RIA Services and Validation

Earlier today, my SilverlightTV recording on RIA Services and Validation went online. I used validation as a feature area to focus on this first recording on RIA Services, because I think it illustrates both the RIA Services value proposition and key elements of the vision around the project in a very direct manner. Specifically:

• Focus on end-to-end solutions for data scenarios. It is not sufficient to just address querying data or submitting some changes, but about providing the infrastructure for managing data, editing with validation, tracking errors raised on client and/or server, rolling back changes, and more.


• The server project and client project are logical halves of the same application. It would be great to preserve and propagate developer intent, and semantics from the database to the middle tier to the client, and share code across tiers where possible. In other words leverage intent and rules as close to the end-user, while enforcing them at each tier. Automatically.


• Provide out-of-box solutions to common scenarios. The Entity class on the client provides a pretty complete implementation of working with data on the client. It provides identity management, change tracking, change notification, transacted editing and rollback capabilities, as well as tracking and surfacing validation and concurrency conflict errors. In particular, in the context of this post, Entity provides an implementation of infrastructure interfaces such as INotifyDataErrorInfo introduced in Silverlight 4, so you don't have to roll your own.

In my demo for SilverlightTV, I used a product catalog and product editing scenario (my favorite scenario if you ask folks on the team). However for MIX10, I used a Book Club scenario, which I think is quite a bit more interesting (with the potential to become my new favorite scenario).

Check out the video. And then come back to read further. My MIX10 summary post lists everything else going on in the Book Club sample (along with a link to all of the sample code), but the rest of the post focuses on the validation aspects.

Update 3/26/10: For those looking for a copy of the app demo'd on the SilverlightTV show, you can download the Store sample.

[Full post continued here...]