Proposed Test Rule: Visible label is part of accessible name
Description
This rule checks that interactive elements labeled through content have their visible label as part of their accessible name.
Applicability
This rule applies to any element for which all the following is true:
- The element has a semantic role that is a widget that supports name from content; and
- The element has visible text content; and
- The element has an
aria-label
oraria-labelledby
attribute.
Expectation
For each target element, all text nodes in the visible text content either match or are contained within the accessible name of this target element, except for characters in the text nodes used to express non-text content. Leading and trailing whitespace and difference in case sensitivity should be ignored.
Assumptions
There are currently no assumptions
Accessibility Support
Implementation of Presentational Roles Conflict Resolution varies from one browser or assistive technology to another. Depending on this, some elements can have one of the applicable semantic roles and fail this rule with some technology but users of other technologies would not experience any accessibility issue.
Background
This rule applies to elements with a widget role that support name from content. This includes the following: button
, checkbox
, gridcell
, link
, menuitem
, menuitemcheckbox
, menuitemradio
, option
, radio
, searchbox
, switch
, tab
, treeitem
.
The understanding document of 2.5.3 Label in Name use the term “symbolic text characters” to refer to a type of non-text content that uses text characters as symbols, such as using “x” to mean “close”. This rule considers them as “characters expressing non-text content”. Unicode emojis are another example of characters expressing non-text content, although these are not “symbolic text characters”.
- Understanding Success Criterion 2.5.3: Label in Name
- G208: Including the text of the visible label as part of the accessible name
Test Cases
Passed
Passed Example 1
This link has visible text that matches the accessible name.
<a href="https://act-rules.github.io/" aria-label="ACT rules">ACT rules</a>
Passed Example 2
This link has visible text that, ignoring trailing whitespace, matches the accessible name.
<a href="https://act-rules.github.io/" aria-label=" ACT rules ">ACT rules</a>
Passed Example 3
This link has visible text that, ignoring case, matches the accessible name.
<a href="https://act-rules.github.io/" aria-label="act rules">ACT rules</a>
Passed Example 4
This button has visible text that is contained within the accessible name.
<button aria-label="Next Page in the list">Next Page</button>
Passed Example 5
This button has visible text that does not need to be contained within the accessible name, because the “x” text node is non-text content.
<button aria-label="close">X</button>
Passed Example 6
This button
element has the text “search” rendered as an magnifying glass icon by the font. Because the text is rendered as non-text content, the text does not need to be contained within the accessible name.
<link href="https://fonts.googleapis.com/icon?family=Material+Icons" rel="stylesheet" />
<style>
button {
font-family: 'Material Icons';
}
</style>
<button aria-label="Find">search</button>
Failed
Failed Example 1
This link has visible text that is different from the accessible name.
<a href="https://act-rules.github.io/" aria-label="WCAG">ACT rules</a>
Failed Example 2
This button has visible text that is only partially contained within the accessible name.
<button aria-label="the full">The full label</button>
Failed Example 3
This link has visible text with mathematical symbols, that does not match the accessible name because the mathematical symbols were written out in the accessible name. This is explicitly mentioned in WCAG.
<a href="/" aria-label="Proof of two multiplied by two is four">Proof of 2×2=4</a>
Inapplicable
Inapplicable Example 1
This nav
is not a widget, so the visible text does not need to match the accessible name.
<nav aria-label="main nav">W3C navigation</nav>
Inapplicable Example 2
This email text field does not need to have its visible text match the accessible name. The content of a textfield shows its value instead of its label; it does not support name from content. The label is usually adjacent to the textfield instead.
<div>E-mail</div>
<input type="email" aria-label="E-mail" value="Contact" />
Inapplicable Example 3
This div
element does not have a widget role, so the visible text does not need to match the accessible name.
<div role="tooltip" aria-label="OK">Next</div>
Inapplicable Example 4
This link has no visible text content.
<a href="https://w3.org" aria-label="W3C homepage">
<img src="/test-assets/shared/w3c-logo.png" alt="w3c logo" />
</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.
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:
- has a
hidden
attribute; or - has a computed CSS property
display
ofnone
; or - has a computed CSS property
visibility
ofhidden
; or - has an
aria-hidden
attribute set totrue
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.
[examples of included in the accessibility tree]: https://act-rules.github.io/pages/examples/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 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:
- 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.
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 its hidden state is false, 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.
Visible
Content perceivable through sight.
Content is considered visible if making it fully transparent would result in a difference in the pixels rendered for any part of the document that is currently within the viewport or can be brought into the viewport via scrolling.
For more details, see examples of visible.
Visible Text Content
The visible text content of an element is a set of all visible text nodes that are descendants in the flat tree of this element
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.
Whitespace
Whitespace are characters that have the Unicode “White_Space” property in the Unicode properties list.
This includes:
- all characters in the Unicode Separator categories, and
-
the following characters in the Other, Control category:
- Character tabulation (U+0009)
- Line Feed (LF) (U+000A)
- Line Tabulation (U+000B)
- Form Feed (FF) (U+000C)
- Carriage Return (CR) (U+000D)
- Next Line (NEL) (U+0085)
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 |
---|---|---|---|
Axe-core | Consistent | Yes | View Report |
QualWeb | Consistent | Yes | View Report |
SortSite | Consistent | Yes | View Report |
Changelog
This is the first version of this ACT rule.