Fwd: Re: Effect of role=presentation on img elements with svg

(Resending, because I forgot to include  w3c-wai-pf@w3.org and 

Richard Schwerdtfeger, Fri, 28 Feb 2014 07:57:17 -0600:
> Leif, 
> It is meant to mean any SVG element. Why would we have an SVG mapping 
> guide for one element?

If the message is that there is no difference, then *that* should be 
the guidance.

The reason that it is - it seems to me - built into the very logic of 
the <img> element that, unless the author has filled the @alt attribute 
with content, then users have not direct access to whatever the <img> 
element displays. If this is indeed different for <img> when it 
contains a <svg>, then it is worth pointing out.

Authors’ perceptions might be colored by the fact that the <img> has 
the requirement to use the alt="", also when @src contains a SVG. And 
authors are used - and told - to treat the alt="" attribute as if it is 
the sole access to the image, for non-visual users. 

For <iframe src=svg>, it might also be worth pointing out. However, 
since authors are used to linking to markup documents (namely html) via 
<iframe>, it it does not come as the same surprise that the SVG of 
<iframe src=svg /> can be accessed directly.

For <object data=svg>, on the other hand, then I think authors may 
easily have more or less the same expectations as for <img>.

May be for the next generation of web authors, this won’t be necessary 
pointing out … :-) (I suspect will soon start with glasses.) But IMO, 
it is worth it, for the time being.

(Feel free to reply on public-pfwg@, according to your previous 

Leif Halvard Silli

> Leif Halvard Silli ---02/03/2014 05:03:05 PM---Richard Schwerdtfeger, 
> Sun, 2 Feb 2014 14:01:09 -0600: > While I understand what Apple has 
> implement
> From: Leif Halvard Silli <xn--mlform-iua@xn--mlform-iua.no>
> To: Richard Schwerdtfeger/Austin/IBM@IBMUS
> Cc: Steve Faulkner <faulkner.steve@gmail.com>, James Craig 
> <jcraig@apple.com>, Joanmarie Diggs <jdiggs@igalia.com>, Cynthia 
> Shelly <cyns@microsoft.com>, Bryan Garaventa 
> <bryan.garaventa@whatsock.com>, "T.V Raman" <raman@google.com>, 
> "jongund@illinois.edu" <jongund@illinois.edu>, "jason@jasonjgw.net" 
> <jason@jasonjgw.net>, "wai-xtech@w3.org" <wai-xtech@w3.org>, 
> "w3c-wai-pf@w3.org WAI-PFWG" <w3c-wai-pf@w3.org>
> Date: 02/03/2014 05:03 PM
> Subject: Re: Effect of role=presentation on img elements with svg
> Richard Schwerdtfeger, Sun, 2 Feb 2014 14:01:09 -0600:
>> While I understand what Apple has implemented (defaults to a group 
> role) we
>> have not decided on a normative mapping for SVG across browsers.  We will
>> be creating an implementation guide for SVG. Here are the current outline
>> drafts:
>> www.w3.org/WAI/PF/wiki/Outline_Core_User_Agent_Implementation_Guide
> The ”SVG 2.0 User Agent Implementation Guide” section speaks about the 
> ”SVG element”. It does not speak about the IMG element or any other 
> elements via which SVG can be served.
>> At the last WAI-PF face to face in Toronto we agreed to develop these 3
>> specs. I have to do to get with Joseph Scheuhammer to do some further
>> planning for this. We will be developing a core implementation guide for
>> 1.1 to which the HTML5 and SVG specs. will refer to. Both SVG and HTML5
>> will have different name computation mechanisms that we need to agree on.
>> Each host platform has different features that will contribute to the name
>> computation.
>> Both HTML5 and SVG will require different name computation algorithms.
>> Also, I would encourage us to post comments to the new public-pfwg@w3.org.
>> We no longer need xtexh and wai-pf (which is private) .
> OK. Interesting.
> Leif Halvard Silli
>> Rich
>> Rich Schwerdtfeger
>> From: Leif Halvard Silli <xn--mlform-iua@xn--mlform-iua.no>
>> To: Steve Faulkner <faulkner.steve@gmail.com>
>> Cc: James Craig <jcraig@apple.com>, Joanmarie Diggs
>>             <jdiggs@igalia.com>, Cynthia Shelly 
> <cyns@microsoft.com>, Bryan
>>             Garaventa <bryan.garaventa@whatsock.com>, "T.V Raman"
>>             <raman@google.com>, "jongund@illinois.edu"
>>             <jongund@illinois.edu>, "jason@jasonjgw.net"
>>             <jason@jasonjgw.net>, "wai-xtech@w3.org" <wai-xtech@w3.org>,
>>             "w3c-wai-pf@w3.org WAI-PFWG" <w3c-wai-pf@w3.org>
>> Date: 02/02/2014 10:23 AM
>> Subject: Re: Effect of role=presentation on img elements with svg
>> Steve Faulkner, Sun, 2 Feb 2014 15:09:44 +0000:
>>> https://dl.dropboxusercontent.com/u/377471/SVG/index.html

>> Based on Safari 6 and VoiceOver for OSX 10.7, the conclusions for the
>> SVG-via-img-element test are incorrect w.r.t. Safari+VoiceOver. See the
>> test:
>> https://dl.dropboxusercontent.com/u/377471/SVG/adobesvgtest4.html

>> The claim, at that page, is that the <img> defaults to img role.
>> However, it actually is given group role.  Of course, for OSX 10.8 and
>> 10.9, the Accesibility Inspector might show another result. It is a
>> quite serious deviation from HTML5 to let <img> default to group role
>> rather than img role … So may be it is fixed ...
>> Note as well that the SVG image contains script, but that HTML5 says
>> about <img>: ”However, these definitions preclude SVG files with
>> script”.
>> Anyway: The most interesting thing, here, is what, if anything - in
>> ARIA - permits AT to look into the document referenced at @src for
>> deciding the alternative text. And why is <svg> unique? After all, it
>> is possible to embed meta data in other images as well.
>> No doubt, this matter will confuse authors even more w.r.t. to the
>> effect of role="presentation". But that said, is not more complicated
>> than this: We need to decided if/how/where the document in src="svg"
>> fits into the accessible name calculation. I would say, though, it
>> would be a fundamental break with today’s ARIA.
>> It is a little annoying that we are invited to a debate about the name
>> of the presentation role. And then it ends up as debate about meaning
>> of the presentation role/pushing its limits ...
>> Leif Halvard Silli
>>> has a range of tests, also see
> http://blog.paciellogroup.com/2013/12/using-aria-enhance-svg-accessibility/

>>> --
>>> Regards
>>> SteveF
>>> HTML 5.1 <http://www.w3.org/html/wg/drafts/html/master/>
>>> On 2 February 2014 13:26, Leif Halvard Silli <
>>> xn--mlform-iua@xn--mlform-iua.no> wrote:
>>>> Steve Faulkner, Sun, 2 Feb 2014 08:23:20 +0000:
>>>>>> Effectively, what you are saying above, is that this:
>>>>>>    <img role="presentation" src="svg">
>>>>>  the subdom of an <svg> img is available:
>> https://dl.dropboxusercontent.com/u/377471/SVG/adobesimplesvgtest1.htmlfor
>>>>> an example,
>>>>> the subdom of <img src=svg> does not appear to be available:
>>>>> https://dl.dropboxusercontent.com/u/377471/SVG/adobesvgtest4.html

>>>> I am preparing some test page.
>>>> Tou are perhaps more after deeper things rather than VoiceOver
>>>> behavior.  But an interesting expansion of your own tests could be to
>>>> set the role of the directly emebedded <svg> element to "img" and see
>>>> if that changes anything in VoiceOver.
>>>> Leif Halvard Silli

Received on Monday, 3 March 2014 18:35:23 UTC