Attach Callbacks to Methods In a Module

module_callbacks.rb

#http://stackoverflow.com/questions/5513558/executing-code-for-every-method-call-in-a-ruby-module

module M
  def self.before(*names)
    names.each do |name|
      m = instance_method(name)
      define_method(name) do |*args, &block|  
        yield
        m.bind(self).(*args, &block)
      end
    end
  end
end

module M
  def hello
    puts "yo"
  end

  def bye
    puts "bum"
  end

  before(*instance_methods) { puts "start" }
end

class C
  include M
end

C.new.bye #=> "start" "bum"
C.new.hello #=> "start" "yo"