WebAPI and ODataController return 406 Not Acceptable

Question

Before adding OData to my project, my routes where set up like this:

       config.Routes.MapHttpRoute(
            name: \"ApiById\",
            routeTempl         


        

Answer 1

Found in the GitHub error: "Unable to use odata $select, $expand, and others by default #511", their solution is to put the following line BEFORE registering the route:

// enable query options for all properties
config.Filter().Expand().Select().OrderBy().MaxTop(null).Count();

Worked like a charm for me.

Source: https://github.com/OData/RESTier/issues/511

Answer 2

If you are using OData V4, replace using System.Web.Http.OData;

With using Microsoft.AspNet.OData; (Please check the comments for the latest library)

in the ODataController works for me.

Answer 3

In my case (odata V3) I had to change name of OdataController to be same as provided in ODataConventionModelBuilder and that solved the issue

my controller:

public class RolesController : ODataController
{
    private AngularCRMDBEntities db = new AngularCRMDBEntities();

    [Queryable]
    public IQueryable<tROLE> GetRoles()
    {
        return db.tROLEs;
    }
}

ODataConfig.cs:

public class ODataConfig
{
    public static void Register(HttpConfiguration config)
    {
        ODataConventionModelBuilder modelBuilder = new ODataConventionModelBuilder();
        modelBuilder.EntitySet<WMRole>("RolesNormal"); 
        modelBuilder.EntitySet<WMCommon.DAL.EF.tROLE>("Roles").EntityType.HasKey(o => o.IDRole).HasMany(t => t.tROLE_AUTHORIZATION);
        modelBuilder.EntitySet<WMCommon.DAL.EF.tLOOKUP>("Lookups").EntityType.HasKey(o => o.IDLookup).HasMany(t => t.tROLE_AUTHORIZATION);
        modelBuilder.EntitySet<WMCommon.DAL.EF.tROLE_AUTHORIZATION>("RoleAuthorizations").EntityType.HasKey(o => o.IDRoleAuthorization);

        config.Routes.MapODataRoute("odata", "odata", modelBuilder.GetEdmModel());
        config.EnableQuerySupport();
    }
}

WebApiConfig.cs:

public static class WebApiConfig
{
    public static void Register(HttpConfiguration config)
    {
        // Web API configuration and services

        // Web API routes
        config.MapHttpAttributeRoutes();
        config.SuppressDefaultHostAuthentication();
        config.Filters.Add(new HostAuthenticationFilter(OAuthDefaults.AuthenticationType));            

        config.Routes.MapHttpRoute( //MapHTTPRoute for controllers inheriting ApiController
            name: "DefaultApi",
            routeTemplate: "api/{controller}/{id}",
            defaults: new { id = RouteParameter.Optional }
            );

        var jsonFormatter = config.Formatters.OfType<JsonMediaTypeFormatter>().First();
        jsonFormatter.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();

        GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings
            .ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore;
        GlobalConfiguration.Configuration.Formatters
            .Remove(GlobalConfiguration.Configuration.Formatters.XmlFormatter);
    }
}

Global.asax:

public class WebApiApplication : System.Web.HttpApplication
{
    protected void Application_Start()
    {
        GlobalConfiguration.Configure(config =>
        {
            ODataConfig.Register(config); 
            WebApiConfig.Register(config);
        });            
    }
}

Answer 4

My issue was related to returning the entity model instead of the model I exposed (builder.EntitySet<ProductModel>("Products");). Solution was to map entity to resource model.

Answer 5

The order in which the routes are configured has an impact. In my case, I also have some standard MVC controllers and help pages. So in Global.asax:

protected void Application_Start()
{
    AreaRegistration.RegisterAllAreas();
    GlobalConfiguration.Configure(config =>
    {
        ODataConfig.Register(config); //this has to be before WebApi
        WebApiConfig.Register(config); 

    });
    FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
    RouteConfig.RegisterRoutes(RouteTable.Routes);
}

The filter and routeTable parts weren't there when I started my project and are needed.

ODataConfig.cs:

public static void Register(HttpConfiguration config)
{
    config.MapHttpAttributeRoutes(); //This has to be called before the following OData mapping, so also before WebApi mapping

    ODataConventionModelBuilder builder = new ODataConventionModelBuilder();

    builder.EntitySet<Site>("Sites");
    //Moar!

    config.MapODataServiceRoute("ODataRoute", "api", builder.GetEdmModel());
}

WebApiConfig.cs:

public static void Register(HttpConfiguration config)
{
    config.Routes.MapHttpRoute( //MapHTTPRoute for controllers inheriting ApiController
            name: "DefaultApi",
            routeTemplate: "api/{controller}/{id}",
            defaults: new { id = RouteParameter.Optional }
    );
}

And as a bonus, here's my RouteConfig.cs:

public static void RegisterRoutes(RouteCollection routes)
{
    routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

    routes.MapRoute( //MapRoute for controllers inheriting from standard Controller
        name: "Default",
        url: "{controller}/{action}/{id}",
        defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }
    );
}

This has to be in that EXACT ORDER. I tried moving the calls around and ended up with either MVC, Api or Odata broken with 404 or 406 errors.

So I can call:

localhost:xxx/ -> leads to help pages (home controller, index page)

localhost:xxx/api/ -> leads to the OData $metadata

localhost:xxx/api/Sites -> leads to the Get method of my SitesController inheriting from ODataController

localhost:xxx/api/Test -> leads to the Get method of my TestController inheriting from ApiController.

Answer 6

None of the excellent solutions on this page worked for me. By debugging, I could see that the route was getting picked up and the OData queries were running correctly. However, they were getting mangled after the controller had exited, which suggested that it was the formatting that was generating what appears to be the OData catch-all error: 406 Not Acceptable.

I fixed this by adding a custom formatter based on the Json.NET library:

public class JsonDotNetFormatter : MediaTypeFormatter
{
    public JsonDotNetFormatter()
    {
        SupportedMediaTypes.Add(new MediaTypeHeaderValue("application/json"));
    }

    public override bool CanReadType(Type type)
    {
        return true;
    }

    public override bool CanWriteType(Type type)
    {
        return true;
    }

    public override async Task<object> ReadFromStreamAsync(Type type, Stream readStream, HttpContent content, IFormatterLogger formatterLogger)
    {
        using (var reader = new StreamReader(readStream))
        {
            return JsonConvert.DeserializeObject(await reader.ReadToEndAsync(), type);
        }
    }

    public override async Task WriteToStreamAsync(Type type, object value, Stream writeStream, HttpContent content, TransportContext transportContext)
    {
        if (value == null) return;
        using (var writer = new StreamWriter(writeStream))
        {
            await writer.WriteAsync(JsonConvert.SerializeObject(value, new JsonSerializerSettings {ReferenceLoopHandling = ReferenceLoopHandling.Ignore}));
        }
    }

Then in WebApiConfig.cs, I added the line config.Formatters.Insert(0, new JsonDotNetFormatter()). Note that I am sticking closely to the order described in Jerther's answer.

public static class WebApiConfig
{
    public static void Register(HttpConfiguration config)
    {
        ConfigureODataRoutes(config);
        ConfigureWebApiRoutes(config);
    }

    private static void ConfigureWebApiRoutes(HttpConfiguration config)
    {
        config.Routes.MapHttpRoute("DefaultApi", "api/{controller}/{id}", new { id = RouteParameter.Optional });
    }

    private static void ConfigureODataRoutes(HttpConfiguration config)
    {
        config.MapHttpAttributeRoutes();
        config.Formatters.Insert(0, new JsonDotNetFormatter());
        var builder = new ODataConventionModelBuilder();
        builder.EntitySet<...>("<myendpoint>");
        ...
        config.MapODataServiceRoute("ODataRoute", "odata", builder.GetEdmModel());
    }
}