Wednesday, August 26, 2009

LINQ to Bing, Silverlight and .NET RIA Services

by via Nikhil Kothari's Weblog on 8/26/2009 6:20:20 PM

In my last post, I described BLinq, or LINQ to Bing, an API that allows you use LINQ to access the Bing search results (ok, so perhaps BLinq was not the best of names, given prior art on that name ... but anyway). I also alluded to .NET RIA Services integration, which I'll cover in this installment. In fact, IQueryable and the LINQ pattern lie at the very heart of .NET RIA Services, in allowing developers to access data in a consistent manner not just on client or server but across client and server, and enabling code to compose queries naturally. If you haven't read the intro post, please take the few minutes to check out the LINQ snippets to get a general sense before continuing on.

You might use Bing in your rich internet application in one of two ways: have your client make requests to Bing by proxying through your server, or make requests directly from the client, using a cross-domain networking API, such as the one provided by Silverlight. I'll show both approaches in this post.

Here is a screenshot of the Silverlight application using .NET RIA Services. It is pretty straightforward and minimalistic. It has a search TextBox, and a couple of panels to display matching pages and images, along with some paging UI. Behind the scenes are a couple of DomainDataSource controls to perform the data loading one page at a time.

I have two apps with the same user interface demonstrating the two different approaches. The first uses RIA Services on both server and client. The second will use RIA Services only on the client, and will demonstrate how you can in fact use the client programming model and framework against a custom or very different back-end service (in this case, Bing).