Can I use IDataError and service layer validation together?
I am using IDataError for my my model. However, I need to check for a condition in my service layer. If the condition is not true I need to give the user a validation message so that user can input new values.
Is this possible? Anything I need to take care of when attempting this?
Its possible but not recommended. Validation logic should be in one place DanaAnnotation implement this very well in such a way that server and client side validation is configured together. But As I said you can separate any part of validation in any layer you want but in this case if a business requirement change you should trace the change in any layer and as a result you end up with wasting time.