class ActionController::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.
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.
Public Class Methods
# File actionpack/lib/action_controller/metal.rb, line 232 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
Returns a Rack endpoint for the given action name.
# File actionpack/lib/action_controller/metal.rb, line 129 def self.controller_name @controller_name ||= name.demodulize.sub(/Controller$/, "").underscore end
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
# File actionpack/lib/action_controller/metal.rb, line 248 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
Direct dispatch to the controller. Instantiates the controller, then executes the action named name
.
# File actionpack/lib/action_controller/metal.rb, line 133 def self.make_response!(request) ActionDispatch::Response.new.tap do |res| res.request = request end end
# File actionpack/lib/action_controller/metal.rb, line 227 def self.middleware middleware_stack end
Alias for middleware_stack
.
# File actionpack/lib/action_controller/metal.rb, line 153 def initialize @_request = nil @_response = nil @_routes = nil super end
# File actionpack/lib/action_controller/metal.rb, line 222 def self.use(*args, &block) middleware_stack.use(*args, &block) end
Pushes the given Rack middleware and its arguments to the bottom of the middleware stack.
Public Instance Methods
# File actionpack/lib/action_controller/metal.rb, line 144 def controller_name self.class.controller_name end
Delegates to the class' controller_name
.
# File actionpack/lib/action_controller/metal.rb, line 160 def params @_params ||= request.parameters end
# File actionpack/lib/action_controller/metal.rb, line 164 def params=(val) @_params = val end
# File actionpack/lib/action_controller/metal.rb, line 184 def performed? response_body || response.committed? end
Tests if render or redirect has already happened.
# File actionpack/lib/action_controller/metal.rb, line 209 def reset_session @_request.reset_session end
# File actionpack/lib/action_controller/metal.rb, line 175 def response_body=(body) body = [body] unless body.nil? || body.respond_to?(:each) response.reset_body! return unless body response.body = body super end
# File actionpack/lib/action_controller/metal.rb, line 171 def url_for(string) string end
Basic #url_for that can be overridden for more robust functionality.
© 2004–2019 David Heinemeier Hansson
Licensed under the MIT License.