I'm new to flutter and I want to organise the elements that I get from Firestore in a list with StickyHeaders. I would like to do it with an itemBuilder and the snapshot I get from the database.
My problem is the itemBuilder builds each item separately and has to be returned, but StickyHeader needs to have all items added as children.
How can I achieve this? Just as a reference I paste my code without the StickyHeader. buildItemBubble returns a Card Widget.
StreamBuilder(
stream: buildSnapshots(_filters),
builder: (context, snapshot) {
if (!snapshot.hasData)
return Center(
child: CircularProgressIndicator(),
);
return snapshot.data.documents.length == 0
? Center(child: Text('It\s empty here...'))
: CupertinoScrollbar(
child: ListView.builder(
key: new PageStorageKey('randomkey'),
shrinkWrap: true,
padding: const EdgeInsets.all(10.0),
itemCount: snapshot.data.documents.length,
itemBuilder: (ctx, i) =>
buildItemBubble(snapshot, i),
),
);
},
)
Related
In my Flutter app, I need to display two lists that are coming from the database, but I am having trouble getting both lists to display on the same screen. I am using two FutureBuilder widgets, but the first list is displaying correctly while the second list is still loading.
Here is the code I am using:
var future1 = FutureBuilder<List<QuranTextModel>>(
future: database.getQuranText(),
builder: (context, snapshot) {
if(snapshot.hasData){
return ScrollablePositionedList.builder(
itemScrollController: scrollToIndex,
itemCount: snapshot.data!.length,
initialScrollIndex: widget.position,
itemBuilder: (context, index) {
// Build the list item widget here
});
}else{
return const Center(child: CircularProgressIndicator(),);
}
}
);
var future2 = FutureBuilder<List<UrduTextModel>>(
future: database.getUrduTranlation(),
builder: (context, snapshot) {
if(snapshot.hasData){
return ScrollablePositionedList.builder(
itemScrollController: scrollToIndex,
itemCount: snapshot.data!.length,
initialScrollIndex: widget.position,
itemBuilder: (context, index) {
// Build the list item widget here
});
}else{
return const Center(child: CircularProgressIndicator(),);
}
}
);
Column(
children: [
SizedBox(
height: 200,
child: future1,
),
SizedBox(
height: 200,
child: future2,
),
],
)
The first FutureBuilder is used to build a list of QuranTextModel objects, and the second FutureBuilder is used to build a list of UrduTextModel objects. I am using a Column widget to display both lists, with each list contained within a SizedBox widget to give it a fixed height.
The issue I am having is that only the first list is displaying correctly, while the second list is still loading. How can I get both lists to display on the same screen?
Thank you for any help you can provide!
SingleChildScrollView(
child: Column(
children: [
SizedBox(
height: 200,
child: future1),
SizedBox(height: 200,child: future2,)
],
),
),
Try this.
also you have to check your future status before populate you can check that by using
if (snap.connectionState == ConnectionState.done) { your code. you can check does snpa has data in it. }
connection state has deferent states that can help you to make your UI more interactive
Got the basic listview working with this code:
body: GetX<LokationListeCtrl>(
builder: (ctrl) => ListView.separated(
separatorBuilder: _separatorBuilder,
itemCount: ctrl.lokationListe.length,
itemBuilder: (BuildContext context, int index) {
return _lokationTile(ctrl.lokationListe.elementAt(index));
},
),
),
Ok great, so now I'll just add another list by wrapping the whole thing in a multiple child widget, but even before doing that, I'm already stuck trying to get the first list working:
body: Column(
children: [
GetX<LokationListeCtrl>(
builder: (ctrl) => ListView.separated(
separatorBuilder: _separatorBuilder,
itemCount: ctrl.lokationListe.length,
itemBuilder: (BuildContext context, int index) {
return _lokationTile(ctrl.lokationListe.elementAt(index));
},
),
),
],
),
Here using a Column, but it applies to all widgets with multiple children. The itemBuilder code is simply newer executed.
It seems like a simple and usefull thing to be able to do - the question is HOW to have multiple list in body, the "GetX way" ?
Found a solution. If we introduce a new Scaffold and wrap it in an Expanded, then GetX stops beeing an insulted little boy, and starts smiling again:
body: Column(
children: [
Expanded(
child: Scaffold(
body: MyBodyPadding(
// add space between appbar and first ListTile
child: GetX<LokationListeCtrl>(
builder: (ctrl) => ListView.separated(
separatorBuilder: _separatorBuilder,
itemCount: ctrl.lokationListe.length,
itemBuilder: (BuildContext context, int index) {
return _lokationTile(
ctrl.lokationListe.elementAt(index));
},
),
),
),
),
),
],
),
I am trying to only display certain data from a collection. In my example, I only want to show data in the list where the collection in name on firebase is equal to the name of the widget. I am unable to solve this problem
Expanded(
child: Container(
child: FutureBuilder(
future: getPosts(),
builder: (_,snapshot){
if(snapshot.data["name"]== widget.info.name){
return ListView.builder(
itemCount:
x,
itemBuilder: (_,index){
return ListTile(
title: Text(snapshot.data[index].data["name"]),
);
});
Expanded(
child: Container(
child: FutureBuilder(
future: getPosts(),
builder: (_,snapshot){
return ListView.builder(
itemCount:
snapshot.data,
itemBuilder: (_,index){
if(snapshot.data["name"]== widget.info.name){
return ListTile(
title:Text(snapshot.data[index].data["name"]),
);
}else{
return Container();
}
})}))
);
A better option will be to pass the widget name in the getPosts() function you defined and update the firebase query to do the filtering. This way it be much faster as firebase does the require indexing and will do the filtering in O(len(filtered_elements)) rather than current time complexity of O(len(all_elements)).
I followed the chat development app tutorial on the Flutter page, it's a single user app. I have now been able to create a database and store data in the database, but I now have a conundrum that I'm unable to resolve.
I'm loading the chats from the database using FutureBuilder
FutureBuilder(
future: _requestSqlDataAsync(),
builder: (context, snapshot) {
if (snapshot.data == null) {
return Container(
child: Center(
child: Text("Loading...."),
),
);
}
else {
return ListView.builder(
padding: EdgeInsets.all(8.0),
itemCount: snapshot.data.length,
itemBuilder: (BuildContext context, int index) {
return Text(snapshot.data[index].chat);
}
);
It successfully loads the data from the database but then I'm unable to pass submit new chats from TextController to the display widget in the following manner:
ListView.builder(
padding: EdgeInsets.all(8.0),
reverse: true,
itemBuilder: (_, int index) => _message[index],
itemCount: _message.length,
)
where _message is the widget that combines the data from the TextController along with animation, to display the chat.
Could anyone please guide me as to how I can load the data from the database and then pass the control for the chats to be loaded.
I'm trying to create a nested ListView, but don't know, if I can combine 2 streambuilders in a nested view, as it doesn't work. In the second StreamBuilder with the subcollection query, no data seems to be returned and I can't figure out why.
When I hardcode the document id I don't get any error, but still the query doesn't seem to return any data.
Does anybody know, how to construct a nested listview with streambuilders and Firestore?
List<Widget> buildStreamedListView() {
return [ StreamBuilder(
stream: Firestore.instance.collection('course')
.document(widget.data.documentID)
.collection('section')
.snapshots(),
builder: (context, snapshot) {
if (!snapshot.hasData) return const Text("Loading...");
return Expanded(child: ListView.builder(
itemCount: snapshot.data.documents.length,
itemBuilder: (context, index) {
//return buildListItem(context, snapshot.data.documents[index]);
return Card(
child: ExpansionTile(
title: Text(snapshot.data.documents[index]['name']),
children: <Widget>[
StreamBuilder(
stream: Firestore.instance.collection('course')
.document(widget.data.documentID)
.collection('section')
.document('4CjAZEQ416NYpu3ra3OE')
.collection('page')
.snapshots(),
builder: (context, snap) {
return ListView.builder(
shrinkWrap: true,
itemCount: snap.data.documents.length,
itemBuilder: (context, index) {
return Text('Hello you');
}
);
}
),
],
),
);
}
));
},
)];
}
The reason that I had strange errors was, that in the second builder function I didn't add the following code:
if (!snapshot.hasData) return const Text("Loading...");
Once I added it, it worked. Seems the data was just not ready yet, hence it couldn't be read and hence the error.
Be careful to also test for snap.hasData() in your nested StreamBuilder.