Re: what must be done to expose longdesc? [was Re: fear of "invisible metadata"]

On Fri, Jun 29, 2007 at 10:12:54AM +0100, Joshue O Connor wrote:
 
> Another possibility is to multipurpose @alt so it also doubles up as a
> LONGDESC. So you have one attribute that you can use for both purposes
> as required?

This is an interesting idea. I suppose TITLE could still be used to provide a
short label for the image, independently of the longer description referred to
by ALT, in cases where both a short label and a full description are
warranted.

The main problem with this proposal is that in processing the value of ALT,
the user agent would have to determine whether it is a URI, then retrieve the
associated resource if so, otherwise render the text of the attribute value.
This would also leave the value of ALT syntactically unconstrained, whereas
with a LONGDESC attribute, the syntax can be checked to ensure that it is a
URI.

Backward-compatibility with ua's that always render ALT would also serve as an
argument against this proposal, though, in my view, not necessarily a fatal
one.