[RESOLVED] Need a function which strips tags without removing URLs

lpa

In my forum script I use a function which makes Urls and email addresses clickable. For example:

http://www.phpbuilder.com/board/newthread.php?do=newthread&f=2

changes to:

<a style="color:#49541C;" href="http://www.phpbuilder.com/board
/newthread.php?do=newthread&f=2" target="new">http://www.phpbuilder.com
/board/n...ead&f=2</a>

Everything works fine, but the problem is to edit forum texts. Is there any way how to convert such a link back to:

http://www.phpbuilder.com/board/newthread.php?do=newthread&f=2

Thanks.

sohguanh

Regular expression has always been the hard-to-perfect skills for me personally. I have built some sample code below but it is not perfect so use it with care!

Basically it cannot match nested <a> tags. If you want to match sequential <a> tags within a string, use preg_match_all. And also it cannot match Unicode characters.

<a...> ... <a...> ... </a> </a> // cannot match nested tags

<a...> ... </a> <a...> ... </a> //sequential open/end tags use preg_match_all

<?php

$input = '<a style="color:#49541C;" href="http://www.phpbuilder.com/board/newthread.php?do=newthread&f=2" target="new">http://www.phpbuilder.com/board/n...ead&f=2</a>';

$pattern='#<\w*a.*?>(.*?)<\w*/\w*a\w*>#i';

preg_match($pattern,$input,$matches);

print_r($matches);
?>

I look forward for some expert PHP developers to improve on my regular expression code above.

Thanks.

lpa

sohguanh, thank you for your reply. Actually, this is not what I want. This produces:

Array ( [0] => http://www.phpbuilder.com/board/n...ead&f=2  [1] => http://www.phpbuilder.com/board/n...ead&f=2 )

I want to remove anything, just leaving link which is located <a href="here">. If I wanted to keep the link which is located between >here</a> I could use strip_tags function. The link between < and </a> is shortened to prevent design distortion with long links.

sohguanh

lpa;10947106 wrote:
I want to remove anything, just leaving link which is located <a href="here">. If I wanted to keep the link which is located between >here</a> I could use strip_tags function. The link between < and </a> is shortened to prevent design distortion with long links.

Ok got what you want. You can replace the $pattern to below.

Previous version mistook \w with \s. Correct is \s.

$pattern='#<\sa.+?href\s=\s"(.?)".?>.?<\s/\sa\s*>#i';

Above enforce the check to really make sure <a..> ... </a>, that is a tag has an ending tag before extract the href information.

$pattern='#<\sa.+?href\s=\s"(.?)".*?>#i'

Above will run faster but it does not really check <a> has an ending tag and just extract the href information.

Please also note since I uses preg_match, the second element is what you want instead of the first element.

Extract from PHP.net
If matches is provided, then it is filled with the results of search. $matches[0] will contain the text that matched the full pattern, $matches[1] will have the text that matched the first captured parenthesized subpattern, and so on.

Thanks.

lpa

thank you.