Mixpanel generic module as a mixin in AR using ActiveSupport

mixpanel.rb

# using active_support
require 'active_support/core_ext'

module Mixpanel
  extend ActiveSupport::Concern

  # class methods
  included do
    mixpanel
  end

  # instance methods
  def to_mixpanel
    res = self.mp_attrs.reduce({}) {|memo, attr|
      target = send(attr)
      memo[attr] = target.respond_to?(:item_value) ? target.item_value : target
      memo
    }
  end

  module ClassMethods
    def mixpanel(*names)
      cattr_accessor :mp_attrs
      self.mp_attrs = names
    end
  end
end

class Test < Object
  include Mixpanel

  attr_accessor :name, :desc

  mixpanel :name, :desc
end

t = Test.new
t.name = "Foo"
t.desc = "Description"

p t.to_mixpanel