πŸ› οΈ OnePref + InAppEngine

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 β€” no need to add it manually to your pubspec.yaml.

✨ Features

OnePref provides the same functionality as shared_preferences, but in a simpler, developer-friendly API.
Additionally, it includes an InAppEngine utility that helps you integrate in-app purchases quickly and safely β€” saving you hours of setup time.

Key Highlights

  • πŸš€ Simplified preference storage using OnePref.
  • πŸ’° Streamlined in-app purchase management for Android & iOS.
  • 🧾 Support for both consumable and non-consumable products.
  • πŸ” Built-in subscription upgrade/downgrade support (Android).
  • 🧩 Easy product query and restore logic.
  • 🧠 Debug-friendly logs and structured PurchaseResult.

πŸš€ Getting Started

1️⃣ Install

flutter pub add onepref

import 'package:onepref/onepref.dart' 

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

Write a value

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

Read a value

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

πŸ›’ Usage (In-App Purchases)

⚠️ ATTENTION!

Before using InAppEngine, make sure you have correctly configured in-app purchases
in the Play Console (Android) or App Store Connect (iOS).

Setup variables

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;

final InAppEngine inAppEngine = InAppEngine.instance;

Initialize and Query Products


@override
void initState() {
  super.initState();

  // Listen to purchase updates
  inAppEngine.inAppPurchase.purchaseStream.listen(
    (List<PurchaseDetails> purchaseDetailsList) {
      listenToPurchaseUpdated(purchaseDetailsList);
    },
    onDone: () {},
    onError: (Object error) {
      debugPrint("Purchase Stream Error: $error");
    },
  );

  getProducts(); // Fetch product details
}

Future<void> getProducts() async {
  final isAvailable = await inAppEngine.getIsAvailable();

  if (isAvailable) {
    final response = await inAppEngine.queryProducts(Constants.storeProductIds);

    setState(() {
      _isAvailable = isAvailable;
      _products.addAll(response.productDetails);
      _notFoundIds.addAll(response.notFoundIDs);
      _purchasePending = false;
    });
  } else {
    debugPrint("Store not available.");
  }
}

Handle a Purchase

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

🧩 Bonus: Restoring Purchases

ElevatedButton(
  onPressed: () async {
    await inAppEngine.restorePurchases();
  },
  child: const Text("Restore Purchases"),
),
Feature Description
πŸ”Ή Shared Preferences Simple key/value storage with OnePref
πŸ”Ή Product Query Fetch Play/App Store products easily
πŸ”Ή Purchase Handling Buy consumables & non-consumables
πŸ”Ή Subscription Manage upgrades/downgrades on Android
πŸ”Ή Restore Restore past purchases with one line
πŸ”Ή Debug Logging Built-in safe logging for dev mode

πŸ“¦ Example Integration Flow

final engine = InAppEngine.instance;

await engine.initPurchaseStream(Constants.storeProductIds);

final available = await engine.getIsAvailable();
if (!available) return;

final products = await engine.queryProducts(Constants.storeProductIds);
if (products.productDetails.isNotEmpty) {
  await engine.handlePurchase(products.productDetails.first, Constants.storeProductIds);
}

Libraries

onepref