JAVASCRIPT Techniques
for Web Content Accessibility Guidelines

W3C Internal Working Draft

Editors:

Wendy Chisholm, Trace R & D Center, University of Wisconsin -- Madison

Katie Haritos-Shea, Paradigm Solutions Corp. & NTIS - US Dept. of Commerce

Abstract

This document describes techniques for creating accessible Javascript content. This document is intended to help authors of Web content who wish to claim conformance to "Web Content Accessibility Guidelines 1.0" ([WCAG10]).

For each technique, we identify the version of Javascript in which the language support is first available. Where no version is specified, the technique can be applied in all versions of Javascript.

This document is part of a series of documents about techniques for authoring accessible Web content. For information about the other documents in the series, please refer to "Techniques for Web Content Accessibility Guidelines 1.0" WCAG 1.0

JAVASCRIPT

Design content that allows presentation according to the user's needs and preferences

Checkpoint 1.1 Provide a text equivalent for all non-text content.

Provide a valid "alt" attribute for every img element.

A valid "alt" attribute provides a short functional equivalent for an image. A long description may also be necessary (see item 2). A valid "alt" attribute:

• May be "" or " " for spacer images and not in an A element. [refer author to browser support to help them make a decision - ala the decision at the 15 June 2000 teleconference]
• Should not contain the size of the file (e.g., "780K")
• Should not contain the file name (e.g., "foo.gif")
• Should not contain placeholder text (e.g., "put alt-text here")
• May be a "*" for bullets in a list (although style sheets are the recommended way of doing this. [refer to CSS techniques and browser support]
• May be.... [continue to document standard alt-text practices]
• For an applet...
• For a graphical input button...

Describe an image if the description will add information not given in the text or short equivalent required in #1.

The amount of information contained in the illustration will determine how detailed your description must be. Images that usually require a description are diagrams, charts, and maps. [refer to excerpts from NBA manual on examples and directions for describing images]

Provide a valid "alt" attribute for every input element of type="image".

[provide description similar to #1]

Provide a valid "alt" attribute for every applet element

A valid "alt" attribute:

• [provide description similar to #1]

Describe an applet if the description will add information not given in the text or short equivalent required in #4

[similar to the nesting objects phenomenon]

Provide an HTML equivalent of an applet if the page is unusable without one

(i.e. the applet is interactive and the interaction is required to progress throughout the site or application).

Provide a valid text equivalent within the content of an object element.

[Need to distinguish between images, movies, etc. Also discuss cascade of alternatives. Similar structure as with applets (#4-6)?]

Provide a text transcript of all audio files

[refer to core techniques]

Describe the relationships between frames if the relationships are not apparent from the titles of the pages in the frames

Link to this description using the "longdesc" attribute on each of the frame elements.

Provide a valid "alt" attribute for every area element

A valid "alt" attribute...

Script elements...

aye yi yi.

Use valid HTML to provide a text equivalent and perhaps describe ASCII art

[link to a description?]

Design content that allows interaction according to the user's needs and preferences

Design for ease of comprehension

Design for compatability and interoperability

JAVASCRIPT Glossary

$Date: 2001/03/15 21:39:05 $ Wendy Chisholm

Date: 2001/03/15 Katie Haritos-Shea