See Understanding Techniques for WCAG Success Criteria for important information about the usage of these informative techniques and how they relate to the normative WCAG 2.0 success criteria. The Applicability section explains the scope of the technique, and the presence of techniques for a specific technology does not imply that the technology can be used in all situations to create content that meets WCAG 2.0.
HTML and XHTML
This failure relates to:
meta
http-equiv of refresh is often used to periodically refresh
pages or to redirect users to another page. If the time interval is too
short, and there is no way to turn auto-refresh off, people who are blind will not have enough time to make their screen
readers read the page before the page refreshes unexpectedly and causes the
screen reader to begin reading at the top. Sighted users may also be
disoriented by the unexpected refresh.
This is a deprecated example that changes the user's page at regular
intervals. Content developers should not use this technique to
simulate "push" technology. Developers cannot predict how much time
a user will require to read a page; premature refresh can disorient
users. Content developers should avoid periodic refresh and allow
users to choose when they want the latest information. (The number
in the content attribute is the refresh interval in
seconds.)
Example Code:
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>HTML Techniques for WCAG 2.0</title>
<meta http-equiv="refresh" content="60" />
</head>
<body>
...
</body>
</html>
This is a deprecated example that redirects the user to another page
after a number of seconds. Content developers are recommended to
user server-side redirects instead. (The number in the
content attribute is the refresh interval in
seconds.)
Example Code:
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>The Tudors</title>
<meta http-equiv="refresh" content="10;URL='http://example.com/'" />
</head>
<body>
<p>This page has moved to a <a href="http://example.com/">
example.com</a>. Please note that we now have our own
domain name and will redirect you in a few seconds. Please update
your links and bookmarks.</p>
</body>
</html> Find meta elements in the document.
For each meta element, check if it contains the
attribute http-equiv with value "refresh"
(case-insensitive) and the content attribute with a
number (representing seconds) greater than 0.
check to see if there is a mechanism to turn off the refresh.
If step 2 is true and step 3 is false then this failure condition applies and content fails these Success Criteria.