coral-spectrum/coral-component-anchorbutton/src/scripts/AnchorButton.js
/**
* Copyright 2019 Adobe. All rights reserved.
* This file is licensed to you under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License. You may obtain a copy
* of the License at http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under
* the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS
* OF ANY KIND, either express or implied. See the License for the specific language
* governing permissions and limitations under the License.
*/
import {BaseComponent} from '../../../coral-base-component';
import {BaseButton} from '../../../coral-base-button';
import {transform, commons} from '../../../coral-utils';
import {Decorator} from '../../../coral-decorator';
// Key code
const SPACE = 32;
/**
@class Coral.AnchorButton
@classdesc A Link component rendering as a button allowing us to style an anchor element that both looks and behaves
like a button rather than a link. It can receive keyboard focus regardless of whether or not it has an <code>href</code>
attribute, can be activated using either the <code>SPACE</code> key or the <code>ENTER</code> key, and is identified to
assistive technology as a button element.
@htmltag coral-anchorbutton
@htmlbasetag a
@extends {HTMLAnchorElement}
@extends {BaseComponent}
@extends {BaseButton}
*/
const AnchorButton = Decorator(class extends BaseButton(BaseComponent(HTMLAnchorElement)) {
/** @ignore */
constructor() {
super();
// Events
this._delegateEvents(commons.extend(this._events, {
keydown: '_onKeyDown',
keyup: '_onKeyUp'
}));
// cannot use the events hash because events on disabled items are not reported
this.addEventListener('click', this._onDisabledClick.bind(this));
}
/**
Disables the button from user interaction.
@type {Boolean}
@default false
@htmlattribute disabled
@htmlattributereflected
*/
get disabled() {
return this._disabled || false;
}
set disabled(value) {
this._disabled = transform.booleanAttr(value);
this._reflectAttribute('disabled', this._disabled);
this.classList.toggle('is-disabled', this._disabled);
this.setAttribute('tabindex', this._disabled ? '-1' : '0');
this[this._disabled ? 'setAttribute' : 'removeAttribute']('aria-disabled', this._disabled);
}
/**
Keyboard handling per the WAI-ARIA button widget design pattern:
https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/ARIA_Techniques/Using_the_button_role
@ignore
*/
_onKeyDown(event) {
if (event.keyCode === SPACE) {
event.preventDefault();
this.click();
this.classList.add('is-selected');
}
}
/** @ignore */
_onKeyUp(event) {
if (event.keyCode === SPACE) {
event.preventDefault();
this.classList.remove('is-selected');
}
}
/** @ignore */
_onDisabledClick(event) {
if (this.disabled) {
event.preventDefault();
}
}
// Override content zone name
get _contentZones() {
return {'coral-anchorbutton-label': 'label'};
}
/** @ignore */
static get observedAttributes() {
return super.observedAttributes.concat(['disabled']);
}
/** @ignore */
render() {
super.render();
// a11y
this.setAttribute('role', 'button');
if (!this.disabled) {
// Force tabindex and aria-disabled attribute reflection
this.setAttribute('tabindex', '0');
this.removeAttribute('aria-disabled');
}
}
});
export default AnchorButton;