A class in PHP that converts strings into HTML entity references_PHP Tutorial

class HtmlEncode {
        static $_convertToHtmlEntitiesSrcEncoding='UTF-8';

        /**
* Convert non-ASCII strings into HTML entities
* *
* @example HtmlEncode::encode("I believe it"); //Output: I believe it
* @param string $ s The string to be encoded
* @return string Returns the HTML entity reference
*/
        public static function encode($s,$srcEncoding='UTF-8') {
            self::$_convertToHtmlEntitiesSrcEncoding=$srcEncoding;
            return preg_replace_callback('|[^x00-x7F]+|',array(__CLASS__,'_convertToHtmlEntities'),$s);
        }

        public static function _convertToHtmlEntities($data) {
            if (is_array($data)) {
                $chars=str_split(iconv(self::$_convertToHtmlEntitiesSrcEncoding,"UCS-2BE",$data[0]),2);
                $chars=array_map(array(__CLASS__,__FUNCTION__),$chars);
                return join("",$chars);
            } else {
                $code=hexdec(sprintf("%02s%02s;",dechex(ord($data {0})),dechex(ord($data {1}))));
                return sprintf("%s;",$code);
            }
        }     
    }