Flutter sort data Firestore with Streambuilder - flutter

Question

My goal: When the user presses the "List" button inside "_mainListItem" I want the listview to get sorted by orderBy. Aswell as updated on screen
import 'package:flutter/material.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
class mainlist extends StatefulWidget {
#override
_mainlistpage createState() => _mainlistpage();
}
class _mainlistpage extends State<mainlist> {
Widget homePage() {
return StreamBuilder(
stream: Firestore.instance.collection("Test").snapshots(),
builder: (context, snapshot) {
if (!snapshot.hasData) return Text("Loading");
return ListView.builder(
itemCount: snapshot.data.documents.length,
itemBuilder: (context, index) =>
_mainListItem(context, snapshot.data.documents[index]));
},
);
}
Widget _mainListItem(BuildContext context, DocumentSnapshot document) {
return Card(
color: Colors.white,
child: InkWell(
onTap: () {
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => profile(context, document)));
},
child: Container(
width: double.infinity,
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
Container(
decoration: BoxDecoration(
border: Border(bottom: BorderSide(color: Colors.black12))),
child: Row(
children: [
Expanded(
child: Row(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Column(
children: <Widget>[
Stack(
alignment: Alignment.topRight,
children: <Widget>[
Padding(
padding: const EdgeInsets.only(right: 5),
child: ClipRRect(
borderRadius:
BorderRadius.circular(0.0),
child: FittedBox(
child: Image.asset(
"assets/Profile Picture.png",
fit: BoxFit.fill,
)),
),
),
Padding(
padding: const EdgeInsets.only(
top: 7, right: 4),
child: Text(
'Test',
style: TextStyle(fontSize: 12),
),
),
]),
Row()
],
),
Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Row(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Text(
document['name'],
),
// Text("2km"),
],
),
],
),
],
),
),
],
),
),
Column(
children: <Widget>[
Padding(
padding: const EdgeInsets.only(top: 5, bottom: 5),
child: Row(
children: <Widget>[
Padding(
padding: const EdgeInsets.only(left: 10, right: 7),
child: Container(
child: Material(
borderRadius: BorderRadius.circular(5),
shadowColor: Colors.black,
elevation: 1,
child: SizedBox(
height: 28,
width: 68,
child: IconButton(
padding: EdgeInsets.only(bottom: 10),
**icon: Icon(Icons.list),
disabledColor: Colors.blue,
iconSize: 25,**
)),
),
),
),
],
),
)
],
)
],
),
),
),
);
}
#override
Widget build(BuildContext context) {
// TODO: implement build
return new Scaffold(
backgroundColor: Colors.grey,
appBar: AppBar(
backgroundColor: Colors.grey,
leading: IconButton(
icon: Icon(Icons.arrow_back_ios),
color: Colors.red,
),
title: Text("Test"),
centerTitle: true,
actions: <Widget>[
IconButton(
icon: Icon(Icons.menu),
iconSize: 30,
color: Colors.white,
)
],
),
body: homePage(),
);
}
}
I have tried
- adding the streambuilder function into the ontapped: on the List button
- have read and watched every video there is and still can't find the solution
note: the app looks weird because I deleted unnecessary information

Answer 1

You can sort the list items before the snapshot method like:
.orderBy('sortField', descending: true).snapshot()
I hope this works for you.

Answer 2

Try mapping the values to a List<CustomObject> and using the list of objects in your list view.

Answer 3

i suggest you use state to determine the field how your list will be sorted by.
this is what i'd do to achieve this (continuing from the same code):
...
class _mainlistpage extends State<mainlist> {
String _orderBy = 'defaultSort'; //? HERE YOU PUT WHAT YOUR SORTING FIELD NAME IS
bool _isDescending = true; //? THIS IS WHAT WILL SET THE ORDER SORTING
Widget homePage() {
return StreamBuilder(
stream: Firestore.instance
.collection("Test")
.orderBy(_orderBy, descending: _isDescending) //? PUT THE ORDERBY QUERY HERE
.snapshots(),
builder: (context, snapshot) {
if (!snapshot.hasData) return Text("Loading");
return ListView.builder(
itemCount: snapshot.data.documents.length,
itemBuilder: (context, index) =>
_mainListItem(context, snapshot.data.documents[index]));
},
);
}
...
somewhere in the class, put the button or dropdown and use setState(...) to set the
states of the new variables.
NOTE: you might have to create 'indexes' in firestore. you will get errors when a new
index is required.