/assets/javascripts/application.js` and +Rails 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 +--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 @@ -573,19 +572,18 @@ would generate this HTML: The `body` param is required by Sprockets. -### Runtime Error Checking +### Raise an Error When an Asset is Not Found -By default the asset pipeline will check for potential errors in development mode during -runtime. To disable this behavior you can set: +If you are using sprockets-rails >= 3.2.0 you can configure what happens +when an asset lookup is performed and nothing is found. If you turn off "asset fallback" +then an error will be raised when an asset cannot be found. ```ruby -config.assets.raise_runtime_errors = false +config.assets.unknown_asset_fallback = 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. +If "asset fallback" is enabled then when an asset cannot be found the path will be +output instead and no error raised. The asset fallback behavior is enabled by default. ### Turning Digests Off @@ -642,8 +640,8 @@ 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. +During the precompilation phase an SHA256 is generated from the contents of the +compiled files, and inserted into the filenames as they are written to disk. These fingerprinted names are used by the Rails helpers in place of the manifest name. @@ -662,12 +660,12 @@ generates something like this: rel="stylesheet" /> ``` -Note: with the Asset Pipeline the :cache and :concat options aren't used +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 development). +initialization option (which defaults to `true`). 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 @@ -676,7 +674,7 @@ content changes. ### Precompiling Assets -Rails comes bundled with a rake task to compile the asset manifests and other +Rails comes bundled with a task to compile the asset manifests and other files in the pipeline. Compiled assets are written to the location specified in `config.assets.prefix`. @@ -686,10 +684,10 @@ 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: +The task is: ```bash -$ RAILS_ENV=production bin/rake assets:precompile +$ RAILS_ENV=production bin/rails assets:precompile ``` Capistrano (v2.15.1 and above) includes a recipe to handle this in deployment. @@ -725,28 +723,30 @@ 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 -Rails.application.config.assets.precompile += ['admin.js', 'admin.css', 'swfObject.js'] +Rails.application.config.assets.precompile += %w( admin.js admin.css ) ``` -NOTE. Always specify an expected compiled filename that ends with .js or .css, +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-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: +The task also generates a `.sprockets-manifest-md5hash.json` (where `md5hash` is +an MD5 hash) 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: ```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"}} +{"files":{"application-aee4be71f1288037ae78b997df388332edfd246471b533dcedaa8f9fe156442b.js":{"logical_path":"application.js","mtime":"2016-12-23T20:12:03-05:00","size":412383, +"digest":"aee4be71f1288037ae78b997df388332edfd246471b533dcedaa8f9fe156442b","integrity":"sha256-ruS+cfEogDeueLmX3ziDMu39JGRxtTPc7aqPn+FWRCs="}, +"application-86a292b5070793c37e2c0e5f39f73bb387644eaeada7f96e6fc040a028b16c18.css":{"logical_path":"application.css","mtime":"2016-12-23T19:12:20-05:00","size":2994, +"digest":"86a292b5070793c37e2c0e5f39f73bb387644eaeada7f96e6fc040a028b16c18","integrity":"sha256-hqKStQcHk8N+LA5fOfc7s4dkTq6tp/lub8BAoCixbBg="}, +"favicon-8d2387b8d4d32cecd93fa3900df0e9ff89d01aacd84f50e780c17c9f6b3d0eda.ico":{"logical_path":"favicon.ico","mtime":"2016-12-23T20:11:00-05:00","size":8629, +"digest":"8d2387b8d4d32cecd93fa3900df0e9ff89d01aacd84f50e780c17c9f6b3d0eda","integrity":"sha256-jSOHuNTTLOzZP6OQDfDp/4nQGqzYT1DngMF8n2s9Dto="}, +"my_image-f4028156fd7eca03584d5f2fc0470df1e0dbc7369eaae638b2ff033f988ec493.png":{"logical_path":"my_image.png","mtime":"2016-12-23T20:10:54-05:00","size":23414, +"digest":"f4028156fd7eca03584d5f2fc0470df1e0dbc7369eaae638b2ff033f988ec493","integrity":"sha256-9AKBVv1+ygNYTV8vwEcN8eDbxzaequY4sv8DP5iOxJM="}}, +"assets":{"application.js":"application-aee4be71f1288037ae78b997df388332edfd246471b533dcedaa8f9fe156442b.js", +"application.css":"application-86a292b5070793c37e2c0e5f39f73bb387644eaeada7f96e6fc040a028b16c18.css", +"favicon.ico":"favicon-8d2387b8d4d32cecd93fa3900df0e9ff89d01aacd84f50e780c17c9f6b3d0eda.ico", +"my_image.png":"my_image-f4028156fd7eca03584d5f2fc0470df1e0dbc7369eaae638b2ff033f988ec493.png"}} ``` The default location for the manifest is the root of the location specified in @@ -786,45 +786,9 @@ location ~ ^/assets/ { add_header Cache-Control public; add_header ETag ""; - break; -} -``` - -#### 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. - -NGINX is able to do this automatically enabling `gzip_static`: - -```nginx -location ~ ^/(assets)/ { - root /path/to/public; - gzip_static on; # to serve pre-gzipped version - expires max; - add_header Cache-Control public; } ``` -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. - -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. @@ -874,7 +838,7 @@ 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. +include the SHA256 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 @@ -886,18 +850,18 @@ 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: +pre-existing JavaScript runtimes, you may want to add one to your `Gemfile`: ```ruby group :production do - gem 'therubyracer' + gem 'mini_racer' end ``` ### CDNs CDN stands for [Content Delivery -Network](http://en.wikipedia.org/wiki/Content_delivery_network), they are +Network](https://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 @@ -933,7 +897,7 @@ 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`: +`config/environments/production.rb`: ```ruby config.action_controller.asset_host = 'mycdnsubdomain.fictional-cdn.com' @@ -945,7 +909,7 @@ domain, you do not need to specify a protocol or "scheme" such as `http://` or 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 +variable](https://en.wikipedia.org/wiki/Environment_variable) to make running a staging copy of your site easier: ``` @@ -1056,15 +1020,17 @@ 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 +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 +year. You can do this in your Rails application by setting ``` -config.static_cache_control = "public, max-age=31536000" +config.public_file_server.headers = { + 'Cache-Control' => 'public, max-age=31536000' +} ``` Now when your application serves an asset in production, the CDN will store the @@ -1103,7 +1069,7 @@ Customizing the Pipeline ### CSS Compression One of the options for compressing CSS is YUI. The [YUI CSS -compressor](http://yui.github.io/yuicompressor/css.html) provides +compressor](https://yui.github.io/yuicompressor/css.html) provides minification. The following line enables YUI compression, and requires the `yui-compressor` @@ -1124,7 +1090,7 @@ 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). +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 @@ -1137,14 +1103,20 @@ config.assets.js_compressor = :uglifier ``` NOTE: You will need an [ExecJS](https://github.com/rails/execjs#readme) -supported runtime in order to use `uglifier`. If you are using Mac OS X or +supported runtime in order to use `uglifier`. If you are using macOS or Windows you have a JavaScript runtime installed in your operating system. -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. + + +### Serving GZipped version of assets + +By default, gzipped version of compiled assets will be generated, along with +the non-gzipped version of assets. Gzipped assets help reduce the transmission +of data over the wire. You can configure this by setting the `gzip` flag. + +```ruby +config.assets.gzip = false # disable gzipped assets generation +``` ### Using Your Own Compressor @@ -1210,19 +1182,14 @@ TIP: For further details have a look at the docs of your production web server: 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`: +By default, Sprockets caches assets in `tmp/cache/assets` in development +and production environments. This can be changed as follows: ```ruby -config.assets.cache_store = :memory_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.configure do |env| + env.cache = ActiveSupport::Cache.lookup_store(:memory_store, + { size: 32.megabytes }) +end ``` To disable the assets cache store: @@ -1248,35 +1215,25 @@ Sprockets. Making Your Library or Gem a Pre-Processor ------------------------------------------ -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. +Sprockets uses Processors, Transformers, Compressors, and Exporters to extend +Sprockets functionality. Have a look at +[Extending Sprockets](https://github.com/rails/sprockets/blob/master/guides/extending_sprockets.md) +to learn more. Here we registered a preprocessor to add a comment to the end +of text/css (`.css`) files. ```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 +module AddComment + def self.call(input) + { data: input[:data] + "/* Hello From my sprockets extension */" } end end ``` -Now that you have a `Template` class, it's time to associate it with an -extension for template files: +Now that you have a module that modifies the input data, it's time to register +it as a preprocessor for your mime type. ```ruby -Sprockets.register_engine '.bang', BangBang::Template +Sprockets.register_preprocessor 'text/css', AddComment ``` Upgrading from Old Versions of Rails @@ -1313,25 +1270,27 @@ config.assets.debug = true And in `production.rb`: ```ruby -# Choose the compressors to use (if any) 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. This is planned for deprecation. +# Generate digests for assets URLs. 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 ) +# non-JS/CSS are already added) +# config.assets.precompile += %w( admin.js admin.css ) ``` -Rails 4 no longer sets default config values for Sprockets in `test.rb`, so +Rails 4 and above no longer set 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`: +The following should also be added to your `Gemfile`: ```ruby gem 'sass-rails', "~> 3.2.3" diff --git a/guides/source/association_basics.md b/guides/source/association_basics.md index ec6017ff73..b5e236b790 100644 --- a/guides/source/association_basics.md +++ b/guides/source/association_basics.md @@ -16,54 +16,54 @@ After reading this guide, you will know: Why Associations? ----------------- -Why do we need associations between models? Because they make common operations simpler and easier in your code. For example, consider a simple Rails application that includes a model for customers and a model for orders. Each customer can have many orders. Without associations, the model declarations would look like this: +In Rails, an _association_ is a connection between two Active Record models. Why do we need associations between models? Because they make common operations simpler and easier in your code. For example, consider a simple Rails application that includes a model for authors and a model for books. Each author can have many books. Without associations, the model declarations would look like this: ```ruby -class Customer < ActiveRecord::Base +class Author < ApplicationRecord end -class Order < ActiveRecord::Base +class Book < ApplicationRecord end ``` -Now, suppose we wanted to add a new order for an existing customer. We'd need to do something like this: +Now, suppose we wanted to add a new book for an existing author. We'd need to do something like this: ```ruby -@order = Order.create(order_date: Time.now, customer_id: @customer.id) +@book = Book.create(published_at: Time.now, author_id: @author.id) ``` -Or consider deleting a customer, and ensuring that all of its orders get deleted as well: +Or consider deleting an author, and ensuring that all of its books get deleted as well: ```ruby -@orders = Order.where(customer_id: @customer.id) -@orders.each do |order| - order.destroy +@books = Book.where(author_id: @author.id) +@books.each do |book| + book.destroy end -@customer.destroy +@author.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 authors and books: ```ruby -class Customer < ActiveRecord::Base - has_many :orders, dependent: :destroy +class Author < ApplicationRecord + has_many :books, dependent: :destroy end -class Order < ActiveRecord::Base - belongs_to :customer +class Book < ApplicationRecord + belongs_to :author end ``` -With this change, creating a new order for a particular customer is easier: +With this change, creating a new book for a particular author is easier: ```ruby -@order = @customer.orders.create(order_date: Time.now) +@book = @author.books.create(published_at: Time.now) ``` -Deleting a customer and all of its orders is *much* easier: +Deleting an author and all of its books is *much* easier: ```ruby -@customer.destroy +@author.destroy ``` To learn more about the different types of associations, read the next section of this guide. That's followed by some tips and tricks for working with associations, and then by a complete reference to the methods and options for associations in Rails. @@ -71,7 +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: +Rails supports six types of associations: * `belongs_to` * `has_one` @@ -80,36 +80,38 @@ In Rails, an _association_ is a connection between two Active Record models. Ass * `has_one :through` * `has_and_belongs_to_many` +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](https://en.wikipedia.org/wiki/Unique_key)-[Foreign Key](https://en.wikipedia.org/wiki/Foreign_key) information between instances of the two models, and you also get a number of utility methods added to your model. + In the remainder of this guide, you'll learn how to declare and use the various forms of associations. But first, a quick introduction to the situations where each association type is appropriate. ### The `belongs_to` Association -A `belongs_to` association sets up a one-to-one connection with another model, such that each instance of the declaring model "belongs to" one instance of the other model. For example, if your application includes customers and orders, and each order can be assigned to exactly one customer, you'd declare the order model this way: +A `belongs_to` association sets up a one-to-one connection with another model, such that each instance of the declaring model "belongs to" one instance of the other model. For example, if your application includes authors and books, and each book can be assigned to exactly one author, you'd declare the book model this way: ```ruby -class Order < ActiveRecord::Base - belongs_to :customer +class Book < ApplicationRecord + belongs_to :author end ```  -NOTE: `belongs_to` associations _must_ use the singular term. If you used the pluralized form in the above example for the `customer` association in the `Order` model, you would be told that there was an "uninitialized constant Order::Customers". This is because Rails automatically infers the class name from the association name. If the association name is wrongly pluralized, then the inferred class will be wrongly pluralized too. +NOTE: `belongs_to` associations _must_ use the singular term. If you used the pluralized form in the above example for the `author` association in the `Book` model, you would be told that there was an "uninitialized constant Book::Authors". This is because Rails automatically infers the class name from the association name. If the association name is wrongly pluralized, then the inferred class will be wrongly pluralized too. The corresponding migration might look like this: ```ruby -class CreateOrders < ActiveRecord::Migration +class CreateBooks < ActiveRecord::Migration[5.0] def change - create_table :customers do |t| + create_table :authors do |t| t.string :name - t.timestamps null: false + t.timestamps end - create_table :orders do |t| - t.belongs_to :customer, index: true - t.datetime :order_date - t.timestamps null: false + create_table :books do |t| + t.belongs_to :author, index: true + t.datetime :published_at + t.timestamps end end end @@ -120,7 +122,7 @@ end A `has_one` association also sets up a one-to-one connection with another model, but with somewhat different semantics (and consequences). This association indicates that each instance of a model contains or possesses one instance of another model. For example, if each supplier in your application has only one account, you'd declare the supplier model like this: ```ruby -class Supplier < ActiveRecord::Base +class Supplier < ApplicationRecord has_one :account end ``` @@ -130,29 +132,40 @@ end The corresponding migration might look like this: ```ruby -class CreateSuppliers < ActiveRecord::Migration +class CreateSuppliers < ActiveRecord::Migration[5.0] def change create_table :suppliers do |t| t.string :name - t.timestamps null: false + t.timestamps end create_table :accounts do |t| t.belongs_to :supplier, index: true t.string :account_number - t.timestamps null: false + t.timestamps end end end ``` +Depending on the use case, you might also need to create a unique index and/or +a foreign key constraint on the supplier column for the accounts table. In this +case, the column definition might look like this: + +```ruby +create_table :accounts do |t| + t.belongs_to :supplier, index: { unique: true }, foreign_key: true + # ... +end +``` + ### The `has_many` Association -A `has_many` association indicates a one-to-many connection with another model. You'll often find this association on the "other side" of a `belongs_to` association. This association indicates that each instance of the model has zero or more instances of another model. For example, in an application containing customers and orders, the customer model could be declared like this: +A `has_many` association indicates a one-to-many connection with another model. You'll often find this association on the "other side" of a `belongs_to` association. This association indicates that each instance of the model has zero or more instances of another model. For example, in an application containing authors and books, the author model could be declared like this: ```ruby -class Customer < ActiveRecord::Base - has_many :orders +class Author < ApplicationRecord + has_many :books end ``` @@ -163,17 +176,17 @@ NOTE: The name of the other model is pluralized when declaring a `has_many` asso The corresponding migration might look like this: ```ruby -class CreateCustomers < ActiveRecord::Migration +class CreateAuthors < ActiveRecord::Migration[5.0] def change - create_table :customers do |t| + create_table :authors do |t| t.string :name - t.timestamps null: false + t.timestamps end - create_table :orders do |t| - t.belongs_to :customer, index: true - t.datetime :order_date - t.timestamps null: false + create_table :books do |t| + t.belongs_to :author, index: true + t.datetime :published_at + t.timestamps end end end @@ -184,17 +197,17 @@ end A `has_many :through` association is often used to set up a many-to-many connection with another model. This association indicates that the declaring model can be matched with zero or more instances of another model by proceeding _through_ a third model. For example, consider a medical practice where patients make appointments to see physicians. The relevant association declarations could look like this: ```ruby -class Physician < ActiveRecord::Base +class Physician < ApplicationRecord has_many :appointments has_many :patients, through: :appointments end -class Appointment < ActiveRecord::Base +class Appointment < ApplicationRecord belongs_to :physician belongs_to :patient end -class Patient < ActiveRecord::Base +class Patient < ApplicationRecord has_many :appointments has_many :physicians, through: :appointments end @@ -205,52 +218,54 @@ end The corresponding migration might look like this: ```ruby -class CreateAppointments < ActiveRecord::Migration +class CreateAppointments < ActiveRecord::Migration[5.0] def change create_table :physicians do |t| t.string :name - t.timestamps null: false + t.timestamps end create_table :patients do |t| t.string :name - t.timestamps null: false + t.timestamps end create_table :appointments do |t| t.belongs_to :physician, index: true t.belongs_to :patient, index: true t.datetime :appointment_date - t.timestamps null: false + t.timestamps end end end ``` -The collection of join models can be managed via the API. For example, if you assign +The collection of join models can be managed via the [`has_many` association methods](#has-many-association-reference). +For example, if you assign: ```ruby physician.patients = patients ``` -new join models are created for newly associated objects, and if some are gone their rows are deleted. +Then new join models are automatically created for the newly associated objects. +If some that existed previously are now missing, then their join rows are automatically deleted. WARNING: Automatic deletion of join models is direct, no destroy callbacks are triggered. The `has_many :through` association is also useful for setting up "shortcuts" through nested `has_many` associations. For example, if a document has many sections, and a section has many paragraphs, you may sometimes want to get a simple collection of all paragraphs in the document. You could set that up this way: ```ruby -class Document < ActiveRecord::Base +class Document < ApplicationRecord has_many :sections has_many :paragraphs, through: :sections end -class Section < ActiveRecord::Base +class Section < ApplicationRecord belongs_to :document has_many :paragraphs end -class Paragraph < ActiveRecord::Base +class Paragraph < ApplicationRecord belongs_to :section end ``` @@ -269,17 +284,17 @@ For example, if each supplier has one account, and each account is associated wi supplier model could look like this: ```ruby -class Supplier < ActiveRecord::Base +class Supplier < ApplicationRecord has_one :account has_one :account_history, through: :account end -class Account < ActiveRecord::Base +class Account < ApplicationRecord belongs_to :supplier has_one :account_history end -class AccountHistory < ActiveRecord::Base +class AccountHistory < ApplicationRecord belongs_to :account end ``` @@ -289,23 +304,23 @@ end The corresponding migration might look like this: ```ruby -class CreateAccountHistories < ActiveRecord::Migration +class CreateAccountHistories < ActiveRecord::Migration[5.0] def change create_table :suppliers do |t| t.string :name - t.timestamps null: false + t.timestamps end create_table :accounts do |t| t.belongs_to :supplier, index: true t.string :account_number - t.timestamps null: false + t.timestamps end create_table :account_histories do |t| t.belongs_to :account, index: true t.integer :credit_rating - t.timestamps null: false + t.timestamps end end end @@ -316,11 +331,11 @@ end A `has_and_belongs_to_many` association creates a direct many-to-many connection with another model, with no intervening model. For example, if your application includes assemblies and parts, with each assembly having many parts and each part appearing in many assemblies, you could declare the models this way: ```ruby -class Assembly < ActiveRecord::Base +class Assembly < ApplicationRecord has_and_belongs_to_many :parts end -class Part < ActiveRecord::Base +class Part < ApplicationRecord has_and_belongs_to_many :assemblies end ``` @@ -330,16 +345,16 @@ end The corresponding migration might look like this: ```ruby -class CreateAssembliesAndParts < ActiveRecord::Migration +class CreateAssembliesAndParts < ActiveRecord::Migration[5.0] def change create_table :assemblies do |t| t.string :name - t.timestamps null: false + t.timestamps end create_table :parts do |t| t.string :part_number - t.timestamps null: false + t.timestamps end create_table :assemblies_parts, id: false do |t| @@ -357,11 +372,11 @@ If you want to set up a one-to-one relationship between two models, you'll need The distinction is in where you place the foreign key (it goes on the table for the class declaring the `belongs_to` association), but you should give some thought to the actual meaning of the data as well. The `has_one` relationship says that one of something is yours - that is, that something points back to you. For example, it makes more sense to say that a supplier owns an account than that an account owns a supplier. This suggests that the correct relationships are like this: ```ruby -class Supplier < ActiveRecord::Base +class Supplier < ApplicationRecord has_one :account end -class Account < ActiveRecord::Base +class Account < ApplicationRecord belongs_to :supplier end ``` @@ -369,17 +384,17 @@ end The corresponding migration might look like this: ```ruby -class CreateSuppliers < ActiveRecord::Migration +class CreateSuppliers < ActiveRecord::Migration[5.0] def change create_table :suppliers do |t| - t.string :name - t.timestamps null: false + t.string :name + t.timestamps end create_table :accounts do |t| t.integer :supplier_id t.string :account_number - t.timestamps null: false + t.timestamps end add_index :accounts, :supplier_id @@ -394,11 +409,11 @@ NOTE: Using `t.integer :supplier_id` makes the foreign key naming obvious and ex Rails offers two different ways to declare a many-to-many relationship between models. The simpler way is to use `has_and_belongs_to_many`, which allows you to make the association directly: ```ruby -class Assembly < ActiveRecord::Base +class Assembly < ApplicationRecord has_and_belongs_to_many :parts end -class Part < ActiveRecord::Base +class Part < ApplicationRecord has_and_belongs_to_many :assemblies end ``` @@ -406,17 +421,17 @@ end The second way to declare a many-to-many relationship is to use `has_many :through`. This makes the association indirectly, through a join model: ```ruby -class Assembly < ActiveRecord::Base +class Assembly < ApplicationRecord has_many :manifests has_many :parts, through: :manifests end -class Manifest < ActiveRecord::Base +class Manifest < ApplicationRecord belongs_to :assembly belongs_to :part end -class Part < ActiveRecord::Base +class Part < ApplicationRecord has_many :manifests has_many :assemblies, through: :manifests end @@ -424,22 +439,22 @@ end The simplest rule of thumb is that you should set up a `has_many :through` relationship if you need to work with the relationship model as an independent entity. If you don't need to do anything with the relationship model, it may be simpler to set up a `has_and_belongs_to_many` relationship (though you'll need to remember to create the joining table in the database). -You should use `has_many :through` if you need validations, callbacks, or extra attributes on the join model. +You should use `has_many :through` if you need validations, callbacks or extra attributes on the join model. ### Polymorphic Associations A slightly more advanced twist on associations is the _polymorphic association_. With polymorphic associations, a model can belong to more than one other model, on a single association. For example, you might have a picture model that belongs to either an employee model or a product model. Here's how this could be declared: ```ruby -class Picture < ActiveRecord::Base +class Picture < ApplicationRecord belongs_to :imageable, polymorphic: true end -class Employee < ActiveRecord::Base +class Employee < ApplicationRecord has_many :pictures, as: :imageable end -class Product < ActiveRecord::Base +class Product < ApplicationRecord has_many :pictures, as: :imageable end ``` @@ -451,13 +466,13 @@ Similarly, you can retrieve `@product.pictures`. If you have an instance of the `Picture` model, you can get to its parent via `@picture.imageable`. To make this work, you need to declare both a foreign key column and a type column in the model that declares the polymorphic interface: ```ruby -class CreatePictures < ActiveRecord::Migration +class CreatePictures < ActiveRecord::Migration[5.0] def change create_table :pictures do |t| t.string :name t.integer :imageable_id t.string :imageable_type - t.timestamps null: false + t.timestamps end add_index :pictures, [:imageable_type, :imageable_id] @@ -468,12 +483,12 @@ end This migration can be simplified by using the `t.references` form: ```ruby -class CreatePictures < ActiveRecord::Migration +class CreatePictures < ActiveRecord::Migration[5.0] def change create_table :pictures do |t| t.string :name t.references :imageable, polymorphic: true, index: true - t.timestamps null: false + t.timestamps end end end @@ -486,7 +501,7 @@ end In designing a data model, you will sometimes find a model that should have a relation to itself. For example, you may want to store all employees in a single database model, but be able to trace relationships such as between manager and subordinates. This situation can be modeled with self-joining associations: ```ruby -class Employee < ActiveRecord::Base +class Employee < ApplicationRecord has_many :subordinates, class_name: "Employee", foreign_key: "manager_id" @@ -499,11 +514,11 @@ With this setup, you can retrieve `@employee.subordinates` and `@employee.manage In your migrations/schema, you will add a references column to the model itself. ```ruby -class CreateEmployees < ActiveRecord::Migration +class CreateEmployees < ActiveRecord::Migration[5.0] def change create_table :employees do |t| t.references :manager, index: true - t.timestamps null: false + t.timestamps end end end @@ -525,18 +540,18 @@ Here are a few things you should know to make efficient use of Active Record ass All of the association methods are built around caching, which keeps the result of the most recent query available for further operations. The cache is even shared across methods. For example: ```ruby -customer.orders # retrieves orders from the database -customer.orders.size # uses the cached copy of orders -customer.orders.empty? # uses the cached copy of orders +author.books # retrieves books from the database +author.books.size # uses the cached copy of books +author.books.empty? # uses the cached copy of books ``` -But what if you want to reload the cache, because data might have been changed by some other part of the application? Just pass `true` to the association call: +But what if you want to reload the cache, because data might have been changed by some other part of the application? Just call `reload` on the association: ```ruby -customer.orders # retrieves orders from the database -customer.orders.size # uses the cached copy of orders -customer.orders(true).empty? # discards the cached copy of orders - # and goes back to the database +author.books # retrieves books from the database +author.books.size # uses the cached copy of books +author.books.reload.empty? # discards the cached copy of books + # and goes back to the database ``` ### Avoiding Name Collisions @@ -552,43 +567,59 @@ Associations are extremely useful, but they are not magic. You are responsible f When you declare a `belongs_to` association, you need to create foreign keys as appropriate. For example, consider this model: ```ruby -class Order < ActiveRecord::Base - belongs_to :customer +class Book < ApplicationRecord + belongs_to :author end ``` -This declaration needs to be backed up by the proper foreign key declaration on the orders table: +This declaration needs to be backed up by the proper foreign key declaration on the books table: ```ruby -class CreateOrders < ActiveRecord::Migration +class CreateBooks < ActiveRecord::Migration[5.0] def change - create_table :orders do |t| - t.datetime :order_date - t.string :order_number - t.integer :customer_id + create_table :books do |t| + t.datetime :published_at + t.string :book_number + t.integer :author_id end - - add_index :orders, :customer_id end end ``` If you create an association some time after you build the underlying model, you need to remember to create an `add_column` migration to provide the necessary foreign key. +It's a good practice to add an index on the foreign key to improve queries +performance and a foreign key constraint to ensure referential data integrity: + +```ruby +class CreateBooks < ActiveRecord::Migration[5.0] + def change + create_table :books do |t| + t.datetime :published_at + t.string :book_number + t.integer :author_id + end + + add_index :books, :author_id + add_foreign_key :books, :authors + end +end +``` + #### Creating Join Tables for `has_and_belongs_to_many` Associations -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. +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 book of the class names. So a join between author and book models will give the default join table name of "authors_books" because "a" outranks "b" 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: ```ruby -class Assembly < ActiveRecord::Base +class Assembly < ApplicationRecord has_and_belongs_to_many :parts end -class Part < ActiveRecord::Base +class Part < ApplicationRecord has_and_belongs_to_many :assemblies end ``` @@ -596,7 +627,7 @@ 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 CreateAssembliesPartsJoinTable < ActiveRecord::Migration +class CreateAssembliesPartsJoinTable < ActiveRecord::Migration[5.0] def change create_table :assemblies_parts, id: false do |t| t.integer :assembly_id @@ -609,7 +640,20 @@ class CreateAssembliesPartsJoinTable < ActiveRecord::Migration end ``` -We pass `id: false` to `create_table` because that table does not represent a model. That's required for the association to work properly. If you observe any strange behavior in a `has_and_belongs_to_many` association like mangled models IDs, or exceptions about conflicting IDs, chances are you forgot that bit. +We pass `id: false` to `create_table` because that table does not represent a model. That's required for the association to work properly. If you observe any strange behavior in a `has_and_belongs_to_many` association like mangled model IDs, or exceptions about conflicting IDs, chances are you forgot that bit. + +You can also use the method `create_join_table` + +```ruby +class CreateAssembliesPartsJoinTable < ActiveRecord::Migration[5.0] + def change + create_join_table :assemblies, :parts do |t| + t.index :assembly_id + t.index :part_id + end + end +end +``` ### Controlling Association Scope @@ -618,12 +662,12 @@ By default, associations look for objects only within the current module's scope ```ruby module MyApplication module Business - class Supplier < ActiveRecord::Base - has_one :account + class Supplier < ApplicationRecord + has_one :account end - class Account < ActiveRecord::Base - belongs_to :supplier + class Account < ApplicationRecord + belongs_to :supplier end end end @@ -634,14 +678,14 @@ This will work fine, because both the `Supplier` and the `Account` class are def ```ruby module MyApplication module Business - class Supplier < ActiveRecord::Base - has_one :account + class Supplier < ApplicationRecord + has_one :account end end module Billing - class Account < ActiveRecord::Base - belongs_to :supplier + class Account < ApplicationRecord + belongs_to :supplier end end end @@ -652,15 +696,15 @@ To associate a model with a model in a different namespace, you must specify the ```ruby module MyApplication module Business - class Supplier < ActiveRecord::Base - has_one :account, + class Supplier < ApplicationRecord + has_one :account, class_name: "MyApplication::Billing::Account" end end module Billing - class Account < ActiveRecord::Base - belongs_to :supplier, + class Account < ApplicationRecord + belongs_to :supplier, class_name: "MyApplication::Business::Supplier" end end @@ -672,64 +716,82 @@ end It's normal for associations to work in two directions, requiring declaration on two different models: ```ruby -class Customer < ActiveRecord::Base - has_many :orders +class Author < ApplicationRecord + has_many :books +end + +class Book < ApplicationRecord + belongs_to :author +end +``` + +Active Record will attempt to automatically identify that these two models share a bi-directional association based on the association name. In this way, Active Record will only load one copy of the `Author` object, making your application more efficient and preventing inconsistent data: + +```ruby +a = Author.first +b = a.books.first +a.first_name == b.author.first_name # => true +a.first_name = 'David' +a.first_name == b.author.first_name # => true +``` + +Active Record supports automatic identification for most associations with standard names. However, Active Record will not automatically identify bi-directional associations that contain any of the following options: + +* `:conditions` +* `:through` +* `:polymorphic` +* `:class_name` +* `:foreign_key` + +For example, consider the following model declarations: + +```ruby +class Author < ApplicationRecord + has_many :books end -class Order < ActiveRecord::Base - belongs_to :customer +class Book < ApplicationRecord + belongs_to :writer, class_name: 'Author', foreign_key: 'author_id' end ``` -By default, Active Record doesn't know about the connection between these associations. This can lead to two copies of an object getting out of sync: +Active Record will no longer automatically recognize the bi-directional association: ```ruby -c = Customer.first -o = c.orders.first -c.first_name == o.customer.first_name # => true -c.first_name = 'Manny' -c.first_name == o.customer.first_name # => false +a = Author.first +b = a.books.first +a.first_name == b.writer.first_name # => true +a.first_name = 'David' +a.first_name == b.writer.first_name # => false ``` -This happens because `c` and `o.customer` are two different in-memory representations of the same data, and neither one is automatically refreshed from changes to the other. Active Record provides the `:inverse_of` option so that you can inform it of these relations: +Active Record provides the `:inverse_of` option so you can explicitly declare bi-directional associations: ```ruby -class Customer < ActiveRecord::Base - has_many :orders, inverse_of: :customer +class Author < ApplicationRecord + has_many :books, inverse_of: 'writer' end -class Order < ActiveRecord::Base - belongs_to :customer, inverse_of: :orders +class Book < ApplicationRecord + belongs_to :writer, class_name: 'Author', foreign_key: 'author_id' end ``` -With these changes, Active Record will only load one copy of the customer object, preventing inconsistencies and making your application more efficient: +By including the `:inverse_of` option in the `has_many` association declaration, Active Record will now recognize the bi-directional association: ```ruby -c = Customer.first -o = c.orders.first -c.first_name == o.customer.first_name # => true -c.first_name = 'Manny' -c.first_name == o.customer.first_name # => true +a = Author.first +b = a.books.first +a.first_name == b.writer.first_name # => true +a.first_name = 'David' +a.first_name == b.writer.first_name # => true ``` -There are a few limitations to `inverse_of` support: +There are a few limitations to `:inverse_of` support: * They do not work with `:through` associations. * They do not work with `:polymorphic` associations. * 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 ------------------------------ @@ -744,48 +806,54 @@ The `belongs_to` association creates a one-to-one match with another model. In d When you declare a `belongs_to` association, the declaring class automatically gains five methods related to the association: -* `association(force_reload = false)` +* `association` * `association=(associate)` * `build_association(attributes = {})` * `create_association(attributes = {})` * `create_association!(attributes = {})` +* `reload_association` In all of these methods, `association` is replaced with the symbol passed as the first argument to `belongs_to`. For example, given the declaration: ```ruby -class Order < ActiveRecord::Base - belongs_to :customer +class Book < ApplicationRecord + belongs_to :author end ``` -Each instance of the `Order` model will have these methods: +Each instance of the `Book` model will have these methods: ```ruby -customer -customer= -build_customer -create_customer -create_customer! +author +author= +build_author +create_author +create_author! +reload_author ``` 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. -##### `association(force_reload = false)` +##### `association` The `association` method returns the associated object, if any. If no associated object is found, it returns `nil`. ```ruby -@customer = @order.customer +@author = @book.author ``` -If the associated object has already been retrieved from the database for this object, the cached version will be returned. To override this behavior (and force a database read), pass `true` as the `force_reload` argument. +If the associated object has already been retrieved from the database for this object, the cached version will be returned. To override this behavior (and force a database read), call `#reload_association` on the parent object. + +```ruby +@author = @book.reload_author +``` ##### `association=(associate)` -The `association=` method assigns an associated object to this object. Behind the scenes, this means extracting the primary key from the associate object and setting this object's foreign key to the same value. +The `association=` method assigns an associated object to this object. Behind the scenes, this means extracting the primary key from the associated object and setting this object's foreign key to the same value. ```ruby -@order.customer = @customer +@book.author = @author ``` ##### `build_association(attributes = {})` @@ -793,8 +861,8 @@ The `association=` method assigns an associated object to this object. Behind th The `build_association` method returns a new object of the associated type. This object will be instantiated from the passed attributes, and the link through this object's foreign key will be set, but the associated object will _not_ yet be saved. ```ruby -@customer = @order.build_customer(customer_number: 123, - customer_name: "John Doe") +@author = @book.build_author(author_number: 123, + author_name: "John Doe") ``` ##### `create_association(attributes = {})` @@ -802,8 +870,8 @@ The `build_association` method returns a new object of the associated type. This The `create_association` method returns a new object of the associated type. This object will be instantiated from the passed attributes, the link through this object's foreign key will be set, and, once it passes all of the validations specified on the associated model, the associated object _will_ be saved. ```ruby -@customer = @order.create_customer(customer_number: 123, - customer_name: "John Doe") +@author = @book.create_author(author_number: 123, + author_name: "John Doe") ``` ##### `create_association!(attributes = {})` @@ -816,8 +884,8 @@ Does the same as `create_association` above, but raises `ActiveRecord::RecordInv 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 `belongs_to` association reference. Such customizations can easily be accomplished by passing options and scope blocks when you create the association. For example, this association uses two such options: ```ruby -class Order < ActiveRecord::Base - belongs_to :customer, dependent: :destroy, +class Book < ApplicationRecord + belongs_to :author, dependent: :destroy, counter_cache: true end ``` @@ -829,6 +897,7 @@ The `belongs_to` association supports these options: * `:counter_cache` * `:dependent` * `:foreign_key` +* `:primary_key` * `:inverse_of` * `:polymorphic` * `:touch` @@ -837,15 +906,15 @@ The `belongs_to` association supports these options: ##### `:autosave` -If you set the `:autosave` option to `true`, Rails will save any loaded members and destroy members that are marked for destruction whenever you save the parent object. +If you set the `:autosave` option to `true`, Rails will save any loaded association members and destroy members that are marked for destruction whenever you save the parent object. Setting `:autosave` to `false` is not the same as not setting the `:autosave` option. If the `:autosave` option is not present, then new associated objects will be saved, but updated associated objects will not be saved. ##### `:class_name` -If the name of the other model cannot be derived from the association name, you can use the `:class_name` option to supply the model name. For example, if an order belongs to a customer, but the actual name of the model containing customers is `Patron`, you'd set things up this way: +If the name of the other model cannot be derived from the association name, you can use the `:class_name` option to supply the model name. For example, if a book belongs to an author, but the actual name of the model containing authors is `Patron`, you'd set things up this way: ```ruby -class Order < ActiveRecord::Base - belongs_to :customer, class_name: "Patron" +class Book < ApplicationRecord + belongs_to :author, class_name: "Patron" end ``` @@ -854,39 +923,47 @@ end The `:counter_cache` option can be used to make finding the number of belonging objects more efficient. Consider these models: ```ruby -class Order < ActiveRecord::Base - belongs_to :customer +class Book < ApplicationRecord + belongs_to :author end -class Customer < ActiveRecord::Base - has_many :orders +class Author < ApplicationRecord + has_many :books end ``` -With these declarations, asking for the value of `@customer.orders.size` requires making a call to the database to perform a `COUNT(*)` query. To avoid this call, you can add a counter cache to the _belonging_ model: +With these declarations, asking for the value of `@author.books.size` requires making a call to the database to perform a `COUNT(*)` query. To avoid this call, you can add a counter cache to the _belonging_ model: ```ruby -class Order < ActiveRecord::Base - belongs_to :customer, counter_cache: true +class Book < ApplicationRecord + belongs_to :author, counter_cache: true end -class Customer < ActiveRecord::Base - has_many :orders +class Author < ApplicationRecord + has_many :books end ``` With this declaration, Rails will keep the cache value up to date, and then return that value in response to the `size` method. -Although the `:counter_cache` option is specified on the model that includes the `belongs_to` declaration, the actual column must be added to the _associated_ model. In the case above, you would need to add a column named `orders_count` to the `Customer` model. You can override the default column name if you need to: +Although the `:counter_cache` option is specified on the model that includes +the `belongs_to` declaration, the actual column must be added to the +_associated_ (`has_many`) model. In the case above, you would need to add a +column named `books_count` to the `Author` model. + +You can override the default column name by specifying a custom column name in +the `counter_cache` declaration instead of `true`. For example, to use +`count_of_books` instead of `books_count`: ```ruby -class Order < ActiveRecord::Base - belongs_to :customer, counter_cache: :count_of_orders +class Book < ApplicationRecord + belongs_to :author, counter_cache: :count_of_books end -class Customer < ActiveRecord::Base - has_many :orders, counter_cache: :count_of_orders +class Author < ApplicationRecord + has_many :books 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. +NOTE: You only need to specify the `:counter_cache` option on the `belongs_to` +side of the association. Counter cache columns are added to the containing model's list of read-only attributes through `attr_readonly`. @@ -905,25 +982,45 @@ WARNING: You should not specify this option on a `belongs_to` association that i By convention, Rails assumes that the column used to hold the foreign key on this model is the name of the association with the suffix `_id` added. The `:foreign_key` option lets you set the name of the foreign key directly: ```ruby -class Order < ActiveRecord::Base - belongs_to :customer, class_name: "Patron", +class Book < ApplicationRecord + belongs_to :author, class_name: "Patron", foreign_key: "patron_id" end ``` TIP: In any case, Rails will not create foreign key columns for you. You need to explicitly define them as part of your migrations. +##### `:primary_key` + +By convention, Rails assumes that the `id` column is used to hold the primary key +of its tables. The `:primary_key` option allows you to specify a different column. + +For example, given we have a `users` table with `guid` as the primary key. If we want a separate `todos` table to hold the foreign key `user_id` in the `guid` column, then we can use `primary_key` to achieve this like so: + +```ruby +class User < ApplicationRecord + self.primary_key = 'guid' # primary key is guid and not id +end + +class Todo < ApplicationRecord + belongs_to :user, primary_key: 'guid' +end +``` + +When we execute `@user.todos.create` then the `@todo` record will have its +`user_id` value as the `guid` value of `@user`. + ##### `:inverse_of` The `:inverse_of` option specifies the name of the `has_many` or `has_one` association that is the inverse of this association. Does not work in combination with the `:polymorphic` options. ```ruby -class Customer < ActiveRecord::Base - has_many :orders, inverse_of: :customer +class Author < ApplicationRecord + has_many :books, inverse_of: :author end -class Order < ActiveRecord::Base - belongs_to :customer, inverse_of: :orders +class Book < ApplicationRecord + belongs_to :author, inverse_of: :books end ``` @@ -936,20 +1033,20 @@ Passing `true` to the `:polymorphic` option indicates that this is a polymorphic If you set the `:touch` option to `true`, then the `updated_at` or `updated_on` timestamp on the associated object will be set to the current time whenever this object is saved or destroyed: ```ruby -class Order < ActiveRecord::Base - belongs_to :customer, touch: true +class Book < ApplicationRecord + belongs_to :author, touch: true end -class Customer < ActiveRecord::Base - has_many :orders +class Author < ApplicationRecord + has_many :books end ``` -In this case, saving or destroying an order will update the timestamp on the associated customer. You can also specify a particular timestamp attribute to update: +In this case, saving or destroying a book will update the timestamp on the associated author. You can also specify a particular timestamp attribute to update: ```ruby -class Order < ActiveRecord::Base - belongs_to :customer, touch: :orders_updated_at +class Book < ApplicationRecord + belongs_to :author, touch: :books_updated_at end ``` @@ -967,8 +1064,8 @@ object won't be validated. By default, this option is set to `false`. There may be times when you wish to customize the query used by `belongs_to`. Such customizations can be achieved via a scope block. For example: ```ruby -class Order < ActiveRecord::Base - belongs_to :customer, -> { where active: true }, +class Book < ApplicationRecord + belongs_to :author, -> { where active: true }, dependent: :destroy end ``` @@ -985,8 +1082,8 @@ You can use any of the standard [querying methods](active_record_querying.html) The `where` method lets you specify the conditions that the associated object must meet. ```ruby -class Order < ActiveRecord::Base - belongs_to :customer, -> { where active: true } +class book < ApplicationRecord + belongs_to :author, -> { where active: true } end ``` @@ -995,38 +1092,38 @@ end 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 - belongs_to :order +class LineItem < ApplicationRecord + belongs_to :book end -class Order < ActiveRecord::Base - belongs_to :customer +class Book < ApplicationRecord + belongs_to :author has_many :line_items end -class Customer < ActiveRecord::Base - has_many :orders +class Author < ApplicationRecord + has_many :books end ``` -If you frequently retrieve customers directly from line items (`@line_item.order.customer`), then you can make your code somewhat more efficient by including customers in the association from line items to orders: +If you frequently retrieve authors directly from line items (`@line_item.book.author`), then you can make your code somewhat more efficient by including authors in the association from line items to books: ```ruby -class LineItem < ActiveRecord::Base - belongs_to :order, -> { includes :customer } +class LineItem < ApplicationRecord + belongs_to :book, -> { includes :author } end -class Order < ActiveRecord::Base - belongs_to :customer +class Book < ApplicationRecord + belongs_to :author has_many :line_items end -class Customer < ActiveRecord::Base - has_many :orders +class Author < ApplicationRecord + has_many :books end ``` -NOTE: There's no need to use `includes` for immediate associations - that is, if you have `Order belongs_to :customer`, then the customer is eager-loaded automatically when it's needed. +NOTE: There's no need to use `includes` for immediate associations - that is, if you have `Book belongs_to :author`, then the author is eager-loaded automatically when it's needed. ##### `readonly` @@ -1043,8 +1140,8 @@ TIP: If you use the `select` method on a `belongs_to` association, you should al You can see if any associated objects exist by using the `association.nil?` method: ```ruby -if @order.customer.nil? - @msg = "No customer found for this order" +if @book.author.nil? + @msg = "No author found for this book" end ``` @@ -1060,16 +1157,17 @@ The `has_one` association creates a one-to-one match with another model. In data When you declare a `has_one` association, the declaring class automatically gains five methods related to the association: -* `association(force_reload = false)` +* `association` * `association=(associate)` * `build_association(attributes = {})` * `create_association(attributes = {})` * `create_association!(attributes = {})` +* `reload_association` In all of these methods, `association` is replaced with the symbol passed as the first argument to `has_one`. For example, given the declaration: ```ruby -class Supplier < ActiveRecord::Base +class Supplier < ApplicationRecord has_one :account end ``` @@ -1082,11 +1180,12 @@ account= build_account create_account create_account! +reload_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. -##### `association(force_reload = false)` +##### `association` The `association` method returns the associated object, if any. If no associated object is found, it returns `nil`. @@ -1094,11 +1193,15 @@ The `association` method returns the associated object, if any. If no associated @account = @supplier.account ``` -If the associated object has already been retrieved from the database for this object, the cached version will be returned. To override this behavior (and force a database read), pass `true` as the `force_reload` argument. +If the associated object has already been retrieved from the database for this object, the cached version will be returned. To override this behavior (and force a database read), call `#reload_association` on the parent object. + +```ruby +@account = @supplier.reload_account +``` ##### `association=(associate)` -The `association=` method assigns an associated object to this object. Behind the scenes, this means extracting the primary key from this object and setting the associate object's foreign key to the same value. +The `association=` method assigns an associated object to this object. Behind the scenes, this means extracting the primary key from this object and setting the associated object's foreign key to the same value. ```ruby @supplier.account = @account @@ -1129,7 +1232,7 @@ Does the same as `create_association` above, but raises `ActiveRecord::RecordInv 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: ```ruby -class Supplier < ActiveRecord::Base +class Supplier < ApplicationRecord has_one :account, class_name: "Billing", dependent: :nullify end ``` @@ -1154,14 +1257,14 @@ Setting the `:as` option indicates that this is a polymorphic association. Polym ##### `:autosave` -If you set the `:autosave` option to `true`, Rails will save any loaded members and destroy members that are marked for destruction whenever you save the parent object. +If you set the `:autosave` option to `true`, Rails will save any loaded association members and destroy members that are marked for destruction whenever you save the parent object. Setting `:autosave` to `false` is not the same as not setting the `:autosave` option. If the `:autosave` option is not present, then new associated objects will be saved, but updated associated objects will not be saved. ##### `:class_name` If the name of the other model cannot be derived from the association name, you can use the `:class_name` option to supply the model name. For example, if a supplier has an account, but the actual name of the model containing accounts is `Billing`, you'd set things up this way: ```ruby -class Supplier < ActiveRecord::Base +class Supplier < ApplicationRecord has_one :account, class_name: "Billing" end ``` @@ -1179,15 +1282,15 @@ Controls what happens to the associated object when its owner is destroyed: 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. +because the initial associated object's foreign key will be set to the +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: ```ruby -class Supplier < ActiveRecord::Base +class Supplier < ApplicationRecord has_one :account, foreign_key: "supp_id" end ``` @@ -1199,11 +1302,11 @@ TIP: In any case, Rails will not create foreign key columns for you. You need to The `:inverse_of` option specifies the name of the `belongs_to` association that is the inverse of this association. Does not work in combination with the `:through` or `:as` options. ```ruby -class Supplier < ActiveRecord::Base +class Supplier < ApplicationRecord has_one :account, inverse_of: :supplier end -class Account < ActiveRecord::Base +class Account < ApplicationRecord belongs_to :supplier, inverse_of: :account end ``` @@ -1233,7 +1336,7 @@ If you set the `:validate` option to `true`, then associated objects will be val There may be times when you wish to customize the query used by `has_one`. Such customizations can be achieved via a scope block. For example: ```ruby -class Supplier < ActiveRecord::Base +class Supplier < ApplicationRecord has_one :account, -> { where active: true } end ``` @@ -1250,7 +1353,7 @@ You can use any of the standard [querying methods](active_record_querying.html) The `where` method lets you specify the conditions that the associated object must meet. ```ruby -class Supplier < ActiveRecord::Base +class Supplier < ApplicationRecord has_one :account, -> { where "confirmed = 1" } end ``` @@ -1260,16 +1363,16 @@ end 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 Supplier < ActiveRecord::Base +class Supplier < ApplicationRecord has_one :account end -class Account < ActiveRecord::Base +class Account < ApplicationRecord belongs_to :supplier belongs_to :representative end -class Representative < ActiveRecord::Base +class Representative < ApplicationRecord has_many :accounts end ``` @@ -1277,16 +1380,16 @@ end If you frequently retrieve representatives directly from suppliers (`@supplier.account.representative`), then you can make your code somewhat more efficient by including representatives in the association from suppliers to accounts: ```ruby -class Supplier < ActiveRecord::Base +class Supplier < ApplicationRecord has_one :account, -> { includes :representative } end -class Account < ActiveRecord::Base +class Account < ApplicationRecord belongs_to :supplier belongs_to :representative end -class Representative < ActiveRecord::Base +class Representative < ApplicationRecord has_many :accounts end ``` @@ -1317,7 +1420,7 @@ If either of these saves fails due to validation errors, then the assignment sta If the parent object (the one declaring the `has_one` association) is unsaved (that is, `new_record?` returns `true`) then the child objects are not saved. They will automatically when the parent object is saved. -If you want to assign an object to a `has_one` association without saving the object, use the `association.build` method. +If you want to assign an object to a `has_one` association without saving the object, use the `build_association` method. ### `has_many` Association Reference @@ -1327,7 +1430,7 @@ The `has_many` association creates a one-to-many relationship with another model When you declare a `has_many` association, the declaring class automatically gains 16 methods related to the association: -* `collection(force_reload = false)` +* `collection` * `collection<<(object, ...)` * `collection.delete(object, ...)` * `collection.destroy(object, ...)` @@ -1343,42 +1446,44 @@ When you declare a `has_many` association, the declaring class automatically gai * `collection.build(attributes = {}, ...)` * `collection.create(attributes = {})` * `collection.create!(attributes = {})` +* `collection.reload` 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: ```ruby -class Customer < ActiveRecord::Base - has_many :orders +class Author < ApplicationRecord + has_many :books end ``` -Each instance of the `Customer` model will have these methods: +Each instance of the `Author` model will have these methods: ```ruby -orders(force_reload = false) -orders<<(object, ...) -orders.delete(object, ...) -orders.destroy(object, ...) -orders=(objects) -order_ids -order_ids=(ids) -orders.clear -orders.empty? -orders.size -orders.find(...) -orders.where(...) -orders.exists?(...) -orders.build(attributes = {}, ...) -orders.create(attributes = {}) -orders.create!(attributes = {}) +books +books<<(object, ...) +books.delete(object, ...) +books.destroy(object, ...) +books=(objects) +book_ids +book_ids=(ids) +books.clear +books.empty? +books.size +books.find(...) +books.where(...) +books.exists?(...) +books.build(attributes = {}, ...) +books.create(attributes = {}) +books.create!(attributes = {}) +books.reload ``` -##### `collection(force_reload = false)` +##### `collection` -The `collection` method returns an array of all of the associated objects. If there are no associated objects, it returns an empty array. +The `collection` method returns a Relation of all of the associated objects. If there are no associated objects, it returns an empty Relation. ```ruby -@orders = @customer.orders +@books = @author.books ``` ##### `collection<<(object, ...)` @@ -1386,7 +1491,7 @@ The `collection` method returns an array of all of the associated objects. If th The `collection<<` method adds one or more objects to the collection by setting their foreign keys to the primary key of the calling model. ```ruby -@customer.orders << @order1 +@author.books << @book1 ``` ##### `collection.delete(object, ...)` @@ -1394,7 +1499,7 @@ The `collection<<` method adds one or more objects to the collection by setting The `collection.delete` method removes one or more objects from the collection by setting their foreign keys to `NULL`. ```ruby -@customer.orders.delete(@order1) +@author.books.delete(@book1) ``` WARNING: Additionally, objects will be destroyed if they're associated with `dependent: :destroy`, and deleted if they're associated with `dependent: :delete_all`. @@ -1404,38 +1509,45 @@ WARNING: Additionally, objects will be destroyed if they're associated with `dep The `collection.destroy` method removes one or more objects from the collection by running `destroy` on each object. ```ruby -@customer.orders.destroy(@order1) +@author.books.destroy(@book1) ``` WARNING: Objects will _always_ be removed from the database, ignoring the `:dependent` option. ##### `collection=(objects)` -The `collection=` method makes the collection contain only the supplied objects, by adding and deleting as appropriate. +The `collection=` method makes the collection contain only the supplied objects, by adding and deleting as appropriate. The changes are persisted to the database. ##### `collection_singular_ids` The `collection_singular_ids` method returns an array of the ids of the objects in the collection. ```ruby -@order_ids = @customer.order_ids +@book_ids = @author.book_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. +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. The changes are persisted to the database. ##### `collection.clear` -The `collection.clear` method removes every object from the collection. This destroys the associated objects if they are associated with `dependent: :destroy`, deletes them directly from the database if `dependent: :delete_all`, and otherwise sets their foreign keys to `NULL`. +The `collection.clear` method removes all objects from the collection according to the strategy specified by the `dependent` option. If no option is given, it follows the default strategy. The default strategy for `has_many :through` associations is `delete_all`, and for `has_many` associations is to set the foreign keys to `NULL`. + +```ruby +@author.books.clear +``` + +WARNING: Objects will be deleted if they're associated with `dependent: :destroy`, +just like `dependent: :delete_all`. ##### `collection.empty?` The `collection.empty?` method returns `true` if the collection does not contain any associated objects. ```erb -<% if @customer.orders.empty? %> - No Orders Found +<% if @author.books.empty? %> + No Books Found <% end %> ``` @@ -1444,15 +1556,16 @@ The `collection.empty?` method returns `true` if the collection does not contain The `collection.size` method returns the number of objects in the collection. ```ruby -@order_count = @customer.orders.size +@book_count = @author.books.size ``` ##### `collection.find(...)` -The `collection.find` method finds objects within the collection. It uses the same syntax and options as `ActiveRecord::Base.find`. +The `collection.find` method finds objects within the collection. It uses the same syntax and options as +[`ActiveRecord::Base.find`](http://api.rubyonrails.org/classes/ActiveRecord/FinderMethods.html#method-i-find). ```ruby -@open_orders = @customer.orders.find(1) +@available_book = @author.books.find(1) ``` ##### `collection.where(...)` @@ -1460,43 +1573,63 @@ The `collection.find` method finds objects within the collection. It uses the sa The `collection.where` method finds objects within the collection based on the conditions supplied but the objects are loaded lazily meaning that the database is queried only when the object(s) are accessed. ```ruby -@open_orders = @customer.orders.where(open: true) # No query yet -@open_order = @open_orders.first # Now the database will be queried +@available_books = @author.books.where(available: true) # No query yet +@available_book = @available_books.first # Now the database will be queried ``` ##### `collection.exists?(...)` -The `collection.exists?` method checks whether an object meeting the supplied conditions exists in the collection. It uses the same syntax and options as `ActiveRecord::Base.exists?`. +The `collection.exists?` method checks whether an object meeting the supplied +conditions exists in the collection. It uses the same syntax and options as +[`ActiveRecord::Base.exists?`](http://api.rubyonrails.org/classes/ActiveRecord/FinderMethods.html#method-i-exists-3F). ##### `collection.build(attributes = {}, ...)` -The `collection.build` method returns one or more new objects of the associated type. These objects will be instantiated from the passed attributes, and the link through their foreign key will be created, but the associated objects will _not_ yet be saved. +The `collection.build` method returns a single or array of new objects of the associated type. The object(s) will be instantiated from the passed attributes, and the link through their foreign key will be created, but the associated objects will _not_ yet be saved. ```ruby -@order = @customer.orders.build(order_date: Time.now, - order_number: "A12345") +@book = @author.books.build(published_at: Time.now, + book_number: "A12345") + +@books = @author.books.build([ + { published_at: Time.now, book_number: "A12346" }, + { published_at: Time.now, book_number: "A12347" } +]) ``` ##### `collection.create(attributes = {})` -The `collection.create` method returns a new object of the associated type. This object will be instantiated from the passed attributes, the link through its foreign key will be created, and, once it passes all of the validations specified on the associated model, the associated object _will_ be saved. +The `collection.create` method returns a single or array of new objects of the associated type. The object(s) will be instantiated from the passed attributes, the link through its foreign key will be created, and, once it passes all of the validations specified on the associated model, the associated object _will_ be saved. ```ruby -@order = @customer.orders.create(order_date: Time.now, - order_number: "A12345") +@book = @author.books.create(published_at: Time.now, + book_number: "A12345") + +@books = @author.books.create([ + { published_at: Time.now, book_number: "A12346" }, + { published_at: Time.now, book_number: "A12347" } +]) ``` ##### `collection.create!(attributes = {})` Does the same as `collection.create` above, but raises `ActiveRecord::RecordInvalid` if the record is invalid. +##### `collection.reload` + +The `collection.reload` method returns a Relation of all of the associated objects, forcing a database read. If there are no associated objects, it returns an empty Relation. + +```ruby +@books = @author.books.reload +``` + #### 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: ```ruby -class Customer < ActiveRecord::Base - has_many :orders, dependent: :delete_all, validate: false +class Author < ApplicationRecord + has_many :books, dependent: :delete_all, validate: false end ``` @@ -1521,15 +1654,15 @@ Setting the `:as` option indicates that this is a polymorphic association, as di ##### `:autosave` -If you set the `:autosave` option to `true`, Rails will save any loaded members and destroy members that are marked for destruction whenever you save the parent object. +If you set the `:autosave` option to `true`, Rails will save any loaded association members and destroy members that are marked for destruction whenever you save the parent object. Setting `:autosave` to `false` is not the same as not setting the `:autosave` option. If the `:autosave` option is not present, then new associated objects will be saved, but updated associated objects will not be saved. ##### `:class_name` -If the name of the other model cannot be derived from the association name, you can use the `:class_name` option to supply the model name. For example, if a customer has many orders, but the actual name of the model containing orders is `Transaction`, you'd set things up this way: +If the name of the other model cannot be derived from the association name, you can use the `:class_name` option to supply the model name. For example, if an author has many books, but the actual name of the model containing books is `Transaction`, you'd set things up this way: ```ruby -class Customer < ActiveRecord::Base - has_many :orders, class_name: "Transaction" +class Author < ApplicationRecord + has_many :books, class_name: "Transaction" end ``` @@ -1552,8 +1685,8 @@ Controls what happens to the associated objects when their owner is destroyed: 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: ```ruby -class Customer < ActiveRecord::Base - has_many :orders, foreign_key: "cust_id" +class Author < ApplicationRecord + has_many :books, foreign_key: "cust_id" end ``` @@ -1564,12 +1697,12 @@ TIP: In any case, Rails will not create foreign key columns for you. You need to The `:inverse_of` option specifies the name of the `belongs_to` association that is the inverse of this association. Does not work in combination with the `:through` or `:as` options. ```ruby -class Customer < ActiveRecord::Base - has_many :orders, inverse_of: :customer +class Author < ApplicationRecord + has_many :books, inverse_of: :author end -class Order < ActiveRecord::Base - belongs_to :customer, inverse_of: :orders +class Book < ApplicationRecord + belongs_to :author, inverse_of: :books end ``` @@ -1577,18 +1710,19 @@ 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 +Let's say the `users` table has `id` as the primary_key but it also +has a `guid` column. The requirement is that the `todos` table should +hold the `guid` column value as the foreign key and not `id` +value. This can be achieved like this: ```ruby -class User < ActiveRecord::Base +class User < ApplicationRecord 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`. +Now if we execute `@todo = @user.todos.create` then the `@todo` +record's `user_id` value will be the `guid` value of `@user`. ##### `:source` @@ -1612,8 +1746,8 @@ If you set the `:validate` option to `false`, then associated objects will not b There may be times when you wish to customize the query used by `has_many`. Such customizations can be achieved via a scope block. For example: ```ruby -class Customer < ActiveRecord::Base - has_many :orders, -> { where processed: true } +class Author < ApplicationRecord + has_many :books, -> { where processed: true } end ``` @@ -1628,29 +1762,29 @@ You can use any of the standard [querying methods](active_record_querying.html) * `order` * `readonly` * `select` -* `uniq` +* `distinct` ##### `where` The `where` method lets you specify the conditions that the associated object must meet. ```ruby -class Customer < ActiveRecord::Base - has_many :confirmed_orders, -> { where "confirmed = 1" }, - class_name: "Order" +class Author < ApplicationRecord + has_many :confirmed_books, -> { where "confirmed = 1" }, + class_name: "Book" end ``` You can also set conditions via a hash: ```ruby -class Customer < ActiveRecord::Base - has_many :confirmed_orders, -> { where confirmed: true }, - class_name: "Order" +class Author < ApplicationRecord + has_many :confirmed_books, -> { where confirmed: true }, + class_name: "Book" end ``` -If you use a hash-style `where` option, then record creation via this association will be automatically scoped using the hash. In this case, using `@customer.confirmed_orders.create` or `@customer.confirmed_orders.build` will create orders where the confirmed column has the value `true`. +If you use a hash-style `where` option, then record creation via this association will be automatically scoped using the hash. In this case, using `@author.confirmed_books.create` or `@author.confirmed_books.build` will create books where the confirmed column has the value `true`. ##### `extending` @@ -1661,9 +1795,9 @@ The `extending` method specifies a named module to extend the association proxy. The `group` method supplies an attribute name to group the result set by, using a `GROUP BY` clause in the finder SQL. ```ruby -class Customer < ActiveRecord::Base - has_many :line_items, -> { group 'orders.id' }, - through: :orders +class Author < ApplicationRecord + has_many :line_items, -> { group 'books.id' }, + through: :books end ``` @@ -1672,34 +1806,34 @@ end 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 Customer < ActiveRecord::Base - has_many :orders +class Author < ApplicationRecord + has_many :books end -class Order < ActiveRecord::Base - belongs_to :customer +class Book < ApplicationRecord + belongs_to :author has_many :line_items end -class LineItem < ActiveRecord::Base - belongs_to :order +class LineItem < ApplicationRecord + belongs_to :book end ``` -If you frequently retrieve line items directly from customers (`@customer.orders.line_items`), then you can make your code somewhat more efficient by including line items in the association from customers to orders: +If you frequently retrieve line items directly from authors (`@author.books.line_items`), then you can make your code somewhat more efficient by including line items in the association from authors to books: ```ruby -class Customer < ActiveRecord::Base - has_many :orders, -> { includes :line_items } +class Author < ApplicationRecord + has_many :books, -> { includes :line_items } end -class Order < ActiveRecord::Base - belongs_to :customer +class Book < ApplicationRecord + belongs_to :author has_many :line_items end -class LineItem < ActiveRecord::Base - belongs_to :order +class LineItem < ApplicationRecord + belongs_to :book end ``` @@ -1708,10 +1842,10 @@ end The `limit` method lets you restrict the total number of objects that will be fetched through an association. ```ruby -class Customer < ActiveRecord::Base - has_many :recent_orders, - -> { order('order_date desc').limit(100) }, - class_name: "Order", +class Author < ApplicationRecord + has_many :recent_books, + -> { order('published_at desc').limit(100) }, + class_name: "Book" end ``` @@ -1724,8 +1858,8 @@ The `offset` method lets you specify the starting offset for fetching objects vi The `order` method dictates the order in which associated objects will be received (in the syntax used by an SQL `ORDER BY` clause). ```ruby -class Customer < ActiveRecord::Base - has_many :orders, -> { order "date_confirmed DESC" } +class Author < ApplicationRecord + has_many :books, -> { order "date_confirmed DESC" } end ``` @@ -1745,7 +1879,7 @@ 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 +class Person < ApplicationRecord has_many :readings has_many :articles, through: :readings end @@ -1755,7 +1889,7 @@ 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>] +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.articles` brings out both of @@ -1774,7 +1908,7 @@ 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>] +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 @@ -1784,11 +1918,21 @@ 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: +`readings` and you want to make sure the articles can only be added to a person once, +you could add the following in a migration: + +```ruby +add_index :readings, [:person_id, :article_id], unique: true +``` + +Once you have this unique index, attempting to add the article to a person twice +will raise an `ActiveRecord::RecordNotUnique` error: ```ruby -add_index :person_articles, :article, unique: true +person = Person.create(name: 'Honda') +article = Article.create(name: 'a1') +person.articles << article +person.articles << article # => ActiveRecord::RecordNotUnique ``` Note that checking for uniqueness using something like `include?` is subject @@ -1819,7 +1963,7 @@ The `has_and_belongs_to_many` association creates a many-to-many relationship wi 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` * `collection<<(object, ...)` * `collection.delete(object, ...)` * `collection.destroy(object, ...)` @@ -1835,11 +1979,12 @@ When you declare a `has_and_belongs_to_many` association, the declaring class au * `collection.build(attributes = {})` * `collection.create(attributes = {})` * `collection.create!(attributes = {})` +* `collection.reload` 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: ```ruby -class Part < ActiveRecord::Base +class Part < ApplicationRecord has_and_belongs_to_many :assemblies end ``` @@ -1847,7 +1992,7 @@ end Each instance of the `Part` model will have these methods: ```ruby -assemblies(force_reload = false) +assemblies assemblies<<(object, ...) assemblies.delete(object, ...) assemblies.destroy(object, ...) @@ -1863,6 +2008,7 @@ assemblies.exists?(...) assemblies.build(attributes = {}, ...) assemblies.create(attributes = {}) assemblies.create!(attributes = {}) +assemblies.reload ``` ##### Additional Column Methods @@ -1872,9 +2018,9 @@ If the join table for a `has_and_belongs_to_many` association has additional col WARNING: The use of extra attributes on the join table in a `has_and_belongs_to_many` association is deprecated. If you require this sort of complex behavior on the table that joins two models in a many-to-many relationship, you should use a `has_many :through` association instead of `has_and_belongs_to_many`. -##### `collection(force_reload = false)` +##### `collection` -The `collection` method returns an array of all of the associated objects. If there are no associated objects, it returns an empty array. +The `collection` method returns a Relation of all of the associated objects. If there are no associated objects, it returns an empty Relation. ```ruby @assemblies = @part.assemblies @@ -1898,11 +2044,9 @@ The `collection.delete` method removes one or more objects from the collection b @part.assemblies.delete(@assembly1) ``` -WARNING: This does not trigger callbacks on the join records. - ##### `collection.destroy(object, ...)` -The `collection.destroy` method removes one or more objects from the collection by running `destroy` on each record in the join table, including running callbacks. This does not destroy the objects. +The `collection.destroy` method removes one or more objects from the collection by deleting records in the join table. This does not destroy the objects. ```ruby @part.assemblies.destroy(@assembly1) @@ -1910,7 +2054,7 @@ The `collection.destroy` method removes one or more objects from the collection ##### `collection=(objects)` -The `collection=` method makes the collection contain only the supplied objects, by adding and deleting as appropriate. +The `collection=` method makes the collection contain only the supplied objects, by adding and deleting as appropriate. The changes are persisted to the database. ##### `collection_singular_ids` @@ -1922,7 +2066,7 @@ The `collection_singular_ids` method returns an array of the ids of the objects ##### `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. +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. The changes are persisted to the database. ##### `collection.clear` @@ -1948,7 +2092,8 @@ The `collection.size` method returns the number of objects in the collection. ##### `collection.find(...)` -The `collection.find` method finds objects within the collection. It uses the same syntax and options as `ActiveRecord::Base.find`. It also adds the additional condition that the object must be in the collection. +The `collection.find` method finds objects within the collection. It uses the same syntax and options as +[`ActiveRecord::Base.find`](http://api.rubyonrails.org/classes/ActiveRecord/FinderMethods.html#method-i-find). ```ruby @assembly = @part.assemblies.find(1) @@ -1956,7 +2101,7 @@ The `collection.find` method finds objects within the collection. It uses the sa ##### `collection.where(...)` -The `collection.where` method finds objects within the collection based on the conditions supplied but the objects are loaded lazily meaning that the database is queried only when the object(s) are accessed. It also adds the additional condition that the object must be in the collection. +The `collection.where` method finds objects within the collection based on the conditions supplied but the objects are loaded lazily meaning that the database is queried only when the object(s) are accessed. ```ruby @new_assemblies = @part.assemblies.where("created_at > ?", 2.days.ago) @@ -1964,7 +2109,9 @@ The `collection.where` method finds objects within the collection based on the c ##### `collection.exists?(...)` -The `collection.exists?` method checks whether an object meeting the supplied conditions exists in the collection. It uses the same syntax and options as `ActiveRecord::Base.exists?`. +The `collection.exists?` method checks whether an object meeting the supplied +conditions exists in the collection. It uses the same syntax and options as +[`ActiveRecord::Base.exists?`](http://api.rubyonrails.org/classes/ActiveRecord/FinderMethods.html#method-i-exists-3F). ##### `collection.build(attributes = {})` @@ -1986,12 +2133,20 @@ The `collection.create` method returns a new object of the associated type. This Does the same as `collection.create`, but raises `ActiveRecord::RecordInvalid` if the record is invalid. +##### `collection.reload` + +The `collection.reload` method returns a Relation of all of the associated objects, forcing a database read. If there are no associated objects, it returns an empty Relation. + +```ruby +@assemblies = @part.assemblies.reload +``` + #### 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 +class Parts < ApplicationRecord has_and_belongs_to_many :assemblies, -> { readonly }, autosave: true end @@ -2013,7 +2168,7 @@ By convention, Rails assumes that the column in the join table used to hold the TIP: The `:foreign_key` and `:association_foreign_key` options are useful when setting up a many-to-many self-join. For example: ```ruby -class User < ActiveRecord::Base +class User < ApplicationRecord has_and_belongs_to_many :friends, class_name: "User", foreign_key: "this_user_id", @@ -2023,14 +2178,14 @@ end ##### `:autosave` -If you set the `:autosave` option to `true`, Rails will save any loaded members and destroy members that are marked for destruction whenever you save the parent object. +If you set the `:autosave` option to `true`, Rails will save any loaded association members and destroy members that are marked for destruction whenever you save the parent object. Setting `:autosave` to `false` is not the same as not setting the `:autosave` option. If the `:autosave` option is not present, then new associated objects will be saved, but updated associated objects will not be saved. ##### `:class_name` If the name of the other model cannot be derived from the association name, you can use the `:class_name` option to supply the model name. For example, if a part has many assemblies, but the actual name of the model containing assemblies is `Gadget`, you'd set things up this way: ```ruby -class Parts < ActiveRecord::Base +class Parts < ApplicationRecord has_and_belongs_to_many :assemblies, class_name: "Gadget" end ``` @@ -2040,7 +2195,7 @@ end By convention, Rails assumes that the column in the join table used to hold the foreign key pointing to this 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: ```ruby -class User < ActiveRecord::Base +class User < ApplicationRecord has_and_belongs_to_many :friends, class_name: "User", foreign_key: "this_user_id", @@ -2061,7 +2216,7 @@ If you set the `:validate` option to `false`, then associated objects will not b There may be times when you wish to customize the query used by `has_and_belongs_to_many`. Such customizations can be achieved via a scope block. For example: ```ruby -class Parts < ActiveRecord::Base +class Parts < ApplicationRecord has_and_belongs_to_many :assemblies, -> { where active: true } end ``` @@ -2077,14 +2232,14 @@ You can use any of the standard [querying methods](active_record_querying.html) * `order` * `readonly` * `select` -* `uniq` +* `distinct` ##### `where` The `where` method lets you specify the conditions that the associated object must meet. ```ruby -class Parts < ActiveRecord::Base +class Parts < ApplicationRecord has_and_belongs_to_many :assemblies, -> { where "factory = 'Seattle'" } end @@ -2093,7 +2248,7 @@ end You can also set conditions via a hash: ```ruby -class Parts < ActiveRecord::Base +class Parts < ApplicationRecord has_and_belongs_to_many :assemblies, -> { where factory: 'Seattle' } end @@ -2110,7 +2265,7 @@ The `extending` method specifies a named module to extend the association proxy. The `group` method supplies an attribute name to group the result set by, using a `GROUP BY` clause in the finder SQL. ```ruby -class Parts < ActiveRecord::Base +class Parts < ApplicationRecord has_and_belongs_to_many :assemblies, -> { group "factory" } end ``` @@ -2124,7 +2279,7 @@ You can use the `includes` method to specify second-order associations that shou The `limit` method lets you restrict the total number of objects that will be fetched through an association. ```ruby -class Parts < ActiveRecord::Base +class Parts < ApplicationRecord has_and_belongs_to_many :assemblies, -> { order("created_at DESC").limit(50) } end @@ -2139,7 +2294,7 @@ The `offset` method lets you specify the starting offset for fetching objects vi The `order` method dictates the order in which associated objects will be received (in the syntax used by an SQL `ORDER BY` clause). ```ruby -class Parts < ActiveRecord::Base +class Parts < ApplicationRecord has_and_belongs_to_many :assemblies, -> { order "assembly_name ASC" } end @@ -2153,9 +2308,9 @@ If you use the `readonly` method, then the associated objects will be read-only The `select` method lets you override the SQL `SELECT` clause that is used to retrieve data about the associated objects. By default, Rails retrieves all columns. -##### `uniq` +##### `distinct` -Use the `uniq` method to remove duplicates from the collection. +Use the `distinct` method to remove duplicates from the collection. #### When are Objects Saved? @@ -2181,10 +2336,10 @@ Association callbacks are similar to normal callbacks, but they are triggered by You define association callbacks by adding options to the association declaration. For example: ```ruby -class Customer < ActiveRecord::Base - has_many :orders, before_add: :check_credit_limit +class Author < ApplicationRecord + has_many :books, before_add: :check_credit_limit - def check_credit_limit(order) + def check_credit_limit(book) ... end end @@ -2195,15 +2350,15 @@ Rails passes the object being added or removed to the callback. You can stack callbacks on a single event by passing them as an array: ```ruby -class Customer < ActiveRecord::Base - has_many :orders, +class Author < ApplicationRecord + has_many :books, before_add: [:check_credit_limit, :calculate_shipping_charges] - def check_credit_limit(order) + def check_credit_limit(book) ... end - def calculate_shipping_charges(order) + def calculate_shipping_charges(book) ... end end @@ -2216,10 +2371,10 @@ If a `before_add` callback throws an exception, the object does not get added to You're not limited to the functionality that Rails automatically builds into association proxy objects. You can also extend these objects through anonymous modules, adding new finders, creators, or other methods. For example: ```ruby -class Customer < ActiveRecord::Base - has_many :orders do - def find_by_order_prefix(order_number) - find_by(region_id: order_number[0..2]) +class Author < ApplicationRecord + has_many :books do + def find_by_book_prefix(book_number) + find_by(category_id: book_number[0..2]) end end end @@ -2234,11 +2389,11 @@ module FindRecentExtension end end -class Customer < ActiveRecord::Base - has_many :orders, -> { extending FindRecentExtension } +class Author < ApplicationRecord + has_many :books, -> { extending FindRecentExtension } end -class Supplier < ActiveRecord::Base +class Supplier < ApplicationRecord has_many :deliveries, -> { extending FindRecentExtension } end ``` @@ -2292,13 +2447,13 @@ associations, public methods, etc. Creating a car will save it in the `vehicles` table with "Car" as the `type` field: ```ruby -Car.create color: 'Red', price: 10000 +Car.create(color: 'Red', price: 10000) ``` will generate the following SQL: ```sql -INSERT INTO "vehicles" ("type", "color", "price") VALUES ("Car", "Red", 10000) +INSERT INTO "vehicles" ("type", "color", "price") VALUES ('Car', 'Red', 10000) ``` Querying car records will just search for vehicles that are cars: diff --git a/guides/source/autoloading_and_reloading_constants.md b/guides/source/autoloading_and_reloading_constants.md index c6149abcba..dea87a18f8 100644 --- a/guides/source/autoloading_and_reloading_constants.md +++ b/guides/source/autoloading_and_reloading_constants.md @@ -181,14 +181,14 @@ constant. That is, ```ruby -class Project < ActiveRecord::Base +class Project < ApplicationRecord end ``` performs a constant assignment equivalent to ```ruby -Project = Class.new(ActiveRecord::Base) +Project = Class.new(ApplicationRecord) ``` including setting the name of the class as a side-effect: @@ -330,11 +330,17 @@ its resolution next. Let's define *parent* to be 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. +1. The constant is looked up in the parent and its ancestors. In Ruby >= 2.5, +`Object` is skipped if present among the ancestors. `Kernel` and `BasicObject` +are still checked though. 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. +INFO. In Ruby < 2.5 `String::Hash` evaluates to `Hash` and the interpreter +issues a warning: "toplevel constant Hash referenced by String::Hash". Starting +with 2.5, `String::Hash` raises `NameError` because `Object` is skipped. + 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** @@ -449,9 +455,10 @@ 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`. +* All subdirectories of `app` in the application and engines present at boot + time. 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. @@ -466,9 +473,7 @@ by adding this to `config/application.rb`: config.autoload_paths << "#{Rails.root}/lib" ``` -`config.autoload_paths` is accessible from environment-specific configuration -files, but any changes made to it outside `config/application.rb` don't have any -effect. +`config.autoload_paths` is not changeable from environment-specific configuration files. The value of `autoload_paths` can be inspected. In a just generated application it is (edited): @@ -476,12 +481,21 @@ it is (edited): ``` $ bin/rails r 'puts ActiveSupport::Dependencies.autoload_paths' .../app/assets +.../app/channels .../app/controllers +.../app/controllers/concerns .../app/helpers +.../app/jobs .../app/mailers .../app/models -.../app/controllers/concerns .../app/models/concerns +.../activestorage/app/assets +.../activestorage/app/controllers +.../activestorage/app/javascript +.../activestorage/app/jobs +.../activestorage/app/models +.../actioncable/app/assets +.../actionview/app/assets .../test/mailers/previews ``` @@ -526,7 +540,7 @@ 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, +First it 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`. @@ -626,7 +640,7 @@ file is loaded. If the file actually defines `Post` all is fine, otherwise ### 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 +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 @@ -687,7 +701,7 @@ 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. +define 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 @@ -792,7 +806,7 @@ 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 +For example, if you're in a console session and edit some file behind the scenes, the code can be reloaded with the `reload!` command: ``` @@ -914,7 +928,7 @@ these classes: ```ruby # app/models/polygon.rb -class Polygon < ActiveRecord::Base +class Polygon < ApplicationRecord end # app/models/triangle.rb @@ -946,7 +960,7 @@ 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. +for. Let's see an example. `Rectangle.all` only loads rectangles by adding a type constraint to the query: @@ -955,7 +969,7 @@ SELECT "polygons".* FROM "polygons" WHERE "polygons"."type" IN ("Rectangle") ``` -Let’s introduce now a subclass of `Rectangle`: +Let's introduce now a subclass of `Rectangle`: ```ruby # app/models/square.rb @@ -970,7 +984,7 @@ 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` +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, @@ -984,20 +998,19 @@ 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: +manually load the direct subclasses at the bottom of the file that defines each +intermediate class: ```ruby -# app/models/polygon.rb -class Polygon < ActiveRecord::Base +# app/models/rectangle.rb +class Rectangle < Polygon end -require_dependency ‘square’ +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. +This needs to happen for every intermediate (non-root and non-leaf) class. The +root class does not scope the query by type, and therefore does not necessarily +have to know all its descendants. ### Autoloading and `require` @@ -1042,7 +1055,7 @@ 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 +`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? @@ -1171,6 +1184,8 @@ end #### Qualified References +WARNING. This gotcha is only possible in Ruby < 2.5. + Given ```ruby diff --git a/guides/source/caching_with_rails.md b/guides/source/caching_with_rails.md index 716beb9178..780e69c146 100644 --- a/guides/source/caching_with_rails.md +++ b/guides/source/caching_with_rails.md @@ -1,14 +1,26 @@ **DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON http://guides.rubyonrails.org.** -Caching with Rails: An overview +Caching with Rails: An Overview =============================== -This guide will teach you what you need to know about avoiding that expensive round-trip to your database and returning what you need to return to the web clients in the shortest time possible. +This guide is an introduction to speeding up your Rails application with caching. + +Caching means to store content generated during the request-response cycle and +to reuse it when responding to similar requests. + +Caching is often the most effective way to boost an application's performance. +Through caching, web sites running on a single server with a single database +can sustain a load of thousands of concurrent users. + +Rails provides a set of caching features out of the box. This guide will teach +you the scope and purpose of each one of them. Master these techniques and your +Rails applications can serve millions of views without exorbitant response times +or server bills. After reading this guide, you will know: -* Page and action caching (moved to separate gems as of Rails 4). -* Fragment caching. +* Fragment and Russian doll caching. +* How to manage the caching dependencies. * Alternative cache stores. * Conditional GET support. @@ -18,19 +30,32 @@ Basic Caching ------------- This is an introduction to three types of caching techniques: page, action and -fragment caching. Rails provides by default fragment caching. In order to use -page and action caching, you will need to add `actionpack-page_caching` and -`actionpack-action_caching` to your Gemfile. +fragment caching. By default Rails provides fragment caching. In order to use +page and action caching you will need to add `actionpack-page_caching` and +`actionpack-action_caching` to your `Gemfile`. -To start playing with caching you'll want to ensure that `config.action_controller.perform_caching` is set to `true`, if you're running in development mode. This flag is normally set in the corresponding `config/environments/*.rb` and caching is disabled by default for development and test, and enabled for production. +By default, caching is only enabled in your production environment. To play +around with caching locally you'll want to enable caching in your local +environment by setting `config.action_controller.perform_caching` to `true` in +the relevant `config/environments/*.rb` file: ```ruby config.action_controller.perform_caching = true ``` +NOTE: Changing the value of `config.action_controller.perform_caching` will +only have an effect on the caching provided by the Action Controller component. +For instance, it will not impact low-level caching, that we address +[below](#low-level-caching). + ### 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. +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 having to go +through the entire Rails stack. While this is super fast it can't be applied to +every situation (such as pages that need authentication). Also, because the +webserver is serving a file directly from the filesystem you will need to +implement cache expiration. INFO: Page Caching has been removed from Rails 4. See the [actionpack-page_caching gem](https://github.com/rails/actionpack-page_caching). @@ -42,116 +67,233 @@ INFO: Action Caching has been removed from Rails 4. See the [actionpack-action_c ### Fragment Caching -Life would be perfect if we could get away with caching the entire contents of a page or action and serving it out to the world. Unfortunately, dynamic web applications usually build pages with a variety of components not all of which have the same caching characteristics. In order to address such a dynamically created page where different parts of the page need to be cached and expired differently, Rails provides a mechanism called Fragment Caching. +Dynamic web applications usually build pages with a variety of components not +all of which have the same caching characteristics. When different parts of the +page need to be cached and expired separately you can use Fragment Caching. Fragment Caching allows a fragment of view logic to be wrapped in a cache block and served out of the cache store when the next request comes in. -As an example, if you wanted to show all the orders placed on your website in real time and didn't want to cache that part of the page, but did want to cache the part of the page which lists all products available, you could use this piece of code: +For example, if you wanted to cache each product on a page, you could use this +code: ```html+erb -<% Order.find_recent.each do |o| %> - <%= o.buyer.name %> bought <%= o.product.name %> +<% @products.each do |product| %> + <% cache product do %> + <%= render product %> + <% end %> <% end %> +``` -<% cache do %> - All available products: - <% Product.all.each do |p| %> - <%= link_to p.name, product_url(p) %> - <% end %> +When your application receives its first request to this page, Rails will write +a new cache entry with a unique key. A key looks something like this: + +``` +views/products/1-201505056193031061005000/bea67108094918eeba42cd4a6e786901 +``` + +The number in the middle is the `product_id` followed by the timestamp value in +the `updated_at` attribute of the product record. Rails uses the timestamp value +to make sure it is not serving stale data. If the value of `updated_at` has +changed, a new key will be generated. Then Rails will write a new cache to that +key, and the old cache written to the old key will never be used again. This is +called key-based expiration. + +Cache fragments will also be expired when the view fragment changes (e.g., the +HTML in the view changes). The string of characters at the end of the key is a +template tree digest. It is an MD5 hash computed based on the contents of the +view fragment you are caching. If you change the view fragment, the MD5 hash +will change, expiring the existing file. + +TIP: Cache stores like Memcached will automatically delete old cache files. + +If you want to cache a fragment under certain conditions, you can use +`cache_if` or `cache_unless`: + +```erb +<% cache_if admin?, product do %> + <%= render product %> <% end %> ``` -The cache block in our example will bind to the action that called it and is written out to the same place as the Action Cache, which means that if you want to cache multiple fragments per action, you should provide an `action_suffix` to the cache call: +#### Collection caching + +The `render` helper can also cache individual templates rendered for a collection. +It can even one up the previous example with `each` by reading all cache +templates at once instead of one by one. This is done by passing `cached: true` when rendering the collection: ```html+erb -<% cache(action: 'recent', action_suffix: 'all_products') do %> - All available products: +<%= render partial: 'products/product', collection: @products, cached: true %> ``` -and you can expire it using the `expire_fragment` method, like so: +All cached templates from previous renders will be fetched at once with much +greater speed. Additionally, the templates that haven't yet been cached will be +written to cache and multi fetched on the next render. -```ruby -expire_fragment(controller: 'products', action: 'recent', action_suffix: 'all_products') + +### Russian Doll Caching + +You may want to nest cached fragments inside other cached fragments. This is +called Russian doll caching. + +The advantage of Russian doll caching is that if a single product is updated, +all the other inner fragments can be reused when regenerating the outer +fragment. + +As explained in the previous section, a cached file will expire if the value of +`updated_at` changes for a record on which the cached file directly depends. +However, this will not expire any cache the fragment is nested within. + +For example, take the following view: + +```erb +<% cache product do %> + <%= render product.games %> +<% end %> ``` -If you don't want the cache block to bind to the action that called it, you can also use globally keyed fragments by calling the `cache` method with a key: +Which in turn renders this view: ```erb -<% cache('all_available_products') do %> - All available products: +<% cache game do %> + <%= render game %> <% end %> ``` -This fragment is then available to all actions in the `ProductsController` using the key and can be expired the same way: +If any attribute of game is changed, the `updated_at` value will be set to the +current time, thereby expiring the cache. However, because `updated_at` +will not be changed for the product object, that cache will not be expired and +your app will serve stale data. To fix this, we tie the models together with +the `touch` method: + +```ruby +class Product < ApplicationRecord + has_many :games +end + +class Game < ApplicationRecord + belongs_to :product, touch: true +end +``` + +With `touch` set to `true`, any action which changes `updated_at` for a game +record will also change it for the associated product, thereby expiring the +cache. + +### Shared Partial Caching + +It is possible to share partials and associated caching between files with different mime types. For example shared partial caching allows template writers to share a partial between HTML and JavaScript files. When templates are collected in the template resolver file paths they only include the template language extension and not the mime type. Because of this templates can be used for multiple mime types. Both HTML and JavaScript requests will respond to the following code: ```ruby -expire_fragment('all_available_products') +render(partial: 'hotels/hotel', collection: @hotels, cached: true) ``` -If you want to avoid expiring the fragment manually, whenever an action updates a product, you can define a helper method: + +Will load a file named `hotels/hotel.erb`. + +Another option is to include the full filename of the partial to render. ```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 +render(partial: 'hotels/hotel.html.erb', collection: @hotels, cached: true) ``` -This method generates a cache key that depends on all products and can be used in the view: +Will load a file named `hotels/hotel.html.erb` in any file mime type, for example you could include this partial in a JavaScript file. -```erb -<% cache(cache_key_for_products) do %> - All available products: -<% end %> +### Managing dependencies + +In order to correctly invalidate the cache, you need to properly define the +caching dependencies. Rails is clever enough to handle common cases so you don't +have to specify anything. However, sometimes, when you're dealing with custom +helpers for instance, you need to explicitly define them. + +#### Implicit dependencies + +Most template dependencies can be derived from calls to `render` in the template +itself. Here are some examples of render calls that `ActionView::Digestor` knows +how to decode: + +```ruby +render partial: "comments/comment", collection: commentable.comments +render "comments/comments" +render 'comments/comments' +render('comments/comments') + +render "header" translates to render("comments/header") + +render(@topic) translates to render("topics/topic") +render(topics) translates to render("topics/topic") +render(message.topics) translates to render("topics/topic") ``` -If you want to cache a fragment under certain conditions, you can use `cache_if` or `cache_unless` +On the other hand, some calls need to be changed to make caching work properly. +For instance, if you're passing a custom collection, you'll need to change: -```erb -<% cache_if (condition, cache_key_for_products) do %> - All available products: -<% end %> +```ruby +render @project.documents.where(published: true) ``` -You can also use an Active Record model as the cache key: +to: -```erb -<% Product.all.each do |p| %> - <% cache(p) do %> - <%= link_to p.name, product_url(p) %> - <% end %> -<% end %> +```ruby +render partial: "documents/document", collection: @project.documents.where(published: true) ``` -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. +#### Explicit dependencies -You can also combine the two schemes which is called "Russian Doll Caching": +Sometimes you'll have template dependencies that can't be derived at all. This +is typically the case when rendering happens in helpers. Here's an example: -```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 %> +```html+erb +<%= render_sortable_todolists @project.todolists %> +``` + +You'll need to use a special comment format to call those out: + +```html+erb +<%# Template Dependency: todolists/todolist %> +<%= render_sortable_todolists @project.todolists %> +``` + +In some cases, like a single table inheritance setup, you might have a bunch of +explicit dependencies. Instead of writing every template out, you can use a +wildcard to match any template in a directory: + +```html+erb +<%# Template Dependency: events/* %> +<%= render_categorizable_events @person.events %> +``` + +As for collection caching, if the partial template doesn't start with a clean +cache call, you can still benefit from collection caching by adding a special +comment format anywhere in the template, like: + +```html+erb +<%# Template Collection: notification %> +<% my_helper_that_calls_cache(some_arg, notification) do %> + <%= notification.name %> <% 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. +#### External dependencies + +If you use a helper method, for example, inside a cached block and you then update +that helper, you'll have to bump the cache as well. It doesn't really matter how +you do it, but the MD5 of the template file must change. One recommendation is to +simply be explicit in a comment, like: + +```html+erb +<%# Helper Dependency Updated: Jul 28, 2015 at 7pm %> +<%= some_helper_method(person) %> +``` ### 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. +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. +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, that block will be executed in the event of a cache miss. The return value of the block will be written to the cache under the given cache key, and that return value will be returned. In case of cache hit, the cached value will be returned without executing the block. -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: +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 +class Product < ApplicationRecord def competing_price Rails.cache.fetch("#{cache_key}/competing_price", expires_in: 12.hours) do Competitor::API.find_price(id) @@ -160,11 +302,14 @@ class Product < ActiveRecord::Base 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. +NOTE: Notice that in this example we used the `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 -Query caching is a Rails feature that caches the result set returned by each query so that if Rails encounters the same query again for that request, it will use the cached result set as opposed to running the query against the database again. +Query caching is a Rails feature that caches the result set returned by each +query. If Rails encounters the same query again for that request, it will use +the cached result set as opposed to running the query against the database +again. For example: @@ -186,21 +331,25 @@ 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. +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 with low level caching. Cache Stores ------------ -Rails provides different stores for the cached data created by **action** and **fragment** caches. - -TIP: Page caches are always stored on disk. +Rails provides different stores for the cached data (apart from SQL and page +caching). ### Configuration -You can set up your application's default cache store by calling `config.cache_store=` in the Application definition inside your `config/application.rb` file or in an Application.configure block in an environment specific configuration file (i.e. `config/environments/*.rb`). The first argument will be the cache store to use and the rest of the argument will be passed as arguments to the cache store constructor. +You can set up your application's default cache store by setting the +`config.cache_store` configuration option. Other parameters can be passed as +arguments to the cache store's constructor: ```ruby -config.cache_store = :memory_store +config.cache_store = :memory_store, { size: 64.megabytes } ``` NOTE: Alternatively, you can call `ActionController::Base.cache_store` outside of a configuration block. @@ -217,23 +366,49 @@ There are some common options used by all cache implementations. These can be pa * `: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. +* `:compress` - Enabled by default. Compresses cache entries so more data can be stored in the same memory footprint, leading to fewer cache evictions and higher hit rates. -* `:compress_threshold` - This options is used in conjunction with the `:compress` option to indicate a threshold under which cache entries should not be compressed. This defaults to 16 kilobytes. +* `:compress_threshold` - Defaults to 1kB. Cache entries larger than this threshold, specified in bytes, are compressed. * `:expires_in` - This option sets an expiration time in seconds for the cache entry when it will be automatically removed from the cache. * `:race_condition_ttl` - This option is used in conjunction with the `:expires_in` option. It will prevent race conditions when cache entries expire by preventing multiple processes from simultaneously regenerating the same entry (also known as the dog pile effect). This option sets the number of seconds that an expired entry can be reused while a new value is being regenerated. It's a good practice to set this value if you use the `:expires_in` option. +#### Custom Cache Stores + +You can create your own custom cache store by simply extending +`ActiveSupport::Cache::Store` and implementing the appropriate methods. This way, +you can swap in any number of caching technologies into your Rails application. + +To use a custom cache store, simply set the cache store to a new instance of your +custom class. + +```ruby +config.cache_store = MyCacheStore.new +``` + ### ActiveSupport::Cache::MemoryStore -This cache store keeps entries in memory in the same Ruby process. The cache store has a bounded size specified by the `:size` options to the initializer (default is 32Mb). When the cache exceeds the allotted size, a cleanup will occur and the least recently used entries will be removed. +This cache store keeps entries in memory in the same Ruby process. The cache +store has a bounded size specified by sending the `:size` option to the +initializer (default is 32Mb). When the cache exceeds the allotted size, a +cleanup will occur and the least recently used entries will be removed. ```ruby config.cache_store = :memory_store, { size: 64.megabytes } ``` -If you're running multiple Ruby on Rails server processes (which is the case if you're using mongrel_cluster or Phusion Passenger), then your Rails server process instances won't be able to share cache data with each other. This cache store is not appropriate for large application deployments, but can work well for small, low traffic sites with only a couple of server processes or for development and test environments. +If you're running multiple Ruby on Rails server processes (which is the case +if you're using Phusion Passenger or puma clustered mode), then your Rails server +process instances won't be able to share cache data with each other. This cache +store is not appropriate for large application deployments. However, it can +work well for small, low traffic sites with only a couple of server processes, +as well as development and test environments. + +New Rails projects are configured to use this implementation in development environment by default. + +NOTE: Since processes will not share cache data when using `:memory_store`, +it will not be possible to manually read, write or expire the cache via the Rails console. ### ActiveSupport::Cache::FileStore @@ -243,75 +418,94 @@ This cache store uses the file system to store entries. The path to the director config.cache_store = :file_store, "/path/to/cache/directory" ``` -With this cache store, multiple server processes on the same host can share a cache. Servers processes running on different hosts could share a cache by using a shared file system, but that set up would not be ideal and is not recommended. The cache store is appropriate for low to medium traffic sites that are served off one or two hosts. +With this cache store, multiple server processes on the same host can share a +cache. This cache store is appropriate for low to medium traffic sites that are +served off one or two hosts. Server processes running on different hosts could +share a cache by using a shared file system, but that setup is not recommended. -Note that the cache will grow until the disk is full unless you periodically clear out old entries. +As the cache will grow until the disk is full, it is recommended to +periodically clear out old entries. -This is the default cache store implementation. +This is the default cache store implementation (at `"#{root}/tmp/cache/"`) if +no explicit `config.cache_store` is supplied. ### 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 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. +When initializing the cache, you need to specify the addresses for all +memcached servers in your cluster. If none are specified, it will assume +memcached is running on localhost on the default port, but this is not an ideal +setup for larger sites. -The `write` and `fetch` methods on this cache accept two additional options that take advantage of features specific to memcached. You can specify `:raw` to send a value directly to the server with no serialization. The value must be a string or number. You can use memcached direct operation like `increment` and `decrement` only on raw values. You can also specify `:unless_exist` if you don't want memcached to overwrite an existing entry. +The `write` and `fetch` methods on this cache accept two additional options that take advantage of features specific to memcached. You can specify `:raw` to send a value directly to the server with no serialization. The value must be a string or number. You can use memcached direct operations like `increment` and `decrement` only on raw values. You can also specify `:unless_exist` if you don't want memcached to overwrite an existing entry. ```ruby config.cache_store = :mem_cache_store, "cache-1.example.com", "cache-2.example.com" ``` -### ActiveSupport::Cache::EhcacheStore +### ActiveSupport::Cache::RedisCacheStore -If you are using JRuby you can use Terracotta's Ehcache as the cache store for your application. Ehcache is an open source Java cache that also offers an enterprise version with increased scalability, management, and commercial support. You must first install the jruby-ehcache-rails3 gem (version 1.1.0 or later) to use this cache store. +The Redis cache store takes advantage of Redis support for least-recently-used +and least-frequently-used key eviction when it reaches max memory, allowing it +to behave much like a Memcached cache server. -```ruby -config.cache_store = :ehcache_store -``` +Deployment note: Redis doesn't expire keys by default, so take care to use a +dedicated Redis cache server. Don't fill up your persistent-Redis server with +volatile cache data! Read the +[Redis cache server setup guide](https://redis.io/topics/lru-cache) in detail. -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). +For an all-cache Redis server, set `maxmemory-policy` to an `allkeys` policy. +Redis 4+ support least-frequently-used (`allkeys-lfu`) eviction, an excellent +default choice. Redis 3 and earlier should use `allkeys-lru` for +least-recently-used eviction. -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: +Set cache read and write timeouts relatively low. Regenerating a cached value +is often faster than waiting more than a second to retrieve it. Both read and +write timeouts default to 1 second, but may be set lower if your network is +consistently low latency. -| Property | Argument Type | Description | -| --------------------------- | ------------------- | ----------------------------------------------------------- | -| elementEvictionData | ElementEvictionData | Sets this element's eviction data instance. | -| eternal | boolean | Sets whether the element is eternal. | -| timeToIdle, tti | int | Sets time to idle | -| timeToLive, ttl, expires_in | int | Sets time to Live | -| version | long | Sets the version attribute of the ElementAttributes object. | +Cache reads and writes never raise exceptions. They just return `nil` instead, +behaving as if there was nothing in the cache. To gauge whether your cache is +hitting exceptions, you may provide an `error_handler` to report to an +exception gathering service. It must accept three keyword arguments: `method`, +the cache store method that was originally called; `returning`, the value that +was returned to the user, typically `nil`; and `exception`, the exception that +was rescued. -These options are passed to the `write` method as Hash options using either camelCase or underscore notation, as in the following examples: +Putting it all together, a production Redis cache store may look something +like this: ```ruby -Rails.cache.write('key', 'value', time_to_idle: 60.seconds, timeToLive: 600.seconds) -caches_action :index, expires_in: 60.seconds, unless_exist: true +cache_servers = %w[ "redis://cache-01:6379/0", "redis://cache-02:6379/0", … ], +config.cache_store = :redis_cache_store, url: cache_servers, + + connect_timeout: 30, # Defaults to 20 seconds + read_timeout: 0.2, # Defaults to 1 second + write_timeout: 0.2, # Defaults to 1 second + + error_handler: -> (method:, returning:, exception:) { + # Report errors to Sentry as warnings + Raven.capture_exception exception, level: 'warning", + tags: { method: method, returning: returning } + } ``` -For more information about Ehcache, see [http://ehcache.org/](http://ehcache.org/) . -For more information about Ehcache for JRuby and Rails, see [http://ehcache.org/documentation/jruby.html](http://ehcache.org/documentation/jruby.html) - ### ActiveSupport::Cache::NullStore -This cache store implementation is meant to be used only in development or test environments and it never stores anything. This can be very useful in development when you have code that interacts directly with `Rails.cache`, but caching may interfere with being able to see the results of code changes. With this cache store, all `fetch` and `read` operations will result in a miss. +This cache store implementation is meant to be used only in development or test environments and it never stores anything. This can be very useful in development when you have code that interacts directly with `Rails.cache` but caching may interfere with being able to see the results of code changes. With this cache store, all `fetch` and `read` operations will result in a miss. ```ruby config.cache_store = :null_store ``` -### Custom Cache Stores +Cache Keys +---------- -You can create your own custom cache store by simply extending `ActiveSupport::Cache::Store` and implementing the appropriate methods. In this way, you can swap in any number of caching technologies into your Rails application. - -To use a custom cache store, simple set the cache store to a new instance of the class. - -```ruby -config.cache_store = MyCacheStore.new -``` - -### Cache Keys - -The keys used in a cache can be any object that responds to either `:cache_key` or to `:to_param`. You can implement the `:cache_key` method on your classes if you need to generate custom keys. Active Record will generate keys based on the class name and record id. +The keys used in a cache can be any object that responds to either `cache_key` or +`to_param`. You can implement the `cache_key` method on your classes if you need +to generate custom keys. Active Record will generate keys based on the class name +and record id. You can use Hashes and Arrays of values as cache keys. @@ -320,7 +514,12 @@ You can use Hashes and Arrays of values as cache keys. Rails.cache.read(site: "mysite", owners: [owner_1, owner_2]) ``` -The keys you use on `Rails.cache` will not be the same as those actually used with the storage engine. They may be modified with a namespace or altered to fit technology backend constraints. This means, for instance, that you can't save values with `Rails.cache` and then try to pull them out with the `memcache-client` gem. However, you also don't need to worry about exceeding the memcached size limit or violating syntax rules. +The keys you use on `Rails.cache` will not be the same as those actually used with +the storage engine. They may be modified with a namespace or altered to fit +technology backend constraints. This means, for instance, that you can't save +values with `Rails.cache` and then try to pull them out with the `dalli` gem. +However, you also don't need to worry about exceeding the memcached size limit or +violating syntax rules. Conditional GET support ----------------------- @@ -353,7 +552,7 @@ class ProductsController < ApplicationController end ``` -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`: +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 @@ -383,3 +582,81 @@ class ProductsController < ApplicationController end end ``` + +Sometimes we want to cache response, for example a static page, that never gets +expired. To achieve this, we can use `http_cache_forever` helper and by doing +so browser and proxies will cache it indefinitely. + +By default cached responses will be private, cached only on the user's web +browser. To allow proxies to cache the response, set `public: true` to indicate +that they can serve the cached response to all users. + +Using this helper, `last_modified` header is set to `Time.new(2011, 1, 1).utc` +and `expires` header is set to a 100 years. + +WARNING: Use this method carefully as browser/proxy won't be able to invalidate +the cached response unless browser cache is forcefully cleared. + +```ruby +class HomeController < ApplicationController + def index + http_cache_forever(public: true) do + render + end + end +end +``` + +### Strong v/s Weak ETags + +Rails generates weak ETags by default. Weak ETags allow semantically equivalent +responses to have the same ETags, even if their bodies do not match exactly. +This is useful when we don't want the page to be regenerated for minor changes in +response body. + +Weak ETags have a leading `W/` to differentiate them from strong ETags. + +``` + W/"618bbc92e2d35ea1945008b42799b0e7" → Weak ETag + "618bbc92e2d35ea1945008b42799b0e7" → Strong ETag +``` + +Unlike weak ETag, strong ETag implies that response should be exactly the same +and byte by byte identical. Useful when doing Range requests within a +large video or PDF file. Some CDNs support only strong ETags, like Akamai. +If you absolutely need to generate a strong ETag, it can be done as follows. + +```ruby + class ProductsController < ApplicationController + def show + @product = Product.find(params[:id]) + fresh_when last_modified: @product.published_at.utc, strong_etag: @product + end + end +``` + +You can also set the strong ETag directly on the response. + +```ruby + response.strong_etag = response.body # => "618bbc92e2d35ea1945008b42799b0e7" +``` + +Caching in Development +---------------------- + +It's common to want to test the caching strategy of your application +in development mode. Rails provides the rake task `dev:cache` to +easily toggle caching on/off. + +```bash +$ bin/rails dev:cache +Development mode is now being cached. +$ bin/rails dev:cache +Development mode is no longer being cached. +``` + +References +---------- + +* [DHH's article on key-based expiration](https://signalvnoise.com/posts/3113-how-key-based-cache-expiration-works) +* [Ryan Bates' Railscast on cache digests](http://railscasts.com/episodes/387-cache-digests) diff --git a/guides/source/command_line.md b/guides/source/command_line.md index b409f20122..648645af7c 100644 --- a/guides/source/command_line.md +++ b/guides/source/command_line.md @@ -21,7 +21,7 @@ There are a few commands that are absolutely critical to your everyday usage of * `rails console` * `rails server` -* `rake` +* `bin/rails` * `rails generate` * `rails dbconsole` * `rails new app_name` @@ -39,7 +39,7 @@ INFO: You can install the rails gem by typing `gem install rails`, if you don't ```bash $ rails new commandsapp create - create README.rdoc + create README.md create Rakefile create config.ru create .gitignore @@ -55,20 +55,22 @@ Rails will set you up with what seems like a huge amount of stuff for such a tin ### `rails server` -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. +The `rails server` command launches a web server named Puma which comes bundled with Rails. You'll use this any time you want to access your application through a web browser. With no further work, `rails server` will run our new shiny Rails app: ```bash $ cd commandsapp $ bin/rails server -=> Booting WEBrick -=> Rails 5.0.0 application starting in development on http://localhost:3000 -=> Call with -d to detach -=> Ctrl-C to shutdown server -[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 +=> Booting Puma +=> Rails 5.1.0 application starting in development on http://0.0.0.0:3000 +=> Run `rails server -h` for more startup options +Puma starting in single mode... +* Version 3.0.2 (ruby 2.3.0-p0), codename: Plethora of Penguin Pinatas +* Min threads: 5, max threads: 5 +* Environment: development +* Listening on tcp://localhost:3000 +Use Ctrl-C to stop ``` 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. @@ -100,6 +102,7 @@ Please choose a generator below. Rails: assets + channel controller generator ... @@ -181,7 +184,7 @@ Fire up your server using `rails server`. ```bash $ bin/rails server -=> Booting WEBrick... +=> Booting Puma... ``` The URL will be [http://localhost:3000/greetings/hello](http://localhost:3000/greetings/hello). @@ -207,7 +210,7 @@ Description: Create rails files for model generator. ``` -NOTE: For a list of available field types, refer to the [API documentation](http://api.rubyonrails.org/classes/ActiveRecord/ConnectionAdapters/TableDefinition.html#method-i-column) for the column method for the `TableDefinition` class. +NOTE: For a list of available field types for the `type` parameter, refer to the [API documentation](http://api.rubyonrails.org/classes/ActiveRecord/ConnectionAdapters/SchemaStatements.html#method-i-add_column) for the add_column method for the `SchemaStatements` module. The `index` parameter generates a corresponding index for the column. But instead of generating a model directly (which we'll be doing later), let's set up a scaffold. A **scaffold** in Rails is a full set of model, database migration for that model, controller to manipulate it, views to view and manipulate the data, and a test suite for each of the above. @@ -239,6 +242,8 @@ $ bin/rails generate scaffold HighScore game:string score:integer invoke jbuilder create app/views/high_scores/index.json.jbuilder create app/views/high_scores/show.json.jbuilder + invoke test_unit + create test/system/high_scores_test.rb invoke assets invoke coffee create app/assets/javascripts/high_scores.coffee @@ -250,17 +255,23 @@ $ bin/rails generate scaffold HighScore game:string score:integer 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 `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. +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 `bin/rails db:migrate` command. We'll talk more about bin/rails in-depth in a little while. ```bash -$ bin/rake db:migrate +$ bin/rails db:migrate == CreateHighScores: migrating =============================================== -- create_table(:high_scores) -> 0.0017s == CreateHighScores: migrated (0.0019s) ====================================== ``` -INFO: Let's talk about unit tests. Unit tests are code that tests and makes assertions about code. In unit testing, we take a little part of code, say a method of a model, and test its inputs and outputs. Unit tests are your friend. The sooner you make peace with the fact that your quality of life will drastically increase when you unit test your code, the better. Seriously. We'll make one in a moment. +INFO: Let's talk about unit tests. Unit tests are code that tests and makes assertions +about code. In unit testing, we take a little part of code, say a method of a model, +and test its inputs and outputs. Unit tests are your friend. The sooner you make +peace with the fact that your quality of life will drastically increase when you unit +test your code, the better. Seriously. Please visit +[the testing guide](http://guides.rubyonrails.org/testing.html) for an in-depth +look at unit testing. Let's see the interface Rails created for us. @@ -279,14 +290,14 @@ 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 -$ bin/rails console staging +$ bin/rails console -e staging ``` If you wish to test out some code without changing any data, you can do that by invoking `rails console --sandbox`. ```bash $ bin/rails console --sandbox -Loading development environment in sandbox (Rails 5.0.0) +Loading development environment in sandbox (Rails 5.1.0) Any modifications you make will be rolled back on exit irb(main):001:0> ``` @@ -318,7 +329,7 @@ With the `helper` method it is possible to access Rails and your application's h ### `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. +`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 (including MariaDB), PostgreSQL and SQLite3. INFO: You can also use the alias "db" to invoke the dbconsole: `rails db`. @@ -369,44 +380,63 @@ $ bin/rails destroy model Oops remove test/fixtures/oops.yml ``` -Rake ----- +bin/rails +--------- -Rake is Ruby Make, a standalone Ruby utility that replaces the Unix utility 'make', and uses a 'Rakefile' and `.rake` files to build up a list of tasks. In Rails, Rake is used for common administration tasks, especially sophisticated ones that build off of each other. +Since Rails 5.0+ has rake commands built into the rails executable, `bin/rails` is the new default for running commands. -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`. +You can get a list of bin/rails tasks available to you, which will often depend on your current directory, by typing `bin/rails --help`. Each task has a description, and should help you find the thing you need. ```bash -$ bin/rake --tasks -rake about # List versions of all Rails frameworks and the environment -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 +$ bin/rails --help +Usage: rails COMMAND [ARGS] + +The most common rails commands are: +generate Generate new code (short-cut alias: "g") +console Start the Rails console (short-cut alias: "c") +server Start the Rails server (short-cut alias: "s") +... + +All commands can be run with -h (or --help) for more information. + +In addition to those commands, there are: +about List versions of all Rails ... +assets:clean[keep] Remove old compiled assets +assets:clobber Remove compiled assets +assets:environment Load asset compile environment +assets:precompile Compile all the assets ... ... -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 +db:fixtures:load Loads fixtures into the ... +db:migrate Migrate the database ... +db:migrate:status Display status of migrations +db:rollback Rolls the schema back to ... +db:schema:cache:clear Clears a db/schema_cache.yml file +db:schema:cache:dump Creates a db/schema_cache.yml file +db:schema:dump Creates a db/schema.rb file ... +db:schema:load Loads a schema.rb file ... +db:seed Loads the seed data ... +db:structure:dump Dumps the database structure ... +db:structure:load Recreates the databases ... +db:version Retrieves the current schema ... ... -rake tmp:clear # Clear cache and socket files from tmp/ (narrow w/ tmp:cache:clear, tmp:sockets:clear) -rake tmp:create # Creates tmp directories for cache, sockets, and pids +restart Restart app by touching ... +tmp:create Creates tmp directories ... ``` -INFO: You can also use `rake -T` to get the list of tasks. +INFO: You can also use `bin/rails -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. +`bin/rails 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 -$ bin/rake about +$ bin/rails about About your application's environment -Rails version 5.0.0 -Ruby version 2.2.1 (x86_64-linux) -RubyGems version 2.4.5 -Rack version 1.6 +Rails version 5.1.0 +Ruby version 2.2.2 (x86_64-linux) +RubyGems version 2.4.6 +Rack version 2.0.1 JavaScript Runtime Node.js (V8) -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 +Middleware: Rack::Sendfile, ActionDispatch::Static, ActionDispatch::Executor, ActiveSupport::Cache::Strategy::LocalCache::Middleware, Rack::Runtime, Rack::MethodOverride, ActionDispatch::RequestId, ActionDispatch::RemoteIp, Sprockets::Rails::QuietAssets, Rails::Rack::Logger, ActionDispatch::ShowExceptions, WebConsole::Middleware, ActionDispatch::DebugExceptions, ActionDispatch::Reloader, ActionDispatch::Callbacks, ActiveRecord::Migration::CheckPending, ActionDispatch::Cookies, ActionDispatch::Session::CookieStore, ActionDispatch::Flash, Rack::Head, Rack::ConditionalGet, Rack::ETag Application root /home/foobar/commandsapp Environment development Database adapter sqlite3 @@ -415,22 +445,22 @@ Database schema version 20110805173523 ### `assets` -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. +You can precompile the assets in `app/assets` using `bin/rails assets:precompile`, and remove older compiled assets using `bin/rails 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`. +If you want to clear `public/assets` completely, you can use `bin/rails assets:clobber`. ### `db` -The most common tasks of the `db:` Rake namespace are `migrate` and `create`, and it will pay off to try out all of the migration rake tasks (`up`, `down`, `redo`, `reset`). `rake db:version` is useful when troubleshooting, telling you the current version of the database. +The most common tasks of the `db:` bin/rails namespace are `migrate` and `create`, and it will pay off to try out all of the migration bin/rails tasks (`up`, `down`, `redo`, `reset`). `bin/rails db:version` is useful when troubleshooting, telling you the current version of the database. -More information about migrations can be found in the [Migrations](migrations.html) guide. +More information about migrations can be found in the [Migrations](active_record_migrations.html) guide. ### `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`, `.rake`, `.yml`, `.yaml`, `.ruby`, `.css`, `.js` and `.erb` for both default and custom annotations. +`bin/rails 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 -$ bin/rake notes +$ bin/rails notes (in /home/foobar/commandsapp) app/controllers/admin/users_controller.rb: * [ 20] [TODO] any other way to do this? @@ -447,10 +477,10 @@ You can add support for new file extensions using `config.annotations.register_e config.annotations.register_extensions("scss", "sass", "less") { |annotation| /\/\/\s*(#{annotation}):?\s*(.*)$/ } ``` -If you are looking for a specific annotation, say FIXME, you can use `rake notes:fixme`. Note that you have to lower case the annotation's name. +If you are looking for a specific annotation, say FIXME, you can use `bin/rails notes:fixme`. Note that you have to lower case the annotation's name. ```bash -$ bin/rake notes:fixme +$ bin/rails notes:fixme (in /home/foobar/commandsapp) app/controllers/admin/users_controller.rb: * [132] high priority for next deploy @@ -459,10 +489,10 @@ 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`. +You can also use custom annotations in your code and list them using `bin/rails notes:custom` by specifying the annotation using an environment variable `ANNOTATION`. ```bash -$ bin/rake notes:custom ANNOTATION=BUG +$ bin/rails notes:custom ANNOTATION=BUG (in /home/foobar/commandsapp) app/models/article.rb: * [ 23] Have to fix this one before pushing! @@ -470,11 +500,17 @@ app/models/article.rb: 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`, `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`. +By default, `rails notes` will look in the `app`, `config`, `db`, `lib` and `test` directories. If you would like to search other directories, you can configure them using `config.annotations.register_directories` option. + +```ruby +config.annotations.register_directories("spec", "vendor") +``` + +You can also provide them as a comma separated list in the environment variable `SOURCE_ANNOTATION_DIRECTORIES`. ```bash $ export SOURCE_ANNOTATION_DIRECTORIES='spec,vendor' -$ bin/rake notes +$ bin/rails notes (in /home/foobar/commandsapp) app/models/user.rb: * [ 35] [FIXME] User should have a subscription at this point @@ -484,7 +520,7 @@ spec/models/user_spec.rb: ### `routes` -`rake routes` will list all of your defined routes, which is useful for tracking down routing problems in your app, or giving you a good overview of the URLs in an app you're trying to get familiar with. +`rails routes` will list all of your defined routes, which is useful for tracking down routing problems in your app, or giving you a good overview of the URLs in an app you're trying to get familiar with. ### `test` @@ -498,16 +534,17 @@ The `Rails.root/tmp` directory is, like the *nix /tmp directory, the holding pla The `tmp:` namespaced tasks will help you clear and create the `Rails.root/tmp` directory: -* `rake tmp:cache:clear` clears `tmp/cache`. -* `rake tmp:sockets:clear` clears `tmp/sockets`. -* `rake tmp:clear` clears all cache and sockets files. -* `rake tmp:create` creates tmp directories for cache, sockets and pids. +* `rails tmp:cache:clear` clears `tmp/cache`. +* `rails tmp:sockets:clear` clears `tmp/sockets`. +* `rails tmp:screenshots:clear` clears `tmp/screenshots`. +* `rails tmp:clear` clears all cache, sockets and screenshot files. +* `rails tmp:create` creates tmp directories for cache, sockets and pids. ### Miscellaneous -* `rake stats` is great for looking at statistics on your code, displaying things like KLOCs (thousands of lines of code) and your code to test ratio. -* `rake secret` will give you a pseudo-random key to use for your session secret. -* `rake time:zones:all` lists all the timezones Rails knows about. +* `rails stats` is great for looking at statistics on your code, displaying things like KLOCs (thousands of lines of code) and your code to test ratio. +* `rails secret` will give you a pseudo-random key to use for your session secret. +* `rails time:zones:all` lists all the timezones Rails knows about. ### Custom Rake Tasks @@ -545,9 +582,9 @@ end Invocation of the tasks will look like: ```bash -$ bin/rake task_name -$ bin/rake "task_name[value 1]" # entire argument string should be quoted -$ bin/rake db:nothing +$ bin/rails task_name +$ bin/rails "task_name[value 1]" # entire argument string should be quoted +$ bin/rails 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. @@ -578,8 +615,8 @@ $ rails new . --git --database=postgresql create tmp/pids create Rakefile add 'Rakefile' - create README.rdoc -add 'README.rdoc' + create README.md +add 'README.md' create app/controllers/application_controller.rb add 'app/controllers/application_controller.rb' create app/helpers/application_helper.rb @@ -592,7 +629,7 @@ We had to create the **gitapp** directory and initialize an empty git repository ```bash $ cat config/database.yml -# PostgreSQL. Versions 8.2 and up are supported. +# PostgreSQL. Versions 9.1 and up are supported. # # Install the pg driver: # gem install pg @@ -608,17 +645,20 @@ $ cat config/database.yml # Configure Using Gemfile # gem 'pg' # -development: +default: &default adapter: postgresql encoding: unicode + # For details on connection pooling, see Rails configuration guide + # http://guides.rubyonrails.org/configuring.html#database-pooling + pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %> + +development: + <<: *default database: gitapp_development - pool: 5 - username: gitapp - password: ... ... ``` -It also generated some lines in our database.yml configuration corresponding to our choice of PostgreSQL for database. +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. diff --git a/guides/source/configuring.md b/guides/source/configuring.md index 67285030a9..1668f9e81a 100644 --- a/guides/source/configuring.md +++ b/guides/source/configuring.md @@ -32,10 +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 `config/application.rb` file includes this setting: +For example, you could add this setting to `config/application.rb` file: ```ruby -config.autoload_paths += %W(#{config.root}/extras) +config.time_zone = 'Central Time (US & Canada)' ``` 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`: @@ -60,22 +60,20 @@ These configuration methods are to be called on a `Rails::Railtie` object, such * `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_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. - -* `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.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.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.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`. -* `config.colorize_logging` specifies whether or not to use ANSI color codes when logging information. Defaults to true. +* `config.colorize_logging` specifies whether or not to use ANSI color codes when logging information. Defaults to `true`. -* `config.consider_all_requests_local` is a flag. If true then any error will cause detailed debugging information to be dumped in the HTTP response, and the `Rails::Info` controller will show the application runtime context in `/rails/info/properties`. True by default in development and test environments, and false in production mode. For finer-grained control, set this to false and implement `local_request?` in controllers to specify which requests should provide debugging information on errors. +* `config.consider_all_requests_local` is a flag. If `true` then any error will cause detailed debugging information to be dumped in the HTTP response, and the `Rails::Info` controller will show the application runtime context in `/rails/info/properties`. `true` by default in development and test environments, and `false` in production mode. For finer-grained control, set this to `false` and implement `local_request?` in controllers to specify which requests should provide debugging information on errors. * `config.console` allows you to set class that will be used as console you run `rails console`. It's best to run it in `console` block: @@ -88,45 +86,61 @@ application. Accepts a valid week day symbol (e.g. `:monday`). 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. - -* `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. +* `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. -* `config.eager_load_namespaces` registers namespaces that are eager loaded when `config.eager_load` is true. All namespaces in the list must respond to the `eager_load!` method. +* `config.eager_load_namespaces` registers namespaces that are eager loaded when `config.eager_load` is `true`. All namespaces in the list must respond to the `eager_load!` method. * `config.eager_load_paths` accepts an array of paths from which Rails will eager load on boot if cache classes is enabled. Defaults to every folder in the `app` directory of the application. +* `config.enable_dependency_loading`: when true, enables autoloading, even if the application is eager loaded and `config.cache_classes` is set as true. Defaults to false. + * `config.encoding` sets up the application-wide encoding. Defaults to UTF-8. * `config.exceptions_app` sets the exceptions application invoked by the ShowException middleware when an exception happens. Defaults to `ActionDispatch::PublicExceptions.new(Rails.public_path)`. -* `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.debug_exception_response_format` sets the format used in responses when errors occur in development mode. Defaults to `:api` for API only apps and `:default` for normal apps. + +* `config.file_watcher` is the class used to detect file updates in the file system when `config.reload_classes_only_on_change` is `true`. Rails ships with `ActiveSupport::FileUpdateChecker`, the default, and `ActiveSupport::EventedFileUpdateChecker` (this one depends on the [listen](https://github.com/guard/listen) gem). Custom classes must conform to the `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. New applications filter out passwords by adding the following `config.filter_parameters+=[:password]` in `config/initializers/filter_parameter_logging.rb`. +numbers. By default, Rails filters out passwords by adding `Rails.application.config.filter_parameters += [:password]` in `config/initializers/filter_parameter_logging.rb`. Parameters filter works by partial matching regular expression. -* `config.force_ssl` forces all requests to be under HTTPS protocol by using `ActionDispatch::SSL` middleware. +* `config.force_ssl` forces all requests to be served over HTTPS by using the `ActionDispatch::SSL` middleware, and sets `config.action_mailer.default_url_options` to be `{ protocol: 'https' }`. This can be configured by setting `config.ssl_options` - see the [ActionDispatch::SSL documentation](http://api.rubyonrails.org/classes/ActionDispatch/SSL.html) for details. -* `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_formatter` defines the formatter of the Rails logger. This option defaults to an instance of `ActiveSupport::Logger::SimpleFormatter` for all modes. If you are setting a value for `config.logger` you must manually pass the value of your formatter to your logger before it is wrapped in an `ActiveSupport::TaggedLogging` instance, Rails will not do it for you. * `config.log_level` defines the verbosity of the Rails logger. This option defaults to `:debug` for all environments. The available log levels are: `:debug`, `:info`, `:warn`, `:error`, `:fatal`, and `:unknown`. -* `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.log_tags` accepts a list of: methods that the `request` object responds to, a `Proc` that accepts the `request` object, or something that responds to `to_s`. 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`. +* `config.logger` is the logger that will be used for `Rails.logger` and any related Rails logging such as `ActiveRecord::Base.logger`. It defaults to an instance of `ActiveSupport::TaggedLogging` that wraps an instance of `ActiveSupport::Logger` which outputs a log to the `log/` directory. You can supply a custom logger, to get full compatibility you must follow these guidelines: + * To support a formatter, you must manually assign a formatter from the `config.log_formatter` value to the logger. + * To support tagged logs, the log instance must be wrapped with `ActiveSupport::TaggedLogging`. + * To support silencing, the logger must include `LoggerSilence` and `ActiveSupport::LoggerThreadSafeLevel` modules. The `ActiveSupport::Logger` class already includes these modules. + + ```ruby + class MyLogger < ::Logger + include ActiveSupport::LoggerThreadSafeLevel + include LoggerSilence + end + + mylogger = MyLogger.new(STDOUT) + mylogger.formatter = config.log_formatter + config.logger = ActiveSupport::TaggedLogging.new(mylogger) + ``` * `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.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. -* `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`. +* `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 a random generated key in test and development environments, other environments should set one in `config/credentials.yml.enc`. -* `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.public_file_server.enabled` configures Rails to serve static files from the public directory. 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: +* `config.session_store` 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. Defaults to a cookie store with application name as the session key. Custom session stores can also be specified: ```ruby config.session_store :my_custom_store @@ -139,35 +153,35 @@ defaults to `:debug` for all environments. The available log levels are: `:debug ### Configuring Assets * `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/environments/production.rb`. +pipeline is enabled. It is set to `true` by default. * `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. * `config.assets.js_compressor` defines the JavaScript compressor to use. Possible values are `:closure`, `:uglifier` and `:yui` which require the use of the `closure-compiler`, `uglifier` or `yui-compressor` gems respectively. +* `config.assets.gzip` a flag that enables the creation of gzipped version of compiled assets, along with non-gzipped assets. Set to `true` by default. + * `config.assets.paths` contains the paths which are used to look for assets. Appending paths to this configuration option will cause those paths to be used in the search for assets. * `config.assets.precompile` allows you to specify additional assets (other than `application.css` and `application.js`) which are to be precompiled when `rake assets:precompile` is run. +* `config.assets.unknown_asset_fallback` allows you to modify the behavior of the asset pipeline when an asset is not in the pipeline, if you use sprockets-rails 3.2.0 or newer. Defaults to `true`. + * `config.assets.prefix` defines the prefix where assets are served from. Defaults to `/assets`. * `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.digest` enables the use of SHA256 fingerprints in asset names. Set to `true` by default. * `config.assets.debug` disables the concatenation and compression of assets. Set to `true` by default in `development.rb`. -* `config.assets.cache_store` defines the cache store that Sprockets will use. The default is the Rails file store. - -* `config.assets.version` is an option string that is used in MD5 hash generation. This can be changed to force all files to be recompiled. +* `config.assets.version` is an option string that is used in SHA256 hash generation. This can be changed to force all files to be recompiled. * `config.assets.compile` is a boolean that can be used to turn on live Sprockets compilation in production. -* `config.assets.logger` accepts a logger conforming to the interface of Log4r or the default Ruby `Logger` class. Defaults to the same configured at `config.logger`. Setting `config.assets.logger` to false will turn off served assets logging. +* `config.assets.logger` accepts a logger conforming to the interface of Log4r or the default Ruby `Logger` class. Defaults to the same configured at `config.logger`. Setting `config.assets.logger` to `false` will turn off served assets logging. + +* `config.assets.quiet` disables logging of assets requests. Set to `true` by default in `development.rb`. ### Configuring Generators @@ -185,24 +199,27 @@ The full set of methods that can be used in this block are as follows: * `assets` allows to create assets on generating a scaffold. Defaults to `true`. * `force_plural` allows pluralized model names. Defaults to `false`. * `helper` defines whether or not to generate helpers. Defaults to `true`. -* `integration_tool` defines which integration tool to use. Defaults to `nil`. +* `integration_tool` defines which integration tool to use to generate integration tests. Defaults to `:test_unit`. * `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`. +* `javascript_engine` configures the engine to be used (for eg. coffee) when generating assets. Defaults to `:js`. * `orm` defines which orm to use. Defaults to `false` and will use Active Record by default. * `resource_controller` defines which generator to use for generating a controller when using `rails generate resource`. Defaults to `:controller`. +* `resource_route` defines whether a resource route definition should be generated + or not. Defaults to `true`. * `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`. * `stylesheet_engine` configures the stylesheet engine (for eg. sass) to be used when generating assets. Defaults to `:css`. -* `test_framework` defines which test framework to use. Defaults to `false` and will use Test::Unit by default. +* `scaffold_stylesheet` creates `scaffold.css` when generating a scaffolded resource. Defaults to `true`. +* `test_framework` defines which test framework to use. Defaults to `false` and will use Minitest by default. * `template_engine` defines which template engine to use, such as ERB or Haml. Defaults to `:erb`. ### Configuring Middleware 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_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`. +* `ActionDispatch::SSL` forces every request to be served using HTTPS. Enabled if `config.force_ssl` is set to `true`. Options passed to this can be configured by setting `config.ssl_options`. +* `ActionDispatch::Static` is used to serve static assets. Disabled if `config.public_file_server.enabled` is `false`. Set `config.public_file_server.index_name` if you need to serve a static directory index file that is not named `index`. For example, to serve `main.html` instead of `index.html` for directory requests, set `config.public_file_server.index_name` to `"main"`. +* `ActionDispatch::Executor` allows thread safe code reloading. Disabled if `config.allow_concurrency` is `false`, which causes `Rack::Lock` to be loaded. `Rack::Lock` wraps the app in mutex so it can only be called by a single thread at a time. * `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 begun. After request is complete, flushes all the logs. @@ -211,12 +228,9 @@ Every Rails application comes with a standard set of middleware which it uses in * `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`. -* `ActiveRecord::QueryCache` caches all SELECT queries generated in a request. If any INSERT or UPDATE takes place then the cache is cleaned. * `ActionDispatch::Cookies` sets cookies for the request. * `ActionDispatch::Session::CookieStore` is responsible for storing the session in cookies. An alternate middleware can be used for this by changing the `config.action_controller.session_store` to an alternate value. Additionally, options passed to this can be configured by using `config.action_controller.session_options`. * `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. * `Rack::Head` converts HEAD requests to GET requests and serves them as so. @@ -232,6 +246,12 @@ This will put the `Magical::Unicorns` middleware on the end of the stack. You ca config.middleware.insert_before Rack::Head, Magical::Unicorns ``` +Or you can insert a middleware to exact position by using indexes. For example, if you want to insert `Magical::Unicorns` middleware on top of the stack, you can do it, like so: + +```ruby +config.middleware.insert_before 0, Magical::Unicorns +``` + There's also `insert_after` which will insert a middleware after another: ```ruby @@ -247,7 +267,7 @@ config.middleware.swap ActionController::Failsafe, Lifo::Failsafe They can also be removed from the stack completely: ```ruby -config.middleware.delete "Rack::MethodOverride" +config.middleware.delete Rack::MethodOverride ``` ### Configuring i18n @@ -262,6 +282,28 @@ All these configuration options are delegated to the `I18n` library. * `config.i18n.load_path` sets the path Rails uses to look for locale files. Defaults to `config/locales/*.{yml,rb}`. +* `config.i18n.fallbacks` sets fallback behavior for missing translations. Here are 3 usage examples for this option: + + * You can set the option to `true` for using default locale as fallback, like so: + + ```ruby + config.i18n.fallbacks = true + ``` + + * Or you can set an array of locales as fallback, like so: + + ```ruby + config.i18n.fallbacks = [:tr, :en] + ``` + + * Or you can set different fallbacks for locales individually. For example, if you want to use `:tr` for `:az` and `:de`, `:en` for `:da` as fallbacks, you can do it, like so: + + ```ruby + config.i18n.fallbacks = { az: :tr, da: [:de, :en] } + #or + config.i18n.fallbacks.map = { az: :tr, da: [:de, :en] } + ``` + ### Configuring Active Record `config.active_record` includes a variety of configuration options: @@ -269,8 +311,8 @@ All these configuration options are delegated to the `I18n` library. * `config.active_record.logger` accepts a logger conforming to the interface of Log4r or the default Ruby Logger class, which is then passed on to any new database connections made. You can retrieve this logger by calling `logger` on either an Active Record model class or an Active Record model instance. Set to `nil` to disable logging. * `config.active_record.primary_key_prefix_type` lets you adjust the naming for primary key columns. By default, Rails assumes that primary key columns are named `id` (and this configuration option doesn't need to be set.) There are two other choices: -** `:table_name` would make the primary key for the Customer class `customerid` -** `:table_name_with_underscore` would make the primary key for the Customer class `customer_id` + * `:table_name` would make the primary key for the Customer class `customerid`. + * `:table_name_with_underscore` would make the primary key for the Customer class `customer_id`. * `config.active_record.table_name_prefix` lets you set a global string to be prepended to table names. If you set this to `northwest_`, then the Customer class will look for `northwest_customers` as its table. The default is an empty string. @@ -278,15 +320,21 @@ All these configuration options are delegated to the `I18n` library. * `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.internal_metadata_table_name` lets you set a string to be used as the name of the internal metadata table. + +* `config.active_record.protected_environments` lets you set an array of names of environments where destructive actions should be prohibited. + +* `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`. * `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. -* `config.active_record.timestamped_migrations` controls whether migrations are numbered with serial integers or with timestamps. The default is true, to use timestamps, which are preferred if there are multiple developers working on the same application. +* `config.active_record.error_on_ignored_order` specifies if an error should be raised if the order of a query is ignored during a batch query. The options are `true` (raise error) or `false` (warn). Default is `false`. + +* `config.active_record.timestamped_migrations` controls whether migrations are numbered with serial integers or with timestamps. The default is `true`, to use timestamps, which are preferred if there are multiple developers working on the same application. -* `config.active_record.lock_optimistically` controls whether Active Record will use optimistic locking and is true by default. +* `config.active_record.lock_optimistically` controls whether Active Record will use optimistic locking and is `true` by default. * `config.active_record.cache_timestamp_format` controls the format of the timestamp value in the cache key. Default is `:nsec`. @@ -294,28 +342,66 @@ All these configuration options are delegated to the `I18n` library. * `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.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 + `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. + default value is `true` if this configuration is not set. -* `config.active_record.dump_schemas` controls which database schemas will be dumped when calling db:structure:dump. - The options are `:schema_search_path` (the default) which dumps any schemas listed in schema_search_path, - `:all` which always dumps all schemas regardless of the schema_search_path, +* `config.active_record.dump_schemas` controls which database schemas will be dumped when calling `db:structure:dump`. + The options are `:schema_search_path` (the default) which dumps any schemas listed in `schema_search_path`, + `:all` which always dumps all schemas regardless of the `schema_search_path`, or a string of comma separated schemas. -* `config.active_record.belongs_to_required_by_default` is a boolean value and controls whether `belongs_to` association is required by default. +* `config.active_record.belongs_to_required_by_default` is a boolean value and + controls whether a record fails validation if `belongs_to` association is not + present. + +* `config.active_record.warn_on_records_fetched_greater_than` allows setting a + warning threshold for query result size. If the number of records returned + by a query exceeds the threshold, a warning is logged. This can be used to + identify queries which might be causing a memory bloat. + +* `config.active_record.index_nested_attribute_errors` allows errors for nested + `has_many` relationships to be displayed with an index as well as the error. + Defaults to `false`. + +* `config.active_record.use_schema_cache_dump` enables users to get schema cache information + from `db/schema_cache.yml` (generated by `bin/rails db:schema:cache:dump`), instead of + having to send a query to the database to get this information. + Defaults to `true`. The MySQL adapter adds one additional configuration option: -* `ActiveRecord::ConnectionAdapters::MysqlAdapter.emulate_booleans` controls whether Active Record will consider all `tinyint(1)` columns in a MySQL database to be booleans and is true by default. +* `ActiveRecord::ConnectionAdapters::Mysql2Adapter.emulate_booleans` controls whether Active Record will consider all `tinyint(1)` columns as booleans. Defaults to `true`. + +The SQLite3Adapter adapter adds one additional configuration option: + +* `ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer` +indicates whether boolean values are stored in sqlite3 databases as 1 and 0 or +'t' and 'f'. Leaving `ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer` +set to false is deprecated. SQLite databases have used 't' and 'f' to serialize +boolean values and must have old data converted to 1 and 0 (its native boolean +serialization) before setting this flag to true. Conversion can be accomplished +by setting up a Rake task which runs + + ```ruby + ExampleModel.where("boolean_column = 't'").update_all(boolean_column: 1) + ExampleModel.where("boolean_column = 'f'").update_all(boolean_column: 0) + ``` + + for all models and all boolean columns, after which the flag must be set to true +by adding the following to your `application.rb` file: + + ```ruby + Rails.application.config.active_record.sqlite3.represent_boolean_as_integer = true + ``` The schema dumper adds one additional configuration option: -* `ActiveRecord::SchemaDumper.ignore_tables` accepts an array of tables that should _not_ be included in any generated schema file. This setting is ignored unless `config.active_record.schema_format == :ruby`. +* `ActiveRecord::SchemaDumper.ignore_tables` accepts an array of tables that should _not_ be included in any generated schema file. ### Configuring Action Controller @@ -323,13 +409,11 @@ The schema dumper adds one additional configuration option: * `config.action_controller.asset_host` sets the host for the assets. Useful when CDNs are used for hosting assets rather than the application server itself. -* `config.action_controller.perform_caching` configures whether the application should perform caching or not. Set to false in development mode, true in production. +* `config.action_controller.perform_caching` configures whether the application should perform the caching features provided by the Action Controller component or not. Set to `false` in development mode, `true` in production. * `config.action_controller.default_static_extension` configures the extension used for cached pages. Defaults to `.html`. -* `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.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 configuration behavior (when this option is not explicitly set to `true` or `false`) is that all view helpers are available to each controller. * `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. @@ -337,6 +421,12 @@ The schema dumper adds one additional configuration option: * `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.forgery_protection_origin_check` configures whether the HTTP `Origin` header should be checked against the site's origin as an additional CSRF defense. + +* `config.action_controller.per_form_csrf_tokens` configures whether CSRF tokens are only valid for the method/action they were generated for. + +* `config.action_controller.default_protect_from_forgery` determines whether forgery protection is added on `ActionController:Base`. This is false by default, but enabled when loading defaults for Rails 5.2. + * `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`. @@ -345,6 +435,22 @@ The schema dumper adds one additional configuration option: * `config.action_controller.always_permitted_parameters` sets a list of whitelisted parameters that are permitted by default. The default values are `['controller', 'action']`. +* `config.action_controller.enable_fragment_cache_logging` determines whether to log fragment cache reads and writes in verbose format as follows: + + ``` + Read fragment views/v1/2914079/v1/2914079/recordings/70182313-20160225015037000000/d0bdf2974e1ef6d31685c3b392ad0b74 (0.6ms) + Rendered messages/_message.html.erb in 1.2 ms [cache hit] + Write fragment views/v1/2914079/v1/2914079/recordings/70182313-20160225015037000000/3b4e249ac9d168c617e32e84b99218b5 (1.1ms) + Rendered recordings/threads/_thread.html.erb in 1.5 ms [cache miss] + ``` + + By default it is set to `false` which results in following output: + + ``` + Rendered messages/_message.html.erb in 1.2 ms [cache hit] + Rendered recordings/threads/_thread.html.erb in 1.5 ms [cache miss] + ``` + ### 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. @@ -359,8 +465,14 @@ The schema dumper adds one additional configuration option: } ``` +* `config.action_dispatch.default_charset` specifies the default character set for all renders. Defaults to `nil`. + * `config.action_dispatch.tld_length` sets the TLD (top-level domain) length for the application. Defaults to `1`. +* `config.action_dispatch.ignore_accept_header` is used to determine whether to ignore accept headers from a request. Defaults to `false`. + +* `config.action_dispatch.x_sendfile_header` specifies server specific X-Sendfile header. This is useful for accelerated file sending from server. For example it can be set to 'X-Sendfile' for Apache. + * `config.action_dispatch.http_auth_salt` sets the HTTP Auth salt value. Defaults to `'http authentication'`. @@ -368,34 +480,49 @@ to `'http authentication'`. Defaults to `'signed cookie'`. * `config.action_dispatch.encrypted_cookie_salt` sets the encrypted cookies salt -value. Defaults to `'encrypted cookie'`. + value. Defaults to `'encrypted cookie'`. * `config.action_dispatch.encrypted_signed_cookie_salt` sets the signed -encrypted cookies salt value. Defaults to `'signed encrypted cookie'`. + encrypted cookies salt value. Defaults to `'signed encrypted cookie'`. + +* `config.action_dispatch.authenticated_encrypted_cookie_salt` sets the + authenticated encrypted cookie salt. Defaults to `'authenticated encrypted + cookie'`. + +* `config.action_dispatch.encrypted_cookie_cipher` sets the cipher to be + used for encrypted cookies. This defaults to `"aes-256-gcm"`. + +* `config.action_dispatch.signed_cookie_digest` sets the digest to be + used for signed cookies. This defaults to `"SHA1"`. + +* `config.action_dispatch.cookies_rotations` allows rotating + secrets, ciphers, and digests for encrypted and signed cookies. * `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. + 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 + '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::Http::Parameters::ParseError' => :bad_request, + 'ActionController::BadRequest' => :bad_request, + 'ActionController::ParameterMissing' => :bad_request, + 'Rack::QueryParser::ParameterTypeError' => :bad_request, + 'Rack::QueryParser::InvalidParameterError' => :bad_request, + 'ActiveRecord::RecordNotFound' => :not_found, + 'ActiveRecord::StaleObjectError' => :conflict, + 'ActiveRecord::RecordInvalid' => :unprocessable_entity, + 'ActiveRecord::RecordNotSaved' => :unprocessable_entity } ``` @@ -403,15 +530,15 @@ encrypted cookies salt value. Defaults to `'signed encrypted cookie'`. * `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`. - * `ActionDispatch::Callbacks.after` takes a block of code to run after the request. ### Configuring Action View `config.action_view` includes a small number of configuration settings: -* `config.action_view.field_error_proc` provides an HTML generator for displaying errors that come from Active Record. The default is +* `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.action_view.field_error_proc` provides an HTML generator for displaying errors that come from Active Model. The default is ```ruby Proc.new do |html_tag, instance| @@ -419,13 +546,23 @@ encrypted cookies salt value. Defaults to `'signed encrypted cookie'`. end ``` -* `config.action_view.default_form_builder` tells Rails which form builder to use by default. The default is `ActionView::Helpers::FormBuilder`. If you want your form builder class to be loaded after initialization (so it's reloaded on each request in development), you can pass it as a `String` +* `config.action_view.default_form_builder` tells Rails which form builder to + use by default. The default is `ActionView::Helpers::FormBuilder`. If you + want your form builder class to be loaded after initialization (so it's + reloaded on each request in development), you can pass it as a `String`. * `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 `'-'`, 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.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::ArticlesController` which renders this template: @@ -435,7 +572,17 @@ encrypted cookies salt value. Defaults to `'signed encrypted cookie'`. 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 +* `config.action_view.raise_on_missing_translations` determines whether an + error should be raised for missing translations. + +* `config.action_view.automatically_disable_submit_tag` determines whether + `submit_tag` should automatically disable on click, this defaults to `true`. + +* `config.action_view.debug_missing_translation` determines whether to wrap the missing translations key in a `<span>` tag or not. This defaults to `true`. + +* `config.action_view.form_with_generates_remote_forms` determines whether `form_with` generates remote forms or not. This defaults to `true`. + +* `config.action_view.form_with_generates_ids` determines whether `form_with` generates ids on inputs. This defaults to `true`. ### Configuring Action Mailer @@ -450,16 +597,19 @@ There are a number of settings available on `config.action_mailer`: * `:user_name` - If your mail server requires authentication, set the username in this setting. * `:password` - If your mail server requires authentication, set the password in this setting. * `: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`. + * `:enable_starttls_auto` - Detects if STARTTLS is enabled in your SMTP server and starts to use it. It defaults to `true`. + * `:openssl_verify_mode` - When using TLS, you can set how OpenSSL checks the certificate. This is useful if you need to validate a self-signed and/or a wildcard certificate. This can be one of the OpenSSL verify constants, `:none` or `:peer` -- or the constant directly `OpenSSL::SSL::VERIFY_NONE` or `OpenSSL::SSL::VERIFY_PEER`, respectively. + * `:ssl/:tls` - Enables the SMTP connection to use SMTP/TLS (SMTPS: SMTP over direct TLS connection). * `config.action_mailer.sendmail_settings` allows detailed configuration for the `sendmail` delivery method. It accepts a hash of options, which can include any of these options: * `:location` - The location of the sendmail executable. Defaults to `/usr/sbin/sendmail`. - * `:arguments` - The command line arguments. Defaults to `-i -t`. + * `:arguments` - The command line arguments. Defaults to `-i`. -* `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.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 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.delivery_method` defines the delivery method and defaults to `:smtp`. See the [configuration section in the Action Mailer guide](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.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: @@ -502,22 +652,26 @@ There are a number of settings available on `config.action_mailer`: config.action_mailer.show_previews = false ``` +* `config.action_mailer.deliver_later_queue_name` specifies the queue name for + mailers. By default this is `mailers`. + +* `config.action_mailer.perform_caching` specifies whether the mailer templates should perform fragment caching or not. By default this is `false` in all environments. + + ### 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.test_order` sets the order in which the test cases are executed. Possible values are `:random` and `:sorted`. Defaults to `:random`. -* `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.escape_html_entities_in_json` enables or disables the escaping of HTML entities in JSON serialization. Defaults to `true`. * `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`. -* `config.active_support.halt_callback_chains_on_return_false` specifies whether ActiveRecord, ActiveModel and ActiveModel::Validations callback chains can be halted by returning `false` in a 'before' callback. Defaults to `true`. - * `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. @@ -528,6 +682,69 @@ There are a few configuration options available in Active Support: * `ActiveSupport::Deprecation.silenced` sets whether or not to display deprecation warnings. +### Configuring Active Job + +`config.active_job` provides the following configuration options: + +* `config.active_job.queue_adapter` sets the adapter for the queueing backend. The default adapter is `:async`. For an up-to-date list of built-in adapters see the [ActiveJob::QueueAdapters API documentation](http://api.rubyonrails.org/classes/ActiveJob/QueueAdapters.html). + + ```ruby + # 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 + ``` + +* `config.active_job.default_queue_name` can be used to change the default queue name. By default this is `"default"`. + + ```ruby + config.active_job.default_queue_name = :medium_priority + ``` + +* `config.active_job.queue_name_prefix` allows you to set an optional, non-blank, queue name prefix for all jobs. By default it is blank and not used. + + The following configuration would queue the given job on the `production_high_priority` queue when run in production: + + ```ruby + config.active_job.queue_name_prefix = Rails.env + ``` + + ```ruby + class GuestsCleanupJob < ActiveJob::Base + queue_as :high_priority + #.... + end + ``` + +* `config.active_job.queue_name_delimiter` has a default value of `'_'`. If `queue_name_prefix` is set, then `queue_name_delimiter` joins the prefix and the non-prefixed queue name. + + The following configuration would queue the provided job on the `video_server.low_priority` queue: + + ```ruby + # prefix must be set for delimiter to be used + config.active_job.queue_name_prefix = 'video_server' + config.active_job.queue_name_delimiter = '.' + ``` + + ```ruby + class EncoderJob < ActiveJob::Base + queue_as :low_priority + #.... + end + ``` + +* `config.active_job.logger` accepts a logger conforming to the interface of Log4r or the default Ruby Logger class, which is then used to log information from Active Job. You can retrieve this logger by calling `logger` on either an Active Job class or an Active Job instance. Set to `nil` to disable logging. + +### Configuring Action Cable + +* `config.action_cable.url` accepts a string for the URL for where + you are hosting your Action Cable server. You would use this option +if you are running Action Cable servers that are separated from your +main application. +* `config.action_cable.mount_path` accepts a string for where to mount Action + Cable, as part of the main server process. Defaults to `/cable`. +You can set this as nil to not mount Action Cable as part of your +normal Rails server. ### Configuring a Database @@ -570,7 +787,7 @@ TIP: You don't have to update the database configurations manually. If you look ### Connection Preference -Since there are two ways to set your connection, via environment variable it is important to understand how the two can interact. +Since there are two ways to configure your connection (using `config/database.yml` or using an environment variable) it is important to understand how they 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: @@ -670,11 +887,11 @@ development: timeout: 5000 ``` -NOTE: Rails uses an SQLite3 database for data storage by default because it is a zero configuration database that just works. Rails also supports MySQL and PostgreSQL "out of the box", and has plugins for many database systems. If you are using a database in a production environment Rails most likely has an adapter for it. +NOTE: Rails uses an SQLite3 database for data storage by default because it is a zero configuration database that just works. Rails also supports MySQL (including MariaDB) and PostgreSQL "out of the box", and has plugins for many database systems. If you are using a database in a production environment Rails most likely has an adapter for it. -#### Configuring a MySQL Database +#### Configuring a MySQL or MariaDB Database -If you choose to use MySQL instead of the shipped SQLite3 database, your `config/database.yml` will look a little different. Here's the development section: +If you choose to use MySQL or MariaDB instead of the shipped SQLite3 database, your `config/database.yml` will look a little different. Here's the development section: ```yaml development: @@ -687,7 +904,7 @@ development: socket: /tmp/mysql.sock ``` -If your development computer's MySQL installation includes a root user with an empty password, this configuration should work for you. Otherwise, change the username and password in the `development` section as appropriate. +If your development database has a root user with an empty password, this configuration should work for you. Otherwise, change the username and password in the `development` section as appropriate. #### Configuring a PostgreSQL Database @@ -729,9 +946,9 @@ development: database: db/development.sqlite3 ``` -#### Configuring a MySQL Database for JRuby Platform +#### Configuring a MySQL or MariaDB Database for JRuby Platform -If you choose to use MySQL and are using JRuby, your `config/database.yml` will look a little different. Here's the development section: +If you choose to use MySQL or MariaDB and are using JRuby, your `config/database.yml` will look a little different. Here's the development section: ```yaml development: @@ -762,7 +979,7 @@ By default Rails ships with three environments: "development", "test", and "prod 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. +That environment is no different than the default ones, start a server with `rails server -e staging`, a console with `rails console -e staging`, `Rails.env.staging?` works, etc. ### Deploy to a subdirectory (relative url root) @@ -784,7 +1001,7 @@ 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). +Passenger makes it easy to run your application in a subdirectory. You can find the relevant configuration in the [Passenger manual](https://www.phusionpassenger.com/library/deploy/apache/deploy/ruby/#deploying-an-app-to-a-sub-uri-or-subdirectory). #### Using a Reverse Proxy @@ -792,17 +1009,17 @@ Deploying your application using a reverse proxy has definite advantages over tr 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. +One such application server you can use is [Unicorn](https://bogomips.org/unicorn/) 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. +You can find more information in the [Unicorn readme](https://bogomips.org/unicorn/README.html) and understand the [philosophy](https://bogomips.org/unicorn/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 0.0.0.0:8080; } server { @@ -824,17 +1041,8 @@ server { } ``` -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 +Be sure to read the [NGINX documentation](https://nginx.org/en/docs/) for the most up-to-date information. -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 -------------------------- @@ -855,7 +1063,7 @@ After loading the framework and any gems in your application, Rails turns to loa NOTE: You can use subfolders to organize your initializers if you like, because Rails will look into the whole file hierarchy from the initializers folder on down. -TIP: If you have any ordering dependency in your initializers, you can control the load order through naming. Initializer files are loaded in alphabetical order by their path. For example, `01_critical.rb` will be loaded before `02_normal.rb`. +TIP: While Rails supports numbering of initializer file names for load ordering purposes, a better technique is to place any code that need to load in a specific order within the same file. This reduces file name churn, makes dependencies more explicit, and can help surface new concepts within your application. Initialization events --------------------- @@ -918,93 +1126,110 @@ Because `Rails::Application` inherits from `Rails::Railtie` (indirectly), you ca Below is a comprehensive list of all the initializers found in Rails in the order that they are defined (and therefore run in, unless otherwise stated). -* `load_environment_hook` Serves as a placeholder so that `:load_environment_config` can be defined to run before it. +* `load_environment_hook`: Serves as a placeholder so that `:load_environment_config` can be defined to run before it. + +* `load_active_support`: Requires `active_support/dependencies` which sets up the basis for Active Support. Optionally requires `active_support/all` if `config.active_support.bare` is un-truthful, which is the default. -* `load_active_support` Requires `active_support/dependencies` which sets up the basis for Active Support. Optionally requires `active_support/all` if `config.active_support.bare` is un-truthful, which is the default. +* `initialize_logger`: Initializes the logger (an `ActiveSupport::Logger` object) for the application and makes it accessible at `Rails.logger`, provided that no initializer inserted before this point has defined `Rails.logger`. -* `initialize_logger` Initializes the logger (an `ActiveSupport::Logger` object) for the application and makes it accessible at `Rails.logger`, provided that no initializer inserted before this point has defined `Rails.logger`. +* `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. -* `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`: 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. -* `initialize_dependency_mechanism` If `config.cache_classes` is true, configures `ActiveSupport::Dependencies.mechanism` to `require` dependencies rather than `load` them. +* `bootstrap_hook`: Runs all configured `before_initialize` blocks. -* `bootstrap_hook` Runs all configured `before_initialize` blocks. +* `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. -* `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.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.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_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 beginning 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`. +* `active_support.set_configs`: Sets up Active Support by using the settings in `config.active_support` by `send`'ing the method names as setters to `ActiveSupport` and passing the values through. -* `action_dispatch.configure` Configures the `ActionDispatch::Http::URL.tld_length` to be set to the value of `config.action_dispatch.tld_length`. +* `action_dispatch.configure`: Configures the `ActionDispatch::Http::URL.tld_length` to be set to the value of `config.action_dispatch.tld_length`. -* `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_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.assets_config`: Initializes the `config.actions_controller.assets_dir` to the app's public directory if not explicitly configured. -* `action_controller.initialize_framework_caches` Sets `ActionController::Base.cache_store` - if it's not already set - to `Rails.cache`. +* `action_controller.set_helpers_path`: Sets Action Controller's `helpers_path` to the application's `helpers_path`. -* `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. +* `action_controller.parameters_config`: Configures strong parameters options for `ActionController::Parameters`. -* `action_controller.compile_config_methods` Initializes methods for the config settings specified so that they are quicker to access. +* `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. -* `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`. +* `action_controller.compile_config_methods`: Initializes methods for the config settings specified so that they are quicker to access. -* `active_record.logger` Sets `ActiveRecord::Base.logger` - if it's not already set - to `Rails.logger`. +* `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.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. +* `active_record.logger`: Sets `ActiveRecord::Base.logger` - if it's not already set - to `Rails.logger`. -* `active_record.initialize_database` Loads the database configuration (by default) from `config/database.yml` and establishes a connection for the current environment. +* `active_record.migration_error`: Configures middleware to check for pending migrations. -* `active_record.log_runtime` Includes `ActiveRecord::Railties::ControllerRuntime` which is responsible for reporting the time taken by Active Record calls for the request back to the logger. +* `active_record.check_schema_cache_dump`: Loads the schema cache dump if configured and available. -* `active_record.set_dispatch_hooks` Resets all reloadable connections to the database if `config.cache_classes` is set to `false`. +* `active_record.warn_on_records_fetched_greater_than`: Enables warnings when queries return large numbers of records. -* `action_mailer.logger` Sets `ActionMailer::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. -* `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. +* `active_record.initialize_database`: Loads the database configuration (by default) from `config/database.yml` and establishes a connection for the current environment. -* `action_mailer.compile_config_methods` Initializes methods for the config settings specified so that they are quicker to access. +* `active_record.log_runtime`: Includes `ActiveRecord::Railties::ControllerRuntime` which is responsible for reporting the time taken by Active Record calls for the request back to the logger. -* `set_load_path` This initializer runs before `bootstrap_hook`. Adds the `vendor`, `lib`, all directories of `app` and any paths specified by `config.load_paths` to `$LOAD_PATH`. +* `active_record.set_reloader_hooks`: Resets all reloadable connections to the database if `config.cache_classes` is set to `false`. -* `set_autoload_paths` This initializer runs before `bootstrap_hook`. Adds all sub-directories of `app` and paths specified by `config.autoload_paths` to `ActiveSupport::Dependencies.autoload_paths`. +* `active_record.add_watchable_files`: Adds `schema.rb` and `structure.sql` files to watchable files. -* `add_routing_paths` Loads (by default) all `config/routes.rb` files (in the application and railties, including engines) and sets up the routes for the application. +* `active_job.logger`: Sets `ActiveJob::Base.logger` - if it's not already set - + to `Rails.logger`. -* `add_locales` Adds the files in `config/locales` (from the application, railties and engines) to `I18n.load_path`, making available the translations in these files. +* `active_job.set_configs`: Sets up Active Job by using the settings in `config.active_job` by `send`'ing the method names as setters to `ActiveJob::Base` and passing the values through. -* `add_view_paths` Adds the directory `app/views` from the application, railties and engines to the lookup path for view files for the application. +* `action_mailer.logger`: Sets `ActionMailer::Base.logger` - if it's not already set - to `Rails.logger`. -* `load_environment_config` Loads the `config/environments` file for the current environment. +* `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. -* `prepend_helpers_path` Adds the directory `app/helpers` from the application, railties and engines to the lookup path for helpers for the application. +* `action_mailer.compile_config_methods`: Initializes methods for the config settings specified so that they are quicker to access. -* `load_config_initializers` Loads all Ruby files from `config/initializers` in the application, railties and engines. The files in this directory can be used to hold configuration settings that should be made after all of the frameworks are loaded. +* `set_load_path`: This initializer runs before `bootstrap_hook`. Adds paths specified by `config.load_paths` and all autoload paths to `$LOAD_PATH`. -* `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. +* `set_autoload_paths`: This initializer runs before `bootstrap_hook`. Adds all sub-directories of `app` and paths specified by `config.autoload_paths`, `config.eager_load_paths` and `config.autoload_once_paths` to `ActiveSupport::Dependencies.autoload_paths`. -* `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. +* `add_routing_paths`: Loads (by default) all `config/routes.rb` files (in the application and railties, including engines) and sets up the routes for the application. -* `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_locales`: Adds the files in `config/locales` (from the application, railties and engines) to `I18n.load_path`, making available the translations in these files. -* `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_view_paths`: Adds the directory `app/views` from the application, railties and engines to the lookup path for view files for the application. -* `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. +* `load_environment_config`: Loads the `config/environments` file for the current environment. -* `build_middleware_stack` Builds the middleware stack for the application, returning an object which has a `call` method which takes a Rack environment object for the request. +* `prepend_helpers_path`: Adds the directory `app/helpers` from the application, railties and engines to the lookup path for helpers for the application. -* `eager_load!` If `config.eager_load` is true, runs the `config.before_eager_load` hooks and then calls `eager_load!` which will load all `config.eager_load_namespaces`. +* `load_config_initializers`: Loads all Ruby files from `config/initializers` in the application, railties and engines. The files in this directory can be used to hold configuration settings that should be made after all of the frameworks are loaded. -* `finisher_hook` Provides a hook for after the initialization of process of the application is complete, as well as running all the `config.after_initialize` blocks for the application, railties and engines. +* `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. -* `set_routes_reloader` Configures Action Dispatch to reload the routes file using `ActionDispatch::Callbacks.to_prepare`. +* `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. -* `disable_dependency_loading` Disables the automatic dependency loading if the `config.eager_load` is set to true. +* `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 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. + +* `build_middleware_stack`: Builds the middleware stack for the application, returning an object which has a `call` method which takes a Rack environment object for the request. + +* `eager_load!`: If `config.eager_load` is `true`, runs the `config.before_eager_load` hooks and then calls `eager_load!` which will load all `config.eager_load_namespaces`. + +* `finisher_hook`: Provides a hook for after the initialization of process of the application is complete, as well as running all the `config.after_initialize` blocks for the application, railties and engines. + +* `set_routes_reloader_hook`: Configures Action Dispatch to reload the routes file using `ActiveSupport::Callbacks.to_run`. + +* `disable_dependency_loading`: Disables the automatic dependency loading if the `config.eager_load` is set to `true`. Database pooling ---------------- @@ -1019,33 +1244,37 @@ development: timeout: 5000 ``` -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. +Since the connection pooling is handled inside of Active Record by default, all application servers (Thin, Puma, Unicorn etc.) should behave the same. The database connection pool is initially empty. As demand for connections increases it will create them 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. +Any one request will check out a connection the first time it requires access to the database. At the end of the request it will check the connection back in. This means that the additional connection slot will be available again for the next request in the queue. 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. +you and wait for a connection from the pool. If it cannot get a connection, a +timeout error similar to that 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: +ActiveRecord::ConnectionTimeoutError - could not obtain a database connection within 5.000 seconds (waited 5.000 seconds) ``` -If you get the above error, you might want to increase the size of connection -pool by incrementing the `pool` option in `database.yml` +If you get the above error, you might want to increase the size of the +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. +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 number of connections. Custom configuration -------------------- -You can configure your own code through the Rails configuration object with custom configuration. It works like this: +You can configure your own code through the Rails configuration object with +custom configuration under either the `config.x` namespace, or `config` directly. +The key difference between these two is that you should be using `config.x` if you +are defining _nested_ configuration (ex: `config.x.nested.nested.hi`), and just +`config` for _single level_ configuration (ex: `config.hello`). ```ruby config.x.payment_processing.schedule = :daily config.x.payment_processing.retries = 3 - config.x.super_debugger = true + config.super_debugger = true ``` These configuration points are then available through the configuration object: @@ -1053,8 +1282,35 @@ 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 + Rails.configuration.x.payment_processing.not_set # => nil + Rails.configuration.super_debugger # => true + ``` + +You can also use `Rails::Application.config_for` to load whole configuration files: + + ```ruby + # config/payment.yml: + production: + environment: production + merchant_id: production_merchant_id + public_key: production_public_key + private_key: production_private_key + development: + environment: sandbox + merchant_id: development_merchant_id + public_key: development_public_key + private_key: development_private_key + + # config/application.rb + module MyApp + class Application < Rails::Application + config.payment = config_for(:payment) + end + end + ``` + + ```ruby + Rails.configuration.payment['merchant_id'] # => production_merchant_id or development_merchant_id ``` Search Engines Indexing @@ -1062,12 +1318,12 @@ Search Engines Indexing Sometimes, you may want to prevent some pages of your application to be visible on search sites like Google, Bing, Yahoo or Duck Duck Go. The robots that index -these sites will first analyse the `http://your-site.com/robots.txt` file to +these sites will first analyze the `http://your-site.com/robots.txt` file to know which pages it is allowed to index. Rails creates this file for you inside the `/public` folder. By default, it allows search engines to index all pages of your application. If you want to block -indexing on all pages of you application, use this: +indexing on all pages of your application, use this: ``` User-agent: * @@ -1076,3 +1332,25 @@ Disallow: / To block just specific pages, it's necessary to use a more complex syntax. Learn it on the [official documentation](http://www.robotstxt.org/robotstxt.html). + +Evented File System Monitor +--------------------------- + +If the [listen gem](https://github.com/guard/listen) is loaded Rails uses an +evented file system monitor to detect changes when `config.cache_classes` is +`false`: + +```ruby +group :development do + gem 'listen', '>= 3.0.5', '< 3.2' +end +``` + +Otherwise, in every request Rails walks the application tree to check if +anything has changed. + +On Linux and macOS no additional gems are needed, but some are required +[for *BSD](https://github.com/guard/listen#on-bsd) and +[for Windows](https://github.com/guard/listen#on-windows). + +Note that [some setups are unsupported](https://github.com/guard/listen#issues--limitations). diff --git a/guides/source/contributing_to_ruby_on_rails.md b/guides/source/contributing_to_ruby_on_rails.md index 018100c316..967c992c05 100644 --- a/guides/source/contributing_to_ruby_on_rails.md +++ b/guides/source/contributing_to_ruby_on_rails.md @@ -13,7 +13,10 @@ 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, thousands 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. + +As mentioned in [Rails' +README](https://github.com/rails/rails/blob/master/README.md), everyone interacting in Rails and its sub-projects' codebases, issue trackers, chat rooms, and mailing lists is expected to follow the Rails [code of conduct](http://rubyonrails.org/conduct/). -------------------------------------------------------------------------------- @@ -22,25 +25,31 @@ Reporting an Issue Ruby on Rails uses [GitHub Issue Tracking](https://github.com/rails/rails/issues) to track issues (primarily bugs and contributions of new code). If you've found a bug in Ruby on Rails, this is the place to start. You'll need to create a (free) GitHub account in order to submit an issue, to comment on them or to create pull requests. -NOTE: Bugs in the most recent released version of Ruby on Rails are likely to get the most attention. Also, the Rails core team is always interested in feedback from those who can take the time to test _edge Rails_ (the code for the version of Rails that is currently under development). Later in this guide you'll find out how to get edge Rails for testing. +NOTE: Bugs in the most recent released version of Ruby on Rails are likely to get the most attention. Also, the Rails core team is always interested in feedback from those who can take the time to test _edge Rails_ (the code for the version of Rails that is currently under development). Later in this guide, you'll find out how to get edge Rails for testing. ### Creating a Bug Report If you've found a problem in Ruby on Rails which is not a security risk, do a search on 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.) -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. +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 reproduce 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 +### Create an Executable Test Case + +Having a way to reproduce your issue will be very helpful for others to help confirm, investigate and ultimately fix your issue. You can do this by providing an executable test case. To make this process easier, we have prepared several bug report templates for you to use as a starting point: + +* Template for Active Record (models, database) issues: [gem](https://github.com/rails/rails/blob/master/guides/bug_report_templates/active_record_gem.rb) / [master](https://github.com/rails/rails/blob/master/guides/bug_report_templates/active_record_master.rb) +* Template for testing Active Record (migration) issues: [gem](https://github.com/rails/rails/blob/master/guides/bug_report_templates/active_record_migrations_gem.rb) / [master](https://github.com/rails/rails/blob/master/guides/bug_report_templates/active_record_migrations_master.rb) +* Template for Action Pack (controllers, routing) issues: [gem](https://github.com/rails/rails/blob/master/guides/bug_report_templates/action_controller_gem.rb) / [master](https://github.com/rails/rails/blob/master/guides/bug_report_templates/action_controller_master.rb) +* Template for Active Job issues: [gem](https://github.com/rails/rails/blob/master/guides/bug_report_templates/active_job_gem.rb) / [master](https://github.com/rails/rails/blob/master/guides/bug_report_templates/active_job_master.rb) +* Generic template for other issues: [gem](https://github.com/rails/rails/blob/master/guides/bug_report_templates/generic_gem.rb) / [master](https://github.com/rails/rails/blob/master/guides/bug_report_templates/generic_master.rb) + +These templates include the boilerplate code to set up a test case against either a released version of Rails (`*_gem.rb`) or edge Rails (`*_master.rb`). + +Simply copy the content of the appropriate template into a `.rb` file and make the necessary changes to demonstrate the issue. You can execute it by running `ruby the_file.rb` in your terminal. If all goes well, you should see your test case failing. -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. +You can then share your executable test case as a [gist](https://gist.github.com), or simply paste the content into the issue description. ### Special Treatment for Security Issues @@ -51,18 +60,18 @@ WARNING: Please do not report security vulnerabilities with public GitHub issue 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 +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 +anything that causes incorrect behavior. Sometimes, +the core team will have to make a judgment 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 +If you'd like feedback on an idea for a feature before doing the work to 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 @@ -75,30 +84,32 @@ discussions new features require. Helping to Resolve Existing Issues ---------------------------------- -As a next step beyond reporting issues, you can help the core team resolve existing issues. If you check the [Everyone's Issues](https://github.com/rails/rails/issues) list in GitHub Issues, you'll find lots of issues already requiring attention. What can you do for these? Quite a bit, actually: +As a next step beyond reporting issues, you can help the core team resolve existing ones by providing feedback about them. If you are new to Rails core development, that might be a great way to walk your first steps, you'll get familiar with the code base and the processes. + +If you check the [issues list](https://github.com/rails/rails/issues) in GitHub Issues, you'll find lots of issues already requiring attention. What can you do for these? Quite a bit, actually: ### Verifying Bug Reports For starters, it helps just to verify bug reports. Can you reproduce the reported issue on your own computer? If so, you can add a comment to the issue saying that you're seeing the same thing. -If something is very vague, can you help squash it down into something specific? Maybe you can provide additional information to help reproduce a bug, or help by eliminating needless steps that aren't required to demonstrate the problem. +If an issue is very vague, can you help narrow it down to something more specific? Maybe you can provide additional information to help reproduce a bug, or help by eliminating needless steps that aren't required to demonstrate the problem. -If you find a bug report without a test, it's very useful to contribute a failing test. This is also a great way to get started exploring the source code: looking at the existing test files will teach you how to write more tests. New tests are best contributed in the form of a patch, as explained later on in the "Contributing to the Rails Code" section. +If you find a bug report without a test, it's very useful to contribute a failing test. This is also a great way to get started exploring the source code: looking at the existing test files will teach you how to write more tests. New tests are best contributed in the form of a patch, as explained later on in the "[Contributing to the Rails Code](#contributing-to-the-rails-code)" section. -Anything you can do to make bug reports more succinct or easier to reproduce is a help to folks trying to write code to fix those bugs - whether you end up writing the code yourself or not. +Anything you can do to make bug reports more succinct or easier to reproduce helps folks trying to write code to fix those bugs - whether you end up writing the code yourself or not. ### Testing Patches -You can also help out by examining pull requests that have been submitted to Ruby on Rails via GitHub. To apply someone's changes you need first to create a dedicated branch: +You can also help out by examining pull requests that have been submitted to Ruby on Rails via GitHub. In order to apply someone's changes, you need to first create a dedicated branch: ```bash $ git checkout -b testing_branch ``` -Then you can use their remote branch to update your codebase. For example, let's say the GitHub user JohnSmith has forked and pushed to a topic branch "orange" located at https://github.com/JohnSmith/rails. +Then, you can use their remote branch to update your codebase. For example, let's say the GitHub user JohnSmith has forked and pushed to a topic branch "orange" located at https://github.com/JohnSmith/rails. ```bash -$ git remote add JohnSmith git://github.com/JohnSmith/rails.git +$ git remote add JohnSmith https://github.com/JohnSmith/rails.git $ git pull JohnSmith orange ``` @@ -113,7 +124,7 @@ Once you're happy that the pull request contains a good change, comment on the G >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. +If your comment simply reads "+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 --------------------------------------- @@ -121,36 +132,61 @@ Contributing to the Rails Documentation 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 them up to date with the latest edge Rails. -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. +To do so, open a pull request to [Rails](https://github.com/rails/rails) on GitHub. -Docrails is merged with master regularly, so you are effectively editing the Ruby on Rails documentation. +When working with documentation, please take into account the [API Documentation Guidelines](api_documentation_guidelines.html) and the [Ruby on Rails Guides Guidelines](ruby_on_rails_guides_guidelines.html). -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. +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. -When working with documentation, please take into account the [API Documentation Guidelines](api_documentation_guidelines.html) and the [Ruby on Rails Guides Guidelines](ruby_on_rails_guides_guidelines.html). +Translating Rails Guides +------------------------ -NOTE: As explained earlier, ordinary code patches should have proper documentation coverage. Docrails is only used for isolated documentation improvements. +We are happy to have people volunteer to translate the Rails guides. Just follow these steps: -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. +* Fork https://github.com/rails/rails. +* Add a source folder for your own language, for example: *guides/source/it-IT* for Italian. +* Copy the contents of *guides/source* into your own language directory and translate them. +* Do NOT translate the HTML files, as they are automatically generated. + +Note that translations are not submitted to the Rails repository. As detailed above, your work happens in a fork. This is so because in practice documentation maintenance via patches is only sustainable in English. + +To generate the guides in HTML format cd into the *guides* directory then run (eg. for it-IT): + +```bash +$ bundle install +$ bundle exec rake guides:generate:html GUIDES_LANGUAGE=it-IT +``` + +This will generate the guides in an *output* directory. -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. +NOTE: The instructions are for Rails > 4. The Redcarpet Gem doesn't work with JRuby. + +Translation efforts we know about (various versions): + +* **Italian**: [https://github.com/rixlabs/docrails](https://github.com/rixlabs/docrails) +* **Spanish**: [https://github.com/gramos/docrails/wiki](https://github.com/gramos/docrails/wiki) +* **Polish**: [https://github.com/apohllo/docrails](https://github.com/apohllo/docrails) +* **French** : [https://github.com/railsfrance/docrails](https://github.com/railsfrance/docrails) +* **Czech** : [https://github.com/rubyonrails-cz/docrails/tree/czech](https://github.com/rubyonrails-cz/docrails/tree/czech) +* **Turkish** : [https://github.com/ujk/docrails](https://github.com/ujk/docrails) +* **Korean** : [https://github.com/rorlakr/rails-guides](https://github.com/rorlakr/rails-guides) +* **Simplified Chinese** : [https://github.com/ruby-china/guides](https://github.com/ruby-china/guides) +* **Traditional Chinese** : [https://github.com/docrails-tw/guides](https://github.com/docrails-tw/guides) +* **Russian** : [https://github.com/morsbox/rusrails](https://github.com/morsbox/rusrails) +* **Japanese** : [https://github.com/yasslab/railsguides.jp](https://github.com/yasslab/railsguides.jp) 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. +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 easiest and recommended way to get a development environment ready to hack is to use the [rails-dev-box](https://github.com/rails/rails-dev-box). #### The Hard Way @@ -161,7 +197,7 @@ In case you can't use the Rails development box, see [this other guide](developm To be able to contribute code, you need to clone the Rails repository: ```bash -$ git clone git://github.com/rails/rails.git +$ git clone https://github.com/rails/rails.git ``` and create a dedicated branch: @@ -225,40 +261,31 @@ 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 132.013k i/100ms - addition with send 125.413k i/100ms -------------------------------------------------- - addition 9.677M (± 1.7%) i/s - 48.449M - addition with send 6.794M (± 1.1%) i/s - 33.987M -``` - -Please see the benchmark/ips [README](https://github.com/evanphx/benchmark-ips/blob/master/README.md) for more information. +For changes that might have an impact on performance, please benchmark your +code and measure the impact. Please share the benchmark script you used as well +as the results. You should consider including this information in your commit +message, which allows future contributors to easily verify your findings and +determine if they are still relevant. (For example, future optimizations in the +Ruby VM might render certain optimizations unnecessary.) + +It is very easy to make an optimization that improves performance for a +specific scenario you care about but regresses on other common cases. +Therefore, you should test your change against a list of representative +scenarios. Ideally, they should be based on real-world scenarios extracted +from production applications. + +You can use the [benchmark template](https://github.com/rails/rails/blob/master/guides/bug_report_templates/benchmark.rb) +as a starting point. It includes the boilerplate code to setup a benchmark +using the [benchmark-ips](https://github.com/evanphx/benchmark-ips) gem. The +template is designed for testing relatively self-contained changes that can be +inlined into the script. ### 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). +changes. The railties test suite in particular takes a long time, and takes an +especially long time 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 @@ -291,7 +318,7 @@ 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 +$ bundle exec 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 @@ -299,10 +326,12 @@ 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. +First, create the databases you'll need. You can find a list of the required +table names, usernames, and passwords in `activerecord/test/config.example.yml`. + +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: @@ -311,10 +340,9 @@ $ cd activerecord $ bundle exec rake test:sqlite3 ``` -You can now run the tests as you did for `sqlite3`. The tasks are respectively +You can now run the tests as you did for `sqlite3`. The tasks are respectively: ```bash -test:mysql test:mysql2 test:postgresql ``` @@ -325,12 +353,12 @@ Finally, $ bundle exec rake test ``` -will now run the four of them in turn. +will now run the three 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 +$ ARCONN=sqlite3 bundle exec ruby -Itest test/cases/associations/has_many_associations_test.rb ``` To run a single test against all adapters, use: @@ -355,9 +383,9 @@ $ RUBYOPT=-W0 bundle exec rake test 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, committing 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 top** of 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 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: +A CHANGELOG entry should summarize what was changed and should end with the 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 the issue's number. Here is an example CHANGELOG entry: ``` * Summary of a change that briefly describes what was changed. You can use multiple @@ -374,22 +402,13 @@ A CHANGELOG entry should summarize what was changed and should end with author's *Your Name* ``` -Your name can be added directly after the last word if you don't provide any code examples or don't need multiple paragraphs. Otherwise, it's best to make as a new paragraph. +Your name can be added directly after the last word if there are no code +examples or multiple paragraphs. Otherwise, it's best to make a new paragraph. ### Updating the Gemfile.lock Some changes require the dependencies to be upgraded. In these cases make sure you run `bundle update` to get the right version of the dependency and commit the `Gemfile.lock` file within your changes. -### Sanity Check - -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 When you're happy with the code on your computer, you need to commit the changes to Git: @@ -398,21 +417,27 @@ When you're happy with the code on your computer, you need to commit the changes $ git commit -a ``` -At this point, your editor should be fired up and you can write a message for this commit. Well formatted and descriptive commit messages are extremely helpful for the others, especially when figuring out why given change was made, so please take the time to write it. +This should fire up your editor to write a commit message. When you have +finished, save and close to continue. -Good commit message should be formatted according to the following example: +A well-formatted and descriptive commit message is very helpful to others for +understanding why the change was made, so please take the time to write it. + +A good commit message looks like this: ``` Short summary (ideally 50 characters or less) -More detailed description, if necessary. It should be wrapped to 72 -characters. Try to be as descriptive as you can, even if you think that -the commit content is obvious, it may not be obvious to others. You -should add such description also if it's already present in bug tracker, -it should not be necessary to visit a webpage to check the history. +More detailed description, if necessary. It should be wrapped to +72 characters. Try to be as descriptive as you can. Even if you +think that the commit content is obvious, it may not be obvious +to others. Add any description that is already present in the +relevant issues; it should not be necessary to visit a webpage +to check the history. + +The description section can have multiple paragraphs. -Description can have multiple paragraphs and you can use code examples -inside, just indent it with 4 spaces: +Code examples can be embedded by indenting them with 4 spaces: class ArticlesController def index @@ -422,13 +447,15 @@ inside, just indent it with 4 spaces: You can also add bullet points: -- you can use dashes or asterisks +- make a bullet point by starting a line with either a dash (-) + or an asterisk (*) -- also, try to indent next line of a point for readability, if it's too - long to fit in 72 characters +- wrap lines at 72 characters, and indent any additional lines + with 2 spaces for readability ``` -TIP. Please squash your commits into a single commit when appropriate. This simplifies future cherry picks, and also keeps the git log clean. +TIP. Please squash your commits into a single commit when appropriate. This +simplifies future cherry picks and keeps the git log clean. ### Update Your Branch @@ -455,7 +482,7 @@ Navigate to the Rails [GitHub repository](https://github.com/rails/rails) and pr Add the new remote to your local repository on your local machine: ```bash -$ git remote add mine git@github.com:<your user name>/rails.git +$ git remote add mine https://github.com/<your user name>/rails.git ``` Push to your remote: @@ -469,7 +496,7 @@ You might have cloned your forked repository into your machine and might want to In the directory you cloned your fork: ```bash -$ git remote add rails git://github.com/rails/rails.git +$ git remote add rails https://github.com/rails/rails.git ``` Download new commits and branches from the official repository: @@ -519,7 +546,7 @@ pull request". The Rails core team will be notified about your submission. 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. +patches will need to be 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 @@ -529,7 +556,7 @@ 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 +list](https://groups.google.com/forum/#!forum/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 @@ -566,8 +593,7 @@ following: ```bash $ git fetch upstream $ git checkout my_pull_request -$ git rebase upstream/master -$ git rebase -i +$ git rebase -i upstream/master < Choose 'squash' for all of your commits except the first one. > < Edit the commit message to make sense, and describe all your changes. > @@ -612,7 +638,7 @@ Changes that are merged into master are intended for the next major release of R For simple fixes, the easiest way to backport your changes is to [extract a diff from your changes in master and apply them to the target branch](http://ariejan.net/2009/10/26/how-to-create-and-apply-a-patch-with-git). -First make sure your changes are the only difference between your current branch and master: +First, make sure your changes are the only difference between your current branch and master: ```bash $ git log master..HEAD @@ -627,7 +653,7 @@ $ git format-patch master --stdout > ~/my_changes.patch Switch over to the target branch and apply your changes: ```bash -$ git checkout -b my_backport_branch 3-2-stable +$ git checkout -b my_backport_branch 4-2-stable $ git apply ~/my_changes.patch ``` @@ -640,4 +666,4 @@ And then... think about your next contribution! Rails Contributors ------------------ -All contributions, either via master or docrails, get credit in [Rails Contributors](http://contributors.rubyonrails.org). +All contributions get credit in [Rails Contributors](http://contributors.rubyonrails.org). diff --git a/guides/source/credits.html.erb b/guides/source/credits.html.erb index 61ea0b44ef..5adbd12ac0 100644 --- a/guides/source/credits.html.erb +++ b/guides/source/credits.html.erb @@ -22,17 +22,17 @@ Ruby on Rails Guides: Credits <h3 class="section">Rails Guides Designers</h3> <%= author('Jason Zimdars', 'jz') do %> - Jason Zimdars is an experienced creative director and web designer who has lead UI and UX design for numerous websites and web applications. You can see more of his design and writing at <a href="http://www.thinkcage.com/">Thinkcage.com</a> or follow him on <a href="http://twitter.com/JZ">Twitter</a>. + Jason Zimdars is an experienced creative director and web designer who has lead UI and UX design for numerous websites and web applications. You can see more of his design and writing at <a href="http://www.thinkcage.com/">Thinkcage.com</a> or follow him on <a href="https://twitter.com/jasonzimdars">Twitter</a>. <% end %> <h3 class="section">Rails Guides Authors</h3> <%= author('Ryan Bigg', 'radar', 'radar.png') do %> - 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>. + Ryan Bigg works as a Rails developer at <a href="http://marketplacer.com">Marketplacer</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.businessinsider.com/google-buys-wildfire-2012-8">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 %> @@ -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="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>. + Pratik Naik is a Ruby on Rails developer at <a href="https://basecamp.com/">Basecamp</a> and maintains a blog at <a href="http://m.onkey.org">has_many :bugs, :through => :rails</a>. He also has a semi-active <a href="http://twitter.com/lifo">twitter account</a>. <% end %> <%= author('Emilio Tagua', 'miloops') do %> diff --git a/guides/source/debugging_rails_applications.md b/guides/source/debugging_rails_applications.md index a9715fb837..07c78be3db 100644 --- a/guides/source/debugging_rails_applications.md +++ b/guides/source/debugging_rails_applications.md @@ -17,7 +17,7 @@ After reading this guide, you will know: View Helpers for Debugging -------------------------- -One common task is to inspect the contents of a variable. In Rails, you can do this with three methods: +One common task is to inspect the contents of a variable. Rails provides three different ways to do this: * `debug` * `to_yaml` @@ -54,7 +54,7 @@ Title: Rails debugging guide ### `to_yaml` -Displaying an instance variable, or any other object or method, in YAML format can be achieved this way: +Alternatively, calling `to_yaml` on any object converts it to YAML. You can pass this converted object into the `simple_format` helper method to format the output. This is how `debug` does its magic. ```html+erb <%= simple_format @article.to_yaml %> @@ -64,9 +64,7 @@ Displaying an instance variable, or any other object or method, in YAML format c </p> ``` -The `to_yaml` method converts the method to YAML format leaving it more readable, and then the `simple_format` helper is used to render each line as in the console. This is how `debug` method does its magic. - -As a result of this, you will have something like this in your view: +The above code will render something like this: ```yaml --- !ruby/object Article @@ -94,7 +92,7 @@ Another useful method for displaying object values is `inspect`, especially when </p> ``` -Will be rendered as follows: +Will render: ``` [1, 2, 3, 4, 5] @@ -109,36 +107,41 @@ It can also be useful to save information to log files at runtime. Rails maintai ### What is the Logger? -Rails makes use of the `ActiveSupport::Logger` class to write log information. You can also substitute another logger such as `Log4r` if you wish. +Rails makes use of the `ActiveSupport::Logger` class to write log information. Other loggers, such as `Log4r`, may also be substituted. -You can specify an alternative logger in your `environment.rb` or any environment file: +You can specify an alternative logger in `config/application.rb` or any other environment file, for example: ```ruby -Rails.logger = Logger.new(STDOUT) -Rails.logger = Log4r::Logger.new("Application Log") +config.logger = Logger.new(STDOUT) +config.logger = Log4r::Logger.new("Application Log") ``` Or in the `Initializer` section, add _any_ of the following ```ruby -config.logger = Logger.new(STDOUT) -config.logger = Log4r::Logger.new("Application Log") +Rails.logger = Logger.new(STDOUT) +Rails.logger = Log4r::Logger.new("Application 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 -When something is logged it's printed into the corresponding log if the log level of the message is equal or higher than the configured log level. If you want to know the current log level you can call the `Rails.logger.level` method. +When something is logged, it's printed into the corresponding log if the log +level of the message is equal to or higher than the configured log level. If you +want to know the current log level, you can call the `Rails.logger.level` +method. -The available log levels are: `:debug`, `:info`, `:warn`, `:error`, `:fatal`, and `:unknown`, corresponding to the log level numbers from 0 up to 5 respectively. To change the default log level, use +The available log levels are: `:debug`, `:info`, `:warn`, `:error`, `:fatal`, +and `:unknown`, corresponding to the log level numbers from 0 up to 5, +respectively. To change the default log level, use ```ruby config.log_level = :warn # In any environment initializer, or 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. +This is useful when you want to log under development or staging without flooding your production log with unnecessary information. TIP: The default Rails log level is `debug` in all environments. @@ -159,41 +162,41 @@ class ArticlesController < ApplicationController # ... def create - @article = Article.new(params[:article]) + @article = Article.new(article_params) 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) + redirect_to @article, notice: 'Article was successfully created.' else - render action: "new" + render :new end end # ... + + private + def article_params + params.require(:article).permit(:title, :body, :published) + end end ``` Here's an example of the log generated when this controller action is executed: ``` -Processing ArticlesController#create (for 127.0.0.1 at 2008-09-08 11:52:54) [POST] - Session ID: BAh7BzoMY3NyZl9pZCIlMDY5MWU1M2I1ZDRjODBlMzkyMWI1OTg2NWQyNzViZjYiCmZsYXNoSUM6J0FjdGl -vbkNvbnRyb2xsZXI6OkZsYXNoOjpGbGFzaEhhc2h7AAY6CkB1c2VkewA=--b18cd92fba90eacf8137e5f6b3b06c4d724596a4 - Parameters: {"commit"=>"Create", "article"=>{"title"=>"Debugging Rails", - "body"=>"I'm learning how to print in logs!!!", "published"=>"0"}, - "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} +Started POST "/articles" for 127.0.0.1 at 2017-08-20 20:53:10 +0900 +Processing by ArticlesController#create as HTML + Parameters: {"utf8"=>"✓", "authenticity_token"=>"xhuIbSBFytHCE1agHgvrlKnSVIOGD6jltW2tO+P6a/ACjQ3igjpV4OdbsZjIhC98QizWH9YdKokrqxBCJrtoqQ==", "article"=>{"title"=>"Debugging Rails", "body"=>"I'm learning how to print in logs!!!", "published"=>"0"}, "commit"=>"Create Article"} +New article: {"id"=>nil, "title"=>"Debugging Rails", "body"=>"I'm learning how to print in logs!!!", "published"=>false, "created_at"=>nil, "updated_at"=>nil} 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') + (0.1ms) BEGIN + SQL (0.4ms) INSERT INTO "articles" ("title", "body", "published", "created_at", "updated_at") VALUES ($1, $2, $3, $4, $5) RETURNING "id" [["title", "Debugging Rails"], ["body", "I'm learning how to print in logs!!!"], ["published", "f"], ["created_at", "2017-08-20 11:53:10.010435"], ["updated_at", "2017-08-20 11:53:10.010435"]] + (0.3ms) COMMIT 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] +Redirected to http://localhost:3000/articles/1 +Completed 302 Found in 4ms (ActiveRecord: 0.8ms) ``` 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. @@ -202,7 +205,7 @@ Adding extra logging like this makes it easy to search for unexpected or unusual 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. +in Active Support helps you do 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)) @@ -212,34 +215,33 @@ logger.tagged("BCX") { logger.tagged("Jason") { logger.info "Stuff" } } # Logs " ``` ### 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: +Logging will always have a small impact on the performance of your Rails app, + particularly when logging to disk. Additionally, 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: +Another potential pitfall is too many calls to `Logger` 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 +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. +and interpolating the variables. 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 +only evaluated if the output level is the same as — 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 +The contents of the block, and therefore the string interpolation, are only +evaluated if debug is enabled. This performance savings are only really noticeable with large amounts of logging, but it's a good practice to employ. Debugging with the `byebug` gem @@ -253,8 +255,8 @@ 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. +use this guide to learn how to move from the code you have written into the +underlying Rails code. ### Setup @@ -285,7 +287,7 @@ 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: +displayed and the current line will be marked by '=>', like this: ``` [1, 10] in /PathTo/project/app/controllers/articles_controller.rb @@ -310,16 +312,15 @@ processing the entire request. For example: ```bash -=> Booting WEBrick -=> Rails 5.0.0 application starting in development on http://0.0.0.0:3000 +=> Booting Puma +=> Rails 5.1.0 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 - - +Puma starting in single mode... +* Version 3.4.0 (ruby 2.3.1-p112), codename: Owl Bowl Brawl +* Min threads: 5, max threads: 5 +* Environment: development +* Listening on tcp://localhost:3000 +Use Ctrl-C to stop 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 @@ -335,34 +336,57 @@ Processing by ArticlesController#index as HTML 10: respond_to do |format| 11: format.html # index.html.erb 12: format.json { render json: @articles } - (byebug) ``` -Now it's time to explore and dig into your application. A good place to start is +Now it's time to explore your application. A good place to start is by asking the debugger for help. Type: `help` ``` (byebug) help -byebug 2.7.0 - -Type 'help <command-name>' for help on a specific command + break -- Sets breakpoints in the source code + catch -- Handles exception catchpoints + condition -- Sets conditions on breakpoints + continue -- Runs until program ends, hits a breakpoint or reaches a line + debug -- Spawns a subdebugger + delete -- Deletes breakpoints + disable -- Disables breakpoints or displays + display -- Evaluates expressions every time the debugger stops + down -- Moves to a lower frame in the stack trace + edit -- Edits source files + enable -- Enables breakpoints or displays + finish -- Runs the program until frame returns + frame -- Moves to a frame in the call stack + help -- Helps you using byebug + history -- Shows byebug's history of commands + info -- Shows several informations about the program being debugged + interrupt -- Interrupts the program + irb -- Starts an IRB session + kill -- Sends a signal to the current process + list -- Lists lines of source code + method -- Shows methods of an object, class or module + next -- Runs one or more lines of code + pry -- Starts a Pry session + quit -- Exits byebug + restart -- Restarts the debugged program + save -- Saves current byebug session to a file + set -- Modifies byebug settings + show -- Shows byebug settings + source -- Restores a previously saved byebug session + step -- Steps into blocks or methods one or more times + thread -- Commands to manipulate threads + tracevar -- Enables tracing of a global variable + undisplay -- Stops displaying all or some expressions when program stops + untracevar -- Stops tracing a global variable + up -- Moves to a higher frame in the stack trace + var -- Shows variables and its values + where -- Displays the backtrace -Available commands: -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 +(byebug) ``` -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. - -To see the previous ten lines you should type `list-` (or `l-`) +To see the previous ten lines you should type `list-` (or `l-`). ``` (byebug) l- @@ -377,13 +401,12 @@ To see the previous ten lines you should type `list-` (or `l-`) 7 byebug 8 @articles = Article.find_recent 9 - 10 respond_to do |format| - + 10 respond_to do |format| ``` -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=` +This way you can move inside the file and see the code above the line where you +added the `byebug` call. Finally, to see where you are in the code again you can +type `list=` ``` (byebug) list= @@ -399,7 +422,6 @@ the code again you can type `list=` 10: respond_to do |format| 11: format.html # index.html.erb 12: format.json { render json: @articles } - (byebug) ``` @@ -411,8 +433,7 @@ 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. +debugged program, and know 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 @@ -422,46 +443,45 @@ 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 + at /PathToProject/app/controllers/articles_controller.rb:8 + #1 ActionController::BasicImplicitRender.send_action(method#String, *args#Array) + at /PathToGems/actionpack-5.1.0/lib/action_controller/metal/basic_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 + at /PathToGems/actionpack-5.1.0/lib/abstract_controller/base.rb:181 + #3 ActionController::Rendering.process_action(action, *args) + at /PathToGems/actionpack-5.1.0/lib/action_controller/metal/rendering.rb:30 ... ``` 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 +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. ``` (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, - +[176, 185] in /PathToGems/actionpack-5.1.0/lib/abstract_controller/base.rb + 176: # is the intended way to override action dispatching. + 177: # + 178: # Notice that the first argument is the method to be dispatched + 179: # which is *not* necessarily the same as the action name. + 180: def process_action(method_name, *args) +=> 181: send_action(method_name, *args) + 182: end + 183: + 184: # Actually call the method associated with the action. Override + 185: # 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. -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. +You can also use `up [n]` 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 @@ -469,16 +489,15 @@ 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 stop _n_` stop thread _n_. -* `thread resume _n_` resumes thread _n_. -* `thread switch _n_` switches the current thread context to _n_. +* `thread`: shows the current thread. +* `thread list`: is used to list all threads and their statuses. The current +thread is marked with a plus (+) sign. +* `thread stop n`: stops 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 when you are debugging concurrent threads and need +to verify that there are no race conditions in your code. ### Inspecting Variables @@ -502,9 +521,9 @@ current context: 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] +[:@_action_has_layout, :@_routes, :@_request, :@_response, :@_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 @@ -514,14 +533,15 @@ 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 +=> 10 respond_to do |format| + 11 format.html # index.html.erb 12 format.json { render json: @articles } 13 end 14 end @@ -532,31 +552,40 @@ command later in this guide). And then ask again for the instance_variables: ``` -(byebug) instance_variables.include? "@articles" -true +(byebug) instance_variables +[:@_action_has_layout, :@_routes, :@_request, :@_response, :@_lookup_context, + :@_action_name, :@_response_body, :@marked_for_same_origin_verification, + :@_config, :@articles] ``` -Now `@articles` 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. +This will start an irb session within the context you invoked it. The `var` method is the most convenient way to show variables and their values. -Let's let `byebug` help us with it. +Let's have `byebug` help us with it. ``` (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 + + [v]ar <subcommand> + + Shows variables and its values + + + var all -- Shows local, global and instance variables of self. + var args -- Information about arguments of the current scope + var const -- Shows constants of an object. + var global -- Shows global variables. + var instance -- Shows instance variables of self or a specific object. + var local -- Shows local variables in current scope. + ``` 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. +example, to check that we have no local variables currently defined: ``` (byebug) var local @@ -570,16 +599,16 @@ You can also inspect for an object method this way: @_start_transaction_state = {} @aggregation_cache = {} @association_cache = {} -@attributes = {"id"=>nil, "created_at"=>nil, "updated_at"=>nil} -@attributes_cache = {} -@changed_attributes = nil -... +@attributes = #<ActiveRecord::AttributeSet:0x007fd0682a9b18 @attributes={"id"=>#<ActiveRecord::Attribute::FromDatabase:0x007fd0682a9a00 @name="id", @value_be... +@destroyed = false +@destroyed_by_association = nil +@marked_for_destruction = false +@new_record = true +@readonly = false +@transaction_state = 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. - -You can use also `display` to start watching variables. This is a good way of +You can also use `display` to start watching variables. This is a good way of tracking the values of a variable while the execution goes on. ``` @@ -587,56 +616,46 @@ tracking the values of a variable while the execution goes on. 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 +The variables inside the displayed 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 +available variables. But let's 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. - -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. - -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. +logical stopping point and return control to the debugger. `next` is similar to +`step`, but while `step` stops at the next line of code executed, doing just a +single step, `next` moves to the next line without descending inside methods. For example, consider the following situation: -```ruby +``` Started GET "/" for 127.0.0.1 at 2014-04-11 13:39:23 +0200 Processing by ArticlesController#index as HTML -[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 +[1, 6] in /PathToProject/app/models/article.rb + 1: class Article < ApplicationRecord + 2: def self.find_recent(limit = 10) + 3: byebug +=> 4: where('created_at > ?', 1.week.ago).limit(limit) + 5: end + 6: end (byebug) ``` -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. +If we use `next`, we won't go deep inside method calls. Instead, `byebug` will +go to the next line within the same context. In this case, it is the last line +of the current method, so `byebug` will return to the next line of the caller +method. ``` (byebug) next -Next went up a frame because previous frame finished - -[4, 13] in /PathTo/project/test_app/app/controllers/articles_controller.rb +[4, 13] in /PathToProject/app/controllers/articles_controller.rb 4: # GET /articles 5: # GET /articles.json 6: def index @@ -651,29 +670,29 @@ Next went up a frame because previous frame finished (byebug) ``` -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. +If we use `step` in the same situation, `byebug` will literally go to the next +Ruby instruction to be executed -- in this case, Active Support's `week` method. ``` (byebug) step -[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 - +[49, 58] in /PathToGems/activesupport-5.1.0/lib/active_support/core_ext/numeric/time.rb + 49: + 50: # Returns a Duration instance matching the number of weeks provided. + 51: # + 52: # 2.weeks # => 14 days + 53: def weeks +=> 54: ActiveSupport::Duration.weeks(self) + 55: end + 56: alias :week :weeks + 57: + 58: # Returns a Duration instance matching the number of fortnights provided. (byebug) ``` -This is one of the best ways to find bugs in your code, or perhaps in Ruby on -Rails. +This is one of the best ways to find bugs in your code. + +TIP: You can also use `step n` or `next n` to move forward `n` steps at once. ### Breakpoints @@ -683,19 +702,18 @@ 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: -* `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 n`: set breakpoint in line number _n_ in the current source file. +* `break file:n [if expression]`: set breakpoint in line number _n_ inside +file named _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. - +_expression_ works the same way as with file:n. For example, in the previous situation ``` -[4, 13] in /PathTo/project/app/controllers/articles_controller.rb +[4, 13] in /PathToProject/app/controllers/articles_controller.rb 4: # GET /articles 5: # GET /articles.json 6: def index @@ -708,20 +726,20 @@ For example, in the previous situation 13: end (byebug) break 11 -Created breakpoint 1 at /PathTo/project/app/controllers/articles_controller.rb:11 +Successfully created breakpoint with id 1 ``` -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` to list breakpoints. If you supply a number, it lists +that breakpoint. Otherwise it lists all breakpoints. ``` (byebug) info breakpoints Num Enb What -1 y at /PathTo/project/app/controllers/articles_controller.rb:11 +1 y at /PathToProject/app/controllers/articles_controller.rb:11 ``` -To delete breakpoints: use the command `delete _n_` to remove the breakpoint +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. @@ -733,10 +751,11 @@ No breakpoints. You can also enable or disable breakpoints: -* `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 +* `enable breakpoints [n [m [...]]]`: allows a specific breakpoint list or all +breakpoints 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. +* `disable breakpoints [n [m [...]]]`: make certain (or all) breakpoints have +no effect on your program. ### Catching Exceptions @@ -751,52 +770,72 @@ To list all active catchpoints use `catch`. 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. +* `continue [n]`: resumes program execution at the address where your script last +stopped; any breakpoints set at that address are bypassed. The optional argument +`n` allows you to specify a line number to set a one-time breakpoint which is +deleted when that breakpoint is reached. +* `finish [n]`: 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. +* `edit [file:n]`: edit file named _file_ using the editor specified by the +EDITOR environment variable. A specific line _n_ 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 to `q`). Or, type `q!` +to bypass the `Really quit? (y/n)` prompt and exit unconditionally. 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 -`byebug` has a few available options to tweak its behaviour: +`byebug` has a few available options to tweak its behavior: + +``` +(byebug) help set -* `set autoreload`: Reload source code when changed (defaults: true). -* `set autolist`: Execute `list` command on every breakpoint (defaults: true). -* `set listsize _n_`: Set number of source lines to list by default to _n_ -(defaults: 10) -* `set forcestep`: Make sure the `next` and `step` commands always move to a new -line. + set <setting> <value> -You can see the full list by using `help set`. Use `help set _subcommand_` to -learn about a particular `set` command. + Modifies byebug settings + + Boolean values take "on", "off", "true", "false", "1" or "0". If you + don't specify a value, the boolean setting will be enabled. Conversely, + you can use "set no<setting>" to disable them. + + You can see these environment settings with the "show" command. + + List of supported settings: + + autosave -- Automatically save command history record on exit + autolist -- Invoke list command on every stop + width -- Number of characters per line in byebug's output + autoirb -- Invoke IRB on every stop + basename -- <file>:<line> information after every stop uses short paths + linetrace -- Enable line execution tracing + autopry -- Invoke Pry on every stop + stack_on_error -- Display stack trace when `eval` raises an exception + fullpath -- Display full file names in backtraces + histfile -- File where cmd history is saved to. Default: ./.byebug_history + listsize -- Set number of source lines to list by default + post_mortem -- Enable/disable post-mortem mode + callstyle -- Set how you want method call parameters to be displayed + histsize -- Maximum number of commands that can be stored in byebug history + savefile -- File where settings are saved to. Default: ~/.byebug_save +``` 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 forcestep +set callstyle short set listsize 25 ``` @@ -809,7 +848,7 @@ controller. The console would be rendered next to your HTML content. ### Console -Inside any controller action or view, you can then invoke the console by +Inside any controller action or view, you can invoke the console by calling the `console` method. For example, in a controller: @@ -835,7 +874,7 @@ This will render a console inside your view. You don't need to care about the location of the `console` call; it won't be rendered on the spot of its invocation but next to your HTML content. -The console executes pure Ruby code. You can define and instantiate +The console executes pure Ruby code: You can define and instantiate custom classes, create new models and inspect variables. NOTE: Only one console can be rendered per request. Otherwise `web-console` @@ -860,7 +899,7 @@ to use it in production. Debugging Memory Leaks ---------------------- -A Ruby application (on Rails or not), can leak memory - either in the Ruby code +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 @@ -868,8 +907,8 @@ 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 an 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, if a C @@ -891,7 +930,7 @@ footnotes that give request information and link back to your source via TextMate. * [Query Trace](https://github.com/ruckus/active-record-query-trace/tree/master) Adds query origin tracing to your logs. -* [Query Reviewer](https://github.com/nesquena/query_reviewer) This rails plugin +* [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. @@ -903,19 +942,13 @@ 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. +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. +* [Pry](https://github.com/pry/pry) An IRB alternative and runtime developer console. References ---------- -* [ruby-debug Homepage](http://bashdb.sourceforge.net/ruby-debug/home-page.html) -* [debugger Homepage](https://github.com/cldwalker/debugger) * [byebug Homepage](https://github.com/deivid-rodriguez/byebug) * [web-console Homepage](https://github.com/rails/web-console) -* [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) diff --git a/guides/source/development_dependencies_install.md b/guides/source/development_dependencies_install.md index 989b29956c..50274d700b 100644 --- a/guides/source/development_dependencies_install.md +++ b/guides/source/development_dependencies_install.md @@ -9,7 +9,7 @@ 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 +* How the Active Record portion of the Rails test suite operates -------------------------------------------------------------------------------- @@ -21,25 +21,25 @@ The easiest and recommended way to get a development environment ready to hack i The Hard Way ------------ -In case you can't use the Rails development box, see section above, these are the steps to manually build a development box for Ruby on Rails core development. +In case you can't use the Rails development box, see the steps below to manually +build a development box for Ruby on Rails core development. ### Install Git -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: +Ruby on Rails uses Git for source code control. The [Git homepage](https://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.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.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. +* [Try Git course](https://try.github.io/) is an interactive course that will teach you the basics. +* The [official Documentation](https://git-scm.com/documentation) is pretty comprehensive and also contains some videos with the basics of Git. +* [Everyday Git](https://schacon.github.io/git/everyday.html) will teach you just enough about Git to get by. +* [GitHub](https://help.github.com/) offers links to a variety of Git resources. +* [Pro Git](https://git-scm.com/book) is an entire book about Git with a Creative Commons license. ### Clone the Ruby on Rails Repository Navigate to the folder where you want the Ruby on Rails source code (it will create its own `rails` subdirectory) and run: ```bash -$ git clone git://github.com/rails/rails.git +$ git clone https://github.com/rails/rails.git $ cd rails ``` @@ -47,7 +47,7 @@ $ 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 SQLite3 and its development files for the `sqlite3` gem. Mac OS X +Install first SQLite3 and its development files for the `sqlite3` gem. On macOS users are done with: ```bash @@ -60,10 +60,10 @@ In Ubuntu you're done with just: $ sudo apt-get install sqlite3 libsqlite3-dev ``` -And if you are on Fedora or CentOS, you're done with +If you are on Fedora or CentOS, you're done with ```bash -$ sudo yum install sqlite3 sqlite3-devel +$ sudo yum install libsqlite3x libsqlite3x-devel ``` If you are on Arch Linux, you will need to run: @@ -80,7 +80,7 @@ For FreeBSD users, you're done with: Or compile the `databases/sqlite3` port. -Get a recent version of [Bundler](http://bundler.io/) +Get a recent version of [Bundler](https://bundler.io/) ```bash $ gem install bundler @@ -97,7 +97,7 @@ This command will install all dependencies except the MySQL and PostgreSQL Ruby 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: +You can use [Homebrew](https://brew.sh/) to install memcached on macOS: ```bash $ brew install memcached @@ -163,9 +163,13 @@ $ cd actionpack $ bundle exec ruby -Itest path/to/test.rb -n test_name ``` +### Railties Setup + +Some Railties tests depend on a JavaScript runtime environment, such as having [Node.js](https://nodejs.org/) installed. + ### 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. +Active Record's test suite runs three times: once for SQLite3, once for MySQL, and once for PostgreSQL. We are going to see now how to set up the environment for them. WARNING: If you're working with Active Record code, you _must_ ensure that the tests pass for at least MySQL, PostgreSQL, and SQLite3. Subtle differences between the various adapters have been behind the rejection of many patches that looked OK when tested only against MySQL. @@ -178,7 +182,7 @@ The Active Record test suite requires a custom config file: `activerecord/test/c 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: +On macOS, you can run: ```bash $ brew install mysql @@ -187,10 +191,10 @@ $ brew install postgresql Follow the instructions given by Homebrew to start these. -In Ubuntu just run: +On Ubuntu, just run: ```bash -$ sudo apt-get install mysql-server libmysqlclient15-dev +$ sudo apt-get install mysql-server libmysqlclient-dev $ sudo apt-get install postgresql postgresql-client postgresql-contrib libpq-dev ``` @@ -213,7 +217,7 @@ FreeBSD users will have to run the following: ```bash # pkg install mysql56-client mysql56-server -# pkg install postgresql93-client postgresql93-server +# pkg install postgresql94-client postgresql94-server ``` Or install them through ports (they are located under the `databases` folder). @@ -257,35 +261,118 @@ with your development account, on Linux or BSD, you just have to run: $ sudo -u postgres createuser --superuser $USER ``` -and for OS X: +and for macOS: ```bash $ createuser --superuser $USER ``` -Then you need to create the test databases with +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 +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 +You can cleanup the databases using: ```bash $ cd activerecord $ 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: 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. + +### Action Cable Setup + +Action Cable uses Redis as its default subscriptions adapter ([read more](action_cable_overview.html#broadcasting)). Thus, in order to have Action Cable's tests passing you need to install and have Redis running. + +#### Install Redis From Source + +Redis' documentation discourage installations with package managers as those are usually outdated. Installing from source and bringing the server up is straight forward and well documented on [Redis' documentation](https://redis.io/download#installation). + +#### Install Redis From Package Manager + +On macOS, you can run: + +```bash +$ brew install redis +``` + +Follow the instructions given by Homebrew to start these. + +On Ubuntu, just run: + +```bash +$ sudo apt-get install redis-server +``` + +On Fedora or CentOS (requires EPEL enabled), just run: + +```bash +$ sudo yum install redis +``` + +If you are running Arch Linux, just run: + +```bash +$ sudo pacman -S redis +$ sudo systemctl start redis +``` + +FreeBSD users will have to run the following: + +```bash +# portmaster databases/redis +``` + +### Active Storage Setup + +When working on Active Storage, it is important to note that you need to +install its JavaScript dependencies while working on that section of the +codebase. In order to install these dependencies, it is necessary to +have Yarn, a Node.js package manager, available on your system. A +prerequisite for installing this package manager is that +[Node.js](https://nodejs.org) is installed. + + +On macOS, you can run: + +```bash +brew install yarn +``` + +On Ubuntu, you can run: + +```bash +curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add - +echo "deb https://dl.yarnpkg.com/debian/ stable main" | sudo tee /etc/apt/sources.list.d/yarn.list + +sudo apt-get update && sudo apt-get install yarn +``` + +On Fedora or CentOS, just run: + +```bash +sudo wget https://dl.yarnpkg.com/rpm/yarn.repo -O /etc/yum.repos.d/yarn.repo + +sudo yum install yarn +``` + +Finally, after installing Yarn, you will need to run the following +command inside of the `activestorage` directory to install the dependencies: + +```bash +yarn install +``` diff --git a/guides/source/documents.yaml b/guides/source/documents.yaml index 7ae3640937..5cddf79eeb 100644 --- a/guides/source/documents.yaml +++ b/guides/source/documents.yaml @@ -11,7 +11,7 @@ - name: Active Record Basics url: active_record_basics.html - description: This guide will get you started with models, persistence to database and the Active Record pattern and library. + description: This guide will get you started with models, persistence to database, and the Active Record pattern and library. - name: Active Record Migrations url: active_record_migrations.html @@ -19,7 +19,7 @@ - name: Active Record Validations url: active_record_validations.html - description: This guide covers how you can use Active Record validations + description: This guide covers how you can use Active Record validations. - name: Active Record Callbacks url: active_record_callbacks.html @@ -72,9 +72,9 @@ url: active_support_core_extensions.html description: This guide documents the Ruby core extensions defined in Active Support. - - name: Rails Internationalization API + name: Rails Internationalization (I18n) API url: i18n.html - description: This guide covers how to add internationalization to your applications. Your application will be able to translate content to different languages, change pluralization rules, use correct date formats for each country and so on. + description: This guide covers how to add internationalization to your applications. Your application will be able to translate content to different languages, change pluralization rules, use correct date formats for each country, and so on. - name: Action Mailer Basics url: action_mailer_basics.html @@ -82,12 +82,15 @@ - 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. + description: This guide provides you with all you need to get started creating, enqueuing, and executing background jobs. + - + name: Active Storage Overview + url: active_storage_overview.html + description: This guide covers how to attach files to your Active Record models. - name: Testing Rails Applications - work_in_progress: true 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. + description: This is a rather comprehensive guide to the various testing facilities in Rails. It covers everything from 'What is a test?' to Integration Testing. Enjoy. - name: Securing Rails Applications url: security.html @@ -101,11 +104,11 @@ url: configuring.html description: This guide covers the basic configuration settings for a Rails application. - - name: Rails Command Line Tools and Rake Tasks + name: The Rails Command Line url: command_line.html - description: This guide covers the command line tools and rake tasks provided by Rails. + description: This guide covers the command line tools provided by Rails. - - name: Asset Pipeline + name: The Asset Pipeline url: asset_pipeline.html description: This guide documents the asset pipeline. - @@ -116,21 +119,28 @@ 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 4 + description: This guide explains the internals of the Rails initialization process. - name: Autoloading and Reloading Constants url: autoloading_and_reloading_constants.html description: This guide documents how autoloading and reloading constants work. - + name: "Caching with Rails: An Overview" + url: caching_with_rails.html + description: This guide is an introduction to speeding up your Rails application with caching. + - 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: Using Rails for API-only Applications + url: api_app.html + description: This guide explains how to effectively use Rails to develop a JSON API application. + - + name: Action Cable Overview + url: action_cable_overview.html + description: This guide explains how Action Cable works, and how to use WebSockets to create real-time features. - name: Extending Rails @@ -145,7 +155,7 @@ url: rails_on_rack.html description: This guide covers Rails integration with Rack and interfacing with other Rack components. - - name: Creating and Customizing Rails Generators + name: Creating and Customizing Rails Generators & Templates 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). - @@ -153,6 +163,11 @@ url: engines.html description: This guide explains how to write a mountable engine. work_in_progress: true + - + name: Threading and Code Execution in Rails + url: threading_and_code_execution.html + description: This guide describes the considerations needed and tools available when working directly with concurrency in a Rails application. + work_in_progress: true - name: Contributing to Ruby on Rails documents: @@ -172,7 +187,7 @@ name: Maintenance Policy documents: - - name: Maintenance Policy + name: Maintenance Policy for Ruby on Rails url: maintenance_policy.html description: What versions of Ruby on Rails are currently supported, and when to expect new versions. - @@ -183,6 +198,18 @@ url: upgrading_ruby_on_rails.html description: This guide helps in upgrading applications to latest Ruby on Rails versions. - + name: Ruby on Rails 5.2 Release Notes + url: 5_2_release_notes.html + description: Release notes for Rails 5.2. + - + name: Ruby on Rails 5.1 Release Notes + url: 5_1_release_notes.html + description: Release notes for Rails 5.1. + - + name: Ruby on Rails 5.0 Release Notes + url: 5_0_release_notes.html + description: Release notes for Rails 5.0. + - name: Ruby on Rails 4.2 Release Notes url: 4_2_release_notes.html description: Release notes for Rails 4.2. diff --git a/guides/source/engines.md b/guides/source/engines.md index 84017d5e13..8d81296fa5 100644 --- a/guides/source/engines.md +++ b/guides/source/engines.md @@ -11,9 +11,10 @@ After reading this guide, you will know: * What makes an engine. * How to generate an engine. -* Building features for the engine. -* Hooking the engine into an application. -* Overriding engine functionality in the application. +* How to build features for the engine. +* How to hook the engine into an application. +* How to override engine functionality in the application. +* Avoid loading Rails frameworks with Load and Configuration Hooks -------------------------------------------------------------------------------- @@ -25,7 +26,7 @@ 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, +Therefore, engines and applications can be thought of as almost the same thing, just with subtle differences, as you'll see throughout this guide. Engines and applications also share a common structure. @@ -46,7 +47,7 @@ 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 use an engine that also 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. @@ -59,10 +60,10 @@ 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 +[Thredded](https://github.com/thredded/thredded), 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. +[Refinery CMS](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 @@ -150,7 +151,7 @@ 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" +gem 'blorgh', path: 'engines/blorgh' ``` Don't forget to run `bundle install` as usual. By specifying it as a gem within @@ -184,7 +185,7 @@ 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 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 @@ -239,6 +240,27 @@ 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. +NOTE: Because of the way that Ruby does constant lookup you may run into a situation +where your engine controller is inheriting from the main application controller and +not your engine's application controller. Ruby is able to resolve the `ApplicationController` constant, and therefore the autoloading mechanism is not triggered. See the section [When Constants Aren't Missed](autoloading_and_reloading_constants.html#when-constants-aren-t-missed) of the [Autoloading and Reloading Constants](autoloading_and_reloading_constants.html) guide for further details. The best way to prevent this from +happening is to use `require_dependency` to ensure that the engine's application +controller is loaded. For example: + +``` ruby +# app/controllers/blorgh/articles_controller.rb: +require_dependency "blorgh/application_controller" + +module Blorgh + class ArticlesController < ApplicationController + ... + end +end +``` + +WARNING: Don't use `require` because it will break the automatic reloading of classes +in the development environment - using `require_dependency` ensures that classes are +loaded and unloaded in the correct manner. + 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 @@ -324,6 +346,9 @@ invoke test_unit create test/controllers/blorgh/articles_controller_test.rb invoke helper create app/helpers/blorgh/articles_helper.rb +invoke test_unit +create test/application_system_test_case.rb +create test/system/articles_test.rb invoke assets invoke js create app/assets/javascripts/blorgh/articles.js @@ -368,7 +393,7 @@ 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`). +(`app/helpers/blorgh/articles_helper.rb`). Everything this generator has created is neatly namespaced. The controller's class is defined within the `Blorgh` module: @@ -381,8 +406,8 @@ module Blorgh end ``` -NOTE: The `ApplicationController` class being inherited from here is the -`Blorgh::ApplicationController`, not an application's `ApplicationController`. +NOTE: The `ArticlesController` class inherits from +`Blorgh::ApplicationController`, not the application's `ApplicationController`. The helper inside `app/helpers/blorgh/articles_helper.rb` is also namespaced: @@ -402,16 +427,7 @@ Finally, the assets for this resource are generated in two files: `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 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 +You can see what the engine has so far by running `bin/rails 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 @@ -449,7 +465,7 @@ model, a comment controller and then modify the articles scaffold to display comments and allow people to create new ones. 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 +`Comment` model, with the related table having two columns: an `article_id` integer and `text` text column. ```bash @@ -473,7 +489,7 @@ called `Blorgh::Comment`. Now run the migration to create our blorgh_comments table: ```bash -$ rake db:migrate +$ bin/rails db:migrate ``` To show the comments on an article, edit `app/views/blorgh/articles/show.html.erb` and @@ -496,7 +512,7 @@ Turning the model into this: ```ruby module Blorgh - class Article < ActiveRecord::Base + class Article < ApplicationRecord has_many :comments end end @@ -521,12 +537,12 @@ directory at `app/views/blorgh/comments` and in it a new file called ```html+erb <h3>New comment</h3> -<%= form_for [@article, @article.comments.build] do |f| %> +<%= form_with(model: [@article, @article.comments.build], local: true) do |form| %> <p> - <%= f.label :text %><br> - <%= f.text_area :text %> + <%= form.label :text %><br> + <%= form.text_area :text %> </p> - <%= f.submit %> + <%= form.submit %> <% end %> ``` @@ -591,7 +607,7 @@ 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], +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" @@ -600,7 +616,7 @@ Missing partial blorgh/comments/comment with {:handlers=>[:erb, :builder], 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 +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. @@ -637,7 +653,7 @@ there isn't an application handy to test this out in, generate one using the $ rails new unicorn ``` -Usually, specifying the engine inside the Gemfile would be done by specifying it +Usually, specifying the engine inside the `Gemfile` would be done by specifying it as a normal, everyday gem. ```ruby @@ -648,7 +664,7 @@ 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" +gem 'blorgh', path: 'engines/blorgh' ``` Then run `bundle` to install the gem. @@ -679,17 +695,17 @@ pre-defined path which may be customizable. 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: +application run the following command from the `test/dummy` directory of your Rails engine: ```bash -$ rake blorgh:install:migrations +$ bin/rails blorgh:install:migrations ``` If you have multiple engines that need migrations copied over, use `railties:install:migrations` instead: ```bash -$ rake railties:install:migrations +$ bin/rails railties:install:migrations ``` This command, when run for the first time, will copy over all the migrations @@ -698,8 +714,8 @@ 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_articles.rb from blorgh -Copied migration [timestamp_2]_create_blorgh_comments.rb from blorgh +Copied migration [timestamp_1]_create_blorgh_articles.blorgh.rb from blorgh +Copied migration [timestamp_2]_create_blorgh_comments.blorgh.rb from blorgh ``` The first timestamp (`[timestamp_1]`) will be the current time, and the second @@ -707,7 +723,7 @@ 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 +To run these migrations within the context of the application, simply run `bin/rails 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 @@ -718,14 +734,14 @@ If you would like to run migrations only from one engine, you can do it by specifying `SCOPE`: ```bash -rake db:migrate SCOPE=blorgh +bin/rails db:migrate SCOPE=blorgh ``` 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 +bin/rails db:migrate SCOPE=blorgh VERSION=0 ``` ### Using a Class Provided by the Application @@ -752,7 +768,7 @@ application: rails g model user name:string ``` -The `rake db:migrate` command needs to be run here to ensure that our +The `bin/rails 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 articles form will have a new text field called @@ -767,8 +783,8 @@ added above the `title` field with this code: ```html+erb <div class="field"> - <%= f.label :author_name %><br> - <%= f.text_field :author_name %> + <%= form.label :author_name %><br> + <%= form.text_field :author_name %> </div> ``` @@ -787,7 +803,7 @@ 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 +association for the author and the `before_validation` call into `app/models/blorgh/article.rb`. The `author` association will be hard-coded to the `User` class for the time being. @@ -795,7 +811,7 @@ association for the author and the `before_save` call into attr_accessor :author_name belongs_to :author, class_name: "User" -before_save :set_author +before_validation :set_author private def set_author @@ -824,24 +840,22 @@ 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 +$ bin/rails blorgh:install:migrations ``` 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_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 +NOTE Migration [timestamp]_create_blorgh_articles.blorgh.rb from blorgh has been skipped. Migration with the same name already exists. +NOTE Migration [timestamp]_create_blorgh_comments.blorgh.rb from blorgh has been skipped. Migration with the same name already exists. +Copied migration [timestamp]_add_author_id_to_blorgh_articles.blorgh.rb from blorgh ``` Run the migration using: ```bash -$ rake db:migrate +$ bin/rails db:migrate ``` Now with all the pieces in place, an action will take place that will associate @@ -854,28 +868,10 @@ above the "Title" output inside `app/views/blorgh/articles/show.html.erb`: ```html+erb <p> <b>Author:</b> - <%= @article.author %> + <%= @article.author.name %> </p> ``` -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. 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 - name -end -``` - -Now instead of the ugly Ruby object output, the author's name will be displayed. - #### Using a Controller Provided by the Application Because Rails controllers generally share code for things like authentication @@ -925,7 +921,7 @@ engine: mattr_accessor :author_class ``` -This method works like its brothers, `attr_accessor` and `cattr_accessor`, but +This method works like its siblings, `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`. @@ -986,7 +982,7 @@ 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. This could lead to -problems if the table wasn't already existing. Therefore, a `String` should be +problems if the table didn't already exist. 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 article. You will see that it works exactly in the @@ -1041,9 +1037,11 @@ typical `GET` to a controller in a controller's functional test like this: ```ruby module Blorgh - class FooControllerTest < ActionController::TestCase + class FooControllerTest < ActionDispatch::IntegrationTest + include Engine.routes.url_helpers + def test_index - get :index + get foos_url ... end end @@ -1057,13 +1055,15 @@ in your setup code: ```ruby module Blorgh - class FooControllerTest < ActionController::TestCase + class FooControllerTest < ActionDispatch::IntegrationTest + include Engine.routes.url_helpers + setup do @routes = Engine.routes end def test_index - get :index + get foos_url ... end end @@ -1137,7 +1137,7 @@ end ```ruby # Blorgh/app/models/article.rb -class Article < ActiveRecord::Base +class Article < ApplicationRecord has_many :comments end ``` @@ -1158,7 +1158,7 @@ end ```ruby # Blorgh/app/models/article.rb -class Article < ActiveRecord::Base +class Article < ApplicationRecord has_many :comments def summary "#{title}" @@ -1179,7 +1179,7 @@ classes at run time allowing you to significantly modularize your code. ```ruby # MyApp/app/models/blorgh/article.rb -class Blorgh::Article < ActiveRecord::Base +class Blorgh::Article < ApplicationRecord include Blorgh::Concerns::Models::Article def time_since_created @@ -1195,13 +1195,13 @@ end ```ruby # Blorgh/app/models/article.rb -class Article < ActiveRecord::Base +class Article < ApplicationRecord include Blorgh::Concerns::Models::Article end ``` ```ruby -# Blorgh/lib/concerns/models/article +# Blorgh/lib/concerns/models/article.rb module Blorgh::Concerns::Models::Article extend ActiveSupport::Concern @@ -1213,7 +1213,7 @@ module Blorgh::Concerns::Models::Article attr_accessor :author_name belongs_to :author, class_name: "User" - before_save :set_author + before_validation :set_author private def set_author @@ -1322,7 +1322,7 @@ engine. 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. +look up assets in the engine's `app/assets` and `lib/assets` directories. 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 @@ -1361,14 +1361,14 @@ 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. +explicitly define these assets for precompilation. This tells Sprockets to add +your engine assets when `bin/rails assets:precompile` is triggered. You can define assets for precompilation in `engine.rb`: ```ruby initializer "blorgh.assets.precompile" do |app| - app.config.assets.precompile += %w(admin.css admin.js) + app.config.assets.precompile += %w( admin.js admin.css ) end ``` @@ -1414,3 +1414,115 @@ module MyEngine end end ``` + +Active Support On Load Hooks +---------------------------- + +Active Support is the Ruby on Rails component responsible for providing Ruby language extensions, utilities, and other transversal utilities. + +Rails code can often be referenced on load of an application. Rails is responsible for the load order of these frameworks, so when you load frameworks, such as `ActiveRecord::Base`, prematurely you are violating an implicit contract your application has with Rails. Moreover, by loading code such as `ActiveRecord::Base` on boot of your application you are loading entire frameworks which may slow down your boot time and could cause conflicts with load order and boot of your application. + +On Load hooks are the API that allow you to hook into this initialization process without violating the load contract with Rails. This will also mitigate boot performance degradation and avoid conflicts. + +## What are `on_load` hooks? + +Since Ruby is a dynamic language, some code will cause different Rails frameworks to load. Take this snippet for instance: + +```ruby +ActiveRecord::Base.include(MyActiveRecordHelper) +``` + +This snippet means that when this file is loaded, it will encounter `ActiveRecord::Base`. This encounter causes Ruby to look for the definition of that constant and will require it. This causes the entire Active Record framework to be loaded on boot. + +`ActiveSupport.on_load` is a mechanism that can be used to defer the loading of code until it is actually needed. The snippet above can be changed to: + +```ruby +ActiveSupport.on_load(:active_record) { include MyActiveRecordHelper } +``` + +This new snippet will only include `MyActiveRecordHelper` when `ActiveRecord::Base` is loaded. + +## How does it work? + +In the Rails framework these hooks are called when a specific library is loaded. For example, when `ActionController::Base` is loaded, the `:action_controller_base` hook is called. This means that all `ActiveSupport.on_load` calls with `:action_controller_base` hooks will be called in the context of `ActionController::Base` (that means `self` will be an `ActionController::Base`). + +## Modifying code to use `on_load` hooks + +Modifying code is generally straightforward. If you have a line of code that refers to a Rails framework such as `ActiveRecord::Base` you can wrap that code in an `on_load` hook. + +### Example 1 + +```ruby +ActiveRecord::Base.include(MyActiveRecordHelper) +``` + +becomes + +```ruby +ActiveSupport.on_load(:active_record) { include MyActiveRecordHelper } # self refers to ActiveRecord::Base here, so we can simply #include +``` + +### Example 2 + +```ruby +ActionController::Base.prepend(MyActionControllerHelper) +``` + +becomes + +```ruby +ActiveSupport.on_load(:action_controller_base) { prepend MyActionControllerHelper } # self refers to ActionController::Base here, so we can simply #prepend +``` + +### Example 3 + +```ruby +ActiveRecord::Base.include_root_in_json = true +``` + +becomes + +```ruby +ActiveSupport.on_load(:active_record) { self.include_root_in_json = true } # self refers to ActiveRecord::Base here +``` + +## Available Hooks + +These are the hooks you can use in your own code. + +To hook into the initialization process of one of the following classes use the available hook. + +| Class | Available Hooks | +| --------------------------------- | ------------------------------------ | +| `ActionCable` | `action_cable` | +| `ActionController::API` | `action_controller_api` | +| `ActionController::API` | `action_controller` | +| `ActionController::Base` | `action_controller_base` | +| `ActionController::Base` | `action_controller` | +| `ActionController::TestCase` | `action_controller_test_case` | +| `ActionDispatch::IntegrationTest` | `action_dispatch_integration_test` | +| `ActionDispatch::SystemTestCase` | `action_dispatch_system_test_case` | +| `ActionMailer::Base` | `action_mailer` | +| `ActionMailer::TestCase` | `action_mailer_test_case` | +| `ActionView::Base` | `action_view` | +| `ActionView::TestCase` | `action_view_test_case` | +| `ActiveJob::Base` | `active_job` | +| `ActiveJob::TestCase` | `active_job_test_case` | +| `ActiveRecord::Base` | `active_record` | +| `ActiveSupport::TestCase` | `active_support_test_case` | +| `i18n` | `i18n` | + +## Configuration hooks + +These are the available configuration hooks. They do not hook into any particular framework, but instead they run in context of the entire application. + +| Hook | Use Case | +| ---------------------- | ---------------------------------------------------------------------------------- | +| `before_configuration` | First configurable block to run. Called before any initializers are run. | +| `before_initialize` | Second configurable block to run. Called before frameworks initialize. | +| `before_eager_load` | Third configurable block to run. Does not run if `config.eager_load` set to false. | +| `after_initialize` | Last configurable block to run. Called after frameworks initialize. | + +### Example + +`config.before_configuration { puts 'I am called before any initializers' }` diff --git a/guides/source/form_helpers.md b/guides/source/form_helpers.md index 853227e2a1..53c567727f 100644 --- a/guides/source/form_helpers.md +++ b/guides/source/form_helpers.md @@ -1,7 +1,7 @@ **DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON http://guides.rubyonrails.org.** -Form Helpers -============ +Action View 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 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. @@ -40,7 +40,9 @@ When called without arguments like this, it creates a `<form>` tag which, when s </form> ``` -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). +You'll notice that the HTML contains an `input` element with type `hidden`. This `input` is important, because the form cannot be successfully submitted without it. The hidden input element with the name `utf8` enforces browsers to properly respect your form's character encoding and is generated for all forms whether their action is "GET" or "POST". + +The second input element with the 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 @@ -103,9 +105,9 @@ 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 +data, and will make its way to the `params` 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). @@ -162,7 +164,7 @@ make it easier for users to click the inputs. 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, +color fields, datetime-local fields, month fields, week fields, URL fields, email fields, number fields and range fields: ```erb @@ -172,7 +174,6 @@ URL fields, email fields, number fields and range fields: <%= search_field(:user, :name) %> <%= telephone_field(:user, :phone) %> <%= date_field(:user, :born_on) %> -<%= datetime_field(:user, :meeting_time) %> <%= datetime_local_field(:user, :graduation_day) %> <%= month_field(:user, :birthday_month) %> <%= week_field(:user, :birthday_week) %> @@ -193,7 +194,6 @@ Output: <input id="user_name" name="user[name]" type="search" /> <input id="user_phone" name="user[phone]" type="tel" /> <input id="user_born_on" name="user[born_on]" type="date" /> -<input id="user_meeting_time" name="user[meeting_time]" type="datetime" /> <input id="user_graduation_day" name="user[graduation_day]" type="datetime-local" /> <input id="user_birthday_month" name="user[birthday_month]" type="month" /> <input id="user_birthday_week" name="user[birthday_week]" type="week" /> @@ -211,9 +211,8 @@ 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 +There is definitely [no shortage of solutions for this](https://github.com/Modernizr/Modernizr/wiki/HTML5-Cross-Browser-Polyfills), although a popular tool at the moment is +[Modernizr](https://modernizr.com/), which provides 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). @@ -275,10 +274,12 @@ There are a few things to note here: The resulting HTML is: ```html -<form accept-charset="UTF-8" action="/articles" method="post" class="nifty_form"> - <input id="article_title" name="article[title]" type="text" /> - <textarea id="article_body" name="article[body]" cols="60" rows="12"></textarea> - <input name="commit" type="submit" value="Create" /> +<form class="nifty_form" id="new_article" action="/articles" accept-charset="UTF-8" method="post"> + <input name="utf8" type="hidden" value="✓" /> + <input type="hidden" name="authenticity_token" value="NRkFyRWxdYNfUg7vYxLOp2SLf93lvnl+QwDWorR42Dp6yZXPhHEb6arhDOIWcqGit8jfnrPwL781/xlrzj63TA==" /> + <input type="text" name="article[title]" id="article_title" /> + <textarea name="article[body]" id="article_body" cols="60" rows="12"></textarea> + <input type="submit" name="commit" value="Create" data-disable-with="Create" /> </form> ``` @@ -291,8 +292,8 @@ You can create a similar binding without actually creating `<form>` tags with th ```erb <%= form_for @person, url: {action: "create"} do |person_form| %> <%= person_form.text_field :name %> - <%= fields_for @person.contact_detail do |contact_details_form| %> - <%= contact_details_form.text_field :phone_number %> + <%= fields_for @person.contact_detail do |contact_detail_form| %> + <%= contact_detail_form.text_field :phone_number %> <% end %> <% end %> ``` @@ -300,9 +301,11 @@ You can create a similar binding without actually creating `<form>` tags with th which produces the following output: ```html -<form accept-charset="UTF-8" action="/people" class="new_person" id="new_person" method="post"> - <input id="person_name" name="person[name]" type="text" /> - <input id="contact_detail_phone_number" name="contact_detail[phone_number]" type="text" /> +<form class="new_person" id="new_person" action="/people" accept-charset="UTF-8" method="post"> + <input name="utf8" type="hidden" value="✓" /> + <input type="hidden" name="authenticity_token" value="bL13x72pldyDD8bgtkjKQakJCpd4A8JdXGbfksxBDHdf1uC0kCMqe2tvVdUYfidJt0fj3ihC4NxiVHv8GVYxJA==" /> + <input type="text" name="person[name]" id="person_name" /> + <input type="text" name="contact_detail[phone_number]" id="contact_detail_phone_number" /> </form> ``` @@ -316,7 +319,7 @@ The Article model is directly available to users of the application, so - follow resources :articles ``` -TIP: Declaring a resource has a number of side-affects. See [Rails Routing From the Outside In](routing.html#resource-routing-the-rails-default) for more information on setting up and using resources. +TIP: Declaring a resource has a number of side effects. See [Rails Routing From the Outside In](routing.html#resource-routing-the-rails-default) for more information on setting up and using resources. When dealing with RESTful resources, calls to `form_for` can get significantly easier if you rely on **record identification**. In short, you can just pass the model instance and have Rails figure out model name and the rest: @@ -377,7 +380,7 @@ output: </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). +When parsing POSTed data, Rails will take into account the special `_method` parameter and act as if the HTTP method was the one specified inside it ("PATCH" in this example). Making Select Boxes with Ease ----------------------------- @@ -439,9 +442,7 @@ 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. - -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. +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: @@ -534,7 +535,7 @@ To leverage time zone support in Rails, you have to ask your users what time zon <%= time_zone_select(:person, :time_zone) %> ``` -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. +There is also `time_zone_options_for_select` helper for a more manual (therefore more customizable) way of doing this. Read the [API documentation](http://api.rubyonrails.org/classes/ActionView/Helpers/FormOptionsHelper.html#method-i-time_zone_options_for_select) 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/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). @@ -656,7 +657,7 @@ NOTE: If the user has not selected a file the corresponding parameter will be an ### Dealing with Ajax -Unlike other forms making an asynchronous file upload form is not as simple as providing `form_for` with `remote: true`. With an Ajax form the serialization is done by JavaScript running inside the browser and since JavaScript cannot read files from your hard drive the file cannot be uploaded. The most common workaround is to use an invisible iframe that serves as the target for the form submission. +Unlike other forms, making an asynchronous file upload form is not as simple as providing `form_for` with `remote: true`. With an Ajax form the serialization is done by JavaScript running inside the browser and since JavaScript cannot read files from your hard drive the file cannot be uploaded. The most common workaround is to use an invisible iframe that serves as the target for the form submission. Customizing Form Builders ------------------------- @@ -712,13 +713,6 @@ action for a Person model, `params[:person]` would usually be a hash of all the 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 Rack's parameter parser. For example, - -```ruby -Rack::Utils.parse_query "name=fred&phone=0123456789" -# => {"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: @@ -886,12 +880,12 @@ Many apps grow beyond simple forms editing a single object. For example, when cr Active Record provides model level support via the `accepts_nested_attributes_for` method: ```ruby -class Person < ActiveRecord::Base - has_many :addresses +class Person < ApplicationRecord + has_many :addresses, inverse_of: :person accepts_nested_attributes_for :addresses end -class Address < ActiveRecord::Base +class Address < ApplicationRecord belongs_to :person end ``` @@ -926,7 +920,7 @@ When an association accepts nested attributes `fields_for` renders its block onc ```ruby def new @person = Person.new - 2.times { @person.addresses.build} + 2.times { @person.addresses.build } end ``` @@ -979,7 +973,7 @@ private You can allow users to delete associated objects by passing `allow_destroy: true` to `accepts_nested_attributes_for` ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord has_many :addresses accepts_nested_attributes_for :addresses, allow_destroy: true end @@ -1020,7 +1014,7 @@ end 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. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord has_many :addresses accepts_nested_attributes_for :addresses, reject_if: lambda {|attributes| attributes['kind'].blank?} end diff --git a/guides/source/generators.md b/guides/source/generators.md index 14f451cbc9..b7b8262e4a 100644 --- a/guides/source/generators.md +++ b/guides/source/generators.md @@ -90,13 +90,15 @@ $ bin/rails generate generator initializer create lib/generators/initializer/initializer_generator.rb create lib/generators/initializer/USAGE create lib/generators/initializer/templates + invoke test_unit + create test/lib/generators/initializer_generator_test.rb ``` This is the generator just created: ```ruby class InitializerGenerator < Rails::Generators::NamedBase - source_root File.expand_path("../templates", __FILE__) + source_root File.expand_path('templates', __dir__) end ``` @@ -122,7 +124,7 @@ And now let's change the generator to copy this template when invoked: ```ruby class InitializerGenerator < Rails::Generators::NamedBase - source_root File.expand_path("../templates", __FILE__) + source_root File.expand_path('templates', __dir__) def copy_initializer_file copy_file "initializer.rb", "config/initializers/#{file_name}.rb" @@ -197,6 +199,9 @@ $ bin/rails generate scaffold User name:string invoke jbuilder create app/views/users/index.json.jbuilder create app/views/users/show.json.jbuilder + invoke test_unit + create test/application_system_test_case.rb + create test/system/users_test.rb invoke assets invoke coffee create app/assets/javascripts/users.coffee @@ -208,7 +213,15 @@ $ bin/rails generate scaffold User name:string 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 stylesheet, JavaScript and test fixture files for scaffolds. We can achieve that by changing our configuration to the following: +If we want to avoid generating the default `app/assets/stylesheets/scaffolds.scss` file when scaffolding a new resource we can disable `scaffold_stylesheet`: + +```ruby + config.generators do |g| + g.scaffold_stylesheet false + end +``` + +The next customization on the workflow will be to stop generating stylesheet, JavaScript and test fixture files for scaffolds altogether. We can achieve that by changing our configuration to the following: ```ruby config.generators do |g| @@ -230,6 +243,8 @@ $ bin/rails generate generator 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 + invoke test_unit + create test/lib/generators/rails/my_helper_generator_test.rb ``` After that, we can delete both the `templates` directory and the `source_root` @@ -407,6 +422,9 @@ $ bin/rails generate scaffold Comment body:text invoke jbuilder create app/views/comments/index.json.jbuilder create app/views/comments/show.json.jbuilder + invoke test_unit + create test/application_system_test_case.rb + create test/system/comments_test.rb invoke assets invoke coffee create app/assets/javascripts/comments.coffee @@ -418,7 +436,7 @@ Fallbacks allow your generators to have a single responsibility, increasing code Application Templates --------------------- -Now that you've seen how generators can be used _inside_ an application, did you know they can also be used to _generate_ applications too? This kind of generator is referred as a "template". This is a brief overview of the Templates API. For detailed documentation see the [Rails Application Templates guide](rails_application_templates.html). +Now that you've seen how generators can be used _inside_ an application, did you know they can also be used to _generate_ applications too? This kind of generator is referred to as a "template". This is a brief overview of the Templates API. For detailed documentation see the [Rails Application Templates guide](rails_application_templates.html). ```ruby gem "rspec-rails", group: "test" @@ -451,6 +469,26 @@ $ 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. +Adding Command Line Arguments +----------------------------- +Rails generators can be easily modified to accept custom command line arguments. This functionality comes from [Thor](http://www.rubydoc.info/github/erikhuda/thor/master/Thor/Base/ClassMethods#class_option-instance_method): + +``` +class_option :scope, type: :string, default: 'read_products' +``` + +Now our generator can be invoked as follows: + +```bash +rails generate initializer --scope write_products +``` + +The command line arguments are accessed through the `options` method inside the generator class. e.g: + +```ruby +@scope = options['scope'] +``` + Generator methods ----------------- @@ -476,13 +514,13 @@ Available options are: Any additional options passed to this method are put on the end of the line: ```ruby -gem "devise", git: "git://github.com/plataformatec/devise", branch: "master" +gem "devise", git: "https://github.com/plataformatec/devise.git", branch: "master" ``` The above code will put the following line into `Gemfile`: ```ruby -gem "devise", git: "git://github.com/plataformatec/devise", branch: "master" +gem "devise", git: "https://github.com/plataformatec/devise.git", branch: "master" ``` ### `gem_group` @@ -503,6 +541,14 @@ Adds a specified source to `Gemfile`: add_source "http://gems.github.com" ``` +This method also takes a block: + +```ruby +add_source "http://gems.github.com" do + gem "rspec-rails" +end +``` + ### `inject_into_file` Injects a block of code into a defined position in your file. @@ -591,7 +637,7 @@ This method also takes a block: ```ruby lib "super_special.rb" do - puts "Super special!" + "puts 'Super special!'" end ``` @@ -600,7 +646,7 @@ end Creates a Rake file in the `lib/tasks` directory of the application. ```ruby -rakefile "test.rake", "hello there" +rakefile "test.rake", 'task(:hello) { puts "Hello, there" }' ``` This method also takes a block: @@ -653,14 +699,6 @@ Available options are: * `:env` - Specifies the environment in which to run this rake task. * `:sudo` - Whether or not to run this task using `sudo`. Defaults to `false`. -### `capify!` - -Runs the `capify` command from Capistrano at the root of the application which generates Capistrano configuration. - -```ruby -capify! -``` - ### `route` Adds text to the `config/routes.rb` file: diff --git a/guides/source/getting_started.md b/guides/source/getting_started.md index 922ec3922e..b007baea87 100644 --- a/guides/source/getting_started.md +++ b/guides/source/getting_started.md @@ -20,13 +20,7 @@ Guide Assumptions This guide is designed for beginners who want to get started with a Rails 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](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). +with Rails. 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 @@ -34,7 +28,7 @@ curve diving straight into Rails. There are several curated lists of online reso 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) +* [List of Free Programming Books](https://github.com/vhf/free-programming-books/blob/master/free-programming-books.md#ruby) 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 @@ -43,14 +37,14 @@ development with Rails. What is Rails? -------------- -Rails is a web application development framework written in the Ruby language. +Rails is a web application development framework written in the Ruby programming language. It is designed to make programming web applications easier by making assumptions about what every developer needs to get started. It allows you to write less 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 the "best" +Rails is opinionated software. It makes the assumption that there is a "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 @@ -65,14 +59,13 @@ The Rails philosophy includes two major guiding principles: 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. + require that you specify 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. +The best way to read this guide is to follow it step by step. All steps are +essential to run this example application and no additional code or steps are +needed. 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, @@ -84,22 +77,32 @@ your prompt will look something like `c:\source_code>` ### Installing Rails -Open up a command line prompt. On Mac OS X open Terminal.app, on Windows choose +Before you install Rails, you should check to make sure that your system has the +proper prerequisites installed. These include Ruby and SQLite3. + +Open up a command line prompt. On macOS open Terminal.app, on Windows choose "Run" from your Start menu and type 'cmd.exe'. Any commands prefaced with a dollar sign `$` should be run in the command line. Verify that you have a current version of Ruby installed: +```bash +$ ruby -v +ruby 2.3.1p112 +``` + +Rails requires Ruby version 2.2.2 or later. If the version number returned is +less than that number, you'll need to install a fresh copy of Ruby. + 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). +while macOS 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 2.0.0p353 -``` +If you are working on Windows, you should also install the +[Ruby Installer Development Kit](http://rubyinstaller.org/downloads/). +You will also need an installation of the SQLite3 database. 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 @@ -125,7 +128,7 @@ run the following: $ rails --version ``` -If it says something like "Rails 5.0.0", you are ready to continue. +If it says something like "Rails 5.1.1", you are ready to continue. ### Creating the Blog Application @@ -146,6 +149,10 @@ 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`. +NOTE: If you're using Windows Subsystem for Linux then there are currently some +limitations on file system notifications that mean you should disable the `spring` +and `listen` gems which you can do by running `rails new blog --skip-spring --skip-listen`. + TIP: You can see all of the command line options that the Rails application builder accepts by running `rails new -h`. @@ -162,20 +169,23 @@ 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.| -|bin/|Contains the rails script that starts your app and can contain other scripts you use to setup, deploy or run your application.| +|app/|Contains the controllers, models, views, helpers, mailers, channels, jobs and assets for your application. You'll focus on this folder for the remainder of this guide.| +|bin/|Contains the rails script that starts your app and can contain other scripts you use to setup, update, 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.| +|config.ru|Rack configuration for Rack based servers used to start the application. For more information about Rack, see the [Rack website](https://rack.github.io/).| |db/|Contains your current database schema, as well as the database migrations.| -|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).| +|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](https://bundler.io).| |lib/|Extended modules for your application.| |log/|Application log files.| +|package.json|This file allows you to specify what npm dependencies are needed for your Rails application. This file is used by Yarn. For more information about Yarn, see the [Yarn website](https://yarnpkg.com/lang/en/).| |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.| +|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.md|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.| |test/|Unit tests, fixtures, and other test apparatus. These are covered in [Testing Rails Applications](testing.html).| |tmp/|Temporary files (like cache and pid files).| |vendor/|A place for all third-party code. In a typical Rails application this includes vendored gems.| +|.gitignore|This file tells git which files (or patterns) it should ignore. See [GitHub - Ignoring files](https://help.github.com/articles/ignoring-files) for more info about ignoring files. +|.ruby-version|This file contains the default Ruby version.| Hello, Rails! ------------- @@ -199,14 +209,14 @@ folder directly to the Ruby interpreter e.g. `ruby bin\rails server`. 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 +Usually macOS and Windows come with a JavaScript runtime installed. +Rails adds the `mini_racer` 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/rails/execjs#readme). -This will fire up WEBrick, a web server distributed with Ruby by default. To see +This will fire up Puma, a web server distributed with Rails 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: @@ -214,15 +224,14 @@ your application in action, open a browser window and navigate to 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 +cursor again. For most UNIX-like systems including macOS this will be a dollar sign `$`. In development mode, Rails does not generally require you to restart the server; changes you make in files will be automatically picked up by the server. The "Welcome aboard" page is the _smoke test_ for a new Rails application: it makes sure that you have your software configured correctly enough to serve a -page. You can also click on the _About your application's environment_ link to -see a summary of your application's environment. +page. ### Say "Hello", Rails @@ -243,11 +252,11 @@ Ruby) which is processed by the request cycle in Rails before being sent to the user. To create a new controller, you will need to run the "controller" generator and -tell it you want a controller called "welcome" with an action called "index", +tell it you want a controller called "Welcome" with an action called "index", just like this: ```bash -$ bin/rails generate controller welcome index +$ bin/rails generate controller Welcome index ``` Rails will create several files and a route for you. @@ -262,6 +271,7 @@ invoke test_unit create test/controllers/welcome_controller_test.rb invoke helper create app/helpers/welcome_helper.rb +invoke test_unit invoke assets invoke coffee create app/assets/javascripts/welcome.coffee @@ -296,32 +306,30 @@ Open the file `config/routes.rb` in your editor. 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 'welcome#index' - # - # ... + # For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.html +end ``` 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) +[DSL (domain-specific language)](https://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: +controllers and actions. +Edit this file by adding the line of code `root 'welcome#index'`. +It should look something like the following: ```ruby -root 'welcome#index' +Rails.application.routes.draw do + get 'welcome/index' + + root 'welcome#index' +end ``` `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 (`bin/rails generate controller welcome index`). +controller generator (`bin/rails generate controller Welcome index`). Launch the web server again if you stopped it to generate the controller (`bin/rails server`) and navigate to <http://localhost:3000> in your browser. You'll see the @@ -345,10 +353,11 @@ operations are referred to as _CRUD_ operations. 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: +`config/routes.rb` so the file will look as follows: ```ruby Rails.application.routes.draw do + get 'welcome/index' resources :articles @@ -356,35 +365,36 @@ Rails.application.routes.draw do end ``` -If you run `bin/rake routes`, you'll see that it has defined routes for all the +If you run `bin/rails 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 +$ bin/rails routes + Prefix Verb URI Pattern Controller#Action +welcome_index GET /welcome/index(.:format) welcome#index + 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 ``` 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: +create and read. The form for doing this will look like this:  It will look a little basic for now, but that's ok. We'll look at improving the styling for it afterwards. -### Laying down the ground work +### Laying down the groundwork 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 @@ -400,7 +410,7 @@ a controller called `ArticlesController`. You can do this by running this command: ```bash -$ bin/rails g controller articles +$ bin/rails generate controller Articles ``` If you open up the newly generated `app/controllers/articles_controller.rb` @@ -455,7 +465,7 @@ available, Rails will raise an exception. In the above image, the bottom line has been truncated. Let's see what the full error message looks like: ->Missing template articles/new, application/new with {locale:[:en], formats:[:html], handlers:[:erb, :builder, :coffee]}. Searched in: * "/path/to/blog/app/views" +>ArticlesController#new is missing a template for this request format and variant. request.formats: ["text/html"] request.variant: [] NOTE! For XHR/Ajax or API requests, this action would normally respond with 204 No Content: an empty white screen. Since you're loading it in a web browser, we assume that you expected to actually render a template, not… nothing, so we're showing an error to be extra-clear. If you expect 204 No Content, carry on. That's what you'll get from an XHR or API request. Give it a shot. That's quite a lot of text! Let's quickly go through and understand what each part of it means. @@ -465,27 +475,24 @@ The first part identifies which template is missing. In this case, it's the then it will attempt to load a template called `application/new`. It looks for one here because the `ArticlesController` 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 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 next part of the message contains `request.formats` which specifies +the format of template to be served in response. It is set to `text/html` as we +requested this page via browser, so Rails is looking for an HTML template. +`request.variant` specifies what kind of physical devices would be served by +the response and helps Rails determine which template to use in the response. +It is empty because no information has been provided. 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. +is the _handler_ that will be used to render the template. 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 default +handler for HTML is `erb`. Rails uses other handlers for other formats. +`builder` handler is used to build XML templates and `coffee` handler uses +CoffeeScript to build JavaScript templates. Since you want to create a new +HTML form, you will be using the `ERB` language which is designed to embed Ruby +in HTML. Therefore the file should be called `articles/new.html.erb` and needs to be located inside the `app/views` directory of the application. @@ -505,36 +512,36 @@ harmoniously! It's time to create the form for a new article. 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 +method called `form_with`. To use this method, add this code into `app/views/articles/new.html.erb`: ```html+erb -<%= form_for :article do |f| %> +<%= form_with scope: :article, local: true do |form| %> <p> - <%= f.label :title %><br> - <%= f.text_field :title %> + <%= form.label :title %><br> + <%= form.text_field :title %> </p> <p> - <%= f.label :text %><br> - <%= f.text_area :text %> + <%= form.label :text %><br> + <%= form.text_area :text %> </p> <p> - <%= f.submit %> + <%= form.submit %> </p> <% end %> ``` -If you refresh the page now, you'll see the exact same form as in the example. +If you refresh the page now, you'll see the exact same form from our example above. 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 `:article`. This tells the `form_for` +When you call `form_with`, you pass it an identifying scope for this +form. In this case, it's the symbol `:article`. This tells the `form_with` 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 +`FormBuilder` object - represented by `form` - 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. +`submit` on the `form` 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` @@ -543,33 +550,34 @@ 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`. +This can be done quite simply with the `:url` option of `form_with`. 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/articles/new.html.erb` to look like +Edit the `form_with` line inside `app/views/articles/new.html.erb` to look like this: ```html+erb -<%= form_for :article, url: articles_path do |f| %> +<%= form_with scope: :article, url: articles_path, local: true do |form| %> ``` 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 -`bin/rake routes`: +`bin/rails routes`: ```bash -$ bin/rake routes +$ bin/rails 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 +welcome_index GET /welcome/index(.:format) welcome#index + 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 ``` The `articles_path` helper tells Rails to point the form to the URI Pattern @@ -588,6 +596,10 @@ familiar error: You now need to create the `create` action within the `ArticlesController` for this to work. +NOTE: By default `form_with` submits forms using Ajax thereby skipping full page +redirects. To make this guide easier to get into we've disabled that with +`local: true` for now. + ### Creating articles To make the "Unknown action" go away, you can define a `create` action within @@ -604,9 +616,11 @@ class ArticlesController < 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 article to the database. +If you re-submit the form now, you may not see any change on the page. Don't worry! +This is because Rails by default returns `204 No Content` response for an action if +we don't specify what the response should be. We just added the `create` action +but didn't specify anything about how the response should be. In this case, the +`create` action should save 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 @@ -619,20 +633,19 @@ def create end ``` -The `render` method here is taking a very simple hash with a key of `plain` and +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 +method returns an `ActionController::Parameters` 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 see something that looks like the following: ```ruby -{"title"=>"First article!", "text"=>"This is my first article."} +<ActionController::Parameters {"title"=>"First Article!", "text"=>"This is my first article."} permitted: false> ``` This action is now displaying the parameters for the article that are coming in @@ -650,7 +663,7 @@ run this command in your terminal: $ bin/rails generate model Article title:string text:text ``` -With that command we told Rails that we want a `Article` model, together +With that command we told Rails that we want an `Article` model, together with a _title_ attribute of type string, and a _text_ attribute of type text. Those attributes are automatically added to the `articles` table in the database and mapped to the `Article` model. @@ -677,13 +690,13 @@ 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 CreateArticles < ActiveRecord::Migration +class CreateArticles < ActiveRecord::Migration[5.0] def change create_table :articles do |t| t.string :title t.text :text - t.timestamps null: false + t.timestamps end end end @@ -696,13 +709,13 @@ 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 [Active Record Migrations] +(active_record_migrations.html). -At this point, you can use a rake command to run the migration: +At this point, you can use a bin/rails command to run the migration: ```bash -$ bin/rake db:migrate +$ bin/rails db:migrate ``` Rails will execute this migration command and tell you it created the Articles @@ -719,7 +732,7 @@ NOTE. Because you're working in the development environment by default, this command will apply to the database defined in the `development` section of your `config/database.yml` file. If you would like to execute migrations in another environment, for instance in production, you must explicitly pass it when -invoking the command: `bin/rake db:migrate RAILS_ENV=production`. +invoking the command: `bin/rails db:migrate RAILS_ENV=production`. ### Saving data in the controller @@ -764,7 +777,7 @@ 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 +extra fields with values that violated your application's 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. @@ -806,7 +819,7 @@ 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 `bin/rake routes`, the route for `show` action is +As we have seen in the output of `bin/rails routes`, the route for `show` action is as follows: ``` @@ -823,7 +836,7 @@ 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. +before declaring `private` visibility in the controller. Given that, let's add the `show` action, as follows: @@ -836,7 +849,7 @@ class ArticlesController < ApplicationController def new end - # snipped for brevity + # snippet for brevity ``` A couple of things to note. We use `Article.find` to find the article we're @@ -868,7 +881,7 @@ Visit <http://localhost:3000/articles/new> and give it a try! ### Listing all articles We still need a way to list all our articles, so let's do that. -The route for this as per output of `bin/rake routes` is: +The route for this as per output of `bin/rails routes` is: ``` articles GET /articles(.:format) articles#index @@ -892,7 +905,7 @@ class ArticlesController < ApplicationController def new end - # snipped for brevity + # snippet for brevity ``` And then finally, add the view for this action, located at @@ -905,6 +918,7 @@ And then finally, add the view for this action, located at <tr> <th>Title</th> <th>Text</th> + <th></th> </tr> <% @articles.each do |article| %> @@ -950,7 +964,7 @@ Now, add another link in `app/views/articles/new.html.erb`, underneath the form, to go back to the `index` action: ```erb -<%= form_for :article, url: articles_path do |f| %> +<%= form_with scope: :article, url: articles_path, local: true do |form| %> ... <% end %> @@ -988,21 +1002,22 @@ and restart the web server when a change is made. The model file, `app/models/article.rb` is about as simple as it can get: ```ruby -class Article < ActiveRecord::Base +class Article < ApplicationRecord end ``` 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. +`ApplicationRecord`. `ApplicationRecord` inherits from `ActiveRecord::Base` +which 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. Rails includes methods to help you validate the data that you send to models. Open the `app/models/article.rb` file and edit it: ```ruby -class Article < ActiveRecord::Base +class Article < ApplicationRecord validates :title, presence: true, length: { minimum: 5 } end @@ -1060,7 +1075,7 @@ something went wrong. To do that, you'll modify `app/views/articles/new.html.erb` to check for error messages: ```html+erb -<%= form_for :article, url: articles_path do |f| %> +<%= form_with scope: :article, url: articles_path, local: true do |form| %> <% if @article.errors.any? %> <div id="error_explanation"> @@ -1077,17 +1092,17 @@ something went wrong. To do that, you'll modify <% end %> <p> - <%= f.label :title %><br> - <%= f.text_field :title %> + <%= form.label :title %><br> + <%= form.text_field :title %> </p> <p> - <%= f.label :text %><br> - <%= f.text_area :text %> + <%= form.label :text %><br> + <%= form.text_area :text %> </p> <p> - <%= f.submit %> + <%= form.submit %> </p> <% end %> @@ -1150,9 +1165,9 @@ new articles. Create a file called `app/views/articles/edit.html.erb` and make it look as follows: ```html+erb -<h1>Editing article</h1> +<h1>Edit article</h1> -<%= form_for :article, url: article_path(@article), method: :patch do |f| %> +<%= form_with(model: @article, local: true) do |form| %> <% if @article.errors.any? %> <div id="error_explanation"> @@ -1169,17 +1184,17 @@ it look as follows: <% end %> <p> - <%= f.label :title %><br> - <%= f.text_field :title %> + <%= form.label :title %><br> + <%= form.text_field :title %> </p> <p> - <%= f.label :text %><br> - <%= f.text_area :text %> + <%= form.label :text %><br> + <%= form.text_area :text %> </p> <p> - <%= f.submit %> + <%= form.submit %> </p> <% end %> @@ -1190,16 +1205,16 @@ it look as follows: This time we point the form to the `update` action, which is not defined yet but will be very soon. -The `method: :patch` option tells Rails that we want this form to be submitted +Passing the article object to the method, will automagically create url for submitting the edited article form. +This 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. -The first parameter of `form_for` can be an object, say, `@article` which would +The arguments to `form_with` could be model objects, say, `model: @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). +symbol scope (`scope: :article`) just creates the fields but without anything filled into them. +More details can be found in [form_with documentation] +(http://api.rubyonrails.org/classes/ActionView/Helpers/FormHelper.html#method-i-form_with). Next, we need to create the `update` action in `app/controllers/articles_controller.rb`. @@ -1240,10 +1255,9 @@ article we want to show the form back to the user. 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. +TIP: It is not necessary to pass all the attributes to `update`. For example, +if `@article.update(title: 'A new title')` was called, 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 articles, so let's add that now to `app/views/articles/index.html.erb` to make @@ -1297,7 +1311,7 @@ Create a new file `app/views/articles/_form.html.erb` with the following content: ```html+erb -<%= form_for @article do |f| %> +<%= form_with model: @article, local: true do |form| %> <% if @article.errors.any? %> <div id="error_explanation"> @@ -1314,29 +1328,29 @@ content: <% end %> <p> - <%= f.label :title %><br> - <%= f.text_field :title %> + <%= form.label :title %><br> + <%= form.text_field :title %> </p> <p> - <%= f.label :text %><br> - <%= f.text_area :text %> + <%= form.label :text %><br> + <%= form.text_area :text %> </p> <p> - <%= f.submit %> + <%= form.submit %> </p> <% end %> ``` -Everything except for the `form_for` declaration remained the same. -The reason we can use this shorter, simpler `form_for` declaration +Everything except for the `form_with` declaration remained the same. +The reason we can use this shorter, simpler `form_with` 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). +For more information about this use of `form_with`, see [Resource-oriented style] +(http://api.rubyonrails.org/classes/ActionView/Helpers/FormHelper.html#method-i-form_with-label-Resource-oriented+style). Now, let's update the `app/views/articles/new.html.erb` view to use this new partial, rewriting it completely: @@ -1363,7 +1377,7 @@ Then do the same for the `app/views/articles/edit.html.erb` view: 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 `bin/rake routes` is: +deleting articles as per output of `bin/rails routes` is: ```ruby DELETE /articles/:id(.:format) articles#destroy @@ -1483,15 +1497,15 @@ second argument, and then the options as another argument. The `method: :delete` and `data: { confirm: 'Are you sure?' }` 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 in your +JavaScript file `rails-ujs` which is automatically included in your application's layout (`app/views/layouts/application.html.erb`) when you generated the application. Without this file, the confirmation dialog box won't appear.  -TIP: Learn more about jQuery Unobtrusive Adapter (jQuery UJS) on -[Working With Javascript in Rails](working_with_javascript_in_rails.html) guide. +TIP: Learn more about Unobtrusive JavaScript on +[Working With JavaScript in Rails](working_with_javascript_in_rails.html) guide. Congratulations, you can now create, show, list, update and destroy articles. @@ -1510,7 +1524,7 @@ comments on articles. We're going to see the same generator that we used before when creating the `Article` model. This time we'll create a `Comment` model to hold -reference of article comments. Run this command in your terminal: +reference to an article. Run this command in your terminal: ```bash $ bin/rails generate model Comment commenter:string body:text article:references @@ -1528,7 +1542,7 @@ This command will generate four files: First, take a look at `app/models/comment.rb`: ```ruby -class Comment < ActiveRecord::Base +class Comment < ApplicationRecord belongs_to :article end ``` @@ -1537,32 +1551,34 @@ 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. +The (`:references`) keyword used in the bash command is a special data type for models. +It creates a new column on your database table with the provided model name appended with an `_id` +that can hold integer values. To get a better understanding, analyze the +`db/schema.rb` file after running the migration. + In addition to the model, Rails has also made a migration to create the corresponding database table: ```ruby -class CreateComments < ActiveRecord::Migration +class CreateComments < ActiveRecord::Migration[5.0] def change create_table :comments do |t| t.string :commenter t.text :body + t.references :article, foreign_key: true - # this line adds an integer column called `article_id`. - t.references :article, index: true - - t.timestamps null: false + t.timestamps 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. An index for this association is also created on this column. -Go ahead and run the migration: +The `t.references` line creates an integer column called `article_id`, an index +for it, and a foreign key constraint that points to the `id` column of the `articles` +table. Go ahead and run the migration: ```bash -$ bin/rake db:migrate +$ bin/rails db:migrate ``` Rails is smart enough to only execute the migrations that have not already been @@ -1572,8 +1588,6 @@ run against the current database, so in this case you will just see: == CreateComments: migrating ================================================= -- create_table(:comments) -> 0.0115s --- add_foreign_key(:comments, :articles) - -> 0.0000s == CreateComments: migrated (0.0119s) ======================================== ``` @@ -1591,7 +1605,7 @@ 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 +class Comment < ApplicationRecord belongs_to :article end ``` @@ -1600,7 +1614,7 @@ You'll need to edit `app/models/article.rb` to add the other side of the association: ```ruby -class Article < ActiveRecord::Base +class Article < ApplicationRecord has_many :comments validates :title, presence: true, length: { minimum: 5 } @@ -1651,8 +1665,8 @@ This creates five 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 | -| app/assets/javascripts/comment.coffee | CoffeeScript for the controller | -| app/assets/stylesheets/comment.scss | Cascading style sheet for the controller | +| app/assets/javascripts/comments.coffee | CoffeeScript for the controller | +| app/assets/stylesheets/comments.scss | Cascading style sheet for the controller | Like with any blog, our readers will create their comments directly after reading the article, and once they have added their comment, will be sent back @@ -1675,17 +1689,17 @@ So first, we'll wire up the Article show template </p> <h2>Add a comment:</h2> -<%= form_for([@article, @article.comments.build]) do |f| %> +<%= form_with(model: [ @article, @article.comments.build ], local: true) do |form| %> <p> - <%= f.label :commenter %><br> - <%= f.text_field :commenter %> + <%= form.label :commenter %><br> + <%= form.text_field :commenter %> </p> <p> - <%= f.label :body %><br> - <%= f.text_area :body %> + <%= form.label :body %><br> + <%= form.text_area :body %> </p> <p> - <%= f.submit %> + <%= form.submit %> </p> <% end %> @@ -1694,7 +1708,7 @@ So first, we'll wire up the Article show template ``` 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 +calling the `CommentsController` `create` action. The `form_with` call here uses 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`: @@ -1756,17 +1770,17 @@ add that to the `app/views/articles/show.html.erb`. <% end %> <h2>Add a comment:</h2> -<%= form_for([@article, @article.comments.build]) do |f| %> +<%= form_with(model: [ @article, @article.comments.build ], local: true) do |form| %> <p> - <%= f.label :commenter %><br> - <%= f.text_field :commenter %> + <%= form.label :commenter %><br> + <%= form.text_field :commenter %> </p> <p> - <%= f.label :body %><br> - <%= f.text_area :body %> + <%= form.label :body %><br> + <%= form.text_area :body %> </p> <p> - <%= f.submit %> + <%= form.submit %> </p> <% end %> @@ -1822,17 +1836,17 @@ following: <%= render @article.comments %> <h2>Add a comment:</h2> -<%= form_for([@article, @article.comments.build]) do |f| %> +<%= form_with(model: [ @article, @article.comments.build ], local: true) do |form| %> <p> - <%= f.label :commenter %><br> - <%= f.text_field :commenter %> + <%= form.label :commenter %><br> + <%= form.text_field :commenter %> </p> <p> - <%= f.label :body %><br> - <%= f.text_area :body %> + <%= form.label :body %><br> + <%= form.text_area :body %> </p> <p> - <%= f.submit %> + <%= form.submit %> </p> <% end %> @@ -1852,17 +1866,17 @@ 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([@article, @article.comments.build]) do |f| %> +<%= form_with(model: [ @article, @article.comments.build ], local: true) do |form| %> <p> - <%= f.label :commenter %><br> - <%= f.text_field :commenter %> + <%= form.label :commenter %><br> + <%= form.text_field :commenter %> </p> <p> - <%= f.label :body %><br> - <%= f.text_area :body %> + <%= form.label :body %><br> + <%= form.text_area :body %> </p> <p> - <%= f.submit %> + <%= form.submit %> </p> <% end %> ``` @@ -1966,7 +1980,7 @@ you to use the `dependent` option of an association to achieve this. Modify the Article model, `app/models/article.rb`, as follows: ```ruby -class Article < ActiveRecord::Base +class Article < ApplicationRecord has_many :comments, dependent: :destroy validates :title, presence: true, length: { minimum: 5 } @@ -2003,7 +2017,7 @@ class ArticlesController < ApplicationController @articles = Article.all end - # snipped for brevity + # snippet for brevity ``` We also want to allow only authenticated users to delete comments, so in the @@ -2019,7 +2033,7 @@ class CommentsController < ApplicationController # ... end - # snipped for brevity + # snippet for brevity ``` Now if you try to create a new article, you will be greeted with a basic HTTP diff --git a/guides/source/i18n.md b/guides/source/i18n.md index e8d0a83dd0..2b545e6b82 100644 --- a/guides/source/i18n.md +++ b/guides/source/i18n.md @@ -25,7 +25,7 @@ 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 +* How to use I18n to translate Active Record errors or Action Mailer E-mail subjects * Some other tools to go further with the translation process of your application -------------------------------------------------------------------------------- @@ -40,7 +40,7 @@ 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**. _Localization_ of a Rails application means defining translated values for these strings in desired languages. ### The Overall Architecture of the Library @@ -51,7 +51,7 @@ Thus, the Ruby I18n gem is split into two parts: 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. -NOTE: It is possible (or even desirable) to swap the shipped Simple backend with a more powerful one, which would store translation data in a relational database, GetText dictionary, or similar. See section [Using different backends](#using-different-backends) below. +NOTE: It is possible to swap the shipped Simple backend with a more powerful one, which would store translation data in a relational database, GetText dictionary, or similar. See section [Using different backends](#using-different-backends) below. ### The Public I18n API @@ -72,11 +72,13 @@ I18n.l Time.now There are also attribute readers and writers for the following attributes: ```ruby -load_path # Announce your custom translation files -locale # Get and set the current locale -default_locale # Get and set the default locale -exception_handler # Use a different exception_handler -backend # Use a different backend +load_path # Announce your custom translation files +locale # Get and set the current locale +default_locale # Get and set the default locale +available_locales # Whitelist locales available for the application +enforce_available_locales # Enforce locale whitelisting (true or false) +exception_handler # Use a different exception_handler +backend # Use a different backend ``` So, let's internationalize a simple Rails application from the ground up in the next chapters! @@ -84,13 +86,13 @@ So, let's internationalize a simple Rails application from the ground up in the Setup the Rails Application for Internationalization ---------------------------------------------------- -There are just a few simple steps to get up and running with I18n support for your application. +There are a few steps to get up and running with I18n support for a Rails application. ### Configure the I18n Module -Following the _convention over configuration_ philosophy, Rails will set up your application with reasonable defaults. If you need different settings, you can overwrite them easily. +Following the _convention over configuration_ philosophy, Rails I18n provides reasonable default translation strings. When different translation strings are needed, they can be overridden. -Rails adds all `.rb` and `.yml` files from the `config/locales` directory to your **translations load path**, automatically. +Rails adds all `.rb` and `.yml` files from the `config/locales` directory to the **translations load path**, automatically. The default `en.yml` locale in this directory contains a sample pair of translation strings: @@ -101,47 +103,43 @@ en: 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. +The I18n library will use **English** as a **default locale**, i.e. if a different locale is not set, `: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. Few gems such as [Globalize3](https://github.com/globalize/globalize) may help you implement it. +NOTE: The i18n library takes a **pragmatic approach** to locale keys (after [some discussion](https://groups.google.com/forum/#!topic/rails-i18n/FN7eLH2-lHA)), 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. +The **translations load path** (`I18n.load_path`) is an array of paths to files that will be loaded automatically. Configuring this path allows for customization of translations directory structure and file naming scheme. -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. +NOTE: The backend lazy-loads these translations when a translation is looked up for the first time. This backend can be swapped with something else even after translations have already been announced. -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. +You can change the default locale as well as configure the translations load paths in `config/application.rb` as follows: ```ruby -# The default locale is :en and all translations from config/locales/*.rb,yml are auto loaded. -# config.i18n.load_path += Dir[Rails.root.join('my', 'locales', '*.{rb,yml}').to_s] -# config.i18n.default_locale = :de + config.i18n.load_path += Dir[Rails.root.join('my', 'locales', '*.{rb,yml}').to_s] + config.i18n.default_locale = :de ``` -### Optional: Custom I18n Configuration Setup - -For the sake of completeness, let's mention that if you do not want to use the `application.rb` file for some reason, you can always wire up things manually, too. - -To tell the I18n library where it can find your custom translation files you can specify the load path anywhere in your application - just make sure it gets run before any translations are actually looked up. You might also want to change the default locale. The simplest thing possible is to put the following into an initializer: +The load path must be specified before any translations are looked up. To change the default locale from an initializer instead of `config/application.rb`: ```ruby -# in config/initializers/locale.rb +# config/initializers/locale.rb -# tell the I18n library where to find your translations +# Where the I18n library should search for translation files I18n.load_path += Dir[Rails.root.join('lib', 'locale', '*.{rb,yml}')] -# set default locale to something other than :en +# Whitelist locales available for the application +I18n.available_locales = [:en, :pt] + +# Set default locale to something other than :en I18n.default_locale = :pt ``` -### Setting and Passing the Locale - -If you want to translate your Rails application to a **single language other than English** (the default locale), you can set I18n.default_locale to your locale in `application.rb` or an initializer as shown above, and it will persist through the requests. +### Managing the Locale across Requests -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. +The default locale is used for all translations unless `I18n.locale` is explicitly set. -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. +A localized application will likely need to provide support for multiple locales. To accomplish this, the locale should be set at the beginning of each request so that all strings are translated using the desired locale during the lifetime of that request. -The _setting part_ is easy. You can set the locale in a `before_action` in the `ApplicationController` like this: +The locale can be set in a `before_action` in the `ApplicationController`: ```ruby before_action :set_locale @@ -151,11 +149,11 @@ def set_locale end ``` -This requires you to pass the locale as a URL query parameter as in `http://example.com/books?locale=pt`. (This is, for example, Google's approach.) So `http://localhost:3000?locale=pt` will load the Portuguese localization, whereas `http://localhost:3000?locale=de` would load the German localization, and so on. You may skip the next section and head over to the **Internationalize your application** section, if you want to try things out by manually placing the locale in the URL and reloading the page. +This example illustrates this using a URL query parameter to set the locale (e.g. `http://example.com/books?locale=pt`). With this approach, `http://localhost:3000?locale=pt` renders the Portuguese localization, while `http://localhost:3000?locale=de` loads a German localization. -Of course, you probably don't want to manually include the locale in every URL all over your application, or want the URLs look differently, e.g. the usual `http://example.com/pt/books` versus `http://example.com/en/books`. Let's discuss the different options you have. +The locale can be set using one of many different approaches. -### Setting the Locale from the Domain Name +#### Setting the Locale from the Domain Name One option you have is to set the locale from the domain name where your application runs. For example, we want `www.example.com` to load the English (or default) locale, and `www.example.es` to load the Spanish locale. Thus the _top-level domain name_ is used for locale setting. This has several advantages: @@ -173,7 +171,7 @@ def set_locale I18n.locale = extract_locale_from_tld || I18n.default_locale end -# Get locale from top-level domain or return nil if such locale is not available +# Get locale from top-level domain or return +nil+ if such locale is not available # You have to put something like: # 127.0.0.1 application.com # 127.0.0.1 application.it @@ -201,14 +199,14 @@ end If your application includes a locale switching menu, you would then have something like this in it: ```ruby -link_to("Deutsch", "#{APP_CONFIG[:deutsch_website_url]}#{request.env['REQUEST_URI']}") +link_to("Deutsch", "#{APP_CONFIG[:deutsch_website_url]}#{request.env['PATH_INFO']}") ``` assuming you would set `APP_CONFIG[:deutsch_website_url]` to some value like `http://www.application.de`. This solution has aforementioned advantages, however, you may not be able or may not want to provide different localizations ("language versions") on different domains. The most obvious solution would be to include locale code in the URL params (or request path). -### Setting the Locale from the URL Params +#### Setting the Locale from URL Params The most usual way of setting (and passing) the locale would be to include it in URL params, as we did in the `I18n.locale = params[:locale]` _before_action_ in the first example. We would like to have URLs like `www.example.com/books?locale=ja` or `www.example.com/ja/books` in this case. @@ -216,14 +214,14 @@ This approach has almost the same set of advantages as setting the locale from t 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/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). +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 `default_url_options`). We can include something like this in our `ApplicationController` then: ```ruby # app/controllers/application_controller.rb -def default_url_options(options = {}) - { locale: I18n.locale }.merge options +def default_url_options + { locale: I18n.locale } end ``` @@ -231,7 +229,7 @@ Every helper method dependent on `url_for` (e.g. helpers for named routes like ` You may be satisfied with this. It does impact the readability of URLs, though, when the locale "hangs" at the end of every URL in your application. Moreover, from the architectural standpoint, locale is usually hierarchically above the other parts of the application domain: and URLs should reflect this. -You probably want URLs to look like this: `www.example.com/en/books` (which loads the English locale) and `www.example.com/nl/books` (which loads the Dutch locale). This is achievable with the "over-riding `default_url_options`" strategy from above: you just have to set up your routes with [`scoping`](http://api.rubyonrails.org/classes/ActionDispatch/Routing/Mapper/Scoping.html) option in this way: +You probably want URLs to look like this: `http://www.example.com/en/books` (which loads the English locale) and `http://www.example.com/nl/books` (which loads the Dutch locale). This is achievable with the "over-riding `default_url_options`" strategy from above: you just have to set up your routes with [`scope`](http://api.rubyonrails.org/classes/ActionDispatch/Routing/Mapper/Scoping.html): ```ruby # config/routes.rb @@ -240,7 +238,9 @@ scope "/:locale" do end ``` -Now, when you call the `books_path` method you should get `"/en/books"` (for the default locale). An URL like `http://localhost:3001/nl/books` should load the Dutch locale, then, and following calls to `books_path` should return `"/nl/books"` (because the locale changed). +Now, when you call the `books_path` method you should get `"/en/books"` (for the default locale). A URL like `http://localhost:3001/nl/books` should load the Dutch locale, then, and following calls to `books_path` should return `"/nl/books"` (because the locale changed). + +WARNING. Since the return value of `default_url_options` is cached per request, the URLs in a locale selector cannot be generated invoking helpers in a loop that sets the corresponding `I18n.locale` in each iteration. Instead, leave `I18n.locale` untouched, and pass an explicit `:locale` option to the helper, or edit `request.original_fullpath`. If you don't want to force the use of a locale in your routes you can use an optional path scope (denoted by the parentheses) like so: @@ -253,7 +253,7 @@ end With this approach you will not get a `Routing Error` when accessing your resources such as `http://localhost:3001/books` without a locale. This is useful for when you want to use the default locale when one is not specified. -Of course, you need to take special care of the root URL (usually "homepage" or "dashboard") of your application. An URL like `http://localhost:3001/nl` will not work automatically, because the `root to: "books#index"` declaration in your `routes.rb` doesn't take locale into account. (And rightly so: there's only one "root" URL.) +Of course, you need to take special care of the root URL (usually "homepage" or "dashboard") of your application. A URL like `http://localhost:3001/nl` will not work automatically, because the `root to: "books#index"` declaration in your `routes.rb` doesn't take locale into account. (And rightly so: there's only one "root" URL.) You would probably need to map URLs like these: @@ -266,14 +266,23 @@ Do take special care about the **order of your routes**, so this route declarati 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 +#### Setting the Locale from User Preferences + +An application with authenticated users may allow users to set a locale preference through the application's interface. With this approach, a user's selected locale preference is persisted in the database and used to set the locale for authenticated requests by that user. + +```ruby +def set_locale + I18n.locale = current_user.try(:locale) || I18n.default_locale +end +``` -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. +#### Choosing an Implied Locale +When an explicit locale has not been set for a request (e.g. via one of the above methods), an application should attempt to infer the desired locale. -#### Using `Accept-Language` +##### Inferring Locale from the Language Header -One source of client supplied information would be an `Accept-Language` HTTP header. People may [set this in their browser](http://www.w3.org/International/questions/qa-lang-priorities) or other clients (such as _curl_). +The `Accept-Language` HTTP header indicates the preferred language for request's response. Browsers [set this header value based on the user's language preference settings](http://www.w3.org/International/questions/qa-lang-priorities), making it a good first choice when inferring a locale. A trivial implementation of using an `Accept-Language` header would be: @@ -290,24 +299,27 @@ private end ``` -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 +In practice, more robust code is necessary to do this reliably. Iain Hecker's [http_accept_language](https://github.com/iain/http_accept_language/tree/master) library or Ryan Tomayko's [locale](https://github.com/rack/rack-contrib/blob/master/lib/rack/contrib/locale.rb) Rack middleware provide solutions to this problem. + +##### Inferring the Locale from IP Geolocation -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. +The IP address of the client making the request can be used to infer the client's region and thus their locale. Services such as [GeoIP Lite Country](http://www.maxmind.com/app/geolitecountry) or gems like [geocoder](https://github.com/alexreisner/geocoder) can be used to implement this approach. -#### User Profile +In general, this approach is far less reliable than using the language header and is not recommended for most web applications. -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. +#### Storing the Locale from the Session or Cookies -Internationalizing your Application ------------------------------------ +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*](https://en.wikipedia.org/wiki/Representational_State_Transfer). Read more about the RESTful approach in [Stefan Tilkov's articles](https://www.infoq.com/articles/rest-introduction). Sometimes there are exceptions to this rule and those are discussed below. -OK! Now you've initialized I18n support for your Ruby on Rails application and told it which locale to use and how to preserve it between requests. With that in place, you're now ready for the really interesting stuff. +Internationalization and Localization +------------------------------------- + +OK! Now you've initialized I18n support for your Ruby on Rails application and told it which locale to use and how to preserve it between requests. -Let's _internationalize_ our application, i.e. abstract every locale-specific parts, and then _localize_ it, i.e. provide necessary translations for these abstracts. +Next we need to _internationalize_ our application by abstracting every locale-specific element. Finally, we need to _localize_ it by providing necessary translations for these abstracts. -You most probably have something like this in one of your applications: +Given the following example: ```ruby # config/routes.rb @@ -344,9 +356,9 @@ end  -### Adding Translations +### Abstracting Localized Code -Obviously there are **two strings that are localized to English**. In order to internationalize this code, **replace these strings** with calls to Rails' `#t` helper with a key that makes sense for the translation: +There are two strings in our code that are in English and that users will be rendered in our response ("Hello Flash" and "Hello World"). In order to internationalize this code, these strings need to be replaced by calls to Rails' `#t` helper with an appropriate key for each string: ```ruby # app/controllers/home_controller.rb @@ -359,17 +371,19 @@ end ```html+erb # app/views/home/index.html.erb -<h1><%=t :hello_world %></h1> +<h1><%= t :hello_world %></h1> <p><%= flash[:notice] %></p> ``` -When you now render this view, it will show an error message which tells you that the translations for the keys `:hello_world` and `:hello_flash` are missing. +Now, when this view is rendered, it will show an error message which tells you that the translations for the keys `:hello_world` and `:hello_flash` are missing.  NOTE: Rails adds a `t` (`translate`) helper method to your views so that you do not need to spell out `I18n.t` all the time. Additionally this helper will catch missing translations and wrap the resulting error message into a `<span class="translation_missing">`. -So let's add the missing translations into the dictionary files (i.e. do the "localization" part): +### Providing Translations for Internationalized Strings + +Add the missing translations into the translation dictionary files: ```yaml # config/locales/en.yml @@ -383,11 +397,11 @@ pirate: hello_flash: Ahoy Flash ``` -There you go. Because you haven't changed the default_locale, I18n will use English. Your application now shows: +Because the `default_locale` hasn't changed, translations use the `:en` locale and the response renders the english strings:  -And when you change the URL to pass the pirate locale (`http://localhost:3000?locale=pirate`), you'll get: +If the locale is set via the URL to the pirate locale (`http://localhost:3000?locale=pirate`), the response renders the pirate strings:  @@ -395,29 +409,101 @@ NOTE: You need to restart the server when you add new locale files. You may use YAML (`.yml`) or plain Ruby (`.rb`) files for storing your translations in SimpleStore. YAML is the preferred option among Rails developers. However, it has one big disadvantage. YAML is very sensitive to whitespace and special characters, so the application may not load your dictionary properly. Ruby files will crash your application on first request, so you may easily find what's wrong. (If you encounter any "weird issues" with YAML dictionaries, try putting the relevant portion of your dictionary into a Ruby file.) -### Passing variables to translations +If your translations are stored in YAML files, certain keys must be escaped. They are: + +* true, on, yes +* false, off, no -You can use variables in the translation messages and pass their values from the view. +Examples: + +```yaml +# config/locales/en.yml +en: + success: + 'true': 'True!' + 'on': 'On!' + 'false': 'False!' + failure: + true: 'True!' + off: 'Off!' + false: 'False!' +``` + +```ruby +I18n.t 'success.true' # => 'True!' +I18n.t 'success.on' # => 'On!' +I18n.t 'success.false' # => 'False!' +I18n.t 'failure.false' # => Translation Missing +I18n.t 'failure.off' # => Translation Missing +I18n.t 'failure.true' # => Translation Missing +``` + +### Passing Variables to Translations + +One key consideration for successfully internationalizing an application is to +avoid making incorrect assumptions about grammar rules when abstracting localized +code. Grammar rules that seem fundamental in one locale may not hold true in +another one. + +Improper abstraction is shown in the following example, where assumptions are +made about the ordering of the different parts of the translation. Note that Rails +provides a `number_to_currency` helper to handle the following case. ```erb -# app/views/home/index.html.erb -<%=t 'greet_username', user: "Bill", message: "Goodbye" %> +# app/views/products/show.html.erb +<%= "#{t('currency')}#{@product.price}" %> +``` + +```yaml +# config/locales/en.yml +en: + currency: "$" + +# config/locales/es.yml +es: + currency: "€" +``` + +If the product's price is 10 then the proper translation for Spanish is "10 €" +instead of "€10" but the abstraction cannot give it. + +To create proper abstraction, the I18n gem ships with a feature called variable +interpolation that allows you to use variables in translation definitions and +pass the values for these variables to the translation method. + +Proper abstraction is shown in the following example: + +```erb +# app/views/products/show.html.erb +<%= t('product_price', price: @product.price) %> ``` ```yaml # config/locales/en.yml en: - greet_username: "%{message}, %{user}!" + product_price: "$%{price}" + +# config/locales/es.yml +es: + product_price: "%{price} €" ``` +All grammatical and punctuation decisions are made in the definition itself, so +the abstraction can give a proper translation. + +NOTE: The `default` and `scope` keywords are reserved and can't be used as +variable names. If used, an `I18n::ReservedInterpolationKey` exception is raised. +If a translation expects an interpolation variable, but this has not been passed +to `#translate`, an `I18n::MissingInterpolationArgument` exception is raised. + ### 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. ```erb # app/views/home/index.html.erb -<h1><%=t :hello_world %></h1> -<p><%= flash[:notice] %></p +<h1><%= t :hello_world %></h1> +<p><%= flash[:notice] %></p> <p><%= l Time.now, format: :short %></p> ``` @@ -449,7 +535,10 @@ You can make use of this feature, e.g. when working with a large amount of stati ### Organization of Locale Files -When you are using the default SimpleStore shipped with the i18n library, dictionaries are stored in plain-text files on the disc. Putting translations for all parts of your application in one file per locale could be hard to manage. You can store these files in a hierarchy which makes sense to you. +When you are using the default SimpleStore shipped with the i18n library, +dictionaries are stored in plain-text files on the disk. Putting translations +for all parts of your application in one file per locale could be hard to +manage. You can store these files in a hierarchy which makes sense to you. For example, your `config/locales` directory could look like this: @@ -489,7 +578,9 @@ NOTE: The default locale loading mechanism in Rails does not load locale files i 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. +You should have a good understanding of using the i18n library now and know how +to internationalize a basic Rails application. In the following chapters, we'll +cover its 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). @@ -608,28 +699,17 @@ class BooksController < ApplicationController end ``` -### 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. - -All options besides `:default` and `:scope` that are passed to `#translate` will be interpolated to the translation: - -```ruby -I18n.backend.store_translations :en, thanks: 'Thanks %{name}!' -I18n.translate :thanks, name: 'Jeremy' -# => 'Thanks Jeremy!' -``` - -If a translation uses `:default` or `:scope` as an interpolation variable, an `I18n::ReservedInterpolationKey` exception is raised. If a translation expects an interpolation variable, but this has not been passed to `#translate`, an `I18n::MissingInterpolationArgument` exception is raised. - ### Pluralization -In English there are only one singular and one plural form for a given string, e.g. "1 message" and "2 messages". Other languages ([Arabic](http://unicode.org/repos/cldr-tmp/trunk/diff/supplemental/language_plural_rules.html#ar), [Japanese](http://unicode.org/repos/cldr-tmp/trunk/diff/supplemental/language_plural_rules.html#ja), [Russian](http://unicode.org/repos/cldr-tmp/trunk/diff/supplemental/language_plural_rules.html#ru) and many more) have different grammars that have additional or fewer [plural forms](http://unicode.org/repos/cldr-tmp/trunk/diff/supplemental/language_plural_rules.html). Thus, the I18n API provides a flexible pluralization feature. +In many languages — including English — there are only two forms, a singular and a plural, for +a given string, e.g. "1 message" and "2 messages". Other languages ([Arabic](http://www.unicode.org/cldr/charts/latest/supplemental/language_plural_rules.html#ar), [Japanese](http://www.unicode.org/cldr/charts/latest/supplemental/language_plural_rules.html#ja), [Russian](http://www.unicode.org/cldr/charts/latest/supplemental/language_plural_rules.html#ru) and many more) have different grammars that have additional or fewer [plural forms](http://cldr.unicode.org/index/cldr-spec/plural-rules). Thus, the I18n API provides a flexible pluralization feature. -The `:count` interpolation variable has a special role in that it both is interpolated to the translation and used to pick a pluralization from the translations according to the pluralization rules defined by CLDR: +The `:count` interpolation variable has a special role in that it both is interpolated to the translation and used to pick a pluralization from the translations according to the pluralization rules defined in the +pluralization backend. By default, only the English pluralization rules are applied. ```ruby I18n.backend.store_translations :en, inbox: { + zero: 'no messages', # optional one: 'one message', other: '%{count} messages' } @@ -638,18 +718,39 @@ I18n.translate :inbox, count: 2 I18n.translate :inbox, count: 1 # => 'one message' + +I18n.translate :inbox, count: 0 +# => 'no messages' ``` The algorithm for pluralizations in `:en` is as simple as: ```ruby -entry[count == 1 ? 0 : 1] +lookup_key = :zero if count == 0 && entry.has_key?(:zero) +lookup_key ||= count == 1 ? :one : :other +entry[lookup_key] ``` -I.e. the translation denoted as `:one` is regarded as singular, the other is used as plural (including the count being zero). +The translation denoted as `:one` is regarded as singular, and the `:other` is used as plural. If the count is zero, and a `:zero` entry is present, then it will be used instead of `:other`. If the lookup for the key does not return a Hash suitable for pluralization, an `I18n::InvalidPluralizationData` exception is raised. +#### Locale-specific rules + +The I18n gem provides a Pluralization backend that can be used to enable locale-specific rules. Include it +to the Simple backend, then add the localized pluralization algorithms to translation store, as `i18n.plural.rule`. + +```ruby +I18n::Backend::Simple.include(I18n::Backend::Pluralization) +I18n.backend.store_translations :pt, i18n: { plural: { rule: lambda { |n| [0, 1].include?(n) ? :one : :other } } } +I18n.backend.store_translations :pt, apples: { one: 'one or none', other: 'more than one' } + +I18n.t :apples, count: 0, locale: :pt +# => 'one or none' +``` + +Alternatively, the separate gem [rails-i18n](https://github.com/svenfuchs/rails-i18n) can be used to provide a fuller set of locale-specific pluralization rules. + ### Setting and Passing a Locale The locale can be either set pseudo-globally to `I18n.locale` (which uses `Thread.current` like, e.g., `Time.zone`) or can be passed as an option to `#translate` and `#localize`. @@ -761,6 +862,8 @@ en: Then `User.human_attribute_name("gender.female")` will return "Female". +NOTE: If you are using a class which includes `ActiveModel` and does not inherit from `ActiveRecord::Base`, replace `activerecord` with `activemodel` in the above key paths. + #### 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. @@ -770,7 +873,7 @@ This gives you quite powerful means to flexibly adjust your messages to your app Consider a User model with a validation for the name attribute like this: ```ruby -class User < ActiveRecord::Base +class User < ApplicationRecord validates :name, presence: true end ``` @@ -821,7 +924,7 @@ This way you can provide special translations for various error messages at diff #### Error Message Interpolation -The translated model name, translated attribute name, and value are always available for interpolation. +The translated model name, translated attribute name, and value are always available for interpolation as `model`, `attribute` and `value` respectively. 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}"`. @@ -843,6 +946,7 @@ So, for example, instead of the default error message `"cannot be blank"` you co | inclusion | - | :inclusion | - | | exclusion | - | :exclusion | - | | associated | - | :invalid | - | +| non-optional association | - | :required | - | | numericality | - | :not_a_number | - | | numericality | :greater_than | :greater_than | count | | numericality | :greater_than_or_equal_to | :greater_than_or_equal_to | count | @@ -873,7 +977,7 @@ 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'`. +gem by adding this line to your `Gemfile`: `gem 'dynamic_form'`. ### Translations for Action Mailer E-Mail Subjects @@ -946,7 +1050,7 @@ The Simple backend shipped with Active Support allows you to store translations For example a Ruby Hash providing translations can look like this: -```yaml +```ruby { pt: { foo: { @@ -1067,7 +1171,7 @@ Conclusion At this point you should have a good overview about how I18n support in Ruby on Rails works and are ready to start translating your project. -If you find anything missing or wrong in this guide, please file a ticket on our [issue tracker](http://i18n.lighthouseapp.com/projects/14948-rails-i18n/overview). If you want to discuss certain portions or have questions, please sign up to our [mailing list](http://groups.google.com/group/rails-i18n). +If you want to discuss certain portions or have questions, please sign up to the [rails-i18n mailing list](https://groups.google.com/forum/#!forum/rails-i18n). Contributing to Rails I18n @@ -1075,19 +1179,17 @@ 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 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 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!)) +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](https://groups.google.com/forum/#!forum/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). +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://help.github.com/articles/about-pull-requests/). Resources --------- -* [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. -* [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. +* [Google group: rails-i18n](https://groups.google.com/forum/#!forum/rails-i18n) - The project's mailing list. +* [GitHub: rails-i18n](https://github.com/svenfuchs/rails-i18n) - Code repository and issue tracker 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) - Code repository and issue tracker for the i18n gem. Authors @@ -1099,7 +1201,7 @@ Authors 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](https://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/initialization.md b/guides/source/initialization.md index 8fbb234698..c4f1df487b 100644 --- a/guides/source/initialization.md +++ b/guides/source/initialization.md @@ -3,8 +3,8 @@ The Rails Initialization Process ================================ -This guide explains the internals of the initialization process in Rails -as of Rails 4. It is an extremely in-depth guide and recommended for advanced Rails developers. +This guide explains the internals of the initialization process in Rails. +It is an extremely in-depth guide and recommended for advanced Rails developers. After reading this guide, you will know: @@ -16,7 +16,7 @@ After reading this guide, you will know: -------------------------------------------------------------------------------- This guide goes through every method call that is -required to boot up the Ruby on Rails stack for a default Rails 4 +required to boot up the Ruby on Rails stack for a default Rails 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. @@ -34,7 +34,7 @@ Launch! Let's start to boot and initialize the app. A Rails application is usually started by running `rails console` or `rails server`. -### `railties/bin/rails` +### `railties/exe/rails` The `rails` in the command `rails server` is a ruby executable in your load path. This executable contains the following lines: @@ -45,7 +45,7 @@ load Gem.bin_path('railties', 'rails', version) ``` 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 +`railties/exe/rails`. A part of the file `railties/exe/rails.rb` has the following code: ```ruby @@ -53,11 +53,11 @@ require "rails/cli" ``` The file `railties/lib/rails/cli` in turn calls -`Rails::AppRailsLoader.exec_app_rails`. +`Rails::AppLoader.exec_app`. -### `railties/lib/rails/app_rails_loader.rb` +### `railties/lib/rails/app_loader.rb` -The primary goal of the function `exec_app_rails` is to execute your app's +The primary goal of the function `exec_app` 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. @@ -74,7 +74,7 @@ This file is as follows: ```ruby #!/usr/bin/env ruby -APP_PATH = File.expand_path('../../config/application', __FILE__) +APP_PATH = File.expand_path('../config/application', __dir__) require_relative '../config/boot' require 'rails/commands' ``` @@ -86,36 +86,36 @@ The `APP_PATH` constant will be used later in `rails/commands`. The `config/boot `config/boot.rb` contains: ```ruby -# Set up gems listed in the Gemfile. -ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../../Gemfile', __FILE__) +ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../Gemfile', __dir__) -require 'bundler/setup' if File.exist?(ENV['BUNDLE_GEMFILE']) +require 'bundler/setup' # Set up gems listed in the 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 +`ENV['BUNDLE_GEMFILE']` to the location of this file. If the `Gemfile` 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: +* actioncable * actionmailer * actionpack * actionview +* activejob * activemodel * activerecord +* activestorage * activesupport * arel * builder * bundler -* erubis +* erubi * i18n * mail * mime-types * rack -* rack-cache -* rack-mount * rack-test * rails * railties @@ -131,7 +131,7 @@ Once `config/boot.rb` has finished, the next file that is required is `ARGV` array simply contains `server` which will be passed over: ```ruby -ARGV << '--help' if ARGV.empty? +require_relative "command" aliases = { "g" => "generate", @@ -139,38 +139,44 @@ aliases = { "c" => "console", "s" => "server", "db" => "dbconsole", - "r" => "runner" + "r" => "runner", + "t" => "test" } command = ARGV.shift command = aliases[command] || command -require 'rails/commands/commands_tasks' - -Rails::CommandsTasks.new(ARGV).run_command!(command) +Rails::Command.invoke command, ARGV ``` -TIP: As you can see, an empty ARGV list will make Rails show the help -snippet. - 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` +### `rails/command.rb` + +When one types a Rails command, `invoke` tries to lookup a command for the given +namespace and executes the command if found. + +If Rails doesn't recognize the command, it hands the reins over to Rake +to run a task of the same name. -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. +As shown, `Rails::Command` displays the help output automatically if the `args` +are empty. ```ruby -COMMAND_WHITELIST = %(plugin generate destroy console server dbconsole application runner new version help) +module Rails::Command + class << self + def invoke(namespace, args = [], **config) + namespace = namespace.to_s + namespace = "help" if namespace.blank? || HELP_MAPPINGS.include?(namespace) + namespace = "version" if %w( -v --version ).include? namespace -def run_command!(command) - command = parse_command(command) - if COMMAND_WHITELIST.include?(command) - send(command) - else - write_error_message(command) + if command = find_by_namespace(namespace) + command.perform(namespace, args, config) + else + find_by_namespace("rake").perform(namespace, args, config) + end + end end end ``` @@ -178,53 +184,39 @@ 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 +module Rails + module Command + class ServerCommand < Base # :nodoc: + def perform + set_application_directory! + + Rails::Server.new.tap do |server| + # Require application after server sets environment to propagate + # the --environment option. + require APP_PATH + Dir.chdir(Rails.application.root) + server.start + end + end + end end end - -def require_command!(command) - require "rails/commands/#{command}" -end ``` 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 -``` - -`fileutils` and `optparse` are standard Ruby libraries which provide helper functions for working with files and parsing options. +`config.ru` file isn't found. This then starts up the `Rails::Server` class. ### `actionpack/lib/action_dispatch.rb` Action Dispatch is the routing component of the Rails framework. It adds functionality like routing, session, and common middlewares. -### `rails/commands/server.rb` +### `rails/commands/server/server_command.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`: +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/server_command.rb`: ```ruby def initialize(*) @@ -250,7 +242,10 @@ end In this case, `options` will be `nil` so nothing happens in this method. -After `super` has finished in `Rack::Server`, we jump back to `rails/commands/server.rb`. At this point, `set_environment` is called within the context of the `Rails::Server` object and this method doesn't appear to do much at first glance: +After `super` has finished in `Rack::Server`, we jump back to +`rails/commands/server/server_command.rb`. At this point, `set_environment` +is called within the context of the `Rails::Server` object and this method +doesn't appear to do much at first glance: ```ruby def set_environment @@ -287,17 +282,15 @@ 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 => environment, - :pid => nil, - :Port => 9292, - :Host => default_host, - :AccessLog => [], - :config => "config.ru" - } + super.merge( + Port: ENV.fetch("PORT", 3000).to_i, + Host: ENV.fetch("HOST", "localhost").dup, + DoNotReverseLookup: true, + environment: (ENV["RAILS_ENV"] || ENV["RACK_ENV"] || "development").dup, + daemonize: false, + caching: nil, + pid: Options::DEFAULT_PID_PATH, + restart_cmd: restart_command) end ``` @@ -309,22 +302,25 @@ def opt_parser end ``` -The class **is** defined in `Rack::Server`, but is overwritten in `Rails::Server` to take different arguments. Its `parse!` method begins like this: +The class **is** defined in `Rack::Server`, but is overwritten in +`Rails::Server` to take different arguments. Its `parse!` method looks +like this: ```ruby def parse!(args) args, options = args.dup, {} - opt_parser = OptionParser.new do |opts| - opts.banner = "Usage: rails server [mongrel, thin, etc] [options]" - opts.on("-p", "--port=port", Integer, - "Runs Rails on the specified port.", "Default: 3000") { |v| options[:Port] = v } - ... + option_parser(options).parse! args + + options[:log_stdout] = options[:daemonize].blank? && (options[:environment] || Rails.env) == "development" + options[:server] = args.shift + options +end ``` This method will set up keys for the `options` which Rails will then be able to use to determine how its server should run. After `initialize` -has finished, we jump back into `rails/server` where `APP_PATH` (which was +has finished, we jump back into the server command where `APP_PATH` (which was set earlier) is required. ### `config/application` @@ -343,6 +339,7 @@ def start print_boot_information trap(:INT) { exit } create_tmp_directories + setup_dev_caching log_to_stdout if options[:log_stdout] super @@ -350,12 +347,9 @@ def start 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 def create_tmp_directories @@ -364,21 +358,30 @@ private end end + def setup_dev_caching + if options[:environment] == "development" + Rails::DevCaching.enable_by_argument(options[:caching]) + end + end + def log_to_stdout wrapped_app # touch the app so the logger is set up - console = ActiveSupport::Logger.new($stdout) + console = ActiveSupport::Logger.new(STDOUT) console.formatter = Rails.logger.formatter console.level = Rails.logger.level - Rails.logger.extend(ActiveSupport::Logger.broadcast(console)) + unless ActiveSupport::Logger.logger_outputs_to?(Rails.logger, STDOUT) + Rails.logger.extend(ActiveSupport::Logger.broadcast(console)) + end end ``` This is where the first output of the Rails initialization happens. This method creates a trap for `INT` signals, so if you `CTRL-C` the server, it will exit the process. As we can see from the code here, it will create the `tmp/cache`, -`tmp/pids`, and `tmp/sockets` directories. It then calls `wrapped_app` which is +`tmp/pids`, and `tmp/sockets` directories. It then enables caching in development +if `rails server` is called with `--dev-caching`. Finally, it calls `wrapped_app` which is responsible for creating the Rack app, before creating and assigning an instance of `ActiveSupport::Logger`. @@ -464,7 +467,7 @@ 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_relative 'config/environment' run <%= app_const %> ``` @@ -485,7 +488,7 @@ 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_relative 'config/environment' ``` ### `config/environment.rb` @@ -495,7 +498,7 @@ This file is the common file required by `config.ru` (`rails server`) and Passen This file begins with requiring `config/application.rb`: ```ruby -require File.expand_path('../application', __FILE__) +require_relative 'application' ``` ### `config/application.rb` @@ -503,7 +506,7 @@ require File.expand_path('../application', __FILE__) This file requires `config/boot.rb`: ```ruby -require File.expand_path('../boot', __FILE__) +require_relative 'boot' ``` But only if it hasn't been required before, which would be the case in `rails server` @@ -528,15 +531,18 @@ This file is responsible for requiring all the individual frameworks of Rails: require "rails" %w( - active_record - action_controller - action_view - action_mailer - rails/test_unit - sprockets -).each do |framework| + active_record/railtie + action_controller/railtie + action_view/railtie + action_mailer/railtie + active_job/railtie + action_cable/engine + active_storage/engine + rails/test_unit/railtie + sprockets/railtie +).each do |railtie| begin - require "#{framework}/railtie" + require railtie rescue LoadError end end @@ -555,9 +561,8 @@ I18n and Rails configuration are all being defined here. 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 +the application namespace, we go back to `config/environment.rb`. Here, the +application is initialized with `Rails.application.initialize!`, which is defined in `rails/application.rb`. ### `railties/lib/rails/application.rb` @@ -662,7 +667,7 @@ DEFAULT_OPTIONS = { } def self.run(app, options = {}) - options = DEFAULT_OPTIONS.merge(options) + options = DEFAULT_OPTIONS.merge(options) if options[:Verbose] app = Rack::CommonLogger.new(app, STDOUT) diff --git a/guides/source/kindle/layout.html.erb b/guides/source/kindle/layout.html.erb index f0a286210b..fd8746776b 100644 --- a/guides/source/kindle/layout.html.erb +++ b/guides/source/kindle/layout.html.erb @@ -14,12 +14,12 @@ <% if content_for? :header_section %> <%= yield :header_section %> - <div class="pagebreak"> + <div class="pagebreak"></div> <% end %> <% if content_for? :index_section %> <%= yield :index_section %> - <div class="pagebreak"> + <div class="pagebreak"></div> <% end %> <%= yield.html_safe %> diff --git a/guides/source/kindle/rails_guides.opf.erb b/guides/source/kindle/rails_guides.opf.erb index 547abcbc19..63eeb007d7 100644 --- a/guides/source/kindle/rails_guides.opf.erb +++ b/guides/source/kindle/rails_guides.opf.erb @@ -5,7 +5,7 @@ <meta name="cover" content="cover" /> <dc-metadata xmlns:dc="http://purl.org/dc/elements/1.1/"> - <dc:title>Ruby on Rails Guides (<%= @version %>)</dc:title> + <dc:title>Ruby on Rails Guides (<%= @version || "master@#{@edge[0, 7]}" %>)</dc:title> <dc:language>en-us</dc:language> <dc:creator>Ruby on Rails</dc:creator> diff --git a/guides/source/kindle/toc.html.erb b/guides/source/kindle/toc.html.erb index f310edd3a1..0f4228ed6b 100644 --- a/guides/source/kindle/toc.html.erb +++ b/guides/source/kindle/toc.html.erb @@ -14,7 +14,7 @@ Ruby on Rails Guides <% if document['work_in_progress']%>(WIP)<% end %> </li> <% end %> - </ul> + </ul> <% end %> <hr /> <ul> diff --git a/guides/source/kindle/toc.ncx.erb b/guides/source/kindle/toc.ncx.erb index 2c6d8e3bdf..5094fea4ca 100644 --- a/guides/source/kindle/toc.ncx.erb +++ b/guides/source/kindle/toc.ncx.erb @@ -32,12 +32,12 @@ </navPoint> <navPoint class="article" id="credits" playOrder="3"> <navLabel><text>Credits</text></navLabel> - <content src="credits.html"> + <content src="credits.html"/> </navPoint> <navPoint class="article" id="copyright" playOrder="4"> <navLabel><text>Copyright & License</text></navLabel> - <content src="copyright.html"> - </navPoint> + <content src="copyright.html"/> + </navPoint> </navPoint> <% play_order = 4 %> @@ -47,7 +47,7 @@ <text><%= section['name'] %></text> </navLabel> <content src="<%=section['documents'].first['url'] %>"/> - + <% section['documents'].each_with_index do |document, document_no| %> <navPoint class="article" id="_<%=section_no+1%>.<%=document_no+1%>" playOrder="<%=play_order +=1 %>"> <navLabel> diff --git a/guides/source/kindle/welcome.html.erb b/guides/source/kindle/welcome.html.erb index 610a71570f..ef3397f58f 100644 --- a/guides/source/kindle/welcome.html.erb +++ b/guides/source/kindle/welcome.html.erb @@ -2,4 +2,6 @@ <h3>Kindle Edition</h3> -The Kindle Edition of the Rails Guides should be considered a work in progress. Feedback is really welcome. Please see the "Feedback" section at the end of each guide for instructions. +<div> + The Kindle Edition of the Rails Guides should be considered a work in progress. Feedback is really welcome. Please see the "Feedback" section at the end of each guide for instructions. +</div> diff --git a/guides/source/layout.html.erb b/guides/source/layout.html.erb index 1005057ca9..3981199e95 100644 --- a/guides/source/layout.html.erb +++ b/guides/source/layout.html.erb @@ -29,14 +29,11 @@ More Ruby on Rails </span> <ul class="more-info-links s-hidden"> - <li class="more-info"><a href="http://rubyonrails.org/">Overview</a></li> - <li class="more-info"><a href="http://rubyonrails.org/download">Download</a></li> - <li class="more-info"><a href="http://rubyonrails.org/deploy">Deploy</a></li> - <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/community">Community</a></li> <li class="more-info"><a href="http://weblog.rubyonrails.org/">Blog</a></li> + <li class="more-info"><a href="http://guides.rubyonrails.org/">Guides</a></li> + <li class="more-info"><a href="http://api.rubyonrails.org/">API</a></li> + <li class="more-info"><a href="https://stackoverflow.com/questions/tagged/ruby-on-rails">Ask for help</a></li> + <li class="more-info"><a href="https://github.com/rails/rails">Contribute on GitHub</a></li> </ul> </div> </div> @@ -91,7 +88,7 @@ <div id="container"> <div class="wrapper"> <div id="mainCol"> - <%= yield.html_safe %> + <%= yield %> <h3>Feedback</h3> <p> @@ -102,9 +99,9 @@ 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. + You may also find incomplete content or stuff that is not up to date. Please do add any missing documentation for master. Make sure to check - <%= link_to 'Edge Guides','http://edgeguides.rubyonrails.org' %> first to verify + <%= 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. @@ -114,7 +111,7 @@ <%= link_to 'open an issue', 'https://github.com/rails/rails/issues' %>. </p> <p>And last but not least, any kind of discussion regarding Ruby on Rails - documentation is very welcome in the <%= link_to 'rubyonrails-docs mailing list', 'http://groups.google.com/group/rubyonrails-docs' %>. + documentation is very welcome on the <%= link_to 'rubyonrails-docs mailing list', 'https://groups.google.com/forum/#!forum/rubyonrails-docs' %>. </p> </div> </div> @@ -130,13 +127,11 @@ <script type="text/javascript" src="javascripts/jquery.min.js"></script> <script type="text/javascript" src="javascripts/responsive-tables.js"></script> <script type="text/javascript" src="javascripts/guides.js"></script> - <script type="text/javascript" src="javascripts/syntaxhighlighter/shCore.js"></script> - <script type="text/javascript" src="javascripts/syntaxhighlighter/shBrushRuby.js"></script> - <script type="text/javascript" src="javascripts/syntaxhighlighter/shBrushXml.js"></script> - <script type="text/javascript" src="javascripts/syntaxhighlighter/shBrushSql.js"></script> - <script type="text/javascript" src="javascripts/syntaxhighlighter/shBrushPlain.js"></script> + <script type="text/javascript" src="javascripts/syntaxhighlighter.js"></script> <script type="text/javascript"> - SyntaxHighlighter.all(); + syntaxhighlighterConfig = { + autoLinks: false, + }; $(guidesIndex.bind); </script> </body> diff --git a/guides/source/layouts_and_rendering.md b/guides/source/layouts_and_rendering.md index c57fa358d6..4d79b2db89 100644 --- a/guides/source/layouts_and_rendering.md +++ b/guides/source/layouts_and_rendering.md @@ -71,23 +71,25 @@ If we want to display the properties of all the books in our view, we can do so <h1>Listing Books</h1> <table> - <tr> - <th>Title</th> - <th>Summary</th> - <th></th> - <th></th> - <th></th> - </tr> - -<% @books.each do |book| %> - <tr> - <td><%= book.title %></td> - <td><%= book.content %></td> - <td><%= link_to "Show", book %></td> - <td><%= link_to "Edit", edit_book_path(book) %></td> - <td><%= link_to "Remove", book, method: :delete, data: { confirm: "Are you sure?" } %></td> - </tr> -<% end %> + <thead> + <tr> + <th>Title</th> + <th>Content</th> + <th colspan="3"></th> + </tr> + </thead> + + <tbody> + <% @books.each do |book| %> + <tr> + <td><%= book.title %></td> + <td><%= book.content %></td> + <td><%= link_to "Show", book %></td> + <td><%= link_to "Edit", edit_book_path(book) %></td> + <td><%= link_to "Destroy", book, method: :delete, data: { confirm: "Are you sure?" } %></td> + </tr> + <% end %> + </tbody> </table> <br> @@ -103,34 +105,6 @@ In most cases, the `ActionController::Base#render` method does the heavy lifting TIP: If you want to see the exact results of a call to `render` without needing to inspect it in a browser, you can call `render_to_string`. This method takes exactly the same options as `render`, but it returns a string instead of sending a response back to the browser. -#### Rendering Nothing - -Perhaps the simplest thing you can do with `render` is to render nothing at all: - -```ruby -render nothing: true -``` - -If you look at the response for this using cURL, you will see the following: - -```bash -$ curl -i 127.0.0.1:3000/books -HTTP/1.1 200 OK -Connection: close -Date: Sun, 24 Jan 2010 09:25:18 GMT -Transfer-Encoding: chunked -Content-Type: */*; charset=utf-8 -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. - -TIP: You should probably be using the `head` method, discussed later in this guide, instead of `render :nothing`. This provides additional flexibility and makes it explicit that you're only generating HTTP headers. - #### Rendering an Action's View If you want to render the view that corresponds to a different template within the same controller, you can use `render` with the name of the view: @@ -177,23 +151,22 @@ render template: "products/show" #### Rendering an Arbitrary File -The `render` method can also use a view that's entirely outside of your application (perhaps you're sharing views between two Rails applications): - -```ruby -render "/u/apps/warehouse_app/current/app/views/products/show" -``` - -Rails determines that this is a file render because of the leading slash character. To be explicit, you can use the `:file` option (which was required on Rails 2.2 and earlier): +The `render` method can also use a view that's entirely outside of your application: ```ruby 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. +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: Using the `:file` option in combination with users input can lead to security problems +since an attacker could use this action to access security sensitive files in your file system. 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. +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. #### Wrapping it up @@ -250,7 +223,7 @@ 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` +layout, you need to add the `layout: true` option and use the `.text.erb` extension for the layout file. #### Rendering HTML @@ -259,14 +232,14 @@ You can send an HTML string back to the browser by using the `:html` option to `render`: ```ruby -render html: "<strong>Not Found</strong>".html_safe +render html: helpers.tag.strong('Not Found') ``` 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: This option will escape HTML entities if the string is not HTML safe. +NOTE: When using `html:` option, HTML entities will be escaped if the string is not composed with `html_safe`-aware APIs. #### Rendering JSON @@ -308,11 +281,11 @@ 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 +the response. Using `:plain` or `:html` might be more appropriate 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. +`text/plain`, as that is the default content type of Action Dispatch response. #### Options for `render` @@ -388,7 +361,6 @@ Rails understands both numeric status codes and the corresponding symbols shown | | 303 | :see_other | | | 304 | :not_modified | | | 305 | :use_proxy | -| | 306 | :reserved | | | 307 | :temporary_redirect | | | 308 | :permanent_redirect | | **Client Error** | 400 | :bad_request | @@ -404,11 +376,12 @@ Rails understands both numeric status codes and the corresponding symbols shown | | 410 | :gone | | | 411 | :length_required | | | 412 | :precondition_failed | -| | 413 | :request_entity_too_large | -| | 414 | :request_uri_too_long | +| | 413 | :payload_too_large | +| | 414 | :uri_too_long | | | 415 | :unsupported_media_type | -| | 416 | :requested_range_not_satisfiable | +| | 416 | :range_not_satisfiable | | | 417 | :expectation_failed | +| | 421 | :misdirected_request | | | 422 | :unprocessable_entity | | | 423 | :locked | | | 424 | :failed_dependency | @@ -416,6 +389,7 @@ Rails understands both numeric status codes and the corresponding symbols shown | | 428 | :precondition_required | | | 429 | :too_many_requests | | | 431 | :request_header_fields_too_large | +| | 451 | :unavailable_for_legal_reasons | | **Server Error** | 500 | :internal_server_error | | | 501 | :not_implemented | | | 502 | :bad_gateway | @@ -441,6 +415,8 @@ render formats: :xml render formats: [:json, :xml] ``` +If a template with the specified format does not exist an `ActionView::MissingTemplate` error is raised. + #### 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. @@ -584,7 +560,7 @@ class Admin::ProductsController < AdminController end ``` -The lookup order for a `admin/products#index` action will be: +The lookup order for an `admin/products#index` action will be: * `app/views/admin/products/` * `app/views/admin/` @@ -651,12 +627,17 @@ Another way to handle returning responses to an HTTP request is with `redirect_t redirect_to photos_url ``` -You can use `redirect_to` with any arguments that you could use with `link_to` or `url_for`. There's also a special redirect that sends the user back to the page they just came from: +You can use `redirect_back` to return the user to the page they just came from. +This location is pulled from the `HTTP_REFERER` header which is not guaranteed +to be set by the browser, so you must provide the `fallback_location` +to use in this case. ```ruby -redirect_to :back +redirect_back(fallback_location: root_path) ``` +NOTE: `redirect_to` and `redirect_back` do not halt and return immediately from method execution, but simply set HTTP responses. Statements occurring after them in a method will be executed. You can halt by an explicit `return` or some other halting mechanism, if needed. + #### Getting a Different Redirect Status Code Rails uses HTTP status code 302, a temporary redirect, when you call `redirect_to`. If you'd like to use a different status code, perhaps 301, a permanent redirect, you can use the `:status` option: @@ -726,7 +707,7 @@ 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 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: +The `head` method can be used to send responses with only headers to the browser. The `head` method accepts a number or symbol (see [reference table](#the-status-option)) representing an 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 @@ -776,7 +757,7 @@ When Rails renders a view as a response, it does so by combining the view with t ### Asset Tag Helpers -Asset tag helpers provide methods for generating HTML that link views to feeds, JavaScript, stylesheets, images, videos and audios. There are six asset tag helpers available in Rails: +Asset tag helpers provide methods for generating HTML that link views to feeds, JavaScript, stylesheets, images, videos, and audios. There are six asset tag helpers available in Rails: * `auto_discovery_link_tag` * `javascript_include_tag` @@ -791,7 +772,7 @@ 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 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: +The `auto_discovery_link_tag` helper builds HTML that most browsers and feed readers can use to detect the presence of RSS, Atom, or JSON feeds. It takes the type of the link (`:rss`, `:atom`, or `:json`), 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"}, @@ -810,7 +791,7 @@ The `javascript_include_tag` helper returns an HTML `script` tag for each source If you are using Rails with the [Asset Pipeline](asset_pipeline.html) enabled, this helper will generate a link to `/assets/javascripts/` rather than `public/javascripts` which was used in earlier versions of Rails. This link is then served by the asset pipeline. -A JavaScript file within a Rails application or Rails engine goes in one of three locations: `app/assets`, `lib/assets` or `vendor/assets`. These locations are explained in detail in the [Asset Organization section in the Asset Pipeline Guide](asset_pipeline.html#asset-organization) +A JavaScript file within a Rails application or Rails engine goes in one of three locations: `app/assets`, `lib/assets` or `vendor/assets`. These locations are explained in detail in the [Asset Organization section in the Asset Pipeline Guide](asset_pipeline.html#asset-organization). You can specify a full path relative to the document root, or a URL, if you prefer. For example, to link to a JavaScript file that is inside a directory called `javascripts` inside of one of `app/assets`, `lib/assets` or `vendor/assets`, you would do this: @@ -1075,9 +1056,14 @@ One way to use partials is to treat them as the equivalent of subroutines: as a <%= render "shared/footer" %> ``` -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. +Here, the `_ad_banner.html.erb` and `_footer.html.erb` partials could contain +content that is shared by 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: +As seen in 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 up form layout +definitions for several similar resources: * `users/index.html.erb` @@ -1102,7 +1088,7 @@ As you already could see from the previous sections of this guide, `yield` is a * `shared/_search_filters.html.erb` ```html+erb - <%= form_for(@q) do |f| %> + <%= form_for(search) do |f| %> <h1>Search form:</h1> <fieldset> <%= yield f %> @@ -1175,23 +1161,21 @@ To pass a local variable to a partial in only specific cases use the `local_assi <%= render article, full: true %> ``` -* `_articles.html.erb` +* `_article.html.erb` ```erb - <%= content_tag_for :article, article do |article| %> - <h2><%= article.title %></h2> + <h2><%= article.title %></h2> - <% if local_assigns[:full] %> - <%= simple_format article.body %> - <% else %> - <%= truncate article.body %> - <% end %> + <% if local_assigns[:full] %> + <%= simple_format article.body %> + <% else %> + <%= truncate article.body %> <% end %> ``` This way it is possible to use the partial without the need to declare all local variables. -Every partial also has a local variable with the same name as the partial (minus the underscore). You can pass an object in to this local variable via the `:object` option: +Every partial also has a local variable with the same name as the partial (minus the leading underscore). You can pass an object in to this local variable via the `:object` option: ```erb <%= render partial: "customer", object: @new_customer %> @@ -1282,7 +1266,7 @@ You can also pass in arbitrary local variables to any partial you are rendering 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. +TIP: Rails also makes a counter variable available within a partial called by the collection, named after the title of the partial followed by `_counter`. For example, when rendering a collection `@products` the partial `_product.html.erb` can access the variable `product_counter` which indexes the number of times it has been rendered within the enclosing view. You can also specify a second partial to be rendered between instances of the main partial by using the `:spacer_template` option: @@ -1302,7 +1286,7 @@ When rendering collections it is also possible to use the `:layout` option: <%= render partial: "product", collection: @products, layout: "special_layout" %> ``` -The layout will be rendered together with the partial for each item in the collection. The current object and object_counter variables will be available in the layout as well, the same way they do within the partial. +The layout will be rendered together with the partial for each item in the collection. The current object and object_counter variables will be available in the layout as well, the same way they are within the partial. ### Using Nested Layouts diff --git a/guides/source/maintenance_policy.md b/guides/source/maintenance_policy.md index 50308f505a..1d6a4edb5b 100644 --- a/guides/source/maintenance_policy.md +++ b/guides/source/maintenance_policy.md @@ -44,7 +44,7 @@ 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). +**Currently included series:** `5.1.Z`. Security Issues --------------- @@ -59,7 +59,7 @@ 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`. +**Currently included series:** `5.1.Z`, `5.0.Z`. Severe Security Issues ---------------------- @@ -68,7 +68,7 @@ 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`. +**Currently included series:** `5.1.Z`, `5.0.Z`, `4.2.Z`. Unsupported Release Series -------------------------- diff --git a/guides/source/nested_model_forms.md b/guides/source/nested_model_forms.md deleted file mode 100644 index 1937369776..0000000000 --- a/guides/source/nested_model_forms.md +++ /dev/null @@ -1,230 +0,0 @@ -**DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON 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. - -After reading this guide, you will know: - -* do stuff. - --------------------------------------------------------------------------------- - -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 ------------ - -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 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. - -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=`. - -### ActiveRecord::Base model - -For an ActiveRecord::Base model and association this writer method is commonly defined with the `accepts_nested_attributes_for` class method: - -#### has_one - -```ruby -class Person < ActiveRecord::Base - has_one :address - accepts_nested_attributes_for :address -end -``` - -#### belongs_to - -```ruby -class Person < ActiveRecord::Base - belongs_to :firm - accepts_nested_attributes_for :firm -end -``` - -#### has_many / has_and_belongs_to_many - -```ruby -class Person < ActiveRecord::Base - has_many :projects - accepts_nested_attributes_for :projects -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 behavior: - -#### Single associated object - -```ruby -class Person - def address - Address.new - end - - def address_attributes=(attributes) - # ... - end -end -``` - -#### Association collection - -```ruby -class Person - def projects - [Project.new, Project.new] - end - - def projects_attributes=(attributes) - # ... - end -end -``` - -NOTE: See (TODO) in the advanced section for more information on how to deal with the CRUD operations in your custom model. - -Views ------ - -### Controller code - -A nested model form will _only_ be built if the associated object(s) exist. This means that for a new model instance you would probably want to build the associated object(s) first. - -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 < ApplicationController - def new - @person = Person.new - @person.built_address - 2.times { @person.projects.build } - end - - def create - @person = Person.new(params[:person]) - if @person.save - # ... - end - end -end -``` - -NOTE: Obviously the instantiation of the associated object(s) can become tedious and not DRY, so you might want to move that into the model itself. ActiveRecord::Base provides an `after_initialize` callback which is a good way to refactor this. - -### Form code - -Now that you have a model instance, with the appropriate methods and associated object(s), you can start building the nested model form. - -#### Standard form - -Start out with a regular RESTful form: - -```erb -<%= form_for @person do |f| %> - <%= f.text_field :name %> -<% end %> -``` - -This will generate the following html: - -```html -<form action="/people" class="new_person" id="new_person" method="post"> - <input id="person_name" name="person[name]" type="text" /> -</form> -``` - -#### Nested form for a single associated object - -Now add a nested form for the `address` association: - -```erb -<%= form_for @person do |f| %> - <%= f.text_field :name %> - - <%= f.fields_for :address do |af| %> - <%= af.text_field :street %> - <% end %> -<% end %> -``` - -This generates: - -```html -<form action="/people" class="new_person" id="new_person" method="post"> - <input id="person_name" name="person[name]" type="text" /> - - <input id="person_address_attributes_street" name="person[address_attributes][street]" type="text" /> -</form> -``` - -Notice that `fields_for` recognized the `address` as an association for which a nested model form should be built by the way it has namespaced the `name` attribute. - -When this form is posted the Rails parameter parser will construct a hash like the following: - -```ruby -{ - "person" => { - "name" => "Eloy Duran", - "address_attributes" => { - "street" => "Nieuwe Prinsengracht" - } - } -} -``` - -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 - -The form code for an association collection is pretty similar to that of a single associated object: - -```erb -<%= form_for @person do |f| %> - <%= f.text_field :name %> - - <%= f.fields_for :projects do |pf| %> - <%= pf.text_field :name %> - <% end %> -<% end %> -``` - -Which generates: - -```html -<form action="/people" class="new_person" id="new_person" method="post"> - <input id="person_name" name="person[name]" type="text" /> - - <input id="person_projects_attributes_0_name" name="person[projects_attributes][0][name]" type="text" /> - <input id="person_projects_attributes_1_name" name="person[projects_attributes][1][name]" type="text" /> -</form> -``` - -As you can see it has generated 2 `project name` inputs, one for each new `project` that was built in the controller's `new` action. Only this time the `name` attribute of the input contains a digit as an extra namespace. This will be parsed by the Rails parameter parser as: - -```ruby -{ - "person" => { - "name" => "Eloy Duran", - "projects_attributes" => { - "0" => { "name" => "Project 1" }, - "1" => { "name" => "Project 2" } - } - } -} -``` - -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 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/plugins.md b/guides/source/plugins.md index 4e630a39f3..15073af6be 100644 --- a/guides/source/plugins.md +++ b/guides/source/plugins.md @@ -17,7 +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 `ApplicationRecord` 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. @@ -30,14 +30,14 @@ Setup ----- Currently, Rails plugins are built as gems, _gemified plugins_. They can be shared across -different rails applications using RubyGems and Bundler if desired. +different Rails applications using RubyGems and Bundler if desired. ### Generate a gemified plugin. 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. Create your +to run integration tests using a dummy Rails application. Create your plugin with the command: ```bash @@ -54,7 +54,7 @@ Testing Your Newly Generated Plugin ----------------------------------- You can navigate to the directory that contains the plugin, run the `bundle install` command - and run the one generated test using the `rake` command. + and run the one generated test using the `bin/test` command. You should see: @@ -67,14 +67,14 @@ This will tell you that everything got generated properly and you are ready to s Extending Core Classes ---------------------- -This section will explain how to add a method to String that will be available anywhere in your rails application. +This section will explain how to add a method to String that will be available anywhere in your Rails application. In this example you will add a method to String named `to_squawk`. To begin, create a new test file with a few assertions: ```ruby # yaffle/test/core_ext_test.rb -require 'test_helper' +require "test_helper" class CoreExtTest < ActiveSupport::TestCase def test_to_squawk_prepends_the_word_squawk @@ -83,25 +83,37 @@ class CoreExtTest < ActiveSupport::TestCase end ``` -Run `rake` to run the test. This test should fail because we haven't implemented the `to_squawk` method: +Run `bin/test` to run the test. This test should fail because we haven't implemented the `to_squawk` method: ```bash - 1) Error: - 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' +E + +Error: +CoreExtTest#test_to_squawk_prepends_the_word_squawk: +NoMethodError: undefined method `to_squawk' for "Hello World":String + + +bin/test /path/to/yaffle/test/core_ext_test.rb:4 + +. + +Finished in 0.003358s, 595.6483 runs/s, 297.8242 assertions/s. + +2 runs, 1 assertions, 0 failures, 1 errors, 0 skips ``` Great - now you are ready to start development. -In `lib/yaffle.rb`, add `require 'yaffle/core_ext'`: +In `lib/yaffle.rb`, add `require "yaffle/core_ext"`: ```ruby # yaffle/lib/yaffle.rb -require 'yaffle/core_ext' +require "yaffle/railtie" +require "yaffle/core_ext" module Yaffle + # Your code goes here... end ``` @@ -110,20 +122,20 @@ Finally, create the `core_ext.rb` file and add the `to_squawk` method: ```ruby # yaffle/lib/yaffle/core_ext.rb -String.class_eval do +class String def to_squawk "squawk! #{self}".strip end end ``` -To test that your method does what it says it does, run the unit tests with `rake` from your plugin directory. +To test that your method does what it says it does, run the unit tests with `bin/test` from your plugin directory. ```bash 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: +To see this in action, change to the `test/dummy` directory, fire up a console and start squawking: ```bash $ bin/rails console @@ -142,7 +154,7 @@ To begin, set up your files so that you have: ```ruby # yaffle/test/acts_as_yaffle_test.rb -require 'test_helper' +require "test_helper" class ActsAsYaffleTest < ActiveSupport::TestCase end @@ -151,10 +163,12 @@ end ```ruby # yaffle/lib/yaffle.rb -require 'yaffle/core_ext' -require 'yaffle/acts_as_yaffle' +require "yaffle/railtie" +require "yaffle/core_ext" +require "yaffle/acts_as_yaffle" module Yaffle + # Your code goes here... end ``` @@ -163,7 +177,6 @@ end module Yaffle module ActsAsYaffle - # your code will go here end end ``` @@ -179,10 +192,9 @@ To start out, write a failing test that shows the behavior you'd like: ```ruby # yaffle/test/acts_as_yaffle_test.rb -require 'test_helper' +require "test_helper" class ActsAsYaffleTest < ActiveSupport::TestCase - def test_a_hickwalls_yaffle_text_field_should_be_last_squawk assert_equal "last_squawk", Hickwall.yaffle_text_field end @@ -190,29 +202,42 @@ class ActsAsYaffleTest < ActiveSupport::TestCase def test_a_wickwalls_yaffle_text_field_should_be_last_tweet assert_equal "last_tweet", Wickwall.yaffle_text_field end - end ``` -When you run `rake`, you should see the following: +When you run `bin/test`, you should see the following: ``` - 1) Error: - ActsAsYaffleTest#test_a_hickwalls_yaffle_text_field_should_be_last_squawk: - NameError: uninitialized constant ActsAsYaffleTest::Hickwall - /path/to/yaffle/test/acts_as_yaffle_test.rb:6:in `test_a_hickwalls_yaffle_text_field_should_be_last_squawk' +# Running: + +..E + +Error: +ActsAsYaffleTest#test_a_wickwalls_yaffle_text_field_should_be_last_tweet: +NameError: uninitialized constant ActsAsYaffleTest::Wickwall + + +bin/test /path/to/yaffle/test/acts_as_yaffle_test.rb:8 + +E + +Error: +ActsAsYaffleTest#test_a_hickwalls_yaffle_text_field_should_be_last_squawk: +NameError: uninitialized constant ActsAsYaffleTest::Hickwall - 2) Error: - ActsAsYaffleTest#test_a_wickwalls_yaffle_text_field_should_be_last_tweet: - NameError: uninitialized constant ActsAsYaffleTest::Wickwall - /path/to/yaffle/test/acts_as_yaffle_test.rb:10:in `test_a_wickwalls_yaffle_text_field_should_be_last_tweet' - 4 runs, 2 assertions, 0 failures, 2 errors, 0 skips +bin/test /path/to/yaffle/test/acts_as_yaffle_test.rb:4 + + + +Finished in 0.004812s, 831.2949 runs/s, 415.6475 assertions/s. + +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. We can easily generate these models in our "dummy" Rails application by running the following commands from the -test/dummy directory: +`test/dummy` directory: ```bash $ cd test/dummy @@ -225,7 +250,7 @@ and migrating the database. First, run: ```bash $ cd test/dummy -$ bin/rake db:migrate +$ bin/rails db:migrate ``` While you are here, change the Hickwall and Wickwall models so that they know that they are supposed to act @@ -234,57 +259,70 @@ like yaffles. ```ruby # test/dummy/app/models/hickwall.rb -class Hickwall < ActiveRecord::Base +class Hickwall < ApplicationRecord acts_as_yaffle end # test/dummy/app/models/wickwall.rb -class Wickwall < ActiveRecord::Base +class Wickwall < ApplicationRecord acts_as_yaffle yaffle_text_field: :last_tweet end - ``` We will also add code to define the `acts_as_yaffle` method. ```ruby # yaffle/lib/yaffle/acts_as_yaffle.rb + module Yaffle module ActsAsYaffle extend ActiveSupport::Concern - included do - end - - module ClassMethods + class_methods do def acts_as_yaffle(options = {}) - # your code will go here end end end end -ActiveRecord::Base.include(Yaffle::ActsAsYaffle) +# test/dummy/app/models/application_record.rb + +class ApplicationRecord < ActiveRecord::Base + include Yaffle::ActsAsYaffle + + self.abstract_class = true +end ``` -You can then return to the root directory (`cd ../..`) of your plugin and rerun the tests using `rake`. +You can then return to the root directory (`cd ../..`) of your plugin and rerun the tests using `bin/test`. ``` - 1) Error: - 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' +# Running: + +.E - 2) Error: - 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' +Error: +ActsAsYaffleTest#test_a_hickwalls_yaffle_text_field_should_be_last_squawk: +NoMethodError: undefined method `yaffle_text_field' for #<Class:0x0055974ebbe9d8> - 4 runs, 2 assertions, 0 failures, 2 errors, 0 skips +bin/test /path/to/yaffle/test/acts_as_yaffle_test.rb:4 + +E + +Error: +ActsAsYaffleTest#test_a_wickwalls_yaffle_text_field_should_be_last_tweet: +NoMethodError: undefined method `yaffle_text_field' for #<Class:0x0055974eb8cfc8> + + +bin/test /path/to/yaffle/test/acts_as_yaffle_test.rb:8 + +. + +Finished in 0.008263s, 484.0999 runs/s, 242.0500 assertions/s. + +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. @@ -294,24 +332,26 @@ Getting closer... Now we will implement the code of the `acts_as_yaffle` method module Yaffle module ActsAsYaffle - extend ActiveSupport::Concern - - included do - end + extend ActiveSupport::Concern - module ClassMethods + class_methods do def acts_as_yaffle(options = {}) - cattr_accessor :yaffle_text_field - self.yaffle_text_field = (options[:yaffle_text_field] || :last_squawk).to_s + cattr_accessor :yaffle_text_field, default: (options[:yaffle_text_field] || :last_squawk).to_s end end end end -ActiveRecord::Base.include(Yaffle::ActsAsYaffle) +# test/dummy/app/models/application_record.rb + +class ApplicationRecord < ActiveRecord::Base + include Yaffle::ActsAsYaffle + + self.abstract_class = true +end ``` -When you run `rake`, you should see the tests all pass: +When you run `bin/test`, you should see the tests all pass: ```bash 4 runs, 4 assertions, 0 failures, 0 errors, 0 skips @@ -319,17 +359,16 @@ When you run `rake`, you should see the tests all pass: ### Add an Instance Method -This plugin will add a method named 'squawk' to any Active Record object that calls 'acts_as_yaffle'. The 'squawk' +This plugin will add a method named 'squawk' to any Active Record object that calls `acts_as_yaffle`. The 'squawk' method will simply set the value of one of the fields in the database. To start out, write a failing test that shows the behavior you'd like: ```ruby # yaffle/test/acts_as_yaffle_test.rb -require 'test_helper' +require "test_helper" class ActsAsYaffleTest < ActiveSupport::TestCase - def test_a_hickwalls_yaffle_text_field_should_be_last_squawk assert_equal "last_squawk", Hickwall.yaffle_text_field end @@ -353,7 +392,7 @@ end ``` Run the test to make sure the last two tests fail with an error that contains "NoMethodError: undefined method `squawk'", -then update 'acts_as_yaffle.rb' to look like this: +then update `acts_as_yaffle.rb` to look like this: ```ruby # yaffle/lib/yaffle/acts_as_yaffle.rb @@ -363,29 +402,29 @@ module Yaffle extend ActiveSupport::Concern included do - end - - module ClassMethods - def acts_as_yaffle(options = {}) - cattr_accessor :yaffle_text_field - self.yaffle_text_field = (options[:yaffle_text_field] || :last_squawk).to_s - - include Yaffle::ActsAsYaffle::LocalInstanceMethods + def squawk(string) + write_attribute(self.class.yaffle_text_field, string.to_squawk) end end - module LocalInstanceMethods - def squawk(string) - write_attribute(self.class.yaffle_text_field, string.to_squawk) + class_methods do + def acts_as_yaffle(options = {}) + cattr_accessor :yaffle_text_field, default: (options[:yaffle_text_field] || :last_squawk).to_s end end end end -ActiveRecord::Base.include(Yaffle::ActsAsYaffle) +# test/dummy/app/models/application_record.rb + +class ApplicationRecord < ActiveRecord::Base + include Yaffle::ActsAsYaffle + + self.abstract_class = true +end ``` -Run `rake` one final time and you should see: +Run `bin/test` one final time and you should see: ``` 6 runs, 6 assertions, 0 failures, 0 errors, 0 skips @@ -400,23 +439,23 @@ send("#{self.class.yaffle_text_field}=", string.to_squawk) 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) +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 ------------------- Gem plugins currently in development can easily be shared from any Git repository. To share the Yaffle gem with others, simply -commit the code to a Git repository (like GitHub) and add a line to the Gemfile of the application in question: +commit the code to a Git repository (like GitHub) and add a line to the `Gemfile` of the application in question: ```ruby -gem 'yaffle', git: 'git://github.com/yaffle_watcher/yaffle.git' +gem "yaffle", git: "https://github.com/rails/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). +When the gem is ready to be shared as a formal release, it can be published to [RubyGems](https://rubygems.org). +For more information about publishing gems to RubyGems, see: [Publishing your gem](http://guides.rubygems.org/publishing). RDoc Documentation ------------------ @@ -430,7 +469,7 @@ The first step is to update the README file with detailed information about how * How to add the functionality to the app (several examples of common use cases) * Warnings, gotchas or tips that might help users and save them time -Once your README is solid, go through and add rdoc comments to all of the methods that developers will use. It's also customary to add '#:nodoc:' comments to those parts of the code that are not included in the public API. +Once your README is solid, go through and add rdoc comments to all of the methods that developers will use. It's also customary to add `#:nodoc:` comments to those parts of the code that are not included in the public API. Once your comments are good to go, navigate to your plugin directory and run: @@ -443,4 +482,3 @@ $ bundle exec rake rdoc * [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://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 deleted file mode 100644 index ce093f78ba..0000000000 --- a/guides/source/profiling.md +++ /dev/null @@ -1,16 +0,0 @@ -*DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON 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 b3e1874048..e087834a2f 100644 --- a/guides/source/rails_application_templates.md +++ b/guides/source/rails_application_templates.md @@ -15,18 +15,18 @@ 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 the -m option. This can either be a 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 $ 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. +You can use the `app:template` Rake task to apply templates to an existing Rails application. The location of the template needs to be passed in via the LOCATION environment variable. Again, this can either be path to a file or a URL. ```bash -$ bin/rake rails:template LOCATION=~/template.rb -$ bin/rake rails:template LOCATION=http://example.com/template.rb +$ bin/rails app:template LOCATION=~/template.rb +$ bin/rails app:template LOCATION=http://example.com/template.rb ``` Template API @@ -38,7 +38,7 @@ The Rails templates API is easy to understand. Here's an example of a typical Ra # template.rb generate(:scaffold, "person name:string") route "root to: 'people#index'" -rake("db:migrate") +rails_command("db:migrate") after_bundle do git :init @@ -78,7 +78,7 @@ gem_group :development, :test do end ``` -### add_source(source, options = {}) +### add_source(source, options={}, &block) Adds the given source to the generated application's `Gemfile`. @@ -88,6 +88,14 @@ For example, if you need to source a gem from `"http://code.whytheluckystiff.net add_source "http://code.whytheluckystiff.net" ``` +If block is given, gem entries in block are wrapped into the source group. + +```ruby +add_source "http://gems.github.com/" do + gem "rspec-rails" +end +``` + ### environment/application(data=nil, options={}, &block) Adds a line inside the `Application` class for `config/application.rb`. @@ -167,18 +175,24 @@ Executes an arbitrary command. Just like the backticks. Let's say you want to re run "rm README.rdoc" ``` -### rake(command, options = {}) +### rails_command(command, options = {}) + +Runs the supplied task in the Rails application. Let's say you want to migrate the database: + +```ruby +rails_command "db:migrate" +``` -Runs the supplied rake tasks in the Rails application. Let's say you want to migrate the database: +You can also run tasks with a different Rails environment: ```ruby -rake "db:migrate" +rails_command "db:migrate", env: 'production' ``` -You can also run rake tasks with a different Rails environment: +You can also run tasks as a super-user: ```ruby -rake "db:migrate", env: 'production' +rails_command "log:clear", sudo: true ``` ### route(routing_code) @@ -215,10 +229,10 @@ CODE ### yes?(question) or no?(question) -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: +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?") +rails_command("rails:freeze:gems") if yes?("Freeze rails gems?") # no?(question) acts just the opposite. ``` @@ -263,6 +277,6 @@ relative paths to your template's location. ```ruby def source_paths - [File.expand_path(File.dirname(__FILE__))] + [__dir__] end ``` diff --git a/guides/source/rails_on_rack.md b/guides/source/rails_on_rack.md index 993cd5ac44..5718b9ddfc 100644 --- a/guides/source/rails_on_rack.md +++ b/guides/source/rails_on_rack.md @@ -20,9 +20,9 @@ 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.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. +Explaining how Rack works 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. Rails on Rack ------------- @@ -58,33 +58,13 @@ class Server < ::Rack::Server end ``` -Here's how it loads the middlewares: - -```ruby -def middleware - middlewares = [] - middlewares << [::Rack::ContentLength] - Hash.new(middlewares) -end -``` - -`Rails::Rack::Debugger` is primarily useful only in the development environment. The following table explains the usage of the loaded middlewares: - -| Middleware | Purpose | -| ----------------------- | --------------------------------------------------------------------------------- | -| `Rails::Rack::Debugger` | Starts Debugger | -| `Rack::ContentLength` | Counts the number of bytes in the response and set the HTTP Content-Length header | - ### `rackup` To use `rackup` instead of Rails' `rails server`, you can put the following inside `config.ru` of your Rails application's root directory: ```ruby # Rails.root/config.ru -require ::File.expand_path('../config/environment', __FILE__) - -use Rails::Rack::Debugger -use Rack::ContentLength +require_relative 'config/environment' run Rails.application ``` @@ -94,7 +74,7 @@ And start the server: $ rackup config.ru ``` -To find out more about different `rackup` options: +To find out more about different `rackup` options, you can run: ```bash $ rackup --help @@ -109,14 +89,15 @@ Action Dispatcher Middleware Stack 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. +NOTE: `ActionDispatch::MiddlewareStack` is Rails' equivalent of `Rack::Builder`, +but is built for better flexibility and more features to meet Rails' requirements. ### Inspecting Middleware Stack -Rails has a handy rake task for inspecting the middleware stack in use: +Rails has a handy task for inspecting the middleware stack in use: ```bash -$ bin/rake middleware +$ bin/rails middleware ``` For a freshly generated Rails application, this might produce something like: @@ -124,28 +105,28 @@ 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> +use ActionDispatch::Executor +use ActiveSupport::Cache::Strategy::LocalCache::Middleware use Rack::Runtime use Rack::MethodOverride use ActionDispatch::RequestId +use ActionDispatch::RemoteIp +use Sprockets::Rails::QuietAssets use Rails::Rack::Logger use ActionDispatch::ShowExceptions +use WebConsole::Middleware 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 use ActionDispatch::Session::CookieStore use ActionDispatch::Flash -use ActionDispatch::ParamsParser +use ActionDispatch::ContentSecurityPolicy::Middleware use Rack::Head use Rack::ConditionalGet use Rack::ETag -run Rails.application.routes +run MyApp::Application.routes ``` The default middlewares shown here (and some others) are each summarized in the [Internal Middlewares](#internal-middleware-stack) section, below. @@ -170,9 +151,9 @@ You can add a new middleware to the middleware stack using any of the following # Push Rack::BounceFavicon at the bottom config.middleware.use Rack::BounceFavicon -# Add Lifo::Cache after ActiveRecord::QueryCache. +# Add Lifo::Cache after ActionDispatch::Executor. # Pass { page_cache: false } argument to Lifo::Cache. -config.middleware.insert_after ActiveRecord::QueryCache, Lifo::Cache, page_cache: false +config.middleware.insert_after ActionDispatch::Executor, Lifo::Cache, page_cache: false ``` #### Swapping a Middleware @@ -192,18 +173,17 @@ Add the following lines to your application configuration: ```ruby # config/application.rb -config.middleware.delete "Rack::Lock" +config.middleware.delete Rack::Runtime ``` -And now if you inspect the middleware stack, you'll find that `Rack::Lock` is +And now if you inspect the middleware stack, you'll find that `Rack::Runtime` is not a part of it. ```bash -$ bin/rake middleware +$ bin/rails middleware (in /Users/lifo/Rails/blog) use ActionDispatch::Static use #<ActiveSupport::Cache::Strategy::LocalCache::Middleware:0x00000001c304c8> -use Rack::Runtime ... run Rails.application.routes ``` @@ -212,16 +192,16 @@ If you want to remove session related middleware, do the following: ```ruby # config/application.rb -config.middleware.delete "ActionDispatch::Cookies" -config.middleware.delete "ActionDispatch::Session::CookieStore" -config.middleware.delete "ActionDispatch::Flash" +config.middleware.delete ActionDispatch::Cookies +config.middleware.delete ActionDispatch::Session::CookieStore +config.middleware.delete ActionDispatch::Flash ``` And to remove browser related middleware, ```ruby # config/application.rb -config.middleware.delete "Rack::MethodOverride" +config.middleware.delete Rack::MethodOverride ``` ### Internal Middleware Stack @@ -234,12 +214,16 @@ Much of Action Controller's functionality is implemented as Middlewares. The fol **`ActionDispatch::Static`** -* Used to serve static files. Disabled if `config.serve_static_files` is `false`. +* Used to serve static files from the public directory. Disabled if `config.public_file_server.enabled` is `false`. **`Rack::Lock`** * Sets `env["rack.multithread"]` flag to `false` and wraps the application within a Mutex. +**`ActionDispatch::Executor`** + +* Used for thread safe code reloading during development. + **`ActiveSupport::Cache::Strategy::LocalCache::Middleware`** * Used for memory caching. This cache is not thread safe. @@ -256,9 +240,17 @@ Much of Action Controller's functionality is implemented as Middlewares. The fol * Makes a unique `X-Request-Id` header available to the response and enables the `ActionDispatch::Request#request_id` method. +**`ActionDispatch::RemoteIp`** + +* Checks for IP spoofing attacks. + +**`Sprockets::Rails::QuietAssets`** + +* Suppresses logger output for asset requests. + **`Rails::Rack::Logger`** -* Notifies the logs that the request has began. After request is complete, flushes all the logs. +* Notifies the logs that the request has begun. After the request is complete, flushes all the logs. **`ActionDispatch::ShowExceptions`** @@ -268,10 +260,6 @@ Much of Action Controller's functionality is implemented as Middlewares. The fol * Responsible for logging exceptions and showing a debugging page in case the request is local. -**`ActionDispatch::RemoteIp`** - -* Checks for IP spoofing attacks. - **`ActionDispatch::Reloader`** * Provides prepare and cleanup callbacks, intended to assist with code reloading during development. @@ -284,14 +272,6 @@ Much of Action Controller's functionality is implemented as Middlewares. The fol * Checks pending migrations and raises `ActiveRecord::PendingMigrationError` if any migrations are pending. -**`ActiveRecord::ConnectionAdapters::ConnectionManagement`** - -* Cleans active connections after each request, unless the `rack.test` key in the request environment is set to `true`. - -**`ActiveRecord::QueryCache`** - -* Enables the Active Record query cache. - **`ActionDispatch::Cookies`** * Sets cookies for the request. @@ -304,17 +284,13 @@ Much of Action Controller's functionality is implemented as Middlewares. The fol * 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::Head`** * Converts HEAD requests to `GET` requests and serves them as so. **`Rack::ConditionalGet`** -* Adds support for "Conditional `GET`" so that server responds with nothing if page wasn't changed. +* Adds support for "Conditional `GET`" so that server responds with nothing if the page wasn't changed. **`Rack::ETag`** @@ -327,10 +303,8 @@ Resources ### Learning Rack -* [Official Rack Website](http://rack.github.io) +* [Official Rack Website](https://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) ### Understanding Middlewares diff --git a/guides/source/routing.md b/guides/source/routing.md index 7d0a3efbe7..efc0e32b56 100644 --- a/guides/source/routing.md +++ b/guides/source/routing.md @@ -7,18 +7,18 @@ This guide covers the user-facing features of Rails routing. After reading this guide, you will know: -* How to interpret the code in `routes.rb`. +* How to interpret the code in `config/routes.rb`. * How to construct your own routes, using either the preferred resourceful style or the `match` method. -* What parameters to expect an action to receive. +* How to declare route parameters, which are passed onto controller actions. * How to automatically create paths and URLs using route helpers. -* Advanced techniques such as constraints and Rack endpoints. +* Advanced techniques such as creating constraints and mounting Rack endpoints. -------------------------------------------------------------------------------- The Purpose of the Rails Router ------------------------------- -The Rails router recognizes URLs and dispatches them to a controller's action. It can also generate paths and URLs, avoiding the need to hardcode strings in your views. +The Rails router recognizes URLs and dispatches them to a controller's action, or to a Rack application. It can also generate paths and URLs, avoiding the need to hardcode strings in your views. ### Connecting URLs to Code @@ -47,7 +47,7 @@ get '/patients/:id', to: 'patients#show', as: 'patient' and your application contains this code in the controller: ```ruby -@patient = Patient.find(17) +@patient = Patient.find(params[:id]) ``` and this in the corresponding view: @@ -79,11 +79,13 @@ it asks the router to map it to a controller action. If the first matching route resources :photos ``` -Rails would dispatch that request to the `destroy` method on the `photos` controller with `{ id: '17' }` in `params`. +Rails would dispatch that request to the `destroy` action on the `photos` controller with `{ id: '17' }` in `params`. ### CRUD, Verbs, and Actions -In Rails, a resourceful route provides a mapping between HTTP verbs and URLs to controller actions. By convention, each action also maps to particular CRUD operations in a database. A single entry in the routing file, such as: +In Rails, a resourceful route provides a mapping between HTTP verbs and URLs to +controller actions. By convention, each action also maps to a specific CRUD +operation in a database. A single entry in the routing file, such as: ```ruby resources :photos @@ -140,16 +142,17 @@ 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: +Passing a `String` to `to:` will expect a `controller#action` format. When using a `Symbol`, the `to:` option should be replaced with `action:`. When using a `String` without a `#`, the `to:` option should be replaced with `controller:`: ```ruby -get 'profile', to: :show +get 'profile', action: :show, controller: 'users' ``` This resourceful route: ```ruby resource :geocoder +resolve('Geocoder') { [:geocoder] } ``` creates six different routes in your application, all mapping to the `Geocoders` controller: @@ -173,12 +176,6 @@ 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: @@ -248,11 +245,11 @@ TIP: _If you need to use a different controller namespace inside a `namespace` b It's common to have resources that are logically children of other resources. For example, suppose your application includes these models: ```ruby -class Magazine < ActiveRecord::Base +class Magazine < ApplicationRecord has_many :ads end -class Ad < ActiveRecord::Base +class Ad < ApplicationRecord belongs_to :magazine end ``` @@ -388,7 +385,7 @@ The comments resource here will have the following routes generated for it: ### Routing concerns -Routing Concerns allows you to declare common routes that can be reused inside other resources and routes. To define a concern: +Routing concerns allow you to declare common routes that can be reused inside other resources and routes. To define a concern: ```ruby concern :commentable do @@ -421,7 +418,7 @@ resources :articles do end ``` -Also you can use them in any place that you want inside the routes, for example in a scope or namespace call: +Also you can use them in any place that you want inside the routes, for example in a `scope` or `namespace` call: ```ruby namespace :articles do @@ -487,7 +484,7 @@ resources :photos do 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. +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 `photo_preview_url` and `photo_preview_path` helpers. 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 @@ -541,7 +538,7 @@ TIP: If you find yourself adding many extra actions to a resourceful route, it's Non-Resourceful Routes ---------------------- -In addition to resource routing, Rails has powerful support for routing arbitrary URLs to actions. Here, you don't get groups of routes automatically generated by resourceful routing. Instead, you set up each route within your application separately. +In addition to resource routing, Rails has powerful support for routing arbitrary URLs to actions. Here, you don't get groups of routes automatically generated by resourceful routing. Instead, you set up each route separately within your application. While you should usually use resourceful routing, there are still many places where the simpler routing is more appropriate. There's no need to try to shoehorn every last piece of your application into a resourceful framework if that's not a good fit. @@ -549,29 +546,23 @@ 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 this route: +When you set up a regular route, you supply a series of symbols that Rails maps to parts of an incoming HTTP request. For example, consider this route: ```ruby -get ':controller(/:action(/:id))' +get 'photos(/:id)', to: :display ``` -If an incoming request of `/photos/show/1` is processed by this route (because it hasn't matched any previous route in the file), then the result will be to invoke the `show` action of the `PhotosController`, and to make the final parameter `"1"` available as `params[:id]`. This route will also route the incoming request of `/photos` to `PhotosController#index`, since `:action` and `:id` are optional parameters, denoted by parentheses. +If an incoming request of `/photos/1` is processed by this route (because it hasn't matched any previous route in the file), then the result will be to invoke the `display` action of the `PhotosController`, and to make the final parameter `"1"` available as `params[:id]`. This route will also route the incoming request of `/photos` to `PhotosController#display`, since `:id` is an optional parameter, denoted by parentheses. ### Dynamic Segments -You can set up as many dynamic segments within a regular route as you like. Anything other than `:controller` or `:action` will be available to the action as part of `params`. If you set up this route: +You can set up as many dynamic segments within a regular route as you like. Any segment will be available to the action as part of `params`. If you set up this route: ```ruby -get ':controller/:action/:id/:user_id' +get 'photos/:id/:user_id', to: 'photos#show' ``` -An incoming path of `/photos/show/1/2` will be dispatched to the `show` action of the `PhotosController`. `params[:id]` will be `"1"`, and `params[:user_id]` will be `"2"`. - -NOTE: You can't use `:namespace` or `:module` with a `:controller` path segment. If you need to do this then use a constraint on :controller that matches the namespace you require. e.g: - -```ruby -get ':controller(/:action(/:id))', controller: /admin\/[^\/]+/ -``` +An incoming path of `/photos/1/2` will be dispatched to the `show` action of the `PhotosController`. `params[:id]` will be `"1"`, and `params[:user_id]` will be `"2"`. TIP: By default, dynamic segments don't accept dots - this is because the dot is used as a separator for formatted routes. If you need to use a dot within a dynamic segment, add a constraint that overrides this – for example, `id: /[^\/]+/` allows anything except a slash. @@ -580,38 +571,40 @@ TIP: By default, dynamic segments don't accept dots - this is because the dot is You can specify static segments when creating a route by not prepending a colon to a fragment: ```ruby -get ':controller/:action/:id/with_user/:user_id' +get 'photos/:id/with_user/:user_id', to: 'photos#show' ``` -This route would respond to paths such as `/photos/show/1/with_user/2`. In this case, `params` would be `{ controller: 'photos', action: 'show', id: '1', user_id: '2' }`. +This route would respond to paths such as `/photos/1/with_user/2`. In this case, `params` would be `{ controller: 'photos', action: 'show', id: '1', user_id: '2' }`. ### The Query String The `params` will also include any parameters from the query string. For example, with this route: ```ruby -get ':controller/:action/:id' +get 'photos/:id', to: 'photos#show' ``` -An incoming path of `/photos/show/1?user_id=2` will be dispatched to the `show` action of the `Photos` controller. `params` will be `{ controller: 'photos', action: 'show', id: '1', user_id: '2' }`. +An incoming path of `/photos/1?user_id=2` will be dispatched to the `show` action of the `Photos` controller. `params` will be `{ controller: 'photos', action: 'show', id: '1', user_id: '2' }`. ### Defining Defaults -You do not need to explicitly use the `:controller` and `:action` symbols within a route. You can supply them as defaults: +You can define defaults in a route by supplying a hash for the `:defaults` option. This even applies to parameters that you do not specify as dynamic segments. For example: ```ruby -get 'photos/:id', to: 'photos#show' +get 'photos/:id', to: 'photos#show', defaults: { format: 'jpg' } ``` -With this route, Rails will match an incoming path of `/photos/12` to the `show` action of `PhotosController`. +Rails would match `photos/12` to the `show` action of `PhotosController`, and set `params[:format]` to `"jpg"`. -You can also define other defaults in a route by supplying a hash for the `:defaults` option. This even applies to parameters that you do not specify as dynamic segments. For example: +You can also use `defaults` in a block format to define the defaults for multiple items: ```ruby -get 'photos/:id', to: 'photos#show', defaults: { format: 'jpg' } +defaults format: :json do + resources :photos +end ``` -Rails would match `photos/12` to the `show` action of `PhotosController`, and set `params[:format]` to `"jpg"`. +NOTE: You cannot override defaults via query parameters - this is for security reasons. The only defaults that can be overridden are dynamic segments via substitution in the URL path. ### Naming Routes @@ -647,7 +640,7 @@ 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. +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 @@ -700,6 +693,8 @@ 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. +NOTE: There is an exception for the `format` constraint: while it's a method on the Request object, it's also an implicit optional parameter on every path. Segment constraints take precedence and the `format` constraint is only applied as such when enforced through a hash. For example, `get 'foo', constraints: { format: 'json' }` will match `GET /foo` because the format is optional by default. However, you can [use a lambda](#advanced-constraints) like in `get 'foo', constraints: lambda { |req| req.format == :json }` and the route will only match explicit JSON requests. + ### 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: @@ -791,7 +786,11 @@ get '/stories/:name', to: redirect { |path_params, req| "/articles/#{path_params 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. +Please note that default 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. You can use the `:status` option to change the response status: + +```ruby +get '/stories/:name', to: redirect('/articles/%{name}', status: 302) +``` In all of these cases, if you don't provide the leading host (`http://www.example.com`), Rails will take those details from the current request. @@ -800,13 +799,28 @@ In all of these cases, if you don't provide the leading host (`http://www.exampl 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 +match '/application.js', to: MyRackApp, 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. +As long as `MyRackApp` 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, `'articles#index'` actually expands out to `ArticlesController.action(:index)`, which returns a valid Rack application. +If you specify a Rack application as the endpoint for a matcher, remember that +the route will be unchanged in the receiving application. With the following +route your Rack application should expect the route to be `/admin`: + +```ruby +match '/admin', to: AdminApp, via: :all +``` + +If you would prefer to have your Rack application receive requests at the root +path instead, use `mount`: + +```ruby +mount AdminApp, at: '/admin' +``` + ### Using `root` You can specify what Rails should route `'/'` to with the `root` method: @@ -838,6 +852,49 @@ You can specify unicode character routes directly. For example: get 'こんにちは', to: 'welcome#index' ``` +### Direct routes + +You can create custom URL helpers directly. For example: + +```ruby +direct :homepage do + "http://www.rubyonrails.org" +end + +# >> homepage_url +# => "http://www.rubyonrails.org" +``` + +The return value of the block must be a valid argument for the `url_for` method. So, you can pass a valid string URL, Hash, Array, an Active Model instance, or an Active Model class. + +```ruby +direct :commentable do |model| + [ model, anchor: model.dom_id ] +end + +direct :main do + { controller: 'pages', action: 'index', subdomain: 'www' } +end +``` + +### Using `resolve` + +The `resolve` method allows customizing polymorphic mapping of models. For example: + +``` ruby +resource :basket + +resolve("Basket") { [:basket] } +``` + +``` erb +<%= form_for @basket do |form| %> + <!-- basket form --> +<% end %> +``` + +This will generate the singular URL `/basket` instead of the usual `/baskets/:id`. + Customizing Resourceful Routes ------------------------------ @@ -1070,6 +1127,20 @@ edit_videos GET /videos/:identifier/edit(.:format) videos#edit Video.find_by(identifier: params[:identifier]) ``` +You can override `ActiveRecord::Base#to_param` of a related model to construct +a URL: + +```ruby +class Video < ApplicationRecord + def to_param + identifier + end +end + +video = Video.find_by(identifier: "Roman-Holiday") +edit_videos_path(video) # => "/videos/Roman-Holiday" +``` + Inspecting and Testing Routes ----------------------------- @@ -1077,16 +1148,16 @@ Rails offers facilities for inspecting and testing your routes. ### Listing Existing Routes -To get a complete list of the available routes in your application, visit `http://localhost:3000/rails/info/routes` in your browser while your server is running in the **development** environment. You can also execute the `rake routes` command in your terminal to produce the same output. +To get a complete list of the available routes in your application, visit `http://localhost:3000/rails/info/routes` in your browser while your server is running in the **development** environment. You can also execute the `rails routes` command in your terminal to produce the same output. -Both methods will list all of your routes, in the same order that they appear in `routes.rb`. For each route, you'll see: +Both methods will list all of your routes, in the same order that they appear in `config/routes.rb`. For each route, you'll see: * The route name (if any) * The HTTP verb used (if the route doesn't respond to all verbs) * The URL pattern to match * The routing parameters for the route -For example, here's a small section of the `rake routes` output for a RESTful route: +For example, here's a small section of the `rails routes` output for a RESTful route: ``` users GET /users(.:format) users#index @@ -1095,13 +1166,24 @@ For example, here's a small section of the `rake routes` output for a RESTful ro 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: +You can search through your routes with the grep option: -g. This outputs any routes that partially match the URL helper method name, the HTTP verb, or the URL path. -```bash -$ CONTROLLER=users bin/rake routes +``` +$ bin/rails routes -g new_comment +$ bin/rails routes -g POST +$ bin/rails routes -g admin +``` + +If you only want to see the routes that map to a specific controller, there's the -c option. + +``` +$ bin/rails routes -c users +$ bin/rails routes -c admin/users +$ bin/rails routes -c Comments +$ bin/rails routes -c Articles::CommentsController ``` -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. +TIP: You'll find that the output from `rails routes` is much more readable if you widen your terminal window until the output lines don't wrap. ### Testing Routes diff --git a/guides/source/ruby_on_rails_guides_guidelines.md b/guides/source/ruby_on_rails_guides_guidelines.md index 1323742488..de63e193f4 100644 --- a/guides/source/ruby_on_rails_guides_guidelines.md +++ b/guides/source/ruby_on_rails_guides_guidelines.md @@ -50,6 +50,48 @@ Use the same inline formatting as regular text: ##### The `:content_type` Option ``` +Linking to the API +------------------ + +Links to the API (`api.rubyonrails.org`) are processed by the guides generator in the following manner: + +Links that include a release tag are left untouched. For example + +``` +http://api.rubyonrails.org/v5.0.1/classes/ActiveRecord/Attributes/ClassMethods.html +``` + +is not modified. + +Please use these in release notes, since they should point to the corresponding version no matter the target being generated. + +If the link does not include a release tag and edge guides are being generated, the domain is replaced by `edgeapi.rubyonrails.org`. For example, + +``` +http://api.rubyonrails.org/classes/ActionDispatch/Response.html +``` + +becomes + +``` +http://edgeapi.rubyonrails.org/classes/ActionDispatch/Response.html +``` + +If the link does not include a release tag and release guides are being generated, the Rails version is injected. For example, if we are generating the guides for v5.1.0 the link + +``` +http://api.rubyonrails.org/classes/ActionDispatch/Response.html +``` + +becomes + +``` +http://api.rubyonrails.org/v5.1.0/classes/ActionDispatch/Response.html +``` + +Please don't link to `edgeapi.rubyonrails.org` manually. + + API Documentation Guidelines ---------------------------- @@ -64,7 +106,9 @@ The guides and the API should be coherent and consistent where appropriate. In p 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. +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 or later on your device. To install the latest version of Bundler, run `gem install bundler`. @@ -82,6 +126,8 @@ or bundle exec rake guides:generate:html ``` +Resulting HTML files can be found in the `./output` directory. + To process `my_guide.md` and nothing else use the `ONLY` environment variable: ``` @@ -93,8 +139,6 @@ By default, guides that have not been modified are not processed, so `ONLY` is r To force processing all the guides, pass `ALL=1`. -It is also recommended that you work with `WARNINGS=1`. This detects duplicate IDs and warns about broken internal links. - If you want to generate guides in a language other than English, you can keep them in a separate directory under `source` (eg. `source/es`) and use the `GUIDES_LANGUAGE` environment variable: ``` diff --git a/guides/source/security.md b/guides/source/security.md index e486edde31..916b1e32f8 100644 --- a/guides/source/security.md +++ b/guides/source/security.md @@ -1,7 +1,7 @@ **DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON http://guides.rubyonrails.org.** -Ruby on Rails Security Guide -============================ +Securing Rails Applications +=========================== This manual describes common security problems in web applications and how to avoid them with Rails. @@ -23,7 +23,7 @@ Web application frameworks are made to help developers build web applications. S 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). -The Gartner Group however estimates that 75% of attacks are at the web application layer, and found out "that out of 300 audited sites, 97% are vulnerable to attack". This is because web applications are relatively easy to attack, as they are simple to understand and manipulate, even by the lay person. +The Gartner Group, however, estimates that 75% of attacks are at the web application layer, and found out "that out of 300 audited sites, 97% are vulnerable to attack". This is because web applications are relatively easy to attack, as they are simple to understand and manipulate, even by the lay person. 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. @@ -41,28 +41,28 @@ NOTE: _HTTP is a stateless protocol. Sessions make it stateful._ Most applications need to keep track of certain state of a particular user. This could be the contents of a shopping basket or the user id of the currently logged in user. Without the idea of sessions, the user would have to identify, and probably authenticate, on every request. Rails will create a new session automatically if a new user accesses the application. It will load an existing session if the user has already used the application. -A session usually consists of a hash of values and a session id, usually a 32-character string, to identify the hash. Every cookie sent to the client's browser includes the session id. And the other way round: the browser will send it to the server on every request from the client. In Rails you can save and retrieve values using the session method: +A session usually consists of a hash of values and a session ID, usually a 32-character string, to identify the hash. Every cookie sent to the client's browser includes the session ID. And the other way round: the browser will send it to the server on every request from the client. In Rails you can save and retrieve values using the session method: ```ruby session[:user_id] = @current_user.id User.find(session[:user_id]) ``` -### Session id +### Session ID -NOTE: _The session id is a 32 byte long MD5 hash value._ +NOTE: _The session ID is a 32-character random hex string._ -A session id consists of the hash value of a random string. The random string is the current time, a random number between 0 and 1, the process id number of the Ruby interpreter (also basically a random number) and a constant string. Currently it is not feasible to brute-force Rails' session ids. To date MD5 is uncompromised, but there have been collisions, so it is theoretically possible to create another input text with the same hash value. But this has had no security impact to date. +The session ID is generated using `SecureRandom.hex` which generates a random hex string using platform specific methods (such as OpenSSL, /dev/urandom or Win32 CryptoAPI) for generating cryptographically secure random numbers. Currently it is not feasible to brute-force Rails' session IDs. ### Session Hijacking -WARNING: _Stealing a user's session id lets an attacker use the web application in the victim's name._ +WARNING: _Stealing a user's session ID lets an attacker use the web application in the victim's name._ -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. +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. 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. 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 @@ -85,32 +85,117 @@ This will also be a good idea, if you modify the structure of an object and old * _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 +### Encrypted Session Storage NOTE: _Rails provides several storage mechanisms for the session hashes. The most important is `ActionDispatch::Session::CookieStore`._ -Rails 2 introduced a new default session storage, CookieStore. CookieStore saves the session hash directly in a cookie on the client-side. The server retrieves the session hash from the cookie and eliminates the need for a session id. That will greatly increase the speed of the application, but it is a controversial storage option and you have to think about the security implications of it: +The `CookieStore` saves the session hash directly in a cookie on the +client-side. The server retrieves the session hash from the cookie and +eliminates the need for a session ID. That will greatly increase the +speed of the application, but it is a controversial storage option and +you have to think about the security implications and storage +limitations of it: + +* Cookies imply a strict size limit of 4kB. This is fine as you should + not store large amounts of data in a session anyway, as described + before. Storing the current user's database id in a session is common + practice. + +* Session cookies do not invalidate themselves and can be maliciously + reused. It may be a good idea to have your application invalidate old + session cookies using a stored timestamp. + +The `CookieStore` uses the +[encrypted](http://api.rubyonrails.org/classes/ActionDispatch/Cookies/ChainedCookieJars.html#method-i-encrypted) +cookie jar to provide a secure, encrypted location to store session +data. Cookie-based sessions thus provide both integrity as well as +confidentiality to their contents. The encryption key, as well as the +verification key used for +[signed](http://api.rubyonrails.org/classes/ActionDispatch/Cookies/ChainedCookieJars.html#method-i-signed) +cookies, is derived from the `secret_key_base` configuration value. + +As of Rails 5.2 encrypted cookies and sessions are protected using AES +GCM encryption. This form of encryption is a type of Authenticated +Encryption and couples authentication and encryption in single step +while also producing shorter ciphertexts as compared to other +algorithms previously used. The key for cookies encrypted with AES GCM +are derived using a salt value defined by the +`config.action_dispatch.authenticated_encrypted_cookie_salt` +configuration value. + +Prior to this version, encrypted cookies were secured using AES in CBC +mode with HMAC using SHA1 for authentication. The keys for this type of +encryption and for HMAC verification were derived via the salts defined +by `config.action_dispatch.encrypted_cookie_salt` and +`config.action_dispatch.encrypted_signed_cookie_salt` respectively. + +Prior to Rails version 4 in both versions 2 and 3, session cookies were +protected using only HMAC verification. As such, these session cookies +only provided integrity to their content because the actual session data +was stored in plaintext encoded as base64. This is how `signed` cookies +work in the current version of Rails. These kinds of cookies are still +useful for protecting the integrity of certain client-stored data and +information. + +__Do not use a trivial secret for the `secret_key_base`, i.e. a word +from a dictionary, or one which is shorter than 30 characters! Instead +use `rails secret` to generate secret keys!__ + +It is also important to use different salt values for encrypted and +signed cookies. Using the same value for different salt configuration +values may lead to the same derived key being used for different +security features which in turn may weaken the strength of the key. + +In test and development applications get a `secret_key_base` derived from the app name. Other environments must use a random key present in `config/credentials.yml.enc`, shown here in its decrypted state: + + secret_key_base: 492f... -* Cookies imply a strict size limit of 4kB. This is fine as you should not store large amounts of data in a session anyway, as described before. _Storing the current user's database id in a session is usually ok_. +If you have received an application where the secret was exposed (e.g. an application whose source was shared), strongly consider changing the secret. -* 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. +### Rotating Encrypted and Signed Cookies Configurations -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_. +Rotation is ideal for changing cookie configurations and ensuring old cookies +aren't immediately invalid. Your users then have a chance to visit your site, +get their cookie read with an old configuration and have it rewritten with the +new change. The rotation can then be removed once you're comfortable enough +users have had their chance to get their cookies upgraded. -`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.: +It's possible to rotate the ciphers and digests used for encrypted and signed cookies. - development: - secret_key_base: a75d... +For instance to change the digest used for signed cookies from SHA1 to SHA256, +you would first assign the new configuration value: - test: - secret_key_base: 492f... +```ruby +Rails.application.config.action_dispatch.signed_cookie_digest = "SHA256" +``` - production: - secret_key_base: <%= ENV["SECRET_KEY_BASE"] %> +Now add a rotation for the old SHA1 digest so existing cookies are +seamlessly upgraded to the new SHA256 digest. -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. +```ruby +Rails.application.config.action_dispatch.cookies_rotations.tap do |cookies| + cookies.rotate :signed, digest: "SHA1" +end +``` -If you have received an application where the secret was exposed (e.g. an application whose source was shared), strongly consider changing the secret. +Then any written signed cookies will be digested with SHA256. Old cookies +that were written with SHA1 can still be read, and if accessed will be written +with the new digest so they're upgraded and won't be invalid when you remove the +rotation. + +Once users with SHA1 digested signed cookies should no longer have a chance to +have their cookies rewritten, remove the rotation. + +While you can setup as many rotations as you'd like it's not common to have many +rotations going at any one time. + +For more details on key rotation with encrypted and signed messages as +well as the various options the `rotate` method accepts, please refer to +the +[MessageEncryptor API](http://api.rubyonrails.org/classes/ActiveSupport/MessageEncryptor.html) +and +[MessageVerifier API](http://api.rubyonrails.org/classes/ActiveSupport/MessageVerifier.html) +documentation. ### Replay Attacks for CookieStore Sessions @@ -124,22 +209,22 @@ It works like this: * 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). +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. Storing nonces in a database table would defeat the entire purpose of CookieStore (avoiding accessing the database). The best _solution against it is not to store this kind of data in a session, but in the database_. In this case store the credit in the database and the logged_in_user_id in the session. ### 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._ +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: +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: 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). +* 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. +* 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. @@ -153,7 +238,7 @@ 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 [Devise](https://rubygems.org/gems/devise) gem for user management, it will automatically expire sessions on sign in and sign out for you. If you roll your own, remember to expire the session after your sign in action (when the session is created). This will remove values from the session, therefore _you will 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. @@ -161,10 +246,10 @@ Another countermeasure is to _save user-specific properties in the session_, ver 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. +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. ```ruby -class Session < ActiveRecord::Base +class Session < ApplicationRecord def self.sweep(time = 1.hour) if time.is_a?(String) time = time.split.inject { |count, unit| count.to_i.send(unit) } @@ -175,7 +260,7 @@ class Session < ActiveRecord::Base end ``` -The section about session fixation introduced the problem of maintained sessions. An attacker maintaining a session every five minutes can keep the session alive forever, although you are expiring sessions. A simple solution for this would be to add a created_at column to the sessions table. Now you can delete sessions that were created a long time ago. Use this line in the sweep method above: +The section about session fixation introduced the problem of maintained sessions. An attacker maintaining a session every five minutes can keep the session alive forever, although you are expiring sessions. A simple solution for this would be to add a `created_at` column to the sessions table. Now you can delete sessions that were created a long time ago. Use this line in the sweep method above: ```ruby delete_all "updated_at < '#{time.ago.to_s(:db)}' OR @@ -189,13 +274,12 @@ This attack method works by including malicious code or a link in a page that ac  -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: +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 if the request comes from a site of a different domain, it will also send the cookie. 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 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. 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. @@ -206,7 +290,7 @@ CSRF appears very rarely in CVE (Common Vulnerabilities and Exposures) - less th NOTE: _First, as is required by the W3C, use GET and POST appropriately. Secondly, a security token in non-GET requests will protect your application from CSRF._ -The HTTP protocol basically provides two main types of requests - GET and POST (and more, but they are not supported by most browsers). The World Wide Web Consortium (W3C) provides a checklist for choosing HTTP GET or POST: +The HTTP protocol basically provides two main types of requests - GET and POST (DELETE, PUT, and PATCH should be used like POST). The World Wide Web Consortium (W3C) provides a checklist for choosing HTTP GET or POST: **Use GET if:** @@ -218,9 +302,9 @@ 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 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. +If your web application is RESTful, you might be used to additional HTTP verbs, such as PATCH, PUT or DELETE. Some legacy web browsers, however, do not support them - only GET and POST. Rails uses a hidden `_method` field to handle these cases. -_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. +_POST requests can be sent automatically, too_. In this example, the link www.harmless.com is shown as the destination in the browser's status bar. But it has actually dynamically created a new form that sends a POST request. ```html <a href="http://www.harmless.com/" onclick=" @@ -239,9 +323,11 @@ 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, 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. +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 must disallow cross-site `<script>` tags. Ajax requests, however, obey the browser's same-origin policy (only your own site is allowed to initiate `XmlHttpRequest`) so we can safely allow them to return JavaScript responses. -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: +Note: We can't distinguish a `<script>` tag's origin—whether it's a tag on your own site or on some other malicious site—so we must block all `<script>` across the board, even if it's actually a safe same-origin script served from your own site. In these cases, explicitly skip CSRF protection on actions that serve JavaScript meant for a `<script>` tag. + +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 with: :exception @@ -249,13 +335,12 @@ protect_from_forgery with: :exception 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 +NOTE: By default, Rails includes an [unobtrusive scripting adapter](https://github.com/rails/rails/blob/master/actionview/app/assets/javascripts), +which adds a header called `X-CSRF-Token` with the security token on every non-GET +Ajax call. 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: @@ -279,7 +364,7 @@ Another class of security vulnerabilities surrounds the use of redirection and f 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: +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: ```ruby def legacy @@ -293,7 +378,7 @@ This will redirect the user to the main action if they tried to access a legacy http://www.example.com/site/legacy?param1=xy¶m2=23&host=www.attacker.com ``` -If it is at the end of the URL it will hardly be noticed and redirects the user to the attacker.com host. A simple countermeasure would be to _include only the expected parameters in a legacy action_ (again a whitelist approach, as opposed to removing unexpected parameters). _And if you redirect to an URL, check it with a whitelist or a regular expression_. +If it is at the end of the URL it will hardly be noticed and redirects the user to the attacker.com host. A simple countermeasure would be to _include only the expected parameters in a legacy action_ (again a whitelist approach, as opposed to removing unexpected parameters). _And if you redirect to a URL, check it with a whitelist or a regular expression_. #### Self-contained XSS @@ -349,7 +434,7 @@ 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_: ```ruby -basename = File.expand_path(File.join(File.dirname(__FILE__), '../../files')) +basename = File.expand_path('../../files', __dir__) filename = File.expand_path(File.join(basename, @file.public_filename)) raise if basename != File.expand_path(File.join(File.dirname(filename), '../../../')) @@ -369,13 +454,13 @@ In 2007 there was the first tailor-made trojan which stole information from an I 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. +Refer to the Injection section for countermeasures against XSS. **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/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. +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 the user, but it also contained an image tag that resulted in an 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 their credentials.
+Another example changed Google Adsense's e-mail address and password. If the victim was logged into Google Adsense, the administration interface for Google advertisement campaigns, an attacker could change the credentials of the victim.
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. @@ -398,7 +483,7 @@ 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 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): +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 a 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 @@ -445,18 +530,20 @@ However, the attacker may also take over the account by changing the e-mail addr #### 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 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_. +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 an 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 they are 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 registration forms from attackers and comment forms from automatic spam bots by asking the user to type the letters of a distorted image. This is the positive CAPTCHA, but there is also the negative CAPTCHA. 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](https://github.com/ambethia/recaptcha/) is also a Rails plug-in with the same name as the API. +A popular positive CAPTCHA API is [reCAPTCHA](https://developers.google.com/recaptcha/) 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 they are human, but reveal that a spam robot is a bot. +The problem with CAPTCHAs is that they have a negative impact on the user experience. Additionally, some visually impaired users have found certain kinds of distorted CAPTCHAs difficult to read. Still, positive CAPTCHAs are one of the best methods to prevent all kinds of bots from submitting forms. + +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. -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. +Note that negative CAPTCHAs are only effective against dumb bots and won't suffice to protect critical applications from targeted bots. Still, the negative and positive CAPTCHAs can be combined to increase the performance, e.g., if the "honeypot" field is not empty (bot detected), you won't need to verify the positive CAPTCHA, which would require an HTTPS request to Google ReCaptcha before computing the response. Here are some ideas how to hide honeypot fields by JavaScript and/or CSS: @@ -484,6 +571,8 @@ By default, Rails logs all requests being made to the web application. But log f config.filter_parameters << :password ``` +NOTE: Provided parameters will be filtered out by partial matching regular expression. Rails adds default `:password` in the appropriate initializer (`initializers/filter_parameter_logging.rb`) and cares about typical application parameters `password` and `password_confirmation`. + ### Good Passwords 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._ @@ -555,7 +644,7 @@ This is alright for some web applications, but certainly not if the user is not Depending on your web application, there will be many more parameters the user can tamper with. As a rule of thumb, _no user input data is secure, until proven otherwise, and every parameter from the user is potentially manipulated_. -Don't be fooled by security by obfuscation and JavaScript security. The Web Developer Toolbar for Mozilla Firefox lets you review and change every form's hidden fields. _JavaScript can be used to validate user input data, but certainly not to prevent attackers from sending malicious requests with unexpected values_. The Live Http Headers plugin for Mozilla Firefox logs every request and may repeat and change them. That is an easy way to bypass any JavaScript validations. And there are even client-side proxies that allow you to intercept any request and response from and to the Internet. +Don't be fooled by security by obfuscation and JavaScript security. Developer tools let you review and change every form's hidden fields. _JavaScript can be used to validate user input data, but certainly not to prevent attackers from sending malicious requests with unexpected values_. The Firebug addon for Mozilla Firefox logs every request and may repeat and change them. That is an easy way to bypass any JavaScript validations. And there are even client-side proxies that allow you to intercept any request and response from and to the Internet. Injection --------- @@ -570,7 +659,7 @@ NOTE: _When sanitizing, protecting or verifying something, prefer whitelists ove 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_: -* Use before_action only: [...] instead of except: [...]. This way you don't forget to turn it off for newly added actions. +* Use before_action except: [...] instead of only: [...] for security-related actions. This way you don't forget to enable security checks for newly added actions. * Allow <strong> instead of removing <script> against Cross-Site Scripting (XSS). See below for details. * Don't try to correct user input by blacklists: * This will make the attack work: "<sc<script>ript>".gsub("<script>", "") @@ -603,7 +692,7 @@ The two dashes start a comment ignoring everything after it. So the query return 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]}'") +User.find_by("login = '#{params[:name]}' AND password = '#{params[:password]}'") ``` If an attacker enters ' OR '1'='1 as the name, and ' OR '2'>'1 as the password, the resulting SQL query will be: @@ -665,13 +754,11 @@ 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 or client-site proxies make it easy to change requests. There are also other attack vectors like banner advertisements. 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. -During the second half of 2007, there were 88 vulnerabilities reported in Mozilla browsers, 22 in Safari, 18 in IE, and 12 in Opera. 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) also documented 239 browser plug-in vulnerabilities in the last six months of 2007. [Mpack](http://pandalabs.pandasecurity.com/mpack-uncovered/) is a very active and up-to-date attack framework which exploits these vulnerabilities. For criminal hackers, it is very attractive to exploit an SQL-Injection vulnerability in a web application framework and insert malicious code in every textual table column. In April 2008 more than 510,000 sites were hacked like this, among them the British government, United Nations, and many more high targets. - -A relatively new, and unusual, form of entry points are banner advertisements. In earlier 2008, malicious code appeared in banner ads on popular sites, such as MySpace and Excite, according to [Trend Micro](http://blog.trendmicro.com/myspace-excite-and-blick-serve-up-malicious-banner-ads/). +During the second half of 2007, there were 88 vulnerabilities reported in Mozilla browsers, 22 in Safari, 18 in IE, and 12 in Opera. 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) also documented 239 browser plug-in vulnerabilities in the last six months of 2007. [Mpack](http://pandalabs.pandasecurity.com/mpack-uncovered/) is a very active and up-to-date attack framework which exploits these vulnerabilities. For criminal hackers, it is very attractive to exploit an SQL-Injection vulnerability in a web application framework and insert malicious code in every textual table column. In April 2008 more than 510,000 sites were hacked like this, among them the British government, United Nations, and many more high profile targets. #### HTML/JavaScript Injection @@ -710,7 +797,7 @@ The log files on www.attacker.com will read like this: GET http://www.attacker.com/_app_session=836c1c25278e5b321d6bea4f19cb57e2 ``` -You can mitigate these attacks (in the obvious way) by adding the [httpOnly](http://dev.rubyonrails.org/ticket/8895) flag to cookies, so that document.cookie may not be read by JavaScript. Http only cookies can be used from IE v6.SP1, Firefox v2.0.0.5 and Opera 9.5. Safari is still considering, it ignores the option. But other, older browsers (such as WebTV and IE 5.5 on Mac) can actually cause the page to fail to load. Be warned that cookies [will still be visible using Ajax](http://ha.ckers.org/blog/20070719/firefox-implements-httponly-and-is-vulnerable-to-xmlhttprequest/), though. +You can mitigate these attacks (in the obvious way) by adding the **httpOnly** flag to cookies, so that document.cookie may not be read by JavaScript. HTTP only cookies can be used from IE v6.SP1, Firefox v2.0.0.5, Opera 9.5, Safari 4 and Chrome 1.0.154 onwards. But other, older browsers (such as WebTV and IE 5.5 on Mac) can actually cause the page to fail to load. Be warned that cookies [will still be visible using Ajax](https://www.owasp.org/index.php/HTTPOnly#Browsers_Supporting_HttpOnly), though. ##### Defacement @@ -752,7 +839,7 @@ 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 gem. 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 &, ", <, and > by their uninterpreted representations in HTML (`&`, `"`, `<`, and `>`). ##### Obfuscation and Encoding Injection @@ -777,21 +864,19 @@ The following is an excerpt from the [Js.Yamanner@m](http://www.symantec.com/sec var IDList = ''; var CRumb = ''; function makeRequest(url, Func, Method,Param) { ... ``` -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. +The worms exploit a hole in Yahoo's HTML/JavaScript filter, which usually filters all targets 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/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. -The MySpace Samy worm will be discussed in the CSS Injection section. - ### CSS Injection INFO: _CSS Injection is actually JavaScript injection, because some browsers (IE, some versions of Safari and others) allow JavaScript in CSS. Think twice about allowing custom CSS in your web application._ -CSS Injection is explained best by a well-known worm, the [MySpace Samy worm](http://namb.la/popular/tech.html). This worm automatically sent a friend request to Samy (the attacker) simply by visiting his profile. Within several hours he had over 1 million friend requests, but it creates too much traffic on MySpace, so that the site goes offline. The following is a technical explanation of the worm. +CSS Injection is explained best by the well-known [MySpace Samy worm](https://samy.pl/popular/tech.html). This worm automatically sent a friend request to Samy (the attacker) simply by visiting his profile. Within several hours he had over 1 million friend requests, which created so much traffic that MySpace went offline. The following is a technical explanation of that worm. -MySpace blocks many tags, however it allows CSS. So the worm's author put JavaScript into CSS like this: +MySpace blocked many tags, but allowed CSS. So the worm's author put JavaScript into CSS like this: ```html <div style="background:url('javascript:alert(1)')"> @@ -815,7 +900,7 @@ The next problem was MySpace filtering the word "javascript", so the author used <div id="mycode" expr="alert('hah!')" style="background:url('java↵
script:eval(document.all.mycode.expr)')"> ``` -Another problem for the worm's author were CSRF security tokens. Without them he couldn't send a friend request over POST. He got around it by sending a GET to the page right before adding a user and parsing the result for the CSRF token. +Another problem for the worm's author was the [CSRF security tokens](#cross-site-request-forgery-csrf). Without them he couldn't send a friend request over POST. He got around it by sending a GET to the page right before adding a user and parsing the result for the CSRF token. In the end, he got a 4 KB worm, which he injected into his profile page. @@ -923,7 +1008,7 @@ HTTP/1.1 200 OK [Second New response created by attacker begins] Content-Type: text/html -<html><font color=red>hey</font></html> [Arbitary malicious input is +<html><font color=red>hey</font></html> [Arbitrary malicious input is Keep-Alive: timeout=15, max=100 shown as the redirected page] Connection: Keep-Alive Transfer-Encoding: chunked @@ -957,7 +1042,7 @@ 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 +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: @@ -969,7 +1054,7 @@ request: | `{ "person": [null, null, ...] }` | `{ :person => [] }` | | `{ "person": ["foo", null] }` | `{ :person => ["foo"] }` | -It is possible to return to old behaviour and disable `deep_munge` configuring +It is possible to return to old behavior and disable `deep_munge` configuring your application if you are aware of the risk and know how to handle it: ```ruby @@ -1006,29 +1091,53 @@ config.action_dispatch.default_headers.clear 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. -* X-XSS-Protection -_'1; mode=block' in Rails by default_ - use XSS Auditor and block page if XSS attack is detected. Set it to '0;' if you want to switch XSS Auditor off(useful if response contents scripts from request parameters) -* 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://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 -[Used to control if the browser is allowed to only access a site over a secure connection](http://en.wikipedia.org/wiki/HTTP_Strict_Transport_Security) +* **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. +* **X-XSS-Protection:** _'1; mode=block' in Rails by default_ - use XSS Auditor and block page if XSS attack is detected. Set it to '0;' if you want to switch XSS Auditor off(useful if response contents scripts from request parameters) +* **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://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:** [Used to control if the browser is allowed to only access a site over a secure connection](https://en.wikipedia.org/wiki/HTTP_Strict_Transport_Security) 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/secrets.yml`. You may want to further restrict access, using environment-specific versions of these files and any others that may contain sensitive information. +### Custom credentials + +Rails generates a `config/credentials.yml.enc` to store third-party credentials +within the repo. This is only viable because Rails encrypts the file with a master +key that's generated into a version control ignored `config/master.key` — Rails +will also look for that key in `ENV["RAILS_MASTER_KEY"]`. Rails also requires the +key to boot in production, so the credentials can be read. + +To edit stored credentials use `bin/rails credentials:edit`. + +By default, this file contains the application's +`secret_key_base`, but it could also be used to store other credentials such as +access keys for external APIs. + +The credentials added to this file are accessible via `Rails.application.credentials`. +For example, with the following decrypted `config/credentials.yml.enc`: + + secret_key_base: 3b7cd727ee24e8444053437c36cc66c3 + some_api_key: SOMEKEY + +`Rails.application.credentials.some_api_key` returns `SOMEKEY` in any environment. + +If you want an exception to be raised when some key is blank, use the bang +version: + +```ruby +Rails.application.credentials.some_api_key! # => raises KeyError: :some_api_key is blank +``` + Additional Resources -------------------- The security landscape shifts and it is important to keep up to date, because missing a new vulnerability can be catastrophic. You can find additional resources about (Rails) security here: -* Subscribe to the Rails security [mailing list](http://groups.google.com/group/rubyonrails-security) -* [Keep up to date on the other application layers](http://secunia.com/) (they have a weekly newsletter, too) -* A [good security blog](http://ha.ckers.org/blog/) including the [Cross-Site scripting Cheat Sheet](http://ha.ckers.org/xss.html) +* Subscribe to the Rails security [mailing list](https://groups.google.com/forum/#!forum/rubyonrails-security). +* [Brakeman - Rails Security Scanner](https://brakemanscanner.org/) - To perform static security analysis for Rails applications. +* [Keep up to date on the other application layers](http://secunia.com/) (they have a weekly newsletter, too). +* A [good security blog](https://www.owasp.org) including the [Cross-Site scripting Cheat Sheet](https://www.owasp.org/index.php/DOM_based_XSS_Prevention_Cheat_Sheet). diff --git a/guides/source/testing.md b/guides/source/testing.md index 752ef48b16..b82ccebe7c 100644 --- a/guides/source/testing.md +++ b/guides/source/testing.md @@ -1,14 +1,14 @@ **DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON http://guides.rubyonrails.org.** -A Guide to Testing Rails Applications -===================================== +Testing Rails Applications +========================== This guide covers built-in mechanisms in Rails for testing your application. After reading this guide, you will know: * Rails testing terminology. -* How to write unit, functional, and integration tests for your application. +* How to write unit, functional, integration, and system tests for your application. * Other popular testing approaches and plugins. -------------------------------------------------------------------------------- @@ -18,22 +18,14 @@ Why Write Tests for your Rails Applications? Rails makes it super easy to write your tests. It starts by producing skeleton test code while you are creating your models and controllers. -By simply running your Rails tests you can ensure your code adheres to the desired functionality even after some major code refactoring. +By running your Rails tests you can ensure your code adheres to the desired functionality even after some major code refactoring. Rails tests can also simulate browser requests and thus you can test your application's response without having to test it through your browser. Introduction to Testing ----------------------- -Testing support was woven into the Rails fabric from the beginning. It wasn't an "oh! let's bolt on support for running tests because they're new and cool" epiphany. Just about every Rails application interacts heavily with a database and, as a result, your tests will need a database to interact with as well. To write efficient tests, you'll need to understand how to set up this database and populate it with sample data. - -### The Test Environment - -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. 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`. +Testing support was woven into the Rails fabric from the beginning. It wasn't an "oh! let's bolt on support for running tests because they're new and cool" epiphany. ### Rails Sets up for Testing from the Word Go @@ -41,138 +33,44 @@ Rails creates a `test` directory for you as soon as you create a Rails project u ```bash $ ls -F test -controllers/ helpers/ mailers/ test_helper.rb -fixtures/ integration/ models/ -``` - -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` 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. -You can find comprehensive documentation in the [Fixtures API documentation](http://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html). - -#### What Are Fixtures? - -_Fixtures_ is a fancy word for sample data. Fixtures allow you to populate your testing database with predefined data before your tests run. Fixtures are database independent and written in YAML. There is one file per model. - -You'll find fixtures under your `test/fixtures` directory. When you run `rails generate model` to create a new model, Rails automatically creates fixture stubs in this directory. - -#### YAML - -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! -david: - name: David Heinemeier Hansson - birthday: 1979-10-15 - profession: Systems development - -steve: - 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 line. 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 - -ERB allows you to embed Ruby code within templates. The YAML fixture format is pre-processed with ERB when Rails loads fixtures. This allows you to use Ruby to help you generate some sample data. For example, the following code generates a thousand users: - -```erb -<% 1000.times do |n| %> -user_<%= n %>: - username: <%= "user#{n}" %> - email: <%= "user#{n}@example.com" %> -<% end %> +controllers/ helpers/ mailers/ system/ test_helper.rb +fixtures/ integration/ models/ application_system_test_case.rb ``` -#### Fixtures in Action +The `helpers`, `mailers`, and `models` directories are meant to hold tests for view helpers, mailers, and models, respectively. The `controllers` directory is meant to hold tests for controllers, routes, and views. The `integration` directory is meant to hold tests for interactions between controllers. -Rails by default automatically loads all fixtures from the `test/fixtures` directory for your models and controllers test. Loading involves three steps: +The system test directory holds system tests, which are used for full browser +testing of your application. System tests allow you to test your application +the way your users experience it and help you test your JavaScript as well. +System tests inherit from Capybara and perform in browser tests for your +application. -1. Remove any existing data from the table corresponding to the fixture -2. Load the fixture data into the table -3. 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 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 -users(:david) +Fixtures are a way of organizing test data; they reside in the `fixtures` directory. -# this will return the property for david called id -users(:david).id +A `jobs` directory will also be created when an associated test is first generated. -# one can also access methods available on the User class -email(david.partner.email, david.location_tonight) -``` +The `test_helper.rb` file holds the default configuration for your tests. -### Rake Tasks for Running your Tests +The `application_system_test_case.rb` holds the default configuration for your system +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 | +### The Test Environment -We will cover each of types Rails tests listed above in this guide. +By default, every Rails application has three environments: development, test, and production. -Model Testing ------------------------- +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`. -In Rails, unit tests are what you write to test your models. +NOTE: Your tests are run under `RAILS_ENV=test`. -For this guide we will be using the application we built in the [Getting Started with Rails](getting_started.html) guide. +### Rails meets Minitest -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: +If you remember, we used the `rails generate model` command in the +[Getting Started with Rails](getting_started.html) guide. We created our first +model, and among other things it created test stubs in the `test` directory: ```bash -$ bin/rails generate scaffold article title:string body:text +$ bin/rails generate model article title:string body:text ... create app/models/article.rb create test/models/article_test.rb @@ -198,13 +96,13 @@ A line by line examination of this file will help get you oriented to Rails test require 'test_helper' ``` -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. +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 our tests. ```ruby class ArticleTest < ActiveSupport::TestCase ``` -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. +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, we'll see some of the methods it gives us. 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. @@ -225,7 +123,7 @@ def test_the_truth end ``` -However only the `test` macro allows a more readable test name. You can still use regular method definitions though. +Although you can still use regular method definitions, using the `test` macro allows for a more readable test name. 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. @@ -242,48 +140,7 @@ An assertion is a line of code that evaluates an object (or expression) for expe * does this line of code throw an exception? * is the user's password greater than 5 characters? -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. - -### Maintaining the test database schema - -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. - -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 `rake test` command. - -```bash -$ bin/rake test test/models/article_test.rb -. - -Finished tests in 0.009262s, 107.9680 tests/s, 107.9680 assertions/s. - -1 tests, 1 assertions, 0 failures, 0 errors, 0 skips -``` - -This will run all test methods from the test case. - -You can also run a particular test method from the test case by running the test and providing the `test method name`. - -```bash -$ bin/rake test test/models/article_test.rb test_the_truth -. - -Finished tests in 0.009064s, 110.3266 tests/s, 110.3266 assertions/s. - -1 tests, 1 assertions, 0 failures, 0 errors, 0 skips -``` - -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. +Every test may contain one or more assertions, with no restriction as to how many assertions are allowed. Only when all the assertions are successful will the test pass. #### Your first failing test @@ -296,22 +153,32 @@ test "should not save article without title" do end ``` -Let us run this newly added test. +Let us run this newly added test (where `6` is the number of line where the test is defined). ```bash -$ bin/rake test test/models/article_test.rb test_should_not_save_article_without_title +$ bin/rails test test/models/article_test.rb:6 +Run options: --seed 44656 + +# Running: + F -Finished tests in 0.044632s, 22.4054 tests/s, 22.4054 assertions/s. +Failure: +ArticleTest#test_should_not_save_article_without_title [/path/to/blog/test/models/article_test.rb:6]: +Expected true to be nil or false - 1) Failure: -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, 0 skips +bin/rails test test/models/article_test.rb:6 + + + +Finished in 0.023918s, 41.8090 runs/s, 41.8090 assertions/s. + +1 runs, 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: +In the output, `F` denotes a failure. You can see the corresponding trace shown under `Failure` along with the name of the failing test. The next few lines contain the stack trace followed by a message that 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 article without title" do @@ -323,15 +190,15 @@ end Running this test shows the friendlier assertion message: ```bash - 1) Failure: -test_should_not_save_article_without_title(ArticleTest) [test/models/article_test.rb:6]: +Failure: +ArticleTest#test_should_not_save_article_without_title [/path/to/blog/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 Article < ActiveRecord::Base +class Article < ApplicationRecord validates :title, presence: true end ``` @@ -339,12 +206,16 @@ end Now the test should pass. Let us verify by running the test again: ```bash -$ bin/rake test test/models/article_test.rb test_should_not_save_article_without_title +$ bin/rails test test/models/article_test.rb:6 +Run options: --seed 31252 + +# Running: + . -Finished tests in 0.047721s, 20.9551 tests/s, 20.9551 assertions/s. +Finished in 0.027476s, 36.3952 runs/s, 36.3952 assertions/s. -1 tests, 1 assertions, 0 failures, 0 errors, 0 skips +1 runs, 1 assertions, 0 failures, 0 errors, 0 skips ``` Now, if you noticed, we first wrote a test which fails for a desired @@ -368,17 +239,26 @@ end Now you can see even more output in the console from running the tests: ```bash -$ bin/rake test test/models/article_test.rb test_should_report_error -E +$ bin/rails test test/models/article_test.rb +Run options: --seed 1808 + +# Running: + +.E + +Error: +ArticleTest#test_should_report_error: +NameError: undefined local variable or method 'some_undefined_variable' for #<ArticleTest:0x007fee3aa71798> + test/models/article_test.rb:11:in 'block in <class:ArticleTest>' -Finished tests in 0.030974s, 32.2851 tests/s, 0.0000 assertions/s. - 1) 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>' +bin/rails test test/models/article_test.rb:9 -1 tests, 0 assertions, 0 failures, 1 errors, 0 skips + + +Finished in 0.040609s, 49.2500 runs/s, 24.6250 assertions/s. + +2 runs, 1 assertions, 0 failures, 1 errors, 0 skips ``` Notice the 'E' in the output. It denotes a test with error. @@ -386,18 +266,17 @@ 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 random order. The -[`config.active_support.test_order` option](http://edgeguides.rubyonrails.org/configuring.html#configuring-active-support) +[`config.active_support.test_order` option](configuring.html#configuring-active-support) can be used to configure test order. 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: +backtrace. Set the `-b` (or `--backtrace`) argument to enable this behavior: ```bash -$ BACKTRACE=1 bin/rake test test/models/article_test.rb +$ bin/rails test -b test/models/article_test.rb ``` If we want this test to pass we can modify it to use `assert_raises` like so: @@ -417,9 +296,49 @@ This test should now pass. 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 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) +Here's an extract of the assertions you can use with +[`Minitest`](https://github.com/seattlerb/minitest), 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. + +| Assertion | Purpose | +| ---------------------------------------------------------------- | ------- | +| `assert( test, [msg] )` | Ensures that `test` is true.| +| `assert_not( test, [msg] )` | Ensures that `test` is false.| +| `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 false.| +| `assert_nil( obj, [msg] )` | Ensures that `obj.nil?` is true.| +| `assert_not_nil( obj, [msg] )` | Ensures that `obj.nil?` is false.| +| `assert_empty( obj, [msg] )` | Ensures that `obj` is `empty?`.| +| `assert_not_empty( obj, [msg] )` | Ensures that `obj` is not `empty?`.| +| `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_includes( collection, obj, [msg] )` | Ensures that `obj` is in `collection`.| +| `assert_not_includes( collection, obj, [msg] )` | Ensures that `obj` is not in `collection`.| +| `assert_in_delta( expected, actual, [delta], [msg] )` | Ensures that the numbers `expected` and `actual` are within `delta` of each other.| +| `assert_not_in_delta( expected, actual, [delta], [msg] )` | Ensures that the numbers `expected` and `actual` are not within `delta` of each other.| +| `assert_in_epsilon ( expected, actual, [epsilon], [msg] )` | Ensures that the numbers `expected` and `actual` have a relative error less than `epsilon`.| +| `assert_not_in_epsilon ( expected, actual, [epsilon], [msg] )` | Ensures that the numbers `expected` and `actual` don't have a relative error less than `epsilon`.| +| `assert_throws( symbol, [msg] ) { block }` | Ensures that the given block throws the symbol.| +| `assert_raises( exception1, exception2, ... ) { block }` | Ensures that the given block raises one of the given exceptions.| +| `assert_instance_of( class, obj, [msg] )` | Ensures that `obj` is an instance of `class`.| +| `assert_not_instance_of( class, obj, [msg] )` | Ensures that `obj` is not an instance of `class`.| +| `assert_kind_of( class, obj, [msg] )` | Ensures that `obj` is an instance of `class` or is descending from it.| +| `assert_not_kind_of( class, obj, [msg] )` | Ensures that `obj` is not an instance of `class` and is not descending from it.| +| `assert_respond_to( obj, symbol, [msg] )` | Ensures that `obj` responds to `symbol`.| +| `assert_not_respond_to( obj, symbol, [msg] )` | Ensures that `obj` does not respond to `symbol`.| +| `assert_operator( obj1, operator, [obj2], [msg] )` | Ensures that `obj1.operator(obj2)` is true.| +| `assert_not_operator( obj1, operator, [obj2], [msg] )` | Ensures that `obj1.operator(obj2)` is false.| +| `assert_predicate ( obj, predicate, [msg] )` | Ensures that `obj.predicate` is true, e.g. `assert_predicate str, :empty?`| +| `assert_not_predicate ( obj, predicate, [msg] )` | Ensures that `obj.predicate` is false, e.g. `assert_not_predicate str, :empty?`| +| `flunk( [msg] )` | Ensures failure. This is useful to explicitly mark a test that isn't finished yet.| + +The above are a subset of assertions that minitest supports. For an exhaustive & +more up-to-date list, please check +[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. @@ -431,37 +350,566 @@ Rails adds some custom assertions of its own to the `minitest` framework: | Assertion | Purpose | | --------------------------------------------------------------------------------- | ------- | -| `assert_difference(expressions, difference = 1, message = nil) {...}` | Test numeric difference between the return value of an expression as a result of what is evaluated in the yielded block.| -| `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. 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.| +| [`assert_difference(expressions, difference = 1, message = nil) {...}`](http://api.rubyonrails.org/classes/ActiveSupport/Testing/Assertions.html#method-i-assert_difference) | Test numeric difference between the return value of an expression as a result of what is evaluated in the yielded block.| +| [`assert_no_difference(expressions, message = nil, &block)`](http://api.rubyonrails.org/classes/ActiveSupport/Testing/Assertions.html#method-i-assert_no_difference) | Asserts that the numeric result of evaluating an expression is not changed before and after invoking the passed in block.| +| [`assert_changes(expressions, message = nil, from:, to:, &block)`](http://api.rubyonrails.org/classes/ActiveSupport/Testing/Assertions.html#method-i-assert_changes) | Test that the result of evaluating an expression is changed after invoking the passed in block.| +| [`assert_no_changes(expressions, message = nil, &block)`](http://api.rubyonrails.org/classes/ActiveSupport/Testing/Assertions.html#method-i-assert_no_changes) | Test the result of evaluating an expression is not changed after invoking the passed in block.| +| [`assert_nothing_raised { block }`](http://api.rubyonrails.org/classes/ActiveSupport/Testing/Assertions.html#method-i-assert_nothing_raised) | Ensures that the given block doesn't raise any exceptions.| +| [`assert_recognizes(expected_options, path, extras={}, message=nil)`](http://api.rubyonrails.org/classes/ActionDispatch/Assertions/RoutingAssertions.html#method-i-assert_recognizes) | 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)`](http://api.rubyonrails.org/classes/ActionDispatch/Assertions/RoutingAssertions.html#method-i-assert_generates) | 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)`](http://api.rubyonrails.org/classes/ActionDispatch/Assertions/ResponseAssertions.html#method-i-assert_response) | 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)`](http://api.rubyonrails.org/classes/ActionDispatch/Assertions/ResponseAssertions.html#method-i-assert_redirected_to) | Asserts 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`.| You'll see the usage of some of these assertions in the next chapter. -### A Brief Note About Minitest +### A Brief Note About Test Cases 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` -* `ActiveJob::TestCase` +* [`ActiveSupport::TestCase`](http://api.rubyonrails.org/classes/ActiveSupport/TestCase.html) +* [`ActionMailer::TestCase`](http://api.rubyonrails.org/classes/ActionMailer/TestCase.html) +* [`ActionView::TestCase`](http://api.rubyonrails.org/classes/ActionView/TestCase.html) +* [`ActiveJob::TestCase`](http://api.rubyonrails.org/classes/ActiveJob/TestCase.html) +* [`ActionDispatch::IntegrationTest`](http://api.rubyonrails.org/classes/ActionDispatch/IntegrationTest.html) +* [`ActionDispatch::SystemTestCase`](http://api.rubyonrails.org/classes/ActionDispatch/SystemTestCase.html) +* [`Rails::Generators::TestCase`](http://api.rubyonrails.org/classes/Rails/Generators/TestCase.html) 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) +NOTE: For more information on `Minitest`, refer to [its +documentation](http://docs.seattlerb.org/minitest). + +### The Rails Test Runner + +We can run all of our tests at once by using the `bin/rails test` command. + +Or we can run a single test file by passing the `bin/rails test` command the filename containing the test cases. + +```bash +$ bin/rails test test/models/article_test.rb +Run options: --seed 1559 + +# Running: + +.. + +Finished in 0.027034s, 73.9810 runs/s, 110.9715 assertions/s. + +2 runs, 3 assertions, 0 failures, 0 errors, 0 skips +``` + +This will run all test methods from the test case. + +You can also run a particular test method from the test case by providing the +`-n` or `--name` flag and the test's method name. + +```bash +$ bin/rails test test/models/article_test.rb -n test_the_truth +Run options: -n test_the_truth --seed 43583 + +# Running: + +. + +Finished tests in 0.009064s, 110.3266 tests/s, 110.3266 assertions/s. + +1 tests, 1 assertions, 0 failures, 0 errors, 0 skips +``` + +You can also run a test at a specific line by providing the line number. + +```bash +$ bin/rails test test/models/article_test.rb:6 # run specific test and line +``` + +You can also run an entire directory of tests by providing the path to the directory. + +```bash +$ bin/rails test test/controllers # run all tests from specific directory +``` + +The test runner also provides a lot of other features like failing fast, deferring test output +at the end of test run and so on. Check the documentation of the test runner as follows: + +```bash +$ bin/rails test -h +minitest options: + -h, --help Display this help. + -s, --seed SEED Sets random seed. Also via env. Eg: SEED=n rake + -v, --verbose Verbose. Show progress processing files. + -n, --name PATTERN Filter run on /regexp/ or string. + --exclude PATTERN Exclude /regexp/ or string from run. + +Known extensions: rails, pride + +Usage: bin/rails test [options] [files or directories] +You can run a single test by appending a line number to a filename: + + bin/rails test test/models/user_test.rb:27 + +You can run multiple files and directories at the same time: + + bin/rails test test/controllers test/integration/login_test.rb + +By default test failures and errors are reported inline during a run. + +Rails options: + -w, --warnings Run with Ruby warnings enabled + -e, --environment Run tests in the ENV environment + -b, --backtrace Show the complete backtrace + -d, --defer-output Output test failures and errors after the test run + -f, --fail-fast Abort test run on first failure or error + -c, --[no-]color Enable color in the output +``` + +The Test Database +----------------- + +Just about every Rails application interacts heavily with a database and, as a result, your tests will need a database to interact with as well. To write efficient tests, you'll need to understand how to set up this database and populate it with sample data. + +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. This way your tests can mangle test data with confidence, without worrying about the data in the development or production databases. + + +### Maintaining the test database schema + +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. 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/rails db:migrate`) will +bring the schema up to date. + +NOTE: If there were modifications to existing migrations, the test database needs to +be rebuilt. This can be done by executing `bin/rails db:test:prepare`. + +### 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. +You can find comprehensive documentation in the [Fixtures API documentation](http://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html). + +#### What Are Fixtures? + +_Fixtures_ is a fancy word for sample data. Fixtures allow you to populate your testing database with predefined data before your tests run. Fixtures are database independent and written in YAML. There is one file per model. + +NOTE: Fixtures are not designed to create every object that your tests need, and are best managed when only used for default data that can be applied to the common case. + +You'll find fixtures under your `test/fixtures` directory. When you run `rails generate model` to create a new model, Rails automatically creates fixture stubs in this directory. + +#### YAML + +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! +david: + name: David Heinemeier Hansson + birthday: 1979-10-15 + profession: Systems development + +steve: + 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 line. 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 +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 +first: + title: Welcome to Rails! + body: Hello world! + category: about +``` + +Notice the `category` key of the `first` 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 can use the fixture name instead of specifying 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 + +ERB allows you to embed Ruby code within templates. The YAML fixture format is pre-processed with ERB when Rails loads fixtures. This allows you to use Ruby to help you generate some sample data. For example, the following code generates a thousand users: + +```erb +<% 1000.times do |n| %> +user_<%= n %>: + username: <%= "user#{n}" %> + email: <%= "user#{n}@example.com" %> +<% end %> +``` + +#### Fixtures in Action + +Rails automatically loads all fixtures from the `test/fixtures` directory by +default. Loading involves three steps: + +1. Remove any existing data from the table corresponding to the fixture +2. Load the fixture data into the table +3. 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 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 +users(:david) + +# this will return the property for david called id +users(:david).id + +# one can also access methods available on the User class +david = users(:david) +david.call(david.partner) +``` + +To get multiple fixtures at once, you can pass in a list of fixture names. For example: + +```ruby +# this will return an array containing the fixtures david and steve +users(:david, :steve) +``` + + +Model Testing +------------- + +Model tests are used to test the various models of your application. + +Rails model tests are stored under the `test/models` directory. Rails provides +a generator to create a model test skeleton for you. + +```bash +$ bin/rails generate test_unit:model article title:string body:text +create test/models/article_test.rb +create test/fixtures/articles.yml +``` + +Model tests don't have their own superclass like `ActionMailer::TestCase` instead they inherit from [`ActiveSupport::TestCase`](http://api.rubyonrails.org/classes/ActiveSupport/TestCase.html). + +System Testing +-------------- + +System tests allow you to test user interactions with your application, running tests +in either a real or a headless browser. System tests uses Capybara under the hood. + +For creating Rails system tests, you use the `test/system` directory in your +application. Rails provides a generator to create a system test skeleton for you. + +```bash +$ bin/rails generate system_test users + invoke test_unit + create test/system/users_test.rb +``` + +Here's what a freshly generated system test looks like: + +```ruby +require "application_system_test_case" + +class UsersTest < ApplicationSystemTestCase + # test "visiting the index" do + # visit users_url + # + # assert_selector "h1", text: "Users" + # end +end +``` + +By default, system tests are run with the Selenium driver, using the Chrome +browser, and a screen size of 1400x1400. The next section explains how to +change the default settings. + +### Changing the default settings + +Rails makes changing the default settings for system tests very simple. All +the setup is abstracted away so you can focus on writing your tests. + +When you generate a new application or scaffold, an `application_system_test_case.rb` file +is created in the test directory. This is where all the configuration for your +system tests should live. + +If you want to change the default settings you can change what the system +tests are "driven by". Say you want to change the driver from Selenium to +Poltergeist. First add the `poltergeist` gem to your `Gemfile`. Then in your +`application_system_test_case.rb` file do the following: + +```ruby +require "test_helper" +require "capybara/poltergeist" + +class ApplicationSystemTestCase < ActionDispatch::SystemTestCase + driven_by :poltergeist +end +``` + +The driver name is a required argument for `driven_by`. The optional arguments +that can be passed to `driven_by` are `:using` for the browser (this will only +be used by Selenium), `:screen_size` to change the size of the screen for +screenshots, and `:options` which can be used to set options supported by the +driver. + +```ruby +require "test_helper" + +class ApplicationSystemTestCase < ActionDispatch::SystemTestCase + driven_by :selenium, using: :firefox +end +``` + +If you want to use a headless browser, you could use Headless Chrome or Headless Firefox by adding +`headless_chrome` or `headless_firefox` in the `:using` argument. + +```ruby +require "test_helper" + +class ApplicationSystemTestCase < ActionDispatch::SystemTestCase + driven_by :selenium, using: :headless_chrome +end +``` + +If your Capybara configuration requires more setup than provided by Rails, this +additional configuration could be added into the `application_system_test_case.rb` +file. + +Please see [Capybara's documentation](https://github.com/teamcapybara/capybara#setup) +for additional settings. + +### Screenshot Helper + +The `ScreenshotHelper` is a helper designed to capture screenshots of your tests. +This can be helpful for viewing the browser at the point a test failed, or +to view screenshots later for debugging. + +Two methods are provided: `take_screenshot` and `take_failed_screenshot`. +`take_failed_screenshot` is automatically included in `after_teardown` inside +Rails. + +The `take_screenshot` helper method can be included anywhere in your tests to +take a screenshot of the browser. + +### Implementing a system test + +Now we're going to add a system test to our blog application. We'll demonstrate +writing a system test by visiting the index page and creating a new blog article. + +If you used the scaffold generator, a system test skeleton was automatically +created for you. If you didn't use the scaffold generator, start by creating a +system test skeleton. + +```bash +$ bin/rails generate system_test articles +``` + +It should have created a test file placeholder for us. With the output of the +previous command you should see: + +```bash + invoke test_unit + create test/system/articles_test.rb +``` + +Now let's open that file and write our first assertion: + +```ruby +require "application_system_test_case" + +class ArticlesTest < ApplicationSystemTestCase + test "viewing the index" do + visit articles_path + assert_selector "h1", text: "Articles" + end +end +``` + +The test should see that there is an `h1` on the articles index page and pass. + +Run the system tests. + +```bash +bin/rails test:system +``` + +NOTE: By default, running `bin/rails test` won't run your system tests. +Make sure to run `bin/rails test:system` to actually run them. + +#### Creating articles system test + +Now let's test the flow for creating a new article in our blog. + +```ruby +test "creating an article" do + visit articles_path + + click_on "New Article" + + fill_in "Title", with: "Creating an Article" + fill_in "Body", with: "Created this article successfully!" + + click_on "Create Article" + + assert_text "Creating an Article" +end +``` + +The first step is to call `visit articles_path`. This will take the test to the +articles index page. + +Then the `click_on "New Article"` will find the "New Article" button on the +index page. This will redirect the browser to `/articles/new`. + +Then the test will fill in the title and body of the article with the specified +text. Once the fields are filled in, "Create Article" is clicked on which will +send a POST request to create the new article in the database. + +We will be redirected back to the articles index page and there we assert +that the text from the new article's title is on the articles index page. + +#### Taking it further + +The beauty of system testing is that it is similar to integration testing in +that it tests the user's interaction with your controller, model, and view, but +system testing is much more robust and actually tests your application as if +a real user were using it. Going forward, you can test anything that the user +themselves would do in your application such as commenting, deleting articles, +publishing draft articles, etc. + +Integration Testing +------------------- + +Integration tests are used to test how various parts of your application interact. They are generally used to test important workflows within our application. + +For creating Rails integration tests, we use the `test/integration` directory for our application. Rails provides a generator to create an integration test skeleton for us. + +```bash +$ bin/rails generate integration_test user_flows + exists test/integration/ + create test/integration/user_flows_test.rb +``` + +Here's what a freshly generated integration test looks like: + +```ruby +require 'test_helper' + +class UserFlowsTest < ActionDispatch::IntegrationTest + # test "the truth" do + # assert true + # end +end +``` + +Here the test is inheriting from `ActionDispatch::IntegrationTest`. This makes some additional helpers available for us to use in our integration tests. + +### Helpers Available for Integration Tests + +In addition to the standard testing helpers, inheriting from `ActionDispatch::IntegrationTest` comes with some additional helpers available when writing integration tests. Let's get briefly introduced to the three categories of helpers we get to choose from. + +For dealing with the integration test runner, see [`ActionDispatch::Integration::Runner`](http://api.rubyonrails.org/classes/ActionDispatch/Integration/Runner.html). + +When performing requests, we will have [`ActionDispatch::Integration::RequestHelpers`](http://api.rubyonrails.org/classes/ActionDispatch/Integration/RequestHelpers.html) available for our use. + +If we need to modify the session, or state of our integration test, take a look at [`ActionDispatch::Integration::Session`](http://api.rubyonrails.org/classes/ActionDispatch/Integration/Session.html) to help. + +### Implementing an integration test + +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. + +We'll start by generating our integration test skeleton: + +```bash +$ bin/rails generate integration_test blog_flow +``` + +It should have created a test file placeholder for us. With the output of the +previous command we should see: + +```bash + invoke test_unit + create test/integration/blog_flow_test.rb +``` + +Now let's open that file and write our first assertion: + +```ruby +require 'test_helper' + +class BlogFlowTest < ActionDispatch::IntegrationTest + test "can see the welcome page" do + get "/" + assert_select "h1", "Welcome#index" + end +end +``` + +We will take a look at `assert_select` to query the resulting HTML of a request in the "Testing Views" section below. It is used for testing the response of our request by asserting the presence of key HTML elements and their content. + +When we visit our root path, we should see `welcome/index.html.erb` rendered for the view. So this assertion should pass. + +#### Creating articles integration + +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 + + post "/articles", + params: { article: { title: "can create", body: "article successfully." } } + assert_response :redirect + follow_redirect! + assert_response :success + assert_select "p", "Title:\n can create" +end +``` + +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. + +After this we make a post request to the `:create` action of our Articles controller: + +```ruby +post "/articles", + params: { 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 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 editing comments. Integration tests are a great place to experiment with all kinds of use-cases for our applications. + Functional Tests for Your Controllers ------------------------------------- -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. +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 are 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 +### What to include in your Functional Tests You should test for things such as: @@ -471,46 +919,70 @@ 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 `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. +The easiest way to see functional tests in action is to generate a controller using the scaffold generator: + +```bash +$ bin/rails generate scaffold_controller article title:string body:text +... +create app/controllers/articles_controller.rb +... +invoke test_unit +create test/controllers/articles_controller_test.rb +... +``` + +This will generate the controller code and tests for an `Article` resource. +You can take a look at the file `articles_controller_test.rb` in the `test/controllers` directory. + +If you already have a controller and just want to generate the test scaffold code for +each of the seven default actions, you can use the following command: + +```bash +$ bin/rails generate test_unit:scaffold article +... +invoke test_unit +create test/controllers/articles_controller_test.rb +... +``` -Let me take you through one such test, `test_should_get_index` from the file `articles_controller_test.rb`. +Let's take a look at one such test, `test_should_get_index` from the file `articles_controller_test.rb`. ```ruby -class ArticlesControllerTest < ActionController::TestCase +# articles_controller_test.rb +class ArticlesControllerTest < ActionDispatch::IntegrationTest test "should get index" do - get :index + get articles_url 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 `articles` instance variable. - -The `get` method kicks off the web request and populates the results into the response. It accepts 4 arguments: +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 the right response body has been generated. -* The action of the controller you are requesting. - This can be in the form of a string or a symbol. +The `get` method kicks off the web request and populates the results into the `@response`. It can accept up to 6 arguments: +* The URI of the controller action you are requesting. + This can be in the form of a string or a route helper (e.g. `articles_url`). * `params`: option with a hash of request parameters to pass into the action (e.g. query string parameters or article variables). +* `headers`: for setting the headers that will be passed with the request. +* `env`: for customizing the request environment as needed. +* `xhr`: whether the request is Ajax request or not. Can be set to true for marking the request as Ajax. +* `as`: for encoding the request with different content type. Supports `:json` by default. -* `session`: option with a hash of session variables to pass along with the request. +All of these keyword arguments are optional. -* `flash`: option with a hash of flash values. - -All the keyword arguments are optional. - -Example: Calling the `:show` action, passing an `id` of 12 as the `params` and setting a `user_id` of 5 in the session: +Example: Calling the `:show` action, passing an `id` of 12 as the `params` and setting `HTTP_REFERER` header: ```ruby -get(:show, params: { 'id' => "12" }, session: { 'user_id' => 5 }) +get article_url, params: { id: 12 }, headers: { "HTTP_REFERER" => "http://example.com/home" } ``` -Another example: Calling the `:view` action, passing an `id` of 12 as the `params`, this time with no session, but with a flash message. +Another example: Calling the `:update` action, passing an `id` of 12 as the `params` as an Ajax request. ```ruby -get(:view, params: { 'id' => '12' }, flash: { 'message' => 'booya!' }) +patch article_url, params: { id: 12 }, xhr: true ``` 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. @@ -520,15 +992,22 @@ Let us modify `test_should_create_article` test in `articles_controller_test.rb` ```ruby test "should create article" do assert_difference('Article.count') do - post :create, params: { article: { title: 'Some title' } } + post articles_url, params: { article: { body: 'Rails is awesome!', title: 'Hello Rails' } } end - assert_redirected_to article_path(assigns(:article)) + assert_redirected_to article_path(Article.last) end ``` Now you can try running all the tests and they should pass. +NOTE: If you followed the steps in the Basic Authentication section, you'll need to add the following to the `setup` block to get all the tests passing: + +```ruby +request.headers['Authorization'] = ActionController::HttpAuthentication::Basic. + encode_credentials('dhh', 'secret') +``` + ### Available Request Types for Functional Tests If you're familiar with the HTTP protocol, you'll know that `get` is a type of request. There are 6 request types supported in Rails functional tests: @@ -547,105 +1026,73 @@ NOTE: Functional tests do not verify whether the specified request type is accep ### Testing XHR (AJAX) requests To test AJAX requests, you can specify the `xhr: true` option to `get`, `post`, -`patch`, `put`, and `delete` methods: +`patch`, `put`, and `delete` methods. For example: ```ruby -test "ajax request responds with no layout" do - get :show, params: { id: articles(:first).id }, xhr: true +test "ajax request" do + article = articles(:one) + get article_url(article), xhr: true - assert_template :index - assert_template layout: nil + assert_equal 'hello world', @response.body + assert_equal "text/javascript", @response.content_type end ``` -### The Four Hashes of the Apocalypse +### The Three Hashes of the Apocalypse -After a request has been made and processed, you will have 4 Hash objects ready for use: +After a request has been made and processed, you will have 3 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. -* `flash` - Any objects living in the flash. -* `session` - Any object living in session variables. +* `cookies` - Any cookies that are set +* `flash` - Any objects living in the flash +* `session` - Any object living in session variables -As is the case with normal Hash objects, you can access the values by referencing the keys by string. You can also reference them by symbol name, except for `assigns`. For example: +As is the case with normal Hash objects, you can access the values by referencing the keys by string. You can also reference them by symbol name. For example: ```ruby flash["gordon"] flash[:gordon] session["shmession"] session[:shmession] cookies["are_good_for_u"] cookies[:are_good_for_u] - -# Because you can't use assigns[:something] for historical reasons: -assigns["something"] assigns(:something) ``` ### Instance Variables Available -You also have access to three instance variables in your functional tests: +You also have access to three instance variables in your functional tests, after a request is made: * `@controller` - The controller processing the request * `@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: ```ruby -test "index should render correct template and layout" do - get :index - assert_template :index - assert_template layout: "layouts/application" +class ArticlesControllerTest < ActionDispatch::IntegrationTest + test "should get index" do + get articles_url - # You can also pass a regular expression. - assert_template layout: /layouts\/application/ + assert_equal "index", @controller.action_name + assert_equal "application/x-www-form-urlencoded", @request.media_type + assert_match "Articles", @response.body + end end ``` -NOTE: You cannot test for template and layout at the same time, with a single call to `assert_template`. - -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. - -#### Asserting Partials - -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. +### Setting Headers and CGI variables -Remember, we added the "_form" partial to our new Article view? Let's write an assertion for that in the `:new` action now: +[HTTP headers](https://tools.ietf.org/search/rfc2616#section-5.3) +and +[CGI variables](https://tools.ietf.org/search/rfc3875#section-4.1) +can be passed as headers: ```ruby -test "new should render correct layout" do - get :new - assert_template layout: "layouts/application", partial: "_form" -end -``` +# setting an HTTP Header +get articles_url, headers: { "Content-Type": "text/plain" } # simulate the request with custom header -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. +# setting a CGI variable +get articles_url, headers: { "HTTP_REFERER": "http://example.com/home" } # simulate the request with custom env variable +``` ### Testing `flash` notices -If you remember from earlier one of the Four Hashes of the Apocalypse was `flash`. +If you remember from earlier, one of the Three Hashes of the Apocalypse was `flash`. We want to add a `flash` message to our blog application whenever someone successfully creates a new Article. @@ -655,10 +1102,10 @@ Let's start by adding this assertion to our `test_should_create_article` test: ```ruby test "should create article" do assert_difference('Article.count') do - post :create, params: { article: { title: 'Some title' } } + post article_url, params: { article: { title: 'Some title' } } end - assert_redirected_to article_path(assigns(:article)) + assert_redirected_to article_path(Article.last) assert_equal 'Article was successfully created.', flash[:notice] end ``` @@ -666,7 +1113,7 @@ end If we run our test now, we should see a failure: ```bash -$ bin/rake test test/controllers/articles_controller_test.rb test_should_create_article +$ bin/rails test test/controllers/articles_controller_test.rb -n test_should_create_article Run options: -n test_should_create_article --seed 32266 # Running: @@ -676,7 +1123,7 @@ F Finished in 0.114870s, 8.7055 runs/s, 34.8220 assertions/s. 1) Failure: -ArticlesControllerTest#test_should_create_article [/Users/zzak/code/bench/sharedapp/test/controllers/articles_controller_test.rb:16]: +ArticlesControllerTest#test_should_create_article [/test/controllers/articles_controller_test.rb:16]: --- expected +++ actual @@ -1 +1 @@ @@ -704,7 +1151,7 @@ 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 +$ bin/rails test test/controllers/articles_controller_test.rb -n test_should_create_article Run options: -n test_should_create_article --seed 18981 # Running: @@ -725,12 +1172,12 @@ Let's write a test for the `:show` action: ```ruby test "should show article" do article = articles(:one) - get :show, params: { id: article.id } + get article_url(article) assert_response :success end ``` -Remember from our discussion earlier on fixtures the `articles()` method will give us access to our Articles fixtures. +Remember from our discussion earlier on fixtures, the `articles()` method will give us access to our Articles fixtures. How about deleting an existing Article? @@ -738,7 +1185,7 @@ How about deleting an existing Article? test "should destroy article" do article = articles(:one) assert_difference('Article.count', -1) do - delete :destroy, params: { id: article.id } + delete article_url(article) end assert_redirected_to articles_path @@ -750,47 +1197,56 @@ We can also add a test for updating an existing Article. ```ruby test "should update article" do article = articles(:one) - patch :update, params: { id: article.id, article: { title: "updated" } } - assert_redirected_to article_path(assigns(:article)) + + patch article_url(article), params: { article: { title: "updated" } } + + assert_redirected_to article_path(article) + # Reload association to fetch updated data and assert that title is updated. + article.reload + assert_equal "updated", article.title end ``` 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`. -Our test should now look something like this, disregard the other tests we're leaving them out for brevity. +Our test should now look something as what follows. Disregard the other tests for now, we're leaving them out for brevity. ```ruby require 'test_helper' -class ArticlesControllerTest < ActionController::TestCase +class ArticlesControllerTest < ActionDispatch::IntegrationTest # called before every single test - def setup + setup do @article = articles(:one) end # called after every single test - def teardown + teardown do # when controller is using cache it may be a good idea to reset it afterwards Rails.cache.clear end test "should show article" do # Reuse the @article instance variable from setup - get :show, params: { id: @article.id } + get article_url(@article) assert_response :success end test "should destroy article" do assert_difference('Article.count', -1) do - delete :destroy, params: { id: @article.id } + delete article_url(@article) end assert_redirected_to articles_path end test "should update article" do - patch :update, params: { id: @article.id, article: { title: "updated" } } - assert_redirected_to article_path(assigns(:article)) + patch article_url(@article), params: { article: { title: "updated" } } + + assert_redirected_to article_path(@article) + # Reload association to fetch updated data and assert that title is updated. + @article.reload + assert_equal "updated", @article.title end end ``` @@ -803,15 +1259,15 @@ To avoid code duplication, you can add your own test helpers. Sign in helper can be a good example: ```ruby -test/test_helper.rb +# test/test_helper.rb module SignInHelper - def sign_in(user) - session[:user_id] = user.id + def sign_in_as(user) + post sign_in_url(email: user.email, password: user.password) end end -class ActionController::TestCase +class ActionDispatch::IntegrationTest include SignInHelper end ``` @@ -819,15 +1275,14 @@ end ```ruby require 'test_helper' -class ProfileControllerTest < ActionController::TestCase +class ProfileControllerTest < ActionDispatch::IntegrationTest test "should show profile" do # helper is now reusable from any controller test case - sign_in users(:david) + sign_in_as users(:david) - get :show + get profile_url assert_response :success - assert_equal users(:david), assigns(:user) end end ``` @@ -835,40 +1290,16 @@ end Testing Routes -------------- -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: - -```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 -``` - -I've added this file here `test/controllers/articles_routes_test.rb` and if we run the test we should see: +Like everything else in your Rails application, you can test your routes. Route tests reside in `test/controllers/` or are part of controller tests. -```bash -$ bin/rake test test/controllers/articles_routes_test.rb - -# Running: - -.. - -Finished in 0.069381s, 28.8263 runs/s, 86.4790 assertions/s. - -2 runs, 6 assertions, 0 failures, 0 errors, 0 skips -``` +NOTE: If your application has complex routes, Rails provides a number of useful helpers to test them. 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). Testing Views ------------- -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. +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. Like route tests, view tests reside in `test/controllers/` or are part of controller tests. The `assert_select` method allows you to query HTML elements of the response by using a simple yet powerful syntax. There are two forms of `assert_select`: @@ -909,7 +1340,7 @@ assert_select "ol" do end ``` -This assertion is quite powerful. For more advanced usage, refer to its [documentation](http://www.rubydoc.info/github/rails/rails-dom-testing). +This assertion is quite powerful. For more advanced usage, refer to its [documentation](https://github.com/rails/rails-dom-testing/blob/master/lib/rails/dom/testing/assertions/selector_assertions.rb). #### Additional View-Based Assertions @@ -932,29 +1363,31 @@ end Testing Helpers --------------- +A helper is just a simple module where you can define methods which are +available into your views. + 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. -A helper test looks like so: +Given we have the following helper: ```ruby -require 'test_helper' - -class UserHelperTest < ActionView::TestCase +module UserHelper + def link_to_user(user) + link_to "#{user.first_name} #{user.last_name}", user + end end ``` -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: +We can test the output of this method like this: ```ruby class UserHelperTest < ActionView::TestCase - include UserHelper + test "should return the user's full name" do + user = users(:david) - test "should return the user name" do - # ... + assert_dom_equal %{<a href="/user/#{user.id}">David Heinemeier Hansson</a>}, link_to_user(user) end end ``` @@ -962,120 +1395,6 @@ end Moreover, since the test class extends from `ActionView::TestCase`, you have access to Rails' helper methods such as `link_to` or `pluralize`. -Integration Testing -------------------- - -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. - -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. - -```bash -$ bin/rails generate integration_test user_flows - exists test/integration/ - create test/integration/user_flows_test.rb -``` - -Here's what a freshly-generated integration test looks like: - -```ruby -require 'test_helper' - -class UserFlowsTest < ActionDispatch::IntegrationTest - # test "the truth" do - # assert true - # end -end -``` - -Inheriting from `ActionDispatch::IntegrationTest` comes with some advantages. This makes available some additional helpers to use in your integration tests. - -### Helpers Available for Integration Tests - -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. - -For dealing with the integration test runner, see [`ActionDispatch::Integration::Runner`](http://api.rubyonrails.org/classes/ActionDispatch/Integration/Runner.html). - -When performing requests, you will have [`ActionDispatch::Integration::RequestHelpers`](http://api.rubyonrails.org/classes/ActionDispatch/Integration/RequestHelpers.html) available for your use. - -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. - -### Implementing an integration test - -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. - -We'll start by generating our integration test skeleton: - -```bash -$ bin/rails generate integration_test blog_flow -``` - -It should have created a test file placeholder for us, with the output of the previous command you should see: - -```bash - invoke test_unit - create test/integration/blog_flow_test.rb -``` - -Now let's open that file and write our first assertion: - -```ruby -require 'test_helper' - -class BlogFlowTest < ActionDispatch::IntegrationTest - test "can see the welcome page" do - get "/" - assert_select "h1", "Welcome#index" - end -end -``` - -If you remember from earlier in the "Testing Views" section we covered `assert_select` to query the resulting HTML of a request. - -When visit our root path, we should see `welcome/index.html.erb` rendered for the view. So this assertion should pass. - -#### Creating articles integration - -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", - params: { 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 -``` - -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. - -After this we make a post request to the `:create` action of our Articles controller: - -```ruby -post "/articles", - params: { 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 -------------------- @@ -1103,7 +1422,7 @@ In order to test that your mailer is working as expected, you can use unit tests For the purposes of unit testing a mailer, fixtures are used to provide an example of how the output _should_ look. Because these are example emails, and not Active Record data like the other fixtures, they are kept in their own subdirectory apart from the other fixtures. The name of the directory within `test/fixtures` directly corresponds to the name of the mailer. So, for a mailer named `UserMailer`, the fixtures should reside in `test/fixtures/user_mailer` directory. -When you generated your mailer, the generator creates stub fixtures for each of the mailers actions. If you didn't use the generator you'll have to make those files yourself. +If you generated your mailer, the generator does not create stub fixtures for the mailers actions. You'll have to create those files yourself as described above. #### The Basic Test Case @@ -1114,10 +1433,13 @@ require 'test_helper' class UserMailerTest < ActionMailer::TestCase test "invite" do + # Create the email and store it for further assertions + email = UserMailer.create_invite('me@example.com', + 'friend@example.com', Time.now) + # Send the email, then test that it got queued assert_emails 1 do - email = UserMailer.create_invite('me@example.com', - 'friend@example.com', Time.now).deliver_now + email.deliver_now end # Test the body of the sent email contains what we expect it to @@ -1134,6 +1456,10 @@ 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. +NOTE: `email.body.to_s` is present when there's only one (HTML or text) part present. +If the mailer provides both, you can test your fixture against specific parts +with `email.text_part.body.to_s` or `email.html_part.body.to_s`. + Here's the content of the `invite` fixture: ``` @@ -1152,9 +1478,9 @@ testing) but instead it will be appended to an array (`ActionMailer::Base.deliveries`). 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` +`ActionMailer::TestCase` and `ActionDispatch::IntegrationTest` tests. +If you want to have a clean slate outside these test cases, you can reset it +manually with: `ActionMailer::Base.deliveries.clear` ### Functional Testing @@ -1163,16 +1489,16 @@ Functional testing for mailers involves more than just checking that the email b ```ruby require 'test_helper' -class UserControllerTest < ActionController::TestCase +class UserControllerTest < ActionDispatch::IntegrationTest test "invite friend" do assert_difference 'ActionMailer::Base.deliveries.size', +1 do - post :invite_friend, params: { email: 'friend@example.com' } + post invite_friend_url, params: { email: 'friend@example.com' } end invite_email = ActionMailer::Base.deliveries.last 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.to_s) + assert_match(/Hi friend@example\.com/, invite_email.body.to_s) end end ``` @@ -1181,7 +1507,7 @@ 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) +you'll need to test both, the jobs themselves (their behavior when they get enqueued) and that other entities correctly enqueue them. ### A Basic Test Case @@ -1200,7 +1526,7 @@ class BillingJobTest < ActiveJob::TestCase end ``` -This test is pretty simple and only asserts that the job get the work done +This test is pretty simple and only asserts that the job got the work done as expected. By default, `ActiveJob::TestCase` will set the queue adapter to `:test` so that @@ -1229,15 +1555,25 @@ class ProductTest < ActiveJob::TestCase end ``` -Other Testing Approaches ------------------------- +Additional Testing Resources +---------------------------- + +### Testing Time-Dependent Code -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: +Rails provides built-in helper methods that enable you to assert that your time-sensitive code works as expected. + +Here is an example using the [`travel_to`](http://api.rubyonrails.org/classes/ActiveSupport/Testing/TimeHelpers.html#method-i-travel_to) helper: + +```ruby +# Lets say that a user is eligible for gifting a month after they register. +user = User.create(name: 'Gaurish', activation_date: Date.new(2004, 10, 24)) +assert_not user.applicable_for_gifting? +travel_to Date.new(2004, 11, 24) do + assert_equal Date.new(2004, 10, 24), user.activation_date # inside the `travel_to` block `Date.current` is mocked + assert user.applicable_for_gifting? +end +assert_equal Date.new(2004, 10, 24), user.activation_date # The change was visible only inside the `travel_to` block. +``` -* [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. -* [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 +Please see [`ActiveSupport::Testing::TimeHelpers` API Documentation](http://api.rubyonrails.org/classes/ActiveSupport/Testing/TimeHelpers.html) +for in-depth information about the available time helpers. diff --git a/guides/source/threading_and_code_execution.md b/guides/source/threading_and_code_execution.md new file mode 100644 index 0000000000..3d3d31b97e --- /dev/null +++ b/guides/source/threading_and_code_execution.md @@ -0,0 +1,324 @@ +**DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON http://guides.rubyonrails.org.** + +Threading and Code Execution in Rails +===================================== + +After reading this guide, you will know: + +* What code Rails will automatically execute concurrently +* How to integrate manual concurrency with Rails internals +* How to wrap all application code +* How to affect application reloading + +-------------------------------------------------------------------------------- + +Automatic Concurrency +--------------------- + +Rails automatically allows various operations to be performed at the same time. + +When using a threaded web server, such as the default Puma, multiple HTTP +requests will be served simultaneously, with each request provided its own +controller instance. + +Threaded Active Job adapters, including the built-in Async, will likewise +execute several jobs at the same time. Action Cable channels are managed this +way too. + +These mechanisms all involve multiple threads, each managing work for a unique +instance of some object (controller, job, channel), while sharing the global +process space (such as classes and their configurations, and global variables). +As long as your code doesn't modify any of those shared things, it can mostly +ignore that other threads exist. + +The rest of this guide describes the mechanisms Rails uses to make it "mostly +ignorable", and how extensions and applications with special needs can use them. + +Executor +-------- + +The Rails Executor separates application code from framework code: any time the +framework invokes code you've written in your application, it will be wrapped by +the Executor. + +The Executor consists of two callbacks: `to_run` and `to_complete`. The Run +callback is called before the application code, and the Complete callback is +called after. + +### Default callbacks + +In a default Rails application, the Executor callbacks are used to: + +* track which threads are in safe positions for autoloading and reloading +* enable and disable the Active Record query cache +* return acquired Active Record connections to the pool +* constrain internal cache lifetimes + +Prior to Rails 5.0, some of these were handled by separate Rack middleware +classes (such as `ActiveRecord::ConnectionAdapters::ConnectionManagement`), or +directly wrapping code with methods like +`ActiveRecord::Base.connection_pool.with_connection`. The Executor replaces +these with a single more abstract interface. + +### Wrapping application code + +If you're writing a library or component that will invoke application code, you +should wrap it with a call to the executor: + +```ruby +Rails.application.executor.wrap do + # call application code here +end +``` + +TIP: If you repeatedly invoke application code from a long-running process, you +may want to wrap using the Reloader instead. + +Each thread should be wrapped before it runs application code, so if your +application manually delegates work to other threads, such as via `Thread.new` +or Concurrent Ruby features that use thread pools, you should immediately wrap +the block: + +```ruby +Thread.new do + Rails.application.executor.wrap do + # your code here + end +end +``` + +NOTE: Concurrent Ruby uses a `ThreadPoolExecutor`, which it sometimes configures +with an `executor` option. Despite the name, it is unrelated. + +The Executor is safely re-entrant; if it is already active on the current +thread, `wrap` is a no-op. + +If it's impractical to wrap the application code in a block (for +example, the Rack API makes this problematic), you can also use the `run!` / +`complete!` pair: + +```ruby +Thread.new do + execution_context = Rails.application.executor.run! + # your code here +ensure + execution_context.complete! if execution_context +end +``` + +### Concurrency + +The Executor will put the current thread into `running` mode in the Load +Interlock. This operation will block temporarily if another thread is currently +either autoloading a constant or unloading/reloading the application. + +Reloader +-------- + +Like the Executor, the Reloader also wraps application code. If the Executor is +not already active on the current thread, the Reloader will invoke it for you, +so you only need to call one. This also guarantees that everything the Reloader +does, including all its callback invocations, occurs wrapped inside the +Executor. + +```ruby +Rails.application.reloader.wrap do + # call application code here +end +``` + +The Reloader is only suitable where a long-running framework-level process +repeatedly calls into application code, such as for a web server or job queue. +Rails automatically wraps web requests and Active Job workers, so you'll rarely +need to invoke the Reloader for yourself. Always consider whether the Executor +is a better fit for your use case. + +### Callbacks + +Before entering the wrapped block, the Reloader will check whether the running +application needs to be reloaded -- for example, because a model's source file has +been modified. If it determines a reload is required, it will wait until it's +safe, and then do so, before continuing. When the application is configured to +always reload regardless of whether any changes are detected, the reload is +instead performed at the end of the block. + +The Reloader also provides `to_run` and `to_complete` callbacks; they are +invoked at the same points as those of the Executor, but only when the current +execution has initiated an application reload. When no reload is deemed +necessary, the Reloader will invoke the wrapped block with no other callbacks. + +### Class Unload + +The most significant part of the reloading process is the Class Unload, where +all autoloaded classes are removed, ready to be loaded again. This will occur +immediately before either the Run or Complete callback, depending on the +`reload_classes_only_on_change` setting. + +Often, additional reloading actions need to be performed either just before or +just after the Class Unload, so the Reloader also provides `before_class_unload` +and `after_class_unload` callbacks. + +### Concurrency + +Only long-running "top level" processes should invoke the Reloader, because if +it determines a reload is needed, it will block until all other threads have +completed any Executor invocations. + +If this were to occur in a "child" thread, with a waiting parent inside the +Executor, it would cause an unavoidable deadlock: the reload must occur before +the child thread is executed, but it cannot be safely performed while the parent +thread is mid-execution. Child threads should use the Executor instead. + +Framework Behavior +------------------ + +The Rails framework components use these tools to manage their own concurrency +needs too. + +`ActionDispatch::Executor` and `ActionDispatch::Reloader` are Rack middlewares +that wraps the request with a supplied Executor or Reloader, respectively. They +are automatically included in the default application stack. The Reloader will +ensure any arriving HTTP request is served with a freshly-loaded copy of the +application if any code changes have occurred. + +Active Job also wraps its job executions with the Reloader, loading the latest +code to execute each job as it comes off the queue. + +Action Cable uses the Executor instead: because a Cable connection is linked to +a specific instance of a class, it's not possible to reload for every arriving +websocket message. Only the message handler is wrapped, though; a long-running +Cable connection does not prevent a reload that's triggered by a new incoming +request or job. Instead, Action Cable uses the Reloader's `before_class_unload` +callback to disconnect all its connections. When the client automatically +reconnects, it will be speaking to the new version of the code. + +The above are the entry points to the framework, so they are responsible for +ensuring their respective threads are protected, and deciding whether a reload +is necessary. Other components only need to use the Executor when they spawn +additional threads. + +### Configuration + +The Reloader only checks for file changes when `cache_classes` is false and +`reload_classes_only_on_change` is true (which is the default in the +`development` environment). + +When `cache_classes` is true (in `production`, by default), the Reloader is only +a pass-through to the Executor. + +The Executor always has important work to do, like database connection +management. When `cache_classes` and `eager_load` are both true (`production`), +no autoloading or class reloading will occur, so it does not need the Load +Interlock. If either of those are false (`development`), then the Executor will +use the Load Interlock to ensure constants are only loaded when it is safe. + +Load Interlock +-------------- + +The Load Interlock allows autoloading and reloading to be enabled in a +multi-threaded runtime environment. + +When one thread is performing an autoload by evaluating the class definition +from the appropriate file, it is important no other thread encounters a +reference to the partially-defined constant. + +Similarly, it is only safe to perform an unload/reload when no application code +is in mid-execution: after the reload, the `User` constant, for example, may +point to a different class. Without this rule, a poorly-timed reload would mean +`User.new.class == User`, or even `User == User`, could be false. + +Both of these constraints are addressed by the Load Interlock. It keeps track of +which threads are currently running application code, loading a class, or +unloading autoloaded constants. + +Only one thread may load or unload at a time, and to do either, it must wait +until no other threads are running application code. If a thread is waiting to +perform a load, it doesn't prevent other threads from loading (in fact, they'll +cooperate, and each perform their queued load in turn, before all resuming +running together). + +### `permit_concurrent_loads` + +The Executor automatically acquires a `running` lock for the duration of its +block, and autoload knows when to upgrade to a `load` lock, and switch back to +`running` again afterwards. + +Other blocking operations performed inside the Executor block (which includes +all application code), however, can needlessly retain the `running` lock. If +another thread encounters a constant it must autoload, this can cause a +deadlock. + +For example, assuming `User` is not yet loaded, the following will deadlock: + +```ruby +Rails.application.executor.wrap do + th = Thread.new do + Rails.application.executor.wrap do + User # inner thread waits here; it cannot load + # User while another thread is running + end + end + + th.join # outer thread waits here, holding 'running' lock +end +``` + +To prevent this deadlock, the outer thread can `permit_concurrent_loads`. By +calling this method, the thread guarantees it will not dereference any +possibly-autoloaded constant inside the supplied block. The safest way to meet +that promise is to put it as close as possible to the blocking call: + +```ruby +Rails.application.executor.wrap do + th = Thread.new do + Rails.application.executor.wrap do + User # inner thread can acquire the load lock, + # load User, and continue + end + end + + ActiveSupport::Dependencies.interlock.permit_concurrent_loads do + th.join # outer thread waits here, but has no lock + end +end +``` + +Another example, using Concurrent Ruby: + +```ruby +Rails.application.executor.wrap do + futures = 3.times.collect do |i| + Concurrent::Future.execute do + Rails.application.executor.wrap do + # do work here + end + end + end + + values = ActiveSupport::Dependencies.interlock.permit_concurrent_loads do + futures.collect(&:value) + end +end +``` + + +### ActionDispatch::DebugLocks + +If your application is deadlocking and you think the Load Interlock may be +involved, you can temporarily add the ActionDispatch::DebugLocks middleware to +`config/application.rb`: + +```ruby +config.middleware.insert_before Rack::Sendfile, + ActionDispatch::DebugLocks +``` + +If you then restart the application and re-trigger the deadlock condition, +`/rails/locks` will show a summary of all threads currently known to the +interlock, which lock level they are holding or awaiting, and their current +backtrace. + +Generally a deadlock will be caused by the interlock conflicting with some other +external lock or blocking I/O call. Once you find it, you can wrap it with +`permit_concurrent_loads`. + diff --git a/guides/source/upgrading_ruby_on_rails.md b/guides/source/upgrading_ruby_on_rails.md index 05c46a9e76..33ab50b0e8 100644 --- a/guides/source/upgrading_ruby_on_rails.md +++ b/guides/source/upgrading_ruby_on_rails.md @@ -1,7 +1,7 @@ **DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON http://guides.rubyonrails.org.** -A Guide for Upgrading Ruby on Rails -=================================== +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. @@ -16,26 +16,41 @@ Before attempting to upgrade an existing application, you should be sure you hav The best way to be sure that your application still works after upgrading is to have good test coverage before you start the process. If you don't have automated tests that exercise the bulk of your application, you'll need to spend time manually exercising all the parts that have changed. In the case of a Rails upgrade, that will mean every single piece of functionality in the application. Do yourself a favor and make sure your test coverage is good _before_ you start an upgrade. +### The Upgrade Process + +When changing Rails versions, it's best to move slowly, one minor version at a time, in order to make good use of the deprecation warnings. Rails version numbers are in the form Major.Minor.Patch. Major and Minor versions are allowed to make changes to the public API, so this may cause errors in your application. Patch versions only include bug fixes, and don't change any public API. + +The process should go as follows: + +1. Write tests and make sure they pass. +2. Move to the latest patch version after your current version. +3. Fix tests and deprecated features. +4. Move to the latest patch version of the next minor version. + +Repeat this process until you reach your target Rails version. Each time you move versions, you will need to change the Rails version number in the `Gemfile` (and possibly other gem versions) and run `bundle update`. Then run the Update task mentioned below to update configuration files, then run your tests. + +You can find a list of all released Rails versions [here](https://rubygems.org/gems/rails/versions). + ### Ruby Versions Rails generally stays close to the latest released Ruby version when it's released: -* Rails 5 requires Ruby 2.2.1 or newer. +* Rails 5 requires Ruby 2.2.2 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 straight to 1.9.3 for smooth sailing. -### The Rake Task +### The Update Task -Rails provides the `rails:update` rake task. After updating the Rails version -in the Gemfile, run this rake task. +Rails provides the `app:update` task (`rake rails:update` on 4.2 and earlier). After updating the Rails version +in the `Gemfile`, run this task. This will help you with the creation of new files and changes of old files in an interactive session. ```bash -$ rake rails:update +$ rails app:update identical config/boot.rb exist config conflict config/routes.rb @@ -50,41 +65,357 @@ Overwrite /myapp/config/application.rb? (enter "h" for help) [Ynaqdh] Don't forget to review the difference, to see if there were any unexpected changes. +Upgrading from Rails 5.0 to Rails 5.1 +------------------------------------- + +For more information on changes made to Rails 5.1 please see the [release notes](5_1_release_notes.html). + +### Top-level `HashWithIndifferentAccess` is soft-deprecated + +If your application uses the top-level `HashWithIndifferentAccess` class, you +should slowly move your code to instead use `ActiveSupport::HashWithIndifferentAccess`. + +It is only soft-deprecated, which means that your code will not break at the +moment and no deprecation warning will be displayed, but this constant will be +removed in the future. + +Also, if you have pretty old YAML documents containing dumps of such objects, +you may need to load and dump them again to make sure that they reference +the right constant, and that loading them won't break in the future. + +### `application.secrets` now loaded with all keys as symbols + +If your application stores nested configuration in `config/secrets.yml`, all keys +are now loaded as symbols, so access using strings should be changed. + +From: + +```ruby +Rails.application.secrets[:smtp_settings]["address"] +``` + +To: + +```ruby +Rails.application.secrets[:smtp_settings][:address] +``` + Upgrading from Rails 4.2 to Rails 5.0 ------------------------------------- -### Halting callback chains by returning `false` +For more information on changes made to Rails 5.0 please see the [release notes](5_0_release_notes.html). + +### Ruby 2.2.2+ required -In Rails 4.2, when a 'before' callback returns `false` in ActiveRecord, -ActiveModel and ActiveModel::Validations, then the entire callback chain -is halted. In other words, successive 'before' callbacks are not executed, -and neither is the action wrapped in callbacks. +From Ruby on Rails 5.0 onwards, Ruby 2.2.2+ is the only supported Ruby version. +Make sure you are on Ruby 2.2.2 version or greater, before you proceed. -In Rails 5.0, returning `false` in a callback will not have this side effect -of halting the callback chain. Instead, callback chains must be explicitly -halted by calling `throw(:abort)`. +### Active Record Models Now Inherit from ApplicationRecord by Default -When you upgrade from Rails 4.2 to Rails 5.0, returning `false` in a callback -will still halt the callback chain, but you will receive a deprecation warning -about this upcoming change. +In Rails 4.2, an Active Record model inherits from `ActiveRecord::Base`. In Rails 5.0, +all models inherit from `ApplicationRecord`. + +`ApplicationRecord` is a new superclass for all app models, analogous to app +controllers subclassing `ApplicationController` instead of +`ActionController::Base`. This gives apps a single spot to configure app-wide +model behavior. + +When upgrading from Rails 4.2 to Rails 5.0, you need to create an +`application_record.rb` file in `app/models/` and add the following content: + +``` +class ApplicationRecord < ActiveRecord::Base + self.abstract_class = true +end +``` + +Then make sure that all your models inherit from it. + +### Halting Callback Chains via `throw(:abort)` + +In Rails 4.2, when a 'before' callback returns `false` in Active Record +and Active Model, then the entire callback chain is halted. In other words, +successive 'before' callbacks are not executed, and neither is the action wrapped +in callbacks. + +In Rails 5.0, returning `false` in an Active Record or Active Model callback +will not have this side effect of halting the callback chain. Instead, callback +chains must be explicitly halted by calling `throw(:abort)`. + +When you upgrade from Rails 4.2 to Rails 5.0, returning `false` in those kind of +callbacks will still halt the callback chain, but 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 the following configuration to your `config/application.rb`: - config.active_support.halt_callback_chains_on_return_false = false + ActiveSupport.halt_callback_chains_on_return_false = false + +Note that this option will not affect Active Support callbacks since they never +halted the chain when any value was returned. See [#17227](https://github.com/rails/rails/pull/17227) for more details. +### ActiveJob Now Inherits from ApplicationJob by Default + +In Rails 4.2, an Active Job inherits from `ActiveJob::Base`. In Rails 5.0, this +behavior has changed to now inherit from `ApplicationJob`. + +When upgrading from Rails 4.2 to Rails 5.0, you need to create an +`application_job.rb` file in `app/jobs/` and add the following content: + +``` +class ApplicationJob < ActiveJob::Base +end +``` + +Then make sure that all your job classes inherit from it. + +See [#19034](https://github.com/rails/rails/pull/19034) for more details. + +### Rails Controller Testing + +#### Extraction of some helper methods to `rails-controller-testing` + +`assigns` and `assert_template` have been extracted to the `rails-controller-testing` gem. To +continue using these methods in your controller tests, add `gem 'rails-controller-testing'` to +your `Gemfile`. + +If you are using Rspec for testing, please see the extra configuration required in the gem's +documentation. + +#### New behavior when uploading files + +If you are using `ActionDispatch::Http::UploadedFile` in your tests to +upload files, you will need to change to use the similar `Rack::Test::UploadedFile` +class instead. + +See [#26404](https://github.com/rails/rails/issues/26404) for more details. + +### Autoloading is Disabled After Booting in the Production Environment + +Autoloading is now disabled after booting in the production environment by +default. + +Eager loading the application is part of the boot process, so top-level +constants are fine and are still autoloaded, no need to require their files. + +Constants in deeper places only executed at runtime, like regular method bodies, +are also fine because the file defining them will have been eager loaded while booting. + +For the vast majority of applications this change needs no action. But in the +very rare event that your application needs autoloading while running in +production mode, set `Rails.application.config.enable_dependency_loading` to +true. + +### XML Serialization + +`ActiveModel::Serializers::Xml` has been extracted from Rails to the `activemodel-serializers-xml` +gem. To continue using XML serialization in your application, add `gem 'activemodel-serializers-xml'` +to your `Gemfile`. + +### Removed Support for Legacy `mysql` Database Adapter + +Rails 5 removes support for the legacy `mysql` database adapter. Most users should be able to +use `mysql2` instead. It will be converted to a separate gem when we find someone to maintain +it. + +### Removed Support for Debugger + +`debugger` is not supported by Ruby 2.2 which is required by Rails 5. Use `byebug` instead. + +### Use bin/rails for running tasks and tests + +Rails 5 adds the ability to run tasks and tests through `bin/rails` instead of rake. Generally +these changes are in parallel with rake, but some were ported over altogether. + +To use the new test runner simply type `bin/rails test`. + +`rake dev:cache` is now `rails dev:cache`. + +Run `bin/rails` to see the list of commands available. + +### `ActionController::Parameters` No Longer Inherits from `HashWithIndifferentAccess` + +Calling `params` in your application will now return an object instead of a hash. If your +parameters are already permitted, then you will not need to make any changes. If you are using `map` +and other methods that depend on being able to read the hash regardless of `permitted?` you will +need to upgrade your application to first permit and then convert to a hash. + + params.permit([:proceed_to, :return_to]).to_h + +### `protect_from_forgery` Now Defaults to `prepend: false` + +`protect_from_forgery` defaults to `prepend: false` which means that it will be inserted into +the callback chain at the point in which you call it in your application. If you want +`protect_from_forgery` to always run first, then you should change your application to use +`protect_from_forgery prepend: true`. + +### Default Template Handler is Now RAW + +Files without a template handler in their extension will be rendered using the raw handler. +Previously Rails would render files using the ERB template handler. + +If you do not want your file to be handled via the raw handler, you should add an extension +to your file that can be parsed by the appropriate template handler. + +### Added Wildcard Matching for Template Dependencies + +You can now use wildcard matching for your template dependencies. For example, if you were +defining your templates as such: + +```erb +<% # Template Dependency: recordings/threads/events/subscribers_changed %> +<% # Template Dependency: recordings/threads/events/completed %> +<% # Template Dependency: recordings/threads/events/uncompleted %> +``` + +You can now just call the dependency once with a wildcard. + +```erb +<% # Template Dependency: recordings/threads/events/* %> +``` + +### `ActionView::Helpers::RecordTagHelper` moved to external gem (record_tag_helper) + +`content_tag_for` and `div_for` have been removed in favor of just using `content_tag`. To continue using the older methods, add the `record_tag_helper` gem to your `Gemfile`: + +```ruby +gem 'record_tag_helper', '~> 1.0' +``` + +See [#18411](https://github.com/rails/rails/pull/18411) for more details. + +### Removed Support for `protected_attributes` Gem + +The `protected_attributes` gem is no longer supported in Rails 5. + +### Removed support for `activerecord-deprecated_finders` gem + +The `activerecord-deprecated_finders` gem is no longer supported in Rails 5. + +### `ActiveSupport::TestCase` Default Test Order is Now Random + +When tests are run in your application, the default order is now `:random` +instead of `:sorted`. Use the following config option to set it back to `:sorted`. + +```ruby +# config/environments/test.rb +Rails.application.configure do + config.active_support.test_order = :sorted +end +``` + +### `ActionController::Live` became a `Concern` + +If you include `ActionController::Live` in another module that is included in your controller, then you +should also extend the module with `ActiveSupport::Concern`. Alternatively, you can use the `self.included` hook +to include `ActionController::Live` directly to the controller once the `StreamingSupport` is included. + +This means that if your application used to have its own streaming module, the following code +would break in production mode: + +```ruby +# This is a work-around for streamed controllers performing authentication with Warden/Devise. +# See https://github.com/plataformatec/devise/issues/2332 +# Authenticating in the router is another solution as suggested in that issue +class StreamingSupport + include ActionController::Live # this won't work in production for Rails 5 + # extend ActiveSupport::Concern # unless you uncomment this line. + + def process(name) + super(name) + rescue ArgumentError => e + if e.message == 'uncaught throw :warden' + throw :warden + else + raise e + end + end +end +``` + +### New Framework Defaults + +#### Active Record `belongs_to` Required by Default Option + +`belongs_to` will now trigger a validation error by default if the association is not present. + +This can be turned off per-association with `optional: true`. + +This default will be automatically configured in new applications. If existing application +want to add this feature it will need to be turned on in an initializer. + + config.active_record.belongs_to_required_by_default = true + +#### Per-form CSRF Tokens + +Rails 5 now supports per-form CSRF tokens to mitigate against code-injection attacks with forms +created by JavaScript. With this option turned on, forms in your application will each have their +own CSRF token that is specified to the action and method for that form. + + config.action_controller.per_form_csrf_tokens = true + +#### Forgery Protection with Origin Check + +You can now configure your application to check if the HTTP `Origin` header should be checked +against the site's origin as an additional CSRF defense. Set the following in your config to +true: + + config.action_controller.forgery_protection_origin_check = true + +#### Allow Configuration of Action Mailer Queue Name + +The default mailer queue name is `mailers`. This configuration option allows you to globally change +the queue name. Set the following in your config: + + config.action_mailer.deliver_later_queue_name = :new_queue_name + +#### Support Fragment Caching in Action Mailer Views + +Set `config.action_mailer.perform_caching` in your config to determine whether your Action Mailer views +should support caching. + + config.action_mailer.perform_caching = true + +#### Configure the Output of `db:structure:dump` + +If you're using `schema_search_path` or other PostgreSQL extensions, you can control how the schema is +dumped. Set to `:all` to generate all dumps, or to `:schema_search_path` to generate from schema search path. + + config.active_record.dump_schemas = :all + +#### Configure SSL Options to Enable HSTS with Subdomains + +Set the following in your config to enable HSTS when using subdomains: + + config.ssl_options = { hsts: { subdomains: true } } + +#### Preserve Timezone of the Receiver + +When using Ruby 2.4, you can preserve the timezone of the receiver when calling `to_time`. + + ActiveSupport.to_time_preserves_timezone = false + +### Changes with JSON/JSONB serialization + +In Rails 5.0, how JSON/JSONB attributes are serialized and deserialized changed. Now, if +you set a column equal to a `String`, Active Record will no longer turn that string +into a `Hash`, and will instead only return the string. This is not limited to code +interacting with models, but also affects `:default` column settings in `db/schema.rb`. +It is recommended that you do not set columns equal to a `String`, but pass a `Hash` +instead, which will be converted to and from a JSON string automatically. + 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. +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: +`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 @@ -125,7 +456,7 @@ 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 +When you define an `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 @@ -228,7 +559,7 @@ Read the [gem's readme](https://github.com/rails/rails-html-sanitizer) for more 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: +If your application needs to use the old sanitizer implementation, include `rails-deprecated_sanitizer` in your `Gemfile`: ```ruby gem 'rails-deprecated_sanitizer' @@ -281,12 +612,12 @@ end The migration DSL has been expanded to support foreign key definitions. If you've been using the Foreigner gem, you might want to consider removing it. Note that the foreign key support of Rails is a subset of Foreigner. This means -that not every Foreigner definition can be fully replaced by it's Rails +that not every Foreigner definition can be fully replaced by its Rails migration DSL counterpart. The migration procedure is as follows: -1. remove `gem "foreigner"` from the Gemfile. +1. remove `gem "foreigner"` from the `Gemfile`. 2. run `bundle install`. 3. run `bin/rake db:schema:dump`. 4. make sure that `db/schema.rb` contains every foreign key definition with @@ -297,11 +628,11 @@ Upgrading from Rails 4.0 to Rails 4.1 ### CSRF protection from remote `<script>` tags -Or, "whaaat my tests are failing!!!?" +Or, "whaaat my tests are failing!!!?" or "my `<script>` widget is busted!!" 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. +JavaScript responses, too. This prevents a third-party site from remotely +referencing your JavaScript with a `<script>` tag to extract sensitive data. This means that your functional and integration tests that use @@ -317,8 +648,9 @@ 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. +Note: Your own `<script>` tags are treated as cross-origin and blocked by +default, too. If you really mean to load JavaScript from `<script>` tags, +you must now explicitly skip CSRF protection on those actions. ### Spring @@ -435,15 +767,15 @@ There are a few major changes related to JSON handling in Rails 4.1. 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: +If your application currently depends 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 +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). +deserializing arbitrary Ruby objects and are generally [unsafe](http://www.ruby-doc.org/stdlib-2.2.2/libdoc/json/rdoc/JSON.html#method-i-load). #### JSON gem compatibility @@ -478,7 +810,7 @@ part of the rewrite, the following features have been removed from the encoder: 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. +gem to your `Gemfile`. #### JSON representation of Time objects @@ -774,7 +1106,7 @@ on the Rails blog. 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 +such format is [JSON Patch](https://tools.ietf.org/html/rfc6902). While Rails does not support JSON Patch natively, it's easy enough to add support: ``` @@ -803,8 +1135,8 @@ 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 +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 @@ -815,13 +1147,13 @@ 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`. +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`. ### Active Record * Rails 4.0 has removed the identity map from Active Record, due to [some inconsistencies with associations](https://github.com/rails/rails/commit/302c912bf6bcd0fa200d964ec2dc4a44abe328a6). If you have manually enabled it in your application, you will have to remove the following config that has no effect anymore: `config.active_record.identity_map`. -* 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. +* The `delete` method in collection associations can now receive `Integer` 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. * 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. @@ -866,9 +1198,23 @@ this gem such as `whitelist_attributes` or `mass_assignment_sanitizer` options. * To re-enable the old finders, you can use the [activerecord-deprecated_finders gem](https://github.com/rails/activerecord-deprecated_finders). +* Rails 4.0 has changed to default join table for `has_and_belongs_to_many` relations to strip the common prefix off the second table name. Any existing `has_and_belongs_to_many` relationship between models with a common prefix must be specified with the `join_table` option. For example: + +```ruby +CatalogCategory < ActiveRecord::Base + has_and_belongs_to_many :catalog_products, join_table: 'catalog_categories_catalog_products' +end + +CatalogProduct < ActiveRecord::Base + has_and_belongs_to_many :catalog_categories, join_table: 'catalog_categories_catalog_products' +end +``` + +* Note that the prefix takes scopes into account as well, so relations between `Catalog::Category` and `Catalog::Product` or `Catalog::Category` and `CatalogProduct` need to be updated similarly. + ### 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. +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 @@ -895,7 +1241,7 @@ Rails 4.0 extracted Active Resource to its own gem. If you still need the featur 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. +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. @@ -905,10 +1251,12 @@ Please read [Pull Request #9978](https://github.com/rails/rails/pull/9978) for d * Rails 4.0 has deprecated `ActionController::Base.page_cache_extension` option. Use `ActionController::Base.default_static_extension` instead. -* 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 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_page` 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 `layout` lookup set using symbols or procs that return nil. To get the "no layout" behavior, return false instead of nil. + * 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. @@ -962,7 +1310,7 @@ get 'こんにちは', controller: 'welcome', action: 'index' 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`. +* Rails 4.0 has removed `ActionDispatch::BestStandardsSupport` middleware, `<!DOCTYPE html>` already triggers standards mode per https://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: @@ -994,6 +1342,10 @@ Also check your environment settings for `config.action_dispatch.best_standards_ Rails 4.0 removes the `j` alias for `ERB::Util#json_escape` since `j` is already used for `ActionView::Helpers::JavaScriptHelper#escape_javascript`. +#### Cache + +The caching method changed between Rails 3.x and 4.0. You should [change the cache namespace](http://guides.rubyonrails.org/caching_with_rails.html#activesupport-cache-store) and roll out with a cold cache. + ### Helpers Loading Order 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. @@ -1053,7 +1405,7 @@ config.active_record.auto_explain_threshold_in_seconds = 0.5 ### config/environments/test.rb -The `mass_assignment_sanitizer` configuration setting should also be be added to `config/environments/test.rb`: +The `mass_assignment_sanitizer` configuration setting should also be added to `config/environments/test.rb`: ```ruby # Raise exception on mass assignment protection for Active Record models @@ -1062,7 +1414,7 @@ config.active_record.mass_assignment_sanitizer = :strict ### vendor/plugins -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`. +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 @@ -1142,7 +1494,7 @@ config.assets.digest = true # config.assets.manifest = YOUR_PATH # Precompile additional assets (application.js, application.css, and all non-JS/CSS are already added) -# config.assets.precompile += %w( search.js ) +# config.assets.precompile += %w( admin.js admin.css ) # Force all access to the app over SSL, use Strict-Transport-Security, and use secure cookies. # config.force_ssl = true @@ -1154,8 +1506,10 @@ 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_files = true -config.static_cache_control = 'public, max-age=3600' +config.public_file_server.enabled = true +config.public_file_server.headers = { + 'Cache-Control' => 'public, max-age=3600' +} ``` ### config/initializers/wrap_parameters.rb diff --git a/guides/source/working_with_javascript_in_rails.md b/guides/source/working_with_javascript_in_rails.md index e3856a285a..c3dff1772c 100644 --- a/guides/source/working_with_javascript_in_rails.md +++ b/guides/source/working_with_javascript_in_rails.md @@ -24,11 +24,11 @@ In order to understand Ajax, you must first understand what a web browser does normally. When you type `http://localhost:3000` into your browser's address bar and hit -'Go,' the browser (your 'client') makes a request to the server. It parses the +'Go', the browser (your 'client') makes a request to the server. It parses the response, then fetches all associated assets, like JavaScript files, stylesheets and images. It then assembles the page. If you click a link, it does the same process: fetch the page, fetch the assets, put it all together, -show you the results. This is called the 'request response cycle.' +show you the results. This is called the 'request response cycle'. JavaScript can also make requests to the server, and parse the response. It also has the ability to update information on the page. Combining these two @@ -57,7 +57,7 @@ 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 -------------------------------------- +---------------------- Rails uses a technique called "Unobtrusive JavaScript" to handle attaching JavaScript to the DOM. This is generally considered to be a best-practice @@ -81,7 +81,7 @@ Awkward, right? We could pull the function definition out of the click handler, and turn it into CoffeeScript: ```coffeescript -paintIt = (element, backgroundColor, textColor) -> +@paintIt = (element, backgroundColor, textColor) -> element.style.backgroundColor = backgroundColor if textColor? element.style.color = textColor @@ -107,7 +107,7 @@ attribute to our link, and then bind a handler to the click event of every link that has that attribute: ```coffeescript -paintIt = (element, backgroundColor, textColor) -> +@paintIt = (element, backgroundColor, textColor) -> element.style.backgroundColor = backgroundColor if textColor? element.style.color = textColor @@ -139,7 +139,9 @@ JavaScript) in this style, and you can expect that many libraries will also follow this pattern. Built-in Helpers ----------------------- +---------------- + +### Remote elements Rails provides a bunch of view helper methods written in Ruby to assist you in generating HTML. Sometimes, you want to add a little Ajax to those elements, @@ -148,19 +150,23 @@ and Rails has got your back in those cases. Because of Unobtrusive JavaScript, the Rails "Ajax helpers" are actually in two parts: the JavaScript half and the Ruby half. -[rails.js](https://github.com/rails/jquery-ujs/blob/master/src/rails.js) +Unless you have disabled the Asset Pipeline, +[rails-ujs](https://github.com/rails/rails/tree/master/actionview/app/assets/javascripts) provides the JavaScript half, and the regular Ruby view helpers add appropriate -tags to your DOM. The CoffeeScript in rails.js then listens for these -attributes, and attaches appropriate handlers. +tags to your DOM. -### form_for +You can read below about the different events that are fired dealing with +remote elements inside your application. -[`form_for`](http://api.rubyonrails.org/classes/ActionView/Helpers/FormHelper.html#method-i-form_for) -is a helper that assists with writing forms. `form_for` takes a `:remote` -option. It works like this: +#### form_with + +[`form_with`](http://api.rubyonrails.org/classes/ActionView/Helpers/FormHelper.html#method-i-form_with) +is a helper that assists with writing forms. By default, `form_with` assumes that +your form will be using Ajax. You can opt out of this behavior by +passing the `:local` option `form_with`. ```erb -<%= form_for(@article, remote: true) do |f| %> +<%= form_with(model: @article) do |f| %> ... <% end %> ``` @@ -168,7 +174,7 @@ option. It works like this: This will generate the following HTML: ```html -<form accept-charset="UTF-8" action="/articles" class="new_article" data-remote="true" id="new_article" method="post"> +<form action="/articles" accept-charset="UTF-8" method="post" data-remote="true"> ... </form> ``` @@ -182,67 +188,21 @@ bind to the `ajax:success` event. On failure, use `ajax:error`. Check it out: ```coffeescript $(document).ready -> - $("#new_article").on("ajax:success", (e, data, status, xhr) -> + $("#new_article").on("ajax:success", (event) -> + [data, status, xhr] = event.detail $("#new_article").append xhr.responseText - ).on "ajax:error", (e, xhr, status, error) -> + ).on "ajax:error", (event) -> $("#new_article").append "<p>ERROR</p>" ``` Obviously, you'll want to be a bit more sophisticated than that, but it's a -start. You can see more about the events [in the jquery-ujs wiki](https://github.com/rails/jquery-ujs/wiki/ajax). - -Another possibility is returning javascript directly from the server side on -remote calls: - -```ruby -# articles_controller -def create - respond_to do |format| - if @article.save - format.html { ... } - format.js do - render js: <<-endjs - alert('Article saved successfully!'); - window.location = '#{article_path(@article)}'; - endjs - end - else - format.html { ... } - format.js do - render js: "alert('There are empty fields in the form!');" - end - end - end -end -``` - -NOTE: If javascript is disabled in the user browser, `format.html { ... }` -block should be executed as fallback. +start. -### form_tag - -[`form_tag`](http://api.rubyonrails.org/classes/ActionView/Helpers/FormTagHelper.html#method-i-form_tag) -is very similar to `form_for`. It has a `:remote` option that you can use like -this: +NOTE: As of Rails 5.1 and the new `rails-ujs`, the parameters `data, status, xhr` +have been bundled into `event.detail`. For information about the previously used +`jquery-ujs` in Rails 5 and earlier, read the [`jquery-ujs` wiki](https://github.com/rails/jquery-ujs/wiki/ajax). -```erb -<%= 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 -details. - -### link_to +#### link_to [`link_to`](http://api.rubyonrails.org/classes/ActionView/Helpers/UrlHelper.html#method-i-link_to) is a helper that assists with generating links. It has a `:remote` option you @@ -258,7 +218,7 @@ which generates <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 +You can bind to the same Ajax events as `form_with`. Here's an example. Let's assume that we have a list of articles that can be deleted with just one click. We would generate some HTML like this: @@ -270,11 +230,11 @@ and write some CoffeeScript like this: ```coffeescript $ -> - $("a[data-remote]").on "ajax:success", (e, data, status, xhr) -> + $("a[data-remote]").on "ajax:success", (event) -> alert "The article was deleted." ``` -### button_to +#### button_to [`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: @@ -286,11 +246,152 @@ this generates ```html <form action="/articles/1" class="button_to" data-remote="true" method="post"> - <div><input type="submit" value="An article"></div> + <input type="submit" value="An article" /> </form> ``` -Since it's just a `<form>`, all of the information on `form_for` also applies. +Since it's just a `<form>`, all of the information on `form_with` also applies. + +### Customize remote elements + +It is possible to customize the behavior of elements with a `data-remote` +attribute without writing a line of JavaScript. You can specify extra `data-` +attributes to accomplish this. + +#### `data-method` + +Activating hyperlinks always results in an HTTP GET request. However, if your +application is [RESTful](https://en.wikipedia.org/wiki/Representational_State_Transfer), +some links are in fact actions that change data on the server, and must be +performed with non-GET requests. This attribute allows marking up such links +with an explicit method such as "post", "put" or "delete". + +The way it works is that, when the link is activated, it constructs a hidden form +in the document with the "action" attribute corresponding to "href" value of the +link, and the method corresponding to `data-method` value, and submits that form. + +NOTE: Because submitting forms with HTTP methods other than GET and POST isn't +widely supported across browsers, all other HTTP methods are actually sent over +POST with the intended method indicated in the `_method` parameter. Rails +automatically detects and compensates for this. + +#### `data-url` and `data-params` + +Certain elements of your page aren't actually referring to any URL, but you may want +them to trigger Ajax calls. Specifying the `data-url` attribute along with +the `data-remote` one will trigger an Ajax call to the given URL. You can also +specify extra parameters through the `data-params` attribute. + +This can be useful to trigger an action on check-boxes for instance: + +```html +<input type="checkbox" data-remote="true" + data-url="/update" data-params="id=10" data-method="put"> +``` + +#### `data-type` + +It is also possible to define the Ajax `dataType` explicitly while performing +requests for `data-remote` elements, by way of the `data-type` attribute. + +### Confirmations + +You can ask for an extra confirmation of the user by adding a `data-confirm` +attribute on links and forms. The user will be presented a JavaScript `confirm()` +dialog containing the attribute's text. If the user chooses to cancel, the action +doesn't take place. + +Adding this attribute on links will trigger the dialog on click, and adding it +on forms will trigger it on submit. For example: + +```erb +<%= link_to "Dangerous zone", dangerous_zone_path, + data: { confirm: 'Are you sure?' } %> +``` + +This generates: + +```html +<a href="..." data-confirm="Are you sure?">Dangerous zone</a> +``` + +The attribute is also allowed on form submit buttons. This allows you to customize +the warning message depending on the button which was activated. In this case, +you should **not** have `data-confirm` on the form itself. + +The default confirmation uses a JavaScript confirm dialog, but you can customize +this by listening to the `confirm` event, which is fired just before the confirmation +window appears to the user. To cancel this default confirmation, have the confirm +handler to return `false`. + +### Automatic disabling + +It is also possible to automatically disable an input while the form is submitting +by using the `data-disable-with` attribute. This is to prevent accidental +double-clicks from the user, which could result in duplicate HTTP requests that +the backend may not detect as such. The value of the attribute is the text that will +become the new value of the button in its disabled state. + +This also works for links with `data-method` attribute. + +For example: + +```erb +<%= form_with(model: @article.new) do |f| %> + <%= f.submit data: { "disable-with": "Saving..." } %> +<%= end %> +``` + +This generates a form with: + +```html +<input data-disable-with="Saving..." type="submit"> +``` + +### Rails-ujs event handlers + +Rails 5.1 introduced rails-ujs and dropped jQuery as a dependency. +As a result the Unobtrusive JavaScript (UJS) driver has been rewritten to operate without jQuery. +These introductions cause small changes to `custom events` fired during the request: + +NOTE: Signature of calls to UJS's event handlers has changed. +Unlike the version with jQuery, all custom events return only one parameter: `event`. +In this parameter, there is an additional attribute `detail` which contains an array of extra parameters. + +| Event name | Extra parameters (event.detail) | Fired | +|---------------------|---------------------------------|-------------------------------------------------------------| +| `ajax:before` | | Before the whole ajax business. | +| `ajax:beforeSend` | [xhr, options] | Before the request is sent. | +| `ajax:send` | [xhr] | When the request is sent. | +| `ajax:stopped` | | When the request is stopped. | +| `ajax:success` | [response, status, xhr] | After completion, if the response was a success. | +| `ajax:error` | [response, status, xhr] | After completion, if the response was an error. | +| `ajax:complete` | [xhr, status] | After the request has been completed, no matter the outcome.| + +Example usage: + +```html +document.body.addEventListener('ajax:success', function(event) { + var detail = event.detail; + var data = detail[0], status = detail[1], xhr = detail[2]; +}) +``` + +NOTE: As of Rails 5.1 and the new `rails-ujs`, the parameters `data, status, xhr` +have been bundled into `event.detail`. For information about the previously used +`jquery-ujs` in Rails 5 and earlier, read the [`jquery-ujs` wiki](https://github.com/rails/jquery-ujs/wiki/ajax). + +### Stoppable events + +If you stop `ajax:before` or `ajax:beforeSend` by returning false from the +handler method, the Ajax request will never take place. The `ajax:before` event +can manipulate form data before serialization and the +`ajax:beforeSend` event is useful for adding custom request headers. + +If you stop the `ajax:aborted:file` event, the default behavior of allowing the +browser to submit the form via normal means (i.e. non-Ajax submission) will be +canceled and the form will not be submitted at all. This is useful for +implementing your own Ajax file upload workaround. Server-Side Concerns -------------------- @@ -325,7 +426,7 @@ The index view (`app/views/users/index.html.erb`) contains: <br> -<%= form_for(@user, remote: true) do |f| %> +<%= form_with(model: @user) do |f| %> <%= f.label :name %><br> <%= f.text_field :name %> <%= f.submit %> @@ -356,7 +457,7 @@ this: respond_to do |format| if @user.save format.html { redirect_to @user, notice: 'User was successfully created.' } - format.js {} + format.js format.json { render json: @user, status: :created, location: @user } else format.html { render action: "new" } @@ -366,7 +467,7 @@ this: end ``` -Notice the format.js in the `respond_to` block; that allows the controller to +Notice the `format.js` in the `respond_to` block: that allows the controller to respond to your Ajax request. You then have a corresponding `app/views/users/create.js.erb` view file that generates the actual JavaScript code that will be sent and executed on the client side. @@ -378,28 +479,28 @@ $("<%= escape_javascript(render @user) %>").appendTo("#users"); Turbolinks ---------- -Rails 4 ships with the [Turbolinks gem](https://github.com/rails/turbolinks). -This gem uses Ajax to speed up page rendering in most applications. +Rails ships with the [Turbolinks library](https://github.com/turbolinks/turbolinks), +which uses Ajax to speed up page rendering in most applications. ### How Turbolinks Works -Turbolinks attaches a click handler to all `<a>` on the page. If your browser +Turbolinks attaches a click handler to all `<a>` tags on the page. If your browser supports -[PushState](https://developer.mozilla.org/en-US/docs/Web/Guide/API/DOM/Manipulating_the_browser_history#The_pushState()_method), +[PushState](https://developer.mozilla.org/en-US/docs/Web/Guide/API/DOM/Manipulating_the_browser_history#The_pushState%28%29_method), Turbolinks will make an Ajax request for the page, parse the response, and replace the entire `<body>` of the page with the `<body>` of the response. It will then use PushState to change the URL to the correct one, preserving refresh semantics and giving you pretty URLs. -The only thing you have to do to enable Turbolinks is have it in your Gemfile, -and put `//= require turbolinks` in your CoffeeScript manifest, which is usually +The only thing you have to do to enable Turbolinks is have it in your `Gemfile`, +and put `//= require turbolinks` in your JavaScript manifest, which is usually `app/assets/javascripts/application.js`. -If you want to disable Turbolinks for certain links, add a `data-no-turbolink` +If you want to disable Turbolinks for certain links, add a `data-turbolinks="false"` attribute to the tag: ```html -<a href="..." data-no-turbolink>No turbolinks here</a>. +<a href="..." data-turbolinks="false">No turbolinks here</a>. ``` ### Page Change Events @@ -413,17 +514,17 @@ $(document).ready -> ``` However, because Turbolinks overrides the normal page loading process, the -event that this relies on will not be fired. If you have code that looks like +event that this relies upon will not be fired. If you have code that looks like this, you must change your code to do this instead: ```coffeescript -$(document).on "page:change", -> +$(document).on "turbolinks:load", -> alert "page has loaded!" ``` For more details, including other events you can bind to, check out [the Turbolinks -README](https://github.com/rails/turbolinks/blob/master/README.md). +README](https://github.com/turbolinks/turbolinks/blob/master/README.md). Other Resources --------------- |