New Twiddle

components.my-component.js

import Component from '@ember/component';

export default Component.extend({

});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  init(){
    this._super(...arguments);
    this.clickedPeople = [];
  },
  actions: {
    onPersonClick(person){
      this.clickedPeople.pushObject(person);
    },
    
    onPersonClickWithConfirm(person){
      if(confirm("Are you sure?")) {
        this.clickedPeople.pushObject(person);
      }
    }

  }
});

routes.application.js

import Ember from 'ember';

export default Ember.Route.extend({
  model(){
    return ['Marie Curie', 'Mae Jemison', 'Albert Hofmann']; 
  }
});

templates.application.hbs

Without confirm:
{{my-component people=model onPersonClick=(action 'onPersonClick')}}

With confirm:
{{my-component people=model onPersonClick=(action 'onPersonClickWithConfirm')}}

<h1>Cicked people</h1>
<ul>
{{#each clickedPeople as |person|}}
  <li>{{person}}</li>
{{/each}}
</ul>

templates.components.my-component.hbs

<h2>{{title}}</h2>

<ul>
  {{#each people as |person|}}
    {{!-- <li>{{person}}</li> --}}
    <li {{action onPersonClick person}}>{{person}}</li>
  {{/each}}
</ul>

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"
  }
}