Going Postel
I wrote a little while back about my feelings on hash-bang URLs:
I feel so disappointed and sad when I see previously-robust URLs swapped out for the fragile #! fragment identifiers. I find it hard to articulate my sadness…
Fortunately, Mike Davies is more articulate than I. He’s written a detailed account of breaking the web with hash-bangs.
It would appear that hash-bang usage is on the rise, despite the fact that it was never intended as a long-term solution. Instead, the pattern (or anti-pattern) was intended as a last resort for crawling Ajax-obfuscated content:
So the #! URL syntax was especially geared for sites that got the fundamental web development best practices horribly wrong, and gave them a lifeline to getting their content seen by Googlebot.
Mike goes into detail on the Gawker outage that was a direct result of its “sites” being little more than single pages that require JavaScript to access anything.
I’m always surprised when I come across as site that deliberately chooses to make its content harder to access.
Though it may not seem like it at times, we’re actually in a pretty great position when it comes to front-end development on the web. As long as we use progressive enhancement, the front-end stack of HTML, CSS, and JavaScript is remarkably resilient. Remove JavaScript and some behavioural enhancements will no longer function, but everything will still be addressable and accessible. Remove CSS and your lovely visual design will evaporate, but your content will still be addressable and accessible. There aren’t many other platforms that can offer such a robust level of loose coupling.
This is no accident. The web stack is rooted in Postel’s law. If you serve an HTML document to a browser, and that document contains some tags or attributes that the browser doesn’t understand, the browser will simply ignore them and render the document as best it can. If you supply a style sheet that contains a selector or rule that the browser doesn’t recognise, it will simply pass it over and continue rendering.
In fact, the most brittle part of the stack is JavaScript. While it’s far looser and more forgiving than many other programming languages, it’s still a programming language and that means that a simple typo could potentially cause an entire script to fail in a browser.
That’s why I’m so surprised that any front-end engineer would knowingly choose to swap out a solid declarative foundation like HTML for a more brittle scripting language. Or, as Simon put it:
Gizmodo launches redesign, is no longer a website (try visiting with JS disabled): http://gizmodo.com/
Read Mike’s article, re-read this article on URL design and listen to what John Resig has to say in this interview .