EF Generated Classes & MVVM Project

Question

I started a project trying to respect a MVVM pattern and using Entities Framework, however I'm a bit confused regarding the different layers organisation.

Here's my current concern: EF generates POCO classes accordingly to my database structure. If I understood, those should therefore be my Models. The interactions with the Database are excluded from the basic MVVM pattern (they belong to an extra Layer - generally called Data from what I've seen -)

However those POCO classes do not implement INotifyPropertyChanged, which is from the few I've seen / understood of MVVM at the moment, a pretty much keypoint as it's what allows Binding to work.

I've come accross few links regarding this matter, but mostly different answers I read are just getting my head more and more confused.

Coming down to a more concise question: In order to complete POCO classes generated and implement INotifyPropertyChanged, what would be the ideal solution ?

• Consider POCO generated classes as part of an extra Layer, create a wrapper around it as an official Model ?
• Create a second partial class completing the POCO one ?
• Have EF generate classes while implementing this interface ? (I'd rather not for now to be honest, at least while I'm learning. Might be interesting later on though)
• I've also read about some Framework, but being still learning the basics, I'd rather struggle a bit on my own without adding tools for now, that would probably get my head even more confused rather than help at the moment.
• Something else ?

Thanks.

Answer 1

personally I'd create ViewModel objects which expose the elements of your POCO objects the UI is interested in - it seems like a fair amount of duplication but it separates your UI from the underlying business/data objects.