How to overlay classic ui page activation action



Hi all, I'm new with AEM and I'm working with 6.4.3 version, I'm trying to intercept the action when activating a page through classic UI, can someone give a clue on how to achieve this approach??

Thanks in advance.

PD: My idea is to avoid publishing a page which has a bad reference to an Asset, or validate some conditions in the content before let author activate the page for example, and show up some dialog with some message.