W3C home > Mailing lists > Public > public-html-bugzilla@w3.org > March 2010

[Bug 9214] Allow role="presentation" on img

From: <bugzilla@wiggum.w3.org>
Date: Wed, 24 Mar 2010 04:10:48 +0000
To: public-html-bugzilla@w3.org
Message-Id: <E1NuHvc-0006jk-R2@wiggum.w3.org>
http://www.w3.org/Bugs/Public/show_bug.cgi?id=9214





--- Comment #13 from Ian 'Hixie' Hickson <ian@hixie.ch>  2010-03-24 04:10:47 ---
<img src="foo" alt="bar"> means "I have an image that means bar".
<img src="foo" alt=""> means "I have a presentational image that isn't
important".
<img src="foo"> means "I have an important image but I don't know what it is".

>From an architectural point of view, this is the semantic layer of HTML. It
defines the meaning of the language.

On top of this we can put ARIA, which are a way to adjust the semantics for the
AT layer, just like CSS is a way to adjust the semantics for the presentational
layer.

So:

<img src="foo" alt="bar" role="baz">
  ...means "I have an image that means bar and whose accessibility role is
baz".
<img src="foo" alt="" role="baz">
  ...means "I have a presentational image that isn't important but whose
accessibility role is baz".
<img src="foo" role="baz">
  ...means "I have an important image but I don't know what it is except that
it is a baz role".

Making alt="" be implied by role="presentation" would IMHO therefore be a
layering violation, making the accessibility layer imply semantic meaning at
the HTML layer. It would IMHO be analogous to having the CSS or JS layers
affect the conformance of markup. I believe doing this would be a design
mistake.

Sometimes, language design pales in importance compared to larger goals, such
as making a particular action possible, or addressing compatibility issues.
However, in this particular instance, it does not appear that adding this hack
would actually improve authoring matters at all: it is far easier for authors
to say alt="" than role-"presentational". Since this therefore provides no
benefit to authors and no benefit to implementors, it seems that language
design is relevant, and we should avoid such layering violations.

It would be helpful if Laura (the bug reporter) could confirm that we are
talking about what she meant when she filed the bug, though. The original
comments don't really match what we're talking about as far as I can tell.


-- 
Configure bugmail: http://www.w3.org/Bugs/Public/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the QA contact for the bug.
Received on Wednesday, 24 March 2010 04:10:50 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Wednesday, 24 March 2010 04:11:04 GMT