accessibility-checker-engine
Version:
An automated accessibility checking engine for use by other tools
104 lines (88 loc) • 5.1 kB
HTML
<html lang="en-US">
<head>
<title>aria_activedescendant_valid - Accessibility Checker Help</title>
<script>
RULE_MESSAGES = {"en-US":{"Pass_0":"Rule Passed","Fail_1":"The 'aria-activedescendant' property is empty","Fail_2":"The 'aria-activedescendant' property references a hidden node","Fail_3":"Element is not a combobox, and the referenced active-descendant element is not a valid descendant","Fail_4":"Element is a combobox, and the referenced active-descendant element is not controlled by this component","group":"The 'aria-activedescendant' property must reference the 'id' of a non-empty, non-hidden active child element"}};
RULE_ID = "aria_activedescendant_valid"
</script>
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<link rel="icon" href="https://ibm.com/able/favicon-32x32.png" type="image/png">
<link rel="icon" href="https://ibm.com/able/favicon.svg" type="image/svg+xml">
<link rel="stylesheet" href="../common/help.css" />
<script type="module">
import "https://1.www.s81c.com/common/carbon/web-components/version/v1.35.0/code-snippet.min.js";
import "https://1.www.s81c.com/common/carbon/web-components/version/v1.35.0/list.min.js";
</script>
<script src="https://cdn.jsdelivr.net/npm/marked/marked.min.js"></script>
<script src="../common/help.js"></script>
</head>
<body>
<div class="bx--grid toolHelp">
<div class="bx--row">
<div class="bx--col-sm-4 bx--col-md-8 bx--col-lg-16 toolHead">
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<h3 id="ruleMessage"></h3>
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<div id="locLevel"></div>
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<p id="groupLabel"></p>
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<div class="bx--row">
<div class="bx--col-sm-4 bx--col-md-5 bx--col-lg-8 toolMain">
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<mark-down><script type="text/plain">
### Why is this important?
In a composite component where the child elements are not normally able to take keyboard focus, the `aria-activedescendant` attribute can be used to identify the child element that currently has focus.
This enables proper keyboard control of the component and allows assistive technologies to gather information about the component and its state.
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<div id="locSnippet"></div>
### What to do
* Verify that the `aria-activedescendant` attribute value is the `id` of the currently active child element;
* **And**, verify that the child element is not hidden;
* **And**, verify that the child element is either a descendant of this element, or is owned by this element (indicated by using the aria-owns attribute on this element).
The following example* shows a radio group using `aria-activedescendant` to indicate the active radio button, which is coded as a DOM descendant:
```
<h3 id="group_label_1">Pizza Crust</h3>
<ul id="rg1" class="radiogroup" role="radiogroup" aria-labelledby="group_label_1" aria-activedescendant="rb11" tabindex="0">
<li id="rb11" role="radio" aria-checked="false">Regular crust</li>
<li id="rb12" role="radio" aria-checked="false">Deep dish</li>
<li id="rb13" role="radio" aria-checked="false">Thin crust</li>
</ul>
```
* Example code includes material copied from or derived from ARIA practices - Radio Group Example Using aria-activedescendant. Copyright © 2018-2019 W3C® (MIT, ERCIM, Keio, Beihang).
</script></mark-down>
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<div id="ruleInfo"></div>
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<div class="bx--col-sm-4 bx--col-md-3 bx--col-lg-4 toolSide">
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<mark-down><script type="text/plain">
### About this requirement
* [IBM 4.1.2 Name, Role, Value](https://www.ibm.com/able/requirements/requirements/#4_1_2)
* [ARIA practices - Developing a Keyboard Interface](https://www.w3.org/WAI/ARIA/apg/practices/keyboard-interface/)
### Who does this affect?
* People using a screen reader, including blind, low vision, and neurodivergent people
</script></mark-down>
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