lib/generators/templates/models/payment.rb
class <%= Paysto.payment_class_name %> < ActiveRecord::Base
# attr_accessible :amount,
# :real_amount,
# :gateway_code,
# :gateway_payment_method
has_one :<%= Paysto.invoice_class_name.underscore %>, class_name: '<%= Paysto.invoice_class_name %>', dependent: :destroy
validates :amount, presence: true
validates :amount, exclusion: { in: [0] }, allow_nil: false
end