Link has non-empty accessible name

  • Rule Type:atomic
  • Rule Id: c487ae
  • Last modified: Jul 10, 2020
  • 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 above on level A and above.
      • 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.
    • 2.4.4 Link Purpose (In Context) (Level: A)
      • Learn More about 2.4.4 (Link Purpose (In Context))
      • Required for conformance to WCAG 2.0 and above on level A and above.
      • 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.
    • 2.4.9 Link Purpose (Link Only) (Level: AAA)
      • Learn More about 2.4.9 (Link Purpose (Link Only))
      • Required for conformance to WCAG 2.0 and above on level AAA and above.
      • 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.
    • G91: Providing link text that describes the purpose of a link

Description

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

Applicability

The rule applies to any HTML element with the semantic role of link that is included in the accessibility tree.

Expectation

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

Assumptions

The rule assumes that all links are user interface components as defined by WCAG 2. When the link role is used on elements that do not behave as links, failing this rule might not mean that the success criteria are failed.

Accessibility Support

  • There are assistive technologies that do not support using the title attribute for an accessible name, or in which this feature can be disabled.
  • For area elements that have an href attribute, but are not nested inside a map element, there are differences between browsers and assistive technology on if the area is included in the accessibility tree.
  • 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 link and fail this rule with some technology but users of other technologies would not experience any accessibility issue.

Background

Test Cases

Passed

Passed Example 1

Open in a new tab

This a element has an accessible name from its content.

<a href="http://www.w3.org/WAI"> Web Accessibility Initiative (WAI) </a>

Passed Example 2

Open in a new tab

This div element has an explicit semantic role of link and an accessible name from its content.

<div role="link" onclick="window.location.href='https://www.w3.org/WAI/'">Web Accessibility Initiative (WAI)</div>

Passed Example 3

Open in a new tab

This button element has an explicit semantic role of link and an accessible name from its content.

<button role="link" onclick="window.location.href='https://www.w3.org/WAI/'">Click me for WAI!</button>

Passed Example 4

Open in a new tab

This a element has an accessible name via aria-label

<a href="http://www.w3.org/WAI"
	><img src="/test-assets/shared/w3c-logo.png" aria-label="Web Accessibility Initiative"
/></a>

Passed Example 5

Open in a new tab

This a element has an accessible name via title.

<a href="http://www.w3.org/WAI" title="Web Accessibility Initiative"
	><img src="/test-assets/shared/w3c-logo.png" alt=""
/></a>

Passed Example 6

Open in a new tab

This a element has an accessible name from its content via the title on the img element.

<a href="http://www.w3.org/WAI"><img src="/test-assets/shared/w3c-logo.png" title="Web Accessibility Initiative"/></a>

Passed Example 7

Open in a new tab

This a element has an accessible name from its content.

<a href="http://www.w3.org/WAI"
	><img src="/test-assets/shared/w3c-logo.png" alt="" />Web Accessibility Initiative (WAI)</a
>

Passed Example 8

Open in a new tab

This a element has an accessible name from its content via aria-labelledby on the img element.

<a href="http://www.w3.org/WAI"><img src="/test-assets/shared/w3c-logo.png" aria-labelledby="id1"/></a>
<div id="id1">Web Accessibility Initiative (WAI)</div>

Passed Example 9

Open in a new tab

This a element placed off screen has an accessible name from its content.

<html>
	<style>
		.offScreenLink {
			position: absolute;
			left: -9999px;
			top: -9999px;
		}
	</style>
	<body>
		<a class="offScreenLink" href="http://www.w3.org/WAI">Web Accessibility Initiative (WAI)</a>
	</body>
</html>

Passed Example 10

Open in a new tab

This area element has a semantic role of link and an accessible name via alt.

<img src="/test-assets/c487ae/planets.jpg" width="145" height="126" alt="Planets" usemap="#planetmap" />

<map name="planetmap">
	<area shape="rect" coords="0,0,30,100" href="sun.htm" alt="Sun" />
</map>

Failed

Failed Example 1

Open in a new tab

This a element has an empty accessible name.

<a href="http://www.w3.org/WAI"><img src="/test-assets/shared/w3c-logo.png" role="none"/></a>

Failed Example 2

Open in a new tab

This a element with a decorative image has an empty accessible name.

<a href="http://www.w3.org/WAI"><img src="/test-assets/shared/w3c-logo.png" alt=""/></a>

Failed Example 3

Open in a new tab

This a element with an img with an empty title has an empty accessible name.

<a href="http://www.w3.org/WAI"><img src="/test-assets/shared/w3c-logo.png" title=""/></a>

Failed Example 4

Open in a new tab

This a element with an img with an aria-labelledby has an empty accessible name.

<a href="http://www.w3.org/WAI"><img src="/test-assets/shared/w3c-logo.png" aria-labelledby="id1"/></a>
<div id="id1"></div>

Failed Example 5

Open in a new tab

This a element with an img with an aria-labelledby referencing a non-existing id has an empty accessible name.

<a href="http://www.w3.org/WAI"><img src="/test-assets/shared/w3c-logo.png" aria-labelledby="id1"/></a>

Failed Example 6

Open in a new tab

This a element placed off screen has an empty accessible name.

<a href="http://www.w3.org/WAI" style="left: -9999px; position: absolute;">
	<img src="/test-assets/shared/w3c-logo.png" />
</a>

Failed Example 7

Open in a new tab

This a element has an empty accessible name.

<a href="http://www.w3.org/WAI"></a>

Failed Example 8

Open in a new tab

This area element has a semantic role of link and an empty accessible name.

<img src="/test-assets/c487ae/planets.jpg" width="145" height="126" alt="Planets" usemap="#planetmap" />

<map name="planetmap">
	<area shape="rect" coords="0,0,82,126" href="sun.htm" />
</map>

Failed Example 9

Open in a new tab

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

<a href="http://www.w3.org/WAI" role="none"> </a>

Inapplicable

Inapplicable Example 1

Open in a new tab

This a element does not have a semantic role of link because it has been changed to button.

<a href="http://www.w3.org/WAI" role="button">
	Web Accessibility Initiative (WAI)
</a>

Inapplicable Example 2

Open in a new tab

This a element is not included in the accessibility tree due to display: none.

<a href="http://www.w3.org/WAI" style="display: none;"><img src="/test-assets/shared/w3c-logo.png"/></a>

Inapplicable Example 3

Open in a new tab

This a element is not included in the accessibility tree due to visibility: hidden.

<a href="http://www.w3.org/WAI" style="visibility: hidden;">Some text</a>

Inapplicable Example 4

Open in a new tab

This a element is not included in the accessibility tree due to aria-hidden="true".

<a aria-hidden="true" href="http://www.w3.org/WAI">
	Web Accessibility Initiative (WAI)
</a>

Inapplicable Example 5

Open in a new tab

This area element does not have the role of link because it does not have an href attribute.

<area shape="rect" coords="0,0,82,126" />

Inapplicable Example 6

Open in a new tab

This a element does not have the role of link because it does not have an href attribute.

<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).

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.

Accessibility Support for Accessible Name

  • Because the accessible name and description computation is not clear about which whitespace are considered, browsers behave differently when trimming and flattening the accessible name. For example, some browsers completely trim non-breaking spaces while some keep them in the accessible name.
  • There exists a popular browser which does not perform the same trimming and flattening depending whether the accessible name comes from content, an aria-label attribute, or an alt attribute.
  • There exists a popular browser which assign no accessible name (null) when none is provided, instead of assigned an empty accessible name ("").

Examples for Accessible Name

Note: The examples presented here are non-normative and not testable. They serve to illustrate some common pitfalls about the definition and to help implementers of ACT rules understand it.

The input elements have an accessible name of, respectively, "Billing Name" and "Billing Address". These accessible names are given by the aria-labelledby attributes and associated elements.

<div id="myBillingId">Billing</div>

<div>
	<div id="myNameId">Name</div>
	<input type="text" aria-labelledby="myBillingId myNameId" />
</div>
<div>
	<div id="myAddressId">Address</div>
	<input type="text" aria-labelledby="myBillingId myAddressId" />
</div>

This button element has an accessible name of "Share ACT rules" given by its aria-label attribute.

<button aria-label="Share ACT rules">Share</button>

This img element has an accessible name of "ACT rules" given by its alt attribute.

<img src="#" alt="ACT rules" />

The button element has an accessible name of "Share ACT rules" given by the enclosing label element (implicit label)

<label>Share ACT rules<button>Share</button></label>

The button element has an accessible name of "Share ACT rules" given by the associated label element (explicit label)

<label for="act-rules">Share ACT rules</label><button id="act-rules"></button>

This a element has an accessible name of "ACT rules" given from its content. Note that not all semantic roles allow name from content.

<a href="https://act-rules.github.io/">ACT rules</a>

This span element has an empty accessible name ("") because span does not allow name from content.

<span>ACT rules</span>

This span element has an empty accessible name ("") because span is not a labelable element.

<label>ACT rules<span></span></label>

Note: When the same element can have an accessible name from several sources, the order of precedence is: aria-labelledby, aria-label, own attributes, label element, name from content. The examples here are listed in the same order.

Note: For more examples of accessible name computation, including many tricky cases, check the Accessible Name Testable Statements.

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.

Accessibility Support for Explicit Semantic Role

Some browsers and assistive technologies treat the tokens of the role attribute as case-sensitive. Unless lowercase letters are used for the value of the role attribute, not all user agents will be able to interpret the tokens correctly. ARIA in HTML (working draft) also specifies that authors must use lowercase letters for the role and aria-* attributes.

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).

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 with using sequential keyboard navigation regardless of the assistive technologies used, even though the element would not be included in the accessibility tree.

Examples for Included in the accessibility tree

Note: The examples presented here are non-normative and not testable. They serve to illustrate some common pitfalls about the definition and to help implementers of ACT rules understand it.

This span element is included in the accessibility tree (by default, elements are included in the accessibility tree).

<span>ACT rules</span>

This span element is not included in the accessibility tree because it is hidden to everybody by the CSS property.

<span style="display:none">ACT rules</span>

This span element is not included in the accessibility tree because it is explicitly removed by the aria-hidden attribute.

<span aria-hidden="true">ACT rules</span>

This span element is positioned off screen, hence is not visible, but is nonetheless included in the accessibility tree.

<span style="position: absolute; top:-9999em">ACT rules</span>

Although the span element with an id of "label" is not itself included in the accessibility tree, it still provides an accessible name to the other span, via the aria-labelledby attribute. Thus, it is still indirectly exposed to users of assistive technologies. Removing an element from the accessibility tree is not enough to remove all accessibility concerns from it since it can still be indirectly exposed.

<span id="label" style="display:none">ACT rules</span>
<span aria-labelledby="label">Accessibility Conformance Testing rules</span>

Although this input element is not included in the accessibility tree, it is still focusable, hence users of assistive technologies can still interact with it by sequential keyboard navigation. This may result in confusing situations for such users (and is in direct violation of the fourth rule of ARIA (working draft)).

<input type="text" aria-hidden="true" name="fname" />

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:

  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.

Accessibility Support for Definition of Semantic Role for Semantic Role

  • There exist popular web browsers and assistive technologies which do not correctly implement Presentational Roles Conflict Resolution. These technologies will not include in the accessibility tree elements that should be, according to Specifications. Thus, some elements that should have their semantic role fixed by case Conflict above are instead falling into case Explicit and are hidden for users of assistive technologies.
  • A similar conflict exists for focusable elements with a aria-hidden="true" attribute. The WAI ARIA specification does not explain how to solve it. Some browsers give precedence to the element being focusable (and expose it in the accessibility tree) while some give precedence to the aria-hidden attribute (and hide the element).

Useful Links


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. This section will not be included in the rule when it is published on the W3C website.

ToolConsitencyCompleteReport
AlfaconsistentYesView Report
QualWebconsistentYesView Report
SortSiteconsistentYesView Report
axe-corepartially-consistentYesView Report

Acknowledgments

image

  • Image used in passed example 10 and failed example 9 is courtesy of NASA/JPL-Caltech.
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