My Accordion

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  
  myAccordianConfig: Ember.computed(function() {
    return [
      {
        label: 'numero uno',
        isExpanded: false,
        children: [
          {
            label: '1.1',
            isExpanded: true,
          }
        ]
      },
      {
        label: '222',
        isExpanded: false,
      },
    ];
  }),

  
  actions: {
    expandAll() {
      this.get('myAccordianConfig').setEach('isExpanded', true);
    },
    collapseAll() {
      this.get('myAccordianConfig').setEach('isExpanded', false);
    },
  }
});

my-accordion.component.js

import Ember from 'ember';

export default Ember.Component.extend({
  configuration: undefined,
  actions: {
    onExpand(item) {
      Ember.set(item, 'isExpanded', !item.isExpanded);
    },
  },
});

my-accordion.template.hbs

{{#each configuration as |item|}}
  <h3 {{action 'onExpand' item}}>
    {{item.label}}
    {{if item.isExpanded '+' '–'}}
  </h3>

  {{#if item.isExpanded}}
    {{yield}}
  {{/if}}
{{/each}}

templates.application.hbs

<button {{action 'expandAll'}}>Expand all</button>
<button {{action 'collapseAll'}}>Collapse all</button>

{{#my-accordion
  configuration=myAccordianConfig
  as |accordion|
}}
	{{#accordion.header}}
  	Hello World
	{{/accordion.header}}
{{/my-accordion}}

twiddle.json

{
  "version": "0.14.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": true,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "2.18.2",
    "ember-template-compiler": "2.18.2",
    "ember-testing": "2.18.2"
  },
  "addons": {
    "ember-data": "2.18.2"
  }
}