Register global filters in ASP.Net MVC 4 and Autofac

Question

I have a filter like this one:

public class CustomFilterAttribute : ActionFilterAttribute, IAuthorizationFilter
{
    public MyPropery Property { get; set; }
    ....
}

I need it to be run for every actions in my project

I tried to register it in the GlobalFilters but my property doesn't get injected

I tried This solution to register my filter but it doesn't get called

Any idea on how to do that?

Answer 1

There's a new way of registering MVC global filters in AutoFac. First, remove the filter registration from your RegisterGlobalFilters because we will have Autofac handle adding them to our controllers/actions instead of MVC.

Then, register your container as follows:

var builder = new ContainerBuilder();
builder.RegisterControllers(Assembly.GetExecutingAssembly());

builder.RegisterType<MyProperty>().As<IProperty>();

builder.Register(c => new CustomFilterAttribute(c.Resolve<IProperty>()))
                .AsActionFilterFor<Controller>().InstancePerHttpRequest();

builder.RegisterFilterProvider();

IContainer container = builder.Build();

DependencyResolver.SetResolver(new AutofacDependencyResolver(container));

Note that by passing in the Controller class into the extension AsActionFilterFor() we are telling AutoFac to apply this filter to all classes that derive from the Controller class (which, in MVC, is all controllers). Since we are calling AsActionFilterFor() without any arguments, we are also specifying we want to have the filter applied to all actions within the specified controllers. If you want to apply your filter to a select controller and action, you can use lambda expressions like so:

builder.Register(c => new CustomFilterAttribute(c.Resolve<IProperty>()))
    .AsActionFilterFor<HomeController>(c => c.Index())
    .InstancePerHttpRequest();

If your action takes a parameter, use the default keyword to specify:

builder.Register(c => new CustomFilterAttribute(c.Resolve<IProperty>()))
    .AsActionFilterFor<HomeController>(c => c.Detail(default(int)))
    .InstancePerRequest();

Note that you have to use a different extension method based on what type of filter you are registering, here are the supported filter types:

• AsActionFilterFor
• AsAuthorizationFilterFor
• AsExceptionFilterFor
• AsResultFilterFor

Answer 2

You should now use Pete's solution now to do this. Thanks to him for an updated solution.

I finally made it, here is how to do it:

First create your attribute with a constructor with all dependencies

public class CustomFilterAttribute : ActionFilterAttribute, IAuthorizationFilter
{
    private IProperty _property;

    public CustomFilterAttribute(IProperty repository)
    {
        _property = property;
    }
    ....
 }

Register everything you need in autofac

var builder = new ContainerBuilder();
builder.RegisterControllers(Assembly.GetExecutingAssembly());

builder.RegisterType<MyProperty>().As<IProperty>();
builder.RegisterType<CustomFilterAttribute>().SingleInstance();

builder.RegisterFilterProvider();

IContainer container = builder.Build();

DependencyResolver.SetResolver(new AutofacDependencyResolver(container));

Register your global filter like that

public static void RegisterGlobalFilters(GlobalFilterCollection filters)
{
    filters.Add(new HandleErrorAttribute());
    filters.Add(DependencyResolver.Current.GetService<CustomFilterAttribute>());
}

Make sure in your global.asax you register first Autofac and then the global filters.

Now, you don't need property injection anymore, constructor injection will work fine which is a good thing!