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RE: UNS: RE: UNS: WCAG considering amending F65 to NOT fail missing ALT text if title or aria-label is present

From: David MacDonald <david100@sympatico.ca>
Date: Tue, 26 Nov 2013 06:09:24 -0500
Message-ID: <BLU0-SMTP3536839D0F5357F22B20D4FEEC0@phx.gbl>
To: "'Joshue O Connor'" <joshue.oconnor@cfit.ie>
CC: "'HTML Accessibility Task Force'" <public-html-a11y@w3.org>, "'WCAG WG'" <w3c-wai-gl@w3.org>, <kirsten@can-adapt.com>
There are several fixes, here are two:
1) use aria-describedby insread of aria-labelledby because it maps to the
accDescription, not the accName, so the alt gets the accName and the
describedby gets accDescription
2) leave off the aria-labelledby, so the user will hear the ALT text, and
encounter the supplementary text in the paragraph after the image.

If the algorithm does not shift from OR to AND, then we will need to
introduce WCAG failures for the presence of both ALT+aria-label, and
ALT+aria-labelledby in an image.

I think API's should concatenate ALL attributes competing for the accName.

Cheers,
David MacDonald

CanAdapt Solutions Inc.
Tel:  613.235.4902
http://ca.linkedin.com/in/davidmacdonald100
www.Can-Adapt.com
   
  Adapting the web to all users
            Including those with disabilities


-----Original Message-----
From: Joshue O Connor [mailto:joshue.oconnor@cfit.ie] 
Sent: November 26, 2013 5:52 AM
To: David MacDonald
Cc: 'HTML Accessibility Task Force'; 'WCAG WG'
Subject: Re: UNS: RE: UNS: WCAG considering amending F65 to NOT fail missing
ALT text if title or aria-label is present

[trimming cc list]

David MacDonald wrote:

> For a moment I will take off my "objectivity hat" and put forth my 
> major concern. An accessibility problem which I've seen in the wild 
> among developers who are beginning to learn about ARIA is they don't 
> understand that the computation of the accName in accessibility API's, 
> is an OR algorithm

Agreed, they don't know that - and why would they? This is very new to many.
Anything that we can do to help a developer understand the algorithms
hierarchy is a good thing. Many won't have any interest, they'll just want a
robust solution (at best), at worst something that they just don't have to
think about but will do.

>     - if aria-labelledby references one or more id elements in the page,
pass it to the accName OR
>      -if the aria-label attribute is present, pass it to the accName OR
>     -if the alt attribute is present, pass it to the accName OR
>     -if the title attribute is present, pass it to the accName
>
> So they do things like this:
> <img scr="eiffelTower.jpg" alt="Eiffel tower" labelledby="123"> <p 
> id="123">  The tower stands 324 metres (1,063 ft.) tall</p>
>
> In this example the screen reader user would not know that it is the
Eiffel tower because the ALT text is not read since the labelledby got to
the accName first. This is a crude example where many of us in this field
would easily know how to fix it.

I wouldn't make assumptions about that. Please mail us the fix as you see
it, or please add it to a relevant technique wiki page - nice 
teachable moment.	

Thanks

Josh
Received on Tuesday, 26 November 2013 11:09:58 UTC

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