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Proposed Test Rule: Element with role attribute has required states and properties

Applicability

This rule applies to any HTML or SVG element that is included in the accessibility tree and has an explicit semantic role, except if the element has an implicit semantic role that is identical to the explicit semantic role.

Expectation

For each test target, the WAI-ARIA required states and properties for the role are set and not empty (""), unless the state or property has a default value listed under WAI-ARIA implicit value for role.

Note: In WAI-ARIA 1.2, required states and properties will no longer have a default value.

Assumptions

Accessibility Support

This rule relies on browsers and assistive technologies to support leaving out WAI-ARIA required states and properties when a WAI-ARIA implicit value for role is specified in WAI-ARIA Specifications.

Note: The required states and properties with implicit values can be found in the Core Accessibility API Mappings 1.1 Overview of default values for missing required attributes.

Background

Bibliography

Accessibility Requirements Mapping

Input Aspects

The following aspects are required in using this rule.

Test Cases

Passed

Passed Example 1

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This checkbox has the required property aria-checked.

<div role="checkbox" aria-checked="false"></div>

Passed Example 2

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This scrollbar has the required properties aria-controls and aria-valuenow. aria-valuemin has a default value of 0 and aria-valuemax of 100.

<div role="scrollbar" aria-controls="content" aria-valuenow="0"></div>
<main id="content"></main>

Passed Example 3

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This combobox has required properties aria-controls and aria-expanded. aria-controls references an element that does not exist, but may be added to the page when expanded.

<div role="combobox" aria-controls="someElementId" aria-expanded="false"></div>

Failed

Failed Example 1

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This combobox is missing the required aria-controls property.

Note: In WAI-ARIA 1.2, combobox will also require aria-expanded.

<div role="combobox" aria-expanded="true"></div>

Failed Example 2

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This combobox has an empty value for the required aria-controls property.

<div role="combobox" aria-controls="" aria-expanded="true"></div>

Inapplicable

Inapplicable Example 1

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This div does not have a semantic role.

<div>Some Content</div>

Inapplicable Example 2

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This checkbox has an implicit semantic role that is identical to the explicit semantic role.

<input type="checkbox" role="checkbox" />

Inapplicable Example 3

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This combobox is not included in the accessibility tree due to its styling, hiding it from everybody.

<div role="combobox" style="display:none;"></div>

Glossary

Explicit Semantic Role

The explicit semantic role of an element is determined by its role attribute (if any).

The role attribute takes a list of tokens. The explicit semantic role is the first valid role in this list. The valid roles are all non-abstract roles from WAI-ARIA Specifications. If the element has no role attribute, or if it has one with no valid role, then this element has no explicit semantic role.

Other roles may be added as they become available. Not all roles will be supported in all assistive technologies. Testers are encouraged to adjust which roles are allowed according to the accessibility support base line. For the purposes of executing test cases in all rules, it should be assumed that all roles are supported by assistive technologies so that none of the roles fail due to lack of accessibility support.

Focusable

An element is focusable if one or both of the following are true:

Exception: Elements that lose focus during a period of up to 1 second after gaining focus, without the user interacting with the page the element is on, are not considered focusable.

Notes:

Implicit Semantic Role

The implicit semantic role of an element is a pre-defined value given by the host language which depends on the element and its ancestors.

Implicit roles for HTML and SVG, are documented in the HTML accessibility API mappings (working draft) and the SVG accessibility API mappings (working draft).

Included in the accessibility tree

Elements included in the accessibility tree of platform specific accessibility APIs are exposed to assistive technologies. This allows users of assistive technology to access the elements in a way that meets the requirements of the individual user.

The general rules for when elements are included in the accessibility tree are defined in the core accessibility API mappings. For native markup languages, such as HTML and SVG, additional rules for when elements are included in the accessibility tree can be found in the HTML accessibility API mappings (working draft) and the SVG accessibility API mappings (working draft).

For more details, see examples of included in the accessibility tree.

Programmatically hidden elements are removed from the accessibility tree. However, some browsers will leave focusable elements with an aria-hidden attribute set to true in the accessibility tree. Because they are hidden, these elements are considered not included in the accessibility tree. This may cause confusion for users of assistive technologies because they may still be able to interact with these focusable elements using sequential keyboard navigation, even though the element should not be included in the accessibility tree.

Marked as decorative

An element is marked as decorative if one or more of the following conditions is true:

Elements are marked as decorative as a way to convey the intention of the author that they are pure decoration. It is different from the element actually being pure decoration as authors may make mistakes. It is different from the element being effectively ignored by assistive technologies as rules such as presentational roles conflict resolution may overwrite this intention.

Elements can also be ignored by assistive technologies if they are programmatically hidden. This is different from marking the element as decorative and does not convey the same intention. Notably, being programmatically hidden may change as users interact with the page (showing and hiding elements) while being marked as decorative should stay the same through all states of the page.

Namespaced Element

An element with a specific namespaceURI value from HTML namespaces. For example an “SVG element” is any element with the “SVG namespace”, which is http://www.w3.org/2000/svg.

Namespaced elements are not limited to elements described in a specification. They also include custom elements. Elements such as a and title have a different namespace depending on where they are used. For example a title in an HTML page usually has the HTML namespace. When used in an svg element, a title element has the SVG namespace instead.

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.

Programmatically Hidden

An HTML element is programmatically hidden if either it has a computed CSS property visibility whose value is not visible; or at least one of the following is true for any of its inclusive ancestors in the flat tree:

Note: Contrarily to the other conditions, the visibility CSS property may be reverted by descendants.

Note: The HTML standard suggests rendering elements with the hidden attribute with a CSS rule that applies the value none to the CSS property display of the element. Although the suggestion is not normative, known user agents render it according to the suggestion (unless the content specifies another CSS rule that sets the value of the display property). If a user agent does not follow the suggestion, this definition may produce incorrect results for this user agent.

Semantic Role

The semantic role of an element is determined by the first of these cases that applies:

  1. Conflict If the element is marked as decorative, but the element is included in the accessibility tree; or would be included in the accessibility tree when it is not programmatically hidden, then its semantic role is its implicit role.
  2. Explicit If the element has an explicit role, then its semantic role is its explicit role.
  3. Implicit The semantic role of the element is its implicit role.

This definition can be used in expressions such as “semantic button” meaning any element with a semantic role of button.

WAI-ARIA specifications

The WAI ARIA Specifications group both the WAI ARIA W3C Recommendation and ARIA modules, namely:

Note: depending on the type of content being evaluated, part of the specifications might be irrelevant and should be ignored.

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
QualWeb Consistent Yes View Report
SortSite Consistent No View Report

Changelog

This is the first version of this ACT rule.

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This is an unpublished draft preview that might include content that is not yet approved. The published website is at w3.org/WAI/.