public object Convert(object value, Type targetType, object parameter, string language)
{
if (value is ArcGISPortalItem && targetType == typeof (string))
return ConvertPortalItemToHtmlString((ArcGISPortalItem) value);
if (value is ArcGISPortalGroup && targetType == typeof(string))
return ConvertPortalGroupToHtmlString((ArcGISPortalGroup)value);
return value;
}