CODEWITHSUNDEEP
regexactionscriptflex4
Harmjan
Harmjan

Reputation: 132

Regex for URL to hyperlink

At the moment, I have the following regex for replacing a URL to a HTML hyperlink:

msg = msg.replace(/(\b((https?|ftp|file):\/\/|www.)[-A-Z0-9+&@#\/%?=~_|!:,.;]*[-A-Z0-9+&@#\/%=~_|])/gi, "<a href='out.php?u=$1'>$1</a>");

This replaces 

http://www.stackoverflow.com

into 

<a href='out.php?u=http://www.stackoverflow.com'>http://www.stackoverflow.com</a>

But now I have a problem. When I already have a hyperlink, I don't want to replace the URL inside that hyperlink to a new hyperlink.

So:

<a href='http://www.stackoverflow.com'>Stackoverflow</a>

must not become:

<a href='<a href='out.php?u=http://www.stackoverflow.com'>http://www.stackoverflow.com</a>'>Stackoverflow</a>

Does somebody know how I can prevent this?

Upvotes: 1

Views: 333

Answers (2)

Harmjan
Harmjan

Reputation: 132

I've already fixed it by adding a white space before and after the string, and replaces all URLs with a whitespace before and after:

msg = " " + msg + " ";
msg = msg.replace(/(\s)(((https?|ftp|file):\/\/|www.)[-A-Z0-9+&@#\/%?=~_|!:,.;]*[-A-Z0-9+&@#\/%=~_|])(\s)/gi, " <a target='_blank' href=\"" + websiteUrl + "/out.php?u=$2\"><font color='" + hyperlinkColor + "'>$2</font></a> ");
msg = StringUtil.trim(msg);

This doesn't replace all the hyperlinks, because a hyperlink doesn't have whitespaces before and after the URL.

Upvotes: 2

Elroy Flynn
Elroy Flynn

Reputation: 3218

You can do that with a negative look-ahead assert, written as (?!expression). So...

?!(\<a)/(\b((https?|ftp|file):\/\/|www.)[-A-Z0-9+&@#\/%?=~_|!:,.;]*[-A-Z0-9+&@#\/%=~_|])/gi, "<a href='out.php?u=$1'>$1</a>");

Upvotes: 1

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