WebAIM - Web Accessibility In Mind

E-mail List Archives

Re: Graphics and Captions


From: Patrick H. Lauke
Date: Jan 20, 2006 7:30PM

Kynn Bartlett wrote:

>> * As a style sheet selector (when an author wishes to assign style
>> information to a set of elements).
>> * For general purpose processing by user agents."
>> Source: <http://www.w3.org/TR/html4/struct/global.html#adef-class>;
> There are no other "general purpose processing" functions defined.

So they can be user agent, or even site specific.

>> I'm not saying that we should assume that there is any semantic meaning
>> behind class names - currently there isn't a lot save for the work being
>> done with microformats. There is nothing saying that we can't establish
>> some and use the class attribute for things beyond presentational hooks.
> Except they're not established, and besides, doing so will simply mix
> presentational markup with semantic markup, and we'll be back to the
> original problem we had in the first place.

No, it will not mix presentational markup with semantic markup because
class attributes are not presentational to begin with. Yes, as you noted
the primary use of class names is to later use them as selectors to
define presentation, but class names themselves are not presentational
(unless of course you use misguided class names like "bold" or "red")

>> And doing so might actually be a way to enhance the accessibility of the
>> web sites and applications we build.
> How? Any potential benefits of trying to convey content semantics via
> class is dubious and doomed to failure, when the real solution is to
> expand the actual semantic markup.

I would say that I can't see microformats directly benefitting
accessibility (as in a user agent making direct use of them)...but, when
combined with tools such as transformers which go through a page looking
specifically for microformat information and reformatting it
(server-side...or maybe even client side) to adapt to user preferences
they can be a good thing from both a usability and accessibility point
of view.

> Sure, you could also use the style attribute for something other than
> just presentation, but that's a bad idea for the same reason. Classes
> are defined in the spec to be "presentational, PLUS MAYBE something
> else."

And here we are now, working on examples for this "PLUS" that are viable
*today*, with current technology...not once we have our jetpacks and
enjoy XHTML2.0+

> We so totally don't want to go down that path toward "something else."
> Wrong route entirely.

I don't see it as a route into the far future...but it's a stopgap
solution until extensible markup is consistently supported even in IE
and there are no backwards compatibility worries anymore (IMHO, anyway).

> Because recent history teaches us that trying to misuse presentational
> and/or semantic markup as each other only leads to headaches.

But again, class names (and id) are not inherently presentational. Their
common application is to use them to apply presentation in a subsequent
step. They can quite happily carry meaning, though that meaning may not
be universally understood by all user agents (in which case no harm is
done, as it's still within spec) but only by specific server- or
client-side processing tools.

Patrick H. Lauke