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Re: [1.2T LC] should @role in SVG be animatable? (ISSUE-2076)

From: Al Gilman <Alfred.S.Gilman@ieee.org>
Date: Thu, 9 Oct 2008 21:29:48 -0400
Message-Id: <400AC09D-3DAC-4518-8BDE-441D4A67FFDA@ieee.org>
Cc: "w3c-wai-pf@w3.org PF" <w3c-wai-pf@w3.org>, www-svg <www-svg@w3.org>
To: Doug Schepers <schepers@w3.org>


On 9 Oct 2008, at 2:33 AM, Doug Schepers wrote:

>
> Hi, Al-
>
> Al Gilman wrote (on 9/28/08 9:01 PM):
>>
>> As regards WAI-ARIA alone, the answer should be 'no.'  In our best
>> practices we instruct script authors not to change the role of an
>> element, but rather to destroy the DOM object for that element and
>> create a new object with the new role.
>>
>> This is because the consumers of the accessibility APIs expect the  
>> role
>> of a node to be static, just as xml:lang is not animatable in SVG.
>>
>> SVG documents that animate the value of @role would confuse the AT
>> consumers of the accessibility APIs.  I suppose that the browser  
>> could
>> trap these
>> property-change events and destroy and create the object in the
>> accessible object graph, but then...
>
> I specified it as animatable because of its similarity to the 'class'
> attribute, which is also animatable.  We added this attribute in large
> part to work with ARIA, but as indicated in the XHTML Role Attribute
> Module, and also in our spec, it is intended for general processing as
> well, not just for ARIA.
>
> Note that this (like most attributes) can be changed via the DOM, as
> well, so there is no guarantee that the value will remain immutable
> through the life of the document.
>
> I do think it's reasonable to impose this restriction on the role
> attribute when used with WAI-ARIA.  My initial reaction, though, is  
> that
> this is a restriction that should be placed on the attribute by the
> WAI-ARIA spec, not by SVG.  I don't think that there is any  
> conflict in
> doing so.

I think it would be better to do this in the SVG module implementing
WAI-ARIA.  Not to confuse the WAI-ARIA spec reader with the extra
concept of 'animatable' that they won't encounter until SVG.

But regardless of which of these does this, or the ARIA Best Practices,
we / I can live with SVG leaving this animatable as of SVG 1.2T.

> There may be other uses of @role that would be made easier by allowing
> it to be animated, and which might not affect AT UAs at all (that  
> is, it
> may not change the ARIA roles, but some other role value).
>
>
>> Can anybody come up with a use case for animating the @role value  
>> using
>> the currently-defined roles from either the XHTML Role Module or  
>> WAI-ARIA?
>
> Personally, my philosophy is that specs should not impose undue
> restrictions on authors, such that innovation is stifled.  This is  
> both
> a blessing and a curse, I realize, but it is impossible for the  
> authors
> of specs to anticipate and dictate every use for a Web language.
>
> In conclusion, I would prefer not to change the spec in this instance.
> If this doesn't satisfy your comment, we can revisit it, but if you're
> okay with this, please do let us know promptly.

Not a show-stopper.  It's OK.

Al

> Regards-
> -Doug
>
Received on Friday, 10 October 2008 01:30:36 GMT

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