Webapi: [Bug] Functions returning entity types with contained properties throw exception

[vojtechvit]

Description

Functions that return entity types with properties that are contained entity sets throw exception when invoked.

Minimal repro steps

• Create an empty ASP.NET website hosted on OWIN SystemWeb
• Create an EmailAddress class with property [Key] Address : string
• Create a User class with properties Id : int and [Contained] EmailAddresses : ICollection<EmailAddress>
• Add Web API OData, register it with a model that contains:
  
  
  
  • Entity set _Users_ of type User
  
  
  • Function _ByAddress_ defined on a collection of User with a parameter address : string, returning a single entity from entity set _Users_
  
  
• Create a controller and action for function _ByEmailAddress_ and some sample implementation returning some actual data (non-empty result!).
• Try to call the function endpoint _ByEmailAddress_ with parameter address set to an existing e-mail address.
  

  Expected result

A single entity of type User.

Actual result

An exception:

{
    "error": {
        "code": "",
        "message": "An error has occurred.",
        "innererror": {
            "message": "The Path property in ODataMessageWriterSettings.ODataUri must be set when writing contained elements.",
            "type": "Microsoft.OData.Core.ODataException",
            "stacktrace": " at Microsoft.OData.Core.ODataWriterCore.EnterScope(WriterState newState, ODataItem item)\ \ at Microsoft.OData.Core.ODataWriterCore.WriteStartNavigationLinkImplementation(ODataNavigationLink navigationLink)\ \ at Microsoft.OData.Core.ODataWriterCore.WriteStart(ODataNavigationLink navigationLink)\ \ at System.Web.OData.Formatter.Serialization.ODataEntityTypeSerializer.WriteNavigationLinks(IEnumerable`1 navigationProperties, EntityInstanceContext entityInstanceContext, ODataWriter writer)\ \ at System.Web.OData.Formatter.Serialization.ODataEntityTypeSerializer.WriteEntry(Object graph, ODataWriter writer, ODataSerializerContext writeContext)\ \ at System.Web.OData.Formatter.Serialization.ODataEntityTypeSerializer.WriteObjectInline(Object graph, IEdmTypeReference expectedType, ODataWriter writer, ODataSerializerContext writeContext)\ \ at System.Web.OData.Formatter.Serialization.ODataEntityTypeSerializer.WriteObject(Object graph, Type type, ODataMessageWriter messageWriter, ODataSerializerContext writeContext)\ \ at System.Web.OData.Formatter.ODataMediaTypeFormatter.WriteToStream(Type type, Object value, Stream writeStream, HttpContent content, HttpContentHeaders contentHeaders)\ \ at System.Web.OData.Formatter.ODataMediaTypeFormatter.WriteToStreamAsync(Type type, Object value, Stream writeStream, HttpContent content, TransportContext transportContext, CancellationToken cancellationToken)\ \ --- End of stack trace from previous location where exception was thrown ---\ \ at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\ \ at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\ \ at System.Web.Http.Owin.HttpMessageHandlerAdapter.<BufferResponseContentAsync>d__13.MoveNext()"
        }
    }
}

Further technical details

Sample code

var modelBuilder = new ODataConventionModelBuilder();

var userType = modelBuilder.EntityType<User>();
var byEmailAddressFunction = userType.Collection.Function("byEmailAddress");
byEmailAddressFunction.Parameter<string>("address");
byEmailAddressFunction.ReturnsFromEntitySet<User>("Users");

modelBuilder.EntitySet<User>("Users");


public class User
{
    public int Id { get; set; }

    [Contained]
    public ICollection<EmailAddress> EmailAddresses { get; set; }
}


public class EmailAddress
{
    [Key]
    public string Address { get; set; }
}


    [HttpGet]
    public IHttpActionResult ByEmailAddress(string address)
    {
        if (address == null)
        {
            return BadRequest();
        }

        var user = _users.FirstOrDefault(u => 
            u.EmailAddresses.Any(a =>
                a.Address.Equals(address, StringComparison.InvariantCulture)));

        if (user == null)
        {
            return NotFound();
        }

        return Ok(user);
    }

[vojtechvit]

I created a fork and a branch with a fix to this issue: https://github.com/vojtechvit/odata.net/commits/bugfix/containedentityinfunction

_However - I'm not fully aware of the internal mechanics of the complex ODataWriterCore class, so please consider this code just as a highlight of the problem area!_

For instance, I'm not persuaded that it generates all correct path segments (e.g. entity key segments are missing).

[vojtechvit]

It would be great if you could include the bugfix already in the 5.5 release! O:-)

[jogonzal]

Is there an ETA for this fix?

[xuzhg]

ODataMediaTypeFormatter has codes as:

``` C#
writerSettings.ODataUri = new ODataUri
{
ServiceRoot = baseAddress,

    // TODO: 1604 Convert webapi.odata's ODataPath to ODL's ODataPath, or use ODL's ODataPath.
   SelectAndExpand = Request.ODataProperties().SelectExpandClause,
   Path = (path == null || IsOperationPath(path)) ? null : path.ODLPath,

};

Where `IsOperationPath(path)` returns `true` because it's a function call, therefore `Path` in the `writerSettings.ODataUri` is null. 

While, in ODL, `ODataWriterCore` need `Path` in the `writerSettings.ODataUri` to be set, otherwise it will throw the ODataException. However, it's hard to calculate the path for the returned entity of a function.

Therefore, It's better to set the path by yourself (the developer) in the controller. Below's the workaround and it can work at my side:

``` C#
[HttpGet]
public IHttpActionResult ByEmailAddress(string address)
 {
            if (address == null)
            {
                return BadRequest();
            }

            var user = _users.FirstOrDefault(u =>
                u.EmailAddresses.Any(a =>
                    a.Address.Equals(address, StringComparison.InvariantCulture)));

            if (user == null)
            {
                return NotFound();
            }

            IEdmModel model = Request.ODataProperties().Model;

            ODataPath path = new DefaultODataPathHandler().Parse(model, "http://localhost:44567/odata/", "Users(1)");

            Request.ODataProperties().Path = path;

            return Ok(user);
        }

Please replace the service root and odataPath parameter values as your own string.

Please re-open it if you have further concern.

[patrickmichalina]

Using the new libraries would require something like:

```c#
var path = new DefaultODataPathHandler().Parse("http://localhost:44567/odata/v1", "MyEntityRoute", Request.GetRequestContainer());

Request.ODataProperties().Path = path;
```

[noah-freitas]

+1 for a fix for this.

I run into this issue whenever I try to return a newly created entity set record from an unbound action.

[mttwc]

+1. Is there an ETA for a fix? This issue is repro'ing for me despite the Path being set in Request.ODataProperties() with the correct value.

[pareman]

+1. is there any ETA for this fix?

[balent]

Thanks for the workaround.

Setting Request.ODataProperties().Path worked for me.

+1 for fixing the issue or providing some documentation so engineers are aware of this behavior.

[maximpashuk]

I am also failing into this issue :(
@xuzhg, can I ask your attention please.

@vojtechvit created a pull request for fixing this issue in odata.net repo
https://github.com/OData/odata.net/pull/111

I don't know why this pull request is not merged and just closed, I saw the code and it looks good for me.
Can you spent some time on this issue?
This issue is still actual in Microsoft.AspNetCore.OData 7.0.1.

[jannikbuschke]

Im also facing this issue

[nathan-swannet]

also still facing this bug on Microsoft.AspNetCore.OData 7.0.1.

[maximpashuk]

But still workaround works for me in Microsoft.AspNetCore.OData 7.0.1

var path = Request.GetPathHandler().Parse("http://localhost/odata/", "users(1)", request.GetRequestContainer());
Request.ODataFeature().Path = path;

[Mortana89]

Also facing this one here!

[emturner]

also facing this!

[NetTecture]

Whow. 3 years open and still not fixed. Meanwhile anyone has a decent solution for dotnet core? I just added a contained entity set and boom - "unrelated" functionality blowing.

[cfauchere]

Request.ODataProperties().Path does not seem to be available in Microsoft.AspNetCore.OData.
Could you please advise?

[crackalak]

As above, the workaround for .net core is:

var path = Request.GetPathHandler().Parse("http://localhost/odata/", "users(1)", request.GetRequestContainer());
Request.ODataFeature().Path = path;

[jannikbuschke]

Running now also into this. A higher priorisation of this bug would be greatly appreciated.

@crackalak does your workaround still work for you?

My code looks like this, but fails:

 public class ClientsController : ODataController
    {
        private readonly DataContext ctx;

        public ClientsController(
            DataContext ctx
        )
        {
            this.ctx = ctx;
        }

        [EnableQuery]
        public IQueryable<Client> Get(string search)
        {
            return ctx.Clients;
        }

        [EnableQuery]
        public SingleResult<Client> Get([FromODataUri] Guid key)
        {
            IQueryable<Client> result = ctx.Clients.Where(p => p.Id == key);
            return SingleResult.Create(result);
        }

        [EnableQuery]
        [HttpGet]
        public IEnumerable<Client> TestData()
        {
            var path = Request.GetPathHandler().Parse("https://localhost:5001/odata/", "clients/TestData", Request.GetRequestContainer());
            Request.ODataFeature().Path = path;
            return new FakeClients().Get();
        }
    }

[lclamotte]

FYI for anyone coming across this in late 2020, looks like this has been fixed in WebAPI 7.5.0 (https://docs.microsoft.com/en-us/odata/changelog/webapi-7x) by PR 2060