module Responders::ControllerMethod

responders :flash, MyCustomResponder

Or a mix of both methods:

responders FlashResponder, HttpCacheResponder

Also allows passing in the responders modules in directly, so you could do:
Takes symbols and strings and translates them to VariableResponder (eg. :flash becomes FlashResponder).

end
responders :flash, :http_cache
class InvitationsController < ApplicationController

which responders you want per controller.
Adds the given responders to the current controller's responder, allowing you to cherry-pick

def responders(*responders)
  self.responder = responders.inject(Class.new(responder)) do |klass, responder|
    responder = \
      case responder
      when Module
        responder
      when String, Symbol
        Responders.const_get("#{responder.to_s.camelize}Responder")
      else
        raise "responder has to be a string, a symbol or a module"
      end
    klass.send(:include, responder)
    klass
  end
end