Stackoverflow 51335491

controllers.application.js

import Ember from 'ember';
import { computed } from '@ember/object';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  dynamicPart: 'foo',
  row: computed(() => {
    return {
      'foo': {
        'key': 'foo value'
      },
      'bar': {
        'key': 'bar value'
      }
    };
  })
});

templates.application.hbs

<h1>Composition of get and concat helpers</h1>
<p>A proof of concept for <a href="https://stackoverflow.com/questions/51335491/how-do-i-access-object-property-in-handlebars-template">this StackOverflow question</a>.</p>
<p>
  {{get row (concat dynamicPart '.key')}}
  <br>
  <button onclick={{action (mut dynamicPart) 'bar'}}>show bar value</button>
</p>

twiddle.json

{
  "version": "0.15.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.2.2",
    "ember-template-compiler": "3.2.2",
    "ember-testing": "3.2.2"
  },
  "addons": {
    "ember-data": "3.2.0"
  }
}