Commerce Reference Store supports two payment options: gift certificates and a single credit card. (Commerce Reference Store does not support using multiple credit cards to pay for an individual order.) To use a gift certificate, the customer enters the claim code that was sent by email. Multiple gift certificates can be used by entering their claim codes, separated by spaces. If the value of the gift certificates used is less than the order total, the entire value of the gift certificates is applied, and the remainder is charged to the credit card.
If the total value of a gift certificate is not used (e.g., if a customer makes a $30 purchase with a $50 gift certificate), the amount remaining is stored for future use. The customer can use this amount for a future order by entering the same claim code.
A customer who is not logged in can check out using gift certificates or a credit card entered during checkout for payment. A customer who is logged in also has the option of choosing a saved credit card.
The billing page, /checkout/billing.jsp, includes the /checkout/gadget/billingForm.jsp gadget, which contains the form used for specifying payment options. This gadget uses the /atg/store/order/purchase/BillingFormHandler to create the form and apply the payment options the customer specifies. The BillingFormHandler is of class atg.projects.store.order.purchase.BillingInfoFormHandler, which extends the atg.commerce.order.purchase.PurchaseProcessFormHandler abstract class.
