[whatwg] ALT and equivalent representation

[Simon Pieters]

On Mon, 21 Apr 2008 08:48:06 +0200, Shannon <shannon at arc.net.au> wrote:

> Benjamin Hawkes-Lewis wrote:
>>
>> I think you've misunderstand Simon's suggestion, which was:
>>
>> <p>Rating: <img src=1 alt=3/5><img src=1 alt><img src=1 alt><img
>>    src=0 alt><img src=0 alt></p>
>>
>> Note /all/ the img elements have alt attributes, the point is the  
>> alternative text for the group is expressed by the first alt attribute.  
>> It's thus actually the same as the fallback you propose:
>>
> Not the same thing at all. There is no direct association between the  
> elements so there is no way a validator or browser would know the  
> difference between a missing/empty alt and an optional one - thus making  
> ALL use of alt optional as far as formal validation is concerned.

Automated conformance checking of alt is not possible anyway. It needs  
human investigation with knowledge of the context in which the image in  
question finds itself. Therefore, extra markup for aiding conformance  
checking is not helping anyone -- on the contrary it adds more cruft for  
the person checking for conformance.

As for browsers, the goal there is to replace all images with their  
replacement text, and the result of both the above and your proposal would  
be:

    Rating: 3/5

Hence, your extra markup isn't helping browsers either. Moreover, it  
doesn't degrade nicely with existing UAs unless the author goes an extra  
mile and add alt to all the images (in which case the extra markup becomes  
pointless again).

-- 
Simon Pieters
Opera Software