That's very frustrating, because that leads to bad design.
Every tab in the tabcontrol has it's own diagram instance. So there are multiple diagrams in my application. At the moment I have a RadDiagram reference in my tab view model.
That's what I want to remove, because having a reference to a user interface element in a view model isn't very nice as you know.
I know about the serialization process of graph source objects you mentioned, but I would like to have a solution where I don't need to have a reference to a diagram instance in code behind.
I understand what you mentioned in your last section but it doesn't satisfies my needs.
In my understanding that's not what MVVM was made for...
Are there no other possibilities to get this done?