Fired during image export (JPEG, PNG, SVG) and direct printing. Allows you to provide alternative text for the event box (image export doesn't support HTML in event boxes).
DayPilot.Scheduler.onBeforeEventExport(args);
Basic HTML to text conversion - replaces line breaks:
dp.onBeforeEventExport = function(args) { args.text = args.e.client.html().replace("<br>", "\n"); };