Techniques for WCAG 2.0

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# G76: Providing a mechanism to request an update of the content instead of updating automatically

## Applicability

Any technology or combination of technologies that support automatic updates.

This technique relates to:

- Success Criterion 3.2.5 (Change on Request)
  - How to Meet 3.2.5 (Change on Request)
  - Understanding Success Criterion 3.2.5 (Change on Request)

## Description

The objective of this technique is to let the user control if and when content is updated, in order to avoid confusion or disorientation caused by automatic refreshes that cause a change of context. Users of screen readers may find automatic updates confusing because it is not always clear what is happening. When a page is refreshed, the screen reader's “virtual cursor", which marks the user's current location on the page, is moved to the top of the page. People who use screen magnification software and people with reading disabilities may also be disoriented when pages are refreshed automatically.

Some content is frequently updated with new data or information. Some developers force automatic updates by inserting code in the content that causes the content to request a new copy of itself from the server. These updates and the frequency of these updates are not always under the user's control. Instead of triggering updates automatically, authors can provide a mechanism that allows the user to request an update of the content as needed.

## Examples

### Example 1

In HTML, a developer can provide a button or link that allows the user to update the content. For example, on a page with news items located at http://www.example.com/news.jsp

Example Code:

    <a href="news.jsp">Update this page</a>

### Example 2

In a Web interface for e-mail (Webmail), a developer can provide a button or link to fetch new incoming mails instead of updating automatically.

## Resources

Resources are for information purposes only, no endorsement implied.

- Time outs and page refreshes, by the Web Access Centre of the Royal National Institute of the Blind (RNIB), provides rationale and techniques.

## Related Techniques

- G75: Providing a mechanism to postpone any updating of content
- SCR14: Using scripts to make nonessential alerts optional

## Tests

### Procedure

1. Find mechanisms to update the content (if such a mechanism is present).

2. For each such mechanism, check if it allows the user to request an update.

3. For each such mechanism, check if it can cause an automatic update.

### Expected Results

- If #2 is true, then #3 is false.

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