emoji.php

См. документацию.

<?php
namespace Bitrix\Main\Text;
class Emoji
{
    private static $emojiPattern = '%(?:
        \xF0[\x90-\xBF][\x80-\xBF]{2} # planes 1-3
        | [\xF1-\xF3][\x80-\xBF]{3} # planes 4-15
        | \xF4[\x80-\x8F][\x80-\xBF]{2} # plane 16
    )%xs';
 
    public static function encode($text)
    {
        return self::replace($text, function ($m) {
            return ":".bin2hex($m[0]).":";
        });
    }
 
    public static function decode($text)
    {
        return preg_replace_callback("/:([A-F0-9]{8}):/isu", function ($m)
        {
            $result = hex2bin($m[1]);
 
            if (preg_match(self::$emojiPattern, $result))
            {
                return $result;
            }
 
            return $m[0];
        }, $text);
    }

    public static function replace($text, $callback)
    {
        return preg_replace_callback(self::$emojiPattern, $callback, $text);
    }
 
    public static function getSaveModificator()
    {
        return array(
            array(__CLASS__, 'encode')
        );
    }
 
    public static function getFetchModificator()
    {
        return array(
            array(__CLASS__, 'decode')
        );
    }
}