php regular expression for external links

colm_c

I'm trying to do a regular expression to indentify external links and add an icon to them.

So far I've got:

[PHP]
$pattern = '/<a href="?(.*:\/\/)?([^ \/]*)([^ >"]*)"?[^>]>(.*)(<\/a>)/';
$replacement = '<a href="$1$2$3">$4 <img src="/images/icon_web.gif" alt="external link" /></a>';
$content = preg_replace($pattern, $replacement, $content, -1);
print $content;
[/PHP]

But it only seems to put the icon on the last link on the page.

Any help much appreciated.

forbairt

from the top of my head your match should have a ig or something added to it ... case insensitive and multiple times ...

the $pattern should possible have ig at the end

$pattern = '/<a href="?(.*:\/\/)?([^ \/]*)([^ >"]*)"?[^>]>(.*)(<\/a>)/ig'; 

edit: ah the -1 takes care of that .. sorry

Edit Edit: just ran your code and its working fine so I'm confused

colm_c

It doesn't seem to work with more than 1 link in the text.

Did you try it with a couple of links?

forbairt

colm_c wrote:

It doesn't seem to work with more than 1 link in the text.

Did you try it with a couple of links?

Code sample I ran ...

<?PHP

$content = <<<END
		<ul>
				<li><a href="http://us.ard.yahoo.com/SIG=12lgn363s/M=385895.10615157.11509033.7674020/D=yahoo_top/S=2716149:FPAD/_ylt=AjIVmKHx06EPO2i9ahEcDdf1cSkA/Y=YAHOO/EXP=1182346617/A=4545677/R=8/SIG=14ufch571/*http://shopping.yahoo.com/b:Diamond%20Buying%20Guide:784708673;_ylc=X3oDMTFsY2kzZGxyBF9TAzI3MTYxNDkEc2VjA2ZwLWhtYW50bGUEc2xrA2ZpbGxlcmFkLWFwcmlsLWRpYW1vbmRz">Diamond</a></li>
				<li><a href="http://us.ard.yahoo.com/SIG=12lgn363s/M=385895.10615157.11509033.7674020/D=yahoo_top/S=2716149:FPAD/_ylt=AjIVmKHx06EPO2i9ahEcDdf1cSkA/Y=YAHOO/EXP=1182346617/A=4545677/R=9/SIG=14ukb9290/*http://shopping.yahoo.com/b:Jewelry%20Buying%20Guide:784708697;_ylc=X3oDMTFrOGdrMjlpBF9TAzI3MTYxNDkEc2VjA2ZwLWhtYW50bGUEc2xrA2ZpbGxlcmFkLWFwcmlsLWpld2Vscnk-">Jewelry</a></li>
				<li><a href="http://us.ard.yahoo.com/SIG=12lgn363s/M=385895.10615157.11509033.7674020/D=yahoo_top/S=2716149:FPAD/_ylt=AjIVmKHx06EPO2i9ahEcDdf1cSkA/Y=YAHOO/EXP=1182346617/A=4545677/R=10/SIG=15544heiq/*http://shopping.yahoo.com/b:Engagement%20Buying%20Guide:784708681;_ylc=X3oDMTFua2tyYW82BF9TAzI3MTYxNDkEc2VjA2ZwLWhtYW50bGUEc2xrA2ZpbGxlcmFkLWFwcmlsLWVuZ2FnZW1lbnQ-">Engagement</a></li>
			</ul>
END;

$pattern = '/<a href="?(.*:\/\/)?([^ \/]*)([^ >"]*)"?[^>]>(.*)(<\/a>)/';
$replacement = '<a href="$1$2$3">$4 <img src="/images/icon_web.gif" alt="external link" /></a>';
$content = preg_replace($pattern, $replacement, $content, -1);
print $content;  

?>

Ph3n0m

sorry but why are you not using css to do this?

http://www.askthecssguy.com/2006/12/showing_hyperlink_cues_with_cs_1.html

colm_c

@forbairt: That didn't seem to work for me, I had to do an explode in the end and preg_match each of the items in the array.

@Ph3n0m: That CSS doesn't work in IE6, so it's really any good to me. I could also have just added a class to each external link, but this will work in IE6 but if the links wrap the icon doesn't go to the end of the link it goes to the end of the left most part of the link.

Like this:

This is text and this is <x>
a link

The icon would be where the <x> is

forbairt

a[href $='.pdf'] { 
   padding-right: 18px;
   background: transparent url(icon_pdf.gif) no-repeat center right;
}

you learn something new everyday ... always knew the [ type = ] for input boxes but didn't realise you could match to the end of a href

Ph3n0m

but as pointed out - it doesnt work on IE 6