RE: Adaptive Image Element Proposal

> From: Mathew Marquis [mailto:mat@matmarquis.com]
> > On Aug 30, 2012, at 1:10 PM, Adrian Roselli wrote:
> >> From: Leif Halvard Silli [mailto:xn--mlform-iua@målform.no]
> >>> Adrian Roselli, Thu, 30 Aug 2012 15:30:41 +0000:
> >>>> From: Leif Halvard Silli [mailto:xn--mlform-iua@målform.no]
> >>>>> Adrian Roselli, Thu, 30 Aug 2012 13:18:24 +0000:
> >>>>>>> From: Leif Halvard Silli, Thursday, August 30, 2012 8:53 AM
[...]
> >> Well, since I suggest that it should be possible to drop the @alt and
> >> just let aria-labelledby point to the picture element, I already
> >> operate with a more complicated rule. So I maintain that this as a
> >> proposal to the picture element editors.
> >
> > It is a bit more complicated. It also feels more complicated than the
> replicated @alt, which doesn't mean you can't use ARIA.
> 
> I agree. Now, likewise, I see no reason why `aria-labelledby` couldn't be used
> here, but I'm not convinced we should make it a requirement. If `aria-
> labelledby` pointed at `picture` doesn't work outside of browsers that
> natively support `picture`, we've painted ourselves into a corner-the
> fallback `img` won't be able to reference it. Even if this isn't the case, we'd
> still be limiting the accessible text to browsing contexts that support `aria-
> labelledby` - and speaking as an author (and one comfortable and familiar
> with ARIA attributes), I'm not convinced that this is the more intuitive option.
> It might be best to open that question up to the RICG before we make any
> decisions on that basis. I certainly don't claim to speak for everyone!
> 
> Likewise, I'm unsure as to whether an `aria-labelledby` attribute on `picture`
> pointing at the fallback `img` will be able to access that value in browsers that
> do support `picture` and don't receive the fallback. I'll defer to someone
> more knowledgeable than I here, but that case does seem a lot more likely.
> 
> If that's a viable approach, would it make sense to specify that the UA should
> ( given the absence of an `alt` attribute on the `picture` element ) defer to
> the fallback content for the `alt` by default? Else, if everyone feels that

I feel that is easier for authors and toolmakers -- no need to worry about duplicating @alt to <picture>. But then a missing <img> is akin to a missing @alt, so the <picture> should still support @alt (for a missing <img>/@alt fallback scenario) or it should just require <img> and the @alt requirement comes along with it.

> decision is better left to authors, would it be possible to specify that either
> approach is valid: either specifying an identical `alt` attribute on both `picture`
> and the fallback `img`, or though the use of `aria-labelledby`?

While I suspect that's possible, that seems like it will be a little convoluted when spelled out for authors. I think <img>/@alt should be required and @aria-labelledby should be promoted as a companion, not a replacement.

Received on Thursday, 30 August 2012 18:57:32 UTC