Sitecore Friendly URL Computed Field

FriendlyUrl.cs

using System.Xml;
using Sitecore.ContentSearch;
using Sitecore.ContentSearch.ComputedFields;
using Sitecore.Data.Items;
using Sitecore.Links;
using Sitecore.Xml;

namespace MikeRobbins.ContentSearch.ComputedFields
{
    public class FriendlyUrl : AbstractComputedIndexField
    {
        public override object ComputeFieldValue(IIndexable indexable)
        {
            var scIndexable = indexable as SitecoreIndexableItem;
            if (scIndexable != null)
            {
                var item = (Item)scIndexable;
                if (item != null)
                {
                    var opts = LinkManager.GetDefaultUrlOptions();
                    opts.Site = Sitecore.Sites.SiteContext.GetSite(SiteName);
                    return LinkManager.GetItemUrl(item, opts);
                }
            }
            return null;
        }

        public FriendlyUrl()
        {
        }

        public FriendlyUrl(XmlNode configurationNode) : this()
        {
             SiteName = XmlUtil.GetAttribute("siteName", configurationNode);
        }

        public string SiteName { get; set; }
    }
}

FriendlyUrlContentSearch.config

<fields hint="raw:AddComputedIndexField">
  <field fieldName="urllink" siteName="SiteName">MikeRobbins.ContentSearch.ComputedFields.FriendlyUrl,MikeRobbins.ContentSearch</field>
</fields>