@@ -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.
Rails maintains an official plugin, DynamicForm, 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.
"DynamicForm":https://github.com/joelmoss/dynamic_form provides helpers to display the error messages of your models in your view templates.
You can install it as a gem by adding this line to your Gemfile:
<ruby>
gem "dynamic_form"
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@@ -986,15 +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 they are registered simply by defining them as regular methods with predefined names. 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, which would otherwise significantly slow 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.
@@ -40,6 +40,8 @@ Rails will use that particular setting to configure Active Record.
h4. Rails General Configuration
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:
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
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@@ -111,7 +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
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@@ -130,7 +130,7 @@ The gem +sqlite3-ruby+ does not belong to the "db" group indeed, if you followed
@@ -506,6 +506,10 @@ 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:
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@@ -542,6 +546,14 @@ Go ahead and try to create a new post. You will see that it works exactly in the
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.
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+
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@@ -575,7 +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+.
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@@ -598,11 +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
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+
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@@ -682,7 +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+.
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@@ -698,7 +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.
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:
@@ -620,7 +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.
