Distinguish between ports allowed to be empty and forgot to fill in

[TomNysWF]

Is your feature request related to a problem? Please describe.
A lot of our nodes do not require the output variables to be assigned and allow these fields to be empty, yet a red border is shown, is it possible to not show this?

As a further note, these red bars also show when monitoring a tree, which is a strange look if others look at the monitored tree.

[facontidavide]

so, technically Groot is right:

An output value with no default and left empty is illegal.

Now, the problem is that you may have a default in your C++ implementation, but not in the XML TreeNodesModel.

If you really believe that this behavior is not semantically correct, can you provide a simple example?

[TomNysWF]

In a lot of cases, we do not care about a bunch of outputs that we defined in a node, as we are interested in just one of the outputs, the nodes do not fail on these outputs not being given a variable. Maybe this is a specific use case, we have been using our nodes like that since the beginning. So there is nothing that is forcing it being illegal, which is great.

[facontidavide]

I will add an option in preference to disable this warning if you want but I consider it bad practice, for the records

[facontidavide]