How do I get the Controller and Action names from the Referrer Uri?

Question

There\'s a lot of information for building Uris from Controller and Action names, but how can I do this the other way around?

Basically, all I\'m trying to achieve i

Answer 1

I think this should do the trick:

// Split the url to url + query string
var fullUrl = Request.UrlReferrer.ToString();
var questionMarkIndex = fullUrl.IndexOf('?');
string queryString = null;
string url = fullUrl;
if (questionMarkIndex != -1) // There is a QueryString
{    
    url = fullUrl.Substring(0, questionMarkIndex); 
    queryString = fullUrl.Substring(questionMarkIndex + 1);
}   

// Arranges
var request = new HttpRequest(null, url, queryString);
var response = new HttpResponse(new StringWriter());
var httpContext = new HttpContext(request, response)

var routeData = RouteTable.Routes.GetRouteData(new HttpContextWrapper(httpContext));

// Extract the data    
var values = routeData.Values;
var controllerName = values["controller"];
var actionName = values["action"];
var areaName = values["area"];

My Visual Studio is currently down so I could not test it, but it should work as expected.

Answer 2

To add to gdoran's accepted answer, I found that the action doesn't get populated if a custom route attribute is used. The following works for me:

public static void SetUpReferrerRouteVariables(HttpRequestBase httpRequestBase, ref string previousAreaName, ref string previousControllerName, ref string previousActionName)
{
    // No referrer found, perhaps page accessed directly, just return.
    if (httpRequestBase.UrlReferrer == null) return;

    // Split the url to url + QueryString.
    var fullUrl = httpRequestBase.UrlReferrer.ToString();
    var questionMarkIndex = fullUrl.IndexOf('?');
    string queryString = null;
    var url = fullUrl;
    if (questionMarkIndex != -1) // There is a QueryString
    {
        url = fullUrl.Substring(0, questionMarkIndex);
        queryString = fullUrl.Substring(questionMarkIndex + 1);
    }

    // Arrange.
    var request = new HttpRequest(null, url, queryString);
    var response = new HttpResponse(new StringWriter());
    var httpContext = new HttpContext(request, response);

    var routeData = RouteTable.Routes.GetRouteData(new HttpContextWrapper(httpContext));
    if (routeData == null) throw new AuthenticationRedirectToReferrerDataNotFoundException();

    // Extract the data.
    var previousValues = routeData.Values;
    previousAreaName = previousValues["area"] == null ? string.Empty : previousValues["area"].ToString();
    previousControllerName = previousValues["controller"] == null ? string.Empty : previousValues["controller"].ToString();
    previousActionName = previousValues["action"] == null ? string.Empty : previousValues["action"].ToString();
    if (previousActionName != string.Empty) return;
    var routeDataAsListFromMsDirectRouteMatches = (List<RouteData>)previousValues["MS_DirectRouteMatches"];
    var routeValueDictionaryFromMsDirectRouteMatches = routeDataAsListFromMsDirectRouteMatches.FirstOrDefault();
    if (routeValueDictionaryFromMsDirectRouteMatches == null) return;
    previousActionName = routeValueDictionaryFromMsDirectRouteMatches.Values["action"].ToString();
    if (previousActionName == "") previousActionName = "Index";
}

Answer 3

Why would you need to construct ActionLink from a url ? The purpose of ActionLink is just the opposite to make a url from some data. So in your page just do:

var fullUrl = Request.UrlReferrer.ToString();
<a href="@fullUrl">Back</a>