New Twiddle

components.user-display.js

import Ember from 'ember';

export default Ember.Component.extend({
  greeting: 'Hi',
  nameInternal: null,
  go: null
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  name: null,
  
  fullName: Ember.computed('model.firstName', 'model.lastName', function() {
    return this.get('model.lastName') + ', ' + this.get('model.firstName')
  }),
  
  greeting: Ember.computed('fullName', function() {
    return 'Hello, ' + this.get('fullName')
  }),
  
  actions: {
   changeName() {
     this.set('model.firstName', this.get('name'))
   }
  }
});

controllers.user.js

import Ember from 'ember';

export default Ember.Controller.extend({
  fullName: Ember.computed('model.firstName', 'model.lastName', function() {
    return this.get('model.lastName') + ', ' + this.get('model.firstName')
  }),
  
  greeting: Ember.computed('fullName', function() {
    return 'Hello, ' + this.get('fullName')
  })
});

router.js

import Ember from 'ember';
import config from './config/environment';

const Router = Ember.Router.extend({
  location: 'none'
});

Router.map(function() {
  this.route('user', function() {
    this.route('profile')
  })
  this.route('another')
});

export default Router;

routes.application.js

import Ember from 'ember';

export default Ember.Route.extend({
    model() {
    return {
      firstName: 'Steven',
      lastName: 'Glanzer'
    }
  }
});

routes.user.js

import Ember from 'ember';

export default Ember.Route.extend({
  model() {
    return {
      firstName: 'Steven',
      lastName: 'Glanzer'
    }
  }
});

templates.application.hbs

<div>
  {{greeting}}
</div>
<div>
  {{input type='text' value=name}}{{name}}
</div>
<button onclick={{action 'changeName'}}>Do stuff</button>

{{#user-display nameInternal=fullName go=(action 'changeName')}}
asdf
{{/user-display}}

templates.components.user-display.hbs

{{greeting}} {{nameInternal}}
<button onclick={{action go}}>Go</button>

{{yield}}

templates.user.hbs

{{greeting}}
{{outlet}}

templates.user.profile.hbs

abcd

twiddle.json

{
  "version": "0.7.2",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "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/2.4.4/ember.debug.js",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.4.3/ember-data.js",
    "ember-template-compiler": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.4.4/ember-template-compiler.js"
  }
}