//Builds URL by finding the best matching route that corresponds to the current URL,
//with given parameters added or replaced.
public static System.Web.Mvc.MvcHtmlString Current(this System.Web.Mvc.UrlHelper helper, object substitutes)
{
//get the route data for the current URL e.g. /Research/InvestmentModelling/RiskComparison
//this is needed because unlike UrlHelper.Action, UrlHelper.RouteUrl sets includeImplicitMvcValues to false
//which causes it to ignore current ViewContext.RouteData.Values
var rd = new System.Web.Routing.RouteValueDictionary(helper.RequestContext.RouteData.Values);
//get the current query string e.g. ?BucketID=17371&compareTo=123
var qs = helper.RequestContext.HttpContext.Request.QueryString;
//add query string parameters to the route value dictionary
foreach (string param in qs)
{
if (!string.IsNullOrEmpty(qs[param]))
{
rd[param] = qs[param];
}
}
//override parameters we're changing
foreach (
System.ComponentModel.PropertyDescriptor property in
System.ComponentModel.TypeDescriptor.GetProperties(substitutes.GetType()))
{
var value = property.GetValue(substitutes);
if (value == null)
{
rd.Remove(property.Name);
}
else
{
rd[property.Name] = value;
}
}
//UrlHelper will find the first matching route
//(the routes are searched in the order they were registered).
//The unmatched parameters will be added as query string.
var url = helper.RouteUrl(rd);
return(new System.Web.Mvc.MvcHtmlString(url));
}