Angular 2 resolver with loading indicator

You can use the “reacting to routing events” strategy that consist to implement the App to react when any routing event occurs. To do that, you will need in your app.component.ts some code like:

import { Component } from '@angular/core';
import { Router, RouterEvent, NavigationStart, NavigationEnd, NavigationError, NavigationCancel } from '@angular/router';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.sass']
})
export class AppComponent {

  loading: boolean = true;

  constructor(private router: Router) {
    router.events.subscribe((routerEvent: RouterEvent) => {
      this.checkRouterEvent(routerEvent);
    });
  }

  checkRouterEvent(routerEvent: RouterEvent): void {
    if (routerEvent instanceof NavigationStart) {
      this.loading = true;
    }

    if (routerEvent instanceof NavigationEnd ||
      routerEvent instanceof NavigationCancel ||
      routerEvent instanceof NavigationError) {
      this.loading = false;
    }
  }
}

And in the view(html) something like:

<div id="loader" class="myloader" *ngIf="loading">
  Loading...
</div>