Question

I have an area which is registered as:

public override void RegisterArea(AreaRegistrationContext context) {
    context.MapRoute("CPanel_default",
        "CPanel/{controller}/{action}/{id}/{*urlData}",
        new { id = UrlParameter.Optional, urlData = UrlParameter.Optional });
}

This route is intended to full a number of urls:

• /cpanel/home/index
• /cpanel/entity/edit/20
• /cpanel/entity/edit/20/abitrary-url-data

Haack’s route debugger has shown me that the route is functioning in this capacity. However, my code for generating action links has recently broken and I haven’t been able to find out the cause of the break.

Action links are being generated with the following code:

public static MvcHtmlString CpanelLink(this HtmlHelper @this, string linkText, 
    string actionName, string controllerName, string areaName = "CPanel") {

    return @this.ActionLink(linkText, 
        actionName, new { controller = controllerName, area = areaName });
}

Which, as far as I can tell, should account for all the required fields in the area route. Debugging shows that CpanelLink is returning <a href="">...</a>, a link to nothing.

Edit

Additional troubleshooting has reveled that the route parameter {*urlData} is killing Html.CpanelLink. Reducing the route to “CPanel/{controller}/{id}” clears the issue, but breaks urls which depend on the urlData parameter.

Answer 1

The problem is you can’t pass the controller name in as a route parameter.

You need to use the following ActionLink() method signature

return @this.ActionLink(linkText, actionName, controllerName, new { area = areaName }, null);

Note the last parameter value is ‘null’ which represents the html attributes.

UPDATE:

The other problem is to do with consecutive optional parameters, as described in Phil Haack’s blog post

So you need to do the workaround as such;

 context.MapRoute(
                "Route_withUrl",
                "CPanel/{controller}/{action}/{id}/{urlData}",
                new { controller = "Home", action = "Index" }
            );

            context.MapRoute(
                "Cpanel_default",
                "CPanel/{controller}/{action}/{id}",
                new { controller = "Home", action = "Index", id = UrlParameter.Optional}
            );