I am working on a task to create relationships of a document automatically. It requires to handle some logics in the event of after saving a new/existing document.

I have thought of a way to use the user contribution webpart and add my logic on the code behind of the webpart. Unfortunately, it does not handle the native form tab in cmsdesk. Any better idea how could I work on the event of the native form tab?

Please advise. Thanks.