Get all documents from a collection from Firestore - flutter - firebase

Question

I am trying to get all the documents with their fields from firestore collection, but it's not working. I did this:
final _fireStore = FirebaseFirestore.instance;
Future<void> getData() async{
QuerySnapshot querySnapshot = await _fireStore.collection('addsaidas').get();;
final allData = querySnapshot.docs.map((doc) => doc.data()).toList();
print(allData);
}
But the screen still is empty. The code is running, but nothing appears.

Answer 1

Your code seems fine to me at first glance. For issue regarding this line
But the screen still is empty. The code is running, but nothing appears.
To display the result on screen we have to use Widgets provided by flutter.
Here’s one Example with using ListView and also printing the result in the console onPress of the FloatingActionButton :
class MyHomePage extends StatelessWidget {
MyHomePage({Key? key}) : super(key: key);
final _fireStore = FirebaseFirestore.instance;
final ref =
FirebaseFirestore.instance.collection('addsaidas').snapshots();
Future<void> getData() async {
QuerySnapshot querySnapshot =
await _fireStore.collection('addsaidas').get();
final allData = querySnapshot.docs.map((doc) => doc.data()).toList();
for (var dataMap in allData) {
if (dataMap is Map) {
// add a type check to ensure dataMap is a Map
for (var key in dataMap.keys) {
print('$key: ${dataMap[key]}'); //printing document fields using keys
}
print('----------------------');
}
}
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: const Text('My Screen')),
body: StreamBuilder<QuerySnapshot>(
stream: ref,
builder: (context, snapshot) {
if (!snapshot.hasData) {
return const Center(child: CircularProgressIndicator());
}
final documents = snapshot.data!.docs;
return ListView.builder(
itemCount: documents.length,
itemBuilder: (context, index) {
final document = documents[index];
final data = document.data() as Map<String, dynamic>;
return ListTile(
title: Text(data['nomesaida']),
subtitle: Text(data['datasaida']),
);
},
);
},
),
floatingActionButton: FloatingActionButton(
onPressed: getData,
backgroundColor: Colors.green,
child: const Icon(Icons.navigation),
),
);
}
}
You can print other fields as above mentioned.