Migration from v5.x to v7.0+

This guide helps you migrate from flutter_inapp_purchase v5.x to the latest v7.0+ version.

Overview

Version 7.0+ is a major update with significant breaking changes to align with the OpenIAP specification and support modern platform APIs.

Migration Path

If you're migrating from v5.x, we recommend:

1. First migrate to v6.8 following this guide
2. Then migrate from v6.8 to v7.0 using the v6 to v7 migration guide

Installation

Update your pubspec.yaml:

dependencies:
  flutter_inapp_purchase: ^7.0.0

Key Changes Summary

• ✅ OpenIAP Compliance - Full alignment with OpenIAP specification
• ✅ StoreKit 2 Support for iOS 15.0+
• ✅ Billing Client v8 for Android
• ✅ Improved Type Safety with refined APIs
• ✅ Better Error Handling with standardized error codes
• ⚠️ Breaking Changes in error codes, method signatures, and data models

Major Breaking Changes

1. Error Code Format (CRITICAL)

The most significant breaking change is the error code enum format.

v5.x (Old):

// SCREAMING_SNAKE_CASE with E_ prefix
ErrorCode.E_USER_CANCELLED
ErrorCode.E_NETWORK_ERROR
ErrorCode.E_ITEM_UNAVAILABLE
ErrorCode.E_ALREADY_OWNED
ErrorCode.E_DEVELOPER_ERROR

v6.8+ (New):

// PascalCase format (OpenIAP standard)
ErrorCode.UserCancelled
ErrorCode.NetworkError
ErrorCode.ItemUnavailable
ErrorCode.AlreadyOwned
ErrorCode.DeveloperError

Migration:

// Before
if (error.code == ErrorCode.E_USER_CANCELLED) { ... }

// After
if (error.code == ErrorCode.UserCancelled) { ... }

2. Data Models

v5.x:

• IAPItem for products
• String-based product IDs
• Nullable fields everywhere

v6.8+:

• Product / ProductCommon for products
• Strongly typed with required fields
• Better null safety

// Before (v5.x)
class IAPItem {
  String? productId;
  String? price;
  String? currency;
  String? localizedPrice;
}

// After (v6.8+)
class Product {
  String id;              // Required
  double? price;          // Numeric
  String currency;        // Required
  String displayPrice;    // Required (localized)
  ProductType type;       // Required
}

3. fetchProducts API

v5.x:

// Old approach
List<IAPItem> items = await FlutterInappPurchase.instance
    .fetchProducts(skus: _productIds, type: 'inapp');

v6.8+:

// New OpenIAP-compliant approach
final result = await FlutterInappPurchase.instance.fetchProducts(
  ProductRequest(
    skus: _productIds,
    type: ProductQueryType.InApp,
  ),
);
final products = result.value;

4. requestPurchase API

v5.x:

// Simple string-based request
String msg = await FlutterInappPurchase.instance
    .requestPurchase(item.productId);

v6.8+:

// Structured request with platform-specific options
final requestProps = RequestPurchaseProps.inApp(
  request: RequestPurchasePropsByPlatforms(
    apple: RequestPurchaseIosProps(
      sku: productId,
      quantity: 1,
    ),
    google: RequestPurchaseAndroidProps(
      skus: [productId],
    ),
  ),
);

await FlutterInappPurchase.instance.requestPurchase(requestProps);

5. finishTransaction API

v5.x:

// iOS only, simple call
await FlutterInappPurchase.instance.finishTransaction(item);

v6.8+:

// Cross-platform with explicit consumable flag
await FlutterInappPurchase.instance.finishTransaction(
  purchase: item,
  isConsumable: true, // Required parameter
);

6. Stream Access

v5.x:

// Direct static stream access
FlutterInappPurchase.iapUpdated.listen(...);

v6.8+:

// Instance-based stream access
FlutterInappPurchase.instance.purchaseUpdated.listen(...);
FlutterInappPurchase.instance.purchaseError.listen(...);

7. Android Methods

v5.x:

await FlutterInappPurchase.instance.consumePurchase(
  purchaseToken: token,
);
await FlutterInappPurchase.instance.acknowledgePurchase(
  purchaseToken: token,
);

v6.8+:

// Explicit Android suffix for clarity
await FlutterInappPurchase.instance.consumePurchaseAndroid(
  purchaseToken: token,
);
await FlutterInappPurchase.instance.acknowledgePurchaseAndroid(
  purchaseToken: token,
);

Step-by-Step Migration

Step 1: Update Dependencies

Update your pubspec.yaml:

dependencies:
  flutter_inapp_purchase: ^6.8.0

Run:

flutter pub get

Step 2: Update Error Code Handling

Find and replace all error code references:

Search for:

ErrorCode.E_USER_CANCELLED
ErrorCode.E_NETWORK_ERROR
ErrorCode.E_ITEM_UNAVAILABLE
ErrorCode.E_ALREADY_OWNED

Replace with:

ErrorCode.UserCancelled
ErrorCode.NetworkError
ErrorCode.ItemUnavailable
ErrorCode.AlreadyOwned

Step 3: Update Stream Listeners

Before:

_purchaseUpdatedSubscription = FlutterInappPurchase.iapUpdated.listen((data) {
  print('purchase-updated: $data');
});

_purchaseErrorSubscription = FlutterInappPurchase.iapUpdated.listen((data) {
  print('purchase-error: $data');
});

After:

_purchaseUpdatedSubscription = FlutterInappPurchase.instance
    .purchaseUpdated.listen((purchase) {
  if (purchase != null) {
    print('purchase-updated: ${purchase.productId}');
    _handlePurchaseUpdate(purchase);
  }
});

_purchaseErrorSubscription = FlutterInappPurchase.instance
    .purchaseError.listen((error) {
  print('purchase-error: ${error?.message}');
  _handlePurchaseError(error);
});

Step 4: Update Product Fetching

Before:

Future<void> _getProducts() async {
  List<IAPItem> items = await FlutterInappPurchase.instance
      .fetchProducts(skus: _productIds, type: 'inapp');
  setState(() {
    _items = items;
  });
}

After:

Future<void> _getProducts() async {
  final result = await FlutterInappPurchase.instance.fetchProducts(
    ProductRequest(
      skus: _productIds,
      type: ProductQueryType.InApp,
    ),
  );
  setState(() {
    _items = result.value;
  });
}

Step 5: Update Purchase Requests

Before:

void _requestPurchase(IAPItem item) {
  FlutterInappPurchase.instance.requestPurchase(item.productId);
}

After:

Future<void> _requestPurchase(ProductCommon item) async {
  final requestProps = RequestPurchaseProps.inApp(
    request: RequestPurchasePropsByPlatforms(
      apple: RequestPurchaseIosProps(
        sku: item.id,
        quantity: 1,
      ),
      google: RequestPurchaseAndroidProps(
        skus: [item.id],
      ),
    ),
  );

  await FlutterInappPurchase.instance.requestPurchase(requestProps);
}

Step 6: Update Transaction Completion

Before:

// iOS
await FlutterInappPurchase.instance.finishTransaction(item);

// Android
await FlutterInappPurchase.instance.consumePurchase(
  purchaseToken: item.purchaseToken!,
);

After:

// iOS
await FlutterInappPurchase.instance.finishTransaction(
  purchase: item,
  isConsumable: true,
);

// Android
await FlutterInappPurchase.instance.consumePurchaseAndroid(
  purchaseToken: item.purchaseToken!,
);

Step 7: Update Field Access

Before:

final id = product.productId;
final price = product.localizedPrice;

After:

final id = product.id;
final price = product.displayPrice;

Complete Migration Example

Before (v5.x)

class _MyStoreState extends State<MyStore> {
  StreamSubscription? _purchaseSubscription;
  List<IAPItem> _items = [];

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

  Future<void> _init() async {
    await FlutterInappPurchase.instance.initConnection();

    _purchaseSubscription = FlutterInappPurchase.iapUpdated.listen((data) {
      print('purchase: $data');
      _finishTransaction(data);
    });

    final items = await FlutterInappPurchase.instance
        .fetchProducts(skus: _productIds, type: 'inapp');

    setState(() {
      _items = items;
    });
  }

  void _buy(IAPItem item) {
    FlutterInappPurchase.instance.requestPurchase(item.productId);
  }

  void _finishTransaction(Purchase item) {
    FlutterInappPurchase.instance.finishTransaction(item);
  }
}

After (v6.8+)

class _MyStoreState extends State<MyStore> {
  StreamSubscription? _purchaseSubscription;
  List<ProductCommon> _items = [];

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

  Future<void> _init() async {
    await FlutterInappPurchase.instance.initConnection();

    _purchaseSubscription = FlutterInappPurchase.instance
        .purchaseUpdated.listen((purchase) {
      if (purchase != null) {
        print('purchase: ${purchase.productId}');
        _finishTransaction(purchase);
      }
    });

    final result = await FlutterInappPurchase.instance.fetchProducts(
      ProductRequest(
        skus: _productIds,
        type: ProductQueryType.InApp,
      ),
    );

    setState(() {
      _items = result.value;
    });
  }

  Future<void> _buy(ProductCommon item) async {
    final requestProps = RequestPurchaseProps.inApp(
      request: RequestPurchasePropsByPlatforms(
        apple: RequestPurchaseIosProps(
          sku: item.id,
          quantity: 1,
        ),
        google: RequestPurchaseAndroidProps(
          skus: [item.id],
        ),
      ),
    );

    await FlutterInappPurchase.instance.requestPurchase(requestProps);
  }

  Future<void> _finishTransaction(Purchase item) async {
    await FlutterInappPurchase.instance.finishTransaction(
      purchase: item,
      isConsumable: true,
    );
  }

  @override
  void dispose() {
    _purchaseSubscription?.cancel();
    super.dispose();
  }
}

Testing Checklist

After migration, test the following:

• App compiles without errors
• IAP connection initializes successfully
• Products load correctly
• Purchase flow completes
• Transactions finish properly
• Error handling works (test by cancelling a purchase)
• Restore purchases works
• Both iOS and Android platforms tested

Common Migration Issues

Issue 1: "ErrorCode.E_USER_CANCELLED not found"

Solution: Update to new PascalCase format:

ErrorCode.UserCancelled

Issue 2: "productId doesn't exist"

Solution: Change to id:

// Before
item.productId

// After
item.id

Issue 3: "localizedPrice doesn't exist"

Solution: Change to displayPrice:

// Before
item.localizedPrice

// After
item.displayPrice

Issue 4: "type argument required"

Solution: Add ProductQueryType:

ProductRequest(
  skus: ['product_id'],
  type: ProductQueryType.InApp, // Required
)

Benefits of v6.8+

• OpenIAP Standard: Full compliance with OpenIAP specification
• Better Type Safety: Strongly typed APIs with fewer runtime errors
• Improved Error Handling: Clearer error codes and messages
• Modern Platform Support: Latest iOS StoreKit 2 and Android Billing v8
• Better Documentation: Comprehensive guides aligned with OpenIAP
• Cross-Platform Consistency: Unified API across iOS and Android

Need Help?

If you encounter issues during migration:

1. Check the Troubleshooting Guide
2. Review the API Documentation
3. Look at the Examples
4. Open an issue on GitHub
5. Join our Discord Community

Related Documentation

• OpenIAP Specification
• Quick Start Guide
• Error Handling Guide
• Products Guide
• Purchases Guide