Class: ActionController::Metal

Relationships & Source Files
Extension / Inclusion / Inheritance Descendants
Subclasses: Base, Middleware, Rails::ApplicationController, Rails::InfoController, Rails::MailersController, Rails::WelcomeController, ActionView::TestCase::TestController
Super Chains via Extension / Inclusion / Inheritance
Class Chain: self, ::AbstractController::Base, ::ActiveSupport::DescendantsTracker
Instance Chain: self, ::AbstractController::Base, ::ActiveSupport::Configurable
Inherits:	AbstractController::Base ::Object AbstractController::Base ActionController::Metal
Defined in:	actionpack/lib/action_controller/metal.rb

Overview

Metal is the simplest possible controller, providing a valid ::Rack interface without the additional niceties provided by Base.

A sample metal controller might look like this:

class HelloController < ActionController::Metal
  def index
    self.response_body = "Hello World!"
  end
end

And then to route requests to your metal controller, you would add something like this to config/routes.rb:

get 'hello', to: HelloController.action(:index)

The .action method returns a valid ::Rack application for the Rails router to dispatch to.

Rendering Helpers

Metal by default provides no utilities for rendering views, partials, or other responses aside from explicitly calling of #response_body=, #content_type=, and #status=. To add the render helpers you're used to having in a normal controller, you can do the following:

class HelloController < ActionController::Metal
  include AbstractController::Rendering
  include ActionView::Layouts
  append_view_path "#{Rails.root}/app/views"

  def index
    render "hello/index"
  end
end

Redirection Helpers

To add redirection helpers to your metal controller, do the following:

class HelloController < ActionController::Metal
  include ActionController::Redirecting
  include Rails.application.routes.url_helpers

  def index
    redirect_to root_url
  end
end

Other Helpers

You can refer to the modules included in Base to see other features you can bring into your metal controller.

::AbstractController::Base - Inherited

.abstract?	Alias for AbstractController::Base.abstract.
.supports_path?	Returns true if the given controller is capable of rendering a path.

Class Method Summary

.action(name, klass = ActionDispatch::Request)

Returns a ::Rack endpoint for the given action name.
.call(env)

Makes the controller a ::Rack endpoint that runs the action in the given #env's action_dispatch.request.path_parameters key.
.controller_name

Returns the last part of the controller's name, underscored, without the ending Controller.
.middleware

Alias for .middleware_stack.
.new ⇒ Metal (also: .build) constructor
.use(*args, &block)

Pushes the given ::Rack middleware and its arguments to the bottom of the middleware stack.

::AbstractController::Base - Inherited

.abstract,
.abstract!	Define a controller as abstract.
.action_methods	A list of method names that should be considered actions.
.clear_action_methods!	action_methods are cached and there is sometimes need to refresh them.
.controller_path	Returns the full controller name, underscored, without the ending Controller.
.hidden_actions	The list of hidden actions.
.internal_methods	A list of all internal methods for a controller.
.method_added	Refresh the cached action_methods when a new action_method is added.

::ActiveSupport::DescendantsTracker - Extended

descendants, direct_descendants, inherited

Instance Attribute Summary

#content_type rw
#content_type=(type) rw

Basic implementations for content_type=, location=, and headers are provided to reduce the dependency on the RackDelegation module in Renderer and Redirector.
#env rw
#env=(value) rw
#headers rw

The details below can be overridden to support a specific Request and Response object.
#location rw
#location=(url) rw
#middleware_stack rw
#middleware_stack? ⇒ Boolean rw
#params rw
#params=(val) rw
#performed? ⇒ Boolean readonly

Tests if render or redirect has already happened.
#request rw

The details below can be overridden to support a specific Request and Response object.
#response rw

The details below can be overridden to support a specific Request and Response object.
#response_body=(body) writeonly
#session readonly
#status (also: #response_code) rw
#status=(status) rw

::AbstractController::Base - Inherited

#action_name, #formats, #response_body

Instance Method Summary

#controller_name

Delegates to the class' controller_name.
#url_for(string)

Basic url_for that can be overridden for more robust functionality.

::AbstractController::Base - Inherited

#action_methods	Delegates to the class' `#action_methods`
#available_action?	Returns true if a method for the action is available and can be dispatched, false otherwise.
#controller_path	Delegates to the class' `#controller_path`
#process	Calls the action going through the entire action dispatch stack.

::ActiveSupport::Configurable - Included

#config

Reads and writes attributes from a configuration OrderedHash.

Constructor Details

.new ⇒ `Metal` Also known as: .build

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 131


def initialize
  @_headers = {"Content-Type" => "text/html"}
  @_status = 200
  @_request = nil
  @_response = nil
  @_routes = nil
  super
end

Class Attribute Details

.middleware_stack (rw)

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 204


class_attribute :middleware_stack

.middleware_stack? ⇒ `Boolean` (rw)

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 204


class_attribute :middleware_stack

Class Method Details

.action(name, klass = ActionDispatch::Request)

Returns a ::Rack endpoint for the given action name.

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 231


def self.action(name, klass = ActionDispatch::Request)
  if middleware_stack.any?
    middleware_stack.build(name) do |env|
      new.dispatch(name, klass.new(env))
    end
  else
    lambda { |env| new.dispatch(name, klass.new(env)) }
  end
end

.call(env)

Makes the controller a ::Rack endpoint that runs the action in the given #env's action_dispatch.request.path_parameters key.

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 225


def self.call(env)
  req = ActionDispatch::Request.new env
  action(req.path_parameters[:action]).call(env)
end

.controller_name

Returns the last part of the controller's name, underscored, without the ending Controller. For instance, PostsController returns posts. Namespaces are left out, so Admin::PostsController returns posts as well.

Returns

string

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 113


def self.controller_name
  @controller_name ||= name.demodulize.sub(/Controller$/, '').underscore
end

.middleware

Alias for .middleware_stack.

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 219


def self.middleware
  middleware_stack
end

.use(*args, &block)

Pushes the given ::Rack middleware and its arguments to the bottom of the middleware stack.

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 214


def self.use(*args, &block)
  middleware_stack.use(*args, &block)
end

Instance Attribute Details

#content_type (rw)

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 156


def content_type
  headers["Content-Type"]
end

#content_type=(type) (rw)

Basic implementations for content_type=, location=, and headers are provided to reduce the dependency on the RackDelegation module in Renderer and Redirector.

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 152


def content_type=(type)
  headers["Content-Type"] = type.to_s
end

#env (rw)

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 103


def env
  @_env ||= {}
end

#env=(value) (rw)

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 101


attr_internal_writer :env

#headers (rw)

The details below can be overridden to support a specific Request and Response object. The default Base implementation includes RackDelegation, which makes a request and response object available. You might wish to control the environment and response manually for performance reasons.

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 128


attr_internal :headers, :response, :request

#location (rw)

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 160


def location
  headers["Location"]
end

#location=(url) (rw)

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 164


def location=(url)
  headers["Location"] = url
end

#middleware_stack (rw)

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 204


class_attribute :middleware_stack

#middleware_stack? ⇒ `Boolean` (rw)

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 204


class_attribute :middleware_stack

#params (rw)

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 140


def params
  @_params ||= request.parameters
end

#params=(val) (rw)

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 144


def params=(val)
  @_params = val
end

#performed? ⇒ `Boolean` (readonly)

Tests if render or redirect has already happened.

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 188


def performed?
  response_body || (response && response.committed?)
end

#request (rw)

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 128


attr_internal :headers, :response, :request

#response (rw)

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 128


attr_internal :headers, :response, :request

#response_body=(body) (writeonly)

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 182


def response_body=(body)
  body = [body] unless body.nil? || body.respond_to?(:each)
  super
end

#session (readonly)

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 129


delegate :session, :to => "@_request"

#status (rw) Also known as: #response_code

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 173


def status
  @_status
end

#status=(status) (rw)

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 178


def status=(status)
  @_status = Rack::Utils.status_code(status)
end

Instance Method Details

#controller_name

Delegates to the class' controller_name

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 118


def controller_name
  self.class.controller_name
end

#url_for(string)

Basic url_for that can be overridden for more robust functionality

[ GitHub ]

# File 'actionpack/lib/action_controller/metal.rb', line 169


def url_for(string)
  string
end

Class: ActionController::Metal

Overview

Rendering Helpers

Redirection Helpers

Other Helpers

Class Attribute Summary

::AbstractController::Base - Inherited

Class Method Summary

::AbstractController::Base - Inherited

::ActiveSupport::DescendantsTracker - Extended

Instance Attribute Summary

::AbstractController::Base - Inherited

Instance Method Summary

::AbstractController::Base - Inherited

::ActiveSupport::Configurable - Included

Constructor Details

.new ⇒ Metal Also known as: .build

Class Attribute Details

.middleware_stack (rw)

.middleware_stack? ⇒ Boolean (rw)

Class Method Details

.action(name, klass = ActionDispatch::Request)

.call(env)

.controller_name

Returns

.middleware

.use(*args, &block)

Instance Attribute Details

#content_type (rw)

#content_type=(type) (rw)

#env (rw)

#env=(value) (rw)

#headers (rw)

#location (rw)

#location=(url) (rw)

#middleware_stack (rw)

#middleware_stack? ⇒ Boolean (rw)

#params (rw)

#params=(val) (rw)

#performed? ⇒ Boolean (readonly)

#request (rw)

#response (rw)

#response_body=(body) (writeonly)

#session (readonly)

#status (rw) Also known as: #response_code

#status=(status) (rw)

Instance Method Details

#controller_name

#url_for(string)

.new ⇒ `Metal` Also known as: .build

.middleware_stack? ⇒ `Boolean` (rw)

#middleware_stack? ⇒ `Boolean` (rw)

#performed? ⇒ `Boolean` (readonly)