New Twiddle

components.child-component.js

import Ember from 'ember';

export default Ember.Component.extend({
  tagName: 'button',
  // On click we call the action passed down to us from the parent
  click() {
    let data = this.get('data');
    this.get('onaction')(data); 
  }
});

components.parent-component.js

import Ember from 'ember';

export default Ember.Component.extend({
  actions: {
    // We pass this action to the child to call at it's discretion
    parentAction(childData) {
      // alert('Data from child-component: ' + childData);
      console.log(childData);
    }
  }
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  // ui: Ember.Object.create([{id:1, item:7}, {id:2, item: 9}]),
	// model: Ember.Object.create([{id:1, item:7}, {id:2, item: 9}])
  model: [{id:1, item:7}, {id:2, item: 9}]
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
{{#parent-component as |ui|}}
  {{#each model as |item index|}}
  {{log ui.child }}
    {{ui.child data=item index=index}}
  {{/each}}
{{/parent-component}}
<br>
<br>

templates.components.child-component.hbs

Button {{index}}

templates.components.parent-component.hbs

{{yield (hash
   child=(
     component 'child-component'
     onaction=(action 'parentAction')
   )
)}}

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"
  }
}