[go_router] Fix Popping state and re-rendering scaffold at the same time doesn't update the URL on web #150312

[ahyangnb]

Change the 3 file palce, because issue #150312

The reason for the issue is when call counterStream.increment(); will notify notifyListeners() of StreamListener, and finally affect _handleRouteInformationProviderNotification of _RouterState in packages/flutter/lib/src/widgets/router.dart.

When pop should not call _handleRouteInformationProviderNotification otherwise will be path wrong.
because the value of GoRouteInformationProvider is not the latest.

solution:
always make the value of GoRouteInformationProvider knew the latest RouteInformation[but not to do notifyListeners()].

i don't know if adding pop to NavigatingType is reasonable, if any place needs to be changed please tell me.

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[ahyangnb]

Is this a big deal?

[ahyangnb]

Is this a big deal?

this email is my new computer set, i was forget to set, but know, i've set.

[chunhtai]

This may not work if the routerDelegate.pop removes pageless route such as dialog or modalbottomroute.

[ahyangnb]

I've try use go_router 14.2.0 of pub.dev and run demo follwing code also not work, I thought it was normal, see the picture above.

if misundestand please tell me how reproduce it.

demo code:

import 'dart:async';

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

class CounterStream {
  int _counter = 0;

  final _streamController = StreamController<int>.broadcast();

  Stream<int> get stateStream => _streamController.stream.asBroadcastStream();

  void increment() {
    _streamController.sink.add(++_counter);
  }

  Future<void> delayedRerender() async {
    increment();
    increment();
  }

  void dispose() {
    _streamController.close();
  }
}

final CounterStream counterStream = CounterStream();

class StreamListener extends ChangeNotifier {
  StreamListener(Stream<dynamic> stream) {
    notifyListeners();

    _subscription = stream.asBroadcastStream().listen((_) {
      notifyListeners();
    });
  }

  late final StreamSubscription<dynamic> _subscription;

  @override
  void notifyListeners() {
    super.notifyListeners();
    print('refreshing the router');
  }

  @override
  void dispose() {
    _subscription.cancel();
    super.dispose();
  }
}

void main() {
  GoRouter.optionURLReflectsImperativeAPIs = true;

  WidgetsFlutterBinding.ensureInitialized();

  runApp(const MyApp());
}

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

  @override
  State<MyApp> createState() => _MyAppState();
}

final _rootNavigatorKey = GlobalKey<NavigatorState>();

final GoRouter _router = GoRouter(
  initialLocation: '/',
  navigatorKey: _rootNavigatorKey,
  refreshListenable: StreamListener(counterStream.stateStream),
  routes: <RouteBase>[
    ShellRoute(
      builder: (context, state, child) {
        return GenericPage(child: child);
      },
      routes: [
        GoRoute(
          path: '/',
          builder: (BuildContext context, GoRouterState state) =>
              const GenericPage(showPushButton: true, path: 'a'),
          routes: [
            GoRoute(
              path: 'a',
              name: 'a',
              builder: (BuildContext context, GoRouterState state) =>
                  const GenericPage(showPushButton: true, path: 'b'),
              routes: [
                GoRoute(
                  path: 'b',
                  name: 'b',
                  builder: (BuildContext context, GoRouterState state) =>
                      const GenericPage(showBackButton: true),
                ),
              ],
            ),
          ],
        ),
      ],
    ),
  ],
);

class _MyAppState extends State<MyApp> {
  late StreamSubscription<int> _stateSubscription;
  int _currentState = 0;

  @override
  void initState() {
    super.initState();
    _stateSubscription = counterStream.stateStream.listen((state) {
      setState(() {
        _currentState = state;
      });
    });
  }

  @override
  void dispose() {
    _stateSubscription.cancel();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp.router(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      routerConfig: _router,
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return Material(
      type: MaterialType.transparency,
      child: Center(
        child: Container(
          color: Colors.white,
          width: 300,
          height: 300,
          alignment: Alignment.center,
          child: Column(
            children: ['Navigator::pop', 'GoRouter::pop'].map((e) {
              return InkWell(
                child: Row(children: [
                  Text(e),
                  const Icon(Icons.close),
                ]),
                onTap: () {
                  if (e == 'GoRouter::pop') {
                    GoRouter.of(context).pop();
                  } else {
                    Navigator.of(context).pop();
                  }
                },
              );
            }).toList(),
          ),
        ),
      ),
    );
  }
}

class GenericPage extends StatefulWidget {
  final Widget? child;
  final bool showPushButton;
  final bool showBackButton;
  final String? path;

  const GenericPage({
    this.child,
    Key? key,
    this.showPushButton = false,
    this.showBackButton = false,
    this.path,
  }) : super(key: key ?? const ValueKey<String>('ShellWidget'));

  @override
  State<GenericPage> createState() => _GenericPageState();
}

class _GenericPageState extends State<GenericPage> {
  late StreamSubscription<int> _stateSubscription;
  int _currentState = 0;

  @override
  void initState() {
    super.initState();
    _stateSubscription = counterStream.stateStream.listen((state) {
      setState(() {
        _currentState = state;
      });
    });
  }

  @override
  void dispose() {
    _stateSubscription.cancel();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: widget.child != null
            ? AppBar(
                title: Text('Count: $_currentState'),
                actions: [
                  TextButton(
                    onPressed: () {
                      showDialog(
                        context: context,
                        builder: (context) {
                          return DialogTest();
                        },
                      );
                    },
                    child: const Text('dialog1'),
                  ),
                  TextButton(
                    onPressed: () {
                      showModalBottomSheet(
                        context: context,
                        builder: (context) {
                          return DialogTest();
                        },
                      );
                    },
                    child: const Text('dialog2'),
                  )
                ],
              )
            : null,
        body: _buildWidget(context));
  }

  Widget _buildWidget(BuildContext context) {
    if (widget.child != null) {
      return widget.child!;
    }

    if (widget.showBackButton) {
      return TextButton(
        onPressed: () {
          // WHEN THE USER PRESSES THIS BUTTON, THE URL
          // DOESN'T CHANGE, BUT THE SCREEN DOES
          counterStream
              .increment(); // <- when removing this line the issue is gone
          GoRouter.of(context).pop();
        },
        child: const Text('<- Go Back'),
      );
    }

    if (widget.showPushButton) {
      return TextButton(
        onPressed: () {
          GoRouter.of(context).goNamed(widget.path!);
        },
        child: const Text('Push ->'),
      );
    }

    return Text('Current state: $_currentState');
  }
}

[chunhtai]

I have not looked into it more, but we can't guarantee the goRouter.pop will pop the last routematch.

[ahyangnb]

we can guarantee the goRouter.pop will pop the last routematch, because we just mark the RouteInformation in GoRouteInformationProvider, the pop will use navigatorKey to pop the router and use currentConfiguration of GoRouterDelegate to check last router and we have no change currentConfiguration GoRouterDelegate value.

pop of NavigatorState won't be affected either.

[ahyangnb]

value of GoRouteInformationProvider is self-management, will not use it outside.

so you can check the GoRouteInformationProvider in packages/go_router/lib/src/information_provider.dart

[chunhtai]

What I meant is that the pop can pop a dialog instead of the page. It is also possible that the page can contain localhistory, such as open drawer.

[chunhtai]

This seemed not addressed?

[ahyangnb]

I will continue to look into this.

[chunhtai]

Hi @ahyangnb Are you still planning on coming back to this pr?

[ahyangnb]

Hi @ahyangnb Are you still planning on coming back to this pr?
yes