..and with a single golden grain of fairy dust, as if by magic, the problem goes away, the blood pressure drops, calm returns! 😊 Thank you - very much.
This one little golden nugget of information explains the previously confusing fact that I had previously successfully defined and used a 'callbackobject' property without seeing a problem. How? Two reasons:
1) the name was not overloaded in superior classes
2) I had not made a stupid mistake with the name. I checked, and you were absolutely correct, the error did say 'mytestproperty' because this is what I had typed into the form constraints despite putting 'rhtestproperty' into the form-field code. So I typed in the wrong thing, and then couldn't see it no matter how many times I looked at it. I think this is known as 'missing the gorilla'! (Incidentally, I was able to see this after you message because when trying again I made the same typing error again!) Oh the fallability. :-|
Now that the parameters are in the correct order, the value of inplace is correctly passed through.
Oh...thank you.
R.
