OData .NET 8 Preview Release

Clément Habinshuti

Senior Software Engineer

We would like to announce that we are planning a new major release of OData .NET core libraries in June. Ahead of this release, we have released preview versions of the libraries to get some early feedback from the community. Specifically, the following preview releases are now available on NuGet:

It has been almost 8 years since the last major release of OData .NET core libraries. This release presents an opportunity for us to modernize our stack, address some technical debt and take better advantage of investments in .NET. To make adoption and upgrading to the new version smooth, we have opted to limit the number of breaking changes. In many cases, you should be able to upgrade to the new release by changing the version number with minimal code changes. We share a list of breaking changes below.

The most disruptive change we are making in this release is dropping support for .NET Framework. The new release will only support .NET 8 and later. We understand that there are still a lot of people using .NET Framework. For this reason, we will continue to maintain OData .NET v7 suite of libraries for the foreseeable future. We currently have no plans to drop support for OData Core 7.x. We will eventually stop adding new features after the 8.0 major release.

With this release, we will also introduce an official support policy. The support policy will document the support lifecycle for the different official OData libraries. This will state which versions are supported and for how long and this should help customers plan their migration accordingly. We will also publish a comprehensive migration guide to help you move from version 7.x to 8.0.0.

We invite you to try out these new versions and share feedback with us. Feel free to create an issue on our GitHub repository if you run into any issues with the preview release.

OData .NET 8 release schedule

April 26th, 2024: First preview release 8.0.0-preview.1
May 16th, 2024: First release candidate 8.0.0-rc1
June 20th, 2024: Official release 8.0.0

We may release additional preview versions or release candidates before the final release depending on the feedback we get. We also plan to release new versions of Microsoft.AspNetCore.OData and Microsoft.OData.ModelBuilder that take advantage of OData Core 8.x. We will communicate the dates for these releases soon.

Breaking changes in Version 8.0.0-preview.1

The sections below list the breaking changes introduced the preview release. For a full list of changes (including non-breaking changes and improvements), check the changelog.

General breaking changes

Support for .NET 8 and later only: We dropped support for .NET Framework, NET Core 3.1 and lower, .NET 7 and lower.

Breaking changes in `Microsoft.OData.Core`

Merged IJsonWriter,IJsonWriterAsync, IJsonStreamWriter, IJsonStreamWriterAsync into a single interface IJsonWriter that exposes synchronous, asynchronous and streaming APIs for writing JSON payloads
Merged IJsonReader, IJsonReaderAsync, IJsonStreamReader, IJsonStreamReaderAsync into a single interface IJsonReader that exposes synchronous, asynchronous and streaming APIs for reading JSON payloads
Changed the default value of the leaveOpen argument of the ODataBinaryStreamValue constructor from true to false. This means that by default, when the ODataBinaryStreamValue object is disposed, the underlying stream will also be closed and disposed.
JSONP support has been deprecated and will be removed in Microsoft.OData.Core 9.
The IJsonWriterFactory.CreateJsonWriter method now accepts a Stream instead of a TextWriter.
The DefaultStreamBasedJsonWriterFactory class has been renamed to ODataUtf8JsonWriterFactory.
Remove our custom IContainerBuilder interface used for dependency injection in favor of the standard Microsoft.Extensions.DependencyInjection APIs.
Introduced a new extension method called AddDefaultODataServicesto IServiceCollection for registering default OData services.
Removed the ODataSimplifiedOptions class and moved its properties to more appropriate classes (see below).
Moved EnableParsingKeyAsSegment from ODataSimplifiedOptions to ODataUriParserSettings.
Moved EnableReadingKeyAsSegment and EnableReadingODataAnnotationPrefix from ODataSimplifiedOptions to ODataMessageReaderSettings.
Moved EnableWritingKeyAsSegment, GetOmitODataPrefix and SetOmitODataPrefix from ODataSimplifiedOptions to ODataMessageWriterSettings.
Removed the ODataMessageReader.CreateODataDeltaReader and CreateODataDeltaReaderAsync methods. Use CreateODataDeltaResourceSetReader instead.
Removed the ODataMessageWriter.CreateODataDeltaWriter and CreateODataDeltaWriterAsync methods. Use CreateODataDeltaResourceSetWriterAsync instead.
Added the INavigationSourceSegment interface that exposes a NavigationSource property to provide a consistent way of retrieving the navigation source without having to perform a type cast.

Breaking changes in `Microsoft.OData.Client`

Marked the DataServiceContext.KeyComparisonGeneratesFilterQuery property as deprecated and changed the default value from false to true. This means that the LINQ query context.People.Where(p => p.Id == 10) will generate a URL filter query option like /People?$filter=Id eq 10 instead of /People(10) by default.
Removed HttpWebRequestMessage class, and consequently, support for the legacy HttpWebRequest API. All requests from the client will be made using HttpClientRequestMessage which is based on HttpRequestMessage and HttpClient.
Removed the HttpRequestTransportMode enum property from DataServiceContext. This property was used to switch between HttpClient and HttpWebRequest. Now all requests are made using HttpClient.
Added DataServiceContext.HttpClientFactory property that allows you inject your HttpClient instance by passing a custom IHttpClientFactory. This replaces the previous approach of configuring a http client using the custom IHttpClientHandlerProvider (see below).
Removed the DataServiceContext.HttpClientHandleProvider property and the IHttpClientHandlerProvider interface. These were used to provide custom HttpClient configurations. The DataServiceContext.HttpClientFactory should be used instead.
Removed the DataServiceContext.Credentials property. The DataServiceContext.HttpClientFactory should be used to provide a HttpClient instance configured with the right credentials if needed.
Removed the HttpClientRequestMessage.ReadWriteTimeout property. The HttpClientRequestMessage.Timeout can be used to set the request timeout.
Removed the DataServiceQuery<TElement>.IncludeTotalCount(bool countQuery) method. Use IncludeCount(bool countQuery) instead.
Removed the DataServiceQuery<TElement>.IncludeTotalCount() method. Use DataServiceQuery<TElement>.IncludeCount() instead.
Removed the QueryOperationResponse.TotalCount property. Use Count instead.

Breaking changes in `Microsoft.OData.Edm`

Added the EntityType property to IEdmNavigationSource interface to make it easier to retrieve the entity type from a navigation source without having to perform a type cast.

Planned changes in Version 8.0.0

This section contains a list of planned changes that are expected to make it to the official 8.0.0 release that are not available in the first preview.

Planned changes in `Microsoft.OData.Core`

Make ODataUtf8JsonWriter the default JSON writer implementation.
Use ValueTask<T> instead of Task<T> for async I/O operations where applicable.
Allow customers to include custom annotations in the payload that are not included in the include-odata-annotations preference header.
When writing the Scale attribute in XML CSDL, write variable in lowercase instead of Variable.
Change the ODataLibraryCompatibility enum into a flags enum where each bit will represent a different compatibility setting that can be used to enable some legacy serializaiton behaviour.
Remove deprecated APIs and behavior flags.

Author

Clément Habinshuti

Senior Software Engineer

13 comments

Discussion is closed. Login to edit/delete existing comments.

Damien Honeyford June 10, 2024

Is it still the intent with v8+ to use the Extensions Library for Client-based integration with Dependency Injection?

Also, will it ever be possible to use a custom name for the generated DataServiceContext class as currently we can only customise the namespace and file name?

Thanks,

Damien
Tamas Nagy May 10, 2024

It is great to see the progress with OData 8. Can we expect that the Blazor Webassembly clients will be able to use OData 8 without any restrictions as well? It would be a great experience to have a powerful and full featured data service interface available for webassembly clients…
James April 30, 2024 · Edited

Looking forward to a series of “Power of .NET” articles showing the benefits of rolling this out across M365 (Graph, SharePoint, Dynamics, etc.) – all desperately could use a consistency, functionality, and performance modernization in their OData implementations!
David Taylor April 28, 2024

@Clement The only request I would make is to make sure it is easy to do the following:
* Take a LINQ query on the client and convert it to it's OData representation. Give us lots of flexibility to send that OData representation to a server. Then allow us to reconstruct it back from the OData representation into an IQueryable on the server, where we can further manipulate, such as adding additional .Where clause, etc.

While I found I could do that with v7 following your standard patterns (using an ASP.NET Controller), I found it difficult to drop down...
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@Clement The only request I would make is to make sure it is easy to do the following:
* Take a LINQ query on the client and convert it to it’s OData representation. Give us lots of flexibility to send that OData representation to a server. Then allow us to reconstruct it back from the OData representation into an IQueryable on the server, where we can further manipulate, such as adding additional .Where clause, etc.

While I found I could do that with v7 following your standard patterns (using an ASP.NET Controller), I found it difficult to drop down to a lower level with the existing library. I spend at least a full day trying to get this to work, and almost got there before I gave up.

I suspect this might not require more work, and might just require better documentation and examples. But I would love if it was clearer how to break down to a lower level without needing to spend weeks trying to understand the internal architecture of the libraries.

All the best to your team and we look forward to the next release.

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- Clément Habinshuti Author April 29, 2024
  
  Hello David Taylor. Let me see if I understand the question: You would like an easy way to convert a LINQ query to an OData representation and from OData representation back to an IQueryable in a way that's easy to manipulate? Would you share some of the challenges you're currently facing using existing methods. One request we have received and are considering is to decouple the LINQ-to-OData query string and OData query string-to-IQueryable into standalone components that can be used with minimal dependencies on other parts of the libraries. I'd like to understand whether something along this direction would address...
  Read more
  Hello David Taylor. Let me see if I understand the question: You would like an easy way to convert a LINQ query to an OData representation and from OData representation back to an IQueryable in a way that’s easy to manipulate? Would you share some of the challenges you’re currently facing using existing methods. One request we have received and are considering is to decouple the LINQ-to-OData query string and OData query string-to-IQueryable into standalone components that can be used with minimal dependencies on other parts of the libraries. I’d like to understand whether something along this direction would address your concerns. Could you open up an issue or discussion on GitHub at https://github.com/OData/odata.net so we can flesh out all the details to understand the requirements better?
  
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  - David Taylor April 29, 2024
    
    Hi @Clément thanks for responding.
    
    Yes what you have described is exactly what I am asking for (just some decoupling, or alternatively some additional examples explaining how to achieve this with the existing coupling). So converting form LINQ query to OData; or from OData to IQueryable with full control.
    
    It was just that I spent a full day trying to work that out myself with the V7 libraries, searching for various examples, and trying to step through parts of the library. I kept hitting a context object, that then needed some other object. It was the coupling...
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    Hi @Clément thanks for responding.
    
    Yes what you have described is exactly what I am asking for (just some decoupling, or alternatively some additional examples explaining how to achieve this with the existing coupling). So converting form LINQ query to OData; or from OData to IQueryable with full control.
    
    It was just that I spent a full day trying to work that out myself with the V7 libraries, searching for various examples, and trying to step through parts of the library. I kept hitting a context object, that then needed some other object. It was the coupling that threw me off a bit and as someone who did not really understand the internals I just found it to be really difficult where my expectation was it would have been simple. On the weekend I will take another look and raise an issue, but the existing request you have cited is effectively the same as what I am asking for; or alternatively just some good documentation on how to achieve this scenario in the simplest way even with the existing coupling in place (such as with dummy context objects, etc).
    
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bytefish April 27, 2024

I like the updates to the “Microsoft.OData.Client”!

What I would like to ask though, is, what’s the OData teams opinion on generating OData clients with Kiota? The Microsoft Graph API is an OData API, and Kiota is used to generate the Microsoft Graph SDK… so it seems logical for me to also go that route.

This is not meant to discard or disrespect your work, I am just curious.
- David Taylor April 28, 2024
  
  Do be careful @bytefish as I have been through a world of pain with Graph and OData. The older (OData / Connected Services) sharepoint API had great OData support, while Graph's support is very lacking (at least viaLINQ). For example you could have a much more complex C# LINQ query translated to OData before Graph (and also today using these Microsoft.OData libraries) compared to Graph. For example try creating an items array of a few strings, then using an i => items.Contains(i) in a predicate. Graph (at least to sharepoint) will not translate that, while the...
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  Do be careful @bytefish as I have been through a world of pain with Graph and OData. The older (OData / Connected Services) sharepoint API had great OData support, while Graph’s support is very lacking (at least viaLINQ). For example you could have a much more complex C# LINQ query translated to OData before Graph (and also today using these Microsoft.OData libraries) compared to Graph. For example try creating an items array of a few strings, then using an i => items.Contains(i) in a predicate. Graph (at least to sharepoint) will not translate that, while the older APIs do.
  
  Then the most recent few versions of Graph don’t serialize certain field types in sharepoint unless you use the Kioto serializer against that specific field.
  
  Basically it can be a world of pain. Maybe think of Graph as supporting some light OData usage, and probably not via C# and LINQ.
  
  But these Microsoft.OData libraries are fantastic. You can string together all kinds of magic with these libraries. Keep up the good work.
  
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bytefish April 27, 2024 · Edited

It’s great to see the commitment to OData! I have tried to update my sample project (https://github.com/bytefish/WideWorldImporters) to the latest Previews, but the latest version of “Microsoft.AspNetCore.OData” requires a version of “Microsoft.Spatial” less than 8.0.0. So I’ll run into version conflicts, when trying to update “Microsoft.Spatial” to the 8.0.0-preview. Is it possible to also do a pre-release for “Microsoft.AspNetCore.OData” with updated dependency constraints?
- Clément Habinshuti Author April 29, 2024
  
  Hello, we’ll soon release a version of Microsoft.AspNetCore.OData that supports the new versions of OData Core, Edm, and Spatial libraries.
  - Jędrzej Dankowski June 2, 2024
    
    Hi there! When do you plan to release the mentioned version of Microsoft.AspNetCore.OData with all the support? Thanks
    - Clément Habinshuti Author June 2, 2024
      
      We’ll release a new preview version of Microsoft.AspNetCore.OData by June 7 based on the recently released Microsoft.OData.Core 8.0.0-preview.3
      - bytefish June 6, 2024
        
        I have been able to update to the latest preview3 versions. It worked without any problems. Great work! 👍