[whatwg] add html-attribute for "responsive images"

[Bjartur Thorlacius]

On Wed, 08 Feb 2012 17:16:36 -0000, Anselm Hannemann - Novolo  
Designagentur <anselm at novolo.de> wrote:
> Okay, I talked with some disabled web developers and Accessibility  
> experts today and talked about the proposal of markup in alt-text.
> This seems not to be a good idea as screenreader would read the tags  
> which would confuse many users then.
> So we would get into trouble with that approach according to current  
> screenreader features, etc.
>
This applies only to attributes. Elements can and do have element  
children, while attributes can only contain plain text. We should not  
redefine the alt attribute. A new element has been proposed in the list  
whose contents can be defined to be an alternative representation of the  
linked resource. Preferably we could just reuse elements and semantics  
where appropriate.

<Object data="lolcats.gif title="An animated image macro of mine"  
type="image/gif">
  <p><b>Nazi Cats</b></p>
  <p>Humans have been obsoleted.</p>
</Object>

<Object data="lolcat.gif" title="An animated image macro of mine"  
type="image/gif">
  <Img src="lolcat.jpeg" title="An image macro of mine" alt="Nazi Cats.  
Humans are now obsolete.">
</Object>

As has been pointed out in the thread already, using <object> fallbacks of  
different media types may result in strange behavior, and is hard to  
implement correctly.