Class: ActionController::Metal

Inherits:
AbstractController::Base show all
Defined in:
lib/action_controller/metal.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

Base, Middleware

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from AbstractController::Base

abstract!, #action_methods, action_methods, #available_action?, clear_action_methods!, controller_path, #controller_path, hidden_actions, internal_methods, method_added, #process, supports_path?

Constructor Details

#initialize ⇒ Metal

Returns a new instance of Metal.



131
132
133
134
135
136
137
138
 
# File '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 Method Details

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

Returns a Rack endpoint for the given action name.



231
232
233
234
235
236
237
238
239
 
# File '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) ⇒ Object

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



225
226
227
228
 
# File '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 ⇒ 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



113
114
115
 
# File 'lib/action_controller/metal.rb', line 113

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

.inherited(base) ⇒ Object

:nodoc:



207
208
209
210
 
# File 'lib/action_controller/metal.rb', line 207

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

.middleware ⇒ Object

Alias for middleware_stack.



219
220
221
 
# File 'lib/action_controller/metal.rb', line 219

def self.middleware
  middleware_stack
end

.use(*args, &block) ⇒ Object

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



214
215
216
 
# File 'lib/action_controller/metal.rb', line 214

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

Instance Method Details

#content_type ⇒ Object 



156
157
158
 
# File 'lib/action_controller/metal.rb', line 156

def content_type
  headers["Content-Type"]
end

#content_type=(type) ⇒ Object

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



152
153
154
 
# File 'lib/action_controller/metal.rb', line 152

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

#controller_name ⇒ Object

Delegates to the class’ controller_name



118
119
120
 
# File 'lib/action_controller/metal.rb', line 118

def controller_name
  self.class.controller_name
end

#dispatch(name, request) ⇒ Object

:nodoc:



192
193
194
195
196
197
198
 
# File 'lib/action_controller/metal.rb', line 192

def dispatch(name, request) #:nodoc:
  @_request = request
  @_env = request.env
  @_env['action_controller.instance'] = self
  process(name)
  to_a
end

#env ⇒ Object 



103
104
105
 
# File 'lib/action_controller/metal.rb', line 103

def env
  @_env ||= {}
end

#location ⇒ Object 



160
161
162
 
# File 'lib/action_controller/metal.rb', line 160

def location
  headers["Location"]
end

#location=(url) ⇒ Object 



164
165
166
 
# File 'lib/action_controller/metal.rb', line 164

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

#params ⇒ Object 



140
141
142
 
# File 'lib/action_controller/metal.rb', line 140

def params
  @_params ||= request.parameters
end

#params=(val) ⇒ Object 



144
145
146
 
# File 'lib/action_controller/metal.rb', line 144

def params=(val)
  @_params = val
end

#performed? ⇒ Boolean

Tests if render or redirect has already happened.

Returns:

  • (Boolean) 


188
189
190
 
# File 'lib/action_controller/metal.rb', line 188

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

#response_body=(body) ⇒ Object 



182
183
184
185
 
# File 'lib/action_controller/metal.rb', line 182

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

#status ⇒ Object Also known as: response_code 



173
174
175
 
# File 'lib/action_controller/metal.rb', line 173

def status
  @_status
end

#status=(status) ⇒ Object 



178
179
180
 
# File 'lib/action_controller/metal.rb', line 178

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

#to_a ⇒ Object

:nodoc:



200
201
202
 
# File 'lib/action_controller/metal.rb', line 200

def to_a #:nodoc:
  response ? response.to_a : [status, headers, response_body]
end

#url_for(string) ⇒ Object

Basic url_for that can be overridden for more robust functionality



169
170
171
 
# File 'lib/action_controller/metal.rb', line 169

def url_for(string)
  string
end