Class: ActionController::Metal

Inherits:
AbstractController::Base show all
Includes:
Testing::Functional
Defined in:
lib/action_controller/metal.rb,
lib/action_controller/test_case.rb

Overview

# Action Controller Metal

‘ActionController::Metal` is the simplest possible controller, providing a valid Rack interface without the additional niceties provided by ActionController::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

By default, ‘ActionController::Metal` provides no utilities for rendering views, partials, or other responses aside from some low-level setters such as #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 ActionController::Base to see other features you can bring into your metal controller.

Direct Known Subclasses

API, Base

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Testing::Functional

#clear_instance_variables_between_requests, #recycle!

Methods inherited from AbstractController::Base

abstract!, action_methods, #action_methods, #action_name, #available_action?, clear_action_methods!, controller_path, #controller_path, eager_load!, #formats, #inspect, internal_methods, method_added, #process, #response_body, supports_path?

Constructor Details

#initialize ⇒ Metal

Returns a new instance of Metal.



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# File 'lib/action_controller/metal.rb', line 210

def initialize
  @_request = nil
  @_response = nil
  @_response_body = nil
  @_routes = nil
  @_params = nil
  super
end

Class Method Details

.action(name) ⇒ Object

Returns a Rack endpoint for the given action name.



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# File 'lib/action_controller/metal.rb', line 315

def self.action(name)
  app = lambda { |env|
    req = ActionDispatch::Request.new(env)
    res = make_response! req
    new.dispatch(name, req, res)
  }

  if middleware_stack.any?
    middleware_stack.build(name, app)
  else
    app
  end
end

.action_encoding_template(action) ⇒ Object

:nodoc:



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

def self.action_encoding_template(action) # :nodoc:
  false
end

.controller_name ⇒ Object

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`



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# File 'lib/action_controller/metal.rb', line 130

def self.controller_name
  @controller_name ||= (name.demodulize.delete_suffix("Controller").underscore unless anonymous?)
end

.dispatch(name, req, res) ⇒ Object

Direct dispatch to the controller. Instantiates the controller, then executes the action named ‘name`.



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# File 'lib/action_controller/metal.rb', line 331

def self.dispatch(name, req, res)
  if middleware_stack.any?
    middleware_stack.build(name) { |env| new.dispatch(name, req, res) }.call req.env
  else
    new.dispatch(name, req, res)
  end
end

.make_response!(request) ⇒ Object 



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# File 'lib/action_controller/metal.rb', line 134

def self.make_response!(request)
  ActionDispatch::Response.new.tap do |res|
    res.request = request
  end
end

.middleware ⇒ Object

The middleware stack used by this controller.

By default uses a variation of ActionDispatch::MiddlewareStack which allows for the following syntax:

class PostsController < ApplicationController
  use AuthenticationMiddleware, except: [:index, :show]
end

Read more about [Rails middleware stack] (guides.rubyonrails.org/rails_on_rack.html#action-dispatcher-middleware-stack) in the guides.



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# File 'lib/action_controller/metal.rb', line 310

def self.middleware
  middleware_stack
end

.use ⇒ Object

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



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# File 'lib/action_controller/metal.rb', line 293

def use(...)
  middleware_stack.use(...)
end

Instance Method Details

#content_type ⇒ Object

Delegates to ActionDispatch::Response#content_type



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

delegate :content_type, to: "@_response"

#content_type= ⇒ Object

Delegates to ActionDispatch::Response#content_type=



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# File 'lib/action_controller/metal.rb', line 192

delegate :content_type=, to: "@_response"

#controller_name ⇒ Object

Delegates to the class’s ::controller_name.



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

def controller_name
  self.class.controller_name
end

#dispatch(name, request, response) ⇒ Object

:nodoc:



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# File 'lib/action_controller/metal.rb', line 249

def dispatch(name, request, response) # :nodoc:
  set_request!(request)
  set_response!(response)
  process(name)
  request.commit_flash
  to_a
end

#headers ⇒ Object

Delegates to ActionDispatch::Response#headers.



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# File 'lib/action_controller/metal.rb', line 180

delegate :headers, to: "@_response"

#location ⇒ Object

Delegates to ActionDispatch::Response#location



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# File 'lib/action_controller/metal.rb', line 200

delegate :location, to: "@_response"

#location= ⇒ Object

Delegates to ActionDispatch::Response#location=



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

delegate :location=, to: "@_response"

#media_type ⇒ Object

Delegates to ActionDispatch::Response#media_type



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# File 'lib/action_controller/metal.rb', line 208

delegate :media_type, to: "@_response"

#params ⇒ Object 



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

def params
  @_params ||= request.parameters
end

#params=(val) ⇒ Object 



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# File 'lib/action_controller/metal.rb', line 223

def params=(val)
  @_params = val
end

#performed? ⇒ Boolean

Tests if render or redirect has already happened.

Returns:

  • (Boolean) 


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# File 'lib/action_controller/metal.rb', line 245

def performed?
  response_body || response.committed?
end

#request ⇒ Object

:attr_reader: request

The ActionDispatch::Request instance for the current request.



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

attr_internal :request

#reset_session ⇒ Object 



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# File 'lib/action_controller/metal.rb', line 284

def reset_session
  @_request.reset_session
end

#response ⇒ Object

:attr_reader: response

The ActionDispatch::Response instance for the current response.



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# File 'lib/action_controller/metal.rb', line 170

attr_internal_reader :response

#response=(response) ⇒ Object

Assign the response and mark it as committed. No further processing will occur.



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# File 'lib/action_controller/metal.rb', line 268

def response=(response)
  set_response!(response)

  # Force `performed?` to return true:
  @_response_body = true
end

#response_body=(body) ⇒ Object 



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# File 'lib/action_controller/metal.rb', line 234

def response_body=(body)
  if body
    body = [body] if body.is_a?(String)
    response.body = body
    super
  else
    response.reset_body!
  end
end

#session ⇒ Object

The ActionDispatch::Request::Session instance for the current request. See further details in the [Active Controller Session guide](guides.rubyonrails.org/action_controller_overview.html#session).



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# File 'lib/action_controller/metal.rb', line 176

delegate :session, to: "@_request"

#set_request!(request) ⇒ Object

:nodoc:



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# File 'lib/action_controller/metal.rb', line 275

def set_request!(request) # :nodoc:
  @_request = request
  @_request.controller_instance = self
end

#set_response!(response) ⇒ Object

:nodoc:



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# File 'lib/action_controller/metal.rb', line 257

def set_response!(response) # :nodoc:
  if @_response
    _, _, body = @_response
    body.close if body.respond_to?(:close)
  end

  @_response = response
end

#status ⇒ Object Also known as: response_code

Delegates to ActionDispatch::Response#status



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# File 'lib/action_controller/metal.rb', line 196

delegate :status, to: "@_response"

#status= ⇒ Object

Delegates to ActionDispatch::Response#status=



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# File 'lib/action_controller/metal.rb', line 184

delegate :status=, to: "@_response"

#to_a ⇒ Object

:nodoc:



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# File 'lib/action_controller/metal.rb', line 280

def to_a # :nodoc:
  response.to_a
end

#url_for(string) ⇒ Object

Basic ‘url_for` that can be overridden for more robust functionality.



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# File 'lib/action_controller/metal.rb', line 230

def url_for(string)
  string
end