Re: ARIA setsize attribute

From what I understand, aria-setsize is intended to fix dom structures where the set size can't be determined automatically from the DOM, e.g. a tree widget that is marked up as a flat html table and every row has a role of treeitem. In this case case the treeitems are not grouped by branch in the DOM structure, so you would need to apply aria-setsize aria-posinset to and aria-level  to every treeitem to fix this lack of structure. 

Wouldn't setting aria-setsize on a container be a bit pointless, because:
If the container truly represents the set, then you wouldn't need the aria-setsize attribute anymore because the setsize can be determined from the DOM structure. If it can't be (for example because certain child roles are not DOM children of the container) then aria-owns should be used and the user agent should add it to the automatically calculated set size.
If the container does not reflect the actual set (as in my tree example above), then aria-setsize wouldn't be applicable on this node.

Unless I'm missing something?

Regards,

Hans Hillen
TPG Europe





On Dec 12, 2009, at 2:29 PM, Alexander Surkov wrote:

> Hi.
> 
> The ARIA specification says "This property is marked on the members of
> a set, not the container element that collects the members of the set.
> " (see http://www.w3.org/WAI/PF/aria/states_and_properties#aria-setsize).
> However the same time it provides an example where the aria-setsize is
> used on the container element:
> 
> <ul role="listbox" aria-setsize="16" aria-labelledby="label_fruit">
>  <li role="option" aria-posinset="1"> apples </li>
> 
> I find the idea to define aria-setsize on the container element
> reasonable and useful and I would happy if the user agents would take
> into account the aria-setsize on the container only. But I'm fine with
> either way because currently aria-setsize is supposed to be used on
> the item.
> 
> Can the spec be fixed?
> 
> Thank you.
> Alex.
>