AjaxOnly Attribute fot ASP.NET MVC Controller's method

AjaxOnlyAttribute.cs

using System.Reflection;
using System.Web.Mvc;

namespace SolutionName.Helpers
{
    // request must be ajax
    // used with controller methods
    public class AjaxOnlyAttribute : ActionMethodSelectorAttribute
    {
        public override bool IsValidForRequest(ControllerContext controllerContext, MethodInfo methodInfo)
        {
            return controllerContext.RequestContext.HttpContext.Request.IsAjaxRequest();
        }
    }
}

/*
How to use ?
- write [AjaxOnly] before the method

[AjaxOnly]
public JsonResult MethodName()
{
    ...
}
*/