Problem pulling data from GetIt to stream builder

Question

Error text:

Null check operator used on a null value The relevant error-causing widget was StreamBuilder<List>

ChangeNotifierProvider(
          create: (context) => getIt<ModelCreator>(),
          child: StreamBuilder(
              stream: getIt<ModelCreator>().chatList(),
              builder: (context, AsyncSnapshot<List<ChatModel>> snapshot) {
                var _data = snapshot.data!; <- The error is here
                return Container();
              }),
        ),

There is no problem with empty Container, that part is full.

Thats getChatList() func

  Stream<List<ChatModel>> getChatList() {
var data = _firebase
    .collection('Users')
    .doc(_fireauth.currentUser!.uid)
    .collection('Chat List')
    .orderBy('Last Message Date', descending: true);

return data.snapshots().map(
    (event) => event.docs.map((e) => ChatModel.fromSnapshot(e)).toList());

}

Thats it ChatModel

  factory ChatModel.fromSnapshot(
  QueryDocumentSnapshot<Map<String, dynamic>> doc) {
return ChatModel(
  id: doc.id,
  image: doc['Image'],
  phone: doc['Phone'],
  photo: doc['Photo'],
  username: doc['Username'],
  createdDate: doc['Created Date'],
  displayMessage: doc['Display Message'],
  lastMessageDate: doc['Last Message Date'],
);

}

score 0 · Answer 1 · answered Sep 06 '22 at 14:11

0

the snapshot data can be null. So before accessing the snapshot.data you should check

if(snapshot.hasData)

if it returns true, you can access the data without any issues

answered Sep 06 '22 at 14:11

Sujan Gainju

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I did it before but the problem is that the data is not coming. – Hüseyin APA Sep 06 '22 at 18:14
have you checked if the api is returning data? – Sujan Gainju Sep 07 '22 at 10:43
I update the question, can you check it again? – Hüseyin APA Sep 08 '22 at 11:44

Problem pulling data from GetIt to stream builder

1 Answers1