require 'active_support/core_ext/class/attribute' module ActionController # ActionController::Metal provides a way to get a valid Rack application from a controller. # # In AbstractController, dispatching is triggered directly by calling #process on a new controller. # ActionController::Metal provides an #action method that returns a valid Rack application for a # given action. Other rack builders, such as Rack::Builder, Rack::URLMap, and the Rails router, # can dispatch directly to the action returned by FooController.action(:index). class Metal < AbstractController::Base abstract! # :api: public attr_internal :params, :env # Returns the last part of the controller's name, underscored, without the ending # "Controller". For instance, MyApp::MyPostsController would return "my_posts" for # controller_name # # ==== Returns # String def self.controller_name @controller_name ||= controller_path.split("/").last end # Delegates to the class' #controller_name def controller_name self.class.controller_name end # The details below can be overridden to support a specific # Request and Response object. The default ActionController::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. attr_internal :status, :headers, :content_type, :response def initialize(*) @_headers = {} super end # Basic implementations for content_type=, location=, and headers are # provided to reduce the dependency on the RackDelegation module # in Renderer and Redirector. def content_type=(type) headers["Content-Type"] = type.to_s end def content_type headers["Content-Type"] end def location headers["Location"] end def location=(url) headers["Location"] = url end def status=(status) @_status = Rack::Utils.status_code(status) end # :api: private def dispatch(name, env) @_env = env @_env['action_controller.instance'] = self process(name) to_a end # :api: private def to_a response ? response.to_a : [status, headers, response_body] end class ActionEndpoint @@endpoints = Hash.new {|h,k| h[k] = Hash.new {|sh,sk| sh[sk] = {} } } def self.for(controller, action, stack) @@endpoints[controller][action][stack] ||= begin endpoint = new(controller, action) stack.build(endpoint) end end def initialize(controller, action) @controller, @action = controller, action @_formats = [Mime::HTML] end def call(env) @controller.new.dispatch(@action, env) end end class_attribute :middleware_stack self.middleware_stack = ActionDispatch::MiddlewareStack.new def self.inherited(base) self.middleware_stack = base.middleware_stack.dup end def self.use(*args) middleware_stack.use(*args) end def self.middleware middleware_stack end def self.call(env) action(env['action_dispatch.request.path_parameters'][:action]).call(env) end # Return a rack endpoint for the given action. Memoize the endpoint, so # multiple calls into MyController.action will return the same object # for the same action. # # ==== Parameters # action<#to_s>:: An action name # # ==== Returns # Proc:: A rack application def self.action(name) ActionEndpoint.for(self, name, middleware_stack) end end end