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Re: WAI-ARIA language providing for strong and weak implicit semantics from host language.

From: Al Gilman <Alfred.S.Gilman@ieee.org>
Date: Wed, 10 Dec 2008 11:11:32 -0500
Message-Id: <23CA7A96-0097-42CF-B8D6-C0952153C597@ieee.org>
Cc: W3C WAI-XTECH <wai-xtech@w3.org>, wai-xtech-request@w3.org
To: Aaron M Leventhal <aleventh@us.ibm.com>


On 10 Dec 2008, at 4:02 AM, Aaron M Leventhal wrote:

>
> The OS X accessibility protocol allows a subrole, which is a more  
> detailed role. This allows apps to expose a role that older  
> versions of VoiceOver would understand, and a newer more specific  
> subrole for later versions.
>
> Therefore, we probably shouldn't say that there can't be more than  
> one. Instead, I would explain when there could be no role, and in  
> those cases the UA should expose either a totally neutral role that  
> means no role, or not expose the object at all.

I think we have them covered.

Note that we agreed to defer role extension to the 2.0 version of  
ARIA.  So the
idea that there would be a browser that recognizes a precise role and  
an AT that
only recognizes its more general down-level super-role is a future  
thing.  OS X
has subroles now, but we don't have a need to feed them sub/super- 
role pairs yet.

An AT as of 1.0 is either going to recognize the sub-role or not  
recognize the super-role.

[I am going to call them the precise role and the general role from  
here on in in the
discussion, as they can be ancestor and descendant by generic/ 
specific and not merely
immediate next steps in the derivation graph.]

In the case of an up-level browser than knows about role extension  
and 2.0 roles with
a layered AT that only knows about the 1.0 roles, it is probably a  
better idea for the
browser to *compute the super-roles of the "applicable ARIA role"  
from the definition
of that role* rather than depend on what the author has done to put  
super-roles in the
list after the precise role.

Authors *should still* put down-level-recognizable super-roles in the  
list in the
@role attribute value to support down-level _browsers_, but the up- 
level browsers
should go from the dsub/super-relationships declared in the published  
definition of the precise
role to determine the chain of "precise role and down-level  
ancestors" to expose to
AT.

Note that in

</quote
cite="">
7.3.2.5. Applicable ARIA role rules, in accessibility API binding

The applicable ARIA role, if there is one, MUST be the role value  
which is mapped to the value of a role property in any accessibility  
API which accepts only one role value.
</quote>

s/which/that -- for U.S. English

APIs that allow subroles are exempted from using the "applicable ARIA  
role" and that value *only*.

We could add a note, something informative, on the order of:

Future versions of WAI-ARIA might define extension mechanisms by  
which sub-roles of specification-published
roles can be defined by publications other than versions of this  
specification.  In that case, APIs that
allow sub-roles in addition to roles would be well advised to do the  
following on encountering an extension
or later-published role that is a specialization of a down-level  
role: expose the down-level super-role as
'role' and the extended role as 'sub-role.'

On second thought, I think that we can broaden that if we move it to  
the Implementation Guidelines.  Where
we have the API capability to expose role and sub-role, the 'role'  
should expose a super-role of the
narrowest-applicable role in any case where the OS knows that there  
are ATs that only understand the
super-role and won't understand the sub-role.  That's not limited to  
ARIA situations.  They can expose
a multi-selectable tablist as sub-role='accordion' if the API defines  
an 'accordion' role.  That is for
the API binding implementation to handle and define.

[Editorial note:  I am consciously avoiding the plain-English use of  
'should' and 'may' in this informative
prose, as I think this is good editorial practice in a document that  
uses RFC-2119 terms in normative
provisions.]

Al


>
>
> - Aaron
>
>
> From: Al Gilman <Alfred.S.Gilman@ieee.org>
> To: Aaron M Leventhal/Cambridge/IBM@IBMUS
> Cc: W3C WAI-XTECH <wai-xtech@w3.org>, wai-xtech-request@w3.org
> Date: 12/10/2008 03:25 AM
> Subject: Re: WAI-ARIA language providing for strong and weak  
> implicit semantics from   host language.
>
>
>
>
>
>
> On 8 Dec 2008, at 6:56 AM, Aaron M Leventhal wrote:
>
> >
> > > I fear that no matter how we describe the two factors, given that
> > the
> > > explicit ARIA role can be present or absent and the implicit ARIA
> > role
> > > can be strong, weak, or absent, we still wind
> > > up with the same five cases in the bullet list in "7.3.2.2.
> > Overview."
> >
> > I think the bulleted list is a good start but should be simplified
> > by saying something like:
> > 1. If the native markup gives precedence to its own implicit
> > semantics, or there is no ARIA role, use the native markup to
> > determine the role (if the native markup does not provide a role,
> > do not expose one).
> > 2. Otherwise, use the ARIA role
>
> OK,
>
> In the latest cut it reads like
>
> <quote
> cite="http://lists.w3.org/Archives/Public/www-archive/2008Dec/
> att-0018/01-part#ua_role">
> Depending on the precedence assigned by the host language, the
> applicable ARIA role may come from the host language semantics, from
> the expicit ARIA role, or there man be none.  If there is no explicit
> ARIA role or the native markup takes precedence, use the native
> markup to determine the role.  Otherwise, use the explicit ARIA role.
> There may be one,  or there may be none, but not more than one.
> </quote>
>
> Al
>
> > - Aaron
> >
> >
> >
> > From: Al Gilman <Alfred.S.Gilman@ieee.org>
> > To: W3C WAI-XTECH <wai-xtech@w3.org>
> > Date: 12/05/2008 09:44 PM
> > Subject: Re: WAI-ARIA language providing for strong and weak
> > implicit semantics from  host language.
> >
> >
> >
> >
> >
> >
> > On 4 Dec 2008, at 5:32 AM, Aaron M Leventhal wrote:
> >
> > >
> > > Hi Al,
> > >
> > > I believe there is no need for the middle "weak" concept.
> > > We only need strong or no semantics. The semantically strong
> > > constructs are immune from ARIA.
> > >
> > > Also, for each construct specified, whether they have a default
> > > ARIA role or provide additional ARIA properties is an additional,
> > > separate decision.
> >
> > I agree with the logic.
> >
> > A. some language constructs have implicit properties
> > (including states and roles in properties, here) regardless whether
> > 'weak' or 'strong'
> >
> > B. some of these implicit properties are strong, i.e. take  
> precedence
> > over explicit ARIA markup.
> >
> > I'm not sure how  re-organizing things this way simplifies the WAI-
> > ARIA spec.  It's pretty much
> > how I addressed things.  But I have fiddled the prose to make it  
> read
> > more like this. The new
> > v.3 is at:
> >
> > http://lists.w3.org/Archives/Public/www-archive/2008Dec/att-0014/01-
> > part
> >
> > I fear that no matter how we describe the two factors, given that  
> the
> > explicit ARIA role can
> > be present or absent and the implicit ARIA role can be strong, weak,
> > or absent, we still wind
> > up with the same five cases in the bullet list in "7.3.2.2.
> > Overview."
> >
> > http://lists.w3.org/Archives/Public/www-archive/2008Dec/att-0014/01-
> > part#ua_role_overview
> >
> > > So, this document would ultimately be simplified into two groups:
> > > http://hsivonen.iki.fi/aria-html5-bis/
> > >
> > > FWIW, Henri Sivonen, the original author of the strong/weak/no
> > > concept, agreed that it's a good simplification.
> >
> >
> >
> > > - Aaron
> > >
> > >
> > > From: Al Gilman <Alfred.S.Gilman@ieee.org>
> > > To: W3C WAI-XTECH <wai-xtech@w3.org>
> > > Date: 12/04/2008 03:24 AM
> > > Subject: WAI-ARIA language providing for strong and weak implicit
> > > semantics from host language.
> > >
> > >
> > >
> > >
> > >
> > >
> > > Re:
> > > http://www.w3.org/WAI/PF/Group/track/issues/67
> > > http://lists.w3.org/Archives/Public/www-archive/2008Dec/ 
> att-0011/01-
> > > part
> > >
> > > This is a 'scratch draft' that is to say forked from the main
> > line of
> > > Editor's draft versions.  It is a strawman rewrite of 6.2 and  
> 7.3 to
> > > make room for host languages to provide built-in semantics
> > > that takes over from ARIA markup where appropriate.
> > >
> > > Please read over the draft and see if there is
> > >
> > > a) a simpler way to say it that is still correct.
> > > b) anything we missed.
> > >
> > > Al
> > >
> > >
> > >
> > >
> >
> >
> >
> >
>
>
>
>
Received on Wednesday, 10 December 2008 16:12:17 GMT

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