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_________________________________________________________________
W3C
Non-W3C Techniques for Web Content Accessibility Guidelines 1.0
W3C Working Draft 20 July 2000
This version:
http://www.w3.org/WAI/GL/WD-WCAG10-NONW3C-TECHS-20000720
(plain text, postscript, pdf, gzip tar file of HTML, zip
archive of HTML)
Latest version:
http://www.w3.org/WAI/GL/WCAG10-NONW3C-TECHS
Previous version:
http://www.w3.org/WAI/GL/WD-WCAG10-NONW3C-TECHS-20000705
Editors:
Wendy Chisholm, W3C,
Gregg Vanderheiden, Trace R & D Center, University of Wisconsin
-- Madison
Ian Jacobs, W3C
Copyright �1999 - 2000 W3C� (MIT, INRIA, Keio), All Rights Reserved.
W3C liability, trademark, document use and software licensing rules
apply.
_________________________________________________________________
Abstract
This document describes techniques for satisfying the checkpoints of
"Non-W3C Techniques for Web Content Accessibility Guidelines 1.0"
[WCAG10] when authoring with non-W3C technologies such as Flash.
"Techniques for Web Content Accessibility Guidelines 1.0"
[WCAG10-TECHS] contains additional techniques and references for other
formats and languages.
Status of this document
While Web Content Accessibility Guidelines 1.0 strives to be a stable
document (as a W3C Recommendation), the current document is expected
to evolve as technologies change and content developers discover more
effective techniques for designing accessible Web sites and pages.
This is a W3C Working Draft for review by W3C Members and other
interested parties. It is a draft document and may be updated,
replaced or obsoleted by other documents at any time. It is
inappropriate to use W3C Working Drafts as reference material or to
cite them as other than "work in progress". This is work in progress
and does not imply endorsement by, or the consensus of, either W3C or
participants in the Web Content Accessibility Guidelines (WCAG)
Working Group.
This document is part of a series of accessibility documents published
by the Web Accessibility Initiative. WAI Accessibility Guidelines are
produced as part of the WAI Technical Activity. The goal of the Web
Content Guidelines Working Group is discussed in the Working Group
charter.
A list of current W3C Recommendations and other technical documents
can be found at http://www.w3.org/TR.
Please send detailed comments on this document to w3c-wai-gl@w3.org.
Table of Contents
* Abstract
* Status of this document
* 1 Macromedia Flash
+ 1.1 Static images
+ 1.2 Providing alternative images
* Acknowledgments
* 2 References
* 3 Resources
+ 3.1 Accessibility resources
_________________________________________________________________
1 Macromedia Flash
1.1 Static images
Checkpoint in this section: 1.1.
The Macromedia Flash Generator may create simple (non-interactive)
animations or static images. When these images are included in an HTML
document with the IMG element, an "alt" attribute is required (per
Checkpoint 1.1).
To use Generator to dynamically output a .gif stream instead of a
Flash stream, add the "type=" attribute with an appropriate value.
Example:
<IMG
src="http://example.org/flashtemplate.swt?type=gif¶m1=val1¶m2=val2
<http://example.org/flashtemplate.swt?type=gif¶m1=val1¶m2=val2> "
height="111" border="0" width="222" naturalsizeflag="1"
align="BOTTOM" alt="Description of the Image">
Critical Elements: The "type=gif" parameter/value.
1.2 Providing alternative images
Checkpoint in this section:
* 6.5 Ensure that dynamic content is accessible or provide an
alternative presentation or page. [Priority 2]
It is possible to determine (via Javascript) if the user has installed
the Flash plug-in, and provide an alternative image if they have not.
Flash 4 has the capability to automatically generate this code,
however it is necessary to modify what is generated. This example
shows the resulting JavaScript code that should be used to determine
the presence of the Flash plug-in.
Example:
<!-- Image Map -->
<MAP NAME="AK"></MAP>
<SCRIPT LANGUAGE=JavaScript>
<!--
var UseFlash = 0;
if (navigator.mimeTypes && navigator.mimeTypes["application/x-shockwave-flash"]
) {
// Check for Flash version 3 or greater in Netscape
var plugin = navigator.mimeTypes["application/x-shockwave-flash"].enabledPlug
in;
if (plugin && parseInt(plugin.description.substring(plugin.description.indexO
f(".")-1))>=3
)
UseFlash = 1;
} else if (navigator.appName && navigator.appName.indexOf("Microsoft") != -1 &&
navigator.userAgent.indexOf("Windows") != -1 && navigator.userAgent.indexOf("W
indows 3.1") == -1) {
// Assume any Windows IE except for Windows 3.1 supports the
// OBJECT tag UseFlash = 1;
}
if ( UseFlash ) {
// Use Flash player
// Although these alt tags do not apparently seem to be supported with the p
lug-in,
// they are included on the chance they are supported in an upgrade
document.write('<object width="400" height="400" alt="Object Map
of Alaska" classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000" ');
document.write(' ');
document.write(' WIDTHU0 HEIGHT35
codebase="http://active.macromedia.com/flash2/cabs/swflash.cab#version=4,0,0
,0"
id="AK">');
//
// the next 'document.write' line will need to be modified to point to your
// file and to use your params
//
document.write('<param name="movie" value="http://example.org/flashtemplate.
swt?param1=val1�m2=
val2 <http://example.org/flashtemplate.swt?param1=val1�m2=val2> "><PARAM
NAME=quality VALUE=high> <param name="bgcolor" value="#FFFFFF"> ');
//
// the next 'document.write' line will need to be modified to point to your
// file and to use your params
//
document.write('<EMBED ALT="Embed Map of Alaska"
src="http://example.org/flashtemplate.swt?param1=val1�m2=val2
<http://example.org/flashtemplate.swt?param1=val1�m2=val2> " quality=high
bgcolor=#FFFFFF ');
document.write(' swLiveConnect�LSE WIDTHU0 HEIGHT35');
document.write(' TYPE="application/x-shockwave-flash"
PLUGINSPAGE="http://www.macromedia.com/shockwave/download/index.cgi?P1_Prod_
Version=ShockwaveFlash">');
document.write('</EMBED>');
document.write('</OBJECT>');
} else if (!(navigator.appName && navigator.appName.indexOf("Netscape")>=0
&& navigator.appVersion.indexOf("2.")>=0)) {
// Netscape 2 will display the IMG tag below so don't write an extra one
// You will need to modify the SRC param
document.write('<img src="http://example.org/flashtemplate.swt?type=gif�m1=v
al1�m2=
val2<http://example.org/flashtemplate.swt?type=gif�m1=val1�m2=val2> " alt="G
IF
Object Map of Alaska" WIDTHU0 HEIGHT35 border="0">
');
}
//-->
</SCRIPT>
// You will need to modify the SRC param as follows
<NOEMBED><IMG
SRC="http://example.org/flashtemplate.swt?type=gif�m1=val1�m2=val2
<http://example.org/flashtemplate.swt?type=gif�m1=val1�m2=val2> "
ALT="NOEMBED GIF Object Map of Alaska" WIDTHU0 HEIGHT35 usemap="#AK"
BORDER=0></NOEMBED>
// You will need to modify the SRC param as follows
<NOSCRIPT><IMG
SRC="http://example.org/flashtemplate.swt?type=gif�m1=val1�m2=val2
<http://example.org/flashtemplate.swt?type=gif�m1=val1�m2=val2> "
ALT="NOSCRIPT GIF Object Map of Alaska" WIDTHU0 HEIGHT35 usemap="#AK"
BORDER=0></NOSCRIPT>
_________________________________________________________________
Acknowledgments
Web Content Guidelines Working Group Co-Chairs:
Jason White, University of Melbourne
Gregg Vanderheiden, Trace Research and Development
W3C Team contact:
Wendy Chisholm
We wish to thank the following people who have contributed their time
and valuable comments to shaping this module:
Rob Neff
2 References
For the latest version of any W3C specification please consult the
list of W3C Technical Reports at http://www.w3.org/TR.
[WCAG10]
"Web Content Accessibility Guidelines 1.0", W. Chisholm, G.
Vanderheiden, and I. Jacobs, eds., 5 May 1999. This WCAG 1.0
Recommendation is
http://www.w3.org/TR/1999/WAI-WEBCONTENT-19990505.
[WCAG10-TECHS]
"Techniques for Web Content Accessibility Guidelines 1.0", W.
Chisholm, G. Vanderheiden, I. Jacobs, eds. This document
explains how to implement the checkpoints defined in "Web
Content Accessibility Guidelines 1.0". The latest draft of the
techniques is available at
http://www.w3.org/WAI/GL/WCAG10-TECHS/.
3 Resources
Note: W3C does not guarantee the stability of any of the following
references outside of its control. These references are included for
convenience. References to products are not endorsements of those
products.
3.1 Accessibility resources
@@Include relevant references to authoring for Flash
Level Triple-A conformance icon, W3C-WAI Web Content Accessibility
Guidelines 1.0
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