[whatwg] Early feedback on header association algorithm
Henri Sivonen
hsivonen at iki.fi
Sat Nov 22 05:50:21 PST 2008
On Oct 29, 2008, at 19:43, Aaron Leventhal wrote:
> 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."
While implementing a special lookup method is something that one would
want to avoid, using getElementById has two problems:
1) It makes the association brittle under copy and paste. Consider a
case where a page author creates a table with internal id references
and then a maintainer duplicates the table and edits the contents of
the copy table. Now the table coming later in the document order is
inaccessible but this brokenness is unobvious to a person who isn't
accessing the page with AT.
2) It makes the reporting of table relationships not form a coherent
table. Consider a program that instead of allowing the user to
traverse the table an arc at a time tries to pull all the arcs from
the accessibility API and reconstruct the table in its own process
space. If there are arcs between tables, the result is not a table
structure at all.
--
Henri Sivonen
hsivonen at iki.fi
http://hsivonen.iki.fi/
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