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Re: css abuse

From: Ian Jacobs <ij@w3.org>
Date: Mon, 04 Oct 1999 16:08:59 -0400
Message-ID: <37F9095B.83E45145@w3.org>
To: "Leonard R. Kasday" <kasday@acm.org>
CC: Al Gilman <asgilman@iamdigex.net>, w3c-wai-er-ig@w3.org, jongund@staff.uiuc.edu
"Leonard R. Kasday" wrote:
> 
> Continuing from Al's intro...
> 
> This came up to cover the following case.  A web page author want to define
> "new" parts of a page in a color like red.  Instead of using a font tag,
> the author defines a class "new" and uses a style sheet to present it in
> red.  So far so good.

It depends on what you mean. If you mean that for style alone, then
ok. But "new" suggests semantics and what's needed is some semantic
description:

a) In a spec like for HTML (for "new" in HTML use INS).
b) A new element + a schema. 

I don't think "class" names convey semantics effectively without
a formal mechanism for assigning meaning. How else is the machine
to guess what it means? What about values in languages other than
what the user knows?
 
> But for this to benefit the blind user:
> 
> 1. The user agent must announce the class names to the user

What about these instead:

  1a) Authors should provide alternative style sheets.
      (e.g., aural style sheets for speech output). User agents
      must allow users to select from available style sheets.

> 2. The web content guidelines must specify that class names be mnemonic and
> useful.

The "class" attribute is for machines, isn't it? 
I don't see how one can rely on human 
interpretation of class values. What if they're in another language? 

> 3. The authoring tools should make is simple to change the class name, in
> case the initial choice is not good. 

According to whom?

> This would involve changing it
> throughout the style sheet and all pages using the style sheet.
> 
> In fact, it would be even better if the text announced to the user could be
> independent of the name of the class, just like ALT text is independent of
> the filename chosen for a file.
> 
> Al points out how this can be considered implicit in what we have already
> (except for the very last point).  I'd suggest though that it be made
> explicit in the user agent, web content, and authoring tools.
> 
> Len
> 
> At 12:27 PM 10/4/99 -0400, Al Gilman wrote:
> >Briefly, the area under discussion has to do with class tokens that are
> >applied to elements in the HTML markup.
> >
> >The DOM core requirements will expose these values because they are
> >attributes.  So the API requirement to share the document contents in
> >accordance with the W3C DOM means AT software has access to these through
> >this API.
> >
> >The part I am vague about is how the guideline that the browser through its
> >own UI should give the user access to all content is being interpreted as
> >regards CLASS tokens.  IMHO they should be covered; the CLASS tokens are
> >metadata and I am arguing that authors should set them in a mnemonic
> >fashion as well as eventually tie them to schemata for more precise
> >machine-processable definitions.
> >
> >This is just an intro; please glance over the thread on w3c-wai-er-ig in
> >the archives. Use "css abuse" in the subject to find the thread.
> >
> >Al
> >
> >At 10:22 AM 10/4/99 -0400, Ian Jacobs wrote:
> >>Al Gilman wrote:
> >>>
> >>> At 09:17 PM 10/3/99 -0400, Leonard R. Kasday wrote:
> >>> >
> >>> >>And yes, a UAGL-conforming user agent not only has access to these
> >>> >>attribute values, but makes them available to the user and to add-on
> >>> >>assistive technologies.
> >>> >
> >>> >I think we'll have to coordinate with the Guideline and Authoring
> >groups to
> >>> >make that point explicit.
> >>> >
> >>> >I can't find any explicit mention of CLASS name being readable in the
> user
> >>> >agent guidelines or the web content guidelines.
> >>>
> >>> Talk to Jon or Ian about where the drafts and issues are.  They are
> >>> wrestling with how to make the guideline transcend HTML and yet make the
> >>> checkpoints clear.
> >>
> >>Could you please describe the requirement?
> >>
> >> - Ian
> >>
> >
> >
> -------
> Leonard R. Kasday, Ph.D.
> Institute on Disabilities/UAP, and
> Department of Electrical Engineering
> Temple University
> 
> Ritter Hall Annex, Room 423, Philadelphia, PA 19122
> kasday@acm.org
> (215) 204-2247 (voice)
> (800) 750-7428 (TTY)

-- 
Ian Jacobs (jacobs@w3.org)   http://www.w3.org/People/Jacobs
Tel/Fax:                     +1 212 684-1814
Cell:                        +1 917 450-8783
Received on Monday, 4 October 1999 16:09:50 UTC

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