WebApi Action filter called twice

Question

My WebApi filter method OnActionExecuted is being called twice. My filter (I make it as simple as possible):

   public class NHibernateActionFilter : ActionFilterAttribute
   { 
        //  [Inject]
        //   public ISessionFactoryProvider sessionFactoryProvider { get; set; }
        public override void OnActionExecuted(HttpActionExecutedContext actionExecutedContext)
        {
           var a = 5;
           var b = a;
           //new BaseSessionProvider(sessionFactoryProvider).EndContextSession();
        }
    }

My setup:

    protected void Application_Start()
    {
        AreaRegistration.RegisterAllAreas();
        WebApiConfig.Register(GlobalConfiguration.Configuration);
        //http://stackoverflow.com/questions/9521040/how-to-add-global-asp-net-web-api-filters
        FilterConfig.RegisterWebApiFilters(GlobalConfiguration.Configuration.Filters);
    }

    public class FilterConfig
    {

        public static void RegisterWebApiFilters(System.Web.Http.Filters.HttpFilterCollection filters)
        {
             filters.Add(new NHibernateActionFilter());
        }
     }

In debugger I catch OnActionExecuted twice with the same actionExecutedContext. Why?

UPD

Controller
public class BankSmsController : ApiController
{
         [AcceptVerbs(HttpVerbs.Get)]
         public int GetTest()
         {
             return 1;
         }
}

I noticed an `Inject` attribute commented out - could there be some NInject config that sets up filters as well so it's being added twice? Have you confirmed that there is only one instance of the filter in the global filters collection after all the startup code has finished running? — levelnis, Aug 28 '13 at 10:56
No ninject at all. I remove `kernel.BindFilter(FilterScope.Global, 1);` — Andrew Kalashnikov, Aug 28 '13 at 12:15
May be you have `[NHibernateActionFilter]` directly on your controller and in global filter. Therefore it is executed twice. — Vladimir, Aug 29 '13 at 09:58

score 8 · Answer 1 · answered Feb 11 '14 at 17:52

8

I have a suspicion, that this strange behavior can be fixed by either overriding AllowMultiple property of filter and returning false, or applying AttributeUsage attribute with AllowMultiple set to false too (this influences on default implementation of AllowMultiple property of filter.

At least in our project this helped (we have filters injected via Autofac).

answered Feb 11 '14 at 17:52

Mikhail Brinchuk

647
6
16

7

Using `AllowMultiple` is more like a hack, something is registering the action filter twice. – Daniel Little Apr 06 '14 at 02:49
@DanielLittle what could be the potential culprit? – Marin Jul 18 '14 at 16:49
3

Personally I had the attribute defined once in my `WebApiConfig` file and once on my base controller class. – dee-see Jul 22 '14 at 19:08

jbernal · Answer 2 · 2015-10-15T10:17:19.443

3

This might be caused due to a registration of a custom filter provider. When you do this, you need to unregister the default one. Otherwise, if you are getting the usual filters in your custom one, they will be registered twice and consequently, executed twice.

Code should be something like this:

// remove default action filter provider
var defaultFilterProvider = config.Services.GetFilterProviders().Single(provider => provider is ActionDescriptorFilterProvider);
config.Services.Remove(typeof(IFilterProvider), defaultFilterProvider);

// add custom filter provider
config.Services.Add(typeof(IFilterProvider), new CustomFilterProvider(container));

As have been said, AllowMultiple to false is a hack since .net is clever enough to only execute once a filter even if it has been registered several times. Also, there are scenarios where you do need this to be true.

edited Oct 15 '15 at 10:17

answered Oct 15 '15 at 10:11

jbernal

706
1
11
27

Thanks for this code but i coundn't able to find FilterProvider with ActionDesctiptorFilterProvider type it give me error Sequence contains no matching element – Niraj Trivedi Jan 29 '18 at 00:51
Depends on the actual application configuration, but all matching filters should be removed/replaced: `config.Services.RemoveAll(typeof(System.Web.Http.Filters.IFilterProvider), provider => provider is ActionDescriptorFilterProvider);` – Eugene Y. Nov 14 '18 at 02:12

score 2 · Answer 3 · edited May 26 '16 at 16:12

For me, I had specified the filter twice. In my IOC config file I had

builder.Register(c => new SelectListFilter(c.Resolve<ClientManager>()))
        .AsActionFilterFor<Controller>()
        .InstancePerRequest();
        .RegisterFilterProvider();

And then in filterConfig I had

filters.Add(DependencyResolver.Current.GetService<IActionFilter>());

I removed the line from filterConfig and everything was better.

WebApi Action filter called twice

3 Answers3

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