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Re: Please clarify ARIA definition of "grid" role

From: Maciej Stachowiak <mjs@apple.com>
Date: Tue, 07 Sep 2010 12:00:25 -0700
Cc: Richard Schwerdtfeger <schwer@us.ibm.com>, Steve Faulkner <sfaulkner@paciellogroup.com>, public-pfwg-comments@w3.org
Message-id: <44CB5304-6493-4050-97FD-BDA71E2ED8DC@apple.com>
To: James Craig <jcraig@apple.com>

On Aug 31, 2010, at 8:08 PM, James Craig wrote:

>>> 
>>> This still isn't right. The BaseConcept of grid is "HTML table", and the Required Owned Elements for grid are:
>>> 	• row
>>> 	• rowgroup → row
>>> 
>>> Last November at the F2F, we added the rowgroup role specifically so that ARIA grids could have role symmetry with the HTML table child elements thead, tbody, and tfoot. 
>>> 
>>> 	rowgroup http://www.w3.org/WAI/PF/aria/complete#rowgroup
>>> 	BaseConcept: HTML thead, tfoot, and tbody	
>>> 	Note: This role does not differentiate between types of row groups (e.g. thead vs. tbody), but an issue has been raised for WAI-ARIA 2.0.
>>> 
>>> One of the reasons we needed role symmetry was due to the complexities of presentation inheritance with host language implicit semantics.
>>> 
>>> From the spec: http://www.w3.org/WAI/PF/aria/complete#presentation
>> 
>> Would this imply that the "grid" definition *should* cover non-interactive presentations of tabular data, such as HTML <table>?
> 
> That's my understanding, but it's obvious we have some differing opinions in the group. We'll need to discuss this in a Working Group call before we can answer definitively.
> 
>> That is fine by me. I just want the ARIA spec and the HTML5 spec to be in sync on this.
> 
> Agreed. Thanks.
> 
>> The thing I didn't like about Rich's proposal is that it would make HTML <table> be a "grid but not really". I don't think that is a useful state. Either it's a grid or it's not.
>> 
>> I have no personal stake in the question of whether it is actually a grid. I just want it to be one or the other.


Ian mentioned in the bug that the "grid" role mentions "HTML table" as the "Base Concept", and that he took this to mean that an HTML table *is* a grid.

He also mentions that the rowgroup role description says: "The rowgroup role establishes a relationship between owned row elements. It is a structural equivalent to the thead,tfoot, and tbody elements in an HTML table element."

These things really make it seem like <table> is encompassed in what "grid" covers.

At this point, I think ARIA needs to be updated to make this issue crystal clear one way or the other.

I am personally leaning to making "grid" apply even to non-interactive tables. From the point of view of an assistive technology, I suspect the issues in presenting and navigating a table vs a grid are quite similar; it seems to me that it's the tabular presentation that is essential, not whether there are keybindings to move between cells. Furthermore, a definition that depends on specifically *keyboard* navigability is problematic because it is not device-independent. Touchscreen devices with no keyboard (such as Apple's iOS family of devices) are increasingly popular, and iOS in particular offers strong accessibility support. In the touchscreen paradigm, there is no such thing as a keyboard navigable grid; everything is done through direct manipulation, whether it is meant to be "interactive" or not.

Ultimately, though, this is a matter for PFWG to decide. I think it's important to have a clear decision on this and update the ARIA spec to match, so that HTML5 can be brought in sync.

Regards,
Maciej
Received on Tuesday, 7 September 2010 19:00:59 GMT

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