makeup-active-descendant

makeup-active-descendant

Implements ARIA active descendant keyboard navigation.

A vanilla JavaScript port of jquery-active-descendant.

Experimental

This module is still in an experimental state, until it reaches v1.0.0 you must consider all minor releases as breaking changes. Patch releases may introduce new features, but will be backwards compatible.

Install

// via npm
npm install makeup-active-descendant

// via yarn
yarn add makeup-active-descendant

Example

// require the module
const ActiveDescendant = require('makeup-active-descendant');

// get the widget root element reference
const widgetEl = document.querySelector('.widget');

// get the focus element reference
const focusEl = widgetEl.querySelector('input');

// get the owned element reference
const ownedEl = widgetEl.querySelector('ul');

// create an activeDescendant widget instance on the element
const activeDescendant = ActiveDescendant.createLinear(widgetEl, focusEl, ownedEl, 'li');

// listen for events (optional)
widgetEl.addEventListener('activeDescendantChange', function(e) {
    console.log(e.detail);
});

Markup before:

<div class="widget">
    <input type="text">
    <ul>
        <li>Item 1</li>
        <li>Item 2</li>
        <li>Item 3</li>
    </ul>
</div>

Markup after instantiation:

<div class="widget" id="widget-0">
    <input type="text" aria-owns="widget-0-list-0">
    <ul id="widget-0-list-0">
        <li id="widget-0-item-0" data-makeup-index="0">Item 1</li>
        <li id="widget-0-item-1" data-makeup-index="1">Item 2</li>
        <li id="widget-0-item-2" data-makeup-index="2">Item 3</li>
    </ul>
</div>

Markup after pressing down arrow key on focusable element:

<div class="widget" id="widget-0">
    <input type="text" aria-activedescendant="widget-0-item-0" aria-owns="widget-0-list-0">
    <ul id="widget-0-list-0">
        <li class="active-descendant" id="widget-0-item-0" data-makeup-index="0">Item 1</li>
        <li id="widget-0-item-1" data-makeup-index="1">Item 2</li>
        <li id="widget-0-item-2" data-makeup-index="2">Item 3</li>
    </ul>
</div>

Use CSS to style the active descendant however you wish:

.widget .active-descendant {
    font-weight: bold;
}

Options

• activeDescendantClassName: the HTML class name that will be applied to the ARIA active descendant element (default: 'active-descendant')
• autoInit: specify an integer or -1 for initial index (default: 0) (see makeup-navigation-emitter)
• autoReset: specify an integer or -1 for index position when focus exits widget (default: null) (see makeup-navigation-emitter)

Custom Events

• activeDescendantChange
  • detail
    • fromIndex
    • toIndex

Properties

• index: the index position of the current active descendant

Methods

• destroy: destroys all event listeners

Dependencies

• makeup-navigation-emitter
• makeup-next-id

Polyfills

• custom-event-polyfill
• nodelist-foreach-polyfill

Development

• npm start
• npm test
• npm run lint
• npm run fix
• npm run build
• npm run clean

Test Reports

Each test run will generate the following reports:

• /reports/coverage contains Istanbul code coverage report
• /reports/html contains HTML test report

CI Build

https://travis-ci.org/makeup-js/makeup-active-descendant

Code Coverage

https://coveralls.io/github/makeup-js/makeup-active-descendant