Re: Alternative to @aria-describedAT: <a role=img>

Alexander Surkov, Mon, 9 Apr 2012 11:51:48 +0900:

> <a role=img href> is a real edge case and it doesn't sound a good ARIA
> use case. See 
> http://www.w3.org/WAI/PF/aria-implementation/#mapping_conflicts

> "WAI-ARIA roles, states, and properties are intended to add semantic
> information when native host language elements with these semantics
> are not available, and are generally used on elements that have no
> native semantics of their own."

Question: Are you sure that <a role=img href> is something HTML has - 
without role=img? (See below.)

> Also look at:
> "user agents MUST use the semantic of the WAI-ARIA role for
> processing, not the native semantic, unless the role requires WAI-ARIA
> states and properties whose attributes are explicitly forbidden on the
> native element by the host language"

So what this text says is, that in the case of <a role=img href>, then 
there is no "MUST use the semantic of the WAI-ARIA role". Why is there 
no MUST? Answer: Because HTML5 - currently - explicitly disallows 
role="img" for the <a> element.

> <a role="img" href> is not described case but the most interesting
> part that ARIA doesn't require to ignore the native semantics blindly.

Yes, it *does* require to ignore the native semantics "blindly" (as in 
"MUST), *if* the host language permits it. HTML5 already permits the 
following roles for the <a> element:

Role must be either link, button, checkbox, menuitem, menuitemcheckbox, 
menuitemradio, tab, or treeitem.

See: http://www.w3.org/TR/html5/wai-aria.html#table-aria-weak


Also note that HTML5 says: "In addition, any element may be given the 
presentation role, regardless of the restrictions below."

> It sounds reasonable with me if ARIA would add or extend native
> semantics rather than completely remove it. From the user/web author
> point of view I don't see any benefits that AT users see an image but
> sighted users see a normal link.

HTML5 already disagrees with you: It allows role=presentation on both 
<a> and <img>. Also, when a link wraps around an image, then sighted 
users don't see "a normal link" — they see an image. Only when they 
hover around - or click - the image, do they see the link. 

Example: Om CNN.com today, each news story is presented like this:

<div><a href="LinkURL"><img src="URL" alt=""></a>
<a href="LinkURL">Veteran reporter Wallace remembered</a></div>

Question: Why - in your opinion - do the AT user need to perceive the 
first link above as a link? Already today, HTML5 permits us make the 
link presentational. And so, what is the difference between making it 
presentational and making it a an image?

For example, imagine that the above <img> did not have an empty @alt 
but one which said "Studio photo of a slightly younger Mike Walace." 

In fact John Foliot discusses a similar case here: 
<http://john.foliot.ca/aria-hidden>. Though John only discusses it from 
a duplicate links perspective. Like I described above, the image might 
be good in itself, but unclear as a "link image". In which case *one 
way* to remove the confusion can be through doing <a role=img>.
-- 
Leif Halvard Silli

Received on Monday, 9 April 2012 13:41:19 UTC