Latte\Runtime\Filters::escapeHtmlAttrUnquoted PHP Метод

    public static function escapeHtmlAttrUnquoted($s)
    {
        $s = (string) $s;
        return preg_match('#^[a-z0-9:-]+$#i', $s) ? $s : '"' . self::escapeHtmlAttr($s) . '"';
    }