Inheritance: ContentCollectionPortlet
        protected virtual string SetEmptyFieldValue(ContentSearchPortlet.EmptyQueryTermHandler mode, Field field)
        {
            if (mode == ContentSearchPortlet.EmptyQueryTermHandler.ReplaceToWildcard)
            {
                if(field is DateTimeField)
                    return string.Format("{{{0} TO {1}}}", DateTime.MinValue, DateTime.MaxValue);
                if(field is IntegerField)
                    return string.Format("{{{0} TO {1}}}", int.MinValue, int.MaxValue);
                return "*";
            }

            if (mode == ContentSearchPortlet.EmptyQueryTermHandler.RemoveEmpty)
                return ContentQuery.EmptyText;

            return string.Empty;
        }
 public DefaultQueryBuilder(string originalQuery, Content searchForm,ContentSearchPortlet.EmptyQueryTermHandler emptyTerm)
 {
     _originalQuery = originalQuery;
     _searchForm = searchForm;
     _emptyTermHandler = emptyTerm;
 }