handleLoadMore method

Called when loadMoreAppointments function is called from the loadMoreWidgetBuilder. Call the notifyListeners to notify the calendar for data source changes.

See also:

• SfCalendar.loadMoreWidgetBuilder, which used to set custom widget, which will be displayed when the appointment is loading on view.
• notifyListeners, to add, remove or reset the appointment and resource collection.
• Knowledge base: How to load appointments on demand

 @override
 Future<void> handleLoadMore(DateTime startDate, DateTime endDate) async {
 await Future.delayed(Duration(seconds: 5));
   List<Appointment> newColl = <Appointment>[];
   for (DateTime date = startDate;
       date.isBefore(endDate);
       date = date.add(Duration(days: 1))) {
     newColl.add(Appointment(
       startTime: date,
       endTime: date.add(Duration(hours: 2)),
       subject: 'Meeting',
       color: Colors.red,
     ));
   }

   appointments!.addAll(newColl);
   notifyListeners(CalendarDataSourceAction.add, newColl);
 }