I need a field in firebase which is their stored:
FirebaseFirestore.instance.collection("comments").doc(IdFromPost).collection(firebaseUser1.uid)
.add({"comment" : messageEditingController.text});
does anyone know how I can display the field "comment" ?
From reading the FlutterFire documentation on reading data, that should be something like:
#override
Widget build(BuildContext context) {
CollectionReference comments = FirebaseFirestore.instance.collection('comments');
return FutureBuilder<DocumentSnapshot>(
future: comments.doc(IdFromPost).get(),
builder:
(BuildContext context, AsyncSnapshot<DocumentSnapshot> snapshot) {
if (snapshot.hasError) {
return Text("Something went wrong");
}
if (snapshot.connectionState == ConnectionState.done) {
Map<String, dynamic> data = snapshot.data.data();
return Text(data['comment']);
}
return Text("loading");
},
);
}
}
Related
I am trying to implement a StreamBuilder for a specific document in a collection, however it is returning the error "null"
class _StatusBarState extends State<StatusBar> {
#override
Widget build(BuildContext context) {
return StreamBuilder(
stream: FirebaseFirestore.instance.collection('notificationsE3').doc('VlELFOHiOjCCQ3wSfpd8').snapshots(),
builder: (context, AsyncSnapshot<DocumentSnapshot> snapshot){
if (!snapshot.hasData){
return Text('loading');
}
if (!snapshot.hasError){
print(snapshot.error);
print(snapshot.toString());
return Text('something went wrong');
}
return StatusState(snapshot.data?['status']);
}
);
}
}
I am certain I have the Collection and Document ID correct, why am I getting a null error?
Terminal Output:
null
AsyncSnapshot<DocumentSnapshot<Map<String, dynamic>>>(ConnectionState.active, Instance of '_JsonDocumentSnapshot', null, null)
My QuerySnapshots are working fine in the same project.
I made Flutter project, and I want to show the name of logged in user, but the code (the yellow highlight)(https://i.stack.imgur.com/E2mU1.jpg) return null, the result be like "Name: + null" please help
I want to show the name of logged in user from the firebase
Use FutureBuilder,
Example -
class GetUserName extends StatelessWidget {
final String documentId;
GetUserName(this.documentId);
#override
Widget build(BuildContext context) {
CollectionReference users = FirebaseFirestore.instance.collection('users');
return FutureBuilder<DocumentSnapshot>(
future: users.doc(documentId).get(),
builder:
(BuildContext context, AsyncSnapshot<DocumentSnapshot> snapshot) {
if (snapshot.hasError) {
return Text("Something went wrong");
}
if (snapshot.hasData && !snapshot.data!.exists) {
return Text("Document does not exist");
}
if (snapshot.connectionState == ConnectionState.done) {
Map<String, dynamic> data = snapshot.data!.data() as Map<String, dynamic>;
return Text("Full Name: ${data['full_name']} ${data['last_name']}");
}
return Text("loading");
},
);
}
}
https://firebase.flutter.dev/docs/firestore/usage
I am trying to retrieve data from my Firestore database via a Streambuilder. The issue I have comes from an error from the following error when I add my doc(uid) into my _usersStream:
A value of type 'Stream<DocumentSnapshot<Map<String, dynamic>>>' can't be assigned to a variable of type 'Stream<QuerySnapshot<Object?>>'.
Try changing the type of the variable, or casting the right-hand type to 'Stream<QuerySnapshot<Object?>>'.
I was wondering how to how to rectify this error. Here is my code:
class _UserProfileScreenState extends State<UserProfileScreen> {
final Stream<QuerySnapshot> _usersStream = FirebaseFirestore.instance.collection('users').doc(uid).snapshots();
#override
Widget build(BuildContext context) {
return StreamBuilder<QuerySnapshot>(
stream: _usersStream,
builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
if (snapshot.hasError) {
return Text('Something went wrong');
}
if (snapshot.connectionState == ConnectionState.waiting) {
return Text("");
}
return Scaffold(
appBar: ProfileAppBar(),
body: ListView(
children: snapshot.data!.docs.map((DocumentSnapshot document) {
Map<String, dynamic> data =
document.data()! as Map<String, dynamic>;
return ListTile(
title: Text(data['username']),
subtitle: Text(data['displayName']),
);
}).toList(),
),
);
},
);
}
}
There is some issue when you define _userStream
final Stream<QuerySnapshot> _usersStream = FirebaseFirestore.instance.collection('users').doc(uid).snapshots();
_userStream is a value of type Stream<DocumentSnapshot<Map<String, dynamic>>>
_userStream should be like this.
final Stream<DocumentSnapshot<Map<String, dynamic>>> _usersStream = FirebaseFirestore.instance.collection('users').doc(uid).snapshots();
it is better to use FutureBuilder
class GetUserName extends StatelessWidget {
final String documentId;
GetUserName(this.documentId);
#override
Widget build(BuildContext context) {
CollectionReference users = FirebaseFirestore.instance.collection('users');
return FutureBuilder<DocumentSnapshot>(
future: users.doc(documentId).get(),
builder:
(BuildContext context, AsyncSnapshot<DocumentSnapshot> snapshot) {
if (snapshot.hasError) {
return Text("Something went wrong");
}
if (snapshot.hasData && !snapshot.data!.exists) {
return Text("Document does not exist");
}
if (snapshot.connectionState == ConnectionState.done) {
Map<String, dynamic> data = snapshot.data!.data() as Map<String, dynamic>;
return Text("Full Name: ${data['full_name']} ${data['last_name']}");
}
return Text("loading");
},
);
}
}
Please check this guide
I'm new into flutter and firebase integrations and I'm having some troubles to retreive all the data from the firebase collection.
I have tried this method:
getCollection() {
CollectionReference coleccion =
FirebaseFirestore.instance.collection('materias');
return Container(
child: StreamBuilder(
stream: coleccion.doc('aprobadas').snapshots(),
builder: (BuildContext context, AsyncSnapshot snapshot) {
if (snapshot.connectionState == ConnectionState.active) {
return Text(snapshot.data.data()['codigo'],
style: TextStyle(fontSize: 50, color: Colors.white));
} else {
return CircularProgressIndicator();
}
},
),
);
}
Now I'm a little bit frustrated because I have tried a differents methods and doesn't work.
I really appreciate all the help.
Best regards
Data can be retrieved using the below code from firestore to flutter.
One-time Read
call the Query.get or DocumentReference.get methods
class GetUserName extends StatelessWidget {
final String documentId;
GetUserName(this.documentId);
#override
Widget build(BuildContext context) {
CollectionReference users = FirebaseFirestore.instance.collection('users');
return FutureBuilder<DocumentSnapshot>(
future: users.doc(documentId).get(),
builder:
(BuildContext context, AsyncSnapshot<DocumentSnapshot> snapshot) {
if (snapshot.hasError) {
return Text("Something went wrong");
}
if (snapshot.hasData && !snapshot.data!.exists) {
return Text("Document does not exist");
}
if (snapshot.connectionState == ConnectionState.done) {
Map<String, dynamic> data = snapshot.data!.data() as Map<String, dynamic>;
return Text("Full Name: ${data['full_name']} ${data['last_name']}");
}
return Text("loading");
},
);
}
}
Realtime changes
FlutterFire provides support for dealing with real-time changes to collections and documents. A new event is provided on the initial request, and any subsequent changes to collection/document whenever a change occurs (modification, deleted or added).
Both the CollectionReference & DocumentReference provide a snapshots() method which returns a Stream:
Stream collectionStream = FirebaseFirestore.instance.collection('users').snapshots();
Stream documentStream = FirebaseFirestore.instance.collection('users').doc('ABC123').snapshots();
Please refer official documentation here
You can use a StreamBuilder. That will be easy to understand.
StreamBuilder(
stream: FirebaseFirestore.instance.collection("collection").snapshot,
builder: (BuildContext context,snapshot) {
if(snapshot.hasdata!=true) {
return CircularProgressIndicator();
} else {
return ListView.builder(
itemcount:snapshot.data.docs.length,
builder(context,index) {
return Text(snapshot.data.docs[index].data()["filedname"]);
}
}
)
I am building a Flutter application and I am having trouble understanding how to implement Firestore. Out of the tutorials I have seen, I only see how to create a snapshot of an entire collection, however in my case, my collection is users, so I only need to snapshot the document of a particular user. There doesn't appear to be documentation on the Firebase docs on how to do this nor is there much documentation on the FlutterFire GitHub page. Please help!
This is the Widget I'm trying to build with StreamBuilder.
#override
Widget build(BuildContext context) {
return new StreamBuilder(
stream: Firestore.instance.collection('users').document(userId).snapshots(),
builder: (context, snapshot) {
return new ListView.builder(
itemCount: //what do I put here?,
itemBuilder: (context, index) => new Item(//And here?),
);
}
);
}
Lets say you want to create a Text with the name parameter from your document
Widget build(BuildContext context) {
String userId = "skdjfkasjdkfja";
return StreamBuilder(
stream: Firestore.instance.collection('users').document(userId).snapshots(),
builder: (context, AsyncSnapshot<DocumentSnapshot> snapshot) {
if (!snapshot.hasData) {
return Text("Loading");
}
var userDocument = snapshot.data;
return Text(userDocument["name"]);
}
);
}
This is just one instance. Creating a StreamBuilder on the document will rebuild itself every time the document itself is changed. You can try this code, and then go to your console and change the "name" value. Your app will automatically reflect the changes.
Instead of just one Text, you could build entire tree that uses data from your stream.
If you want to get just at the moment value of the document, you can do so by resolving the Future of get() method on document reference.
var document = await Firestore.instance.collection('users').document(userId).get(),
Each element should be casted to have a reference later in the code.
return new StreamBuilder<DocumentSnapshot>(
stream: Firestore.instance.collection('users').document(userId).snapshots(), //returns a Stream<DocumentSnapshot>
builder: (BuildContext context, AsyncSnapshot<DocumentSnapshot> snapshot) {
if (!snapshot.hasData) {
return new Text("Loading");
}
var userDocument = snapshot.data;
return new Text(userDocument["name"]);
}
);
}
Update 2023 with null safety
class _UserInformationState extends State<UserInformation> {
final _usersStream = FirebaseFirestore.instance
.collection('users')
.doc(FirebaseAuth.instance.currentUser!.uid) // 👈 Your document id change accordingly
.snapshots();
#override
Widget build(BuildContext context) {
return Scaffold(
body: Center(
child: StreamBuilder<DocumentSnapshot<Map<String, dynamic>>>(
stream: _usersStream,
builder:
(BuildContext context, AsyncSnapshot<DocumentSnapshot> 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(data['fullName']);
},
),
),
);
}
}