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Re: providing a long description using the summary and details elements.

From: Laura Carlson <laura.lee.carlson@gmail.com>
Date: Wed, 25 Aug 2010 08:08:20 -0500
Message-ID: <AANLkTin_QXemLNAAwsW1ayUWg0T4LBRVU1Cd4x7RinS0@mail.gmail.com>
To: Steven Faulkner <faulkner.steve@gmail.com>
Cc: HTMLWG WG <public-html@w3.org>, HTML Accessibility Task Force <public-html-a11y@w3.org>
Hi Steve,

>>Could it work cleanly without JavaScript and no disclosure triangle?
>
> When the details/summary is implemented in browsers it is expected that the
> widget behaviour will not require javascript.

That's good. I hope it works well.

> As for the disclosure traingle i guess that develpers will be able to
> manipulate the visual appearance via CSS.

@longdesc doesn't have that problem for visual designers to hack
around. They would be trying to make a visual indicator disappear
while keeping the long description text audible to the user. Kind of
the same type of hack as trying to use @hidden.

> But i would suggest that the
> disclosure widget being visible is a good thing as it is unobtrusive but
> lets everyone know that there is additional content.

In some cases this may true. In others it would not be true. It
depends on audience and author. To some it would be totally
unacceptable because it would compromise aesthetics. Artists,
designers and marketers will not want their visual designs
changed/ruined; whether that's with visible link text or a disclosure
widget.

Like the alt attribute (btw, no one has suggested a disclosure widget
for alt), long descriptions are primarily written for the blind and
visually impaired who use screen readers. Longdesc content if written
correctly is  redundant for people who can see because it's aim is to
provide what the visual provides.

However, user agents providing an option to reveal the content of
longdesc affords a practical method for the curious and for developers
who want a tool to check the longdesc text and keep it up to date.
User agents should be encouraged to make longdesc visible on demand
(not by default) by providing a context menu, preference, or switch of
some sort. Such a toggle could be used for @alt, @summary visibility
too.

>> HTML4's longdesc is such a simple solution to the problem. This seems
> complicated to me.
>
> when implemented i don't think it will be complicated in its most basic form
> its simple as:
> <details>
> <summary><img alt="text"></summary>
> long description
> </details>

That's very good. "When implemented" is key here.

Details/summary has potential to give authors an additional tool. I
thank you very much for thinking of it, Steve.

But even with this details/summary option, no functional replacement
for longdesc exists in HTML5.

Best Regards,
Laura

> On 24 August 2010 18:01, Laura Carlson <laura.lee.carlson@gmail.com> wrote:
>
>> Hi Steve,
>>
>> > an idea:
>> >
>> > using the summary /details elements to provide a long description
>>
>> Wow Steve. This is cool. Thanks for thinking outside of the box.
>>
>> Could it work cleanly without JavaScript and no disclosure triangle?
>> HTML4's longdesc is such a simple solution to the problem. This seems
>> complicated to me.
>>
>> Sidebar: Something to keep in mind for the examples is that charts and
>> graphs are not usually interchangeable with data tables so they don't
>> usually make good long descriptions.
>>
>> Designers create data visualizations for the sighted because it makes
>> the data easier to understand than raw numbers in a table. Ideally, a
>> chart should convey ideas about the data that would not be readily
>> apparent if available only in a table (but the table could be included
>> too). A longdesc for a data chart should try to communicate the
>> relationships, treads, etc that the image is intended to convey. Some
>> analysis is typically required to describe the data. It's tempting to
>> use a table as the sole content for a longdesc but that usually isn't
>> enough.
>>
>> Joe Clark talked about this a few years ago in a WCAG comment. [1]
>> WCAG revised their example after his comment to:
>>
>> "A bar chart compares how many widgets were sold in June, July, and
>> August. The short label says, "Figure one - Sales in June, July and
>> August." The longer description identifies the type of chart, provides
>> a high-level summary of the data, trends and implications comparable
>> to those available from the chart. Where possible and practical, the
>> actual data is provided in a table."
>>
>> Best Regards,
>> Laura
>>
>> [1]
>> http://www.w3.org/WAI/GL/WCAG20/issue-tracking/viewdata_individual.php?id=789
>>
>> On 8/24/10, Steven Faulkner <faulkner.steve@gmail.com> wrote:
>> > Hi all,
>> > an idea:
>> >
>> > using the summary /details elements to provide a long description for an
>> > image:
>> >
>> >
>> >    - image goes in the <summary>
>> >    - long description in <details>
>> >    - use of longdesc attribute on image provides indication to
>> > browser/AT
>> >    that details/summary is being used for the specific purpose of
>> providing
>> > a
>> >    long description.
>> >    - longdesc attribute with URL value (longdesc="URL") provided for
>> >    backwards compatibility (suggest deprecated in HTML5)
>> >    - longdesc attribute without an URL "longdesc" be specced as an
>> indicator
>> >    that a long description is present when image is sole content of the
>> > summary
>> >    element.
>> >
>> >  example code:
>> >
>> > <details>
>> >   <summary role="button"><img src="images/table.gif" alt="Average
>> rainfall
>> > in millimetres by country and season." width="407" height="341"
>> > longdesc="details.html#table"></summary>
>> >
>> > <table border="1" id="table" tabindex="0"><caption>Rainfall in
>> millimetres
>> > by Country and Season.</caption><tr> <td></td><th scope="col">UK</th><th
>> > scope="col">Japan</th><th scope="col">Australia</th></tr><tr> <th
>> > scope="row">Spring</th><td>5.5</td><td>2.4</td><td>2</td></tr><tr> <th
>> > scope="row">Summer</th><td>4.5</td><td>3.4</td><td>2</td></tr><tr> <th
>> > scope="row">Autumn</th><td>3.5</td><td>1.8</td><td>1.5</td></tr><tr> <th
>> > scope="row">Winter</th><td>1.5</td><td>1.2</td><td>1</td></tr></table>
>> >
>> > </details>
>> >
>> > sort of working example
>> > http://www.paciellogroup.com/blog/misc/details.html (haven't
>> > had time to work out glitches, but gives an idea of how it could work,
>> > doesn't work in IE yet. note: scripting would not be required once
>> > details/summary implemented by browsers).
>> > resolves issues of:
>> >
>> >    - providing *standardized* method for a programnmatically associated
>> long
>> >    description
>> >    - provides it inline next to the image
>> >    - only displayed on user request
>> >    - does not clutter design (note example does not a disclosure
>> > triangle
>> as
>> >    is suggested for details/summary in spec, but this would not clutter
>> > desigh
>> >    , i don't think)
>> >    - deprecates current longdesc use, but provides for backwards compat
>> and
>> >    continued use of longdesc attribute
>> >    - details could conatin a.n <iframe> to display long descriptions
>> >    external to the page.
>> >    - long desc available to anybody who wants it.
>> >
>> >
>> >
>> > --
>> > with regards
>> >
>> > Steve Faulkner
>> > Technical Director - TPG Europe
>> > Director - Web Accessibility Tools Consortium
>> >
>> > www.paciellogroup.com | www.wat-c.org
>> > Web Accessibility Toolbar -
>> > http://www.paciellogroup.com/resources/wat-ie-about.html
>>
>> --
>> Laura L. Carlson
>>
>
>
>
> --
> with regards
>
> Steve Faulkner
> Technical Director - TPG Europe
> Director - Web Accessibility Tools Consortium
>
> www.paciellogroup.com | www.wat-c.org
> Web Accessibility Toolbar -
> http://www.paciellogroup.com/resources/wat-ie-about.html
>


-- 
Laura L. Carlson
Received on Wednesday, 25 August 2010 13:08:52 GMT

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