Validate Event Change in Scheduler

I am trying to use the onEventChanged event to validate changes to an event. If there is a validation error I want to fail on the change (restore to original values). Can I do this?


Event occurs after moment, when changes already made, so it is too late to prevent modification.
There are two possible solution
- wrap showLightbox method of scheduler with custom code , and save properties of event before opening lightbox from
- in onEventChanged handler , restore properties to saved ones, if necessary

b) replace default editors inside lightbox form with custom ones - in such case you can control get_value method of section , and return old or new value , based on validation rules.