Angular 2 Observable

Question

我试图从其余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。

我想在一个组件中有2个变量，观察服务中设置的2个变量。我正在经历的是1个观察者被定义并包含结果，另一个观察者因为某种原因在服务中“未定义”而没有定义。

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

任何洞察力赞赏...

这里是服务中的代码。

@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); 

});