Angular 2 Observable

Question

我正在尝试从休息数据服务调用中设置2个变量，这会在元素“_embedded”和“page”中返回JSON文档中的结果。

我试图在一个组件中有2个变量，观察服务中设置的2个变量。我所经历的是1个观察者被定义并包含结果而另一个没有，因为它在服务中由于某种原因而被“未定义”。

错误是当我尝试执行此语句时_pageObservier未定义this._pageObserver.next（this._page）;

感谢任何见解......

以下是服务中的代码。

@Injectable()
export class ProductService {
  products$: Observable<Product[]>;
  pager$: Observable<{}>;
  private _baseUrl: string;
  private _pageObserver: Observer<{}>;
  private _productObserver: Observer<Product[]>;
  private _page:{};
  private _dataStore: { products: Product[]  };

  constructor(private _http: Http) {
    this._baseUrl  = 'http://localhost:8000/products';
    this.products$ = new Observable(observer => this._productObserver = observer).share();
    this.pager$ = new Observable(observer => this._pageObserver = observer).share();
    this._dataStore = { products: [] };
    this._page = {};
  }

  load() {
    //this._http.get(`${this._baseUrl}/product`).map(response => response.json()).subscribe(data => {
    this._http.get(`http://localhost:8000/products`).map(response => response.json()).subscribe(data => {
      this._dataStore.products = data['_embedded'].products;
      this._productObserver.next(this._dataStore.products);
      this._page = data['page'];
      this._pageObserver.next(this._page); <=== THIS IS NOT DEFINED
    }, error => console.log('Could not load products.'));
  }

Answer 1

this._page = {};

this.pager$ = new Observable(observer => {
   this._pageObserver = observer).share();
   this._pageObserver.next(this._page); 

 });