svg element with explicit role has accessible name

  • Rule Typeatomic
  • Rule ID: 7d6734
  • Last modified: -
  • 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 above on level A and above.
      • Outcome mapping:
        • Any failed outcomes: not satisfied.
        • All passed outcomes: further testing needed.
        • An inapplicable outcome: further testing needed.
  • Input Aspects

Description

This rule checks that each SVG image element that is explicitly included in the accessibility tree has an accessible name.

Applicability

The rule applies to any element in the SVG namespace with an explicit semantic role of either img, graphics-document, graphics-symbol, that is included in the accessibility tree.

Note: The SVG Accessibility API Mappings specifies that many elements in the SVG namespace are purely presentational and should not be included in the accessibility tree unless indicated otherwise through the use of text alternative content, an explicit WAI ARIA role, or a valid tabindex attribute.

Expectation

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

Assumptions

This rule assumes that the presence of one of the roles outlined in the applicability indicates the authors intent to include the element in the accessibility tree and thus convey information to the user about that element.

Accessibility Support

The HTML Accessibility API Mappings specify that the <svg> element has an implicit role of graphics-document. However browser support for the graphics-document role and the SVG Accessibility API Mappings is inconsistent.

This rule is limited to the explicit use of roles, as a clear indication that content should convey meaning, until the SVG Accessibility API Mappings is more stable and browser support is more consistent.

Browser and assistive technology support for SVG <title> and <desc> elements is currently inconsistent. Using WAI ARIA in combination with the img role for non-decorative <svg> elements significantly improves accessibility browser support.

Until browser support for the SVG Accessibility API Mappings is more consistent it is recommended to explicitly remove decorative elements from the accessibility tree.

Background

Test Cases

Passed

Passed Example 1

The svg element has an explicit role of img and an accessible name from the title element that is not empty.

<p>How many circles are there?</p>
<svg xmlns="http://www.w3.org/2000/svg" role="img" width="100" height="100">
	<title>1 circle</title>
	<circle cx="50" cy="50" r="40" fill="yellow"></circle>
</svg>

Passed Example 2

The circle element has an explicit role of graphics-symbol and an accessible name from the aria-label attribute that is not empty.

<p>How many circles are there?</p>
<svg xmlns="https://www.w3.org/2000/svg">
	<circle
		role="graphics-symbol"
		cx="50"
		cy="50"
		r="40"
		stroke="green"
		stroke-width="4"
		fill="yellow"
		aria-label="1 circle"
	></circle>
</svg>

Passed Example 3

The svg element has an explicit role of graphics-document and an accessible name from the title element that is not empty.

<p>How many circles are there?</p>
<svg xmlns="http://www.w3.org/2000/svg" role="graphics-document" width="100" height="100">
	<title>1 circle</title>
	<circle cx="50" cy="50" r="40" fill="yellow"></circle>
</svg>

Failed

Failed Example 1

The svg element has an explicit role of img but has no accessible name.

<p>How many circles are there?</p>
<svg xmlns="http://www.w3.org/2000/svg" role="img">
	<circle cx="50" cy="50" r="40" stroke="green" stroke-width="4" fill="yellow"></circle>
</svg>

Failed Example 2

The svg element has an explicit role of img but has only whitespace in the title element for the accessible name.

<p>How many circles are there?</p>
<svg xmlns="http://www.w3.org/2000/svg" role="img">
	<title></title>
	<circle cx="50" cy="50" r="40" fill="yellow"></circle>
</svg>

Failed Example 3

The svg element has an explicit role of img, is included in the accessibility tree, but it has no accessible name because the title element is empty.

<p>How many circles are there?</p>
<svg xmlns="http://www.w3.org/2000/svg" role="img">
	<title></title>
	<circle cx="50" cy="50" r="40" fill="yellow"></circle>
</svg>

Failed Example 4

The circle element has an explicit role of graphics-symbol but does not have an accessible name.

<p>How many circles are there?</p>
<svg xmlns="http://www.w3.org/2000/svg">
	<circle role="graphics-symbol" cx="50" cy="50" r="40" stroke="green" stroke-width="4" fill="yellow"></circle>
</svg>

Inapplicable

Inapplicable Example 1

Both the svg and circle elements do not have an explicit role.

<svg xmlns="http://www.w3.org/2000/svg">
	<circle cx="50" cy="50" r="40" fill="yellow"></circle>
</svg>

Inapplicable Example 2

The svg element has an explicit role of img but the aria-hidden attribute removes the element and its descendants from the accessibility tree.

<svg xmlns="http://www.w3.org/2000/svg" role="img" aria-hidden="true">
	<circle cx="50" cy="50" r="40" fill="yellow"></circle>
</svg>

Inapplicable Example 3

The circle element has an explicit role that is neither img, graphics-document or graphics-symbol.

<svg xmlns="http://www.w3.org/2000/svg">
	<circle role="graphics-object" cx="50" cy="50" r="40" fill="yellow"></circle>
</svg>

Glossary

Accessible Name

key: accessible-name

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

  • 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

Note: The examples presented here are non-normative and not testable. They serve to illustrate some common pitfalls about the definition and 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.

Included in the accessibility tree

key: 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

Note: The examples presented here are non-normative and not testable. They serve to illustrate some common pitfalls about the definition and 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

key: outcome

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: Implementers 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.


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Acknowledgements

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