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Re: ACTION-282 - Create a list of alternatives available for content for inclusion in the techniques

From: Greg Lowney <gcl-0039@access-research.org>
Date: Thu, 11 Feb 2010 14:42:56 -0800
Message-ID: <4B7487F0.4050506@access-research.org>
To: WAI-UA list <w3c-wai-ua@w3.org>
In response to the question asked on today's call, when you select any content in Firefox its context menu will include a "View Selection Source" command. Similar functionality is available using the "View Selection Source" add-in for Safari. 

There is a related add-in for Firefox called "Veiw Rendered Source" that shows the source after any modifications by scripts, etc. There is apparently a commercial equivalent for Internet Explorer called "Instant Source".

The filename associated with an IMG tag can be seen in most browsers using the image's Properties. There was also an "Image Name Copier" that added a context menu item to copy the name to the clipboard.

A nice trick is the ability to install a user style sheet that would add display your choice of attributes before or after your choice of items. Here's some sample HTML+CSS that demonstrates:

<html>
<head>
<title>Testing generated content</title>
<style>
div.test:after { content: attr(title); color: red; font-weight: bold;}
p:after { content: "\A[" attr(title) "]"; color: purple; font-weight: bold;}
img:before { content: "[" attr(title) "]"; color: green; font-weight: bold;}
img:after { content: "\A[alt=" attr(alt) "]\A[title=" attr(title) "]"; color: purple; font-weight: bold; background-color: yellow;}
</style>
</head>
<body>
<div class="test" title="This is a test div">
<p title="This is a test paragraph">Hello there!</p>
<img src="bollards.jpg" title="Bollards!" alt="Bollards on the waterfront" >
</div>
</body>
</html>

One should be able to install a user style sheet that would apply these to all pages you view (e.g. follow all images with their alt or title) without having to write any scripts.

Unfortunately, support for this is spotty: 
* Opera 10.1 fails to support \A for line breaks.
* Firefox 3.5 fails to support generated content on IMG tags, \A for line breaks, or  background-color on generated content.
* Safari 4 fails to support generated content on IMG tags, \A for line breaks, or background-color on generated content.

(I haven't tried other browsers.)

(Note that both Firefox and Safari support setting the foreground color for generated content, but not the background color, which can lead to incorrect color combinations that may be inaccessible to the user.)

Also unfortunately, while you can show a single value only if it exists (e.g. content="attr(title)"), and concatenate more than one with our without additional punctuation (e.g. content="[title:" attr(title) " alt:" attr(alt) "]") as far as I can tell you'd have to use a script to do this while showing nothing if neither exists.

-------- Original Message  --------
Subject: Re: ACTION-282 - Create a list of alternatives available for content  for inclusion in the techniques
From: Greg Lowney <gcl-0039@access-research.org>
To: WAI-UA list <w3c-wai-ua@w3.org>
Date: 2/9/2010 6:10 PM

That's a very useful list!

In addition, there are other pieces of information which can prove 
useful as alternative content when nothing else is available or in 
special circumstances, and thus it can be useful for UA to make them 
available to the user. These include:
a) raw HTML associated with an element or range,
b) filename associated with an IMG,
c) title attribute for any element

-------- Original Message  --------
Subject: ACTION-282 - Create a list of alternatives available for 
content for inclusion in the techniques
From: Jim Allan <jimallan@tsbvi.edu>
To: 'UAWG list' <w3c-wai-ua@w3.org>
Date: 2/9/2010 12:08 PM

These are the elements and attributes the seem to present 'alternative
content' relevant to Guideline 3. Additions welcome.

Alternative content
@alt for IMG
@alt for AREA
@alt for INPUT type=image
@alt for EMBED
@longdesc for IMG
@longdesc for FRAME
@longdesc for IFRAME
@summary for TABLE
@abbr for TH
@title for A
@title for ABBR
@title for ACRONYM
@title for many other things (SPAN
http://dev.w3.org/html5/spec/Overview.html#footnotes) @cite for Q
'fallback content' for OBJECT
'fallback content' for EMBED
'fallback content' for CANVAS
Caption tracks for VIDEO
Audio Description tracks for VIDEO
@srcdoc for IFRAME
(http://dev.w3.org/html5/spec/Overview.html#the-iframe-element) DETAILS 
& SUMMARY elements
http://dev.w3.org/html5/spec/Overview.html#the-details-element (? This is a
user widget for the user to get additional information provided by the
author but only available on request.)
@title (hint) for COMMAND
http://dev.w3.org/html5/spec/Overview.html#using-the-command-element-to-defi 

ne-a-command

Jim Allan, Accessibility Coordinator & Webmaster
Texas School for the Blind and Visually Impaired
1100 W. 45th St., Austin, Texas 78756
voice 512.206.9315    fax: 512.206.9264  http://www.tsbvi.edu/
"We shape our tools and thereafter our tools shape us." McLuhan, 1964
Received on Thursday, 11 February 2010 22:45:21 GMT

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