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Targetting Frames in XHTML

July 12, 2003

Update March 13, 2008: I used this technique on an older version of this website. I'm no longer using it because I think it's friendlier to let the user decide where windows should open. - Marty

This isn't so much an article as it is a tip. I'm writing this as I finish converting the Martian Software website to XHTML 1.1. The previous incarnation of this site (HTML 4.0 Transitional) relied upon the target attribute of the <a> tag to use a new frame for links outside the site, and to consistently reuse the same frame for all javadoc links. It worked great.

Once I switched to XHTML, however, I quickly found that target is no longer a built-in attribute for <a> tags. It could be done with some DTD gymnastics, but that seemed a ridiculous amount of effort just to retain some simple functionality. Then I found this article by Kevin Yank which provided a pretty clever method: mark the links you want to launch in a new window using the rel attribute, and massage the DOM with a little javascript. I won't repeat the reasoning here (it's a good article - go read it), but I think it's a great solution that, although it relies upon javascript, degrades quite gracefully.

It didn't totally fit my needs, however. I wanted to re-use frames as well rather than keep launching new windows. So I made a couple of tweaks:

  • To launch in a new window, set rel="external" for the link.
  • To launch in a specific frame, set rel="external:framename" for the link, where framename is the name of the targetted frame.

It works great, and it's used everywhere on this website. The modified script is included below.

function externalLinks() { if (!document.getElementsByTagName) return; var anchors = document.getElementsByTagName("a"); for (var i=0; i<anchors.length; i++) { var anchor = anchors[i]; if (anchor.getAttribute("href") && anchor.getAttribute("rel")) { var rel = anchor.getAttribute("rel"); if (rel == "external") { = "_blank"; } else if (rel.substring(0,9) == "external:") { = rel.substring(9, rel.length); } } } } window.onload = externalLinks;