xhtml
Sun., Mar. 12, 2006, 9:03 am
There are many misconceptions about using XHTML for web pages and a huge debate is going on right now in the developer community about whether it should be used at all for web sites - given the lack of support in the current browsers.
Yes, I know that the current trend is to use XHTML, with CMS and some developer applications - but as many of you have discovered - this seldom works as advertised.
I jumped on the XHTML bandwagon all most as fast as the W3C finalized the specifications, but like a so many others, it took me a long time to discover all the facts about using it, and now have gone back to using only HTML 4.01 Strict for sites I work on.
I do think that XHTML is a better route for learning HTML markup since it is stricter than HTML, but as far as actually using it on web site - it may not be a good idea.
Here are some really important points to consider if you go the XHTML route:
1. Being standards compliant and/or using CSS does not require using XHTML. Properly marked up and valid HTML/CSS is standards compliant. CSS was developed to go hand-in-hand with HTML 4 - XHTML came later. It is surprising how many people think that to use CSS you must use XHTML.
2. Although XHTML 1.0 looks like HTML 4.01 it is not the same thing. XHTML is a "reformulation of HTML as XML" and is designed to be used by XML parsers. All markup must be well-formed and valid or the page will not be rendered at all by a XML compliant browser, when the page is served with the correct MIME type of application/xhtml+xml. HTML pages are served with the MIME type of text/html by default.
3. Although XHTML may be served as text/html for "backward compatibility" when you do this, you are actually sending the browser invalid HTML! The emply elements like "<br />", "<img ... />" are not valid HTML and rely on the browsers error correction to display properly. If all browsers actually following the HTML specs, they would be spitting out ">" characters all over your pages!
4. The most used (and buggiest) graphical web browser "Internet Exploder" does not understand XHTML at all (even the forth-coming Version 7 will not) when the page is served with the correct MIME type of application/xhtml+xml. IE will attempt to download the page rather than display it. You can see a demonstration of this by using this link: XHTML test page (http://www.hfrhost.com/%7Eevasser/test.xhtml). After attempting to view the page in IE, try it with Firefox or Opera (the only Windows browsers that do support XHTML). When XHTML pages are served as text/html, IE simply reads the page as invalid HTML and does its error correction.
5. Some CSS displays differently in XHTML than in HTML and some elements are handled differently. That's why some folks mention that pages marked up with CSS sometimes look a little different in XHTML than in HTML. Also some JavaScript functions like document.write() will not work in properly served XHMTL.
6. Finally, you should also be aware that XHTML 1.0/XHTML 1.1 are not forward compatible with the proposed XHTML 2! XHTML 2 will be a horse of a different color that does away with many existing elements such as <img> and there will no longer be <h1>,<h2>,etc. elements but only an <h> element; to mention just a few changes. No need to worry about that now - if the spec is finialized, it will be years before there are browsers that will be able to read it.
There are many other "gotchas" that pertain to using XHTML (properly) and I won't go into them here, but I wanted to add my two cents worth to this discussion, by pointing out some of them.
My personal recommendation (and that of many of the so-called HTML Guru's) is to use HTML 4.01 Strict but use XHTML coding style (what I like to call HTML+) thus:
All element tags and attributes in lower-case)
Close all elements such as <p></p> <li></li>, etc. NOTE: This doesn't mean using " />" on empty elements such as <br>).
Quote all attributes such as <img width="100" height="50" alt="">.
Include alt attributes on all images and don't use deprecated or none existant elements (such as <embed> - see the HTML 4.01 (http://www.w3.org/TR/html4/) specs).
Be sure all your ampersands are encoded properly "&" and not just "&"
And most important - use the correct <!DOCTYPE> (Strict not Transitional or Heaven forbid - Frameset) and be sure your pages and CSS are valid!
Ultimately, it's up to you, the web coder, which route you want to take XHTML or HTML. As it stands right now, there is no advantage what so ever to serving your web pages as XHTML, but it does no harm either, if served as text/html.
I'll be surprised if I don't get a lot of comments on this post!