Posts Tagged ‘Web Standards’

ASP.NET and XHTML Validation

If you’ve ever created an XHTML 1.0 Strict page containing an ASP.NET form element and ran it through the W3 Validator, you’ve undoubtedly noticed it’s reported as being invalid no matter what you do and no matter how valid the code actually appears. This is because ASP.NET adjusts the way it renders markup according to the requesting user agent. ASP.NET pities the W3 Validator and sends it bad code. This can be fixed with a “browser” file. The file and instructions on its use are available from that page.

However, that’s not all. The validator will now see your pages the way you see them in your browser, but ASP.NET is still rendering an invalid name attribute on your form element! You need to add a line to the system.web section of your web.config file:

<xhtmlConformance mode="Strict" />

Now ASP.NET plays nice with the W3 Validator and renders a valid XHTML Strict form! Now you can stop using the XHTML Transitional doctype and start using the XHTML Strict doctype on your ASP.NET pages!

—Kyle Blizzard

The Target Attribute and Strict XHTML

So, you’ve decided to start creating your web sites with valid strict XHTML 1.0 and CSS. Your client wants a “links” page containing none other than links to other web sites. So you oblige and, to keep your client’s visitors on his site, you make the links open in a new window. So you throw in target="blank" and you’re done. Just run it through the W3 validator…

There is no attribute “target”? What gives?!

Yes, indeed, target is not a valid attribute in XHTML 1.0 Strict. There’s really only one way around it of which I’m aware, and that’s by using Javascript. My preferred method is as follows:

<a href="" onclick=", 'OffSite').focus(); return false;">

This opens the URL in a new window and brings it into focus if the user had previously opened an “OffSite” window and didn’t close it.

You would still put the desired URL in the href attribute just like with any hyperlink. That way, if the visitor for some reason has Javascript disabled, the link still functions correctly. It just wouldn’t open in a new window.

One caveat though—in Firefox 2 and later with default settings, this code causes the linked site to open in a new tab, not a new window. If you find this to be a problem, there is a way around it, and that’s by adding the window options parameter such as:

<a href="" onclick=", 'OffSite', 'directories=yes,location=yes,menubar=yes,resizable=yes,scrollbars=yes,toolbar=yes').focus(); return false;">

Those are all the options required to make the window appear normally with default tool and menu bars—kind of a pain. At this point, you may want to move the code into an external Javascript file. The function I use typically looks like the following:

function OpenOffSite(a)
{, "OffSite", "directories=yes,location=yes,menubar=yes,resizable=yes,scrollbars=yes,toolbar=yes").focus();
return false;

Then the onclick attribute of your anchor would look like so:

<a href="" onclick="return OpenOffSite(this);">

Your links now open in a new window! Welcome to the world of XHTML conformity. 🙂

—Kyle Blizzard