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Re: Issue 204 CP objections [Was: TF Teleconference Minutes for 26 April]

From: Leif Halvard Silli <xn--mlform-iua@xn--mlform-iua.no>
Date: Fri, 27 Apr 2012 03:01:17 +0200
To: Benjamin Hawkes-Lewis <bhawkeslewis@googlemail.com>
Cc: HTML Accessibility Task Force <public-html-a11y@w3.org>, John Foliot <john@foliot.ca>
Message-ID: <20120427030117149933.2c21826c@xn--mlform-iua.no>
Benjamin Hawkes-Lewis, Thu, 26 Apr 2012 22:33:40 +0100:
> On Thu, Apr 26, 2012 at 5:06 PM, Janina Sajka <janina@rednote.net> wrote:
>>   janina: wonderful statement in there is that this can already 
>> happen and people are already doing to

> But it's also plausible that such authors might use @hidden with the
> intent of hiding elements even from accessible names and descriptions.
> For example, @aria-describedby might reference text that has the
> @hidden attribute until it is relevant to the state of the
> application, for example error text. Consider the following example
> 
>   <label for=username>Username:</label>
>   <input id=username name=username aria-describedby=error>
>   <div hidden id=error>Invalid username. Must be six or more
>                        alphanumeric characters.</div>
> 
> If "hidden" means never ever render the content, then the error
> message doesn't get included in accessible description calculation
> until the error occurs and the "hidden" attribute removed.
> 
> If "hidden" means do not render the content except for ARIA name and
> description calculation, then the error message is inappropriately
> included regardless of the actual state of the application.

To make the above not work, one must change ARIA so that 
aria-describedBY="section-where-aria-hidden-is-set-to-true"
does not work.

One could of course try to help by flagging it as an error to make 
aria-describedby point to @hidden and @aria-hidden="true" sections.

However, ARIA *also* says that one MUST do
<p style="display:none" aria-hidden="true">Hidden text.</p>

And thus, that one must not simply do
<p style="display:none">Hidden text.</p>

And so I guess you see the problem: To forbid to point hidden sections, 
could cause authors to not use aria-hidden="true".

> I've certainly seen lots of author confusion about whether display:
> none should hide or show content to screen readers.

Which underlines the problem I stated above.

> Maybe Jonas's scenario is more likely, I don't know. It would be good
> to have some data around this.
> 
>>   JF: I asked Ben before to give us the actual quotes from the specs 
>> that he says we are contradicting
>> 
>>   <janina> mike: See he's clearly saying "it violates the spec," but 
>> doesn't tell us where/how
> 
> I already sent an email responding to John's previous request for
> detail that explains at length why I think the text in the CP
> contradicts the HTML and ARIA specifications:
> 
> http://lists.w3.org/Archives/Public/public-html-a11y/2012Apr/0166.html


I read. And, whether pointing with a href link to a hidden section 
results in unpredictable behavior or predictably leads to a unexpected 
behavior, is not _that_ important. However, I get what you mean. I 
don't disagree in fixing it. That said, the use of @hidden does lead to 
some undpredictability too: The element could be made visible, via CSS, 
despite the @hidden attribute. What happens then?

When I read the rest of that letter, the I came to think that it 
perhaps should be forbidden to do 
aria-describedby=hidden-anchor-element. 
-- 
Leif H Silli
Received on Friday, 27 April 2012 01:01:51 GMT

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