How to get an Absolute URLs in ASP.NET MVC without HttpContext and/or UrlHelper

AbsoluteUrl.cs

public static class AbsoluteUrl
{
    private static bool initializedAlready = false;
    private static Object initlock = new Object();

    // AbsoluteUrl without parameters
    public static string MVC_Home_Index;
    public static string MVC_MyArea_Settings_Index;

    // AbsoluteUrl with parameters
    public static string MVC_MyArea_Settings_Edit_replacable;
    public static string MVC_MyArea_Settings_Edit(Guid? id)
    {
        // "You must define a specific route for JavaScriptReplacableUrl to work", but it doesn't work for me. So I use this:
        return MVC_MyArea_Settings_Edit_replacable + "?" + MVC.MyArea.Settings.EditParams.id + "=" + id.ToString();
    }

    /// <summary>
    /// Initialize only on the first request
    /// </summary>
    /// <param name="context"></param>
    public static void Initialize(System.Web.HttpContext context)
    {
        if (initializedAlready)
        {
            return;
        }

        lock (initlock)
        {
            if (initializedAlready)
            {
                return;
            }

            var url = new UrlHelper(context.Request.RequestContext);
            var leftPart = context.Request.Url.GetLeftPart(UriPartial.Authority);

            // AbsoluteUrl without parameters
            MVC_Home_Index = url.ActionAbsolute(MVC.Home.Index());
            MVC_MyArea_Settings_Index = url.ActionAbsolute(MVC.MyArea.Settings.Index());

            // AbsoluteUrl with parameters
            MVC_MyArea_Settings_Edit_replacable = leftPart + url.JavaScriptReplacableUrl(MVC.MyArea.Settings.Edit());

            initializedAlready = true;
        }
    }
}

example.cs

/*
  Now you don't need System.Web.HttpContext.Current nor System.Web.Mvc.UrlHelper to get Absolute URL in your application
*/

public class Example
{
  void TestIt()
  {
      Task<string> t = Task<string>.Run(() =>
      {
        // Now you can access absolute URL also in this thread without HttpContext
        
        // returns: http://www.mydomain.com/home/
        return AbsoluteUrl.MVC_Home_Index;
        
        // returns: http://www.mydomain.com/my/settings/
        return AbsoluteUrl.MVC_MyArea_Settings_Index;
        
        // returns: http://www.mydomain.com/my/settings/edit?id=00000000-0000-0000-0000-000000000000
        return AbsoluteUrl.MVC_MyArea_Settings_Edit(Guid.Empty);
      });
  }
}

Global.asax.cs

public class MvcApplication : System.Web.HttpApplication
{
  void Application_BeginRequest(object sender, EventArgs e)
  {
      // Attempt to perform first request initialization
      AbsoluteUrl.Initialize(this.Context);
  }
}

howto.md

How to get an Absolute URLs in ASP.NET MVC without HttpContext and/or UrlHelper

Using T4MVC (https://t4mvc.codeplex.com/) you must have HttpContext to resolve an URL in your application. So it won't work in a different thread for example. So I found this solution. I'm editing this by hand now, but I propose it as a new feature to integrate directly into T4MVC (https://t4mvc.codeplex.com/discussions/444764) .

One can now get an absolute URL of actions in a different thread and don't need an HttpContext nor UrlHelper .

I'm using this with FluentScheduler ( https://github.com/jgeurts/FluentScheduler ) for some background tasks like sending emails with RazorEngine and so.