Re: Applicability of native semantics when ARIA roles used

On 24/08/2017 18:30, Jonathan Avila wrote:
> What needs to be clarified in the name calculation spec is when and what is used to determine the accessible name from the native semantics when the role attribute is used.
> I would assume <img role="heading" src="this.png" alt="This"> should not have an accessible name of "this" because alt is not a validate mechanism for an accessible name on a heading.  But what I hear you saying is that alt will be pulled in as a valid accessible name for the image but then the image role will be changed to a heading but the accessible name will be maintained.  This is not clear in the spec at what point this transubstantiation occurs.

That's not quite it. In your example, the browser recognises the element 
as an image in spite of the explicit role, not because of it.

<img alt="this" ...>

Is treated in exactly the same way as:

<img role="img" alt="this" ...>

Explicit roles only exist in the accessibility tree. So an img element 
with a role of heading is still an image, and the browser calculates an 
accessible name accordingly.

It's because of apparent conflicts like this, that changing an element's 
implicit role is generally cautioned against. It's too easy to end up 
with an element that is one thing and has all its associated 
characteristics, but which is exposed with a completely different role 
in the accessibility tree.

That said, the Acc Name and Description spec is one of the most 
difficult to read IMO. It could do with clarifying this, and a bunch of 
other things besides I think!


@LeonieWatson Carpe diem

Received on Thursday, 24 August 2017 18:27:12 UTC