Consolidated form validation state?

I’m trying to work out the best way to enable a submit button on a form where there are a lot of elements. Many of the input elements have validation set, and I only want to enable the button when all are valid, but I can’t see a consolidated “form valid” field anywhere. Each input has such a field, but it is very messy to go through and join them.

It feels like there should be a single “form is valid” binding - am I just being too hopeful? How do others work around this if it’s not available?