autotracking, EmberObject

controllers.application\.js

import Controller from '@ember/controller';
import EmberObject, { action, get, set } from '@ember/object';
import { cached } from '@glimmer/tracking';

export default class ApplicationController extends Controller {
  obj = EmberObject.extend({ someFlag: false }).create();

  // 1. call `setFlag()`
  // -> rendered in template as `false` (not updated)
  get someFlag() {
    return this.obj.someFlag;
  }

  // 1. call `setFlag()`
  // -> rendered in template as `true`
  get someFlagEmberGet() {
    return get(this.obj, 'someFlag');
  }

  // 1. call `setFlag()`
  // -> rendered in template as `false` (not updated)
  @cached
  get cachedSomeFlagEmberGet() {
    return get(this.obj, 'someFlag');
  }

  @action
  setFlag() {
    set(this.obj, 'someFlag', true);
  }
}

templates.application\.hbs

<p>someFlag: {{this.someFlag}}</p>
<p>someFlagEmberGet: {{this.someFlagEmberGet}}</p>
<p>cachedSomeFlagEmberGet: {{this.cachedSomeFlagEmberGet}}</p>
<button {{on "click" this.setFlag}}>set flag</button>

{{outlet}}

twiddle\.json

{
  "version": "0.17.1",
  "EmberENV": {
    "FEATURES": {},
    "_TEMPLATE_ONLY_GLIMMER_COMPONENTS": false,
    "_APPLICATION_TEMPLATE_WRAPPER": true,
    "_JQUERY_INTEGRATION": true
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.js",
    "ember": "3.18.1",
    "ember-template-compiler": "3.18.1",
    "ember-testing": "3.18.1"
  },
  "addons": {
    "@glimmer/component": "1.0.0",
    "ember-cached-decorator-polyfill": "^0.1.4"
  }
}