Comments on: An important lesson learned about AJAX and accessibility http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-ajax-and-accessibility/ Web development and Internet trends Fri, 05 Dec 2008 09:51:03 +0000 http://wordpress.org/?v=2.6.1 By: Why inline CSS and JavaScript code is such a bad thing - Robert’s talk - Web development and Internet trends http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-ajax-and-accessibility/#comment-477426 Why inline CSS and JavaScript code is such a bad thing - Robert’s talk - Web development and Internet trends Thu, 20 Nov 2008 20:54:14 +0000 http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-axaj-and-accessibility/#comment-477426 [...] Company proxy servers filtering out code (for example, read An important lesson learned about AJAX and accessibility). [...] [...] Company proxy servers filtering out code (for example, read An important lesson learned about AJAX and accessibility). [...]

]]> By: Learning the World » Accessible Drop-Down Menus http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-ajax-and-accessibility/#comment-370039 Learning the World » Accessible Drop-Down Menus Mon, 11 Aug 2008 08:06:17 +0000 http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-axaj-and-accessibility/#comment-370039 [...] mobile devices often have problems with JavaScript or with layers. Some proxies in large companies filter JavaScript for security reasons, so you can’t rely on the ubiquitous availability, your script has to be [...] [...] mobile devices often have problems with JavaScript or with layers. Some proxies in large companies filter JavaScript for security reasons, so you can’t rely on the ubiquitous availability, your script has to be [...]

]]> By: How to hide and show initial content, depending on whether JavaScript support is available - Robert’s talk - Web development and Internet trends http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-ajax-and-accessibility/#comment-272685 How to hide and show initial content, depending on whether JavaScript support is available - Robert’s talk - Web development and Internet trends Tue, 13 May 2008 22:17:01 +0000 http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-axaj-and-accessibility/#comment-272685 [...] tells you if JavaScript is enabled or not in the web browser; not if it actually works. There are proxy servers out there cleaning out JavaScript files with what it thinks is inappropriate content, over-zealous antivirus programs, firewalls preventing [...] [...] tells you if JavaScript is enabled or not in the web browser; not if it actually works. There are proxy servers out there cleaning out JavaScript files with what it thinks is inappropriate content, over-zealous antivirus programs, firewalls preventing [...]

]]> By: FACTA ET VERBA » recursos y mas recursos AJAX http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-ajax-and-accessibility/#comment-6004 FACTA ET VERBA » recursos y mas recursos AJAX Fri, 14 Jul 2006 14:09:15 +0000 http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-axaj-and-accessibility/#comment-6004 [...] ne of a ticker script automatically, while the user is trying to read other content? Nope. [...] [...] ne of a ticker script automatically, while the user is trying to read other content? Nope. [...]

]]> By: Robert Nyman http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-ajax-and-accessibility/#comment-4393 Robert Nyman Thu, 27 Apr 2006 08:37:20 +0000 http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-axaj-and-accessibility/#comment-4393 Markus, Not sure, actually... And unfortunately I don't have any good environment to test. I like the creative thinking, though! :-) It just might work! Hakan, Well, that might be an alternative fallback option, but , like you say, then we miss out on some functionality. Markus,

Not sure, actually…
And unfortunately I don’t have any good environment to test. I like the creative thinking, though! :-)
It just might work!

Hakan,

Well, that might be an alternative fallback option, but , like you say, then we miss out on some functionality.

]]> By: Hakan Bilgin http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-ajax-and-accessibility/#comment-4387 Hakan Bilgin Thu, 27 Apr 2006 03:05:31 +0000 http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-axaj-and-accessibility/#comment-4387 This is rather old news yet topical; XML islands. Dean Edwards has recently wrote something about this. <a href="http://dean.edwards.name/weblog/2006/04/easy-xml/" rel="nofollow">XML Islands</a> But with XML islands, it's not possible to utilize the POST-method... /hbi This is rather old news yet topical; XML islands.

Dean Edwards has recently wrote something about this.
XML Islands

But with XML islands, it’s not possible to utilize the POST-method…

/hbi

]]> By: Markus Dresch http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-ajax-and-accessibility/#comment-4372 Markus Dresch Wed, 26 Apr 2006 17:48:19 +0000 http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-axaj-and-accessibility/#comment-4372 what about eval("new Active" + "X" + "Object(...)")? what about eval(”new Active” + “X” + “Object(…)”)?

]]> By: Robert Nyman http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-ajax-and-accessibility/#comment-4350 Robert Nyman Wed, 26 Apr 2006 14:05:26 +0000 http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-axaj-and-accessibility/#comment-4350 Jeena, Ha ha. :-) Tanny, I haven't tried it out, but I guess that might work. Not sure, though... Jakob, Yes, that's the kind of approach that needs to be done. Jeena,

Ha ha. :-)

Tanny,

I haven’t tried it out, but I guess that might work. Not sure, though…

Jakob,

Yes, that’s the kind of approach that needs to be done.

]]> By: Jakob Heuser http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-ajax-and-accessibility/#comment-4332 Jakob Heuser Wed, 26 Apr 2006 08:39:33 +0000 http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-axaj-and-accessibility/#comment-4332 Having looked at this before, we've used a very (cheap) load notifier which was placed at the end of each externally loaded js file: <code> filename = "myfile.js"; if (typeof ld_scripts != 'object') ld_scripts = new Object(); ld_scripts[filename] = true; </code> Upon the included file being loaded, you can always check ld_scripts and make sure everything you need filewise has made it intact. In our case, we were using it to ensure that all scripts loaded via document.write() had actually completed before we tried to reference objects and classes in those external files. Having looked at this before, we’ve used a very (cheap) load notifier which was placed at the end of each externally loaded js file:

filename = "myfile.js";
if (typeof ld_scripts != 'object') ld_scripts = new Object();
ld_scripts[filename] = true;

Upon the included file being loaded, you can always check ld_scripts and make sure everything you need filewise has made it intact.

In our case, we were using it to ensure that all scripts loaded via document.write() had actually completed before we tried to reference objects and classes in those external files.

]]> By: Tanny O'Haley http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-ajax-and-accessibility/#comment-4315 Tanny O'Haley Tue, 25 Apr 2006 17:27:05 +0000 http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-axaj-and-accessibility/#comment-4315 Instead of using ActiveX to initiate the xmlhttprequest object for Microsoft, how about trying the proprietary xml element? Instead of using ActiveX to initiate the xmlhttprequest object for Microsoft, how about trying the proprietary XML element?

]]> By: Jeena Paradies http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-ajax-and-accessibility/#comment-4310 Jeena Paradies Tue, 25 Apr 2006 16:26:54 +0000 http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-axaj-and-accessibility/#comment-4310 Oh that's cool, I just set up my proxy to filter all files including the text <code>javascript</code> ;-) Oh that’s cool, I just set up my proxy to filter all files including the text javascript ;-)

]]> By: Robert Nyman http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-ajax-and-accessibility/#comment-4308 Robert Nyman Tue, 25 Apr 2006 15:59:18 +0000 http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-axaj-and-accessibility/#comment-4308 Faruk, Yes, isn't it great? :-) Montoya, <blockquote>I’m finding it hard to see how an application could be implemented with unobtrusive AJAX and still be infinitely-scalable.</blockquote> I guess it depends on the application. Not every application can offer a perfect matching fallback with JavaScript, but as far as possible, it's a good goal to have. Jules, <blockquote>Or, don’t bother with JS because it is just too complicated.</blockquote> No, no, no. :-) JavaScript is amazing when used right (and in the absence of terrible proxy filters... :-)). Faruk,

Yes, isn’t it great? :-)

Montoya,

I’m finding it hard to see how an application could be implemented with unobtrusive AJAX and still be infinitely-scalable.

I guess it depends on the application. Not every application can offer a perfect matching fallback with JavaScript, but as far as possible, it’s a good goal to have.

Jules,

Or, don’t bother with JS because it is just too complicated.

No, no, no. :-)
JavaScript is amazing when used right (and in the absence of terrible proxy filters… :-)).

]]> By: Jules http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-ajax-and-accessibility/#comment-4303 Jules Tue, 25 Apr 2006 13:46:14 +0000 http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-axaj-and-accessibility/#comment-4303 Interesting! Therefore, to ensure that your site/application works, you must test all JS-capable browsers, older JS browsers (to verify graceful degradation), current but JS-disabled browsers, and current JS-enabled browsers with empty JS-files. Or, don't bother with JS because it is just too complicated. :-) Interesting!

Therefore, to ensure that your site/application works, you must test all JS-capable browsers, older JS browsers (to verify graceful degradation), current but JS-disabled browsers, and current JS-enabled browsers with empty JS-files.

Or, don’t bother with JS because it is just too complicated. :-)

]]> By: Montoya http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-ajax-and-accessibility/#comment-4301 Montoya Tue, 25 Apr 2006 13:32:38 +0000 http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-axaj-and-accessibility/#comment-4301 Fortunately I've been able to make my latest project with Progressive Enhancement... but doing this is very difficult. I'm finding it hard to see how an application could be implemented with unobtrusive AJAX and still be infinitely-scalable. Maybe I'm just not experienced enough to see it. Fortunately I’ve been able to make my latest project with Progressive Enhancement… but doing this is very difficult. I’m finding it hard to see how an application could be implemented with unobtrusive AJAX and still be infinitely-scalable. Maybe I’m just not experienced enough to see it.

]]> By: Faruk Ates http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-ajax-and-accessibility/#comment-4289 Faruk Ates Tue, 25 Apr 2006 12:31:09 +0000 http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-axaj-and-accessibility/#comment-4289 Ah, the wonderful hell that is clueless or violent proxy filtering. Ah, the wonderful hell that is clueless or violent proxy filtering.

]]> By: Robert Nyman http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-ajax-and-accessibility/#comment-4286 Robert Nyman Tue, 25 Apr 2006 12:04:54 +0000 http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-axaj-and-accessibility/#comment-4286 Marco, My thoughts have been similar to yours... To have some kind of variable or so that's initially false, but it gets set to true in the JavaScript file that contains the AJAX functionality. I guess it's good practice then to separate the <code>XMLHttpRequest</code> code into its own file, as not to ruin any other scripts in the web page. Chris, No, you understood me correctly, and it's a valid question. My gut feeling is the approach mentioned above, to separate AJAX functionality into its own file, and to maybe also use varibles to set and check if they exist to make sure everything will work as intended. Also, when possible, to have a proper fallback if the necessary JavaScript support isn't there. Marco,

My thoughts have been similar to yours…

To have some kind of variable or so that’s initially false, but it gets set to true in the JavaScript file that contains the AJAX functionality.

I guess it’s good practice then to separate the XMLHttpRequest code into its own file, as not to ruin any other scripts in the web page.

Chris,

No, you understood me correctly, and it’s a valid question.
My gut feeling is the approach mentioned above, to separate AJAX functionality into its own file, and to maybe also use varibles to set and check if they exist to make sure everything will work as intended.

Also, when possible, to have a proper fallback if the necessary JavaScript support isn’t there.

]]> By: Chris http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-ajax-and-accessibility/#comment-4285 Chris Tue, 25 Apr 2006 12:04:45 +0000 http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-axaj-and-accessibility/#comment-4285 But what can you do in fact against such problems? I mean, you can't foresee how a client machine or network filters your Javascript. Therefore you'll have to wait and react when an error occurs. Or did I just misunderstood? But what can you do in fact against such problems? I mean, you can’t foresee how a client machine or network filters your Javascript. Therefore you’ll have to wait and react when an error occurs.

Or did I just misunderstood?

]]> By: Marco http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-ajax-and-accessibility/#comment-4283 Marco Tue, 25 Apr 2006 10:49:21 +0000 http://www.robertnyman.com/2006/04/25/an-important-lesson-learned-about-axaj-and-accessibility/#comment-4283 Hmm... this is an interesting issue indeed. It introduces a lot of problems on pure AJAX applications that for whatever reason don't allow a non-JS version. A good example is a <a href="http://www.backbase.com/" rel="nofollow">BackBase</a> powered pure AJAX web application. I've seen those break horribly because of filtering proxies as well. Like you said, the noscript stuff won't work either because JS is actually enabled on the client. I guess it may be worthwhile to look for a way to detect whether a filtering proxy is present or not, possibly by a piece of JS that won't get filtered out which detects the lack of certain other code.... Just thinking out loud here... :) Hmm… this is an interesting issue indeed. It introduces a lot of problems on pure AJAX applications that for whatever reason don’t allow a non-JS version. A good example is a BackBase powered pure AJAX web application.

I’ve seen those break horribly because of filtering proxies as well. Like you said, the noscript stuff won’t work either because JS is actually enabled on the client.

I guess it may be worthwhile to look for a way to detect whether a filtering proxy is present or not, possibly by a piece of JS that won’t get filtered out which detects the lack of certain other code….

Just thinking out loud here… :)

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