CTP2 of ADO.NET Data Services v1.5 release is now available for download here. ADO.NET Data Services v1.5 CTP2 is the second tech preview release of the next version of ADO.NET Data Services.  This release (v1.5) will target the .NET Framework 3.5 SP1 & Silverlight 3 platforms and provide new client and server side features for data service developers.  In addition, the features included in this release (v1.5) will be part of the .NET Framework 4 release.

This release includes updates to the features that were in the CTP1 release of ADO.NET Data Services v1.5 plus a few additional new features and a number of bug fixes. The features included in this CTP are:

· Projections: This ADO.NET Data Services URI format has been extended to express projections (i.e. you can now work with a subset of the properties of an entity).  This CTP includes both server and client library (including LINQ support) support for projections.

· Data Binding:  The data services client library for the .NET Framework 3.5 SP1 and Silverlight2 has been extended to support two-way data binding for WPF and Silverlight based applications.

· Row Count: The data services addressing scheme was extended to allow a client to obtain this type of information without having to download all the entities in a set.

· Feed Customization (aka ‘Web Friendly Feeds’):  This feature gives the ability to customize how entities are mapped into the various elements of an AtomPub feed by providing a data service author declarative control over how the data service runtime maps the properties of an entity (e.g. a Customer, Order, etc) to the elements of a feed.

The number of Atom elements which entity properties can be mapped to was extended. Each of the attributes used to customize feeds was renamed.

· Server Driven Paging (SDP): If you had a data service that exposes photos, you likely want to limit the total number of photos a single request to the service can retrieve because the total collection of photos may be very large. This feature allows a service author to set per collection limits on the total number of entities returned for each request. In addition to limiting the number of photos returned per request, the server provides the client a ‘next link’ which is simply a URI specifying how to continue retrieving the rest of the entities in the collection not returned by the first request. For those familiar with AtomPub, this feature adds support for AtomPub <link rel=’next’ …> elements to the data service runtime.

This CTP adds client library (.NET & Silverlight3) support for SDP

· Enhanced BLOB Support: This feature enhances the BLOB support provided in V1 to enable data services to stream arbitrarily large BLOBs, store binary content separate from its metadata, easily defer the loading of BLOB content when its metadata is requested, etc.

This CTP adds client library (.NET & Silverlight3) support for BLOBs.  Server support was included in CTP1

· Request Pipeline: ADO .NET team started to expose events throughout the data services server request processing pipeline. For this release they expose request level events and in future they’ll look to expose more fine grained events based on the feedback. The goal of exposing the processing pipeline is to allow services further transparency into a data service such that a service author can do things such as setting HTTP response cache headers, wrapping interceptor processing and data service request processing in a single transaction, etc.

· New ‘Data Service Provider’ Interface for Custom Provider Writers: As the data services runtime has evolved, so has the number of ways people want to plug data into the data service framework. In V1, two methods (Entity Framework and arbitrary .NET classes) were supported to enable a data service to interact with various diverse data sources. To address another class of environments and data sources, this release introduced a way to write a ‘custom’ provider for those cases when the previous two provider models don’t meet your needs.

In addition to adding a few new provider interfaces, this CTP has renamed & refactored a number of the provider interfaces introduced in this release.  Stay tuned for a follow up blog post that describes what interfaces are available and their purpose.

· Bug Fixes: This release builds on the code base shipped in CTP1 and incorporates all fixes we have made to this point.

CTP2 Frequently Asked Questions

Q1: What are the prerequisites?

A1: See the CTP2 download center page here for a list of prerequisites, supported operating systems, etc?

Q2: Does CTP2 install side-by-side with what is currently on my development machine?

A2: By in large this install is side-by-side with existing VS 2008 SP1 and .NET Fx 3.5SP1 bits; however, that was not possible in all cases so some .NET and VS files will be modified by the CTP2 installer. The files should be replaced to their original state during uninstall of this CTP. CTP2 does NOT install side-by-side with CTP1 of ADO.NET Data Services v1.5. The CTP2 installer will require you to first uninstall CTP1.

Q3: Why does the CTP2 download page include two installers?

A3: This CTP includes a ‘full’ (runtime & tools) and a ‘runtime only’ installer. The ‘full’ installer will install all required runtime assemblies as well update your VS2008 SP1 environment to work with the CTP. The ‘runtime only’ installer will install all the data services runtime assemblies as well as a command line tool (datasvcutil.exe) into the CTP2 directory. No visual studio integration will be installed by the ‘runtime only’ installer.  Having two installers is a temporary solution (for this CTP only) to allow us to get this CTP out as soon as possible. In future we will have a single installer for the release.

Q4: Does this CTP work on Windows 7?

A4: This release supports Windows 7. The CTP2 ‘full’ installer (see Q3 above) will only install the runtime components on Windows 7.  If you wish to get the ‘full’ experience on Windows 7, then you can follow steps similar  to those described by Shawn Wildermuth here (note: his post was for CTP1 of data services, but they should apply to CTP2, just be sure to look for the CTP2 directory, instead of the CTP1 directory).

(Via ADO.NET Data Services Team Blog.)

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