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Description

Each image that is not marked as decorative, has an accessible name

Accessibility Requirements

This conformance rule relates to:

Test procedure

Applicability

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

Expectation

Each target element has an accessible name that is non-empty or is marked as decorative.

NOTE: An img element can be marked as decorative, by using either role="presentation", role="none" or an empty alt attribute alt="".

Assumptions

There are currently no assumptions.

Accessibility Support

There is a known combination of a popular browser and assistive technology that does not by default support title as an accessible name.

Background

Test cases

Passed

Passed example 1

HTML img element has accessible name

Code Snippet:
 <img alt="W3C logo" />
 
Example Output: Open in a new tab/ window

Passed example 2

Element with role of img and accessible name

Code Snippet:
 <div role="img" aria-label="W3C logo"></div>
 
Example Output: Open in a new tab/ window

Passed example 3

Accessible name but not always accessibility supported

Code Snippet:
 <img title="W3C logo" />
 
Example Output: Open in a new tab/ window

Passed example 4

HTML img element marked as decorative through empty alt attribute

Code Snippet:
 <img alt="" />
 
Example Output: Open in a new tab/ window

Passed example 5

HTML img element marked as decorative through role="presentation"

Code Snippet:
 <img role="presentation" />
 
Example Output: Open in a new tab/ window

Passed example 6

HTML img element marked as decorative through role="none"

Code Snippet:
 <img role="none" />
 
Example Output: Open in a new tab/ window

Failed

Failed example 1

HTML img element that is not marked as decorative and does not have accessible name

Code Snippet:
 <img />
 
Example Output: Open in a new tab/ window

Failed example 2

Element with role of img but no accessible name

Code Snippet:
 <div role="img"></div>
 
Example Output: Open in a new tab/ window

Failed example 3

Image element inside a div positioned off screen with no accessible name and is not marked as decorative

Code Snippet:
 <div style="margin-left:-9999px;"><img /></div>
 
Example Output: Open in a new tab/ window

Inapplicable

Inapplicable example 1

Element that does not have the semantic role of img

Code Snippet:
 <svg xmlns="http://www.w3.org/2000/svg" width="100" height="100">
  <circle cx="50" cy="50" r="40" stroke="green" stroke-width="4" fill="yellow" />
</svg>
 
Example Output: Open in a new tab/ window

Inapplicable example 2

Element with semantic role of img is not included in the accessibility tree

Code Snippet:
 <div role="img" aria-hidden="true"></div>
 
Example Output: Open in a new tab/ window

Inapplicable example 3

HTML img element is not included in the accessibility tree

Code Snippet:
 <img alt="W3C logo" aria-hidden="true" />
 
Example Output: Open in a new tab/ window

Glossary

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 and the SVG accessibility API mappings.

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.

Semantic Role

A semantic role is a semantic association that indicates an object’s type. This allows tools to present and support interaction with the object in a manner that is consistent with user expectations about other objects of that type.

Roles can be implicit through the element type or explicit through the role attribute.

The role attribute takes a list of tokens. The semantic role is the first valid role in this list. If none of the tokens are valid, the implicit role will be used instead.

Non-abstract roles defined in the following specifications are considered valid:

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.

Note: For HTML elements the implicit roles are documented in ARIA in HTML.

Accessible Name

The programatically 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 and SVG Accessibility API Mappings, Name and Description.

Decorative

Serving only an aesthetic purpose, providing no information, and having no functionality.

Non-empty text string

A string of characters (text) is considered “non-empty” if it contains 1 or more characters that are contained within any of the following unicode categories:

  • Ll: Letter, Lowercase
  • Lu: Letter, Uppercase
  • Lt: Letter, Titlecase
  • Lo: Letter, Other
  • Lm: Letter, Modifier
  • Nd: Number, Decimal Digit

For more details on unicode categories, check out www.fileformat.info/info/unicode/category/

Test Aspects

Test aspects are defined as part of the ACT Rules format 1.0.
  • DOM Tree

  • CSS Styling

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