app.component.html

<div class="app-container">
  <app-header></app-header>
  <div (scroll)="onScrollDown($event)" class="app-body">
    <router-outlet></router-outlet>
    <router-outlet name="print"></router-outlet>
    <!-- <app-footer>
      commented to use outlet in another branch
    </app-footer> -->
  </div>
</div>