Callback like Callbacks

gistfile1.rb

module Actions
  module Base
      def email(args)
	extend(Mail)
	send(*args)
      end
      def statistics(m,*args)
	extend(Statistics)
	send(m,*args)
      end
   end
   module Mail
      def complete#(args)
	puts "complete mail"
      end

      def auto_posted
	puts "posted"
      end
    end
    module Statistics
      def complete(args)
	puts "complete stats"
      end

      def posted(args)
	puts "posted #{args}"
      end
    end
end


module Events
   attr_accessor :wrapper

   def self.extended(base)
	base.wrapper = {}
	base.send(:include,Triggers)
   end

   def method_missing(meth,*args,&block)
	if @current_caller == :notification_callbacks
	  wrapper[meth] = block
	else
	  super
	end
   end

   def respond_to_missing?(m,include_private=false)
     wrapper.keys.include?(m)
   end
end

module Triggers
   def method_missing(m,*args,&block)
	current_wrapper = self.class.wrapper[m[0...-1].to_sym] #auto_posted
	if m.to_s.end_with?("!") && current_wrapper.present? #auto_posted!
		send(:extend, Actions::Base)
		current_wrapper.call(self)
	else
		super
	end
    end

    def respond_to_missing?(m,include_private=false)
        current_wrapper = self.class.wrapper[m[0...-1].to_sym] #auto_posted
	m.to_s.end_with?("!") && current_wrapper.present?
    end
end

module CallbackChain
   def notification_callbacks(&block)
	send(:extend, Events)
	@current_caller = __method__
	instance_eval(&block)
	@current_caller = nil
   end
end

class A
  extend CallbackChain

  notification_callbacks do
     completed_trip do |d|
	d.email :complete
	d.statistics :complete, 2
     end
     auto_posted do |d|
	d.email :auto_posted
	d.statistics :posted, 1
     end
   end
 end


A.new.completed_trip!