嵌入正则表达式的链接和图像

Question

SO Community!

I am new to regular expressions and I have a trouble with them. I have a chat script with simple parser of user data. There is an ability to embed an image with BBCode tag, like this: [img]http://example.com/image.png[/img]. I also want to do automatic link transformation to valid hyperlinks. I have two processing REGEXes, and I don't know how to solve the conflict between them.

To process [img] tag I use this and it executes first:

$line = preg_replace('/\[img\](https?:\/\/[a-zA-Z0-9%\-_?&=:+.\/]+)\[\/img\]/iU', '<a href="$1" target="_blank"><img class="incl_img" src="$1"></a>', $line, 5);

Then to process links I use this:

$line = preg_replace('#(https?:\/\/([a-zA-Z0-9-.]+)\/?[a-zA-Z0-9?&=.:\#\/\-_~%+]*)#e', '\'[<a href="$1" title="$1" target="_blank">$2</a>]\'',$line);

And when user posts an image the link processing regex breaks <img> tag by inserting its <a href=... instead of link. How to avoid it without using special [url] tag or something else? How to separate [img] tags from simple links? Any corrections of regexes and/or algorithms are welcome. Thanks in advance!

Answer 1

I solved my problem. The solution is to correct the second regex (URL parser) and add some conditions. New regex will look like this:

#(?<!src="|href=")(https?:\/\/([a-zA-Z0-9\-\.]+)\/?[a-zA-Z0-9?&=.:\#\/\-_~%+]*)#e'

And the whole code became this:

$line = preg_replace('#(?<!src="|href=")(https?:\/\/([a-zA-Z0-9\-\.]+)\/?[a-zA-Z0-9?&=.:\#\/\-_~%+]*)#e', '\'[<a href="$1" title="$1" target="_blank">$2</a>]\'',$line);