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Proposed Test Rule: meta element has no refresh delay

Applicability

This rule applies to the first meta element in a document for which all the following are true:

Expectation

For each test target, running the shared declarative refresh steps, given the target’s document, the value of the target’s content attribute, and the target results in time being either 0 or greater than 72000 (20 hours).

Assumptions

Accessibility Support

Not all major web browsers parse the value of the content attribute in the same way. Some major browsers, when they are unable to parse the value, default to a 0 seconds delay, whereas others will not redirect at all. This can cause some pages to be inapplicable for this rule, while still having a redirect in a minority of web browsers.

Background

This rule is designed specifically for 2.2.1 Timing Adjustable, which can be satisfied if the time limit is over 20 hours long. All pages that fail this because of a “refresh” meta element also do not satisfy 2.2.3 No Timing and 3.2.5 Change on Request. In order to adequately test the expectation, some of the passed examples do not satisfy 2.2.3 No Timing and 3.2.5 Change on Request.

Bibliography

Accessibility Requirements Mapping

Input Aspects

The following aspects are required in using this rule.

Test Cases

Passed

Passed Example 1

Redirects immediately.

<head>
	<meta http-equiv="refresh" content="0; URL='https://github.com'" />
</head>

Passed Example 2

First valid <meta http-equiv="refresh"> redirects immediately.

<head>
	<meta http-equiv="refresh" content="0; https://w3.org" />
	<meta http-equiv="refresh" content="5; https://w3.org" />
</head>

Passed Example 3

Redirects after more than 20 hours.

<head>
	<meta http-equiv="refresh" content="72001; https://w3.org" />
</head>

Failed

Failed Example 1

Refreshes after 30 seconds.

<head>
	<meta http-equiv="refresh" content="30" />
</head>

Failed Example 2

Redirects after 30 seconds.

<head>
	<meta http-equiv="refresh" content="30; URL='https://w3.org'" />
</head>

Failed Example 3

First <meta http-equiv="refresh"> element is not valid, second one redirects after 5 seconds.

<head>
	<meta http-equiv="refresh" content="0: https://w3.org" />
	<meta http-equiv="refresh" content="5; https://w3.org" />
</head>

Failed Example 4

Redirects after exactly 20 hours.

<head>
	<meta http-equiv="refresh" content="72000; https://w3.org" />
</head>

Inapplicable

Inapplicable Example 1

No content attribute.

<head>
	<meta http-equiv="refresh" />
</head>

Inapplicable Example 2

No http-equiv="refresh" attribute.

<head>
	<meta content="30" />
</head>

Inapplicable Example 3

content attribute is invalid and therefore inapplicable.

<head>
	<meta http-equiv="refresh" content="0: https://w3.org" />
</head>

Inapplicable Example 4

content attribute is invalid and therefore inapplicable.

<head>
	<meta http-equiv="refresh" content="-00.12 foo" />
</head>

Inapplicable Example 5

content attribute is invalid and therefore inapplicable.

<head>
	<meta http-equiv="refresh" content="; 30" />
</head>

Inapplicable Example 6

content attribute is invalid and therefore inapplicable.

<head>
	<meta http-equiv="refresh" content="" />
</head>

Inapplicable Example 7

content attribute is invalid and therefore inapplicable.

<head>
	<meta http-equiv="refresh" content="+5; https://w3.org" />
</head>

Inapplicable Example 8

content attribute is invalid and therefore inapplicable.

<head>
	<meta http-equiv="refresh" content="foo; URL='https://w3.org'" />
</head>

Glossary

Attribute value

The attribute value of a content attribute set on an HTML element is the value that the attribute gets after being parsed and computed according to specifications. It may differ from the value that is actually written in the HTML code due to trimming whitespace or non-digits characters, default values, or case-insensitivity.

Some notable case of attribute value, among others:

This list is not exhaustive, and only serves as an illustration for some of the most common cases.

The attribute value of an IDL attribute is the value returned on getting it. Note that when an IDL attribute reflects a content attribute, they have the same attribute value.

Outcome

An outcome is a conclusion that comes from evaluating an ACT Rule on a test subject or one of its constituent test target. An outcome can be one of the three following types:

Note: A rule has one passed or failed outcome for every test target. When there are no test targets the rule has one inapplicable outcome. This means that each test subject will have one or more outcomes.

Note: Implementations using the EARL10-Schema can express the outcome with the outcome property. In addition to passed, failed and inapplicable, EARL 1.0 also defined an incomplete outcome. While this cannot be the outcome of an ACT Rule when applied in its entirety, it often happens that rules are only partially evaluated. For example, when applicability was automated, but the expectations have to be evaluated manually. Such “interim” results can be expressed with the incomplete outcome.

Implementations

This section is not part of the official rule. It is populated dynamically and not accounted for in the change history or the last modified date.

Implementation Consistency Complete Report
Alfa Consistent No View Report
QualWeb Consistent No View Report
SortSite Consistent No View Report

Changelog

This is the first version of this ACT rule.

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