HTML page has lang attribute

Rule Type:

atomic

Rule ID:

b5c3f8

Last Modified:

March 5, 2020

Accessibility Requirements Mapping:

3.1.1 Language of Page (Level A)

Required for conformance to WCAG 2.0 and later on level A and higher
Outcome mapping:
- Any failed outcomes: success criterion is not satisfied
- All passed outcomes: success criterion needs further testing
- An inapplicable outcome: success criterion needs further testing

H57: Using language attributes on the html element

Not required to conformance to any W3C accessibility recommendation.
Outcome mapping:
- Any failed outcomes: technique is not satisfied
- All passed outcomes: technique needs further testing
- An inapplicable outcome: technique needs further testing

Input Aspects:

DOM Tree

Description

This rule checks that an HTML page has a non-empty lang attribute.

Applicability

This rule applies to any document element if it is an html element that:

is in a top-level browsing context; and
has a node document with a content type of text/html.

Note: html elements within iframe and object elements are not applicable as iframe and object elements create nested browsing contexts. However, as these elements are meant to provide a layer of isolation, the declared language of their parent browsing context will likely not be inherited, making it possible for empty lang attributes in nested browsing contexts to also cause accessibility issues.

Expectation

Each test target has a lang attribute that is neither empty ("") nor only ASCII whitespace.

Assumptions

The language of the page can be set by other methods than the lang attribute, for example using HTTP headers or the meta element. These methods are not supported by all assistive technologies. This rule assumes that these other methods are insufficient to satisfying Success Criterion 3.1.1: Language of Page.

Accessibility Support

There are no major accessibility support issues known for this rule.

Background

Test Cases

Passed

Passed Example 1

This html element has a lang attribute with a non-empty ("") value.

<html lang="en"></html>

Failed

Failed Example 1

This html element does not have a lang attribute.

<html></html>

Failed Example 2

This html element has a lang attribute with an empty ("") value.

<html lang=""></html>

Failed Example 3

This html element has a lang attribute whose value is only ASCII whitespace.

<html lang=" "></html>

Failed Example 4

This html element has no lang attribute, only a xml:lang attribute.

<html xml:lang="en"></html>

Inapplicable

Inapplicable Example 1

This rule does not apply to svg element.

<svg xmlns="http://www.w3.org/2000/svg"></svg>

Inapplicable Example 2

This rule does not apply to math element.

<math></math>

Glossary

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:

Inapplicable: No part of the test subject matches the applicability
Passed: A test target meets all expectations
Failed: A test target does not meet all expectations

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.

Acknowledgements

This rule was written in the ACT Rules community group, with the support of the EU-funded WAI-Tools Project.

Authors

Jey Nandakumar

Previous Authors

Annika Nietzio

Changelog

This is the first version of this ACT rule.