supabase_flutter_web_auth 0.2.0

Runs supabase_flutter's OAuth, SSO, and identity-linking flows through a system web authentication session instead of a plain browser launch.

example/lib/main.dart

import 'dart:async';

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:supabase_flutter/supabase_flutter.dart';
import 'package:supabase_flutter_web_auth/supabase_flutter_web_auth.dart';

Future<void> main() async {
  await Supabase.initialize(
    url: 'SUPABASE_URL',
    publishableKey: 'SUPABASE_PUBLISHABLE_KEY',
    authOptions: const FlutterAuthClientOptions(
      oauthLauncher: FlutterWebAuth2OAuthLauncher(),
    ),
  );
  runApp(const MyApp());
}

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

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      title: 'supabase_flutter_web_auth Demo',
      home: MyHomePage(),
    );
  }
}

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

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  User? _user;
  StreamSubscription<AuthState>? _authSubscription;

  @override
  void initState() {
    super.initState();
    _user = Supabase.instance.client.auth.currentUser;
    _authSubscription = Supabase.instance.client.auth.onAuthStateChange.listen(
      (data) {
        setState(() {
          _user = data.session?.user;
        });
      },
      onError: (Object error, StackTrace stackTrace) {
        if (!mounted) return;
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('Authentication error: $error')),
        );
      },
    );
  }

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('OAuth via web auth session')),
      body: _user == null ? const _SignInForm() : _SignedInView(user: _user!),
    );
  }
}

class _SignInForm extends StatelessWidget {
  const _SignInForm();

  Future<void> _signInWithGitHub(BuildContext context) async {
    final messenger = ScaffoldMessenger.of(context);
    try {
      final launched = await Supabase.instance.client.auth.signInWithOAuth(
        OAuthProvider.github,
        redirectTo: kIsWeb
            ? null
            : 'io.supabase.flutterwebauthexample://oauth-callback',
      );
      if (!launched) {
        messenger.showSnackBar(
          const SnackBar(content: Text('Sign-in was cancelled')),
        );
      }
    } on Object catch (error) {
      messenger.showSnackBar(
        SnackBar(content: Text('Could not start sign-in: $error')),
      );
    }
  }

  @override
  Widget build(BuildContext context) {
    return Center(
      child: ElevatedButton(
        onPressed: () => unawaited(_signInWithGitHub(context)),
        child: const Text('Sign in with GitHub'),
      ),
    );
  }
}

class _SignedInView extends StatelessWidget {
  const _SignedInView({required this.user});

  final User user;

  @override
  Widget build(BuildContext context) {
    return Center(
      child: Column(
        mainAxisSize: MainAxisSize.min,
        spacing: 16,
        children: [
          Text('Signed in as ${user.email}'),
          TextButton(
            onPressed: () => unawaited(
              Supabase.instance.client.auth.signOut(),
            ),
            child: const Text('Sign out'),
          ),
        ],
      ),
    );
  }
}