angular - 注销时如何摆脱 "Error: permission_denied"？ (Angular-Firebase)

Question

嗨，我是 Angular 和 Firebase 的新手，对下一个问题感到困惑:
我有两个组成部分-
授权区域(父组件)和文件夹(子组件)。授权区域有一个注销按钮，文件夹可以访问来自 firebase 的 auth-data。问题是，当用户注销所有操作成功时，会出现一条错误消息，我正试图摆脱它。
父组件:authorized-zone

export class AuthorizedZoneComponent implements OnInit {
  
  constructor(public authService: AuthService) { }
  ngOnInit(): void {}

  //btn logout listener
  logout() { this.authService.logout(); }
}

   <app-folders></app-folders>
   <button id="logout"(click)="logout()">logout</button>`

子组件:文件夹

export interface Folder{
  id:string;
  name:string;
  key: string;
}

//This Component is to be used only by Authorized-zone!
export class FoldersComponent implements OnInit {

  private dbPath='/folders';//path to folders in realtime data base
  private folderArray: Array<Folder>=[];//Array for folders: each folder has id and name

  constructor(private router: Router, private route:ActivatedRoute, private db: AngularFireDatabase) { 
    
    this.db.list(this.dbPath).valueChanges().subscribe(data => {
      for( let i=0; i< data.length; i++){
        this.folderArray.push({id: data[i]["id"], name: data[i]["name"], key: data[i]["key"]});
      }
    })
  }

  ngOnInit(): void {}

  //returns array of folders
  getFolders(){ return this.folderArray;}

  //on folder click listerner
  onSelect(folder){}
}

<div (click)="onSelect(folder)" *ngFor="let folder of getFolders()> 
    <div class="folder" [id]="folder.id">{{folder.name}}</div> 
</div>

auth-service 使用户能够登录和注销

事件流似乎工作正常。
但是，当我按下注销按钮时，虽然功能有效，但我收到一条控制台错误消息:

ERROR Error: permission_denied at /folders: Client doesn't have permission to access the desired data...

我注意到如果我删除 <app-folders></app-folders>错误不准确。

我试过删除 <app-folders></app-folders>在authorized-zone.component 中注销之前:

//btn logout listener
  logout() {
    document.querySelector('app-folders').replaceWith("");
    this.authService.logout();
  }

它没有用，如果有人能够解释问题并推荐解决方案，我将非常感激

Answer 1

我找到了解决方案:在文件夹组件中使用 ngOnDestroy。

      private dbData;
    
      constructor(private router: Router, private route:ActivatedRoute, private db: AngularFireDatabase) { 
        
        this.dbData=this.db.list(this.dbPath).valueChanges()
        .subscribe(data => {//...
    
    
        })
      }
    
    
      //destroy firebaseData before logging out
      ngOnDestroy(){
        this.dbData.unsubscribe();
      }