Ember Extend Leak State

components.lock-her-up.js

import Ember from 'ember';

export default Ember.Component.extend({
  tagName: 'li',
  
  prisoners: [],
  
  actions: {
    enprison(person) { 
      this.get('prisoners').pushObject(person);
    },
    free(person) {
      this.get('prisoners').removeObject(person);
    }
  }
});

controllers.application.js

import Ember from 'ember';

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

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
<div>
  We expect that clicking "Lock up" will only lock up our criminal in one place, however, try clicking and see what happens!
</div>
<div>
  <h2>Federal Prison</h2>
  {{lock-her-up}}
</div>
<div>
  <h2>State Prison</h2>
  {{lock-her-up}}
</div>
<br>
<br>

templates.components.lock-her-up.hbs

{{yield}}
{{#each prisoners as |prisoner|}}
  <li>{{prisoner}}</li>
{{/each}}

<li>
  <button onclick={{action 'enprison' 'Hillary Clinton'}}>
    Lock up
  </button>
</li>

twiddle.json

{
  "version": "0.13.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.16.2",
    "ember-template-compiler": "2.16.2",
    "ember-testing": "2.16.2"
  },
  "addons": {
    "ember-data": "2.16.3"
  }
}