WCF Data Services on dwmkerr.com

IDataServiceMetadataProvider Entities Missing in $metadata

Wed, 09 Nov 2011 15:49:00 +0000

If you are following through the example on creating custom data service providers as on this blog:

http://blogs.msdn.com/b/alexj/archive/2010/01/08/creating-a-data-service-provider-part-3-metadata.aspx

And you notice that your entities are not showing up in the $metadata file, double check that you have added this:

public class service : MyNewDataService
{
// This method is called only once to initialize service-wide policies.
public static void InitializeService(DataServiceConfiguration config)
{
config.SetEntitySetAccessRule("*", EntitySetRights.AllRead);
config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V2;
}
}

Just remember to set the entity set access rules for all entities - other they won't show up!

Composite Data Service Framework

Wed, 09 Nov 2011 11:02:00 +0000

Today I start a new project - the Composite Data Service Framework. The Composite Data Service Framework is a project that aims to obviate some of the limitations of WCF Data Services, specifically:

Allowing multiple data services to be aggregated in a single data service.
Providing more support for Service Operations (such as auto-generation of proxies client-side).
Aggregating different service types (entity framework, CLR types etc)
Complementing OData services with traditional WCF services with a single definition of proxies client-side.

The project is in its early stages and is hosted at:

http://cdsf.codeplex.com/

More updates will follow.

Data Service Exception "Unauthorised" when connecting to Sharepoint OData

Wed, 02 Nov 2011 10:28:00 +0000

If you are struggling to fetch data from a Sharepoint OData service and getting an error as below:

 [DataServiceClientException: Unauthorized]
System.Data.Services.Client.QueryResult.Execute() +436914
System.Data.Services.Client.DataServiceRequest.Execute(DataServiceContext context, QueryComponents queryComponents) +133

Then ensure you are setting the Credentials property of your Data Service Context, as below:

// Create the data context.
SharepointDataContext dc = new SharepointDataContext(new Uri("http://dksp/_vti_bin/listdata.svc"));
// Provide default credentials, without this authorisation will fail!
dc.Credentials = System.Net.CredentialCache.DefaultCredentials;
// Etc…
var accounts = from a in dc.Accounts select a;

Just another issue you may come across when using Sharepoint OData services!

The "Name attribute is invalid" when adding a Service Reference to a Sharepoint OData Service

Wed, 02 Nov 2011 10:19:00 +0000

Well this little issue took me a while to investigate, but the skinny is this:

If you are going to add a service reference to a Sharepoint OData service (e.g. http://sharepoint/_vti_bin/listdata.svc) then make sure your Sharepoint site name does NOT begin with a number - otherwise Visual Studio will fail to add the reference.

Quick and easy, but this took quite a while for me to find, hope it helps anyone in the same situation!