In this series blog entry I’ll show that data from an ADO.NET Data Services (the OData predecessor) can be retrieved and displayed in a sample application I created that was demonstrated across Canada in Microsoft’s EnergizeIT tour.
Silverlight 3 includes support for consuming ADO.NET Data Services which use a RESTful architecture to expose CRUD operations on data in the cloud.
OData is a Microsoft-published open protocol which builds on ADO.NET Data Services. Full OData support is not included in Silverlight 3, though a CTP add-on was made available. Silverlight 4 does include support for consuming OData.
WCF Data Services in .NET 4.0 includes the ability to publish OData-based data sets based on entity framework models, CLR objects or a custom-built publisher.
OData (and its predecessor) is typically used for publishing and consuming sets of data, but in the sample application, we published sample insurance policy, claim data and customer activities using ADO.NET Data Services, and allowed client software to query the data for a single customer as shown here…
In this case, not only was basic text data loaded into the UI, but binary image data was loaded into the application and geo-coordinates used with a Bing Maps Silverlight control to show a location.
In Silverlight 3 there are LINQ to ADO.NET Data Services classes and in Silverlight 4 (or the 3 add-on CTP) there are LINQ to OData client classes.
Code like the following allows Silverlight to easily connection to an OData service (after an earlier Add Service Reference) and query deeply into the datasets.
All such requests must be handled asynchronously in Silverlight, though inline anonymous delegates in C# (shown above) are very handy for processing the asynchronous results with inline code (though typically with more exception handling code than shown here).
Binding or imperative code (or MVVM) is then typically used to show the results in the UI.
This sample application represents a fairly basic case. Silverlight 4 + OData opens up some great possibilities and you can see more in my Dot Net Rocks TV episode on how to create an OData services in .NET 4 WCF Data Services and consume it in Silverlight 4.