Re: [orca-list] ajax

[Benjamin Hawkes-Lewis <bhawkeslewis googlemail com>]

On Sun, Dec 12, 2010 at 9:18 AM, Michal Zegan
<webczat_200 poczta onet pl> wrote:
> What problems can blind users using any screenreader (orca too) with webpages using ajax/js?
> I read that they can be inaccessible but can't I just read them when they change or so?

This is a large and extremely complicated topic.

JS is a scripting language. Browsers provide a series of interfaces
that JS developers can use for manipulating documents, images,
windows, forms, frames, etc.

AJAX is a style of using JS to refresh a webpage continuously based on
user interaction and background updates:

http://www.adaptivepath.com/ideas/essays/archives/000385.php

There are three things that can fail when JS is used to refresh a page:

   1. The JS might add controls or content that is not accessible to
screen readers.
   2. The chains of communication between the browser and the screen
reader might fail such that the screen reader's rendering of the page
might not update.
   3. The screen reader's rendering of the page might update without
the user being made notified of critical updates.

There are other aspects of the use of JS that can also make
accessibility problems, but aren't properly speaking part of the AJAX
style. For example, JS might be used to trigger critical functionality
based on mouse activity alone, without providing a device independent
way of triggering the same functionality that could be accessed from a
keyboard.

--
Benjamin Hawkes-Lewis