Widget cannot be marked as needing to build because the framework is already in the process of building widgets

Question

I'm trying to implement Provider and it seems it works fine but I get this message:

This _DefaultInheritedProviderScope widget cannot be marked as needing to build because the framework is already in the process of building widgets. A widget can be marked as needing to be built during the build phase only if one of its ancestors is currently building. This exception is allowed because the framework builds parent widgets before children, which means a dirty descendant will always be built. Otherwise, the framework might not visit this widget during this build phase. The widget on which setState() or markNeedsBuild() was called was: _DefaultInheritedProviderScope value: Instance of 'UserProfile' listening to value The widget which was currently being built when the offending call was made was: FutureBuilder dirty state: _FutureBuilderState#bf6ec When the exception was thrown, this was the stack:

0 Element.markNeedsBuild. (package:flutter/src/widgets/framework.dart:3896:11)

1 Element.markNeedsBuild (package:flutter/src/widgets/framework.dart:3911:6)

2 _InheritedProviderScopeMixin.markNeedsNotifyDependents (package:provider/src/inherited_provider.dart:268:5)

3 ChangeNotifier.notifyListeners (package:flutter/src/foundation/change_notifier.dart:206:21)

4 UserProfile.user= (package:mdd/core/services/user_info.dart:13:5) ... The UserProfile

sending notification was: Instance of 'UserProfile'

My code is the following:

class HomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final authService = Provider.of<AuthService>(context);
    final userProfile =    Provider.of<UserProfile>(context);

    return StatefulWrapper(
      onInit: () {
        FirebaseNotifications().setUpFirebase();
      },
      child: FutureBuilder<User>(
        future: authService.getUser(),
        builder: (context, AsyncSnapshot<User> snapshot) {
          if (snapshot.connectionState == ConnectionState.done) {
            if (snapshot.error != null) {
              return Text(snapshot.error.toString());
            }
            userProfile.user = snapshot.data;
           // FirebaseUser user = snapshot.data;

            return snapshot.hasData ? ListScreen() : LoginScreen();
          } else {
            return Scaffold(
              appBar: AppBar(),
              body: Container(),
            );
          }
        },
      )
    );
  }
}

And this is the UserProfile class:

class UserProfile with ChangeNotifier {
  User _user = User();

  get user {
    return _user;
  }

  set user(User user) {
    this._user = user;
    notifyListeners();
  }
}

and the part of the AuthService used to fetch the profile:

Future<User> getUser() async {
  print('GETTING THE USER');
  final fbaseUser = await _auth.currentUser();
  final snapshot = await _db.collection('users')
      .document(fbaseUser.uid)
      .get();
  if (snapshot.data != null) {
    Map<dynamic, dynamic> jsres = snapshot.data;
    _user = User.fromJson(jsres);
    return _user;
  }
}

Why am I getting this error? What am I doing wrong? Can anyone help me with this, please?

Answer 1

code with problem:

if(condition)
{
  ...
  ...
  notifyListners(); // problem
}else{
  await Future....
  ...
  ...
  notifyListners();  //not getting problem here    
}

code with solution: i am not using await thats why getting the error. so use await in async function, before using notifyListners()

if(condition)
{
  ...
  ...
  await Future.delayed(Duration(milliseconds: 1)); // use await 
  notifyListners(); 
}else{
  await Future....
  ...
  ...
  notifyListners();      
}

Answer 2

When I got this message it turned out that there was a notifylisteners() call in a widget that was a listener.

I just removed the superfluous notifyListeners() call and everything worked.

Answer 3

Before

class UserProfile with ChangeNotifier {
  User _user = User();

  get user {
    return _user;
  }

  set user(User user) {
    this._user = user;
    notifyListeners();
  }
}

Add one more method:

  void Adduser(User user) {
    this._user = user;
  }

Now notifier model class:

class UserProfile with ChangeNotifier {
  User _user = User();

  get user {
    return _user;
  }

  set user(User user) {
    this._user = user;
    notifyListeners();
  }

  void Adduser(User user) {
    this._user = user;
  }
}

Call:

userProfile.Adduser(snapshot.data);

---

Problem:

///problem is here and notifylistner
userProfile.user = snapshot.data;

Whenever we call notifylistner() rebuild the widget.