Implement Payment Method with Payment Flow Footer

You may implement a new Payment Method with Flow and Payment Flow Footer:

1. Create an Apex class implements IPaymentHandler interface

2. Add the following 2 methods in the new Apex class

InitializePaymentResult initialize (PaymentContext context);
HandlePaymentResult handle(Payment payment, PaymentContext context);

3. Provide the following property values in method initialize:

• action.type
• action.actionTypeName
• action.componentName(= name of flow)
• payment.totalAmount

Sample of method initialize:

global virtual InitializePaymentResult initialize (PaymentContext context) {
InitializePaymentResult result = new InitializePaymentResult();
result.payment = new Payment();
result.payment.totalAmount = context.totalAmount;
result.action = new PaymentAction();
result.action.type = PaymentAction.ActionType.ScreenFlow;
result.action.actionTypeName = String.valueOf(result.action.type);
result.action.componentName = 'default_payment_flow';
return result;
}

4. The method handle should return the result of payment or the error message.
   Sample of method handle:

global virtual HandlePaymentResult handle(Payment payment, PaymentContext context) {
HandlePaymentResuLt result = new HandlePaymentResult();
result.success = validatePayment (payment, context);
// provide value for error
// result.success = false;
// result.message = 'test error';
return result;
}

private Boolean validatePayment (Payment payment, PaymentContext context) {
return true;
}

5. Create new Payment Method:
   Setup -> Custom Metadata Types -> Payment Method -> Manage Payment method -> New

6. Add the new Apex class name to Handler and save

7. Create a new Flow:
   Setup -> Flows -> New Flow

8. Set input and output variables.

9. Add a Screen component in the flow, drag and drop custom component Custom Flow Footer to the bottom of the Screen component, the API Name is PaymentFlowFooter.

10. Remove the tick from Show Footer in Configure Footer, then save the flow with the new Apex class name (same as what you filled in Handler of new Payment Method), and activate the flow.