有几种解决方案可以解决这个问题,但其中大多数都写得不好且不完整。在这种情况下,我建议使用大型框架之一的现有解决方案,无需重新发明轮子。
例如,这篇关于 Zenverse 的文章 http://zenverse.net/php-function-to-auto-convert-url-into-hyperlink/描述了方式WordPress http://www.wordpress.org/处理这个。
让我在此处添加片段以供进一步参考:
function _make_url_clickable_cb($matches) {
$ret = '';
$url = $matches[2];
if ( empty($url) )
return $matches[0];
// removed trailing [.,;:] from URL
if ( in_array(substr($url, -1), array('.', ',', ';', ':')) === true ) {
$ret = substr($url, -1);
$url = substr($url, 0, strlen($url)-1);
}
return $matches[1] . "<a href=\"$url\" rel=\"nofollow\">$url</a>" . $ret;
}
function _make_web_ftp_clickable_cb($matches) {
$ret = '';
$dest = $matches[2];
$dest = 'http://' . $dest;
if ( empty($dest) )
return $matches[0];
// removed trailing [,;:] from URL
if ( in_array(substr($dest, -1), array('.', ',', ';', ':')) === true ) {
$ret = substr($dest, -1);
$dest = substr($dest, 0, strlen($dest)-1);
}
return $matches[1] . "<a href=\"$dest\" rel=\"nofollow\">$dest</a>" . $ret;
}
function _make_email_clickable_cb($matches) {
$email = $matches[2] . '@' . $matches[3];
return $matches[1] . "<a href=\"mailto:$email\">$email</a>";
}
function make_clickable($ret) {
$ret = ' ' . $ret;
// in testing, using arrays here was found to be faster
$ret = preg_replace_callback('#([\s>])([\w]+?://[\w\\x80-\\xff\#$%&~/.\-;:=,?@\[\]+]*)#is', '_make_url_clickable_cb', $ret);
$ret = preg_replace_callback('#([\s>])((www|ftp)\.[\w\\x80-\\xff\#$%&~/.\-;:=,?@\[\]+]*)#is', '_make_web_ftp_clickable_cb', $ret);
$ret = preg_replace_callback('#([\s>])([.0-9a-z_+-]+)@(([0-9a-z-]+\.)+[0-9a-z]{2,})#i', '_make_email_clickable_cb', $ret);
// this one is not in an array because we need it to run last, for cleanup of accidental links within links
$ret = preg_replace("#(<a( [^>]+?>|>))<a [^>]+?>([^>]+?)</a></a>#i", "$1$3</a>", $ret);
$ret = trim($ret);
return $ret;
}
链接文章中所写的示例用法:
$string = 'I have some texts here and also links such as http://www.youtube.com , www.haha.com and [email protected] /cdn-cgi/l/email-protection. They are ready to be replaced.';
echo make_clickable($string);