Visible label is part of accessible name

Applicability

This rule applies to any element for which all the following is true:

The element has a [semantic role][] that is a [widget][widget role] that [supports name from content][]; and
The element has [visible text content][]; and
The element has an aria-label or aria-labelledby attribute.

Expectation

For each target element, all [text nodes][] in the [visible text content][] [match characters][] and are contained within the [accessible name][] of this target element, except for characters in the [text nodes][] used to express [non-text content][]. Leading and trailing [whitespace][] and difference in case sensitivity should be ignored.

Assumptions

This rule assumes that all resources needed for rendering the page are properly loaded. Checking if resources are missing is out of the scope of rules. Missing resources may be rendered as text (for example, missing img are rendered as their alt attribute).

Accessibility Support

Implementation of [Presentational Roles Conflict Resolution][] varies from one browser or assistive technology to another. Depending on this, some elements can have one of the applicable [semantic roles][semantic role] and fail this rule with some technology but users of other technologies would not experience any accessibility issue.

Background

This rule applies to elements with a [widget role][] that [support name from content][supports name from content]. This includes the following: button, checkbox, gridcell, link, menuitem, menuitemcheckbox, menuitemradio, option, radio, searchbox, switch, tab, treeitem.

The understanding document of [2.5.3 Label in Name][understand253] use the term "symbolic text characters" to refer to a type of [non-text content][] that uses text characters as symbols, such as using "x" to mean "close". This rule considers them as "characters expressing non-text content". Unicode emojis are another example of characters expressing non-text content, although these are not "symbolic text characters".

Bibliography

[Understanding Success Criterion 2.5.3: Label in Name][understand253]
G208: Including the text of the visible label as part of the accessible name

Test Cases

Passed

Passed Example 1

This link has [visible][] text that matches the [accessible name][].

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

Passed Example 2

This link has [visible][] text that, ignoring trailing whitespace, matches the [accessible name][].

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

Passed Example 3

This link has [visible][] text that, ignoring case, matches the [accessible name][].

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

Passed Example 4

This button has [visible][] text that is contained within the [accessible name][].

<button aria-label="Next Page in the list">Next Page</button>

Passed Example 5

This button has [visible][] text that does not need to be contained within the [accessible name][], because the "x" text node is [non-text content][]. Note: this would need to meet SC 1.1.1 Non text content.

<button aria-label="anything">X</button>

Passed Example 6

This button element has the text "search" rendered as an magnifying glass icon by the font. Because the text is rendered as [non-text content][], the text does not need to be contained within the [accessible name][].

<link href="https://fonts.googleapis.com/icon?family=Material+Icons" rel="stylesheet" />
<style>
	button {
		font-family: 'Material Icons';
	}
</style>
<button aria-label="Find">search</button>

Failed

Failed Example 1

This link has [visible][] text that is different from the [accessible name][].

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

Failed Example 2

This button has [visible][] text that is only partially contained within the [accessible name][].

<button aria-label="the full">The full label</button>

Failed Example 3

This link has [visible][] text with mathematical symbols, that does not match the [accessible name][] because the mathematical symbols were written out in the accessible name. This is explicitly mentioned in WCAG.

<a href="/" aria-label="Proof of two multiplied by two is four">Proof of 2&times;2=4</a>

Failed Example 4

This link has [visible][] text does not match the [accessible name][] because there is a hyphen in the accessible name.

<a href="#" aria-label="non-standard">nonstandard</a>

Failed Example 5

This link has [visible][] text does not match the [accessible name][] because there are extra spaces in the accessible name.

<a aria-label="1 2 3. 4 5 6. 7 8 9 0" href="tel:1234567890">123.456.7890</a>

Inapplicable

Inapplicable Example 1

This nav is not a widget, so the [visible][] text does not need to match the [accessible name][].

<nav aria-label="main nav">W3C navigation</nav>

Inapplicable Example 2

This email text field does not need to have its [visible][] text match the [accessible name][]. The content of a textfield shows its value instead of its label; it does not [support name from content][supports name from content]. The label is usually adjacent to the textfield instead.

<div>E-mail</div>
<input type="email" aria-label="E-mail" value="Contact" />

Inapplicable Example 3

This div element does not have a widget role, so the [visible][] text does not need to match the [accessible name][].

<div role="tooltip" aria-label="OK">Next</div>

Inapplicable Example 4

This link has no [visible text content][].

<a href="https://w3.org" aria-label="W3C homepage">
	<img src="/test-assets/shared/w3c-logo.png" alt="w3c logo" />
</a>

AI Prompt

Create a PHP class in the namespace "App\Services\AccessibilityAnalyzer\ActRules"
that extends "App\Services\AccessibilityAnalyzer\ActRuleRunner" and is called "VisibleLabelInAccessibleName2ee8b8" that has a function with the signature "protected function findApplicableElements(Crawler $crawler): Crawler". The base class includes the function "protected function isElementIncludedInAccessibilityTree(\DOMNode $element): bool" for determining if an element is included in the accessibility tree.

Web accessibility rule:

# Visible label is part of accessible name

metadata:
    id: 2ee8b8
    name: 'Visible label is part of accessible name'
    rule_type: atomic
    description: "This rule checks that interactive elements labeled through content have their visible label as part of their accessible name.\n"
    accessibility_requirements: { 'wcag21:2.5.3': { forConformance: true, failed: 'not satisfied', passed: 'further testing needed', inapplicable: 'further testing needed' }, 'wcag-technique:G208': { forConformance: false, failed: 'not satisfied', passed: 'further testing needed', inapplicable: 'further testing needed' } }
    input_aspects: ['Accessibility Tree', 'DOM Tree', 'CSS Styling']
    acknowledgments: { authors: ['Anne Thyme Nørregaard', 'Bryn Anderson', 'Jey Nandakumar'], funding: [WAI-Tools] }

## Applicability

This rule applies to any element for which all the following is true:

- The element has a [semantic role][] that is a [widget][widget role] that [supports name from content][]; and
- The element has [visible text content][]; and
- The element has an `aria-label` or `aria-labelledby` attribute.

## Expectation

For each target element, all [text nodes][] in the [visible text content][] [match characters][] and are contained within the [accessible name][] of this target element, except for characters in the [text nodes][] used to express [non-text content][]. Leading and trailing [whitespace][] and difference in case sensitivity should be ignored.

## Assumptions

This rule assumes that all resources needed for rendering the page are properly loaded. Checking if resources are missing is out of the scope of rules. Missing resources may be rendered as text (for example, missing `img` are rendered as their `alt` attribute).

## Accessibility Support

Implementation of [Presentational Roles Conflict Resolution][] varies from one browser or assistive technology to another. Depending on this, some elements can have one of the applicable [semantic roles][semantic role] and fail this rule with some technology but users of other technologies would not experience any accessibility issue.

## Background

This rule applies to elements with a [widget role][] that [support name from content][supports name from content]. This includes the following: `button`, `checkbox`, `gridcell`, `link`, `menuitem`, `menuitemcheckbox`, `menuitemradio`, `option`, `radio`, `searchbox`, `switch`, `tab`, `treeitem`.

The understanding document of [2.5.3 Label in Name][understand253] use the term "symbolic text characters" to refer to a type of [non-text content][] that uses text characters as symbols, such as using "x" to mean "close". This rule considers them as "characters expressing non-text content". Unicode emojis are another example of characters expressing non-text content, although these are not "symbolic text characters".

### Bibliography

- [Understanding Success Criterion 2.5.3: Label in Name][understand253]
- [G208: Including the text of the visible label as part of the accessible name](https://www.w3.org/WAI/WCAG22/Techniques/general/G208)

## Test Cases

### Passed

#### Passed Example 1

This link has [visible][] text that matches the [accessible name][].

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

#### Passed Example 2

This link has [visible][] text that, ignoring trailing whitespace, matches the [accessible name][].

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

#### Passed Example 3

This link has [visible][] text that, ignoring case, matches the [accessible name][].

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

#### Passed Example 4

This button has [visible][] text that is contained within the [accessible name][].

```html
<button aria-label="Next Page in the list">Next Page</button>
```

#### Passed Example 5

This button has [visible][] text that does not need to be contained within the [accessible name][], because the "x" text node is [non-text content][]. Note: this would need to meet SC 1.1.1 Non text content.

```html
<button aria-label="anything">X</button>
```

#### Passed Example 6

This `button` element has the text "search" rendered as an magnifying glass icon by the font. Because the text is rendered as [non-text content][], the text does not need to be contained within the [accessible name][].

```html
<link href="https://fonts.googleapis.com/icon?family=Material+Icons" rel="stylesheet" />
<style>
	button {
		font-family: 'Material Icons';
	}
</style>
<button aria-label="Find">search</button>
```

### Failed

#### Failed Example 1

This link has [visible][] text that is different from the [accessible name][].

```html
<a href="https://act-rules.github.io/" aria-label="WCAG">ACT rules</a>
```

#### Failed Example 2

This button has [visible][] text that is only partially contained within the [accessible name][].

```html
<button aria-label="the full">The full label</button>
```

#### Failed Example 3

This link has [visible][] text with mathematical symbols, that does not match the [accessible name][] because the mathematical symbols were written out in the accessible name. This is [explicitly mentioned in WCAG](https://www.w3.org/WAI/WCAG22/Understanding/label-in-name#mathematical-expressions-and-formulae).

```html
<a href="/" aria-label="Proof of two multiplied by two is four">Proof of 2&times;2=4</a>
```

#### Failed Example 4

This link has [visible][] text does not match the [accessible name][] because there is a hyphen in the accessible name.

```html
<a href="#" aria-label="non-standard">nonstandard</a>
```

#### Failed Example 5

This link has [visible][] text does not match the [accessible name][] because there are extra spaces in the accessible name.

```html
<a aria-label="1 2 3. 4 5 6. 7 8 9 0" href="tel:1234567890">123.456.7890</a>
```

### Inapplicable

#### Inapplicable Example 1

This `nav` is not a widget, so the [visible][] text does not need to match the [accessible name][].

```html
<nav aria-label="main nav">W3C navigation</nav>
```

#### Inapplicable Example 2

This email text field does not need to have its [visible][] text match the [accessible name][]. The content of a textfield shows its value instead of its label; it does not [support name from content][supports name from content]. The label is usually adjacent to the textfield instead.

```html
<div>E-mail</div>
<input type="email" aria-label="E-mail" value="Contact" />
```

#### Inapplicable Example 3

This `div` element does not have a widget role, so the [visible][] text does not need to match the [accessible name][].

```html
<div role="tooltip" aria-label="OK">Next</div>
```

#### Inapplicable Example 4

This link has no [visible text content][].

```html
<a href="https://w3.org" aria-label="W3C homepage">
	<img src="/test-assets/shared/w3c-logo.png" alt="w3c logo" />
</a>
```