dio_auth_guard 0.0.1

Automatically handles 401/403 responses in Dio — cancels all in-flight requests and navigates to a custom unauthenticated screen. Router-agnostic.

example/lib/main.dart

import 'package:dio/dio.dart';
import 'package:dio_auth_guard/dio_auth_guard.dart';
import 'package:flutter/material.dart';
import 'package:go_router/go_router.dart';

// ---------------------------------------------------------------------------
// Navigator key — shared between AuthGuardConfig and GoRouter so the guard
// can resolve the current context when navigation is needed.
// ---------------------------------------------------------------------------
final GlobalKey<NavigatorState> navigatorKey = GlobalKey<NavigatorState>();

// ---------------------------------------------------------------------------
// Dio instance — register AuthGuardModule after creation.
// ---------------------------------------------------------------------------
final Dio dio = Dio(BaseOptions(baseUrl: 'https://api.example.com'));

// ---------------------------------------------------------------------------
// GoRouter
// ---------------------------------------------------------------------------
final GoRouter router = GoRouter(
  navigatorKey: navigatorKey,
  initialLocation: '/home',
  routes: [
    GoRoute(
      path: '/login',
      builder: (_, __) => const LoginScreen(),
    ),
    GoRoute(
      path: '/home',
      builder: (_, __) => const HomeScreen(),
    ),
  ],
);

// ---------------------------------------------------------------------------
// main()
// ---------------------------------------------------------------------------
void main() {
  // ── Option A: GoRouter (active) ──────────────────────────────────────────
  // Use onUnauthenticated when your app uses a declarative router.
  // The callback lets the router manage the navigation stack itself.
  AuthGuardConfig.init(
    navigatorKey: navigatorKey,
    onUnauthenticated: () {
      navigatorKey.currentContext?.go('/login');
    },
  );

  // ── Option B: Plain Navigator (commented out) ────────────────────────────
  // Use unauthWidget when your app uses Flutter's built-in Navigator.
  // AuthGuard will call pushAndRemoveUntil, clearing the entire back-stack.
  //
  // AuthGuardConfig.init(
  //   navigatorKey: navigatorKey,
  //   unauthWidget: const LoginScreen(),
  // );

  // Register the interceptor on the Dio instance.
  AuthGuardModule.register(dio);

  runApp(const ExampleApp());
}

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp.router(
      title: 'dio_auth_guard example',
      routerConfig: router,
      debugShowCheckedModeBanner: false,
    );
  }
}

// ---------------------------------------------------------------------------
// HomeScreen
// ---------------------------------------------------------------------------
class HomeScreen extends StatelessWidget {
  const HomeScreen({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('dio_auth_guard example')),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            const Text(
              'Home Screen — authenticated',
              style: TextStyle(fontSize: 18),
            ),
            const SizedBox(height: 32),
            ElevatedButton(
              onPressed: () {
                // Simulates receiving a 401 response — in a real app this is
                // triggered automatically by AuthInterceptor. Useful for
                // manually testing the guard without a real backend.
                AuthGuard.instance.handleUnauthenticated();
              },
              child: const Text('Simulate 401 — trigger guard'),
            ),
          ],
        ),
      ),
    );
  }
}

// ---------------------------------------------------------------------------
// LoginScreen
// ---------------------------------------------------------------------------
class LoginScreen extends StatefulWidget {
  const LoginScreen({super.key});

  @override
  State<LoginScreen> createState() => _LoginScreenState();
}

class _LoginScreenState extends State<LoginScreen> {
  final _emailController = TextEditingController();
  final _passwordController = TextEditingController();

  @override
  void dispose() {
    _emailController.dispose();
    _passwordController.dispose();
    super.dispose();
  }

  void _onLogin() {
    // In a real app: await your auth API call here, then on success:
    //   1. Store tokens.
    //   2. Call AuthGuard.onLoginSuccess() to re-arm the guard.
    //   3. Navigate to the authenticated area.
    AuthGuard.onLoginSuccess();
    context.go('/home');
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Login')),
      body: Padding(
        padding: const EdgeInsets.all(24),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            TextField(
              controller: _emailController,
              decoration: const InputDecoration(
                labelText: 'Email',
                border: OutlineInputBorder(),
              ),
              keyboardType: TextInputType.emailAddress,
            ),
            const SizedBox(height: 16),
            TextField(
              controller: _passwordController,
              decoration: const InputDecoration(
                labelText: 'Password',
                border: OutlineInputBorder(),
              ),
              obscureText: true,
            ),
            const SizedBox(height: 24),
            SizedBox(
              width: double.infinity,
              child: ElevatedButton(
                onPressed: _onLogin,
                child: const Text('Login'),
              ),
            ),
          ],
        ),
      ),
    );
  }
}