angular-docs-cn/public/docs/_examples/router/ts/app/auth.service.ts

// #docregion
import { Injectable } from '@angular/core';

import { Observable } from 'rxjs/Observable';
import 'rxjs/add/observable/of';
import 'rxjs/add/operator/do';
import 'rxjs/add/operator/delay';

@Injectable()
export class AuthService {
  isLoggedIn: boolean = false;

  // store the URL so we can redirect after logging in
  redirectUrl: string;

  login() {
    return Observable.of(true).delay(1000).do(val => this.isLoggedIn = true);
  }

  logout() {
    this.isLoggedIn = false;
  }
}