Money represented with the Money gem, persistence using Mongoid 3

money_field.rb

class MoneyField

  def mongoize
      return if object.nil?
    cents
  end

  class << self
    def demongoize(object)
      return nil unless object
      Money.new(object)
    end
    def mongoize(object)
         Money.parse(object).cents
      end
    def evolve(object)
       Money.parse(object).cents
    end
  end

end