Conditional Fields in Dexterity Schema

Here is some related discussion

There is perhaps (some complex) way to solve this on the Python layer however I do prefer Javascript
hackery here. What we usually do in such situations is having a viewlet that injects additional markup with data-attributes (in this case the information from the parent object) into the HTML of the Plone site and then some custom JS doing the hide/no-hide magic based on the value of such a data attribute...makes sense?