Class: ActionController::Metal

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

Overview

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

ActionController::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 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?

Methods included from ActiveSupport::DescendantsTracker

clear, #descendants, descendants, #direct_descendants, direct_descendants, disable_clear!, #inherited, native?, store_inherited, subclasses, #subclasses

Methods included from ActiveSupport::Configurable

#config

Methods included from ActiveSupport::Concern

#append_features, #class_methods, extended, #included, #prepend_features, #prepended

Constructor Details

#initializeMetal

Returns a new instance of Metal.


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# File 'actionpack/lib/action_controller/metal.rb', line 150

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

Class Method Details

.action(name) ⇒ Object

Returns a Rack endpoint for the given action name.


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

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 'actionpack/lib/action_controller/metal.rb', line 136

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

.controller_nameObject

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 'actionpack/lib/action_controller/metal.rb', line 126

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 'actionpack/lib/action_controller/metal.rb', line 247

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

.inherited(base) ⇒ Object

:nodoc:


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# File 'actionpack/lib/action_controller/metal.rb', line 212

def self.inherited(base) # :nodoc:
  base.middleware_stack = middleware_stack.dup
  super
end

.make_response!(request) ⇒ Object


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

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

.middlewareObject

Alias for middleware_stack.


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# File 'actionpack/lib/action_controller/metal.rb', line 226

def self.middleware
  middleware_stack
end

.useObject

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


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# File 'actionpack/lib/action_controller/metal.rb', line 220

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

Instance Method Details

#controller_nameObject

Delegates to the class's ::controller_name.


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# File 'actionpack/lib/action_controller/metal.rb', line 141

def controller_name
  self.class.controller_name
end

#dispatch(name, request, response) ⇒ Object

:nodoc:


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# File 'actionpack/lib/action_controller/metal.rb', line 185

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

#paramsObject


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# File 'actionpack/lib/action_controller/metal.rb', line 157

def params
  @_params ||= request.parameters
end

#params=(val) ⇒ Object


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# File 'actionpack/lib/action_controller/metal.rb', line 161

def params=(val)
  @_params = val
end

#performed?Boolean

Tests if render or redirect has already happened.

Returns:

  • (Boolean)

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# File 'actionpack/lib/action_controller/metal.rb', line 181

def performed?
  response_body || response.committed?
end

#reset_sessionObject


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# File 'actionpack/lib/action_controller/metal.rb', line 206

def reset_session
  @_request.reset_session
end

#response_body=(body) ⇒ Object


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# File 'actionpack/lib/action_controller/metal.rb', line 172

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

#set_request!(request) ⇒ Object

:nodoc:


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# File 'actionpack/lib/action_controller/metal.rb', line 197

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

#set_response!(response) ⇒ Object

:nodoc:


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# File 'actionpack/lib/action_controller/metal.rb', line 193

def set_response!(response) # :nodoc:
  @_response = response
end

#to_aObject

:nodoc:


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# File 'actionpack/lib/action_controller/metal.rb', line 202

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 'actionpack/lib/action_controller/metal.rb', line 168

def url_for(string)
  string
end