How to replace plain URLs with links?

Question

I am using the function below to match URLs inside a given text and replace them for HTML links. The regular expression is working great, but currently I am only replacing t

Answer 1

Thanks, this was very helpful. I also wanted something that would link things that looked like a URL -- as a basic requirement, it'd link something like www.yahoo.com, even if the http:// protocol prefix was not present. So basically, if "www." is present, it'll link it and assume it's http://. I also wanted emails to turn into mailto: links. EXAMPLE: www.yahoo.com would be converted to www.yahoo.com

Here's the code I ended up with (combination of code from this page and other stuff I found online, and other stuff I did on my own):

function Linkify(inputText) {
    //URLs starting with http://, https://, or ftp://
    var replacePattern1 = /(\b(https?|ftp):\/\/[-A-Z0-9+&@#\/%?=~_|!:,.;]*[-A-Z0-9+&@#\/%=~_|])/gim;
    var replacedText = inputText.replace(replacePattern1, '$1');

    //URLs starting with www. (without // before it, or it'd re-link the ones done above)
    var replacePattern2 = /(^|[^\/])(www\.[\S]+(\b|$))/gim;
    var replacedText = replacedText.replace(replacePattern2, '$1$2');

    //Change email addresses to mailto:: links
    var replacePattern3 = /(\w+@[a-zA-Z_]+?\.[a-zA-Z]{2,6})/gim;
    var replacedText = replacedText.replace(replacePattern3, '$1');

    return replacedText
}

In the 2nd replace, the (^|[^/]) part is only replacing www.whatever.com if it's not already prefixed by // -- to avoid double-linking if a URL was already linked in the first replace. Also, it's possible that www.whatever.com might be at the beginning of the string, which is the first "or" condition in that part of the regex.

This could be integrated as a jQuery plugin as Jesse P illustrated above -- but I specifically wanted a regular function that wasn't acting on an existing DOM element, because I'm taking text I have and then adding it to the DOM, and I want the text to be "linkified" before I add it, so I pass the text through this function. Works great.