Button has non-empty accessible name
Description
This rule checks that each button
element has a non-empty accessible name.
Applicability
This 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 (""
).
Assumptions
- The rule assumes that all buttons are user interface components as defined by WCAG 2.
Accessibility Support
-
Implementation of Presentational Roles Conflict Resolution varies from one browser or assistive technology to another. Depending on this, some elements can have a semantic role of
button
and fail this rule with some technology but users of other technologies would not experience any accessibility issue. -
Some elements have a role of
button
and a default accessible name defined by the HTML Accessibility API Mapping, for exampleinput
elements whosetype
attribute value is eithersubmit
orreset
. This rule considers that these default names can be descriptive and therefore does not fail them.
Background
This rule considers an exception for “image buttons” (i.e., input
elements with a type
attribute value of image
). Image buttons failing this rule would fail Success Criterion 4.1.2 and Success Criterion 1.1.1 which is not part of the accessibility requirements for this rule.
Related rules
Bibliography
- HTML Accessibility API Mappings 1.0 (working draft), 5.2
input type="button"
,input type="submit"
andinput type="reset"
- Understanding Success Criterion 4.1.2: Name, Role, Value
- ARIA14: Using aria-label to provide an invisible label where a visible label cannot be used
- ARIA16: Using aria-labelledby to provide a name for user interface controls
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
- Any
Input Aspects
The following aspects are required in using this rule.
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:
- 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 eitherImage Button
(the state) orimage
(the keyword mapping to it), both formulations having the same meaning; similarly, “an input element with atype
attribute value ofText
” 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 andfalse
otherwise. Thus<button disabled>
,<button disabled="disabled">
and<button disabled="">
all have adisabled
attribute value oftrue
. - 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
orpresentation
; or - it is an
img
element with analt
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.
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
ofnone
; or - has an
aria-hidden
attribute set totrue
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:
- 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.
- Explicit If the element has an explicit role, then its semantic role is its explicit role.
- 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
-
Latest version, 31 August 2023
(compare)
- Update to reference ARIA 1.2
-
Previous version, 23 June 2022
(compare)
- Account for focus redirects in "focusable" definition
- Let hidden attribute be handled by display:none in "programmatically hidden" definition
- Previous version, 28 January 2022