The Easiest Implementation of Subscriptions for Flutter

Add the plugin to your Flutter app:

 $ flutter pub add linkfive_purchases

Getting Started

Initialize the SDK. Read our more detailed docs

await LinkFivePurchases.init("LinkFive Api Key");

Get your API key after Sign up. It's free!

Fetch all available subscriptions from LinkFive. The result will be passed to the stream or returned as a Future. Fetch Docs

LinkFivePurchases.fetchProducts();

// or also

LinkFiveProducts? products = await LinkFivePurchases.fetchProducts();

Product Streams

LinkFive mainly uses streams to send data to your application. Active Subscriptions Docs

// Stream of subscriptions to offer to the user
LinkFivePurchases.products

// Stream of purchased subscriptions
LinkFivePurchases.activeProducts

// to listen to a stream do the following:
LinkFivePurchases.products.listen((LinkFiveProducts products) {
  print(products);
});

// or for all active Products
LinkFivePurchases.activeProducts.listen((LinkFiveActiveProducts activeProducts) {
  print(activeProducts);
});

Purchase a Subscription

Simply call purchase with the productDetails from the retrieved subscriptions. Purchase Docs

await LinkFivePurchases.purchase( productDetails );

Restore a Purchases

All restored subscriptions will be available through activeProducts. Restore Docs

LinkFivePurchases.restore();

Switch from one subscription plan to another

You can switch from one Subscription plan to another. Example: from currently a 1 month subscription to a 3 months subscription.

On iOS: you can only switch to a plan which is in the same Subscription Family

The Proration Mode is Google Only. On default, it replaces immediately the subscription and the remaining time will be prorated and credited to the user. You can specify a different proration mode.

LinkFivePurchases.switchPlan(
  oldPurchaseDetails, 
  linkFiveProductDetails.productDetails,
  prorationMode: ProrationMode.immediateWithTimeProration
);

Provider usage

We offer a Provider Plugin which you can implement and use out of the box or you can create your own provider.

LinkFive Provider Package

Check out linkfive_purchases_provider

You just have to register the Provider with our API key and you're all set to use it

MultiProvider(
  providers: [
    // ...
    ChangeNotifierProvider(
      create: (context) => LinkFiveProvider("API_KEY"),
      lazy: false,
    ),
  ]
)

Provider example

class LinkFiveProvider extends ChangeNotifier {
  LinkFivePurchasesMain linkFivePurchases = LinkFivePurchasesMain();

  LinkFiveProducts? products;
  LinkFiveActiveProducts? activeProducts;

  List<StreamSubscription> _streams = [];

  LinkFiveProvider() {
    linkFivePurchases.init("keys.linkFiveApiKey");
    linkFivePurchases.fetchProducts();
    _streams.add(linkFivePurchases.products.listen(_productsUpdate));
    _streams.add(linkFivePurchases.activeProducts.listen(_activeProductsUpdate));
  }

  void _productsUpdate(LinkFiveProducts data) async {
    products = data;
    notifyListeners();
  }

  void _activeProductsUpdate(LinkFiveActiveProducts data) {
    activeProducts = data;
    notifyListeners();
  }

  Future<LinkFiveProducts?> fetchProducts() {
    return LinkFivePurchases.fetchProducts();
  }

  restoreSubscriptions() {
    return LinkFivePurchases.restore();
  }

  Future<bool> purchase(ProductDetails productDetail) async {
    return LinkFivePurchases.purchase(productDetail);
  }

  switchPlan(LinkFivePlan oldPurchasePlan, LinkFiveProductDetails productDetails,
      {ProrationMode? prorationMode}) {
    return LinkFivePurchases.switchPlan(oldPurchasePlan, productDetails,
        prorationMode: prorationMode);
  }

  @override
  void dispose() {
    _streams.forEach((element) async {
      await element.cancel();
    });
    _streams = [];
    super.dispose();
  }
}

StreamBuilder Example

If you're mainly using a StreamBuilder. You can implement LinkFive in the following way:

Show all available Products:

StreamBuilder<LinkFiveProducts>(
  stream: LinkFivePurchases.products,
  builder: (context, snapshot) {
    if (snapshot.hasData) {
     var productData = snapshot.data;
      if(productData != null) {
      // productData to offer
     }
    }
  return Center(child: Text('Loading...'));
  })

Get all Active products

StreamBuilder<LinkFiveActiveProducts>(
  stream: LinkFivePurchases.activeProducts,
  builder: (BuildContext context, snapshot) {
    if (snapshot.hasData) {
      var activeProductsData = snapshot.data;
      if (activeProductsData != null) {
        // activeProductsData to offer
      }
    }
    return Center(child: Text('Loading...'));
  },
)

Easy Integration with the Paywall UI package

Integrate linkfive_purchases with package in_app_purchases_paywall_ui.

it's working with just passing the LinkFive client to the UI library
Automatic purchase state management
The UI is fully customizable
You can control the UI on our Website

Purchase Page

Success Page

Page State Management

Example usage with Paywall UI

usage with in_app_purchases_paywall_ui.

// get subscription data from your provider or from your stream (as described above)
LinkFiveProducts? products = // your products you got through the products Stream

SimplePaywall(
  // ...
  // basically just the linkFivePurchases class
  callbackInterface: LinkFivePurchases.callbackInterface,

  // you can use your own strings or use the intl package to automatically generate the subscription strings
  subscriptionListData: products?.paywallUIHelperData(context: context) ?? [],
  // ...
);

That‘s it. Now the page will automatically offer the subscriptions to the user or if the user already bought the subscription, the paywall will show the success page.

LinkFive/flutter-purchases-sdk