How to retrieve real time changes from Firestore document in Flutter? - flutter

Question

I'm trying to work with realtime changes in firebase.
I found this doc but it only applies to collections. I'd like to grab data from a single document.
The sample code is below, how should I change it in order to refer to a document?
class UserInformation extends StatefulWidget {
#override
_UserInformationState createState() => _UserInformationState();
}
class _UserInformationState extends State<UserInformation> {
final Stream<QuerySnapshot> _usersStream =
FirebaseFirestore.instance.collection('users').snapshots();
#override
Widget build(BuildContext context) {
return StreamBuilder<QuerySnapshot>(
stream: _usersStream,
builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
if (snapshot.hasError) {
return const Text('Something went wrong');
}
if (snapshot.connectionState == ConnectionState.waiting) {
return const Text("Loading");
}
return ListView(
children: snapshot.data!.docs
.map((DocumentSnapshot document) {
Map<String, dynamic> data =
document.data()! as Map<String, dynamic>;
return ListTile(
title: Text(data['full_name']),
subtitle: Text(data['company']),
);
})
.toList()
.cast(),
);
},
);
}
}

Answer 1

Maybe I found a solution, it seems working
StreamBuilder<DocumentSnapshot<Map<String, dynamic>>>(
stream: FirebaseFirestore.instance.collection('Users').doc(documentId).snapshots(),
builder: (BuildContext context, AsyncSnapshot<DocumentSnapshot<Map<String, dynamic>>> snapshot) {
if (snapshot.hasError) {
return const Text('Something went wrong');
}
if (snapshot.connectionState == ConnectionState.waiting) {
return const Text("Loading");
}
Map<String, dynamic> data = snapshot.data!.data() as Map<String, dynamic>;
return Text(" Full name ${data['Full name']} ");
}
)