How can I convert FutureBuilder code to StreamBuilder? - flutter

Question

I am trying to get data from Firestore and pass that data to screen using stream. I have done this using FutureBuilder, this solution works as followed, but I need to use StreamBuilder Can anyone help me find the problem?
Future<List<Business>> list(FirebaseFirestore _firesore) async {
CollectionReference _col = _firesore.collection('Buisiness');
var _result = await _col.get();
var _docs = _result.docs;
return List.generate(_docs.length, (index) {
var satir = _docs[index].data();
return Business.fromMap(satir as Map<String, dynamic>);
});
}
This Code works in FutureBuilder but not StreamBuilder
StreamBuilder<List<Business>>(
stream: _firestorelist.list(_firestore), // Error Here
builder: (context, snapshot) {
if (snapshot.hasData) {
List<Business>? data = snapshot.data;
return ListView.builder(
itemCount: data!.length,
itemBuilder: (context, index) {
var result = data[index];
return ListTile(
title: Text(result.nereden),
subtitle: Text(result.nereye),
trailing: Text(result.fiyat),
);
},
);
} else {
return CircularProgressIndicator();
}
},
)```

Answer 1

You can write your data source method as
Stream<List<Business>> list(FirebaseFirestore _firesore) {
CollectionReference _col = _firesore.collection('Buisiness');
final _snap = _col.snapshots();
return _snap.map((event) => event.docs
.map<Business>((e) => Business.fromMap(e.data() as Map<String, dynamic>))
.toList());
}

Answer 2

The current method is a One-time Read method, You can get snapshots from the specific collection.
You can change the method like this and Then use it as stream in streamBuilder:
list(FirebaseFirestore _firesore) async {
CollectionReference _col = _firesore.collection('Buisiness');
var _result = await _col.snapshots();
return _result;
}