Element with presentational children has no focusable content

Description

This rule checks that elements with a role that makes its children presentational do not contain focusable elements.

Applicability

This rule applies to any HTML or SVG element with a semantic role that defines its children to be presentational children.

Expectation

None of the target elements have descendants in the flat tree that are part of sequential focus navigation.

Assumptions

This rule assumes that elements that are part of sequential focus navigation do not immediately blur, or move focus to another element. Such elements will fail this rule, but may still satisfy success criterion 4.1.2.

Accessibility Support

Several major browsers ignore the WAI-ARIA requirements on presentational children for most or sometimes all roles. Because some browsers do, and others do not implement presentational children, there can be significant differences between browsers.

Background

This rule applies to elements with a semantic role that defines its children to be presentational children, which are all of the following: button, checkbox, img, math, menuitemcheckbox, menuitemradio, option, progressbar, radio, scrollbar, separator, slider, switch, and tab.

Elements with a semantic role that has presentational children will not have any descendants in the accessibility tree. If any of those descendants are included in sequential focus navigation, this causes the focus to land on an element that has no corresponding node in the accessibility tree. The result is that there is no programmatic name or role available for assistive technologies. There are other problems that can come from presentational children too. These must be tested separately.

Related rules

• Element with aria-hidden has no focusable content

Bibliography

• Understanding Success Criterion 1.3.1: Info and Relationships
• Understanding Success Criterion 4.1.2: Name, Role, Value
• WAI-ARIA 1.1 Presentational Children
• Element with aria-hidden has no focusable content

Accessibility Requirements Mapping

• 4.1.2 Name, Role, Value (Level A)

  • Learn more about 4.1.2 Name, Role, Value
  • 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

Input Aspects

The following aspects are required in using this rule.

• DOM Tree
• CSS Styling

Test Cases

Passed

Passed Example 1

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None of these button elements has descendants that are included in sequential focus navigation.

<button>Save</button> <button aria-label="save options" aria-expanded="false">▼</button>

Passed Example 2

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This element with checkbox role has no descendants that are included in sequential focus navigation. Instead the link to the terms of service is adjacent, and aria-labelledby is used to provide its accessible name.

<p id="terms">
	<span role="checkbox" aria-checked="false" tabindex="0" aria-labelledby="terms">
		I agree to the
	</span>
	<a href="/terms">terms of service</a>
</p>

Passed Example 3

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This element with menuitemcheckbox role has an input element as a descendant. Because the input is disabled it is not included in sequential focus navigation.

Note: The input checkbox has a role attribute value of none to ensure it is ignored by browsers that do not support presentational children.

<ul role="menu">
	<li role="menuitemcheckbox" aria-checked="true">
		<input type="checkbox" role="none" disabled checked />
		Sort by Last Modified
	</li>
</ul>

Failed

Failed Example 1

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This button element has a child span element. Because the span element has a tabindex attribute with value of 0, it is included in sequential focus navigation.

<button>
	Save
	<span role="button" aria-label="save options" aria-expanded="false" tabindex="0">▼</span>
</button>

Failed Example 2

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This element with checkbox role has an a element as a child. Because the a element has an href attribute, it is included in sequential focus navigation.

<p role="checkbox" aria-checked="false" tabindex="0">I agree to the <a href="/terms">terms of service</a></p>

Failed Example 3

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This element with menuitemcheckbox role has a checkbox as a child. Because the checkbox is not disabled, it is included in sequential focus navigation.

<ul role="menu">
	<li role="menuitemcheckbox" aria-checked="true">
		<input type="checkbox" checked />
		Sort by Last Modified
	</li>
</ul>

Inapplicable

Inapplicable Example 1

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This element has a link role which does not have presentational children.

<a href="https://w3.org">W3C Website</a>

Glossary

Accessible Name

The accessible name is the programmatically determined name of a user interface element that is included in the accessibility tree.

The accessible name is calculated using the accessible name and description computation.

For native markup languages, such as HTML and SVG, additional information on how to calculate the accessible name can be found in HTML Accessibility API Mappings 1.0, Accessible Name and Description Computation (working draft) and SVG Accessibility API Mappings, Name and Description (working draft).

For more details, see examples of accessible name.

Note: As per the accessible name and description computation, each element always has an accessible name. When no accessible name is provided, the element will nonetheless be assigned an empty ("") one.

Note: As per the accessible name and description computation, accessible names are flat string trimmed of leading and trailing whitespace. Notably, it is not possible for a non-empty accessible name to be composed only of whitespace since these must be trimmed.

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:

• For enumerated attributes, the attribute value is either the state of the attribute, or the keyword that maps to it; even for the default states. Thus <input type="image" /> has an attribute value of either Image Button (the state) or image (the keyword mapping to it), both formulations having the same meaning; similarly, “an input element with a type attribute value of Text” can be either <input type="text" />, <input /> (missing value default), or <input type="invalid" /> (invalid value default).
• For boolean attributes, the attribute value is true when the attribute is present and false otherwise. Thus <button disabled>, <button disabled="disabled"> and <button disabled=""> all have a disabled attribute value of true.
• For attributes whose value is used in a case-insensitive context, the attribute value is the lowercase version of the value written in the HTML code.
• For attributes that accept numbers, the attribute value is the result of parsing the value written in the HTML code according to the rules for parsing this kind of number.
• For attributes that accept sets of tokens, whether space separated or comma separated, the attribute value is the set of tokens obtained after parsing the set and, depending on the case, converting its items to lowercase (if the set is used in a case-insensitive context).
• For aria-* attributes, the attribute value is computed as indicated in the WAI-ARIA specification and the HTML Accessibility API Mappings.

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.

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:

• the element is part of sequential focus navigation; or
• the element has a tabindex value that is not null.

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:

• The 1 second time span is an arbitrary limit which is not included in WCAG. Given that scripts can manage the focus state of elements, testing the focusability of an element consistently would be impractical without a time limit.
• The tabindex value of an element is the value of the tabindex attribute parsed using the rules for parsing integers. For the tabindex value to be different from null, it needs to be parsed without errors.

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:

• it has an explicit role of none or presentation; or
• it is an img element with an alt attribute whose value is the empty string (alt=""), and with no explicit role.

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:

• 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.

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:

• has a computed CSS property display of none; or
• has an aria-hidden attribute set to true

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

Note: The HTML standard suggests setting the CSS display property to none for elements with the hidden attribute. While not required by HTML, all modern browsers follow this suggestion. Because of this the hidden attribute is not used in this definition. In browsers that use this suggestion, overriding the CSS display property can reveal elements with the hidden attribute.

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:

• Accessible Rich Internet Applications (WAI-ARIA) 1.1
• WAI-ARIA Graphics Module 1.0
• Digital Publishing WAI-ARIA Module 1.0

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

Rule Versions

1. Latest version, 23 June 2022

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	Type	Consistency	Report
Alfa (fully automated) 0.57.2	Automated tool	Consistent
Alfa (semi-automated) 0.57.2	Semi-automated tool	Consistent
Axe DevTools Pro 4.37.1	Semi-automated tool	Consistent
Axe-core 4.6.0	Automated tool	Consistent
Equal Access Accessibility Checker 3.1.42-rc.0	Automated tool	Consistent
QualWeb 3.0.0	Automated tool	Consistent
SortSite 6.45	Automated tool	Consistent
Total Validator 17.1.0	Linter	Consistent
Total Validator (+Browser) 17.1.0	Automated tool	Consistent