The OnClientAppointmentDeleting client-side event is called before an appointment is deleted.
Two parameters are passed to the event handler:
sender is the scheduler client object.
eventArgs has the following methods:
get_appointment() returns the appointment instance.
get_editingRecurringSeries() returns True if the user is tryingto delete a series to which the appointment belongs, False if the user is trying to delete a single occurrenceof an appointment.
set_cancel() lets you permit or block the deletion of the appointment.Calling set_cancel(true) aborts the deletion, while set_cancel(false) allows thescheduler to proceed with deleting the appointment.
This example stops the deletion if the user is about to delete an appointment's series: