To show how easily the pattern for Data Transfer Objects (DTOs) is used with RIA Services and Silverlight 3, Brad Abrams took the example app from the previous parts of the series and changed it to return DTOs rather than DAL types. Before reading this post be sure that you have checked the previous parts of the series : Part 1: Navigation Basics, Part 2: Rich Data Query, Part 3: Authentication, Part 4: SEO, Export to Excel and Out of Browser, Part 5: Astoria, Add Service Reference and WinForms.
I have gotten some great questions on my series so far… A couple of readers noted that it was not always a good idea to return DAL types back to the client. For example, in Part 2, I returned the SuperEmployee type defined by Entity Framework.
For example, if you change your backed from EF to NHibernate to their might be some effect of that in the client projection. I can also more easily control exactly how the entity looks to the client. Both the shape of the data as well as the validation, etc. To address these concerns some folks have been using pattern for Data Transfer Objects (DTOs) or some call them client objects.