Mvvm model ViewModel
Solution 1:
The initial thought for MVVM was indeed that the View should not know (not depend on) the Model.
In practice this meant re-implementing all those Model properties in the ViewModel (see the light-yellow box in the picture below), a lot of work. And extra painful when your Model can easily implement INPC, for example when it is generated from a database schema. Entity Framework in database-first mode lets you inject the INPC code through the T4 templates.
The consensus quickly became that it is OK to forward a ViewModel.Model
property and bind to that, just like your DM
property. See the light-blue box in the picture.
The issue is visualized well in this picture, note the large number of arrows in the top right corner. They depict the various solutions for databinding and you can use any combination of them.