import { Component , ChangeDetectorRef } from "@angular/core" ; @ Component ( { selector : 'Todo1' , template : ` <div>
                    <small>I am the todo1 component</small>
                   <br/>
                    <br/>
                     <button type="button" (click)="onForceDetection()" class="btn btn-default btn-sm goNext">
                        Force change detection on component;
                    </button>
                    <ng-content></ng-content>
                    </div>
                ` } ) export class Todo1 { constructor ( private cd ) { } private onForceDetection ( ) { this . cd . markForCheck ( ) ; } }