Handling close/exit event in Visual composer application

Hi,

Is there an option to handle the close/exit event (by clicking on close/exit button of window) in visual composer application? (Similiar to the WDDOEXIT/WDDOCLOSE methods available in Webdynpro ABAP). 

I am trying to generate a popup or message when user close/exit the application by clicking on close/exit button of window.

Thanks & Regards,

Vinod