Forwarding to HTML A11Y TF per Chaals's suggestion.
Thanks,
AWK
Andrew Kirkpatrick
Group Product Manager, Accessibility
Adobe Systems
akirkpat@adobe.com
http://twitter.com/awkawk
http://blogs.adobe.com/accessibility
-----Original Message-----
From: Charles McCathie Nevile [mailto:chaals@yandex-team.ru]
Sent: Thursday, August 22, 2013 6:00 AM
To: Andrew Kirkpatrick
Subject: Re: longdesc extension question
Hi Andrew
(this is a good question, and I would love to have it in public - feel free to forward my response...)
On Wed, 21 Aug 2013 00:57:54 +0500, Andrew Kirkpatrick <akirkpat@adobe.com> wrote:
> Hi Chaals,
> I'm looking at the longdesc extension and also a couple of the WCAG
> techniques and have a question. It seems that a key problem with the
> implementations of longdesc today (well, at least JAWS and NVDA) is
> that when you activate the longdesc feature for an image they load the
> page with the longdesc and start reading at the required place. As
> some people are advocating for same-page references or many longdesc
> descriptions on a single separate page this is a problem because JAWS
> and NVDA don't know where the longdesc stops, just where it starts. As
> a result, a user listening to the longdesc for all three images in the
> following example would hear information about "a" once, "b" twice,
> and "c" three times.
>
> So the question is: Is there anything in the spec that requires that
> user agents read only the content contained within the HTML object
> with the matching id reference?
No, but there is a "should" requirement on authors:
'Authors should put descriptions within an element which is the target of a fragment link (e.g. longdesc="example.html#description") if a description is only part of the target document.'
which is intended to allow for such behaviour.
In general the spec tries to go lightly on requirements for user agents - it was somewhat controversial to require that they actually make the longdesc available to users in the first place ;(
cheers
Chaals
> Sample.html
> <img alt="a" longdesc="descs.html#a">
> <img alt="b" longdesc="descs.html#b">
> <img alt="c" longdesc="descs.html#c">
>
> Descs.html
> <div id="a"><p>This is my longdesc for a</p></div> <div id="b"><p>This
> is my longdesc for b</p></div> <div id="c"><p>This is my longdesc for
> c</p></div>
>
> Thanks,
> AWK
>
> Andrew Kirkpatrick
> Group Product Manager, Accessibility
> Adobe Systems
>
> akirkpat@adobe.com<mailto:akirkpatrick@adobe.com>
> http://twitter.com/awkawk
> http://blogs.adobe.com/accessibility
>
--
Charles McCathie Nevile - Consultant (web standards) CTO Office, Yandex
chaals@yandex-team.ru Find more at http://yandex.com