New Twiddle

components.child-component.js

import Ember from 'ember';

export default Ember.Component.extend({
  init() {
    console.log("in child component");
    this._super(...arguments);
  },
  
  didInsertElement() {
    this.sendAction("changeAction");
  },
  
    didRender() {
    this._super(...arguments);
    console.log("in child component didRender");
  },
});

components.parent-component.js

import Ember from 'ember';

export default Ember.Component.extend({
  flagValue: false,
  name: null,
  
  didReceiveAttrs() {
    this._super(...arguments);
    console.log("in parent component didReceive");
  },
  
  didRender() {
    this._super(...arguments);
    console.log("in parent component didRender");
    this.set('name' , "mary");
  },
  actions: {
    changeProperty() {
      console.log("change property action triggered");
      this.set('flagValue', true);
      this.set('name', "bhavya bansal");
    }
  }
});

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>
{{parent-component}}
<br>
<br>

templates.components.child-component.hbs

{{yield}}
<p> in child component </p>
{{log name}}

templates.components.parent-component.hbs

{{yield}}
<p> in parent component </p>
{{child-component  name=name changeAction=(action "changeProperty")}}

{{#if flagValue}}
  {{log 'flag value changed'}}
{{/if}}  

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"
  }
}