W3C home > Mailing lists > Public > public-html-a11y@w3.org > March 2012

RE: Drop longdesc, get aria-describedat?

From: Leif Halvard Silli <xn--mlform-iua@xn--mlform-iua.no>
Date: Thu, 8 Mar 2012 05:54:48 +0100
To: John Foliot <john@foliot.ca>
Cc: Geoff Freed <geoff_freed@wgbh.org>, Judy Brewer <jbrewer@w3.org>, Silvia Pfeiffer <silviapfeiffer1@gmail.com>, Richard Schwerdtfeger <schwer@us.ibm.com>, W3C WAI-XTECH <wai-xtech@w3.org>, HTML Accessibility Task Force <public-html-a11y@w3.org>
Message-ID: <20120308055448273876.5d877e0c@xn--mlform-iua.no>
John Foliot, Wed, 07 Mar 2012 22:22:44 -0500:
> Quoting Leif Halvard Silli:
>> Geoff Freed, Thu, 8 Mar 2012 01:21:45 +0000:
>>  Which in turns means that -
>> in the end - @longdesc's burial is being prepared.
> I think, inadvertently, you've hit on one of the problems - the 
> headlong rush to burial, without a long and useful retirement, or 
> even retirement plan in place.

One could argue that there is a plan - at least a thought - in the ARIA 
community. One could further argue, that that plan/thought implies the 
burial ...

> Let's frame it this way: for all intents and purposes, aria-label and 
> @alt both produce an accessible name for an image. Given that, should 
> we obsolete @alt? Of course not! (Yet according to the pure logic of 
> the argument, we could) One reason of course is that we have yet to 
> do the right amount of education, we don't yet have enough 
> user-agents to ensure that this is "universal" (or at least as 
> universal as @alt is), etc. It is no different here.

I would add that @alt is also directly useful for e.g. text browser 
users or if you disable image display - user agents are not tuned to 
render @aria-label, should we have replaced @alt with @aria-label. 
Also, @alt is much more successful. 

But you are right: In theory one could replace @alt. It is only because 
@alt is so *well* integrated into the language that we don't do 
something like that.

Or, just consider the fate of @summmary ... ?

>>  <div><style scope>div{color:red}</style></div>
>> One could argue that it should not be conforming, yet, because <style
>> scope> has zero implementation, so far. In fact, if you look in
>> public-html - in this moment, then you'll see that it isn't even clear
>> how it will work ...  the CSS cascade is unclear:
>> http://www.w3.org/mid/4F570227.8060707@mit.edu
> Leif, as I outlined in my earlier email, the trials and tribulations 
> of scoping rules for color and CSS pale against any requirement for 
> persons with disabilities. I am sympathetic to their problems, but 
> for lynx users, and screen reader users, color scoping is, shall we 
> say, not important. Access to information is.


>> So we do not necessarily need so *much* before we can put in HTML5 ...
>> At the same time: It would be futile, in an directly accessibility
>> related issue, to recommend people to use an attribute with zero
>> implementation. And hence, yet another argument in favor of saying that
>> the validity of @longdesc should depend on duplication with the
>> @aria-describedAT attribute.
> They should have a similar, perhaps identical implementation. but we 
> need to de-link them from the discussion at this time: HTML5 is 
> HTML5, and ARIA is ARIA, and one specification/standard should not be 
> dictating a timeline to the other IMHO.

I don't think they need to be absolutely equal: Think about the @name 
attribute on the anchor element. It lives - 'mentally' - in the same 
namespace as @id - yes HTMl4 uses 'namespace' about it. But they are 
different nodes. And so getElementById() will not match @name. 
Likewise, @longdesc can work a little bit different from 
@aria-describedAT. The important thing, though, is that when both are 
present, then an AT that supports both, should ignore one of them -  
normally it should ignore the @longdesc.

Certainly, I would be fine with @longdesc fully conforming. I just try 
to 'dress it up' so that it can be more acceptable to those that don't 
necessarily agree ...

So yes, they must be delinked, functionally. But the condition for 
using @longdesc, could nevertheless be that @aria-describedAT is also 

I don't think this is a 'golden egg'. I just try to show how one can 
reason if we have plan to replace it with @aria-describedAT.
Leif H Silli
Received on Thursday, 8 March 2012 04:55:24 UTC

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