Re: Flickr and alt

Justin James 2008-08-19 22.38:

>> Leif Halvard Silli Sent: Tuesday, August 19, 2008 2:49


>> It seems to me that the understanding of conformance versus 
>> validation could be improved by requiring the role=""
>> attribute, and have spesific @alt requirements for each role.
> 
> The techno-geek in me loves this idea. The pragmatist in me
> says that it makes things too complicated for the typical HTML
> author. :(
> 
> Unless, of course, we assign a default @role for @role="" and a
> missing @role, and the default @role has @alt rules of "@alt
> must be present (even with a value of empty string), see WCAG
> for information on how to use it." That would take the entire
> thrust of Karl's proposal and merge it with this excellent idea
> presented here. The large majority of HTML authors who are
> savvy enough to use @role will also be able to follow along
> with the idea that @role can affect @alt requirements.

A default @role value? Perhaps. Against 1: The presence of @role 
is very simple to validate. So why allow omitting it? To validate 
HTML 4 docs as if being HTML 5? Against 2: What validation 
response should lack of @role then lead to?

Some tryouts for the last question: If the default value was

(1) somethign requiring alt text => endless requests for alt text 
(though the author could add @role to get rid of many of them.)
(2) role="decorative" => endless requests for @alt text removal.
(3) role="undefined" => error response = not what you wanted.
(4) role="private-undefined" (the name of the default role should 
seem unfitting for "public" pages) => validator announces

 (a) the lack of @role; (b) the name of the default role (c) that 
such a value is incorrect for pages which are corporate, 
governmental or public, and for all other pages in need of a 
measure of universal access and accessibility (d) that the @alt 
can not be evaluated before @role is added (though the presence of 
@alt, and - possibly - repeated alt values could be evaluated, 
depending on how the defult value was defined, and always with an 
advice to add @role before editing the @alt attribute).

Over all, @role would open many new possibilities for better 
validation services:

Repeated alt could trigger a response. (It would be ok for IMG-s 
with e.g. role=logo, but unexpected with some other roles.) Some 
loopholes could become narrower. (Use of white-space in order to 
achieve conformance should e.g. throw an error if the role is 
role="logo".) @Role would allow the validator to apply 
"heuristics". (E.g., for advice, the validator could "calculate" 
whether the presence of role="logo" one one IMG, lowers or 
increeases the chance that role=private-undefined on another seems 
correct, or not.)
-- 
leif halvard silli

Received on Wednesday, 20 August 2008 02:13:17 UTC