Question

How can I create a custom route constraint that will only match AJAX requests?

In a controller I can use Request.IsAjaxRequest().

How can I access IsAjaxRequest from my custom constraint? I’ve implemented the IRouteConstraint interface and the Match() method as follows:

public class IsAjaxConstraint : IRouteConstraint
{
    public bool Match(HttpContextBase httpContext,
                      Route route, 
                      string parameterName,
                      RouteValueDictionary values,
                      RouteDirection routeDirection)
    {            
     // How can I check for an Ajax request here?
    }
}

Answer 1

If you add this to your route constraint, does the httpContext.Request.IsAjaxRequest() work?

using System.Web.Mvc;

Request.IsAjaxRequest() is an extension method in System.Web.Mvc.