firebaseApi class error

[pretech86]

in FirebaseApi class when i write in getusers function
.snapshots().transform(Utils.transformer(User.fromJson(json)));

i got the following

The argument type 'StreamTransformer<dynamic, dynamic>' can't be assigned to the parameter type 'StreamTransformer<QuerySnapshot<Map<String, dynamic>>, List>

[Pranavmaid]

hey have you solved this error

[hanishk]

@Pranavmaid U can solve by lower the version of plugin cloud_firestore: ^1.0.7 or read migration changes from official docs:
https://firebase.flutter.dev/docs/firestore/2.0.0_migration

[invertedpistol]

Solved it by casting and reducing the cloud_firestore version.
".transform(Utils.transformer(Message.fromJson) as StreamTransformer<QuerySnapshot, List>);"
Hope it helps anyone coming here.

[FlutterCrypto]

@pretech86, @Pranavmaid, @hanishk and @invertedpistol:

The Firestone migration documents were not very helpful to me but with a little help of "Dr. Google" I found someone who had the same problem and he solved it, so the following code samples are not written by me.

I used these dependencies:

firebase_core: ^1.10.0
cloud_firestore: ^3.1.0

The error will not only occur when retrieving the list of users but on getting the list of messages as well, so you need to change 2 methods.

You need to change the firebase_api.dart class:

  static FirebaseFirestore _fireStoreDataBase = FirebaseFirestore.instance;
  static Stream<List<User>> getUsers() {
    return _fireStoreDataBase
        .collection('users')
        .orderBy(UserField.lastMessageTime, descending: true)
        .snapshots()
        .map((snapShot) => snapShot.docs
        .map((document) => User.fromJson(document.data()))
        .toList());
  }

  static Stream<List<Message>> getMessages(String idUser) {
    return _fireStoreDataBase.collection('chats/$idUser/messages')
        .orderBy(MessageField.createdAt, descending: true)
        .snapshots()
        .map((snapShot) => snapShot.docs
        .map((document) => Message.fromJson(document.data()))
        .toList());
  }

[errhama]

Thank u sir , it's work.