Proposed Test Rule: role attribute has valid value
Applicability
This rule applies to any role
attribute for which all the following are true:
- the attribute has a value that is neither empty (“”) nor only ASCII whitespace; and
- the attribute is specified on an HTML or SVG element which is not programmatically hidden.
Expectation
Each test target has at least one token which is a valid value corresponding to a non-abstract role from WAI-ARIA Specifications.
Assumptions
- This rule assumes that the
role
attribute is used to provide an ARIA semantic role to the elements. If it is used for other purposes, this rule shouldn’t be used. - This rule assumes that elements with a
role
attribute have their intended structure and relationship conveyed through some sort of presentation. If it is not the case, it is possible to fail this rule while still satisfying Success Criterion 1.3.1 Info and Relationship. - This rule assumes that the intended role of the element is not its implicit role. If no token is valid, User Agents will default to the implicit role for the element; if that role is the intended one, it is possible to fail this rule but still satisfy Success Criterion 1.3.1 Info and Relationship.
Accessibility Support
Older browsers do not support more than one token in the value for a role attribute. If multiple values are used in the role attribute, the attribute is ignored in these browsers.
Background
The role
attribute is a set of space separated tokens. Having a whitespace separated list of more than one token in the value of the role attribute is used for what is known as fallback roles. If the first token is not accessibility supported (or valid), the next one will be used for determining the semantic role of the element, and so forth. Having the rule target attributes containing at least one non-ASCII whitespace character ensures that there is at least one token in the set.
Bibliography
- List of WAI-ARIA Roles
- List of Graphics ARIA Roles
- List of DPUB ARIA Roles
- Specification of the
role
attribute - WAI-ARIA 1.1 Categorization of Roles
- WAI-ARIA Roles
Accessibility Requirements Mapping
1.3.1 Info and Relationships (Level A)
- Learn more about 1.3.1 Info and Relationships
- Required for conformance to WCAG 2.0 and later on level A 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
ARIA4: Using a WAI-ARIA role to expose the role of a user interface component
- Learn more about technique ARIA4
- 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
G108: Using markup features to expose the name and role, allow user-settable properties to be directly set, and provide notification of changes
- Learn more about technique G108
- 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
This role
attribute contains one token, and this token is a valid WAI-ARIA role.
<label>Search: <input type="text" role="searchbox" placeholder="Enter 3 or more characters"/></label>
Passed Example 2
This role
attribute contains two tokens, and these tokens are both valid WAI-ARIA roles.
<style>
.ref {
color: #0000ee;
text-decoration: underline;
cursor: pointer;
}
</style>
See [<span class="ref" onclick="location.href='https://act-rules.github.io/'" role="doc-biblioref link">ACT rules</span
>].
Passed Example 3
This role
attribute contains two tokens, and one of these tokens (searchbox
) is a valid WAI-ARIA role.
<label>Search: <input type="text" role="searchfield searchbox" placeholder="Enter 3 or more characters"/></label>
Failed
Failed Example 1
This role
attribute contains one token, but this token is not a valid role in any of the WAI-ARIA specifications.
<style>
.link {
color: #0000ee;
text-decoration: underline;
cursor: pointer;
}
</style>
I love <span class="link" onclick="location.href='https://act-rules.github.io/'" role="lnik">ACT rules</span>.
Failed Example 2
This role
attribute contains two tokens, but none of these tokens is a valid role in any of the WAI-ARIA specifications.
<style>
.ref {
color: #0000ee;
text-decoration: underline;
cursor: pointer;
}
</style>
See [<span class="ref" onclick="location.href='https://act-rules.github.io/'" role="bibliographic-reference lnik"
>ACT rules</span
>].
Inapplicable
Inapplicable Example 1
There is no role
attribute.
<img src="/test-assets/shared/w3c-logo.png" alt="W3C logo" />
Inapplicable Example 2
This role
attribute has no value.
<div role>Some Content</div>
Inapplicable Example 3
This role
attribute is empty (“”).
<div role="">Some Content</div>
Inapplicable Example 4
This role
attribute is only ASCII whitespace.
<input type="text" role=" " />
Inapplicable Example 5
This role
attribute is specified on an element which is programmatically hidden.
<div aria-hidden="true" role="banner">Some Content</div>
Glossary
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.
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.
Namespaced Element
An element with a specific namespaceURI value from HTML namespaces. For example an “SVG element” is any element with the “SVG namespace”, which is http://www.w3.org/2000/svg
.
Namespaced elements are not limited to elements described in a specification. They also include custom elements. Elements such as a
and title
have a different namespace depending on where they are used. For example a title
in an HTML page usually has the HTML namespace. When used in an svg
element, a title
element has the SVG namespace instead.
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.
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
hidden
attribute; or - has a computed CSS property
display
ofnone
; or - has an
aria-hidden
attribute set totrue
Note: Contrarily to the other conditions, the visibility
CSS property may be reverted by descendants.
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
.
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 |
---|---|---|---|
QualWeb | Consistent | Yes | View Report |
SortSite | Consistent | Yes | View Report |
Changelog
This is the first version of this ACT rule.