Angular 2從http獲取請求的對象獲取請求

Question

我已經開始學習angular 2.我嘗試通過http get request獲取一些數據，然後我想用這些數據創建對象，以便稍後可以使用模板顯示它們。如果我用錯誤的方式思考，你可以告訴我。

我有我的模型AnalyticsData：

export class AnalyticsData { 
    pagePath: string; 
    pageViews: number; 
    uniquePageViews: number; 
    avgTimeOnPage: number; 
    entrances: number; 
    bounceRate: number; 

    constructor(object?: any) { 
     this.pagePath = object && object.pagePath || null; 
     this.pageViews = object && object.pageViews || null; 
     this.uniquePageViews = object && object.uniquePageViews || null; 
     this.avgTimeOnPage = object && object.avgTimeOnPage || null; 
     this.entrances = object && object.entrances || null; 
     this.bounceRate = object && object.bounceRate || null; 
    } 

} 

我的DataService：

export class DataService { 

    private dataUrl: string = 'http://example.com/app/analyticsdata'; 
    constructor(private http: Http) { } 

    getData() { 
     return this.http.get(this.dataUrl) 
      .map((response: Response) => response.json()); 
    } 

} 

我AnalyticsComponent：

export class AnalyticsComponent implements OnInit { 

    myData: Array<AnalyticsData>; 

    constructor(private services: DataService) { } 

    ngOnInit(): void { 
     this.getData(); 
    } 

    getData() { 
     this.services.getData() 
      .subscribe(
      function (response) { 
       response.forEach((element: AnalyticsData, index: number) => { 
        this.myData.push(
         new AnalyticsData({ 
          pagePath: element['ga:pagePath'], 
          pageViews: element.pageViews, 
          uniquePageViews: element.uniquePageViews, 
          avgTimeOnPage: element.avgTimeOnPage, 
          entrances: element.entrances, 
          bounceRate: element.bounceRate 
         }) 
        ); 
       }); 
      }, 
      function (error) { console.log("Error happened" + error) }, 
      function() { 
       console.log("the subscription is completed"); 
      } 
      ); 

    } 

} 

與上述錯誤是：EXCEPTION: Cannot read property 'push' of undefined。我不明白爲什麼會發生這種情況，因爲我已經在課程頂部分配了變量myData。

Answer 1

還可以使用arrowFunction如下所示()=>如，

getData() { 
     this.services.getData() 
      .subscribe(
      (response) => {          //<<<<===here 
       response.forEach((element: AnalyticsData, index: number) => { 
        this.myData.push(
         new AnalyticsData({ 
          pagePath: element['ga:pagePath'], 
          pageViews: element.pageViews, 
          uniquePageViews: element.uniquePageViews, 
          avgTimeOnPage: element.avgTimeOnPage, 
          entrances: element.entrances, 
          bounceRate: element.bounceRate 
         }) 
        ); 
       }); 
      }, 
      (error) => { console.log("Error happened" + error) }, //<<<===here 
      () => {            //<<<===here 
       console.log("the subscription is completed"); 
      } 
      ); 

    }