- From: Joseph Scheuhammer <clown@alum.mit.edu>
- Date: Tue, 13 Jan 2015 13:06:32 -0500
- To: Alexander Surkov <surkov.alexander@gmail.com>, Dominic Mazzoni <dmazzoni@google.com>
- CC: Daniel Trebbien <dtrebbien@gmail.com>, W3C WAI Protocols & Formats <public-pfwg@w3.org>
On 2015-01-13 12:35 PM, Alexander Surkov wrote:
> Otherwise aria-setsize on list item is a rather weird thing imo.
The rationale is to handle large data sets where only some of the items
are loaded into the DOM, at a time. For example, the DOM may have only,
say, 20 items from somewhere from an actual set of, say 10, 000.
Something has to indicate which items (aria-posinset) are loaded, and
how big the set really is (aria-setsize):
" If all items in a set are present in the document structure, it is not
necessary to set this
attribute<http://w3c.github.io/aria/aria/aria.html#dfn-attribute>, as
the user agent can automatically calculate the set size and position for
each item. However, if only a portion of the set is present in the
document structure at a given moment, this
property<http://w3c.github.io/aria/aria/aria.html#dfn-property> is
needed to provide an explicit indication of an element's position."
(http://w3c.github.io/aria/aria/aria.html#aria-posinset)
There is a similar rationale for large grids -- the need to declare
which row (aria-rowindex) and which column (aria-colindex) a gridcell
belongs to when only part of the grid is loaded into the DOM.
--
;;;;joseph.
'Array(16).join("wat" - 1) + " Batman!"'
- G. Bernhardt -
Received on Tuesday, 13 January 2015 18:07:04 UTC