In ASP.NET MVC 2 - How do I get Route Values into my navigation controller so I can highlight the current link?

Question

I'm trying to get the current Route into my navigation controller so I can run comparisons as the navigation menu data is populated.

My Links object is like this:

public class StreamNavLinks
{
    public string Text { get; set; }
    public RouteValueDictionary RouteValues { get; set; }
    public bool IsSelected { get; set; }
}

In the master page, I'm trying to pass the current route to the nav controller like this:

<% Html.RenderAction(
    "MenuOfStreamEntries", // action
    "Nav", // controller
    new { // parameters for action
        currentStreamUrl = "Blog", 
        currentRoute = ViewContext.RouteData } // get route data to compare in controller
); %>

The problem that I'm running into is that I can't figure out how to get any of the data out of currentRoute. What is the best technique for getting the values out or currentRoute?

I've tried syntax like this:

 currentRoute.Values.routevaluename

and

 currentRoute.Values[0]

But I can't seem to get it to work.

Edit

I have also tried placing this code into the action of the navigation controller:

var current = RouteData["streamUrl"];

and

var current = this.RouteData["streamUrl"];

Both versions give me this error:

Error 1 Cannot apply indexing with [] to an expression of >type 'System.Web.Routing.RouteData' C:\pathtocontroller\NavController.cs 25 27

Edit 2

It also might be helpful to know the route values that I'm trying to match against:

        routes.MapRoute(null, "", // Only matches the empty URL (i.e. ~/)
                        new
                        {
                            controller = "Stream",
                            action = "Entry",
                            streamUrl = "Pages",
                            entryUrl = "HomePage"
                        }
        );

        routes.MapRoute(null, "{streamUrl}/{entryUrl}", // matches ~/Pages/HomePage
                        new { controller = "Stream", action = "Entry" }
        );

So, ultimately mydomain.com/blog/blogentry1 would map to the same controller/action as mydomain.com/pages/welcome. I'm not looking for the controller value or the action value, rather I'm looking for streamUrl value and EntryUrl value.

Answer 1

You don't need to pass route data to a controller because the controller already has knowledge of it via the RouteData property:

public ActionResult Index() {
    // You could use this.RouteData here
    ...
}

Now if you want to pass some simple arguments like current action that was used to render the view you could do this:

<%= Html.RenderAction(
    "MenuOfStreamEntries",
    "Nav",
    new {
        currentStreamUrl = "Blog", 
        currentAction = ViewContext.RouteData.Values["action"],
        currentController = ViewContext.RouteData.Values["controller"]
    }
); %>

And in your controller:

public ActionResult Nav(string currentAction, string currentController) 
{
    ...
}

Answer 2

Here is a nice post on how you can achieve this using Extension methods.

http://geekswithblogs.net/bdiaz/archive/2010/04/09/handy-asp.net-mvc-2-extension-methods-ndash-where-am-i.aspx

Answer 3

Here's a sample method we wrote for doing something similar.

public static bool IsCurrentAction(this HtmlHelper helper, string actionName, string controllerName)
        {
            string currentControllerName = (string)helper.ViewContext.RouteData.Values["controller"];
            string currentActionName = (string)helper.ViewContext.RouteData.Values["action"];

            if (currentControllerName.Equals(controllerName, StringComparison.CurrentCultureIgnoreCase) && currentActionName.Equals(actionName, StringComparison.CurrentCultureIgnoreCase))
                return true;

            return false;
        }