Here's the code.
Widget build(BuildContext context) {
return StreamBuilder<List<Widget>>(
stream: _getMealsViewWidgets(weekNum),
builder: (BuildContext context, AsyncSnapshot<List<Widget>> snapshot) {
if (snapshot.connectionState == ConnectionState.active) {
return Center(child: CircularProgressIndicator());
}
if (snapshot.connectionState == ConnectionState.waiting) {
return Center(child: CircularProgressIndicator());
}
if (snapshot.error != null) {
return Center(child: Text('Error occurred.'));
}
if (snapshot.connectionState == ConnectionState.done) {
return PageView(children: snapshot.data, controller: _pageController);
}
return Center(child: CircularProgressIndicator());
});
}
The PageView has fix 7 pages. I'd like to jump after a refresh to a specific page. The problem is because the PageView is a return of a StreamBuilder I can't call the pagecontroller.jumpPage method after the refresh. How can I jump to a specific page after return?
Have you tried using
WidgetsBinding.instance.addPostFrameCallback((_) {
// executes after build
})
?
Related
I have a little problem here where i have logged in with Google Auth using Firebase but everytime i tried to restart the app i expect the app will show the HomePage() without any problem, but i found that before it return, the app had like a bit seconds in LoginPage() before displaying HomePage(), is there any way to make it seamlessly
class AuthService extends StatelessWidget {
const AuthService({super.key});
#override
Widget build(BuildContext context) {
return Scaffold(
resizeToAvoidBottomInset: false,
body: StreamBuilder(
stream: FirebaseAuth.instance.authStateChanges(),
builder: (context, snapshot) {
if (snapshot.hasData) {
return HomePage();
} else {
return LoginPage();
}
},
),
);
}
}
It is happening because for snapshot to reach snapshot.hasData state it takes time, and meanwhile else part is executed which is LoginPage().
How to overcome this?
Try to wrap within snapshot.connectionState == ConnectionState.active which means once stream is connected then check the condition else return CircularProgressIndicator
Code:
StreamBuilder(
builder: (context, snapshot) {
if (snapshot.connectionState == ConnectionState.active) {
if (snapshot.hasData) {
return HomePage();
} else {
return LoginPage();
}
}
return const CircularProgressIndicator();
},
);
FutureBuilder examples in Flutter where it return a widget called CircularProgressIndicator or any other widget that acts as a placeholder during the waiting time of asynchronous call. I was wondering, what will happen to the CircularProgressIndicator widget after the FutureBuilder is done with it's async and "replaced" with another widget. Is it going to be disposed or destroyed?
Here's an example.
FutureBuilder<String>(
future: _value,
builder: (
BuildContext context,
AsyncSnapshot<String> snapshot,
) {
print(snapshot.connectionState);
if (snapshot.connectionState == ConnectionState.waiting) {
return CircularProgressIndicator();
} else if (snapshot.connectionState == ConnectionState.done) {
if (snapshot.hasError) {
return const Text('Error');
} else if (snapshot.hasData) {
return Text(snapshot.data);
} else {
return const Text('Empty data');
}
} else {
return Text('State: ${snapshot.connectionState}');
}
},
)
I just want to check the status of that placeholder widget.
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);
},
);
});
});
}
I am using Futurebuilder in flutter and having issue while closing the showDialog
Widget build(BuildContext context) {
return Scaffold(
appBar: PreferredSize(
preferredSize: Size( 50.0),
body: FutureBuilder(
future: widget.getAutoCompleteData(),
builder: (context, snapshot) {
if (snapshot.hasData) {
Navigator.of(context).pop();
} else if (snapshot.hasError) {
} else {
LoadingDialog.showLoadingDialog(context, _scaffoldKey);
}
return Center(
child: Container(child: Text("sds"),),
);
}));
}
Getting below error when screen loads
package:flutter/src/widgets/navigator.dart': Failed assertion: line 5013 pos 12: '!_debugLocked': is not true
Change this
FutureBuilder(
future: widget.getAutoCompleteData(),
builder: (context, snapshot) {
if (snapshot.hasData) {
Navigator.of(context).pop();
} else if (snapshot.hasError) { //here this is empty
} else {//remove else statement
LoadingDialog.showLoadingDialog(context, _scaffoldKey);
}
return Center(
child: Container(child: Text("sds"),),
);
})
To This
FutureBuilder<List<Post>>(
future: _dataFetcher.getPosts(),
builder: (context, snapshot) {
if (snapshot.connectionState == ConnectionState.waiting) {
return Center(
child: CircularProgressIndicator(),
);
}
if (snapshot.hasError) {
return LoadingDialog.showLoadingDialog(context, _scaffoldKey);
}
return Center(child: Text('${snapshot.data![0].title}'));
},
)
It may be caused by the re-entrant of the Navigator (you can check the answer here: Error thrown on navigator pop until : “!_debugLocked': is not true.”
)
Or, maybe you don't want to use FutureBuilder. The FutureBuilder is meant to stay in the same widget/page and show different screens when future data is not ready. If you want to push a loading dialog and close it when data is ready, you can just simply use a Future function
Future pressTheButton(context) async {
LoadingDialog.showLoadingDialog(context, _scaffoldKey); // showDialog here
final data = await getAutoCompleteData(); // await the data
Navigator.of(context).pop(); // pop the loading dialog
// return your data or error
// or rebuild the current widget with the data
}
in this below code i try to show list is empty message when snapshot.hasData is false
body: FutureBuilder(
future: Provider.of<TicketRepliesTableDao>(context).find(ticketId: _ticket.id),
builder: (context, snapshot) {
if (snapshot.connectionState == ConnectionState.done) {
if (snapshot.hasData) {
final List<TicketRepliesTableData> ticketReplies = snapshot.data;
if (ticketReplies.isNotEmpty) {
}
} else {
return _loader(message: 'list is empty');
}
} else
return CircularProgressIndicator();
},
),
but in that i have CircularProgressIndicator() always, in view,even it doesn't have any data and ticketReplies is empty
Update your builder, with this logic.
builder: (context, snapshot) {
if (snapshot.connectionState == ConnectionState.done) {
if (snapshot.hasData) {
// show your data
return Text(snapshot.data);
} else {
// show list is empty
return Text("List is empty");
}
}
// by default show loading bar
return CircularProgressIndicator();
}