Angular 2 Observable

Question

我試圖從其餘數據服務調用中設置2個變量，這會在元素「_embedded」和「page」中返回JSON文檔中的結果。

我想在一個組件中有2個變量，觀察服務中設置的2個變量。我正在經歷的是1個觀察者被定義幷包含結果，另一個觀察者因爲某種原因在服務中「未定義」而沒有定義。

錯誤是，_pageObservier未定義，當我嘗試執行此語句this._pageObserver.next（this._page）;

任何洞察力讚賞...

這裏是服務中的代碼。

@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); 

});