gistfile1.cs

public class YomegoCMSRouteConstraint : IRouteConstraint
{
    public bool Match(HttpContextBase httpContext, Route route, string parameterName, RouteValueDictionary values, RouteDirection routeDirection)
    {
        return IsRoutable(httpContext);
    }

    private bool PopulateContext(CoreApp<CoreServiceContainer> app, HttpContextBase context, string url, UmbracoRouteAttribute contentType = null)
    {
        // [ML ] -If this request has previously been routed, do nothing and route as context is populated

        if (context.Items[Requests.Routed] == null)
        {
            // [ML] - if this is a new request try and find the content

            PublishedContentModel content = null;

            if (UmbracoContext.Current != null)
            {
                try
                {
                    content = app.Services.Content.Get(url);
                }
                catch
                {
                    // [ML] - Suppress as if there is no context then this will blow up
                }
            }

            if (content != null)
            {
                context.Items[Requests.Node] = content;
                context.Items[Requests.PageId] = content.Id; // [ML] - Required to hook up umbraco Jazz

                // [ML] - Try and find a custom route if required

                if (contentType == null)
                {
                    contentType =
                        content.GetType().GetCustomAttributes(typeof (UmbracoRouteAttribute), true).FirstOrDefault()
                            as UmbracoRouteAttribute;
                }

                /* [ML] - If the page is found in Umbraco then add the node to the request items
                 *        and route the request to the action and controller set in umbraco */

                if (contentType != null)
                {
                    MLWDRouteTable.AddRoute(url, contentType);

                    if (string.IsNullOrWhiteSpace(contentType.Controller))
                    {
                        throw new ArgumentNullException(string.Format(
                            "The controller must be defined for type ({0}) to route.", content.GetType().Name));
                    }

                    
                    context.Items[Requests.ContentType] = contentType;
                    context.Items[Requests.Routed] = true;

                    return true;
                }
            }
            
            if (contentType == null)
            {
                return false;
            }
        }

        return true;
    }

    public bool IsRoutable(HttpContextBase context)
    {
        // [ML] - Try and get the content from the umbraco Api
        var app = new CoreApp<CoreServiceContainer>();

        var url = HttpContext.Current.Request.RawUrl.Split('?')[0];

        var contentType = MLWDRouteTable.GetFromUrl(url);

        return PopulateContext(app, context, url, contentType);
    }
}