Question

在我的角度应用中，我创建了一个Observable来为多个组件提供数据更新。当用户单击按钮时，Observable的所有订阅者都应使用不同的数据集进行更新。以下是代码。

import { Observable } from 'rxjs/Observable';
import { Subscriber } from 'rxjs/Subscriber';

export class MyService {
private data: number[] = [5,6,7,8];

/// The observable given to outside
private observable: Observable<number[]>;

/// Subscribers of the observable which is given to outside
private subscribers: Map<number, Subscriber<number[]>>;
private nextSubscriberId = 0;

constructor() {
    this.subscribers = new Map();
    this.observable = new Observable(subscriber => {
        const id = ++this.nextSubscriberId;
        this.subscribers.set(id, subscriber);

        subscriber.next(data);

        return () => { this.subscribers.delete(id); };
    });

}

}

在按钮点击事件中，我执行以下操作

data = [1,2,3,4]; 
this.subscribers.forEach((subscriber, key) => {
    subscriber.next(data);
    });

我的问题是，这是管理Observable订户的最佳方式吗？是否有其他方式来处理订阅者而不是由我们自己管理？

Answer 1

你基本上想要创建自己的Subject实现。试试这个：

import { Observable } from 'rxjs/Observable';
import { Subject } from 'rxjs/Subject';

export class MyService {
  private source = new Subject<number[]>();
  data$ = this.source.asObservable();

  constructor() {}

  next(data: number[]) {
    this.source.next(data);
  }
}

producer.component.ts

class ProducerComponent {
  constructor(private myService: MyService) {}

  ngOnInit() {
    this.myService.next([1,2,3]);
  }
}

consumer.component.ts

class ConsumerComponent {
  constructor(private myService: MyService) {}

  ngOnInit() {
    this.myService.data$.subscribe(data => // ...)
  }
}

如果您想在服务中拥有初始值，请替换：

private source = new Subject<number[]>();

与

private source = new BehaviorSubject<number[]>([1,2,3,4]);，其中[1,2,3,4]是初始值。

如何更新Angular Observable的订阅者

1 个答案: