ED tracked

controllers.application\.js

import Controller from '@ember/controller';
import { action, computed, set } from '@ember/object';

export default class ApplicationController extends Controller {
  get nonComputedMessage() {
  	return this.model.message;
  }
  
  @computed('model.message')
  get computedMessage() {
  	return this.model.message;
  }
  
  @action
  changeMessage() {
    set(this.model, 'message', 'helló világ');
  }
}

routes.application\.js

import Route from '@ember/routing/route';

export default class ApplicationRoute extends Route {
	model() {
  	return {
    	message: "Hello world."
    }
  }
}

templates.application\.hbs

<h1>Welcome to {{this.appName}}</h1>
<br>
Directly from model: {{this.model.message}}
<br>
Non-computed getter: {{this.nonComputedMessage}}
<br>
Computed getter: {{this.computedMessage}}
<br>
<button {{on "click" (fn (mut this.model.message) "viszlát")}}>Change from template</button>
<button {{on "click" (action this.changeMessage)}}>Change from action</button>

{{outlet}}
<br>
<br>

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"
  }
}