La seguente funzione permette di creare una url partendo da una stringa testuale, oltre a modificare i caratteri speciali, converte i singoli spazi e le lettere maiuscole, restituisce una stringa "ripulita" il piu possibile SEO friendly.
function sanifica($string) {
$string = strtolower($string);
$string = strip_tags($string);
$string = preg_replace("#\x{00a0}#siu", ' ', $string);
$string = str_replace(array_map('chr', range(0, 31)), '', $string);
$chars = array("?", "[", "]", "/", "\\", "=", "<", ">", ":", ";", ",", "'", "\"", "&", "’", "%20","+", "$", "#", "*", "(", ")", "|", "~", "`", "!", "{", "}", "%", "+", "^", );
$string = str_replace($chars, '-', $string);
$string = preg_replace('/[\r\n\t -]+/', '-', $string);
$convert = array('Þ' => 'TH', 'þ' => 'th', 'Ð' => 'DH', 'ð' => 'dh', 'ß' => 'ss','Œ' => 'OE', 'œ' => 'oe', 'Æ' => 'AE', 'æ' => 'ae', 'µ' => 'u');
$string = strtr($string, $convert);
$string = html_entity_decode( $string, ENT_QUOTES, "utf-8" );
$string = htmlentities($string, ENT_QUOTES, "utf-8");
$string = preg_replace("/(&)([a-z])([a-z]+;)/i", '$2', $string);
$string = preg_replace('/_+/', '-', $string);
$string = preg_replace(array('/ +/', '/-+/'), '-', $string);
$string = preg_replace(array('/-*\.-*/', '/\.{2,}/'), '.', $string);
$string = trim($string, '.-_');
return $string;
}
