Re: HTML5: Table headers attribute should only reference a TH with id?

Hello Again, Sailesh:

Thank you for your email regarding table headers.

I believe the current HTML 5.0 specification should reflect the approach
mutually agreed between the WAI_PFWG and the HTML-WG during TPAC of
2008. Minutes of the PF discussion on this can be found at:

https://www.w3.org/2008/10/21-pf-minutes.html#item04

If the specification as currently published does not correctly reflect
our agreement, we can correct that in the 5.0 spec.

If no implementations work as specified, the language may be removed
to meet CR requirements.

In any case, further enhancement is most welcome, but will need to be
made against HTML 5.1. Would you please file a bug against HTML 5.1
noting your comments below as well as the NVDA bug you cite?

Thank you.

Janina

Sailesh Panchang writes:
> I see that HTML5 headers  attribute requires that the cells referenced  in it point to TH with id and not TD with id.
> I find this  strange and it sort of completely defeats the headers-id technique.
> The technique is meant to address really complex tables that  are irregular and complex  often for reasons beyond the author's control.
> So plain TH and scope are unlikely to make the table accessible.
> Here the headers-id method gives the power to associate  a cell that is marked up as TD and visually serves as a header cell as a header for benefit of non-sighted users.
> Is it really necessary to  put this constraint into the HTML5 standards?
> 
> See the Travel Expense Summary table in HTML 4.01 and the note in section11.4.2 that recognizes that  it is not always possible to mark  up a header cell as TH.
> Sure for some complex tables where it is possible to mark up all header cells as TH and assign it an id-value,  the rule has little impact because the author can certainly mark them up as TH.
> But where the author is constrained and cannot mark up a cell as TH and yet treat it as a header for other data cells, he will be at a loss. 
> Maybe  one can flag a soft validation error so that if authors have accidently omitted to mark up a cell as TH it will be brought to their notice.
> But it should not come in the way of accessibility.
> Today NVDA depends on Firefox to expose the DOM and  table headers and Firefox does not expose a TD with an id as a header even if the headers attribute for a data cell refers to it. 
> So please remove this constraint from the HTML specs.
> Please see and support
> Bug 881048 -Recognizing column headers marked up as TH in a table- improvement needed) – NVDA Community#3245(
> https://bugzilla.mozilla.org/show_bug.cgi?id=881048
> 
> Sailesh Panchang
> www.deque.com

-- 

Janina Sajka, Phone: +1.443.300.2200
   sip:janina@asterisk.rednote.net
  Email: janina@rednote.net

Linux Foundation Fellow
Executive Chair, Accessibility Workgroup: http://a11y.org

The World Wide Web Consortium (W3C), Web Accessibility Initiative (WAI)
Chair, Protocols & Formats http://www.w3.org/wai/pf
 Indie UI   http://www.w3.org/WAI/IndieUI/

Received on Friday, 21 June 2013 21:24:59 UTC