How to Load the Appointment from Json to Calendar In Flutter?
In the Flutter Calendar, appointments can be displayed from JSON data and loaded into the calendar using loadMoreWidgetBuilder.
STEP 1: In initState(), initialize the default values.
MeetingDataSource _events = MeetingDataSource(<_Meeting>[]);
@override
void initState() {
super.initState();
}
STEP 2: Define the calendar widget with the loadMoreWidgetBuilder property.
child: SfCalendar(
initialDisplayDate: DateTime(2017, 05, 01),
view: CalendarView.month,
allowedViews: [
CalendarView.day,
CalendarView.week,
CalendarView.workWeek,
CalendarView.month,
CalendarView.timelineDay,
CalendarView.timelineWeek,
CalendarView.timelineWorkWeek,
CalendarView.timelineMonth,
CalendarView.schedule,
],
dataSource: _events,
loadMoreWidgetBuilder: loadMoreWidget,
)
Widget loadMoreWidget(
BuildContext context, LoadMoreCallback loadMoreAppointments) {
return FutureBuilder<void>(
initialData: 'loading',
future: loadMoreAppointments(),
builder: (context, snapShot) {
return Container(
alignment: Alignment.center, child: CircularProgressIndicator());
},
);
}
STEP 3: The handleLoadMore retrieves appointments from JSON data and loads them into the Flutter calendar.
class MeetingDataSource extends CalendarDataSource {
MeetingDataSource(this.source);
List<_Meeting> source;
@override
List<dynamic> get appointments => source;
@override
DateTime getStartTime(int index) {
return source[index].from;
}
@override
DateTime getEndTime(int index) {
return source[index].to;
}
@override
bool isAllDay(int index) {
return source[index].isAllDay;
}
@override
String getSubject(int index) {
return source[index].eventName;
}
@override
Color getColor(int index) {
return source[index].background;
}
@override
Future<void> handleLoadMore(DateTime startDate, DateTime endDate) async {
await Future<void>.delayed(const Duration(seconds: 1));
http.Response data = await http.get(Uri.parse(
"https://js.syncfusion.com/demos/ejservices/api/Schedule/LoadData"));
dynamic jsonData = json.decode(data.body);
final List<_Meeting> appointmentData = [];
for (dynamic data in jsonData) {
_Meeting meetingData = _Meeting(
data['Subject'],
_convertDateFromString(
data['StartTime'],
),
_convertDateFromString(data['EndTime']),
Colors.red,
data['AllDay']);
appointmentData.add(meetingData);
}
appointments.addAll(appointmentData);
notifyListeners(CalendarDataSourceAction.add, appointmentData);
}
DateTime _convertDateFromString(String date) {
return DateTime.parse(date);
}
}
|
Conclusion
I hope you enjoyed learning about how to load the appointment from json to calendar with loadMoreWidgetBuilder
You can refer to our Flutter Calender feature tour page to know about its other groundbreaking feature representations. You can also explore our Flutter Calendar documentation to understand how to create and manipulate data.
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