This package is endorsed, which means you can simply use shared_preferences and in_app_purchase normally. This package will be automatically included in your app when you do, so you do not need to add it to your pubspec.yaml.

Features

OnePref offers the same functionality shared_preferences package offers but in a friendly way and it has other in app purchase functions to fast track your development when you add in app purchase in your application.

Getting started

flutter pub add onepref

import 'package:onepref/onepref.dart' 

//In your main.dart
void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await OnePref.init();
  runApp(const MyApp());
}

Usage

To Write

OnePref.setString("key","value here");

Get the Value

const value = OnePref.getString("key");

To get Products

//declare these 

late final List<String> _notFoundIds = <String>[];
late final List<ProductDetails> _products = <ProductDetails>[];
late final List<PurchaseDetails> _purchases = <PurchaseDetails>[];
late bool _isAvailable = false;
late bool _purchasePending = false;

IApEngine iApEngine = IApEngine();

ATTENTATION !!!!!  ATTENTATION !!!!!   ATTENTATION !!!!!
//(Please make sure you have configured in App purchase for your app)

@override
void initState() {
  super.initState();
  
  iApEngine.inAppPurchase.purchaseStream.listen(
          (List<PurchaseDetails> purchaseDetailsList) {
        //listen to the purchases
        listenToPurchaseUpdated(purchaseDetailsList);
      }, onDone: () {}, onError: (Object error) {});
  
  getProducts();// calling get products
}

void getProducts() async {
    // Querying the products from Google Play
    await iApEngine.getIsAvailable().then((isAvailable) async {
      if (isAvailable) {
        await iApEngine
            .queryProducts(Constants.storeProductIds)
            .then((value) => {
                  setState(() {
                    _isAvailable = isAvailable;
                    _products.addAll(value
                        .productDetails); // Setting the returned products here.
                    _notFoundIds.addAll(value
                        .notFoundIDs); // Setting the returned notProductIds here.
                    _purchasePending = false;
                  })
                });
      }
    });
  }

HandlePurchase

 TextButton(onPressed: () {
     iApEngine.handlePurchase(_products[selectedProduct ?? 0],Constants.storeProductIds);},
   child: Text("Buy $reward",
                textAlign: TextAlign.center,
            style: const TextStyle(
           color: Colors.white, fontSize: 14,
          fontWeight: FontWeight.normal,
       ),
     ),
  ),

Libraries

onepref