An element that helps with announcing text through screen readers.
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README.md

Published on NPM Build status Published on webcomponents.org

<iron-a11y-announcer>

iron-a11y-announcer is a singleton element that is intended to add a11y to features that require on-demand announcement from screen readers. In order to make use of the announcer, it is best to request its availability in the announcing element. Note: announcements are only audible if you have a screen reader enabled.

See: Documentation, Demo

Usage

Installation

npm install --save @polymer/iron-a11y-announcer

In an html file

<html>
  <head>
    <script type="module">
      import {IronA11yAnnouncer} from '@polymer/iron-a11y-announcer/iron-a11y-announcer.js';
      // Initialize the announcer.
      IronA11yAnnouncer.requestAvailability();

      // Note: announcements are only audible if you have a screen reader enabled.
      IronA11yAnnouncer.instance.fire('iron-announce',
          {text: 'Hello there!'}, {bubbles: true});
    </script>
  </head>
</html>

In a Polymer 3 element

import {PolymerElement, html} from '@polymer/polymer';
import {IronA11yAnnouncer} from '@polymer/iron-a11y-announcer/iron-a11y-announcer.js';

class SampleElement extends PolymerElement {
  static get template() {
    return html`
      <button on-click="announce">Announce</button>
    `;
  }
  function attached() {
    IronA11yAnnouncer.requestAvailability();
  }

  // After the `iron-a11y-announcer` has been made available, elements can
  // make announces by firing bubbling `iron-announce` events.
  // Note: announcements are only audible if you have a screen reader enabled.
  function announce() {
    IronA11yAnnouncer.instance.fire('iron-announce',
        {text: 'Hello there!'}, {bubbles: true});
  }
}
customElements.define('sample-element', SampleElement);

Contributing

If you want to send a PR to this element, here are the instructions for running the tests and demo locally:

Installation

git clone https://github.com/PolymerElements/iron-a11y-announcer
cd iron-a11y-announcer
npm install
npm install -g polymer-cli

Running the demo locally

polymer serve --npm
open http://127.0.0.1:<port>/demo/

Running the tests

polymer test --npm

Known Issues

This element doesn't work on Firefox (it doesn't read anything in Voice Over), since aria-live has been broken since the Quantum redesign (see the MDN docs demo) -- we tested it on Firefox 60, but it doesn't look like a regression, so it's probably broken on older versions as well.