13.1 Pages usable when scripts applets and other programmatic objects turned off
The New Zealand Web Standards 2.0 were released in March 2009 and replace the previous version, the New Zealand Government Web Standards 1.0 (below). See Meeting the standards for more information.
The Standard
13.1 Ensure that pages are usable when scripts, applets, or other programmatic objects are turned off or not supported. If this is not possible, provide equivalent information on an alternative accessible page.
Guide to this standard
Scripting as referred to here is Client-side scripting.
Scripting languages should only be used where required. A simple rule of thumb regarding the usage of scripting or applets is to ask:
- "Is this really necessary in the web site?" and
- "Can the functional end objective be met without scripting and/or applets?"
If scripting (or an applet) must be used, then:
- All information and services on a government web site must be available whether or not scripting is available to the user, and
- Text-based alternatives are available.
- If using Javascript, adopt the principals of "unobtrusive Javascript". This is principally enhancing usability without decreasing accessibility with the use of Javascript.
Where active scripting is used, it should conform to the ECMAScript standard, rather than a proprietary standard, and should use the W3C Document Object Model (DOM). This is a platform- and language-neutral interface that will allow programs and scripts to dynamically access and update the content, structure and style of documents.
This standard covers the W3C WAI checkpoint 6.3 for NZ government agencies.
Rationale for this standard
Some organisations and individuals do not allow scripts to be run in their browsers, and some browsers do not understand some types of scripting. Scripting languages (particularly JavaScript) are abused creating a perception of insecurity and/or invasiveness among some web users.
Scripting can reduce accessibility in certain circumstances and can 'confuse' assistive technologies such as screen readers. Dynamic drop-down menus in particular are known to cause significant accessibility problems for people with motor or visual impairments, for example when screen magnifiers are used.
Applets and/or support for applets may require downloads, which are either disabled for a user community or which a user simply may not wish to download (and run through possible subsequent installations) for one or more reasons (excessive time to download with a slow connection, potential security issues etc.)
A web browser user generally has full control over any client-side scripting, giving the potential for manipulation of the script.
Most browsers provide a means to disable support for scripting, thus reinforcing the need not to have reliance on scripting.
