Garage-SDKs/garage_iap/example/lib/main.dart

import "package:flutter/material.dart";
import "package:garage_auth/garage_auth.dart";
import "package:garage_iap/garage_iap.dart";

// A tiny store screen: sign in, list products, buy one, show what you own. The
// real wiring (deep-link callback for completeSignIn etc.) is the host app's
// job — see garage_auth's README. This just shows the iap surface.

late final GarageAuth auth;
late final GarageIap iap;

void main() {
  auth = GarageAuth(
    issuer: "https://hub.imbenji.net/auth-api",
    clientId: "example-app",
    redirectUri: "exampleapp://auth/callback",
  );

  iap = GarageIap(
    auth: auth,
    appSlug: "example-app",
    apiBaseUrl: "https://store.imbenji.net/api",
  );

  runApp(const ExampleApp());
}

class ExampleApp extends StatelessWidget {
  const ExampleApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: "garage_iap example",
      theme: ThemeData(useMaterial3: true),
      home: const StorePage(),
    );
  }
}

class StorePage extends StatefulWidget {
  const StorePage({super.key});

  @override
  State<StorePage> createState() => _StorePageState();
}

class _StorePageState extends State<StorePage> {
  List<GarageProduct> _products = [];
  String _status = "";
  bool _busy = false;

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

  Future<void> _boot() async {
    await auth.restore();

    // populate the offline gate cheaply before any network — cachedLicence reads
    // straight from secure storage and verifies locally.
    try {
      await iap.cachedLicence();
    } catch (e) {
      // expired-offline etc. — fine, just means not entitled until we re-fetch.
      print("cached licence not usable: $e");
    }

    if (auth.isSignedIn) {
      await _load();
    }
    if (mounted) setState(() {});
  }

  Future<void> _load() async {
    setState(() => _busy = true);
    try {
      _products = await iap.products();
      await iap.entitlements();
      await iap.licence(); // refresh + cache the offline licence
      _status = "loaded";
    } catch (e) {
      _status = "load failed: $e";
    }
    if (mounted) setState(() => _busy = false);
  }

  Future<void> _buy(GarageProduct p) async {
    setState(() => _busy = true);
    try {
      final outcome = await iap.purchase(p, mode: PurchaseMode.sheet);
      _status = "purchase: ${outcome.name}";
    } on IapError catch (e) {
      _status = "purchase error: ${e.message}";
    } catch (e) {
      _status = "purchase failed: $e";
    }
    if (mounted) setState(() => _busy = false);
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text("Store")),
      body: !auth.isSignedIn
          ? Center(
              child: ElevatedButton(
                onPressed: () => auth.signIn(),
                child: const Text("Sign in with Garage"),
              ),
            )
          : Column(
              children: [
                if (_busy) const LinearProgressIndicator(),
                Padding(
                  padding: const EdgeInsets.all(12),
                  child: Text(_status),
                ),
                Expanded(
                  child: ListView(
                    children: [
                      for (final p in _products)
                        ListTile(
                          title: Text(p.name),
                          subtitle: Text(p.displayPrice),
                          trailing: iap.has(p.sku)
                              ? const Chip(label: Text("Owned"))
                              : FilledButton(
                                  onPressed: () => _buy(p),
                                  child: const Text("Buy"),
                                ),
                        ),
                    ],
                  ),
                ),
              ],
            ),
    );
  }
}