paymentItems is not reactive

[dickermoshe]

BUG

If you change the value of paymentItems on a PayButton it doesn't update it internally.

Example

This Widget returns a ApplePayButton that will charge priceInCents.
However, If the parent widget changes the price (E.G. The customer selects a different tip amount) the payment will still show the original amount.

class PaymentButton extends HookConsumerWidget {
  const PaymentButton(
      {super.key,
      required this.priceInCents,
      this.onPressed,
      this.onSuccess,
      this.onError});
  final int priceInCents;
  final VoidCallback? onPressed;
  final VoidCallback? onSuccess;
  final void Function(Object?)? onError;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final paymentItems = [
      p.PaymentItem(
          label: "Donation",
          amount: (priceInCents / 100).toStringAsFixed(2),
          type: p.PaymentItemType.total,
          status: p.PaymentItemStatus.final_price)
    ];

    return p.ApplePayButton(
      onPressed: onPressed,
      paymentConfiguration:
          p.PaymentConfiguration.fromJsonString(defaultApplePay),
      type: p.ApplePayButtonType.donate,
      onPaymentResult: (result) {
        runApplePay(result, amountInCents: priceInCents);
        if (onSuccess != null) onSuccess!();
      },
      paymentItems: paymentItems,
    );
  }
}

Simulator.Screen.Recording.-.iPhone.15.Pro.-.2023-12-26.at.01.47.53.1.mp4

Temp Workaround

Assign the button a UniqueKey and change it when the priceInCents changes.
This will force Flutter to rebuild the entire ApplePayButton
(This is using flutter_hooks, but you could use something else to do this.)

 final buttonKey = useMemoized(() => UniqueKey(), [priceInCents]);

[dickermoshe]

Cause

This is because onMethodCallHandler is only called once.

flutter-plugin/pay_ios/lib/src/widgets/apple_pay_button.dart

Lines 153 to 162 in af2e70d

	return UiKitView(
	viewType: buttonId,
	creationParamsCodec: const StandardMessageCodec(),
	creationParams: {'style': style.enumString, 'type': type.enumString},
	onPlatformViewCreated: (viewId) {
	methodChannel = MethodChannel('$buttonId/$viewId');
	methodChannel?.setMethodCallHandler((call) async {
	if (call.method == 'onPressed') onPressed?.call();
	return;
	});

If we made _UiKitApplePayButton stateful, we could save the viewId to state and update the function if it changes.

[dickermoshe]

PR #236 fixes this.
Please upvote

[JlUgia]

Published under pay_ios:1.0.11 and pay:1.2.0-beta02.