class Payment < ActiveRecord::Base
  def self.new_payment(payment_type, credit_card_type)
    case payment_type
      when 'paypal'
        PaypalPayment.new
     when 'promotional'
        PromotionalPayment.new
      when 'credit_card'
        CreditCardPayment.new_payment credit_card_type
    end
  end
end
