Flutter how to load Future list in a ListView? - list

Question

Hi how i can Load this list in a ListView or ListViebuilder?
Future<List<bool>> getBoolList() async{
List<bool> prefList = [];
var sharedPreferences = await SharedPreferences.getInstance();
Set<String> keys = sharedPreferences.getKeys();
for(int i=0; i<keys.length ; i++){
bool value = sharedPreferences.getBool(keys.elementAt(i));
prefList.add(value);
}
return prefList;
}
List<bool> list = await getBoolList();
how I got there
Flutter SharedPreferences how to load all saved?
Edit: my favorite.dart
import 'package:flutter/material.dart';
import 'package:shared_preferences/shared_preferences.dart';
// ignore: must_be_immutable
class Favoriten extends StatefulWidget {
#override
_FavoritenState createState() => _FavoritenState();
}
class _FavoritenState extends State<Favoriten> {
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Favorites'),
),
body: // MyList
);
}
}

Answer 1

You have to use stream builder. It observes the stream. (Best way to implement is using bloc pattern)
class Favoriten extends StatefulWidget {
#override
_FavoritenState createState() => _FavoritenState();
}
class _FavoritenState extends State<Favoriten> {
final _boolList = PublishSubject<List<bool>>();
Observable<List<bool>> get boolList => _boolList.stream;
loadList() async{
List<bool> prefList = [];
var sharedPreferences = await SharedPreferences.getInstance();
Set<String> keys = sharedPreferences.getKeys();
for(int i=0; i<keys.length ; i++){
bool value = sharedPreferences.getBool(keys.elementAt(i));
prefList.add(value);
}
_boolList.sink.add(prefList);
}
#override
Widget build(BuildContext context) {
loadList();
return StreamBuilder(
stream: boolList,
builder: (context, snapshot) {
if (snapshot.hasData) {
return root(snapshot.data);
} else {
return Container(
child: YourLoader(),// display loader
);
}
}
);
}
Widget root(List<bool> list){
return ListView.builder(
itemBuilder: (context, index) {
return Container(); // your design here
}
itemCount: list.length,
);
}
}
Note :- You have to add rxdart: ^0.22.0 plugin in your pubspec.yaml
and then import 'package:rxdart/rxdart.dart';