FIX Null Pointer Exception

[andypower]

When you try to use the method getCalendarEventId(...) and the parent class returns null for getDesktop() the NPE is thrown.
I added a simple check to avoid to throw NPE and few loc to generate a random UUID in case of lack of the Desktop Object.

[hawkchen]

Thanks for your effort. Normally, if the desktop is null, that means the component is not attached on a page. Could you provide a reproducible example about how do you encounter NPE?

[andypower]

Yes, you are right, the page must not be null if the component is attached but in my case I had a lot of NPE using the popup calendar component.
Attached there are the files that I use. The issue happens after pressing the "Salva" (save) button on the popupCalendario.zul component. After it closes the pup-up the NPE appears but not everytime I use it. I was not capable to determine the difference between executions. Maybe a race condition issue?
I use a viewmodel instead that a controller and I use the queue to manage the events. The only way I found to avoid NPEs was to add the if clause on your code
classes.zip