This is an unpublished draft preview that might include content that is not yet approved.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

Button has non-empty accessible name

Rule Type:
atomic
Rule ID:
97a4e1
Last Modified:
Oct 1, 2020
Accessibility Requirements Mapping:
4.1.2 Name, Role, Value (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
Input Aspects:
Accessibility Tree
DOM Tree
CSS Styling

Description

This rule checks that each button element has a non-empty accessible name.

Applicability

The rule applies to elements that are included in the accessibility tree and have a semantic role of button, except for input elements with a type attribute value of image.

Expectation

Each target element has an accessible name that is not empty ("").

Note: input elements with a type attribute value of either submit or reset can get their accessible name from a default text, as well as from a value or other attribute.

Assumptions

Accessibility Support

Background

Test Cases

Passed

Passed Example 1

This button element has an accessible name because of its text content.

<button>My button</button>

Passed Example 2

This input element has an accessible name because of its value attribute.

<input type="submit" value="Submit" />

Passed Example 3

This button element has an accessible name because of its aria-label attribute.

<button aria-label="My button"></button>

Passed Example 4

This element with a button role has an accessible name because of its aria-label attribute.

<span role="button" aria-label="My button"></span>

Passed Example 5

This button element with the disabled attribute has an accessible name because of its text content.

<button disabled>Delete</button>

Passed Example 6

This off screen button element has an accessible name because of its text content.

<html>
	<style>
		.notInPage {
			position: absolute;
			left: -9999px;
			top: -9999px;
		}
	</style>
	<body>
		<button class="notInPage">Save</button>
	</body>
</html>

Passed Example 7

This input element has an accessible name because of the default accessible name for an input element with a type attribute set to reset.

<input type="reset" />

Failed

Failed Example 1

This button element has no accessible name because it has no content or attribute that can provide it.

<button></button>

Failed Example 2

This button element has no accessible name. The value attribute does not provide an accessible name for button elements, only when an input element’s state of the type attribute is button, submit or reset.

<button type="button" value="read more"></button>

Failed Example 3

This element with the button role has no accessible name because it has no content or attribute that can provide it.

<span role="button"></span>

Failed Example 4

This off screen button element has no accessible name because it has no content or attribute that can provide it.

<html>
	<style>
		.notInPage {
			position: absolute;
			left: -9999px;
			top: -9999px;
		}
	</style>
	<body>
		<button class="notInPage" value="delete"></button>
	</body>
</html>

Failed Example 5

This button element has an explicit role of none. However, it is focusable (by default). Thus it has a semantic role of button due to Presentational Roles Conflict Resolution. It has an empty accessible name.

<button role="none"></button>

Inapplicable

Inapplicable Example 1

This input element has a type attribute set to image. These images are tested in a separate rule which also tests success criterion 1.1.1 Non-text Content.

<input type="image" value="download" alt="Download" />

Inapplicable Example 2

This button element does not need an accessible name because it is not included in the accessibility tree.

<button style="display: none;"></button>

Inapplicable Example 3

This button element has a link role. Links are tested in a separate rule which also tests success criterion 2.4.4 Link Purpose (In Context).

<button role="link">take me somewhere</button>

Inapplicable Example 4

There is no element with a semantic role of button.

<div>Press Here</div>

Inapplicable Example 5

This button element has an explicit role of none; it is not focusable because it is disabled. Thus it has a semantic role of none.

<button role="none" disabled></button>

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:

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

Elements that can become the target of keyboard input as described in the HTML specification of focusable and can be focused.

Hidden State

An HTML element’s hidden state is “true” if at least one of the following is true for itself or any of its ancestors in the flat tree:

In any other case, the element’s hidden state is “false”.

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. Elements in the accessibility tree are exposed to assistive technologies, allowing users to interact with the elements in a way that meet 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.

Note: Users of assistive technologies might still be able to interact with elements that are not included in the accessibility tree. An example of this is a focusable element with an aria-hidden attribute with a value of true. Such an element could still be interacted using sequential keyboard navigation regardless of the assistive technologies used, even though the element would not be included in the accessibility tree.

Marked as decorative

An element is marked as decorative if one 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 their hidden state is true. This is different from marking the element as decorative and does not convey the same intention. Notably, the hidden state of an element 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.

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.

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 its hidden state is false, 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.

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.

Acknowledgements

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

Authors

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/.