Class called twice after authstatechanges is implemented

Question

After i tried to implement the authStateChanges.listen() for managing user sessions, the class was called twice and it results in 2 Alert Dialogs of the same content, i dont understand what is going on, why is it called twice.

main() function:

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  runApp(MaterialApp(home: EntryPoint(), debugShowCheckedModeBanner: false));
}

[EDITED] EntryPoint class:

class EntryPoint extends StatefulWidget {
  _EntryPointState createState() => _EntryPointState();
}

class _EntryPointState extends State<EntryPoint> {
  // Set default `_initialized` and `_error` state to false
  bool _initialized = false;
  bool _error = false;
  FirebaseApp firebaseApp;

  // Define an async function to initialize FlutterFire
  void initializeFlutterFire() async {
    try {
      // Wait for Firebase to initialize and set `_initialized` state to true
      firebaseApp = await Firebase.initializeApp();
      setState(() {
        _initialized = true;
      });
    } catch (e) {
      // Set `_error` state to true if Firebase initialization fails
      setState(() {
        _error = true;
      });
    }
    FirebaseAuth.instance.authStateChanges().listen((User user) {
      if (user == null) {
        Navigator.push(context,
            MaterialPageRoute(builder: (BuildContext context) => LoginPage()));
      } else {
        Navigator.push(context,
            MaterialPageRoute(builder: (BuildContext context) => MyApp()));
            print('ok');
      }
    });
  }

  @override
  void initState() {
    this.initializeFlutterFire();
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    SystemChrome.setPreferredOrientations([DeviceOrientation.portraitUp]);

    return _getLandingPage();
  }
}

it logged twice 'ok' in the debug console

Restarted application in 1,630ms.
D/ConnectivityManager(27325): unregisterNetworkCallback; CallingUid : 10392, CallingPid : 27325
D/ConnectivityManager(27325): unregisterNetworkCallback; CallingUid : 10392, CallingPid : 27325
W/example.confAp(27325): Accessing hidden method Ldalvik/system/CloseGuard;->close()V (light greylist, linking)
I/flutter (27325): ok
I/flutter (27325): ok
I/flutter (27325): IT IS CONNECTED BOYS
D/ConnectivityManager(27325): requestNetwork; CallingUid : 10392, CallingPid : 27325
W/DynamiteModule(27325): Local module descriptor class for providerinstaller not found.
I/flutter (27325): IT IS CONNECTED BOYS
I/DynamiteModule(27325): Considering local module providerinstaller:0 and remote module providerinstaller:0
W/ProviderInstaller(27325): Failed to load providerinstaller module: No acceptable module found. Local version is 0 and remote version is 0.
D/ConnectivityManager(27325): requestNetwork; CallingUid : 10392, CallingPid : 27325

Edit : added StreamBuilder

Widget _getLandingPage() {
  return StreamBuilder<User>(
    stream: FirebaseAuth.instance.authStateChanges(),
    builder: (BuildContext context, snapshot) {
      if (snapshot.hasData) {
        return MyApp();
      } else {
        return LoginPage();
      }
    },
  );
}

Solution

Maybe, it is the problem that you call SystemChrome.setPreferredOrientations([DeviceOrientation.portraitUp]); inside build method. Try to remove it.

The second one, it seems like that problem is related to calling method in initState. Try to use StreamBuilder to listen Authentication changes from Firebase. Apply the same logic for StreamBuilder.

Comments

[Admin]

FirebaseAuth.instance.authStateChanges().dislinct().listen blabla

[ETCasual]

i have added StreamBuilder to listen for auth changes and my codes is as edited in the main question.. but however it shows LoginPage() for a split second and then shows MyApp(), is there any workaround?

[thisisyusub]

That is okey, because you have not authenticated. You can delay it using Future. Maybe it can help you to increase showing time of LoginPage. dart import 'dart:async'; void main() async { getValue().listen((data) => print(data)); } Stream<int> getValue() async* { await Future.delayed(Duration(seconds: 2)); yield* authStateChanges(); } Stream<int> authStateChanges() async* { yield 5; } Here, instead of listen you will use Streambuilder.