Need help retrieving authorized user information Flutter Firestore - google-cloud-firestore

Question

I have implemented in my flutter application Authentication via Firebase by login and password.
I also connected to a Firestore table with user data.
I only need to show the authenticated user's data by their ID, which are assigned to the other data tables.
How to link e.g. Users id: 1 with Tasks User id:1 ?
home_page.dart
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:flutter/material.dart';
import 'package:loginui/read_data/get_user_name.dart';
class MyTaskPage extends StatefulWidget {
const MyTaskPage({Key? key}) : super(key: key);
#override
State<MyTaskPage> createState() => _MyTaskPageState();
}
class _MyTaskPageState extends State<MyTaskPage> {
final user = FirebaseAuth.instance.currentUser!;
// document IDs
List<String> docIDs = [];
// get docIDs
Future getDocId() async {
await FirebaseFirestore.instance
.collection('tasks')
.orderBy('name', descending: true)
// .where('age', isGreaterThan: 44)
.get()
.then((snapshot) => snapshot.docs.forEach((document) {
print(document.reference);
docIDs.add(document.id);
}));
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
backgroundColor: Colors.deepPurple[200],
centerTitle: true,
actions: [
GestureDetector(
onTap: () {
setState(() {
FirebaseAuth.instance.signOut();
});
},
child: Icon(Icons.logout),
),
],
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Expanded(
child: FutureBuilder(
future: getDocId(),
builder: (context, snapshot) {
return ListView.builder(
itemCount: docIDs.length,
itemBuilder: (context, index) {
return Padding(
padding: const EdgeInsets.all(8.0),
child: ListTile(
title: GetUserName(documentId: docIDs[index]),
tileColor: Colors.grey[200],
),
);
},
);
},
),
),
],
),
),
);
}
}
get_user_name.dart
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/material.dart';
class GetUserName extends StatelessWidget {
final String documentId;
GetUserName({required this.documentId});
#override
Widget build(BuildContext context) {
// get the collection
CollectionReference users = FirebaseFirestore.instance.collection('tasks');
return FutureBuilder<DocumentSnapshot>(
future: users.doc(documentId).get(),
builder: ((context, snapshot) {
if (snapshot.connectionState == ConnectionState.done) {
Map<String, dynamic> data =
snapshot.data!.data() as Map<String, dynamic>;
return Text(
'${data['name']}',
overflow: TextOverflow.ellipsis,
softWrap: true,
);
}
return Text('Loading...');
}),
);
}
}

Answer 1

final _auth = FirebaseAuth.instance;
final _firestore = FirebaseFirestore.instance;
if (_auth.currentUser != null) {
// user is signed in
final uid = _auth.currentUser!.uid;
final userData = await _firestore.collection('users').doc(uid).get();
final taskData = await _firestore.collection('tasks').doc(uid).get();
// handle the data
}