aria-voyager

Canoe vessel that navigates your aria.

A framework agnostic / universal package that implements navigation patterns for various aria roles and features.

BYOM: Bring Your Own Markup

... and this library will make it interactive, according to applicable ARIA patterns. This library does not apply styling, it will operate on the accessibility tree.

Supported Features

See hokulea/aria-voyager for a full list of supported features.

Installation

pnpm add aria-voyager

Usage

Controls

Listbox

Bring your own markup in at first, here is an example markup for a list:

<ul role="listbox">
  <li role="option">Banana</li>
  <li role="option" aria-selected="true">Apple</li>
  <li role="option">Mango</li>
</ul>

To make it interactive, create a new Listbox instance pointing it at your element.

import { Listbox } from 'aria-voyager';

const listElement = document.querySelector('[role="listbox"]');
new Listbox(listElement);

That is already enough to start making your listbox interactive. It will read the options from the provided HTML.

Listbox accepts options as second parameter:

import type { EmitStrategy, UpdateStrategy } from 'aria-voyager';

interface ListboxOptions {
  updater?: UpdateStrategy;
  emitter?: EmitStrategy;
}

See updater and emitter.

Menu

Bring your own markup in at first, here is an example markup for a menu:

<div role="menu">
  <button role="menuitem">Version Info</button>
  <a role="menuitem" href="https://github.com/hokulea/aria-voyager" target="_blank">Github</a>
  <button role="menuitem" popovertarget="authormenu">Author</button>
  <div role="menu" id="authormenu" popover>
    <a role="menuitem" href="https://gos.si" target="_blank">Homepage</a>
    <a role="menuitem" href="https://github.com" target="_blank">Github</a>
  </div>
</div>

To make it interactive, create a new Menu instance pointing it at your element.

import { Menu } from 'aria-voyager';

const menuElement = document.querySelector('[role="menu"]');
new Menu(menuElement);

Menu accepts options as second parameter:

import type { EmitStrategy, UpdateStrategy } from 'aria-voyager';

interface MenuOptions {
  updater?: UpdateStrategy;
  emitter?: EmitStrategy;
}

See updater and emitter.

Strategies

aria-voyager supports the concept of input (updater) and output (emitter) through exchangeable strategies.

Updater

The job of an updater is to tell the controls, when new updates are available, such as selection has changed, new elements were added or existing ones removed from the DOM.

By default, aria-voyager uses the DOMOberserverUpdateStrategy which - as the name suggests - observes the DOM for changes. So the controls stay updated from your changes to the DOM.

That might be inefficient given different rendering strategies in the various frontend frameworks flush changes more frequent than what seems the right dosis for such a DOMObserver.

To optimize this, there is a blank ReactiveUpdateStrategy, which you can extend to write a framework integration. With that you can hook into the reactivity system of your framework and tell aria-voyager when updates are available.

Emitter

Controls are interactive elements, so you also want to know when things are happening to react on user interactions.

Emitters are the way to receive those events. aria-voyager ships with two strategies, that emit changes:

1. IndexEmitStrategy which tells you the indexes of the elements, based on the index of an elements amongst its children in the DOM.

2. ItemEmitStrategy which tells you which elements are changed.

Both are suited to write a framework integration to bridge between DOM and your application code.