Proposed Form field label is descriptive
Description
This rule checks that labels describe the purpose of form field elements.
Applicability
This rule applies to any programmatic label of an element which has one of the following semantic roles:
checkbox
combobox
listbox
menuitemcheckbox
menuitemradio
radio
searchbox
slider
spinbutton
switch
textbox
and where both the element and the programmatic label are visible.
Note: The list of applicable semantic roles is derived by taking all the roles from WAI-ARIA Specifications that:
- inherit from the abstract
input
orselect
role; and - do not have a required context role that itself inherits from one of those roles.
Note: The option
role is not part of the list of applicable roles, because it has a required context role that inherits from the select
role. Furthermore, option
does not meet the definition of a User interface component. This means that WCAG 2.1 does not require it to have an accessible name.
Note: Labels in WCAG are not restricted to the label
element of HTML and can be any element. This rule is only concerned about actual label
elements, and elements that are programmatically marked as labels via the aria-labelledby
attribute.
Expectation
Each test target, together with its visual context, describes the purpose of the associated element.
Note: It is possible for an element to have an accessible name but still have a non-descriptive label
element (and even a non-descriptive label). In that case, it would pass Success Criterion 4.1.2: Name, Role and Value but still fail this rule and Success Criterion 2.4.6: Headings and Labels.
Note: Having a label which is not included in the accessible name is a violation of Success Criterion 2.5.3: Label in Name but not of this rule nor of Success Criterion 2.4.6: Headings and Labels.
Assumptions
- This rule assumes that labels are intended for sighted users, and that hiding a visible label from assistive technologies, is a failure of Success Criterion 4.1.2: Name, Role and Value, but not of Success Criterion 2.4.6: Headings and Labels.
- This rule assumes that the programmatic labels of an element are also part of its visual context.
- This rule assumes that the language of each test target can be correctly determined (either programmatically or by analyzing the content), and sufficiently understood.
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
Bibliography
- Accessible Rich Internet Applications (WAI-ARIA) 1.1
- Understanding Success Criterion 2.4.6: Headings and Labels
- Understanding Success Criterion 4.1.2: Name, Role and Value
- G131: Providing descriptive labels
- H44: Using label elements to associate text labels with form controls
- ARIA16: Using aria-labelledby to provide a name for user interface controls
Accessibility Requirements Mapping
2.4.6 Headings and Labels (Level AA)
- Learn more about 2.4.6 Headings and Labels
- Required for conformance to WCAG 2.0 and later on level AA 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
G131: Providing descriptive labels
- Learn more about technique G131
- 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 label
element is a programmatic label of the input
element and describes it.
<html lang="en">
<label>First name:<input id="fname" type="text" name="fname"/></label>
</html>
Passed Example 2
The label
element is a programmatic label of the input
element and describes it.
<html lang="en">
<label for="fname">First name:</label>
<input id="fname" type="text" name="fname" />
</html>
Passed Example 3
The p
element is a programmatic label of the input
element and describes it.
<html lang="en">
<p id="label_fname">First name:</p>
<input aria-labelledby="label_fname" type="text" name="fname" />
</html>
Passed Example 4
The p
element is a programmatic label of the input
element and describes it. The programmatic label does not need to be included in the accessibility tree for this rule to apply.
<html lang="en">
<p id="label_fname" aria-hidden="true">First name:</p>
<input aria-labelledby="label_fname" type="text" name="fname" />
</html>
Passed Example 5
The label
elements are programmatic labels of their respective input
elements. The label
elements, are not descriptive enough (because they are repeated over several fields). However, the headings provide a visual context that differentiates the purpose of the otherwise identically named form fields. Within their visual context, the label
elements are descriptive of their respective input
elements.
<html lang="en">
<h2>Shipping</h2>
<label>Name<input id="shipping-name" type="text" name="name"/></label>
<label>Street<input id="shipping-street" type="text" name="street"/></label>
<h2>Billing</h2>
<label>Name<input id="billing-name" type="text" name="name"/></label>
<label>Street<input id="billing-street" type="text" name="street"/></label>
</html>
Passed Example 6
Both the div
and the span
elements are programmatic labels of the input
element. Each of them, within the visual context formed by the other one, is descriptive.
<html lang="en">
<div id="shipping">Shipping</div>
<span id="name">Name</span>
<input id="shipping-name" type="text" name="name" aria-labelledby="shipping name" />
</html>
Failed
Failed Example 1
The label
element is a programmatic label of the input
element but does not describe it.
<html lang="en">
<label>Menu<input id="fname" type="text" name="fname"/></label>
</html>
Failed Example 2
The label
element is a programmatic label of the input
element but does not describe it.
<html lang="en">
<label for="fname">Menu</label>
<input id="fname" type="text" name="fname" />
</html>
Failed Example 3
The span
element is a programmatic label of the input
element but does not describe it.
<html lang="en">
<p id="label_fname">Menu</p>
<input aria-labelledby="label_fname" type="text" name="fname" />
</html>
Failed Example 4
These label
elements are programmatic labels of their respective input
elements. They are not descriptive enough because they are reused on multiple fields. The headings are not visible. Therefore, they do not provide visual context.
<html lang="en">
<fieldset>
<h2 style="position: absolute; top: -9999px; left: -9999px;">Shipping address</h2>
<label>Name: <input type="text" name="shipping-name" /></label>
<label>Street: <input type="text" name="shipping-street" /></label>
</fieldset>
<fieldset>
<h2 style="position: absolute; top: -9999px; left: -9999px;">Billing address</h2>
<label>Name: <input type="text" name="billing-name" /></label>
<label>Street: <input type="text" name="billing-street" /></label>
</fieldset>
</html>
Failed Example 5
These button
and span
elements are both programmatic labels of the input
element, but only the button
is visible. It has no visual context, and is not descriptive.
<html lang="en">
<span id="search" style="display: none">Search</span>
<input type="text" name="search" aria-labelledby="submit search" />
<button id="submit">Go</button>
</html>
Inapplicable
Inapplicable Example 1
The label
element is not a programmatic label of any element.
<html lang="en">
<label for="fname">First name:</label>
<p id="fname"></p>
</html>
Inapplicable Example 2
The label
element is not visible.
<html lang="en">
<label for="fname" style="position: absolute; left: -9999px;">First name:</label>
<label aria-hidden="true">First name:</label>
<input id="fname" type="text" name="fname" />
</html>
Inapplicable Example 3
The label
is a visible programmatic label of the input
element. However, the input
is not visible, hence this rule does not apply.
<html lang="en">
<label>First name: <input style="position: absolute; top: -9999px; left: -9999px;" disabled role="none" /></label>
</html>
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
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.
Programmatic Label
Element L is a programmatic label of target element T if either:
- T is a labeled control of L; or
- L is referenced by ID in the
aria-labelledby
attribute of T.
For more details, see examples of programmatic label.
Note: a given element may have more than one programmatic label.
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
.
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.
Visual Context
The visual context of a node is everything that is visually or logically located near it when the document containing it is rendered. Only visible information may be part of the visual context.
The logical distance is the distance in the structure of the document: either the tree distance within the DOM tree, or the semantic relation. For example, headings are logically near the content that follows (until the next heading of the same or higher level) even though they might be far away visually or in the DOM tree.
The visual context may include, but is not limited to, headings, text in the same sentence or paragraph.
Note: As a rule of thumb, visual context should be close enough to be displayed on the device at the same time as the element it relates to. Because device sizes vary wildly and content can further be zoomed and moved around, this is however not a strong requirement.
Note: Visual context that is located before (in reading order) the element it relates to is often more useful than visual context located after. Indeed, it is easier for users to use context that they have already read than context that is yet to be read.
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.
Implementations
There are currently no known implementations for this rule. If you would like to contribute an implementation, please read the ACT Implementations page for details.
Changelog
This is the first version of this ACT rule.