gistfile1.txt

class Order < AR:Base
  
  has_one :credit_card_payment
  has_one :paypal_express_payment
  has_one :horse_shoe_payment

  validates_presence_of :payment_type, :in => [:credit_card_express, :paypal_express, :horse_shoe]


  def payment_proxy
    self.send("#{:payment_type.to_s}_payment")
  end

  # This one is for forms, like nested_attributes_for
  def payment_proxy_attributes=(payment_attributes)
    self.send("build_#{:payment_type.to_s}", payment_attributes)
  end
end