didInsertElement Example

components.item-component.js

import Component from '@ember/component';

export default class ItemComponent extends Component {
  didInsertElement() {
    console.log(`item ${this.item} was inserted`); 
  }
}

components.item-list.js

import Component from '@ember/component';

export default class ItemList extends Component {
  didInsertElement() {
    console.log('list was inserted'); 
  }
}

controllers.application.js

import Controller from '@ember/controller';

export default class ApplicationController extends Controller {
  appName = 'Ember Twiddle';
  
  items = [
    1,
  	2,
  	3,
  	4,
  	5,
  ]
}
 

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{!-- 
  or {{item-list items=this.items}} 
  if not using angle-bracket invocation
--}}
<ItemList @items={{this.items}} />
<br>
<br>

templates.components.item-component.hbs

<hr>
  {{!-- 
    or {{item}} 
    if not using angle-bracket invocation
  --}}
  {{@item}}
<hr> 

templates.components.item-list.hbs

 {{!-- 
  or {{#each items as |item|}} 
  if not using angle-bracket invocation
--}}

 {{#each @items as |item|}}
 
   {{!-- 
     or {{item-component item=item}} 
     if not using angle-bracket invocation
   --}}
   <ItemComponent @item={{item}} />
  
 {{/each}}

twiddle.json

{
  "version": "0.15.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": true,
    "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"
  }
}