Proposed Test Rule: Link is descriptive

Description

This rule checks that the accessible name of a link describes its purpose.

Applicability

This rule applies to any [semantic link][] for which all the following is true:

Expectation

Each test target has an accessible name which describes its purpose.

Assumptions

Accessibility Support

Background

Test Cases

Passed

Passed Example 1

This a element has an accessible name from its text that describes its purpose.

<a href="#desc">See the description of this product.</a>

<p id="desc">This product consists of several web pages.</p>

Passed Example 2

This a element has an accessible name from the alt attribute on its img element that describes its purpose.

<a href="#main"><img src="/test-assets/5effbb/main.png" alt="Go to the main content"/></a>

<main>
	<p id="main">This is the main content.</p>
</main>

Passed Example 3

This span element has an explicit role of link and an accessible name from its text that describes its purpose.

<span role="link" tabindex="0" onclick="document.location+='#desc'">See description of the product.</span>

<p id="desc">This product consists of several web pages.</p>

Passed Example 4

This a element has an accessible name from its aria-labelledby attribute that describes its purpose.

<p id="instructions">Go to the main content.</p>
<svg xmlns="http://www.w3.org/2000/svg" x="0" y="0">
	<a href="#main" aria-labelledby="instructions">
		<path
			style="fill:#1E201D;"
			d="M21.205,5.007c-0.429-0.444-1.143-0.444-1.587,0c-0.429,0.429-0.429,1.143,0,1.571l8.047,8.047H1.111
			C0.492,14.626,0,15.118,0,15.737c0,0.619,0.492,1.127,1.111,1.127h26.554l-8.047,8.032c-0.429,0.444-0.429,1.159,0,1.587
			c0.444,0.444,1.159,0.444,1.587,0l9.952-9.952c0.444-0.429,0.444-1.143,0-1.571L21.205,5.007z"
		/>
	</a>
</svg>

<main>
	<p id="main">This is the main content.</p>
</main>

Failed

Failed Example 1

This link has an accessible name which does not describe its purpose.

<a href="#desc">More</a>

<p id="desc">This product consists of several web pages.</p>

Failed Example 2

This link has an accessible name which does not describe its purpose.

<div role="link" tabindex="0" onclick="document.location+='#main'">More</div>

<main>
	<p id="main">This is the main content.</p>
</main>

Failed Example 3

This link has an accessible name which does not describe its purpose.

<svg xmlns="http://www.w3.org/2000/svg" x="0" y="0">
	<a href="#main">
		<text x="20" y="20">
			Go
		</text>
	</a>
</svg>

<main>
	<p id="main">This is the main content.</p>
</main>

Failed Example 4

This link has an accessible name which, alone, does not describe its purpose.

<p>See the description of <a href="#desc">this product</a>.</p>

<p id="desc">This product consists of several web pages.</p>

Failed Example 5

These links have accessible names which, alone, do not describe their purpose.

<ul>
	<li>
		Ulysses
		<ul>
			<li><a href="https://www.gutenberg.org/files/4300/4300-h/4300-h.htm"> HTML </a></li>
			<li>
				<a href="https://www.gutenberg.org/ebooks/4300.epub.images?session_id=04cd710372888de8d8d322215cdfe8ce5b0f8d73">
					EPUB
				</a>
			</li>
			<li><a href="https://www.gutenberg.org/files/4300/4300-0.txt"> Plain text </a></li>
		</ul>
	</li>
</ul>

Inapplicable

Inapplicable Example 1

There is no [semantic link][] in this document.

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

Inapplicable Example 2

This link is not included in the accessibility tree.

<a href="https://www.w3.org/WAI" style="display: none;"
	><img src="/test-assets/5effbb/cart.svg" alt="Checkout" />Checkout</a
>

Inapplicable Example 3

There is no [semantic link][] in this document (a element without an href attribute do not have a role of link).

<a>placeholder</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:

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:

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:

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.

A semantic link is any element which has the [semantic role][] of link or a [semantic role][] that inherits from the link role.

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.

WAI-ARIA specifications

The WAI ARIA Specifications group both the WAI ARIA W3C Recommendation and ARIA modules, namely:

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.

[sc249]: https://www.w3.org/TR/WCAG21/#link-purpose-link-only ‘Success Criterion 2.4.9 [semantic link]: #semantic-link ‘Definition of Semantic Link’ [semantic role]: #semantic-role ‘Definition of Semantic Role’ [usc249]: https://www.w3.org/WAI/WCAG21/Understanding/link-purpose-link-only.html ‘Understanding Success Criterion 2.4.9 [wai-aria specifications]: #wai-aria-specifications ‘Definition of WAI-ARIA specifications’

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This is an unpublished draft preview that might include content that is not yet approved. The published website is at w3.org/WAI/.