/**
* @param $s
* @param int $normalization_form
* @param string $leading_combining
*
* @return array|bool|mixed|string
*/
public static function filterString($s, $normalization_form = 4, $leading_combining = '◌')
{
if (false !== strpos($s, "\r")) {
// Workaround https://bugs.php.net/65732
$s = str_replace(array("\r\n", "\r"), "\n", $s);
}
if (preg_match('/[\\x80-\\xFF]/', $s)) {
if (Normalizer::isNormalized($s, $normalization_form)) {
$n = '-';
} else {
$n = Normalizer::normalize($s, $normalization_form);
if (isset($n[0])) {
$s = $n;
} else {
$s = UTF8::encode('UTF-8', $s);
}
}
if ($s[0] >= "€" && isset($n[0], $leading_combining[0]) && preg_match('/^\\p{Mn}/u', $s)) {
// Prevent leading combining chars
// for NFC-safe concatenations.
$s = $leading_combining . $s;
}
}
return $s;
}
