Re: ISSUE-95 hidden - Chairs Solicit Proposals

Maciej Stachowiak, Mon, 01 Feb 2010 00:28:39 -0800:
> On Feb 1, 2010, at 12:15 AM, Henri Sivonen wrote:
>> On Jan 29, 2010, at 17:49, Leif Halvard Silli wrote:

>> HTML5 "hidden" is mostly redundant with "aria-hidden". It provides 
>> three differences:
>> 1) "hidden" will eventually have UA style sheet support.

(1) What does style sheet support in regard to "hidden" mean? Will we 
be able to display the semantically hidden element despite that is 
hidden? (If displayed, then I would argue that it would not be 
semantically hidden anymore - except that it would remain hidden, of 
course, for them that rely on a non-visual user agent interpretation of 
the content - thus in many ways effectively becoming like aria-hidden.)

(2) It is  not clear to me how aria-hidden differs from hidden w.r.t. 
style sheet support - any attribute, including aria-hiddden, can be 
used for targeting the element via a style sheet.

>> 2) "hidden" in theory applies to non-accessibility unusual 
>> modalities while "aria-hidden", in theory, only matters to 
>> accessibility API mapping.

See above.

>> 3) "hidden" is part of the host language on the principle that ARIA 
>> is a transitional solution and should become syntactically obsolete 
>> as host languages gain enough features to address the use cases.

(1) Some in this group see ARIA as something that should "take over": 
E.g. we don't need @summary because we have this and that @aria- 

(2) Your point 2) makes it sound as if you see aria-hidden and hidden 
as same: we should need only one of them.

> Besides these functional differences, they also have different use 
> cases.


> In my experience advising teams at Apple on adding ARIA markup 
> to content, aria-hidden is most useful when you have content that you 
> *do* want visible in normal rendering, but not through accessibility 
> APIs.

If, as I think Henri hinted, this is possible:

	<p hidden style="display:block">Displayed, despite @hidden</p>

then everyone, except the blind, would be unaware of its hiddenness. 
Whereas this,

	<p aria-hidden style="display:block">Displayed</p>

would be much clearer: it is hidden only for a group.

If something is hidden from the AT users, then I would argue that it is 
never dangerous to also hide for the non-AT users. So, for the use case 
for @hidden mentioned in the draft (a login system which hides things 
until logged in), then it should be possible to hide the content for 
all, based on the presence of aria-hidden.

> Of course, there are likewise valid use cases for content that 
> is semantically hidden (not currently relevant) in all renderings.
> So in conclusion, I am not sure that "hidden" fully obsoletes 
> "aria-hidden". But it does have a valuable distinct use.

I have difficulty discern the two.
leif halvard silli

Received on Tuesday, 2 February 2010 14:59:33 UTC