Within this section, we're going to use the navigation components we've just created to provide a project navigation. For this, we're first going to introduce the necessary changes in the app component class located in src/main/app/app.component.ts. This is the first time we are dealing with the app or root component class. Since this is our root component, we're treating it like a container component, and it gets the privileges to deal with state and data:
import {Component, ViewEncapsulation} from '@angular/core';import {Observable} from 'rxjs';import {Project} from './model';import {ProjectService} from './project/project.service';@Component({ selector: 'mac-root', templateUrl: './app.component.html', styleUrls: ...