Question

我想知道使用Angular 2和AngularFire2处理类中动态属性的最佳实践是什么。

在我的Firebase数据库中，我有以下方案：

$company
- users
-- $user
--- public
--- chats
--- events
---- $event
----- id
----- timestamp
- events
-- $event
--- id
--- timestamp
--- joiners
---- $joiner
----- uid

我实施了一项用户服务：

// UserService
@Injectable()
export class UserService {
  constructor(private af: AngularFire, private dbService: DatabaseService) {}

  getUser(uid: string): Observable<User> {
    console.log('Retrieveing user for uid ', uid);

    let now: number = Date.now();

    return Observable.combineLatest(
      this.dbService.getNodeAsObjectObservable(true, `users/${uid}/public`),
      this.dbService.getNodeAsListObservable(true, `users/${uid}/events`, {
        query: {
          orderByChild: 'timestamp',
          startAt: now
        }
      })
    ).map(([info, joinedEvents]) => (new User({uid, info, joinedEvents})));
  }
}

数据库服务：

@Injectable()
    export class DatabaseService {
      public root: any;
      public queue: any;
      public company: any;

      constructor(private af: AngularFire) {
        console.log('DatabaseService constructor');
      }

      setCompany(company: string): void {
        this.company = company;
      }

      // Utilities
      getNodeAsListObservable(companyRelated: boolean, node: string, query?: any): FirebaseListObservable<any> {
        console.log('DatabaseService - getNodeAsListObservable: with args ',
          companyRelated, node, query
        );
        let ref: string;

        companyRelated ? ref = this.company : ref = this.root;

        if (query) {
          return this.af.database.list(`${ref}/${node}`, query);
        } else {
          return this.af.database.list(`${ref}/${node}`);
        }

      }
      getNodeAsObjectObservable(companyRelated: boolean, node: string): FirebaseObjectObservable<any> {
        let ref: any;

        companyRelated ? ref = this.company : ref = this.root;

        return this.af.database.object(`${ref}/${node}`);

      }
}

在我的家里：

user: Observable<User>;

  constructor(public navCtrl: NavController, private userService: UserService) {
    console.log('HomePage constructor');
  }

  ngOnInit(): void {
    // Retrieve current user
    this.user = this.userService.getUser('abizhdiuh738937bj');
  }

最后我的User类定义如下：

export interface IUser {
  uid: string;
  info: any;
  //joinedEvents?:
}

export class User implements IUser {
  uid: string;
  info: any;
  joinedEvents?: FirebaseListObservable<Event>;
  constructor(obj?: any) {
    if (obj.uid) this.uid = obj.uid;
    if (obj.info) this.info = obj.info;
    if (obj.joinedEvents) {
      for (let i = 0; i < obj.joinedEvents.length; i++) {
        // Q1: how to retrieve details of each event
      }
    }
  }
}

对于每个joinEvents，我想在视图中显示它之前检索它的详细信息。

所以我的问题是什么是解决这个问题的最佳方式？

我有几个想法：

调用返回FirebaseObservableList的getEvent（event_id）函数
在getUser（）（在UserService中）一次

this.dbService.getNodeAsListObservable（true，users/${uid}/events，{ 查询：{ orderByChild：＆＃39; timestamp＆＃39;， startAt：现在 } }）

完成后调用getEvent（event_id）函数。怎么做到这一点？
这个函数应该返回一个Observable？理想情况下，就像我为用户所做的那样，我想使用一个Event类（但可能是我错了，愿意这样......）

我很失落如何处理这种封装的复杂性。此外，我将不得不处理与每个用户所属的聊天非常相似的内容...希望你能提供帮助。感谢

如何使用Angular 2和AngularFire2

0 个答案: