当守卫返回可观察对象时，角度路由器不起作用

Question

我想重定向未登录的用户，当他们尝试访问受保护的路由但重定向不起作用时，因为检查用户是否已登录的函数返回可观察量。

这是我在PrivateGuard中的代码：

import { Injectable } from '@angular/core';
import { CanActivate, ActivatedRouteSnapshot, RouterStateSnapshot, Router } from '@angular/router';
import { Observable } from 'rxjs';
import { map } from 'rxjs/operators';
import { AmplifyService } from 'aws-amplify-angular';
@Injectable({
  providedIn: 'root'
})
export class PrivateGuard implements CanActivate {
  constructor (private _router: Router,
               private _amplifyService: AmplifyService) {}
  canActivate(next: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<boolean> | Promise<boolean> | boolean {
    return this._amplifyService.authStateChange$.pipe(map(authState => {
        console.log(authState);
        if (authState.state === 'signedIn')  {
          return true;
        }else{
          this._router.navigate(['/login']); // Why Never redirect?
          return false;
        }
      })
    );
  }
}

app.routes.ts：

import { RouterModule, Routes } from '@angular/router';
import { LoginComponent } from './components/public/login/login.component';
import { HomeComponent } from './components/private/home/home.component';
const APP_ROUTES: Routes = [
  { path: 'login', component: LoginComponent},
  { path: 'home', component: HomeComponent, canActivate: [PrivateGuard] },
  { path: '**', pathMatch: 'full', redirectTo: 'home' }
];
export const APP_ROUTING = RouterModule.forRoot(APP_ROUTES);

如果我在登录时编写 console.log in else 语句，则此控制台.log将显示在控制台中，但永远不会重定向到 homeComponent

当我尝试导航到专用路由时控制台

url 中的路由消失了，而不是本地主机：4200/登录

感谢您的任何回复。

解决

最后，我使用承诺而不是可观察的。代码如下：

import { Injectable } from '@angular/core';
import { CanActivate, ActivatedRouteSnapshot, RouterStateSnapshot, Router } from '@angular/router';
import { AmplifyService } from 'aws-amplify-angular';
import { Observable } from 'rxjs';
@Injectable({
  providedIn: 'root'
})
export class PrivateGuard implements CanActivate {
  constructor (private _router: Router,
               private _amplifyService: AmplifyService) {}
  canActivate(next: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<boolean> | Promise<boolean> | boolean {
    return this._amplifyService.auth().currentAuthenticatedUser()
      .then(() => {
        return true;
      })
      .catch(() => {
        this._router.navigate(['/login']);
        return false;
      });
  }
}

谢谢大家的回答

Answer 1

你的可观察量可能永远不会完成，它仍然等待 authStateChange$ 发出更多值。

您可以使用 take 运算符实现您想要的(该运算符将在发出一个值后取消订阅：

return this._amplifyService.authStateChange$.pipe(
   take(1), // completes the observable on first emited value
   map(authState => /* */)
);