I have a streamBuilder where the "snapshots()" change from Stream<QuerySnapshot<Map<String, dynamic>>> to AsyncSnapshot<Object?>.
This is weird because I have another app, with identical code and works fine.
The problem is, I cannot access "snapshot.data.docs" and all firestore datas.
Why is happening?
my code:
body: StreamBuilder(
//Stream<QuerySnapshot<Map<String, dynamic>>>
stream: firestore.collection('Books').orderBy('name').snapshots(),
//AsyncSnapshot<Object?>
builder: (context, snapshot ) {
if (snapshot.connectionState == ConnectionState.waiting)
return Center(child: CircularProgressIndicator());
{
final document = snapshot.data?; //error here
return ListView.builder(
itemCount: document?.length,
itemBuilder: (context, index) {
return Column(
Declare your StreamBuilder Widget response type as a dynamic, and you should use
snapshot.data.docs without any problem.
body: StreamBuilder<dynamic>(
stream: FirebaseFirestore.instance.collection('Books').orderBy('name').snapshots(),
builder: (context, snapshots) {
if(snapshots.hasData){
print(snapshots.data.docs.toString());
}});
Related
So I used Streambuilder to fetch CartItems from Firestore and it starting to flicker and it always goes to the top. Also can't scroll down, it always goes to the top, I used streambuilder in different parts of the app and it works perfectly but here it causing the problem...
Stream<QuerySnapshot<Map<String, dynamic>>> getCartStream() {
CollectionReference<Map<String, dynamic>> ref = FirebaseFirestore.instance
.collection("users")
.doc(FirebaseAuth.instance.currentUser!.uid)
.collection("cart");
Stream<QuerySnapshot<Map<String, dynamic>>> stream = ref.snapshots();
return stream;
}
StreamBuilder(
stream: getCarStream(),
builder: (BuildContext context, AsyncSnapshot snapshot) {
if (snapshot.connectionState == ConnectionState.waiting) {
return Container();
} else {
return ListView.builder(
itemCount: snapshot.data!.docs.length,
itemBuilder: (context, index) {
ProductModel productModel = ProductModel.fromMap(snapshot.data!.docs[index].data());
return CartItem(product: productModel);
},
);
}
},
)),
Rest of the code
Gif of the Problem
just remove the initState(), will work fine. if not then kindly share CARTITEM(..) class.
I am using a FutureBuilder inside a StreamBuilder that updates the UI every time a document is added to the activity collection, to get some aditional data from Firestore. The problem is that the FutureBuilder returns a SizedBox widget while the ConnectionState is waiting causing the all the cards to dissapear for a second. I would like to avoid this flickering since it causes a bad ui experience for users.
Is there a way to query the required user data in the activity stream so it all returns at once that way I can remove the FutureBuilder?
If not ... what would be a solution for this?
activityStream() {
return FirebaseFirestore.instance
.collection('activity')
.orderBy('timestamp', descending: true)
.limit(55)
.snapshots();
}
if (snapshot.connectionState == ConnectionState.waiting) {
return const SizedBox(
height: 65.0,
);
}
StreamBuilder<QuerySnapshot>(
stream: activityStream(),
builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
if (snapshot.hasError) {
return Text('Error: ${snapshot.error}');
}
switch (snapshot.connectionState) {
case ConnectionState.waiting:
return const Center(child: CircularProgressIndicator());
default:
final activityContent = snapshot.data?.docs
.map((data) => ActivityModel.fromFirestore(data))
.toList();
return Scrollbar(
controller: widget.scrollController,
child: ListView.builder(
shrinkWrap: true,
controller: widget.scrollController,
itemCount: activityContent!.length,
itemBuilder: (context, i) {
return FutureBuilder(
future: FirebaseFirestore.instance
.collection('users')
.where('uid', whereIn: activityContent[i].players)
.get(),
builder: (BuildContext context,
AsyncSnapshot<QuerySnapshot> snapshot) {
if (snapshot.connectionState == ConnectionState.waiting) {
return const SizedBox(
height: 65.0,
);
}
final users = snapshot.data!.docs.map((e) {
return UserModel.fromFirestore(e);
}).toList();
return MyWidget(
users: users,
);
},
);
},
),
);
}
},
);
I need to wait my function to be done in a ListView because of a Firestore request. I tried using Future.wait() but it does not work.
FutureBuilder<QuerySnapshot>(
future: FirebaseFirestore.instance
.collection('Statements')
.where('userID',isEqualTo: context.watch<User>().uid)
.get(),
builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot){
if (snapshot.hasError) {return Text("Erreur");}
if (snapshot.connectionState == ConnectionState.waiting) {
return Text("Loading");}
return Expanded(
child:ListView.builder(
itemCount: snapshot.data.docs.length,
itemBuilder: (context, index) {
DocumentSnapshot document = snapshot.data.docs[index];
Future.wait([getStatementData(document)]);
return StatementCard(statement:selectedStatement,
accommodation : relatedAccommodation,
owner : relatedOwner);
},
)
Here is the function called :
Future getStatementData(document) async {
selectedStatement = Statement.fromFirebase(document);
document.data()["accommodation"].get().then((value) {
relatedAccommodation = Accommodation.fromFirebase(value);});
await FirebaseFirestore.instance
.collection('Owners')
.doc(document["ownerList"][0])
.get().then((value) {
print(value.data());
relatedOwner = Owner.fromFirebase(value);
});
}
Should I use another future builder ?
You should do it like this by returning another Future Builder inside :
ListView.builder(
itemCount: snapshot.data.docs.length,
itemBuilder: (context, index) {
DocumentSnapshot document = snapshot.data.docs[index];
return FutureBuilder(
future: getStatementData(document) ,
builder: (context, snapshot) {
return snapshot.connectionState == ConnectionState.done
? StatementCard(statement:selectedStatement,
accommodation : relatedAccommodation,
owner : relatedOwner);
: Container();
);
},
)
I think you just missed a simple thing, FutureBuilder also has a connectionstate.done state which you can access. This waits until your future function is Done.
return FutureBuilder(
future: yourFunction,
builder: (context, snapshot) {
switch (snapshot.connectionState) {
case ConnectionState.none:
return Center(child: Text('No status',);
break;
case ConnectionState.waiting:
return Center(child: CircularProgressIndicator());
break;
case ConnectionState.done:
return Text('Im done!') // Your listviewbuilder comes here
break;
default:
}
},
),
doc: https://api.flutter.dev/flutter/widgets/FutureBuilder-class.html
example FutureBuilder with ListViewBuilder: https://medium.com/nonstopio/flutter-future-builder-with-list-view-builder-d7212314e8c9
[...]connectionState.done = [future] is not null, and has completed. If the future completed successfully, the [AsyncSnapshot.data] will be set to the value to which the future completed. If it completed with an error, [AsyncSnapshot.hasError] will be true and [AsyncSnapshot.error] will be set to the error object.[...]
I'm trying to build an app in flutter and I have come up against this problem which I can't seem to find any existing answers. How do I get only the current users posts to show? My posts collection has a user id field which I want to compare with the current user and display only the post where the userId and currentUser are the same.
return FutureBuilder(
future: FirebaseAuth.instance.currentUser(),
builder: (ctx, futureSnapshot) {
if (futureSnapshot.connectionState == ConnectionState.waiting) {
Center(
child: CircularProgressIndicator(),
);
}
return StreamBuilder(
stream: Firestore.instance.collection('posts').snapshots(),
builder: (context, streamSnapshot) {
if (streamSnapshot.connectionState == ConnectionState.waiting) {
Center(
child: CircularProgressIndicator(),
);
}
final documents = streamSnapshot.data.documents;
return ListView.builder(
itemCount: documents.length,
itemBuilder: (ctx, index) => PostItem(
documents[index]['title'],
documents[index]['imageUrl'],
documents[index]['location']['address'],
));
});
});
here is my post collection structure
You're currently getting all posts with:
Firestore.instance.collection('posts').snapshots()
If you only want posts for the current user, that'd be something like:
var uid = (await FirebaseAuth.instance.currentUser()).uid;
Firestore.instance.collection('posts').where('uid', isEqualTo: uid).snapshots()
The first line determines the UID of the current user, and then the second line uses that to request only documents whose uid field matches the value.
I just realised I hadn't but my future into a variable for the streambuilder where clause !! I was trying to use the original fireauth currentuser!
return FutureBuilder(
future: FirebaseAuth.instance.currentUser(),
builder: (ctx, futureSnapshot) {
if (futureSnapshot.connectionState == ConnectionState.waiting) {
Center(
child: CircularProgressIndicator(),
);
}
**final String currentUser** = futureSnapshot.data.uid;
return StreamBuilder(
stream: Firestore.instance
.collection('posts')
.where('userId', isEqualTo: **currentUser**)
.snapshots(),
builder: (context, streamSnapshot) {
if (streamSnapshot.connectionState == ConnectionState.waiting) {
Center(
child: CircularProgressIndicator(),
);
}
final documents = streamSnapshot.data.documents;
return ListView.builder(
itemCount: documents.length,
itemBuilder: (ctx, index) => PostItem(
documents[index]['userId'],
documents[index]['title'],
documents[index]['imageUrl'],
documents[index]['location']['address'],
));
});
});
```
I have a flutter app where a list is generated with ListView.Builder, and where the itemCount is the number of documents in a firestore collection. This works fine until a new document is added. When that happens I get the error (17 and 18 are just examples).
Invalid value: Not in range 0..17, inclusive: 18
I assume I would need to update the state when a new document is created, but I have no idea how i can call setState when that happens
Here is the relevant part of the code:
child: StreamBuilder(
stream: Firestore.instance.collection('contact').orderBy(sortby, descending: decending).snapshots(),
builder: (context, snapshot) {
if (!snapshot.hasData) return Container();
return ListView.builder(
itemCount: snapshot.data.documents.length,
itemBuilder: (context, index) =>
_personer(context, snapshot.data.documents[index], index),
);
},
),
use setState?
StreamBuilder(builder: (context, snapshot) {
return snapshot.hasData == null ? Container() : _getListView(snapshot);
} , )
_getListView(snapshot) {
setState(() {
return ListView.builder(
itemCount: snapshot.data.documents.length,
itemBuilder: (context, index) =>
_personer(context, snapshot.data.documents[index], index),
);
});
}
StreamBuilder use QuerySnapshot so list data can change
example code :
StreamBuilder<QuerySnapshot>(
builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
if (snapshot.hasError)
return new Text('Error: ${snapshot.error}');
switch (snapshot.connectionState) {
case ConnectionState.waiting: return new Text('Loading...');
default:
return new ListView(
children: snapshot.data.documents.map((DocumentSnapshot document) {
return ;
}).toList(),
);
}
},
)