Event Class Mockup. Events are meant to be self-contained actions who only send and receive plain old ruby objects. An event can be used anywhere.

event_mockup.rb

class SomeController < ApplicationController

  def update
    handle_response SomeEvent::Update.new(params).invoke
  end

private

  ##
  # Performs some default action on the response. Probably just returns the
  # status code and/or displays a message/error based on the actions performed
  # in the Event.
  def handle_response(response)
    # boring stuff here.
  end

end

##
# An event is meant to be single action that is unaware of how it was invoked 
# or how it's response should be processed. The only data passed between borders 
# should be plain old ruby objects.
class SomeEvent::Update

  def initialize(params)
    @params = params
  end

  def invoke
    # perform the event (awesome event code goes here)
    awesome_event_logic

    message = 'some-event.success' # cause we're using l18n ;)
    data = {:awesome => true}

    # send back a response
    Event::Response.new :status => :success, :message => message, :data => whatever
  end

end

##
# An Event::Response object is the only thing that should ever be returned
# from Event#invoke. It should be generic in nature (and not contain things like 
# URLs or HTTP-specific resources). The controller then handles the response to 
# determine what actions should be taken based on the outcome of the event.
class Event::Response

  attr_reader :status, :message, :data

  def initialize(options={})
    @status = options[:status] if options[:status]
    @message = options[:message] if options[:message]
    @data = options[:data] if options[:data]
  end

end