A file to demonstrate the difference between extending with ActiveSupport::Concern and without

concerned.rb

require 'rubygems'
require 'active_support'

module Stuff

  # New hotness
  extend ActiveSupport::Concern

  def whatnot
    6
  end

  # Old and busted
  # def self.included(base)
  #   base.send :include, InstanceMethods
  #   base.send :extend, ClassMethods
  # end
  # 
  # module InstanceMethods
  #   def whatnot
  #     6
  #   end
  # end

  module ClassMethods
    def whatnot
      42
    end
  end
end

class Thing
  include Stuff
end

puts Thing.new.whatnot