php emoji表情处理

/**
 * 表情转换  更新到ios9.2涵盖编码范围
 * @param $str
 * @return mixed
 */
public static function emoji_to_html($str) {
    $regex = '/([0-9|#][x{20E3}])|[x{00ae}|x{00a9}|x{203C}|x{2047}|x{2048}|x{2049}|x{3030}|x{303D}|x{2139}|x{2122}|x{3297}|x{3299}][x{FE00}-x{FEFF}]?|[x{2190}-x{21FF}][x{FE00}-x{FEFF}]?|[x{2300}-x{23FF}][x{FE00}-x{FEFF}]?|[x{2460}-x{24FF}][x{FE00}-x{FEFF}]?|[x{25A0}-x{25FF}][x{FE00}-x{FEFF}]?|[x{2600}-x{27BF}][x{FE00}-x{FEFF}]?|[x{2900}-x{297F}][x{FE00}-x{FEFF}]?|[x{2B00}-x{2BF0}][x{FE00}-x{FEFF}]?|[x{1F000}-x{1F6FF}][x{FE00}-x{FEFF}]?|[x{1F900}-x{1F9FF}][x{FE00}-x{FEFF}]?/u';
    $str = preg_replace_callback($regex,function($matches){
        $str = json_encode($matches[0]);
        $str = '<em data-emoji=' . str_replace('u', 'em:', $str) . '></em>';
        return $str;
    },$str);
    return $str;
}
从数据库取出后再转回
$string = preg_replace_callback('/<em data-emoji="(.*?)"></em>/is', "self::preg_emoji", $string);
/**
 * 输出emoji表情
 * @param $matches
 * @return mixed
 */
public static function preg_emoji($matches)
{
    $str = $matches[0];
    $str = str_replace('em:', 'u', $str);
    return $str;
}

/**
 * 过滤表情
 * @param $str
 * @return mixed
 */
public static function filter_emoji($str) {
    $regex = '/(\u[ed][0-9a-f]{3})/i';
    $str = json_encode($str);
    $str = preg_replace($regex, '', $str);
    return json_decode($str);
}