Use conditional calls and callbacks for implementation-specific functions. For example, to provide additional data from the cash register during a transaction, like loyalty data, you use the Additional Data Callback. If the cash register does not handle these calls and callbacks, they will block further processing of the transaction.
Optional calls and callbacks do not need confirmation from the POS system. For example, the progress callback does not require any action.
These optional extras allow you to integrate specific features from the library:
- Use CreateSpecialTender to start Alipay and WeChat pay transactions
- Handle the Dynamic Currency Conversion (DCC) callback
- Handle the Exception Callback
- Handle the LibraryLog callback
- Query the PED object for device information
- Retrieve transaction information from the TxStoreReport Object
- Use ShowScreen to display a screen on a large screen terminal (MX925)
- Start gift card transactions with CreateSpecialTender