This beta marks the entry of the ADO.NET Data Services Framework as well as the ADO.NET Entity Framework as part of the overall .NET/Visual Studio product and will be the final beta before the RTM of both technologies.
The remainder of this post will cover the changes and additions to the ADO.NET Data Services Framework since the last CTP in Dec 07. The
Since our last CTP in Dec 2007 along with the ASP.NET 3.5 Extensions Preview, there have been a number of changes and added features. I’ll try to summarize the changes and features below. We’ll follow up as we go with some more details on the changes and what to expect post Beta 1.
- Assembly and namespace changes. Now that we are part of the .NET Framework we have changed our assembly, namespace and API names to reflect the standard .NET naming conventions. The main assembly and namespace changes are:
- All Microsoft.Data.*.dll assemblies have been renamed to System.Data.Services.dll (server) and System.Data.Services.Client.dll (client)
- Anything in Microsoft.Web.* namespaces have moved to System.Data.Services (server types) & System.Data.Services.Client(client types)
- The assemblies are now installed to the standard location for .NET 3.5 assemblies
- API Name Changes. The main API name changes are:
- In general anything which was named WebData* has changed to DataService*
- In general anything with was named ResourceSet* or Resource* was changed to EntitySet* and Entity*
- WebDataService class changed to DataService
- IWebDataServiceConfiguration changed to IDataServiceConfiguration
- WebDataServiceContext class changed to DataServiceContext
- WebDataQuery class changed to DataServiceQuery
- ResourceActions enum changed to UpdateOperations
- Query Interceptor Changes. We changed the syntax of query interceptors to take 0 arguments and return a predicate (return type = Expression<Func<[EntityType],bool>>. An example interceptor that limits queries to all categories starting with the letter “B” now looks like:
2: public Expression<Func<ProductCategory, bool>>
4: return (pc) => pc.Name.StartsWith("B");
- Update Interceptor Changes. The ResourceActions enum changed name to UpdateOperations
- Command line tool changes. The command line tool to generate client side types for a data service (webdatagen.exe) has had a its name changed to datasvcutil.exe and its parameter list simplified. You can now find this tool in the \Windows\Microsoft.Net\Framework\V3.5 directory
- A bunch of bug fixes 🙂
- Tweaks to the ATOM payload format. We’ve made a few tweaks to the payload format based on feedback from the ATOM community. We’ve got a bit more to do here so please expect a bit of churn to the payload formats post Beta 1.
- Batching: data services now support the ability to group a set of requests into a “batch” to be sent to the server in a single HTTP request. The system supports the idea of an atomic group of operations as well as a loose group of operations without such guarantees. This release doesn’t quite have what we’re thinking in terms of a final design for this feature, but is quite representative of our thinking. An early write up of the feature is here.
- Optimistic Concurrency: Data services now support the notion of optimistic concurrency by passing concurrency token values using HTTP ETags and making conditionals requests using HTTP If-* requests. Some notes on how this works are here. We’ll also likely extend support post this Beta release to include use of the ‘*’ character in conditional requests.
- New IUpdatable interface. As was the case in the last CTP, you can create a data service over relational databases using integration with the Entity Framework or you can expose any data source as a REST service that has an IQueryable provider. In the last CTP we had defined an IUpdatable interface which could be implemented to make such data sources r/w at the service tier. We have significantly changed this interface to make it easier to use. I’ve put this “change” in the list of features as we redesigned the API based on our teams reviews and user feedback. A write up of the new interface is here.
We look forward to your feedback…
Program Manager, ADO.NET Data Service Framework