How to use in_app_purchase using BLoC? - flutter

Question

I'm trying to refactor my code a little bit, and I want to refactor payment logic using BLoC.
The problem is that I'm still getting an error that says:
emit was called after an event handler completed normally.
I only need information from state if the transaction is Pending, Complete or there is an error, so there is only true or false to show the CircularIndicator.
There is my try to implement Payment using BLoC.
_onStarted - starts subscription and is called once on initState
_buyProduct - is called when user hits the button
class PaymentBloc extends Bloc<PaymentEvent, PaymentState> {
static const bool _started = false;
final InAppPurchase _inAppPurchase = InAppPurchase.instance;
Set<String> _kProductIds = {"mini_burger_4_99"};
List<ProductDetails> _products = [];
PaymentBloc() : super(PaymentInitial(_started)) {
on<PaymentStarted>(_onStarted);
on<PaymentCompletion>(_buyProduct);
}
StreamSubscription<List<PurchaseDetails>>? _subscription;
void _onStarted(PaymentStarted event, Emitter<PaymentState> emit) {
final Stream<List<PurchaseDetails>> purchaseUpdated =
_inAppPurchase.purchaseStream;
_subscription = purchaseUpdated.listen((purchaseDetailsList) {
purchaseDetailsList.forEach((PurchaseDetails purchaseDetails) async {
if (purchaseDetails.status == PurchaseStatus.pending) {
emit(PaymentPending());
} else {
if (purchaseDetails.status == PurchaseStatus.error) {
emit(PaymentError());
} else if (purchaseDetails.pendingCompletePurchase) {
await _inAppPurchase.completePurchase(purchaseDetails);
emit(PaymentComplete());
}
}
});
}, onDone: () {
_subscription?.cancel();
}, onError: (error) {
// handle error.
});
initStoreInfo();
}
Future<void> _buyProduct(
PaymentCompletion event, Emitter<PaymentState> emit) async {
var paymentWrapper = SKPaymentQueueWrapper();
var transactions = await paymentWrapper.transactions();
transactions.forEach((transaction) async {
await paymentWrapper.finishTransaction(transaction);
});
final PurchaseParam purchaseParam = PurchaseParam(
productDetails:
_products.firstWhere((product) => product.id == event.id));
await _inAppPurchase.buyConsumable(purchaseParam: purchaseParam);
}
#override
Future<void> close() {
_subscription?.cancel();
return super.close();
}
Future<void> initStoreInfo() async {
final bool isAvailable = await _inAppPurchase.isAvailable();
if (!isAvailable) {
_products = [];
return;
}
if (Platform.isIOS) {
var iosPlatformAddition = _inAppPurchase
.getPlatformAddition<InAppPurchaseIosPlatformAddition>();
await iosPlatformAddition.setDelegate(ExamplePaymentQueueDelegate());
}
ProductDetailsResponse productDetailResponse =
await _inAppPurchase.queryProductDetails(_kProductIds);
if (productDetailResponse.error != null) {
_products = productDetailResponse.productDetails;
return;
}
if (productDetailResponse.productDetails.isEmpty) {
_products = productDetailResponse.productDetails;
return;
}
_products = productDetailResponse.productDetails;
}
}
Thanks for any kind of help.
Matt