go_router After trying to open the app from a Dynamic link - Unhandled Exception: This widget has been unmounted, so the State no longer has a context

Question

I am using Flutter + go_router 3.0 + Flutterflow + Firebase (to create my dynamic link). The app is working perfectly fine. My problem comes from when a user clicks on a Dynamic link and the app opens and I got an error (see below). It only shows this error when the app is opened from a Dynamic link which was generated from Firebase, example - app.page.link/settings I saw many questions here and I know what it should be done in general, but I still need some guideline of what example should be changed and where is the error coming from.

Here is my code

import 'package:firebase_core/firebase_core.dart';
import 'package:flutter/material.dart';
import 'package:flutter_localizations/flutter_localizations.dart';
import 'package:go_router/go_router.dart';
import 'package:kulturno_mi_e/login/login_widget.dart';
import 'package:kulturno_mi_e/splash_screen/splash_screen_widget.dart';
import 'package:provider/provider.dart';

import 'auth/auth_util.dart';
import 'auth/firebase_user_provider.dart';
import 'favourites/favourites_widget.dart';
import 'flutter_flow/flutter_flow_theme.dart';
import 'flutter_flow/internationalization.dart';
import 'home/home_widget.dart';
import 'settings/settings_widget.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();

  await FlutterFlowTheme.initialize();

  runApp(MyApp());
}

class LoginInfo extends ChangeNotifier {
  var _userName = '';
  String get userName => _userName;
  bool get loggedIn => _userName.isNotEmpty;
  // set loggedIn(bool loginStatus) {
  //   loggedIn = loginStatus;
  // }

  void login(String userName) {
    _userName = userName;
    notifyListeners();
  }

  void logout() {
    _userName = '';
    notifyListeners();
  }
}

class MyApp extends StatefulWidget {
  // This widget is the root of your application.
  @override
  _MyAppState createState() => _MyAppState();

  static _MyAppState of(BuildContext context) =>
      context.findAncestorStateOfType<_MyAppState>();
}

class _MyAppState extends State<MyApp> {
  Locale _locale;
  ThemeMode _themeMode = FlutterFlowTheme.themeMode;
  Stream<KulturnoMiEFirebaseUser> userStream;
  KulturnoMiEFirebaseUser initialUser;
  bool displaySplashImage = true;
  final authUserSub = authenticatedUserStream.listen((_) {});

  void setLocale(Locale value) => setState(() => _locale = value);
  void setThemeMode(ThemeMode mode) => setState(() {
        _themeMode = mode;
        FlutterFlowTheme.saveThemeMode(mode);
      });

  @override
  void initState() {
    super.initState();
    userStream = kulturnoMiEFirebaseUserStream()
      ..listen((user) => initialUser ?? setState(() => initialUser = user));

    Future.delayed(
        Duration(seconds: 1), () => setState(() => displaySplashImage = false));
  }

  @override
  void dispose() {
    authUserSub.cancel();

    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final _loginInfo = LoginInfo();

    final GoRouter _router = GoRouter(

      initialLocation: '/events',
      // redirect to the login page if the user is not logged in
      redirect: (state) {
        // if the user is not logged in, they need to login
        // final loggedIn = _loginInfo.loggedIn;
        final loggedIn = currentUser == null ? false : currentUser.loggedIn;
        final loggingIn = state.subloc == '/login';

        // bundle the location the user is coming from into a query parameter
        // TODO: Chane '/' with the "Entry Page"
        final fromp = state.subloc == '/' ? '' : '?from=${state.subloc}';

        if (!loggedIn) return loggingIn ? null : '/login$fromp';

        // if the user is logged in, send them where they were going before (or
        // home if they weren't going anywhere)
        if (loggingIn) return state.queryParams['from'] ?? '/events';

        // no need to redirect at all
        return null;
      },
      // changes on the listenable will cause the router to refresh it's route
      refreshListenable: _loginInfo,
      debugLogDiagnostics: true,
      routes: <GoRoute>[
        GoRoute(
          path: '/',
          builder: (BuildContext context, GoRouterState state) =>
              const SplashScreenWidget(),
        ),
        GoRoute(
          path: '/login',
          builder: (BuildContext context, GoRouterState state) =>
              const LoginWidget(),
        ),
        GoRoute(
          path: '/events',
          builder: (BuildContext context, GoRouterState state) =>
              // TODO: In this demo I use NavBar, but it can be also normal - const PageWidget(),
              NavBarPage(initialPage: 'home'),
        ),
        GoRoute(
          name: '/settings',
          path: '/settings',
          builder: (BuildContext context, GoRouterState state) =>
              NavBarPage(initialPage: 'settings'),
        ),
      ],
      errorBuilder: (context, state) => Text('ERROR! PAGE NOT FOUND!'),
    );

    // final router = GoRouter.of(context);
    // print(['ROUTER!!! ', _router.location]);

    return ChangeNotifierProvider<LoginInfo>.value(
      value: _loginInfo,
      child: MaterialApp.router(
        title: 'Kulturno mi e',
        localizationsDelegates: [
          FFLocalizationsDelegate(),
          GlobalMaterialLocalizations.delegate,
          GlobalWidgetsLocalizations.delegate,
          GlobalCupertinoLocalizations.delegate,
        ],
        locale: _locale,
        supportedLocales: const [Locale('en', '')],
        theme: ThemeData(brightness: Brightness.light),
        darkTheme: ThemeData(brightness: Brightness.dark),
        themeMode: _themeMode,
        routeInformationParser: _router.routeInformationParser,
        routerDelegate: _router.routerDelegate,
        //   home: initialUser == null || displaySplashImage
        //       ? Container(
        //           color: Colors.transparent,
        //           child: Builder(
        //             builder: (context) => Image.asset(
        //               'assets/images/photo_2022-03-24_12-00-45.jpg',
        //               fit: BoxFit.contain,
        //             ),
        //           ),
        //         )
        //       : currentUser.loggedIn
        //           ? NavBarPage()
        //           : SplashScreenWidget(),
      ),
    );
  }
}

class NavBarPage extends StatefulWidget {
  NavBarPage({Key key, this.initialPage}) : super(key: key);

  final String initialPage;

  @override
  _NavBarPageState createState() => _NavBarPageState();
}

/// This is the private State class that goes with NavBarPage.
class _NavBarPageState extends State<NavBarPage> {
  String _currentPage = 'home';

  @override
  void initState() {
    super.initState();
    _currentPage = widget.initialPage ?? _currentPage;
  }

  @override
  Widget build(BuildContext context) {
    final tabs = {
      'home': HomeWidget(),
      'favourites': FavouritesWidget(),
      'settings': SettingsWidget(),
    };
    final currentIndex = tabs.keys.toList().indexOf(_currentPage);
    return Scaffold(
      body: tabs[_currentPage],
      bottomNavigationBar: BottomNavigationBar(
        currentIndex: currentIndex,
        onTap: (i) => setState(() => _currentPage = tabs.keys.toList()[i]),
        backgroundColor: Colors.black,
        selectedItemColor: Colors.white,
        unselectedItemColor: Color(0xFF57636C),
        showSelectedLabels: false,
        showUnselectedLabels: false,
        type: BottomNavigationBarType.fixed,
        items: <BottomNavigationBarItem>[
          BottomNavigationBarItem(
            icon: Icon(
              Icons.home_outlined,
              size: 24,
            ),
            activeIcon: Icon(
              Icons.home,
              size: 24,
            ),
            label: 'Начало',
            tooltip: '',
          ),
          BottomNavigationBarItem(
            icon: Icon(
              Icons.favorite_border,
              size: 24,
            ),
            activeIcon: Icon(
              Icons.favorite,
              size: 24,
            ),
            label: 'Известия',
            tooltip: '',
          ),
          BottomNavigationBarItem(
            icon: Icon(
              Icons.settings_outlined,
              size: 24,
            ),
            activeIcon: Icon(
              Icons.settings,
              size: 24,
            ),
            label: 'Настройки',
            tooltip: '',
          )
        ],
      ),
    );
  }
}

This is the error I got

E/flutter (23539): [ERROR:flutter/lib/ui/ui_dart_state.cc(198)] Unhandled Exception: This widget has been unmounted, so the State no longer has a context (and should be considered defunct).
E/flutter (23539): Consider canceling any active work during "dispose" or using the "mounted" getter to determine if the State is still active.
E/flutter (23539): #0      State.context.<anonymous closure> (package:flutter/src/widgets/framework.dart:929:9)
E/flutter (23539): #1      State.context (package:flutter/src/widgets/framework.dart:935:6)
E/flutter (23539): #2      _DynamicLinksState.initDynamicLinks.<anonymous closure> (package:kulturno_mi_e/custom_code/widgets/dynamic_links.dart:48:27)
E/flutter (23539): #3      _rootRunUnary (dart:async/zone.dart:1434:47)
E/flutter (23539): #4      _CustomZone.runUnary (dart:async/zone.dart:1335:19)
E/flutter (23539): #5      _CustomZone.runUnaryGuarded (dart:async/zone.dart:1244:7)
E/flutter (23539): #6      _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:341:11)
E/flutter (23539): #7      _DelayedData.perform (dart:async/stream_impl.dart:591:14)
E/flutter (23539): #8      _StreamImplEvents.handleNext (dart:async/stream_impl.dart:706:11)
E/flutter (23539): #9      _PendingEvents.schedule.<anonymous closure> (dart:async/stream_impl.dart:663:7)
E/flutter (23539): #10     _rootRun (dart:async/zone.dart:1418:47)
E/flutter (23539): #11     _CustomZone.run (dart:async/zone.dart:1328:19)
E/flutter (23539): #12     _CustomZone.runGuarded (dart:async/zone.dart:1236:7)
E/flutter (23539): #13     _CustomZone.bindCallbackGuarded.<anonymous closure> (dart:async/zone.dart:1276:23)
E/flutter (23539): #14     _rootRun (dart:async/zone.dart:1426:13)
E/flutter (23539): #15     _CustomZone.run (dart:async/zone.dart:1328:19)
E/flutter (23539): #16     _CustomZone.runGuarded (dart:async/zone.dart:1236:7)
E/flutter (23539): #17     _CustomZone.bindCallbackGuarded.<anonymous closure> (dart:async/zone.dart:1276:23)
E/flutter (23539): #18     _microtaskLoop (dart:async/schedule_microtask.dart:40:21)
E/flutter (23539): #19     _startMicrotaskLoop (dart:async/schedule_microtask.dart:49:5)
E/flutter (23539): 
E/flutter (23539): [ERROR:flutter/shell/common/shell.cc(93)] Dart Unhandled Exception: This widget has been unmounted, so the State no longer has a context (and should be considered defunct).
E/flutter (23539): Consider canceling any active work during "dispose" or using the "mounted" getter to determine if the State is still active., stack trace: #0      State.context.<anonymous closure> (package:flutter/src/widgets/framework.dart:929:9)
E/flutter (23539): #1      State.context (package:flutter/src/widgets/framework.dart:935:6)
E/flutter (23539): #2      _DynamicLinksState.initDynamicLinks.<anonymous closure> (package:kulturno_mi_e/custom_code/widgets/dynamic_links.dart:48:27)
E/flutter (23539): #3      _rootRunUnary (dart:async/zone.dart:1442:13)
E/flutter (23539): #4      _RootZone.runUnaryGuarded (dart:async/zone.dart:1621:7)
E/flutter (23539): #5      _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:341:11)
E/flutter (23539): #6      _DelayedData.perform (dart:async/stream_impl.dart:591:14)
E/flutter (23539): #7      _StreamImplEvents.handleNext (dart:async/stream_impl.dart:706:11)
E/flutter (23539): #8      _PendingEvents.schedule.<anonymous closure> (dart:async/stream_impl.dart:663:7)
E/flutter (23539): #9      _rootRun (dart:async/zone.dart:1418:47)
E/flutter (23539): #10     _CustomZone.run (dart:async/zone.dart:1328:19)
E/flutter (23539): #11     _CustomZone.runGuarded (dart:async/zone.dart:1236:7)
E/flutter (23539): #12     _CustomZone.bindCallbackGuarded.<anonymous closure> (dart:async/zone.dart:1276:23)
E/flutter (23539): #13     _rootRun (dart:async/zone.dart:1426:13)
E/flutter (23539): #14     _CustomZone.run (dart:async/zone.dart:1328:19)
E/flutter (23539): #15     _CustomZone.runGuarded (dart:async/zone.dart:1236:7)
E/flutter (23539): #16     _CustomZone.bindCallbackGuarded.<anonymous closure> (dart:async/zone.dart:1276:23)
E/flutter (23539): #17     _microtaskLoop (dart:async/schedule_microtask.dart:40:21)
E/flutter (23539): #18     _startMicrotaskLoop (dart:async/schedule_microtask.dart:49:5)
E/flutter (23539):