title: Angular 2 prevent non auth user access route and child
body: <p>There is the structure of our project:</p>
  
  <ul>
  <li>AppComponent
  
  <ul>
  <li>Nav Component</li>
  <li>LoginComponent</li>
  </ul></li>
  </ul>
  
  <p>After the user has authenticated using the form, which calls Firebase, then the user must be redirected to the part only accessible to logged-in users.</p>
  
  <ul>
  <li>AccountComponent
  
  <ul>
  <li>ProfileComponent</li>
  <li>FilesComponent</li>
  </ul></li>
  </ul>
  
  <p>As you can see the account component has two childs.</p>
  
  <p><strong>I'm looking for a proper way to prevent un-auth users to access the protected area of my website</strong> and don't know if I have to call the authService <strong>in a component (appComponent ? AccountComponent? OnInit of one of the component?) OR in the routes definition</strong> with a CanActivate or CanActivateChild ?</p>