Re: Comparison of Smart Headers and HTML5 (ACTION-85)

Here's a copy of the feedback I sent to the whatwg list. I'm  
especially interested in seeing #2 dealt with because then I can give  
much better feedback:

1. On this part:
         "If there is a header cell in the table <http:// 
www.whatwg.org/specs/web-apps/current-work/multipage/tabular- 
data.html#concept-table> whose corresponding |th <http:// 
www.whatwg.org/specs/web-apps/current-work/multipage/tabular- 
data.html#the-th-element>| element has an ID that is equal to the  
value of id, then assign the first such header cell in tree order to  
the data cell. "
I don't want to implement a special local table only  
getElementByIdInTable. I'd rather have this reworded to something like
"If there is an element in the document with a corresponding ID (via  
getElementById) equal to the value of /id/, and it is a header cell  
in the current table, then assign it to the data cell."

2. The larger part of algorithm is upside down for our needs. I see a  
use case for providing what headers are associated with a cell, but  
not the other way around. Typically an AT will want to know what  
labels or headers to present to a user when a user navigates to a  
cell. Therefore, I wish the entire algorithm was flipped and tells us  
what headers are a match for a given cell.

3. The one piece of information we do need when we are on a given  
<th> is whether to expose it with ROLE_ROWHEADER or ROLE_COLUMNHEADER  
in our GetRole() implementation. If scope isn't "row", "rowgroup",  
"col" or "colgroup" then we'll need to base that on the position in  
the table. It seems fairly obvious if the <th> is in an edge (but not  
corner) position, but other cases are less obvious.

I haven't gone through the algorithm in fine detail yet, mostly  
because of comment #2. We'd have to turn the algorithm inside out in  
order to evaluate it.

- Aaron





From:	"Ben Millard" <cerbera@projectcerbera.com>
To:	"Al Gilman" <Alfred.S.Gilman@IEEE.org>, "Michael\(tm\) Smith"  
<mike@w3.org>
Cc:	"HTMLWG" <public-html@w3.org>, "WAI Liason" <wai-liaison@w3.org>
Date:	12/01/2008 07:47 AM
Subject:	Comparison of Smart Headers and HTML5 (ACTION-85)





ACTION-85 has a page here:

<http://www.w3.org/html/wg/tracker/actions/85>

I have published my comparison of the 2 algorithms:

<http://projectcerbera.com/blog/2008/11/compare>

The advice for HTML5 (incomplete) is at the end:

<http://projectcerbera.com/blog/2008/11/compare#advice>

(The <p> after each <h3> summarises the advice I give for that design
choice. The subsequent bullet points summarise what led me to that
conclusion.)

Feedback is welcome and encouraged, especially if it's public. I will  
fix
mistakes in this document if they are reported publically or privately.
Including typos. :)

Ian Hickson has told me he plans to review table feedback in mid to late
December 2008. So I'd like feedback on this document to be sent my way
before then, if possible. Let's say 15th December 2008, as that's 2 full
weeks after my deadline to publish this.

Don't forget your Xmas shopping!

-- 
Ben Millard
<http://projectcerbera.com/web/study/>