[html4all] some reflections on @alt usage

[Leif Halvard Silli]

Jason White 2008-04-29 12.36:
> On Tue, Apr 29, 2008 at 06:00:31AM -0400, Vlad Alexander wrote:
> > And that will not change until major Web browsers will begin to report
> > invalid markup to the users in some way. There is no incentive for tool
> > vendors to generate standards-compliant markup if it gets treated by Web
> > browsers the same as tag soup. In fact, HTML 5 will make the problem even
> > worse. HTML 5 will help Web browsers parse tag soup better which will then
> > provide less incentive for authors and tool vendors to author Web pages to
> > specification and thus creating more tag soup on the Web.
>   

Vlad, why can't such tools have error checkers anyhow? Why can't 
browsers have them? iCab has always had one.  (But, ps, the idea had 
about an unready stamp comes to mind. It does not seem appropriate to 
receive the full load of errors messages at all steps of the author 
process.)

> This is why I suggested in an earlier contribution that the @alt discussion is
> ultimately a question of what markup validators should treat as acceptable.
>   
> If you accept the premise of HTML 5 that user agents should parse and handle
> broken markup in predictable, specified ways, then the question inevitably
> arises as to how missing @alt should be treated.
> I doubt that it makes much practical difference whether @alt is
> mandatory or optional in the grammar, given that if it is missing, error
> handling will have to be specified (or left for implementations to define)

Jason, now that you say it, this sounds so obvious.  And it makes me 
think that the ideas driving HTML 5 has not been implemented when it 
comes to @alt. At least, I see no error handeling being specified.

Yes, of course, it would be entirely in the spirit of HTML 5 to say that 
a missing alt should be corrected in the DOM. To put it like that would 
be to say that a missing ALT is, in fact, an error. Correcting it in the 
DOM should also help screen reader users, since they need to read the 
web through a graphical User Agent.

To leave the issue to the implementations to define, does not seem to be 
in the spirit of HTML 5, as it would be unpredictable.

So, what should the DOM do with a missing alt? Should it always be 
corrected in the same way, for instasnce by enumerating the images in a 
certain way? Or can some contexts be identfied, and some contextual 
error handeling be specified?
-- 
leif halvard silli