Question

我很难弄清楚这个错误。这是我用来建立AuthGuard服务的代码：

user.service.ts:

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

import { AngularFireDatabase, AngularFireList } from 'angularfire2/database';

import {AppUser} from './models/app.user';
import * as firebase from 'firebase';

@Injectable({
  providedIn: 'root'
})
export class UserService {

  constructor(private db: AngularFireDatabase) { }

  save(user: firebase.User) {
    this.db.object('/users/' + user.uid).update({
      name: user.displayName,
      email: user.email
    });
  }

  get(uid: string): AngularFireList<AppUser> {
    return this.db.list('/users/' + uid).valueChanges();
  }
}

属性.valueChanges()向我显示错误：

：>类型“可观察的<{} []>

中缺少属性“查询”

我也遇到获取uid的问题：

in AuthGuardService.ts:

import { Injectable } from '@angular/core';
import { Observable } from 'rxjs/observable';
import 'rxjs/add/operator/switchMap';
import 'rxjs/operator/map';
import { UserService } from './user.service';
import { CanActivate } from '@angular/router';
import { AuthService } from './auth.service';



@Injectable({
  providedIn: 'root'
})
export class AdminAuthGuard implements CanActivate {

  constructor(private auth: AuthService, private userService: UserService) { }

  canActivate (): Observable<boolean> {
    return this.auth.user$
      .switchMap(user => this.userService.get(user.uid).valueChanges())
      .map (appUser => appUser.isAdmin);
  }
}

错误是：

消息”：“类型'AppUser []'上不存在属性'isAdmin'。”

app.user.ts：

export interface AppUser {
    name: string;
    email: string;
    isAdmin: boolean;
}

有人可以帮助我确定如何解决此问题吗？谢谢！

Answer 1

在您的服务中，您的退货类型错误。您没有返回AngularFireList<AppUser>，而是返回Observable<AppUser[]>。

在守护程序中，您要传递一组要映射的用户，因此您必须检查第一个元素是否是admin。

我对firebase不太熟悉，但在您的情况下，似乎db.list()的更合适选择是db.object()以返回单个记录：

/* service */
get(uid: string): Observable<AppUser> {
    return this.db.object<AppUser>('/users/' + uid).valueChanges();
}

/* guard */
canActivate (): Observable<boolean> {
    return this.auth.user$
       .switchMap(user => this.userService.get(user.uid))
       .map (appUser => appUser.isAdmin);
}

Answer 2

我找到了答案：

user.service.ts:

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

import { AngularFireDatabase, AngularFireObject } from 'angularfire2/database';

import {AppUser} from './models/app.user';
import * as firebase from 'firebase';
import { Observable } from 'rxjs';

@Injectable({
  providedIn: 'root'
})
export class UserService {


  constructor(private db: AngularFireDatabase) { }

  save(user: firebase.User) {
    this.db.object('/users/' + user.uid).update({
      name: user.displayName,
      email: user.email
    });
  }

  get(uid: string): AngularFireObject<AppUser> {
      return this.db.object('/users/' + uid);
  }

}

In admin-auth-guard.service.ts:

import { Injectable } from '@angular/core';
import { Observable } from 'rxjs/observable';
import 'rxjs/add/operator/switchMap';
import 'rxjs/operator/map';
import { UserService } from './user.service';
import { CanActivate } from '@angular/router';
import { AuthService } from './auth.service';




@Injectable({
  providedIn: 'root'
})
export class AdminAuthGuard implements CanActivate {

  constructor(private auth: AuthService, private userService: UserService) { }

   canActivate(): Observable<boolean> {
      return this.auth.user$
      .switchMap(user => this.userService.get(user.uid).valueChanges())
      .map (appUser => appUser.isAdmin);
     }
}

谢谢大家！

AngularFireList，属性valueChanges（）显示错误，类型“ Observable <{} []>中缺少属性'query'

2 个答案: