Handle Declines and Retries

Retrying a definitively declined charge — the same card, the same amount, immediately again — accomplishes nothing except annoying the customer and potentially triggering fraud detection on the gateway's side. This is exactly why Lesson 1 defined declined as a distinct, non-retryable outcome from error in the first place.

public class ProcessPaymentJob implements Queueable {
    private Id orderId;
    private Decimal amount;
    private String paymentToken;
    private Integer attemptNumber;

    public ProcessPaymentJob(Id orderId, Decimal amount, String paymentToken, Integer attemptNumber) {
        this.orderId = orderId;
        this.amount = amount;
        this.paymentToken = paymentToken;
        this.attemptNumber = attemptNumber;
    }

    public void execute(QueueableContext context) {
        PaymentResult result = new PaymentGatewayService().charge(amount, paymentToken);

        Order__c order = new Order__c(Id = orderId);
        if (result.success) {
            order.Status__c = 'Paid';
            order.Payment_Reference__c = result.gatewayTransactionId;
            update order;
        } else if (result.declined) {
            order.Status__c = 'Payment Declined';
            order.Decline_Reason__c = result.message;
            update order;
        } else if (attemptNumber < 3) {
            System.enqueueJob(new ProcessPaymentJob(orderId, amount, paymentToken, attemptNumber + 1));
        } else {
            order.Status__c = 'Payment Error';
            update order;
        }
    }
}

attemptNumber (Module 9's parameter passing, extended with one more field) tracks how many times this specific charge has been attempted — an error triggers Module 38's job-chaining pattern to retry, but only up to 3 attempts, after which it gives up and records the final error status.

if (justReadyForPayment) {
    System.enqueueJob(new ProcessPaymentJob(order.Id, order.Total__c, order.Payment_Token__c, 1));
}

The trigger's original enqueue call now passes 1 as the starting attemptNumber — the first attempt — with ProcessPaymentJob itself handling every retry afterward via chaining, never requiring the original trigger to know or care about retries at all.