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Re: clarification sought on publishing alt text document as a WG note

From: Steve Faulkner <faulkner.steve@gmail.com>
Date: Wed, 15 Oct 2014 06:39:05 +0100
Message-ID: <CA+ri+V=G7d_4syr7Fer9xE1UN+uRyJe=RXwYVvF1f7CTwNhbug@mail.gmail.com>
To: Liam R E Quin <liam@w3.org>
Cc: Sam Ruby <rubys@intertwingly.net>, HTML Accessibility Task Force <public-html-a11y@w3.org>


HTML 5.1 <http://www.w3.org/html/wg/drafts/html/master/>

On 14 October 2014 23:27, Liam R E Quin <liam@w3.org> wrote:

> On Tue, 14 Oct 2014 22:52:45 +0100
> Steve Faulkner <faulkner.steve@gmail.com> wrote:
> > On 14 October 2014 22:26, Liam R E Quin <liam@w3.org> wrote:
> >
> > > Adding a note about the fact that Web browsers may truncate an alt
> > > atribute value when rendered, to fit it into space reserved into an
> image
> >
> >
> > I would suggest more testing
> +1
> > adding a note as
> > you suggest is not helpful as it oversimplifies the observed behaviours
> of
> > browsers for display of images when images are disabled or unavailable.
> Probably we should try & get consensus on the issues around this on the
> TF; however, a note that suggests the alt text may be unavailable, or only
> partly available, would seem more useful to me to content authors and to
> developers than silence.

I suggest adding a note without providing any actionable advice for a
developer is worse than silence.

> >[...]
> > I started looking into browser behaviour again more recently I have
> > observed that Chrome does not display alt text for *any* images when
> images
> > are disabled through browser settings.
> Yes; in other words alt text should not be relied on for long or detailed
> descriptions for the case where a sighted user has turned off images, or
> where some or all of the images don't load.

I don't think it is helpful to view everything through the prism of "long
or detailed descriptions" since the cases where an image requires one is
far far outweighed and outnumbered by the cases where an image needs a
short alt text. Chromes current behaviour means ANY image alt text is not
displayed. I have filed a bug on chrome [
https://code.google.com/p/chromium/issues/detail?id=423629] your statement
would be more informed if it read.

"in other words alt text should not be relied on for the case where a
sighted user has turned off images, or where some or all of the images
don't load."

> At any rate I made a bug for it some time ago, so that it could be
> reviewed. A "best practice" document has to try to avoid telling people to
> do things that don't work :-)

Suggest appointing an editor to review. alt text works for the primary use
case (provision of an accessible name for an image) regardless of whether
its displayed on screen or not. I suggest we should not be telling
developers to modify what they provide as an alt text based on alt text
display bugs in some browsers as it just adds another dimension of
complexity to what many already see as an onerous task (providing alt text)
and could well lead to some developers deciding not to bother to provide
alt text, an outcome I think we can agree is sub optimal.

> I can add to your test page, by the way, that current firefox wraps the
> value of the alt attribute in the space available, if the img element has
> height and width attributes; I believe it truncates when it runs out of
> room, but haven't tested that recently. I tested on Linux, FireFox 33.  I
> didn't try with css width and height properties and overflow: truncate (for
> example); that would probably do the same thing.
> Thanks for the links,
> Liam
> --
> Liam Quin - XML Activity Lead, W3C, http://www.w3.org/People/Quin/
> Pictures from old books: http://fromoldbooks.org/
Received on Wednesday, 15 October 2014 05:40:13 UTC

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