Component Inheritance

components.alpha-panel\.js

import Component from '@glimmer/component';
import { tracked } from '@glimmer/tracking';
import { action } from '@ember/object';

export default class extends Component {
  @tracked isOpen = false;

  @action
  togglePanel() {
    this.isOpen = !this.isOpen;
  }
}

components.beta-panel\.js

import Component from '@glimmer/component';
import AlphaPanel from './alpha-panel';

export default class extends AlphaPanel {}

styles.app\.css

body {
  margin: 12px 16px;
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  font-size: 12pt;
}

.panel {
  border: 1px solid grey;
  border-radius: 4px;
  padding: 10px 15px;
}

.panel-header {
  cursor: pointer;
}

.panel-body {
  padding: 10px 0 0;
}

templates.application\.hbs

<AlphaPanel />
<br>
<BetaPanel />

templates.components.alpha-panel\.hbs

{{!--

  Component inheritance
  Mixins - clobbering, not standard in JS
  Testing - do I retest everything or just my differing logic?

--}}
<div class="panel">
  <div
  	class="panel-header"
    style="background: {{if this.isOpen "lightblue"}}"
    {{on "click" this.togglePanel}}
  >
  	Alpha header
  </div>
  {{#if this.isOpen}}
    <div class="panel-body">
      Alpha body
    </div>
  {{/if}}
</div>

templates.components.beta-panel\.hbs

<div class="panel">
  <div
  	class="panel-header"
    style="background: {{if this.isOpen "hotpink"}}"
    {{on "click" this.togglePanel}}
  >
  	Beta header
  </div>
  {{#if this.isOpen}}
    <div class="panel-body">
      Beta body
    </div>
  {{/if}}
</div>

twiddle\.json

{
  "version": "0.17.1",
  "EmberENV": {
    "FEATURES": {},
    "_TEMPLATE_ONLY_GLIMMER_COMPONENTS": false,
    "_APPLICATION_TEMPLATE_WRAPPER": true,
    "_JQUERY_INTEGRATION": true
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.js",
    "ember": "3.18.1",
    "ember-template-compiler": "3.18.1",
    "ember-testing": "3.18.1"
  },
  "addons": {
    "@glimmer/component": "1.0.0"
  }
}