I am really impressed with this set of programming tools. However, I am a bit frustrated with the documentation. I have read the FAQ, Users Guide and have browsed the forum, looking for tutorials. I have looked at the sample applications trying to figure out how to do what I want. So far, I guess it just hasn’t really gelled.
You need to use GoDiagram Win, not GoDiagram Express, if you want to build your own kinds of nodes like that. That’s why the Express documentation doesn’t show you how to do that.
More research has turned up a possible solution: