Query params and fragment

In opposite to other observables, that are scoped to a particular route, query parameters and fragment are shared across multiple routes.

@Component({...})
class MessageCmp {
  debug: Observable <string>;
  fragment: Observable <string>;

  constructor(route: ActivatedRoute) {
    this.debug = route.queryParams.map(p => p.debug);
    this.fragment = route.fragment;
  }
}