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Diffstat (limited to 'railties/guides/source/configuring.textile')
| -rw-r--r-- | railties/guides/source/configuring.textile | 105 |
1 files changed, 101 insertions, 4 deletions
diff --git a/railties/guides/source/configuring.textile b/railties/guides/source/configuring.textile index 837b3b563c..0236e72529 100644 --- a/railties/guides/source/configuring.textile +++ b/railties/guides/source/configuring.textile @@ -362,7 +362,6 @@ There are a few configuration options available in Active Support: * +ActiveSupport::Logger.silencer+ is set to +false+ to disable the ability to silence logging in a block. The default is +true+. - h3. Rails Environment Settings Some parts of Rails can also be configured externally by supplying environment variables. The following environment variables are recognized by various parts of Rails: @@ -380,7 +379,7 @@ h3. Initialization events Rails has 5 initialization events which can be hooked into (listed in order that they are ran): * +before_configuration+: This is run as soon as the application constant inherits from +Rails::Application+. The +config+ calls are evaluated before this happens. -* +before_initialize+: This is run directly before the initialization process of the application occurs. +* +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. * +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+ enviroment. * +after_initialize+: Run directly after the initialization of the application, but before the application initializers are run. @@ -398,7 +397,6 @@ Rails has several initializers that run on startup that are all defined by using end </ruby> - The +initializer+ method takes three arguments with the first being the name for the initializer and the second being an options hash (not shown here) and the third being a block. The +:before+ key in the options hash can be specified to specify which initializer this new initializer must run before, and the +:after+ key will specify which initializer to run this initializer _after_. Initializers defined using the +initializer+ method will be ran in the order they are defined in, with the exception of ones that use the +:before+ or +:after+ methods. @@ -407,6 +405,104 @@ WARNING: You may put your initializer before or after any other initializer in t The block's argument of the +initialize+ is the instance of the application itself, and so we can access the configuration on it by using the +config+ method as this initializer does. +Because +Rails::Application+ inherits from +Rails::Railtie+ (indirectly), you can use the +initializer+ method in +config/application.rb+ to define initializers for the application. + +Below is a comprehensive list of all the initializers found in Rails in the order that they are defined (and therefore run in, unless otherwise stated). + +h4. +load_environment_hook+ + +Serves as a placeholder so that +:load_environment_config+ can be defined to run before it. + +h4. +load_active_support+ + +Requires +active_support/dependencies+ which sets up the basis for Active Support. Optionally requires +active_support/all+ if +config.active_support.bare+ is un-truthful, which is the default. + +h4. +preload_frameworks+ + +Will load all autoload dependencies of Rails automatically if +config.preload_frameworks+ is +true+ or "truthful". By default this configuration option is disabled. In Rails, when internal classes are referenced for the first time they are autoloaded. +:preload_frameworks+ loads all of this at once on initialization. + +h4. +initialize_logger+ + +Initializes the logger (an +ActiveSupport::BufferedLogger+ object) for the application and makes it accessible at +Rails.logger+, providing that there's no initializer inserted before this point that has defined +Rails.logger+. + +h4. +initialize_cache+ + +If +RAILS_CACHE+ isn't yet set, initializes the cache by referencing the value in +config.cache_store+ and stores the outcome as +RAILS_CACHE+. If this object responds to the +middleware+ method, its middleware is inserted before +Rack::Runtime+ in the middleware stack. + +h4. +set_clear_dependencies_hook+ + +Provides a hook for +active_record.set_dispatch_hooks+ to use, which will run before this initializer. + +This initializer -- which runs only if +cache_classes+ is set to +false+ -- uses +ActionDispatch::Callbacks.after+ to remove the constants which have been referenced during the request from the object space so that they will be reloaded during the following request. + +h4. +initialize_dependency_mechanism+ + +If +config.cache_classes+ is set to +true+, configures +ActiveSupport::Dependencies.mechanism+ to +require+ dependencies rather than +load+ them. + +h4. +bootstrap_hook+ + +Runs all configured +before_initialize+ blocks. + +h4. +i18n.callbacks+ + +In the development environment, sets up a +to_prepare+ callback which will call +I18n.reload!+ if any of the locales have changed since the last request. In production mode this callback will only run on the first request. + +h4. +active_support.initialize_whiny_nils+ + +Will require +active_support/whiny_nil+ if +config.whiny_nil+ is set to +true+. This file will output errors such as: + +<text> + Called id for nil, which would mistakenly be 4 -- if you really wanted the id of nil, use object_id +</text> + +And: + +<text> + You have a nil object when you didn't expect it! + You might have expected an instance of Array. + The error occurred while evaluating nil.each +</text> + +h4. +active_support.deprecation_behavior+ + +Sets up deprecation reporting for environments, defaulting to +log+ for development, +notify+ for production and +stderr+ for test. If a value isn't set for +config.active_support.deprecation+ then this initializer will prompt the user to configure this line in the current environment's +config/environments+ file. + +h4. +active_support.initialize_time_zone+ + +Sets the default time zone for the application based off the +config.time_zone+ setting, which defaults to "UTC". + +h4. +action_dispatch.configure+ + +Configures the +ActionDispatch::Http::URL.tld_length+ to be set to the value of +config.action_dispatch.tld_length+. + +h4. +action_view.cache_asset_ids+ + +Will set +ActionView::Helpers::AssetTagHelper::AssetPaths.cache_asset_ids+ to +false+ when Active Support loads, but only if +config.cache_classes+ is too. + +h4. +action_view.javascript_expansions+ + +Registers the expansions set up by +config.action_view.javascript_expansions+ and +config.action_view.stylesheet_expansions+ to be recognised by Action View and therefore usable in the views. + +h4. +action_view.set_configs+ + +Sets up Action View by using the settings in +config.action_view+ by +send+'ing the method names as setters to +ActionView::Base+ and passing the values through. + +h4. +action_controller.logger+ + +Sets +ActionController::Base.logger+ -- if it's not already set -- to +Rails.logger+. + +h4. +action_controller.initialize_framework_caches+ + +Sets +ActionController::Base.cache_store+ -- if it's not already set -- to +RAILS_CACHE+. + +h4. +action_controller.set_configs+ + +Sets up Action View by using the settings in +config.action_controller+ by +send+'ing the method names as setters to +ActionController::Base+ and passing the values through. + +h4 +active_record.initialize_timezone+ + +Sets +ActiveRecord::Base.time_zone_aware_attributes+ to true, as well as setting +ActiveRecord::Base.default_timezone+ to UTC. + h4. Initializer files After loading the framework and any gems and plugins in your application, Rails turns to loading initialization code from +config/initializers+. The files in this directory can be used to hold configuration settings that should be made after all of the frameworks and plugins are loaded. @@ -417,7 +513,8 @@ TIP: If you have any ordering dependency in your initializers, you can control t h3. Changelog -* November 26, 2010: Removed all config settings not available in Rails 3 (Ryan Bigg) +* 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 |