diff options
Diffstat (limited to 'guides/source')
-rw-r--r-- | guides/source/action_view_overview.textile | 24 | ||||
-rw-r--r-- | guides/source/active_record_querying.textile | 4 | ||||
-rw-r--r-- | guides/source/asset_pipeline.textile | 16 | ||||
-rw-r--r-- | guides/source/caching_with_rails.textile | 2 | ||||
-rw-r--r-- | guides/source/contributing_to_ruby_on_rails.textile | 2 | ||||
-rw-r--r-- | guides/source/engines.textile | 2 | ||||
-rw-r--r-- | guides/source/getting_started.textile | 14 | ||||
-rw-r--r-- | guides/source/i18n.textile | 26 | ||||
-rw-r--r-- | guides/source/layouts_and_rendering.textile | 10 | ||||
-rw-r--r-- | guides/source/migrations.textile | 17 | ||||
-rw-r--r-- | guides/source/rails_on_rack.textile | 123 |
11 files changed, 150 insertions, 90 deletions
diff --git a/guides/source/action_view_overview.textile b/guides/source/action_view_overview.textile index 42120e9bad..6649974eea 100644 --- a/guides/source/action_view_overview.textile +++ b/guides/source/action_view_overview.textile @@ -550,9 +550,9 @@ Register one or more JavaScript files to be included when symbol is passed to ja ActionView::Helpers::AssetTagHelper.register_javascript_expansion :monkey => ["head", "body", "tail"] javascript_include_tag :monkey # => - <script type="text/javascript" src="/javascripts/head.js"></script> - <script type="text/javascript" src="/javascripts/body.js"></script> - <script type="text/javascript" src="/javascripts/tail.js"></script> + <script src="/javascripts/head.js"></script> + <script src="/javascripts/body.js"></script> + <script src="/javascripts/tail.js"></script> </ruby> h5. register_stylesheet_expansion @@ -563,9 +563,9 @@ Register one or more stylesheet files to be included when symbol is passed to +s ActionView::Helpers::AssetTagHelper.register_stylesheet_expansion :monkey => ["head", "body", "tail"] stylesheet_link_tag :monkey # => - <link href="/stylesheets/head.css" media="screen" rel="stylesheet" type="text/css" /> - <link href="/stylesheets/body.css" media="screen" rel="stylesheet" type="text/css" /> - <link href="/stylesheets/tail.css" media="screen" rel="stylesheet" type="text/css" /> + <link href="/stylesheets/head.css" media="screen" rel="stylesheet" /> + <link href="/stylesheets/body.css" media="screen" rel="stylesheet" /> + <link href="/stylesheets/tail.css" media="screen" rel="stylesheet" /> </ruby> h5. auto_discovery_link_tag @@ -607,7 +607,7 @@ Returns an html script tag for each of the sources provided. You can pass in the <ruby> javascript_include_tag "common" # => - <script type="text/javascript" src="/javascripts/common.js"></script> + <script src="/javascripts/common.js"></script> </ruby> If the application does not use the asset pipeline, to include the jQuery JavaScript library in your application, pass +:defaults+ as the source. When using +:defaults+, if an +application.js+ file exists in your +public/javascripts+ directory, it will be included as well. @@ -626,7 +626,7 @@ You can also cache multiple JavaScript files into one file, which requires less <ruby> javascript_include_tag :all, :cache => true # => - <script type="text/javascript" src="/javascripts/all.js"></script> + <script src="/javascripts/all.js"></script> </ruby> h5. javascript_path @@ -651,7 +651,7 @@ Returns a stylesheet link tag for the sources specified as arguments. If you don <ruby> stylesheet_link_tag "application" # => - <link href="/stylesheets/application.css" media="screen" rel="stylesheet" type="text/css" /> + <link href="/stylesheets/application.css" media="screen" rel="stylesheet" /> </ruby> You can also include all styles in the stylesheet directory using :all as the source: @@ -664,7 +664,7 @@ You can also cache multiple stylesheets into one file, which requires less HTTP <ruby> stylesheet_link_tag :all, :cache => true - <link href="/stylesheets/all.css" media="screen" rel="stylesheet" type="text/css" /> + <link href="/stylesheets/all.css" media="screen" rel="stylesheet" /> </ruby> h5. stylesheet_path @@ -805,7 +805,7 @@ For example, let's say we have a standard application layout, but also a special <p>This is a special page.</p> <% content_for :special_script do %> - <script type="text/javascript">alert('Hello!')</script> + <script>alert('Hello!')</script> <% end %> </ruby> @@ -1501,7 +1501,7 @@ javascript_tag "alert('All is good')" </ruby> <html> -<script type="text/javascript"> +<script> //<![CDATA[ alert('All is good') //]]> diff --git a/guides/source/active_record_querying.textile b/guides/source/active_record_querying.textile index 14d0ba9b28..de55401c1f 100644 --- a/guides/source/active_record_querying.textile +++ b/guides/source/active_record_querying.textile @@ -695,7 +695,7 @@ Optimistic locking allows multiple users to access the same record for edits, an <strong>Optimistic locking column</strong> -In order to use optimistic locking, the table needs to have a column called +lock_version+. Each time the record is updated, Active Record increments the +lock_version+ column. If an update request is made with a lower value in the +lock_version+ field than is currently in the +lock_version+ column in the database, the update request will fail with an +ActiveRecord::StaleObjectError+. Example: +In order to use optimistic locking, the table needs to have a column called +lock_version+ of type integer. Each time the record is updated, Active Record increments the +lock_version+ column. If an update request is made with a lower value in the +lock_version+ field than is currently in the +lock_version+ column in the database, the update request will fail with an +ActiveRecord::StaleObjectError+. Example: <ruby> c1 = Client.find(1) @@ -1004,7 +1004,7 @@ Scopes are also chainable within scopes: <ruby> class Post < ActiveRecord::Base scope :published, -> { where(:published => true) } - scope :published_and_commented, -> { published.and(self.arel_table[:comments_count].gt(0)) } + scope :published_and_commented, -> { published.where("comments_count > 0") } end </ruby> diff --git a/guides/source/asset_pipeline.textile b/guides/source/asset_pipeline.textile index 464788f30f..d79eb01ab2 100644 --- a/guides/source/asset_pipeline.textile +++ b/guides/source/asset_pipeline.textile @@ -328,9 +328,9 @@ This manifest +app/assets/javascripts/application.js+: would generate this HTML: <html> -<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> +<script src="/assets/core.js?body=1"></script> +<script src="/assets/projects.js?body=1"></script> +<script src="/assets/tickets.js?body=1"></script> </html> The +body+ param is required by Sprockets. @@ -346,7 +346,7 @@ config.assets.debug = false When debug mode is off, Sprockets concatenates and runs the necessary preprocessors on all files. With debug mode turned off the manifest above would generate instead: <html> -<script src="/assets/application.js" type="text/javascript"></script> +<script src="/assets/application.js"></script> </html> 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. @@ -380,8 +380,8 @@ For example this: 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" /> +<script src="/assets/application-908e25f4bf641868d8683022a5b62f54.js"></script> +<link href="/assets/application-4dd5b109ee3439da54f5bdfd78a80473.css" media="screen" rel="stylesheet" /> </html> The fingerprinting behavior is controlled by the setting of +config.assets.digest+ setting in Rails (which defaults to +true+ for production and +false+ for everything else). @@ -409,9 +409,9 @@ cannot see application objects or methods. *Heroku requires this to be false.* WARNING: If you set +config.assets.initialize_on_precompile+ to false, be sure to test +rake assets:precompile+ locally before deploying. It may expose bugs where your assets reference application objects or methods, since those are still -in scope in development mode regardless of the value of this flag. Changing this flag also effects +in scope in development mode regardless of the value of this flag. Changing this flag also affects engines. Engines can define assets for precompilation as well. Since the complete environment is not loaded, -engines (or other gems) will not be loaded which can cause missing assets. +engines (or other gems) will not be loaded, which can cause missing assets. Capistrano (v2.8.0 and above) includes a recipe to handle this in deployment. Add the following line to +Capfile+: diff --git a/guides/source/caching_with_rails.textile b/guides/source/caching_with_rails.textile index 0e811a2527..12bc32f4e1 100644 --- a/guides/source/caching_with_rails.textile +++ b/guides/source/caching_with_rails.textile @@ -92,7 +92,7 @@ INFO: Page caching runs in an after filter. Thus, invalid requests won't generat h4. Action Caching -One of the issues with Page Caching is that you cannot use it for pages that require to restrict access somehow. This is where Action Caching comes in. Action Caching works like Page Caching except for the fact that the incoming web request does go from the webserver to the Rails stack and Action Pack so that before filters can be run on it before the cache is served. This allows authentication and other restriction to be run while still serving the result of the output from a cached copy. +Page Caching cannot be used for actions that have before filters - for example, pages that require authentication. This is where Action Caching comes in. Action Caching works like Page Caching except the incoming web request hits the Rails stack so that before filters can be run on it before the cache is served. This allows authentication and other restrictions to be run while still serving the result of the output from a cached copy. Clearing the cache works in a similar way to Page Caching, except you use +expire_action+ instead of +expire_page+. diff --git a/guides/source/contributing_to_ruby_on_rails.textile b/guides/source/contributing_to_ruby_on_rails.textile index d0dbb1555a..fbb3483dae 100644 --- a/guides/source/contributing_to_ruby_on_rails.textile +++ b/guides/source/contributing_to_ruby_on_rails.textile @@ -42,7 +42,7 @@ h4. Install Git Ruby on Rails uses git for source code control. The "git homepage":http://git-scm.com/ has installation instructions. There are a variety of resources on the net that will help you get familiar with git: -* "Everyday Git":http://www.kernel.org/pub/software/scm/git/docs/everyday.html will teach you just enough about git to get by. +* "Everyday Git":http://schacon.github.com/git/everyday.html will teach you just enough about git to get by. * The "PeepCode screencast":https://peepcode.com/products/git on git ($9) is easier to follow. * "GitHub":http://help.github.com offers links to a variety of git resources. * "Pro Git":http://progit.org/book/ is an entire book about git with a Creative Commons license. diff --git a/guides/source/engines.textile b/guides/source/engines.textile index 4993cae55a..36210aedb0 100644 --- a/guides/source/engines.textile +++ b/guides/source/engines.textile @@ -125,7 +125,7 @@ Also in the test directory is the +test/integration+ directory, where integratio 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. +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 diff --git a/guides/source/getting_started.textile b/guides/source/getting_started.textile index 0a85c84155..59b12b49e5 100644 --- a/guides/source/getting_started.textile +++ b/guides/source/getting_started.textile @@ -119,10 +119,10 @@ After you create the blog application, switch to its folder to continue work dir $ cd blog </shell> -The +rails new blog+ command we ran above created a folder in your working directory called <tt>blog</tt>. The <tt>blog</tt> directory has a number of auto-generated folders that make up the structure of a Rails application. Most of the work in this tutorial will happen in the <tt>app/</tt> folder, but here's a basic rundown on the function of each of the files and folders that Rails created by default: +The +rails new blog+ command we ran above created a folder in your working directory called <tt>blog</tt>. The <tt>blog</tt> directory has a number of auto-generated files and folders that make up the structure of a Rails application. Most of the work in this tutorial will happen in the <tt>app/</tt> folder, but here's a basic rundown on the function of each of the files and folders that Rails created by default: |_.File/Folder|_.Purpose| -|app/|Contains the controllers, models, views and assets for your application. You'll focus on this folder for the remainder of this guide.| +|app/|Contains the controllers, models, views, helpers, mailers and assets for your application. You'll focus on this folder for the remainder of this guide.| |config/|Configure your application's runtime rules, routes, database, and more. This is covered in more detail in "Configuring Rails Applications":configuring.html| |config.ru|Rack configuration for Rack based servers used to start the application.| |db/|Contains your current database schema, as well as the database migrations.| @@ -152,11 +152,11 @@ $ rails server TIP: Compiling CoffeeScript to JavaScript requires a JavaScript runtime and the absence of a runtime will give you an +execjs+ error. Usually Mac OS X and Windows come with a JavaScript runtime installed. Rails adds the +therubyracer+ gem to Gemfile in a commented line for new apps and you can uncomment if you need it. +therubyrhino+ is the recommended runtime for JRuby users and is added by default to Gemfile in apps generated under JRuby. You can investigate about all the supported runtimes at "ExecJS":https://github.com/sstephenson/execjs#readme. -This will fire up an instance of a webserver built into Ruby called WEBrick by default. To see your application in action, open a browser window and navigate to "http://localhost:3000":http://localhost:3000. You should see Rails' default information page: +This will fire up an instance of a webserver built into Ruby called WEBrick by default. To see your application in action, open a browser window and navigate to "http://localhost:3000":http://localhost:3000. You should see the Rails default information page: !images/rails_welcome.png(Welcome Aboard screenshot)! -TIP: To stop the web server, hit Ctrl+C in the terminal window where it's running. In development mode, Rails does not generally require you to stop the server; changes you make in files will be automatically picked up by the server. +TIP: To stop the web server, hit Ctrl+C in the terminal window where it's running. In development mode, Rails does not generally require you to restart the server; changes you make in files will be automatically picked up by the server. The "Welcome Aboard" page is the _smoke test_ for a new Rails application: it makes sure that you have your software configured correctly enough to serve a page. You can also click on the _About your application’s environment_ link to see a summary of your application's environment. @@ -284,13 +284,13 @@ Missing template posts/new, application/new with {:locale=>[:en], :formats=>[:ht That's quite a lot of text! Let's quickly go through and understand what each part of it does. -The first part identifies what template is missing. In this case, it's the +posts/new+ template. Rails will first look for this template. If it can't find it, then it will attempt to load a template called +application/new+. It looks for one here because the +PostsController+ inherits from +ApplicationController+. +The first part identifies what template is missing. In this case, it's the +posts/new+ template. Rails will first look for this template. If not found, then it will attempt to load a template called +application/new+. It looks for one here because the +PostsController+ inherits from +ApplicationController+. -The next part of the message contains a hash. The +:locale+ key in this hash simply indicates what spoken language template should be retrieved. By default, this is the English -- or "en" -- template. The next key, +:formats+ shows what formats of template Rails is after. The default is +:html+, and so Rails is looking for an HTML template. The final key, +:handlers+, is telling us what _template handlers_ could be used to render our template. +:erb+ is most commonly used for HTML templates, +:builder+ is used for XML templates, and +:coffee+ uses CoffeeScript to build JavaScript templates. +The next part of the message contains a hash. The +:locale+ key in this hash simply indicates what spoken language template should be retrieved. By default, this is the English -- or "en" -- template. The next key, +:formats+ specifies the format of template to be served in response . The default format is +:html+, and so Rails is looking for an HTML template. The final key, +:handlers+, is telling us what _template handlers_ could be used to render our template. +:erb+ is most commonly used for HTML templates, +:builder+ is used for XML templates, and +:coffee+ uses CoffeeScript to build JavaScript templates. The final part of this message tells us where Rails has looked for the templates. Templates within a basic Rails application like this are kept in a single location, but in more complex applications it could be many different paths. -The simplest template that would work in this case would be one located at +app/views/posts/new.html.erb+. The extension of this file name is key: the first extension is the _format_ of the template, and the second extension is the _handler_ that will be used. Rails is attempting to find a template called +posts/new+ within +app/views+ for the application. The format for this template can only be +html+ and the handler must be one of +erb+, +builder+ or +coffee+. Because you want to create a new HTML form, you will be using the +ERB+ language. Therefore the file should be called +posts/new.html.erb+ and be located inside the +app/views+ directory of the application. +The simplest template that would work in this case would be one located at +app/views/posts/new.html.erb+. The extension of this file name is key: the first extension is the _format_ of the template, and the second extension is the _handler_ that will be used. Rails is attempting to find a template called +posts/new+ within +app/views+ for the application. The format for this template can only be +html+ and the handler must be one of +erb+, +builder+ or +coffee+. Because you want to create a new HTML form, you will be using the +ERB+ language. Therefore the file should be called +posts/new.html.erb+ and needs to be located inside the +app/views+ directory of the application. Go ahead now and create a new file at +app/views/posts/new.html.erb+ and write this content in it: diff --git a/guides/source/i18n.textile b/guides/source/i18n.textile index 320f1e9d20..6179694c40 100644 --- a/guides/source/i18n.textile +++ b/guides/source/i18n.textile @@ -866,19 +866,35 @@ The I18n API will catch all of these exceptions when they are thrown in the back The reason for this is that during development you'd usually want your views to still render even though a translation is missing. -In other contexts you might want to change this behaviour, though. E.g. the default exception handling does not allow to catch missing translations during automated tests easily. For this purpose a different exception handler can be specified. The specified exception handler must be a method on the I18n module: +In other contexts you might want to change this behaviour, though. E.g. the default exception handling does not allow to catch missing translations during automated tests easily. For this purpose a different exception handler can be specified. The specified exception handler must be a method on the I18n module or a class with +#call+ method: <ruby> module I18n - def self.just_raise_that_exception(*args) - raise args.first + class JustRaiseExceptionHandler < ExceptionHandler + def call(exception, locale, key, options) + if exception.is_a?(MissingTranslation) + raise exception.to_exception + else + super + end + end end end -I18n.exception_handler = :just_raise_that_exception +I18n.exception_handler = I18n::JustRaiseExceptionHandler.new </ruby> -This would re-raise all caught exceptions including +MissingTranslationData+. +This would re-raise only the +MissingTranslationData+ exception, passing all other input to the default exception handler. + +However, if you are using +I18n::Backend::Pluralization+ this handler will also raise +I18n::MissingTranslationData: translation missing: en.i18n.plural.rule+ exception that should normally be ignored to fall back to the default pluralization rule for English locale. To avoid this you may use additional check for translation key: + +<ruby> +if exception.is_a?(MissingTranslation) && key.to_s != 'i18n.plural.rule' + raise exception.to_exception +else + super +end +</ruby> Another example where the default behaviour is less desirable is the Rails TranslationHelper which provides the method +#t+ (as well as +#translate+). When a +MissingTranslationData+ exception occurs in this context, the helper wraps the message into a span with the CSS class +translation_missing+. diff --git a/guides/source/layouts_and_rendering.textile b/guides/source/layouts_and_rendering.textile index 7c7fc7044c..c2bba56581 100644 --- a/guides/source/layouts_and_rendering.textile +++ b/guides/source/layouts_and_rendering.textile @@ -686,7 +686,7 @@ You can specify a full path relative to the document root, or a URL, if you pref Rails will then output a +script+ tag such as this: <html> -<script src='/assets/main.js' type="text/javascript"></script> +<script src='/assets/main.js'></script> </html> The request to this asset is then served by the Sprockets gem. @@ -718,8 +718,8 @@ If the application does not use the asset pipeline, the +:defaults+ option loads Outputting +script+ tags such as this: <html> -<script src="/javascripts/jquery.js" type="text/javascript"></script> -<script src="/javascripts/jquery_ujs.js" type="text/javascript"></script> +<script src="/javascripts/jquery.js"></script> +<script src="/javascripts/jquery_ujs.js"></script> </html> These two files for jQuery, +jquery.js+ and +jquery_ujs.js+ must be placed inside +public/javascripts+ if the application doesn't use the asset pipeline. These files can be downloaded from the "jquery-rails repository on GitHub":https://github.com/indirect/jquery-rails/tree/master/vendor/assets/javascripts @@ -805,7 +805,7 @@ To include +http://example.com/main.css+: <%= stylesheet_link_tag "http://example.com/main.css" %> </erb> -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+): +By default, the +stylesheet_link_tag+ creates links with +media="screen" rel="stylesheet"+. You can override any of these defaults by specifying an appropriate option (+:media+, +:rel+): <erb> <%= stylesheet_link_tag "main_print", :media => "print" %> @@ -1206,7 +1206,7 @@ Suppose you have the following +ApplicationController+ layout: <head> <title><%= @page_title or 'Page Title' %></title> <%= stylesheet_link_tag 'layout' %> - <style type="text/css"><%= yield :stylesheets %></style> + <style><%= yield :stylesheets %></style> </head> <body> <div id="top_menu">Top menu items here</div> diff --git a/guides/source/migrations.textile b/guides/source/migrations.textile index c11f8e221b..f663496854 100644 --- a/guides/source/migrations.textile +++ b/guides/source/migrations.textile @@ -51,7 +51,7 @@ end This migration adds a table called +products+ with a string column called +name+ and a text column called +description+. A primary key column called +id+ will -also be added, however since this is the default we do not need to ask for this. +also be added, however since this is the default we do not need to explicitly specify it. The timestamp columns +created_at+ and +updated_at+ which Active Record populates automatically will also be added. Reversing this migration is as simple as dropping the table. @@ -65,7 +65,7 @@ class AddReceiveNewsletterToUsers < ActiveRecord::Migration change_table :users do |t| t.boolean :receive_newsletter, :default => false end - User.update_all ["receive_newsletter = ?", true] + User.update_all :receive_newsletter => true end def down @@ -497,7 +497,7 @@ and h4. Using the +change+ Method The +change+ method removes the need to write both +up+ and +down+ methods in -those cases that Rails know how to revert the changes automatically. Currently, +those cases that Rails knows how to revert the changes automatically. Currently, the +change+ method supports only these migration definitions: * +add_column+ @@ -635,10 +635,9 @@ example, $ rake db:migrate:up VERSION=20080906120000 </shell> -will run the +up+ method from the 20080906120000 migration. These tasks still -check whether the migration has already run, so for example +db:migrate:up -VERSION=20080906120000+ will do nothing if Active Record believes that -20080906120000 has already been run. +will run the +up+ method from the 20080906120000 migration. This task will first +check whether the migration is already performed and will do nothing if Active Record believes +that it has already been run. h4. Changing the output of running migrations @@ -728,7 +727,7 @@ class AddFlagToProduct < ActiveRecord::Migration def change add_column :products, :flag, :boolean Product.all.each do |product| - product.update_attributes!(:flag => 'false') + product.update_attributes!(:flag => false) end end end @@ -804,7 +803,7 @@ class AddFlagToProduct < ActiveRecord::Migration end def change - add_column :products, :flag, :integer + add_column :products, :flag, :boolean Product.reset_column_information Product.all.each do |product| product.update_attributes!(:flag => false) diff --git a/guides/source/rails_on_rack.textile b/guides/source/rails_on_rack.textile index 9526526bc7..ff862273fd 100644 --- a/guides/source/rails_on_rack.textile +++ b/guides/source/rails_on_rack.textile @@ -91,13 +91,15 @@ For a freshly generated Rails application, this might produce something like: <ruby> use ActionDispatch::Static use Rack::Lock -use ActiveSupport::Cache::Strategy::LocalCache +use #<ActiveSupport::Cache::Strategy::LocalCache::Middleware:0x000000029a0838> use Rack::Runtime +use Rack::MethodOverride +use ActionDispatch::RequestId use Rails::Rack::Logger use ActionDispatch::ShowExceptions use ActionDispatch::DebugExceptions use ActionDispatch::RemoteIp -use Rack::Sendfile +use ActionDispatch::Reloader use ActionDispatch::Callbacks use ActiveRecord::ConnectionAdapters::ConnectionManagement use ActiveRecord::QueryCache @@ -105,8 +107,9 @@ use ActionDispatch::Cookies use ActionDispatch::Session::CookieStore use ActionDispatch::Flash use ActionDispatch::ParamsParser -use Rack::MethodOverride use ActionDispatch::Head +use Rack::ConditionalGet +use Rack::ETag use ActionDispatch::BestStandardsSupport run Blog::Application.routes </ruby> @@ -145,62 +148,104 @@ You can swap an existing middleware in the middleware stack using +config.middle <ruby> # config/application.rb -# Replace ActionController::Failsafe with Lifo::Failsafe -config.middleware.swap ActionController::Failsafe, Lifo::Failsafe +# Replace ActionDispatch::ShowExceptions with Lifo::ShowExceptions +config.middleware.swap ActionDispatch::ShowExceptions, Lifo::ShowExceptions </ruby> h5. Middleware Stack is an Array The middleware stack behaves just like a normal +Array+. You can use any +Array+ methods to insert, reorder, or remove items from the stack. Methods described in the section above are just convenience methods. -For example, the following removes the middleware matching the supplied class name: +Append following lines to your application configuration: <ruby> -config.middleware.delete(middleware) +# config/application.rb +config.middleware.delete "Rack::Lock" </ruby> +And now if you inspect the middleware stack, you'll find that +Rack::Lock+ will not be part of it. + +<shell> +$ rake middleware +(in /Users/lifo/Rails/blog) +use ActionDispatch::Static +use #<ActiveSupport::Cache::Strategy::LocalCache::Middleware:0x00000001c304c8> +use Rack::Runtime +... +run Myapp::Application.routes +</shell> + h4. Internal Middleware Stack -Much of Action Controller's functionality is implemented as Middlewares. The following table explains the purpose of each of them: +Much of Action Controller's functionality is implemented as Middlewares. The following list explains the purpose of each of them: -|_.Middleware|_.Purpose| -|+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.| -|+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.| + *+ActionDispatch::Static+* +* Used to serve static assets. Disabled if <tt>config.serve_static_assets</tt> is true. -TIP: It's possible to use any of the above middlewares in your custom Rack stack. + *+Rack::Lock+* +* Sets <tt>env["rack.multithread"]</tt> flag to +true+ and wraps the application within a Mutex. -h4. Customizing Internal Middleware Stack + *+ActiveSupport::Cache::Strategy::LocalCache::Middleware+* +* Used for memory caching. This cache is not thread safe. -It's possible to replace the entire middleware stack with a custom stack using <tt>ActionController::Dispatcher.middleware=</tt>. + *+Rack::Runtime+* +* Sets an X-Runtime header, containing the time (in seconds) taken to execute the request. -Put the following in an initializer: + *+Rack::MethodOverride+* +* Allows the method to be overridden if <tt>params[:_method]</tt> is set. This is the middleware which supports the PUT and DELETE HTTP method types. -<ruby> -# config/initializers/stack.rb -ActionController::Dispatcher.middleware = ActionController::MiddlewareStack.new do |m| - m.use ActionController::Failsafe - m.use ActiveRecord::QueryCache - m.use Rack::Head -end -</ruby> + *+ActionDispatch::RequestId+* +* Makes a unique +X-Request-Id+ header available to the response and enables the <tt>ActionDispatch::Request#uuid</tt> method. -And now inspecting the middleware stack: + *+Rails::Rack::Logger+* +* Notifies the logs that the request has began. After request is complete, flushes all the logs. -<shell> -$ rake middleware -(in /Users/lifo/Rails/blog) -use ActionController::Failsafe -use ActiveRecord::QueryCache -use Rack::Head -run ActionController::Dispatcher.new -</shell> + *+ActionDispatch::ShowExceptions+* +* Rescues any exception returned by the application and calls an exceptions app that will wrap it in a format for the end user. + + *+ActionDispatch::DebugExceptions+* +* Responsible for logging exceptions and showing a debugging page in case the request is local. + + *+ActionDispatch::RemoteIp+* +* Checks for IP spoofing attacks. + + *+ActionDispatch::Reloader+* +* Provides prepare and cleanup callbacks, intended to assist with code reloading during development. + + *+ActionDispatch::Callbacks+* +* Runs the prepare callbacks before serving the request. + + *+ActiveRecord::ConnectionAdapters::ConnectionManagement+* +* Cleans active connections after each request, unless the <tt>rack.test</tt> key in the request environment is set to +true+. + + *+ActiveRecord::QueryCache+* +* Enables the Active Record query cache. + + *+ActionDispatch::Cookies+* +* Sets cookies for the request. + + *+ActionDispatch::Session::CookieStore+* +* Responsible for storing the session in cookies. + + *+ActionDispatch::Flash+* +* Sets up the flash keys. Only available if <tt>config.action_controller.session_store</tt> is set to a value. + + *+ActionDispatch::ParamsParser+* +* Parses out parameters from the request into <tt>params</tt>. + + *+ActionDispatch::Head+* +* Converts HEAD requests to +GET+ requests and serves them as so. + + *+Rack::ConditionalGet+* +* Adds support for "Conditional +GET+" so that server responds with nothing if page wasn't changed. + + *+Rack::ETag+* +* Adds ETag header on all String bodies. ETags are used to validate cache. + + *+ActionDispatch::BestStandardsSupport+* +* Enables “best standards support” so that IE8 renders some elements correctly. + +TIP: It's possible to use any of the above middlewares in your custom Rack stack. h4. Using Rack Builder |