riverpod state 未更新

Question

(Update at the end of the post) I want to add my normal firebase auth with additional user information. In this example, name and goal calories. For that, I created this register function:

 Future<void> signUpWithEmailAndPassword(String email, String password, BuildContext context, WidgetRef ref, widget) async {
    FocusManager.instance.primaryFocus?.unfocus();
    try {
      await auth.createUserWithEmailAndPassword(email: email, password: password);
      ref.read(isUp.notifier).state = false;
      ref.read(writeItemViewModelProvider).setInitValue();
    } on FirebaseAuthException catch (e) {
    

the function setInitValue() looks like this:

class FirestoreDb extends ChangeNotifier {
   Future<void> setInitValue() async {
    await firebaseFirestore.collection('/users/${auth.currentUser!.uid}/UserInfo').doc(auth.currentUser!.uid).set({
      'name': null,
      'calories': null,
    });
  }
}

Here seems to work everything fine. Inside firestore a file gets created and my user also. Without this additional user infos my auth works also fine. So I think there is a problem with my stream of the user information. Because: I have to check if the registert user has already added information or not. I do this with a second.when function:

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final authState = ref.watch(authStateProvider);
    final watcher = ref.watch(itemsProvider);
    return authState.when(
        data: (data) {
          if (data != null) {
            return watcher.when(data: (calo) {
              if (calo.first.calories != null) {
                return const RootPage();
              } else {
                return UserInformation();
              }
            }, error: (e, trace) => ErrorScreen(e, trace),  loading: () => const LoadingScreen());

the first.when function is for the auth, here seems to be no problem, but the secons is strange. When I login first time, it says bad state. From now on, every time I register with a different account, I only get the old data from the previous account until I hot restart. After the user information, you get to this page:

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final streamData = ref.watch(itemsProvider);
    return Scaffold(
      backgroundColor: Theme.of(context).backgroundColor,
      appBar: AppBar(toolbarHeight: 0, backgroundColor: Colors.transparent),
      resizeToAvoidBottomInset: false,
      body: streamData.when(  data: (calo) {
        return Text(calo.first.calories.toString());
      }, error: (e, trace) => ErrorScreen(e, trace),  loading: () => const LoadingScreen())

    );
  }

where I can see that s old information until hot restart.

So something with my stream is not updating the state correctly. When I wrap delete the.when function and use a Streambuilder listening to the stream directly everything works.

Here is my itemsProvider:

final itemsProvider = StreamProvider<List<UsersModel>>(
      (ref) => ref.read(itemRepositoryProvider).itemsStream,
);

final itemRepositoryProvider = Provider((ref) => ReadData());

class ReadData{
  Stream<List<UsersModel>> get itemsStream {
    return firebaseFirestore.collection('/users/${auth.currentUser!.uid}/UserInfo').snapshots().map((QuerySnapshot query) {
      List<UsersModel> user = [];
      for (var usersIter in query.docs) {
        final usersModel = UsersModel.fromDocumentSnapshot(documentSnapshot: usersIter);
        user.add(usersModel);
      }
      return user;
    });
  }
}

I check with debugging and "print points" the way of the compiler and recognised the problem but have no answer why the compiler do this:

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    print("inside UserInfoBuild");
    final watcher = ref.watch(itemsProvider);
    return watcher.when(data: (userInfoData) {
      print("inside AsyncValue<List<UsersModel>>");
      if (userInfoData.first.calories != null) {
        return const RootPage();
      } else {
        return UserInformation(); [...]

declare provider:

final itemsProvider = StreamProvider<List<UsersModel>>(
      (ref) {
        print("inside stream provider");
        return ref.read(itemRepositoryProvider).itemsStream;
      },
);

so, my guess was that the print order should be:

I/flutter: inside UserInfoBuild
I/flutter: inside stream provider
I/flutter: inside AsyncValue<List<UsersModel>>

but its actually just:

I/flutter: inside UserInfoBuild
I/flutter: inside AsyncValue<List<UsersModel>>

so the compiler skips the final itemsProvider = StreamProvider. Just after a hot restart it executes the line of code

Answer 1

I think the key point is 'get' itemsStream. You have two ways to try.

// 1.

final itemsProvider = StreamProvider<List<UsersModel>>(
      (ref) => firebaseFirestore.collection('/users/${auth.currentUser!.uid}/UserInfo').snapshots().map((QuerySnapshot query) {
      List<UsersModel> user = [];
      for (var usersIter in query.docs) {
        final usersModel = UsersModel.fromDocumentSnapshot(documentSnapshot: usersIter);
        user.add(usersModel);
      }
      return user;
    }),
);

// 2. You can use StreamController to get data from firebaseFirestore.collection in ReadData class, and use a Stream variable to sync that value. Update StreamProvider to the Stream variable.