EPiServer 7 LinkItemCollection extension

I found it useful to have an extension method for the linkitemcollection, as it is often used in UL/LI lists.

This is for EPiServer CMS 7. It handles both EPi pages and external links.

C#:

     public static string GetItemsList(this LinkItemCollection links)  
     {  
       return GetItemsList(links, false);  
     }  
     /// <summary>  
     /// Returns a LI a href listing, with option for class "last" on the last li element  
     /// </summary>  
     /// <param name="links"></param>  
     /// <returns></returns>  
     public static string GetItemsList(this LinkItemCollection links, bool addClassLast)  
     {  
       StringBuilder sb = new StringBuilder("");  
       if (links == null || links.Count < 1)  
         return "";  
       int total = links.Count;  
       int counter = 1;  
       foreach (LinkItem linkItem in links)  
       {  
         UrlBuilder url = new UrlBuilder(linkItem.Href);  
         bool isEPiServerPage = PermanentLinkMapStore.ToMapped(url);  
         if (isEPiServerPage && PermanentLinkUtility.IsMappableUrl(url))  
         {  
           PageData page = DataFactory.Instance.GetPage(PageReference.Parse(url.QueryId));  
           if (page != null && !page.IsDeleted && page.CheckPublishedStatus(PagePublishedStatus.Published))  
           {  
             sb.Append(string.Format(GetPattern(addClassLast, counter, total), page.PageName, page.PageLink.GetFriendlyURL(), linkItem.Target));  
           }  
         }  
         else if (linkItem.Href.StartsWith("http"))  
         {  
           sb.Append(string.Format(GetPattern(addClassLast, counter, total), linkItem.Text, linkItem.Href, linkItem.Target));  
         }  
         counter++;  
       }  
       return sb.ToString();  
     }  
     static string GetPattern(bool addClassLast, int counter, int total)  
     {  
       if (addClassLast && counter == total)  
         return "<li class=\"last\"><a href=\"{1}\" target=\"{2}\">{0}</a></li>";  
       return "<li><a href=\"{1}\" target=\"{2}\">{0}</a></li>";  
     }