An important lesson learned about AJAX and accessibility

Yesterday I went to visit some fellow consultants at their assignment for a sub company/department of one of Sweden’s largest banks. We had a talk about AJAX in general and different ways of how to implement it, and one of them opened his web browser to navigate to some AJAX-based web sites.

Something interesting followed next that really baffled me. Most web sites he went to had empty white patches where no content showed up, and some web pages even went completely blank. We knew for sure that JavaScript was enabled in his web browser of choice (IE, but still almost a real web browser… ;-)) so that couldn’t be the problem.

Then, naturally, we had to go test my ASK script to see what was going on. The version that we got there was the fallback version that works without JavaScript, but instead with regular links reloading the entire web page, meaning that no JavaScript events were applied.

After some digging, we found out that the JavaScript file was completely blank! The reason for this, apparently, is that the proxy server they had to go through to access internet totally cleansed any JavaScript file that contained this text:


	new ActiveXObject

So much for object detection and every other approach we recommend to web developers. Not a single line of code was left behind in the file. And the problem is that it won’t throw an error or show the content of a noscript tag either; everything just stops working.

My initial reaction was that if they have such a tight security environment doing that, I really don’t want to care to cater to them. But as my boiling blood got calmer (kind of an exaggeration), I realized that this company was too big to ignore the fact that all their users got shut out.

Also, if they have a situation like this, it’s likely that many other large companies have a similar solution.

Conclusion: if you want to develop AJAX apps, make sure that it works without JavaScript as well, apply all the scripts in an unobtrusive fashion. I’m just glad that ASK passed the test with its accessible groundwork and then building AJAX functionality on top of that (Actually, the Google Analytics code of the ASK page did in fact throw an error when we tested it, but I think it was just a consequence of the proxy server doing it’s job…).

Posted in Developing,JavaScript,Technology |

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