cant retreive the documents in my firebase using documents.length - firebase

Question

Hi guys im learning flutter and i have an error whenever i try to call documents in the listbuilder it gives me an error but when i tried it on a floatingactionbutton to get my texts it worked fine instead of documents i used docs it worked but for this one it doesnt work out so please help me im trying to get item counts here's my full code below
import 'package:firebase_core/firebase_core.dart';
import 'package:flutter/material.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
class ChatScreen extends StatelessWidget {
const ChatScreen({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return Scaffold(
body: StreamBuilder(
stream: FirebaseFirestore.instance
.collection('chats/Dx7QFvCELN2XFWumVWOY/messages')
.snapshots(),
builder: (ctx, streamSnapshot) {
return new ListView.builder(
itemCount: streamSnapshot.data.documents.length, //the error is in here
itemBuilder: (ctx, index) => Container(
padding: EdgeInsets.all(8),
child: Text("This Works"),
),
);
},
),
floatingActionButton:
FloatingActionButton(child: Icon(Icons.add), onPressed: () {}),
);
}
}

Answer 1

You're probably getting a null pointer exception. Initially the builder function is called before the data is returned from Firestore. You can check for that and display another Widget while there isn't any data yet:
builder: (ctx, streamSnapshot) {
if(!streamSnapshot.hasData) return CircularProgressIndicator();
return new ListView.builder(
Also, I think you might need to use docs instead of documents. The type of streamSnapshot should be AsyncSnapshot<QuerySnapshot> and according to the documentation of QuerySnapshot, there's only a docs getter.