从 canActivate 方法返回一个 Observable<boolean> 并在 false 时重定向

Question

我一直在寻找解决方案，但没有成功。如果用户获得授权，我需要调用服务器，并且我需要 canActivate 方法来等待该调用的结果。但我似乎无法将各个部分拼凑起来。下面是我的代码，我的问题在代码的注释中。

  canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<boolean> {

    let user: EUser = new EUser();
    user.sessionId = localStorage.getItem("sessionId");

    //I am not sure how to implement this part. 
    // I need to recieve the response and get user.isAuthorized value and return it
    // as an observable. 
    this.authenticationService.isAuthorized(user).subscribe((user)=>{
        //Here i need to get user.isAuthorized and 
        //if the value is false, i need to navigate to login with this.router.navigate['login'] and return it. 
        //if the values it true, i need the code continue as it is. 
    });

  }

身份验证服务

isAuthorized(user:EUser){
    return this.http.post(ConnectionHelper.SERVER_URL+
          ConnectionHelper.USER+ConnectionHelper.ISAUTHORIZED,user).map(res => res.json());
}

Answer 1

您的方法是正确的，您只需要将服务器响应映射到一个 bool 值。例如：

export interface AuthState {
    username:string;
    sessionId:string;
    isAuthorized:boolean;
}

isAuthorized(user:EUser): Observable<AuthState> {
    return this.http.post(ConnectionHelper.SERVER_URL+
          ConnectionHelper.USER+ConnectionHelper.ISAUTHORIZED,user)
    .map(res => res.json());
}

// Inject Router instance in the constructor of the guard class
// import required rxjs operators
canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<boolean> {
    let user: EUser = new EUser();
    user.sessionId = localStorage.getItem("sessionId");
    return this.authenticationService.isAuthorized(user)
    .map(user => user.isAuthorized)
    .do(auth => {
      if(!auth){
         this.router.navigate(['/login']);
      }
    });
}

Answer 2

您可以再次使用 promise 和 return value 在 canActivate 中使用。如果假设 isAuthorized return boolean 值，您可以使用此代码：

canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<boolean> {

let user: EUser = new EUser();
user.sessionId = localStorage.getItem("sessionId");

return this.authenticationService.isAuthorized(user)
  .toPromise()
  .then((isValidUser) => {

    if (!isValidUser) {
      this.router.navigate['login'];
    }
    return isValidUser;
  });

}

请注意，then 链 return Promise 再次 return isValidUser 可在下一个 then 调用中访问。

我使用这个模式并且它对我有用。

从 canActivate 方法返回一个 Observable<boolean> 并在 false 时重定向

Returning an Observable<boolean> from canActivate method and redirect on false

angular

rxjs

angular-router

angular-router-guards