Flutter - How can I get the Firestore items that contain their id in an array in another table as snapshots? - flutter

Question

How can I get Firestore items containing their id in an array in another table as snapshots in Flutter? I am attaching the code that I have that works perfectly for me doing a "get", but I can't find a way to convert this to Stream and print it on the screen with the StreamBuilder instead of with the FutureBuilder and update it with each change
Future<List<DocumentSnapshot<Map<String, dynamic>>>?> getPools() async {
List<DocumentSnapshot<Map<String, dynamic>>> pools = [];
final user = FirebaseAuth.instance.currentUser;
final DbUser? dbUser = await dbUserAPI.getDbUser(user);
if (dbUser != null) {
for (var pool in dbUser.pools) {
final result = await FirebaseFirestore.instance
.collection('pools')
.doc(pool)
.get();
pools.add(result);
}
return pools;
}
if (kDebugMode) {
print('Error al leer el usuario de FireStore');
}
return null;
}
In the dbUsersAPI.getDbUsers function I retrieve the user data from the "Users" table and then I get the value ".pools", which is an array of Strings with the ids of the items I want to retrieve.
I have tried many ways and to play with Streams but I am always getting a Future or Stream when I only want to get a Stream of the items that I am filtering.
I have tried with the where clause but it does not update the values. I think the problem is that I don't know how to manage the Future returned by the dbUsersAPI.getDbUsers function.

Answer 1

Well for displaying data using a StreamBuilder you need to fetch data in streams by generating a requests that ends with .snapshots() method instead of a .get() method.
A pretty simple scenario will be,
DbUser? dbUser;
getDbUser() async {
final user = FirebaseAuth.instance.currentUser;
final DbUser? _dbUser = await dbUserAPI.getDbUser(user);
if(_dbUser != null){
dbUser = _dbUser;
}
}
#override
void initState(){
getDbUser();
super.initState();
}
#override
void build(BuildContext context){
return ListView.builder(
itemCount: dbUser!.pools.length,
itemBuilder: (context, index){
final pool = dbUser!.pools[index];
return StreamBuilder(
stream: FirebaseFirestore.instance
.collection('pools')
.doc(pool)
.snapshots(),
builder: (context, snapshots){
return Container();
}
}
);
);
}