In addition to Credit Card component extensions, the Payment Manager supports instances of client payment components (CPCs) that offer other payment types other than credit cards (such as electronic cash). The following interfaces support a CPC and the installation of a CPC:
Use the functions in the client payment component (CPC) interfaces to offer additional payment types in the Microsoft Payment Selector. The Payment Manager calls methods on the IClientPaymentProvider interface to create and manage instances of a payment type in your CPC. The IWalletCallback interface methods guarantee that instances of payment types have unique names across all components in the Payment Selector. You can use these interfaces to present instances of your payment type (or types) as an option for Payment Selector users during online purchasing transactions. You must implement all the methods in the IClientPaymentProvider interface in order for the Payment Selector to fully support your CPC. In addition, call functions on the IPaymentProviderInstall interface in order to support the installation package for your CPC.
Note As a COM object, a CPC is responsible for its own memory allocation. When the reference count is zero, the CPC frees memory allocated to that object. All calls may return the E_OUTOFMEMORY (memory allocation failure) value.
A CPC object in the Payment Selector represents a payment method such as credit cards or electronic cash debit cards. Each CPC supports one or more types of that method. For example, a type of a credit card payment method is a VISA card. Each CPC may contain zero or more instances of any type supported by that CPC. Each instance possesses a friendly name that is unique across all CPC modules in the Payment Selector.
The Payment Selector provides the consumer with a rich user interface for managing and selecting instances of payment types. Payment types (such as a VISA, bank, or department store card) are stored in the Payment Selector. When a user creates a new instance of an existing payment type (such as a second bank card), that instance is stored by the payment type component. These instances are locally managed according to a friendly name that is assigned by the user. Note that instances of payment types are never shared between different components in the Payment Selector.
After a consumer selects an instance of a payment type from the Payment Selector, a payment instruction (PI) is generated in that payment type component, routed through the Payment Selector, and sent over the browser to the server for the merchant to process payment. The PI may be encrypted and will pass through the Payment Selector as opaque data.
All individual elements stored inside a CPC are retrieved by an index position. The accessor is treated as a zero-based array. There is no order imposed on the array and elements may move in the array during the lifetime of the object. For example, a delete operation will not leave a hole in the array. The index positions will change only during add or delete operations.