Consumer Code Organization

components.consumer-container.js

import Ember from 'ember';

export default Ember.Component.extend({
  tagName: '',
  
  // Change this to true to render modal component! You can write computed prop and house this logic within this component to render child components similarly.
  _hasModal: false,
  
});

components.consumer-modal.js

import Ember from 'ember';

export default Ember.Component.extend({
  classNames:['consumer-modal'],
});

controllers.application.js

import Ember from 'ember';

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

styles.app.css

body {
  margin: 12px 16px;
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  font-size: 12pt;
}

.consumer-modal {
  color: red;
}

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}

{{#consumer-container as |args|}}
  {{args.modal}}
{{/consumer-container}}
<br>
<br>

templates.components.consumer-container.hbs

<p>I have a modal but you need to set it to true in consumer-container.js file to see it!</p>
{{yield (hash modal=(if _hasModal (component "consumer-modal")))}}

templates.components.consumer-modal.hbs

I am a modal.
{{yield}}

twiddle.json

{
  "version": "0.15.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.4.3",
    "ember-template-compiler": "3.4.3",
    "ember-testing": "3.4.3"
  },
  "addons": {
    "ember-data": "3.4.2"
  }
}