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.
- A
- C
- D
- M
- N
- P
- R
- U
Returns a Rack endpoint for the given action name.
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
Direct dispatch to the controller. Instantiates the controller, then
executes the action named name
.
Alias for middleware_stack
.
Pushes the given Rack middleware and its arguments to the bottom of the middleware stack.
Delegates to the class' controller_name
.
Tests if render or redirect has already happened.
# 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 # Tests if render or redirect has already happened. def performed? response_body || response.committed? end def dispatch(name, request, response) #:nodoc: set_request!(request) set_response!(response) process(name) request.commit_flash to_a end def set_response!(response) # :nodoc: @_response = response end def set_request!(request) #:nodoc: @_request = request @_request.controller_instance = self end def to_a #:nodoc: response.to_a end def reset_session @_request.reset_session end class_attribute :middleware_stack, default: ActionController::MiddlewareStack.new def self.inherited(base) # :nodoc: base.middleware_stack = middleware_stack.dup super end # Pushes the given Rack middleware and its arguments to the bottom of the # middleware stack. def self.use(*args, &block) middleware_stack.use(*args, &block) end # Alias for +middleware_stack+. def self.middleware middleware_stack end # Returns a Rack endpoint for the given action name. 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 # Direct dispatch to the controller. Instantiates the controller, then # executes the action named +name+. 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 end