The onRectangleSelecting event is a real-time event that is fired by the JavaScript Scheduler when the rectangle selection is in progress.
DayPilot.Scheduler.onRectangleSelecting(args);args.events - an array of events that overlap with the rectangle
args.start - start time of the rectangle selection (DayPilot.Date object)
args.end - end time of the rectangle selection (DayPilot.Date object)
args.resources - an array of resources that overlap with the rectangle selection (array of IDs)
args.visible - a flag that lets you hide the rectangle highlight (boolean)