How to save event with sharedpreference in flutter - flutter

Question

Hello I try to use this timeline package.
https://github.com/softmarshmallow/flutter-timeline
It's work fine to create timeline after press button but I don't success to save events with sharedpreference. I would like to restore history of the timeline at the initState.
TimelineEventDisplay get plainEventDisplay {
return TimelineEventDisplay(
child: TimelineEventCard(
title: Text("just now"),
content: Text("someone commented on your timeline ${DateTime.now()}"),
),
indicator: TimelineDots.of(context).circleIcon);
}
List<TimelineEventDisplay> events;
Widget _buildTimeline() {
return TimelineTheme(
data: TimelineThemeData(lineColor: Colors.blueAccent),
child: Timeline(
indicatorSize: 56,
events: events,
));
}
void _addEvent() {
setState(() {
events.add(plainEventDisplay);
});
}
#override
void initState() {
events = [
plainEventDisplay,
];
}

Answer 1

Create a SharedPref class so that it would be easy for you to manage things.
import 'package:shared_preferences/shared_preferences.dart';
import 'dart:convert';
class SharedPref {
read(String key) async {
final prefs = await SharedPreferences.getInstance();
if(prefs.getString(key) == null){
return null;
}
final map = jsonDecode(prefs.getString(key));
return map;
}
save(String key, value) async {
final prefs = await SharedPreferences.getInstance();
prefs.setString(key, jsonEncode(value));
}
remove(String key) async {
final prefs = await SharedPreferences.getInstance();
prefs.remove(key);
}
}
In your Flutter widget, create initState as follows:
SharedPref _prefs = SharedPref();
final events;
#override
void initState() async {
super.initState();
events = await _prefs.read('events');
}
void _addEvent() async {
setState(() {
events.add(plainEventDisplay);
});
await _prefs.save('events', events);
}