class Profile extends StatefulWidget {
#override
_ProfileState createState() => _ProfileState();
}
class _ProfileState extends State<Profile> {
Future<DocumentSnapshot> getData() async {
return await FirebaseFirestore.instance
.collection('user')
.doc(FirebaseAuth.instance.currentUser.uid)
.get();
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Profile'),
),
body: FutureBuilder(
future: getData(),
builder: (context, AsyncSnapshot<DocumentSnapshot> snapshot) {
if (snapshot.connectionState == ConnectionState.done) {
if (snapshot.data.data() == null)
return Center(child: Text((snapshot.data.data()).toString()));
else
return ListView.builder(
shrinkWrap: true,
itemCount: 1,
itemBuilder: (BuildContext context, int index) {
return ListTile(
title: Text(snapshot.data.data()['email']),
);
});
} else if (snapshot.connectionState == ConnectionState.none) {
return Text("No data");
} else
return CircularProgressIndicator();
},
),
);
}
}
This code is always showing 'null' . What is the reason for which snapshot.data.data() is null?
Im new to future builder and Im not understanding what could be the reason for this error.
just use snapshot.data==null or !snapshot.exists
Related
i need assistance on how i could possibly query a current logged in / signed in users data so i can display their specific data using the snippet of code below -
class AddStore extends StatelessWidget {
AddStore({Key? key}) : super(key: key);
final CollectionReference _user =
FirebaseFirestore.instance.collection("users");
#override
Widget build(BuildContext context) {
return Scaffold(
body: StreamBuilder(
stream: _user.snapshots(),
builder: (context, AsyncSnapshot<QuerySnapshot> streamSnapshot) {
if (!streamSnapshot.hasData) {
return const SizedBox(
height: 250,
child: Center(
child: CircularProgressIndicator(),
),
);
} else {
return ListView.builder(
itemCount: streamSnapshot.data!.docs.length,
itemBuilder: ((context, index) {
final DocumentSnapshot documentSnapshot =
streamSnapshot.data!.docs[index];
return Column(
children: [
Text(documentSnapshot['fullName']),
],
);
}));
}
}));
}
}
You need to add the current user id i.e FirebaseAuth.instance.currentUser!.uid while querying the data from users collection. And this results in single document so you should avoid using ListView
Change the StreamBuilder to this
StreamBuilder<DocumentSnapshot<Map<String, dynamic>>>(
stream: FirebaseFirestore.instance
.collection('users')
.doc(FirebaseAuth.instance.currentUser!.uid).snapshots(),
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']);
},
)
Currently struggling to make a ListView data retrieved from Firestore.
I am trying to get "kids name" saved under in the firestore as linked photo.
Firestore
No error message is shown up but the data is not retrieved correctly and shown blank screen...hope anyone can correct my code!
and here is my code:
class kidsNamePick extends StatefulWidget {
#override
_kidsNamePickState createState() => _kidsNamePickState();
}
class _kidsNamePickState extends State<kidsNamePick> {
List<Memo> kidsnamelist = [];
Future<void>fetchMemo()async{
final kidsnames = await FirebaseFirestore.instance.collection('useraccount').doc(FirebaseAuth.instance.currentUser!.uid)
.collection('kidsname').get();
final docs = kidsnames.docs;for (var doc in docs){
Memo fetchMemo = Memo(kidsname: doc.data()['kids name'],
);
kidsnamelist.add(fetchMemo);}
setState(() {
});}
#override
void initState(){
super.initState();
fetchMemo();
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Add/Select Kids'),
),
body: ListView.builder(
itemCount: kidsnamelist.length,
itemBuilder: (context, index){
return ListTile(
title: Text(kidsnamelist[index].kidsname),
);
},
)
);
}
}
The best way to call future method is using FutureBuilder, first change your fetchMemo to this:
Future<List<Memo>> fetchMemo() async {
try {
final kidsnames = await FirebaseFirestore.instance
.collection('useraccount')
.doc(FirebaseAuth.instance.currentUser!.uid)
.collection('kidsname')
.get();
final docs = kidsnames.docs;
return docs
.map((doc) => Memo(
kidsname: doc.data()['kids name'],
))
.toList();
} catch (e) {
return [];
}
}
then change your build method to this:
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Add/Select Kids'),
),
body: FutureBuilder<List<Memo>>(
future: fetchMemo(),
builder: (context, snapshot) {
switch (snapshot.connectionState) {
case ConnectionState.waiting:
return Text('Loading....');
default:
if (snapshot.hasError) {
return Text('Error: ${snapshot.error}');
} else {
List<Memo> data = snapshot.data ?? [];
return ListView.builder(
itemCount: data.length,
itemBuilder: (context, index) {
return ListTile(
title: Text(data[index].kidsname),
);
},
);
}
}
},
),
);
}
I have problem reading data in real time with flutter and firebase.
class _MovieInformationState extends State<MovieInformation> {
final Stream<QuerySnapshot> _moviesStream = FirebaseFirestore.instance.collection("Movies").snapshots();
#override
Widget build(BuildContext context) {
return StreamBuilder<QuerySnapshot>(
stream: _moviesStream,
builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
if (snapshot.hasError) {
return const Text('Something went wrong');
}
if (snapshot.connectionState == ConnectionState.waiting) {
return const Text("Loading");
}
return ListView(
children: snapshot.data!.docs
.map((DocumentSnapshot document) {
Map<String, dynamic> data =
document.data()! as Map<String, dynamic>;
return ListTile(
title: Text(data['name']),
subtitle: Text(data['poster']),
);
})
.toList()
.cast(),
);
},
);
}
}
I want to compound firestore datas. Which widget is useful for multiple data?
For instance, i have user datas and user post's datas. I want to show them in the same Card Widget, but their snapshots are different. How can i compound them ?
I write just like this, but it shows just 1 snapshot, i want to both futurebuilder and streambuilder snapshots:
note: i can't use user datas, in below it has final dataUser = snapshotUser.data;
but i can't use it, it gives an error
class HomePageBodyWidget extends StatelessWidget {
#override
Widget build(BuildContext context) => StreamBuilder<QuerySnapshot>(
stream: FirebaseFirestore.instance.collectionGroup('Posts').snapshots(),
builder: (context, AsyncSnapshot<QuerySnapshot> snapshot) {
if (snapshot.hasError) {
return Center(child: CircularProgressIndicator());
}
if (snapshot.connectionState == ConnectionState.waiting) {
return Center(child: CircularProgressIndicator());
}
if (!snapshot.hasData) {
return Center(child: CircularProgressIndicator());
}
return ListView(
children: snapshot.data.docs.map((DocumentSnapshot docPost) {
return FutureBuilder(
future: FirebaseFirestore.instance
.collection('Users')
.doc(docPost.reference.parent.parent.id)
.get(),
builder: (context, snapshotUser) {
if (!snapshotUser.hasData) {
return Center(child: CircularProgressIndicator());
}
return homePageCard(context, dataPost: docPost, dataUser: snapshotUser.data);
},
);
}).toList());
});
}
i solved it, like this:
class HomePageBodyWidget extends StatelessWidget {
#override
Widget build(BuildContext context) => StreamBuilder<QuerySnapshot>(
stream: FirebaseFirestore.instance.collectionGroup('Posts').snapshots(),
builder: (context, AsyncSnapshot<QuerySnapshot> snapshot) {
if (snapshot.hasError) {
return Center(child: CircularProgressIndicator());
}
if (snapshot.connectionState == ConnectionState.waiting) {
return Center(child: CircularProgressIndicator());
}
if (!snapshot.hasData) {
return Center(child: CircularProgressIndicator());
}
return ListView.builder(
itemCount: snapshot.data.docs.length,
itemBuilder: (context, index) {
final dataPost = snapshot.data.docs[index];
return FutureBuilder(
future: FirebaseFirestore.instance
.collection('Users')
.doc(dataPost.reference.parent.parent.id)
.get(),
builder: (context, snapshotUser) {
final dataUser = snapshotUser.data;
if (!snapshotUser.hasData) {
return Center(child: CircularProgressIndicator());
}
return homePageCard(context,
dataPost: dataPost, dataUser: dataUser);
},
);
});
});
}
Want to create a list view from live data from server using stream,
so create fake stream of data and then save its snapshot in a list to test result, when use that list in ListTile and run app get following error:
The following assertion was thrown building ListTile(dirty):
No Material widget found.
ListTile widgets require a Material widget ancestor.
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
home: SafeArea(
child: Center(
child: StreamBuilderPage(),
),
),
);
}
}
class StreamBuilderPage extends StatefulWidget {
#override
_StreamBuilderPageState createState() => _StreamBuilderPageState();
}
class _StreamBuilderPageState extends State<StreamBuilderPage> {
List<int> items = [];
#override
Widget build(BuildContext context) {
return StreamBuilder(
//Error number 2
stream: NumberCreator().stream,
builder: (context, snapshot) {
if (snapshot.connectionState == ConnectionState.waiting) {
return CircularProgressIndicator();
} else if (snapshot.connectionState == ConnectionState.done) {
return Text('done');
} else if (snapshot.hasError) {
return Text('Error!');
} else {
items.add(snapshot.data);
print(items); //print every second: [0] then [0,1] then [0,1,2] ...
return ListView.builder(
itemBuilder: (context, index) {
return ListTile(
title: Text(items[index].toString()),
);
},
itemCount: items.length,
);
}
},
);
}
}
class NumberCreator {
NumberCreator() {
Timer.periodic(Duration(seconds: 1), (timer) {
//add count to stream
_controller.sink.add(_count);
_count++;
});
}
var _count = 1;
final _controller = StreamController<int>();
Stream<int> get stream => _controller.stream;
dispose() {
_controller.close();
}
}
What actually cause this error?
Thanks community.
Try this
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
home: StreamBuilderPage(),
);
}
}
class StreamBuilderPage extends StatefulWidget {
#override
_StreamBuilderPageState createState() => _StreamBuilderPageState();
}
class _StreamBuilderPageState extends State<StreamBuilderPage> {
List<int> items = [];
#override
Widget build(BuildContext context) {
return Scaffold(
body: SafeArea(
child: Center(
child: StreamBuilder(
//Error number 2
stream: NumberCreator().stream,
builder: (context, snapshot) {
if (snapshot.connectionState == ConnectionState.waiting) {
return CircularProgressIndicator();
} else if (snapshot.connectionState == ConnectionState.done) {
return Text('done');
} else if (snapshot.hasError) {
return Text('Error!');
} else {
items.add(snapshot.data);
print(
items); //print every second: [0] then [0,1] then [0,1,2] ...
return ListView.builder(
itemBuilder: (context, index) {
return ListTile(
title: Text(items[index].toString()),
);
},
itemCount: items.length,
);
}
},
),
),
),
);
}
}
class NumberCreator {
NumberCreator() {
Timer.periodic(Duration(seconds: 1), (timer) {
//add count to stream
_controller.sink.add(_count);
_count++;
});
}
var _count = 1;
final _controller = StreamController<int>();
Stream<int> get stream => _controller.stream;
dispose() {
_controller.close();
}
}
I think you have to embed ListTile in a Material specific widget such as scaffold. I had a similar issue a few days ago and somewhere the message tells you which widgets may be wrapped around to prevent this error
StreamBuilder(
//Error number 2
stream: FunctionWhichReturnSomething().stream,
builder: (context, snapshot) {
if (snapshot.connectionState == ConnectionState.waiting) {
return CircularProgressIndicator();
} else if (snapshot.connectionState == ConnectionState.done) {
return Text('done');
} else if (snapshot.hasError) {
return Text('Error!');
} else {
items.add(snapshot.data);
print(
items); //print every second: [0] then [0,1] then [0,1,2] ...
return ListView.builder(
itemBuilder: (context, index) {
return ListTile(
title: Text(items[index].toString()),
);
},
itemCount: items.length,
);
}
},
)