Request

In order to access the metadata coming from a HTTP request, an action has a private object request that derives from Rack::Request. Here an example of some information that we can introspect.

# apps/web/controllers/dashboard/index.rb
module Web
  module Controllers
    module Dashboard
      class Index
        include Web::Action
        def call(params)
          puts request.path_info                 # => "/dashboard"
          puts request.request_method            # => "GET"
          puts request.get?                      # => true
          puts request.post?                     # => false
          puts request.xhr?                      # => false
          puts request.referer                   # => "http://example.com/"
          puts request.user_agent                # => "Mozilla/5.0 Macintosh; ..."
          puts request.ip                        # => "127.0.0.1"
          puts request.env['HTTP_AUTHORIZATION'] # => "Basic abc123"
        end
      end
    end
  end
end

Instantiating a request for each incoming HTTP request can lead to minor performance degradation. As an alternative, please consider getting the same information from private action methods like accept? or from the raw Rack environment params.env.

Response

The implicit return value of #call is a serialized Rack::Response (see #finish):

# apps/web/controllers/dashboard/index.rb
module Web
  module Controllers
    module Dashboard
      class Index
        include Web::Action
        def call(params)
        end
      end
    end
  end
end
# It will return [200, {}, [""]]

It has private accessors to explicitly set status, headers and body:

# apps/web/controllers/dashboard/index.rb
module Web
  module Controllers
    module Dashboard
      class Index
        include Web::Action
        def call(params)
          self.status = 201
          self.body   = 'Your resource has been created'
          self.headers.merge!({ 'X-Custom' => 'OK' })
        end
      end
    end
  end
end
# It will return [201, { "X-Custom" => "OK" }, ["Your resource has been created"]]

As shortcut we can use #status.

# apps/web/controllers/dashboard/index.rb
module Web
  module Controllers
    module Dashboard
      class Index
        include Web::Action
        def call(params)
          status 201, "Your resource has been created"
        end
      end
    end
  end
end
# It will return [201, {}, ["Your resource has been created"]]