Image button has non-empty accessible name
Description
This rule checks that each image button element has a non-empty accessible name.
Applicability
This rule applies to any input
element with a type
attribute value of image
, and that is included in the accessibility tree.
Expectation
Each target element has an accessible name that is neither empty (""
), nor the default name for this element (localized version of “Submit Query”).
Assumptions
- This rule assumes that all image buttons are user interface components as defined by WCAG 2.
- This rule assumes that the default name for image buttons (“Submit Query”), as defined by the HTML Accessibility API Mapping, is never descriptive.
Accessibility Support
There is a known combination of a popular browser and assistive technology that does not by default support title
as an accessible name.
Background
Related rules
Bibliography
- Understanding Success Criterion 1.1.1: Non-text Content
- Understanding Success Criterion 4.1.2: Name, Role, Value
- WCAG Technique H36: Using alt attributes on images used as submit buttons
- HTML Accessibility API Mappings for computing the accessible name of image buttons
Accessibility Requirements Mapping
1.1.1 Non-text Content (Level A)
- Learn more about 1.1.1 Non-text Content
- 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
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
G94: Providing short text alternative for non-text content that serves the same purpose and presents the same information as the non-text content
- Learn more about technique G94
- Not required for 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
- Any
G95: Providing short text alternatives that provide a brief description of the non-text content
- Learn more about technique G95
- Not required for 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
- Any
Input Aspects
The following aspects are required in using this rule.
Test Cases
Passed
Passed Example 1
The image button has an accessible name through the alt
attribute.
<input type="image" src="/test-assets/shared/search-icon.svg" alt="Search" />
Passed Example 2
The image button has an accessible name through the aria-label
attribute.
<input type="image" src="/test-assets/shared/search-icon.svg" aria-label="Search" />
Passed Example 3
The image button has an accessible name through the title
attribute.
note: The title
attribute may not always be accessibility supported.
<input type="image" src="/test-assets/shared/search-icon.svg" title="Search" />
Passed Example 4
The image button has an accessible name through the aria-labelledby
attribute.
<input type="image" src="/test-assets/shared/search-icon.svg" aria-labelledby="id1" />
<div id="id1">Search</div>
Failed
Failed Example 1
The image button element has an accessible name equal to the default “Submit Query”. The name
attribute can not be used to provide an accessible name.
<input type="image" name="search" src="/test-assets/shared/search-icon.svg" />
Failed Example 2
The image button has an empty alt
attribute, and no other attributes that can give it an accessible name, hence its name is the default “Submit Query”.
<input type="image" src="/test-assets/shared/search-icon.svg" alt="" />
Failed Example 3
The image button has an aria-labelledby
attribute, but the referenced element does not exist. This gives the button the default accessible name of “Submit Query”.
<input type="image" src="/test-assets/shared/search-icon.svg" aria-labelledby="non-existing" />
Inapplicable
Inapplicable Example 1
The button
element is not an image button. Success Criterion 1.1.1 Non-text Content can not fail text buttons. Only non-text content is applicable.
<button>My button</button>
Inapplicable Example 2
The input
element with the type
attribute value of button
is not an image button. Success Criterion 1.1.1 Non-text Content can not fail text buttons. Only non-text content is applicable.
<input type="button" value="My button" />
Inapplicable Example 3
The button
element is tested separately from the img
element. Success Criterion 4.1.2 Name, Role, Value is applied to the button, whereas the image is tested under Success Criterion 1.1.1 Non-text Content
<button><img src="/test-assets/shared/search-icon.svg" alt="Search" /></button>
Inapplicable Example 4
The img
element is not a user interface component, and so is not tested for Success Criterion 4.1.2 Name, Role, Value.
<img src="/test-assets/shared/w3c-logo.png" alt="W3C logo" />
Inapplicable Example 5
The image button is ignored by assistive technologies because it is not included in the accessibility tree. These are not required to have an accessible name. If at some future state of the page the element gets included in the accessibility tree, an accessible name will be necessary.
<input type="image" src="/test-assets/shared/search-icon.svg" style="display: none;" />
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.
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.
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.
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.
Rule Versions
-
Latest version, 31 August 2023
(compare)
- Add clarification about empty attributes to Background and Accessibility support
-
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