How to change target in hyperlink with regex

ajvdm

Hello,

I want to change links in a string, so only non-local websites will be opened in a new window.

I came up with the following:

$string = 'I want to open <a href="http://www.mydomain.com">this</a> in a new window. <a href="http://www.php.net">This</a> opens in the same window, and <a href="http://www.mydomain.com">the last one</a> opens in a new window.';
$string = preg_replace('/\href="(.*)"/', 'href="\\1" target="_blank"', $string);
echo $string;

First of all, this replaces only the last link in the string, and there is no difference between local or remote urls.

Then I had something like this:

function chklocal($matches) {
	if (stristr($matches[0], "www.mydomain.com")) {
		$retval = $matches[0];
	} else {
		$retval = $matches[0].' target="_blank"';
	}
	return $retval;
}
$string = preg_replace_callback('/\href="(.*)"/', 'chklocal', $string);
echo $string;

But this still doesn't work.

Can someone help me out?

Thanks...
Arjan

saraadmin

$string = preg_replace('/\href="(.*)"/', 'href="\\1" target="_blank"', $string);

this replaces only the last link in the string

Two things here:
1) You should add the global switch to your pattern flags (after the closing '/' of the pattern string, add a 'g').
2) "href="(.*)" is too greedy; it matches from the first '"' to the last '"'. Instead use a character class which matches any character except '"'.

'/href="([^\"]*)"/g'

preg_replace_callback may be the best way to solve this problem because you need to match "anything which comes between "href='" and "'" as long as its not a "'" or the string "www.mydomain.com"" which means that you need to negate a whole string. I only know how to negate character classes with regexps: [^a]

Sorry.