Add target="_blank" to link with JavaScript

Question

I need to write a method that takes a String and parses it for links (a href). If it finds a link it should add target="_blank" to the link, if it is not already there.

Example: The Inputstring "

 <a href="www.google.com">Google</a> and <a href="www.yahoo.com"> target="_blank">Yahoo</a> are search engines

... should result in the output String

<a href="www.google.com" target="_blank">Google</a> and <a href="www.yahoo.com" target="_blank">Yahoo</a> are search engines

Any idea how to realize this?

Answer 1

Not very difficult with plain js.

var links = document.getElementsByTagName('a');
var len = links.length;

for(var i=0; i<len; i++)
{
   links[i].target = "_blank";
}

Answer 2

Fraught with problems but usable with plain JavaScript:

function addBlankTargets(s) {
  return (""+s).replace(/<a\s+href=/gi, '<a target="_blank" href=');
}

Or with jQuery:

function addBlankTargets(s) {
  var p = $('<p>' + s + '</p>');
  p.find('a').attr('target', '_blank');
  return p.html();
}
var s = '<a href="www.google.com">Google</a> and '
      + '<a href="www.yahoo.com">Yahoo</a> '
      + 'are search engines.';
var x = addBlankTargets(s);
x; // => '<a href="www.google.com" target="_blank">Google</a> and
   //     <a href="www.yahoo.com" target="_blank">Yahoo</a>
   //     are search engines.'