How to use ListString in groupBy ? with flutter - flutter

Question

Hello I try to display a list of data grouped by date.
First I load all key/value saved with sharedpreference
after I use regex to match for each date the data key and data value
after I use List to add all date/data/value like that :
List<String> MylistString=[{"release_date":"2020-10-30","note3":"2222222"}, {"release_date":"2020-10-29","note3":"1111111"}, {"release_date":"2020-10-31","note3":"3333333"}, {"release_date":"2020-10-29","note4":"bdlbd"}]
I don't successed to use groupBy with a MyListString even after add .toString
var foo = groupBy({MylistString.toString()}, (i) => i["release_date"]);
But If I create a static String with the same data it work
Here is complet code who display a list of key value for each date, I search to group this data by date:
import 'package:flutter/material.dart';
import 'package:flutter_timeline/flutter_timeline.dart';
import 'package:flutter_timeline/indicator_position.dart';
import 'package:intl/date_symbol_data_local.dart';
import 'package:intl/intl.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'dart:convert';
void main() {
runApp(TimelineDemoApp());
}
class TimelineDemoApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Timeline',
debugShowCheckedModeBanner: false,
theme: ThemeData(
primarySwatch: Colors.blue,
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: PlainTimelineDemoScreen(),
);
}
}
class PlainTimelineDemoScreen extends StatefulWidget {
#override
State<StatefulWidget> createState() => _PlainTimelineDemoScreenState();
}
class _PlainTimelineDemoScreenState extends State<PlainTimelineDemoScreen> {
List<EventData> eventsData;
List<TimelineEventDisplay> events;
String Data1;
String Data2;
#override
void initState() {
super.initState();
}
List<String> stringList_note_formatted = [];
List<String> stringList_date_note1 =[] ;
String value_note1;
List<String> stringList_date_note2 =[] ;
String value_note2;
load_data() async {
//---------------------------------------------------------------------------------------------------
var input = '"2020-10-30","note1":"value1","2020-10-30","note2":"value2","2020-10-31","note1":"value3","2020-10-32","note2":"value4",';
var inputItarable = input.split(',').where((s) => s.isNotEmpty);
var i = inputItarable.iterator;
var tmp = {};
while (i.moveNext()) {
var key = i.current; i.moveNext();
var value = i.current.split(':'); (tmp[key] ??= []).add(value); } print(tmp);
var output = tmp.keys.map((key) {
var map = {}; map['"release_date"'] = key; tmp[key].forEach((e) => map[e[0]] = e[1]);
return map; }).toList();
print(output);
if (output == null) {
//no data available
eventsData = [];
} else {
//deserialize event data from json
var items = jsonDecode(output) as List;
eventsData = items.map((i) => EventData.fromJson(i)).toList();
}
//render event data
events = eventsData.map(plainEventDisplay).toList();
}
final myController2 = TextEditingController();
final myController3 = TextEditingController();
String note2;
dialog_text() async{
await showDialog<String>(
barrierDismissible: false, // user must tap button!
context: context,
builder: (BuildContext context){
return AlertDialog(
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.all(Radius.circular(20.0))),
title: Text(("Write something"),textAlign: TextAlign.center, style: TextStyle(color: Colors.black, fontWeight: FontWeight.w600, fontSize: 20)),
content:
Container(
width: MediaQuery.of(context).size.width*1,
child:
new ListView(
children: <Widget>[
Card(
color: Colors.grey[200],
child: Padding(
padding: EdgeInsets.all(8.0),
child: TextField(
controller: myController2,
maxLines:2,
decoration: InputDecoration.collapsed(hintText: "Your text"),
),
)
),
],
),
),
actions: <Widget>[
FlatButton(
onPressed: () {
Navigator.pop(context,);
},
child: Text('Validate', textAlign:TextAlign.center,style: TextStyle(
fontWeight: FontWeight.bold,
fontSize:15),
),
),
],
);
}
);
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("Timeline test"),
),
body: FutureBuilder(
future: load_data(),
builder: (context, snapshot) {
return _buildTimeline();
},
),
);
}
TimelineEventDisplay plainEventDisplay(EventData eventData) {
var formattedTime = DateFormat('dd-MM-yyyy').format(eventData.dateTime);
Widget text1() {
if (eventData.data1==null){
return Container();
}else{
return Text("note1 : ${eventData.data1}");
}
}
Widget text2() {
if (eventData.data2==null){
return Container();
}else{
return Text("note2 : ${eventData.data2}");
}
}
return TimelineEventDisplay(
anchor: IndicatorPosition.top,
indicatorOffset: Offset(0, 0),
child: TimelineEventCard(
title: Text("${formattedTime}"),
content: Column(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
new Row(
children: [
new Expanded(
child : new Card(
elevation: 3,
shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(10)),
child: new Container(
padding: const EdgeInsets.all (10.0),
child: Column(
children: [
text1(),
Padding(
padding: EdgeInsets.all(5.0),),
text2(),
],
),
),
)
)
],
)
],
)),
indicator: TimelineDots.of(context).circleIcon,
);
}
Widget _buildTimeline() {
return TimelineTheme(
data: TimelineThemeData(
lineColor: Colors.blueAccent, itemGap: 5, lineGap: 0),
child: Timeline(
anchor: IndicatorPosition.center,
indicatorSize: 56,
altOffset: Offset(10, 10),
events: events,
));
}
}
class EventData {
final DateTime dateTime;
final String data1;
final String data2;
EventData(this.dateTime, this.data1, this.data2);
EventData.fromJson(Map<String, dynamic> json)
: dateTime = DateTime.parse(json['release_date']),
data1 = json['note1'],
data2 = json['note2'];
Map<String, dynamic> toJson() => {
'release_date': dateTime.toIso8601String(),
'note1': data1,
'note2': data2,
};
}