Typless Entity Patch operation in ODATA v4

Question

I'm workng on supporting the patch operation for a typeless entity in odata v4 with webapi.

So far the only thing that I was able to make work was the Put operation, but it requires the whole object to be present.

public HttpResponseMessage Put(IEdmEntityObject entity)
{
     return Request.CreateResponse(System.Net.HttpStatusCode.NoContent);
}

Whenever I change the Put verb to be a Patch, the entity object is null.

public HttpResponseMessage Patch(IEdmEntityObject entity)
{
     return Request.CreateResponse(System.Net.HttpStatusCode.NoContent);
}

I also tried replaceing the IEdmEntityObject with the types - Delta, Delta<IEdmEntityObject> and dynamic but i get the following exception

No MediaTypeFormatter is available to read an object of type 'Object' from content with media type 'application/json'

Answer 1

gebov

Update, for example PATCH/PUT is for a single entity. So, your action should have a key to identify which entity should to be updated.

Therefore, modify your action as:

public HttpResponseMessage Patch(int key, IEdmEntityObject entity)
{
   ...
}

It should work. See my test project. Thanks.