I want to create a profil page where I just display informations from the user, but I have trouble to reach the data. When I want to use my variable user it display 'Instance of Future<Map<String, dynamic>>'

If I put the 'Widget build' in async I have an error message who told me : ProfileScreen.build' ('Future Function(BuildContext)') isn't a valid override of 'StatelessWidget.build' ('Widget Function(BuildContext)').

class ProfileScreen extends StatelessWidget {
  ProfileScreen({super.key});

  @override
  Widget build(BuildContext context) {
    final user = displayUser();
    return Scaffold(
        appBar: AppBar(
          title: Text('Profile'),
        ),
        body: Align(
          alignment: Alignment.topLeft,
          child: Column(
              mainAxisAlignment: MainAxisAlignment.start,
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Align(
                  alignment: Alignment.topLeft,
                  child: Column(children: [
                    Text('Prénom :${user}\nNom :\nEmail :',
                        textWidthBasis: TextWidthBasis.longestLine),
                  ]),
                )
              ]),
        ),
        persistentFooterButtons: [
          SignOutButton(),
          BottomNavBar(),
        ]);
  }

  // Get user informations
  Future<Map<String, dynamic>> displayUser() async {
    final User? currentUser = FirebaseAuth.instance.currentUser;
    late final userUid = currentUser?.uid;
    late final ref = FirebaseDatabase.instance.ref();
    final resSnapshot = await ref.child('/utilisateur/'   userUid!).get();
    final Map<String, dynamic> user = {};

    if (resSnapshot.exists) {
      user['id'] = userUid;
      for (var value in resSnapshot.children) {
        String key = value.key as String;
        var val = value.value;
        user[key] = val;
      }
    } else {
      print('No data available.');
    }
    print(user); // This print display exactly the informations I want.
    return user;
  }
}

Thanks for your help.

CodePudding user response：

Your displayUser is async function and you can't call it inside build method, you need to use FutureBuilder like this:

@override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Profile'),
      ),
      body: FutureBuilder<Map<String, dynamic>>(
        future: displayUser(),
        builder: (context, snapshot) {
          switch (snapshot.connectionState) {
            case ConnectionState.waiting:
              return Text('Loading....');
            default:
              if (snapshot.hasError) {
                return Text('Error: ${snapshot.error}');
              } else {
                Map<String, dynamic> user = snapshot.data ?? {};

                return Align(
                  alignment: Alignment.topLeft,
                  child: Column(
                    mainAxisAlignment: MainAxisAlignment.start,
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Align(
                        alignment: Alignment.topLeft,
                        child: Column(
                          children: [
                            Text(
                              'Prénom :${user}\nNom :\nEmail :',
                              textWidthBasis: TextWidthBasis.longestLine,
                            ),
                          ],
                        ),
                      )
                    ],
                  ),
                );
              }
          }
        },
      ),
      persistentFooterButtons: [
        SignOutButton(),
        BottomNavBar(),
      ],
    );
  }

You can customize loading and error state to what you want.

CodePudding user response：

change StatelessWidget to StatefulWidget because userInteract on profileScreen, UserInteraction changes will show on firebase.

class ProfileScreen extends StatefulWidget{ ProfileScreen({super.key});

CodePudding user response：

You can load the user in the initstate and then set user using setstate

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

  @override
  State<ProfileScreen> createState() => _ProfileScreenState();
}

class _ProfileScreenState extends State<ProfileScreen> {
  Map<String, dynamic>? user;

  @override
  void initState() {
   final User? currentUser = FirebaseAuth.instance.currentUser;
    late final userUid = currentUser?.uid;
    late final ref = FirebaseDatabase.instance.ref();
    final resSnapshot = await ref.child('/utilisateur/'   userUid!).get();
    Map<String, dynamic> temp = {};

    if (resSnapshot.exists) {
      temp['id'] = userUid;
      for (var value in resSnapshot.children) {
        String key = value.key as String;
        var val = value.value;
        temp[key] = val;
      }
    } else {
      print('No data available.');
    }
    print(temp);
    setState((){
    user =temp 
});
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
          child:
              user != {} ? Text(user.toString()!) : const CircularProgressIndicator()),
    );
  }
}