Add part

,

I have one problem: how to bind some "go.Part" to the main diagram?

I’m sorry, but I don’t know what you mean by “tie a Part to the Diagram”.
Do you mean something like what is discussed at http://gojs.net/latest/intro/legends.html ?

Valter, how to bind individual “go.Part” to the main diagram?

Are you asking about data binding in that Part? That’s supported only when the Part/Node/Group/Link is created automatically because it represents a data object in the model.

Or are you asking about data binding a property in a Part that has model data, but you want to bind to the shared Model.modelData rather than to the individual node data? That might be supported in a future version.