Validate Subscription

Summary

Is there a way to add validations to 'Validate' or 'Activate' action button

Content

We have a requirement that a Subscription Contract needs to always have an 'attachment' - which is a confirmation email from the customer. 

We want to add some this validations to the 'Validate' and 'Activate' button, besides the standard ones. Is there an way to do this?

EBS Service Contracts had this flexibility. Any chance this in the road map.

 

Thanks

Mitul