1 files changed, 80 insertions, 21 deletions

diff --git a/actionpack/lib/action_controller/metal.rb b/actionpack/lib/action_controller/metal.rb
index 2281c500c5..e5db31061b 100644
--- a/actionpack/lib/action_controller/metal.rb
+++ b/actionpack/lib/action_controller/metal.rb
@@ -12,7 +12,7 @@ module ActionController
   #
   class MiddlewareStack < ActionDispatch::MiddlewareStack #:nodoc:
     class Middleware < ActionDispatch::MiddlewareStack::Middleware #:nodoc:
-      def initialize(klass, *args)
+      def initialize(klass, *args, &block)
         options = args.extract_options!
         @only   = Array(options.delete(:only)).map(&:to_s)
         @except = Array(options.delete(:except)).map(&:to_s)
@@ -36,35 +36,88 @@ module ActionController
       action = action.to_s
       raise "MiddlewareStack#build requires an app" unless app
 
-      reverse.inject(app) do |a, middleware|
+      middlewares.reverse.inject(app) do |a, middleware|
         middleware.valid?(action) ?
           middleware.build(a) : a
       end
     end
   end
 
-  # ActionController::Metal provides a way to get a valid Rack application from a controller.
+  # <tt>ActionController::Metal</tt> is the simplest possible controller, providing a
+  # valid Rack interface without the additional niceties provided by
+  # <tt>ActionController::Base</tt>.
+  #
+  # 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 <tt>config/routes.rb</tt>:
+  #
+  #   match 'hello', :to => HelloController.action(:index)
+  #
+  # The +action+ method returns a valid Rack application for the \Rails
+  # router to dispatch to.
+  #
+  # == Rendering Helpers
+  #
+  # <tt>ActionController::Metal</tt> by default provides no utilities for rendering
+  # views, partials, or other responses aside from explicitly calling of
+  # <tt>response_body=</tt>, <tt>content_type=</tt>, and <tt>status=</tt>. To
+  # add the render helpers you're used to having in a normal controller, you
+  # can do the following:
+  #
+  #   class HelloController < ActionController::Metal
+  #     include ActionController::Rendering
+  #     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 <tt>ActionController::Base</tt> to see
+  # other features you can bring into your metal 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!
 
-    attr_internal :env
+    attr_internal_writer :env
+
+    def env
+      @_env ||= {}
+    end
 
     # 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
+    # <tt>Controller</tt>. For instance, PostsController returns <tt>posts</tt>.
+    # Namespaces are left out, so Admin::PostsController returns <tt>posts</tt> as well.
     #
     # ==== Returns
-    # String
+    # * <tt>string</tt>
     def self.controller_name
       @controller_name ||= self.name.demodulize.sub(/Controller$/, '').underscore
     end
 
-    # Delegates to the class' #controller_name
+    # Delegates to the class' <tt>controller_name</tt>
     def controller_name
       self.class.controller_name
     end
@@ -81,6 +134,9 @@ module ActionController
     def initialize(*)
       @_headers = {"Content-Type" => "text/html"}
       @_status = 200
+      @_request = nil
+      @_response = nil
+      @_routes = nil
       super
     end
 
@@ -112,6 +168,11 @@ module ActionController
       headers["Location"] = url
     end
 
+    # basic url_for that can be overridden for more robust functionality
+    def url_for(string)
+      string
+    end
+
     def status
       @_status
     end
@@ -121,12 +182,11 @@ module ActionController
     end
 
     def response_body=(val)
-      body = val.respond_to?(:each) ? val : [val]
+      body = val.nil? ? nil : (val.respond_to?(:each) ? val : [val])
       super body
     end
 
-    # :api: private
-    def dispatch(name, request)
+    def dispatch(name, request) #:nodoc:
       @_request = request
       @_env = request.env
       @_env['action_controller.instance'] = self
@@ -134,8 +194,7 @@ module ActionController
       to_a
     end
 
-    # :api: private
-    def to_a
+    def to_a #:nodoc:
       response ? response.to_a : [status, headers, response_body]
     end
 
@@ -147,8 +206,8 @@ module ActionController
       super
     end
 
-    def self.use(*args)
-      middleware_stack.use(*args)
+    def self.use(*args, &block)
+      middleware_stack.use(*args, &block)
     end
 
     def self.middleware
@@ -164,10 +223,10 @@ module ActionController
     # for the same action.
     #
     # ==== Parameters
-    # action<#to_s>:: An action name
+    # * <tt>action</tt> - An action name
     #
     # ==== Returns
-    # Proc:: A rack application
+    # * <tt>proc</tt> - A rack application
     def self.action(name, klass = ActionDispatch::Request)
       middleware_stack.build(name.to_s) do |env|
         new.dispatch(name, klass.new(env))