Angular2 CanActivate后卫无法正常工作

Question

我正在使用Observable<boolean>返回canActivate().设置了以下功能进行测试,并且正确解析,显示组件.

canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<boolean> {
  return Observable.from([{ admin: true }]).map(x =>
  {
    if (x.admin) return true;
    return false;
  });
}

但是,实际代码的行为是我保留在登录组件上,尽管控制台输出指示应该激活路由.上面测试的唯一真正区别是我正在调用服务this.auth.isAdmin()而不是使用Observable.from.结果this.auth.isAdmin()是Observable<boolean>值为true.

canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<boolean> {
  const isAdmin$ = this.auth.isAdmin();
  return isAdmin$.map(x =>
  {
    console.log('isAdmin returned ' + x);
    if (!x) {
      console.log('redirectToLogin');
      this.auth.redirectToLogin(state.url);
      return false;
    } else {
      console.log('canActivate = true');
      return true;
    }
  });  
}

这是路由:

{
  path: 'admin',
  canActivate: [AdminGuard],
  children: [
    ...adminRoutes
  ]
},

这是我的控制台输出:

isAdmin returned false
admin-guard.service.ts:27redirectToLogin
auth.service.ts:36 navigating to stored path "/admin"
auth.service.ts:21 Object {isAdmin: true, isPaid: false, $key: "xYFs8kMDpKdYKxDw4AL21FtnSWn1"}
admin-guard.service.ts:25 isAdmin returned true
admin-guard.service.ts:31 canActivate = true

以下是感兴趣的isAdmin()函数:

isAdmin(): Observable<boolean> {
    if (!this.auth) return Observable.from([false]);
    const uid = this.auth.uid;
    return this.af.database.object(`user/${uid}`).do(x => console.log(x)).map(x => x.isAdmin);
}

Answer 1

您的isAdmin函数返回的可观察量未完成.AngularFire2 FirebaseObjectObservable实例未完成; 它们在底层数据发生变化时发出对象.

守卫归来的观察者必须完成.您可以通过在发出第一个值时使用first(或take(1))来完成observable 来确保这一点:

canActivate(
  route: ActivatedRouteSnapshot,
  state: RouterStateSnapshot
): Observable<boolean> {
  const isAdmin$ = this.auth.isAdmin();
  return isAdmin$.first().map(x =>
  {
    console.log('isAdmin returned ' + x);
    if (!x) {
      console.log('redirectToLogin');
      this.auth.redirectToLogin(state.url);
      return false;
    } else {
      console.log('canActivate = true');
      return true;
    }
  });  
}

在撰写本文时,返回的observable必须完成.但是,Angular现在调用 返回的observable,因此不再需要observable来完成.first