Hi @pgr
It is not easy to implement it, but with the other documentations, it’s a doable. I couldn’t figure out, how it will works with a Boolen field → I never got it running. But if I use VCHAR field and refere it to a selection list, it works. Now, I have to rewrite all my changes, but the result counts at the end. 
Thank you for your hint.
Cheers,
Carsten