New Twiddle

components.item-component.js

import Ember from 'ember';

export default Ember.Component.extend({
	init() {
    this._super(arguments);
  	console.log(`init called on component with id ${this.get('item.id')}`);
  }
});

components.main-component.js

import Ember from 'ember';

export default Ember.Component.extend({
  selectedIndex: 0,
	specialItems: Ember.computed('items', 'selectedIndex', function() {
    const items = this.get('items');
  	return items.map((item, index) => {
    	return {
      	title: item.title,
        id: item.id,
        isSelected: index === this.get('selectedIndex')
      };
    });
  }),
  actions: {
  	next() {
    	this.set('selectedIndex', this.get('selectedIndex') + 1);
    }
  }
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  init() {
  	this.items = [
      {
      	title: 'Item one',
        id: 1
      },
      {
      	title: 'Item two',
        id: 2
      },
      {
      	title: 'Item three',
        id: 3
      }
    ];
  }
});

templates.application.hbs

<p>Open the console. Notice that there are 3 instances of item-component intialized. Click "next", and all of the item-components are all reinitialized.</p>

{{main-component items=items}}

templates.components.item-component.hbs

{{#if item.isSelected}}
	<h1>{{item.title}}</h1>
{{/if}}

templates.components.main-component.hbs

{{#each specialItems key="id" as |item|}}
	{{item-component item=item}}
{{/each}}

<button {{action "next"}}>Next</button>

twiddle.json

{
  "version": "0.12.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.12.0",
    "ember-template-compiler": "2.12.0",
    "ember-testing": "2.12.0"
  },
  "addons": {
    "ember-data": "2.12.1"
  }
}