Slack example

application.controller.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle'
});

application.template.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{#comp-1 as |options|}}
  {{comp-2 contentChanged=options.contentChanged}}
{{/comp-1}}
<br>
<br>

comp-1.component.js

import Ember from 'ember';

export default Ember.Component.extend({
  actions:{
  	contentChanged(){
      this.set('result','yey!');
    }
  }
});

comp-1.template.hbs

{{result}}
{{yield (hash contentChanged=(action 'contentChanged'))}}

comp-2.component.js

import Ember from 'ember';

export default Ember.Component.extend({
  actions:{
    contentChanged(){
      this.get('contentChanged')();
    }
  }
});

comp-2.template.hbs

<button {{action 'contentChanged'}}>click me</button>

twiddle.json

{
  "version": "0.6.5",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.4.3/ember.debug.js",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.4.0/ember-data.js",
    "ember-template-compiler": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.4.3/ember-template-compiler.js"
  }
}