在Angular 2中映射http响应时获取[object Object] [英] Getting [object Object] while mapping http response in Angular 2

问题描述

我在 angular 2 中使用 Observable 地图时得到一个 [object Object].

I am getting an [object Object] while using Observable map in angular 2.

这是来自 API 服务的响应对象.

Here is the response object from the API service.

{
  "isSuccess": true,
  "message": "Connection Successfull",
  "data": [
    {
      "marketId": 1,
      "city": "san",
      "cityF": "san",
      "name": null,
      "nameF": "hello",
      "sortOrder": 1,
      "isActive": true
    },
    {
      "marketId": 2,
      "city": "san",
      "cityF": "san",
      "name": null,
      "nameF": "hello",
      "sortOrder": 1,
      "isActive": true
    },
    {
      "marketId": 3,
      "city": "san",
      "cityF": "san",
      "name": null,
      "nameF": "hello",
      "sortOrder": 1,
      "isActive": true
    },
    {
      "marketId": 4,
      "city": "san",
      "cityF": "san",
      "name": null,
      "nameF": "hello",
      "sortOrder": 1,
      "isActive": true
    }
  ],
  "exceptionErrorMessage": null,
  "errorCode": 0,
  "successMessage": null
}

这是我创建的用于映射响应的模型.

Here is the model I have created to map with the response.

export class MarketViewModel 
{
public isSuccess: boolean;
public message : string;
public successMessage : string;
public exceptionErrorMessage : string;
public errorCode: number;
public data: MarketListObject[];

}
export class MarketListObject 
{
    public marketId : number;
    public city: string;
    public cityF : string;
    public name : string;
    public nameF : string;
    public sortOrder : number;
    public isActive : boolean; 
}

调用http并映射响应的服务类.

Service class to call the http and map the response.

import { Headers, RequestOptions } from '@angular/http';
import { Router, ActivatedRoute, Params } from '@angular/router';
import { MarketViewModel} from "../ViewModel/Market.ViewModel";
import { Injectable }     from '@angular/core';
import { Http, Response } from '@angular/http';
import {Observable} from 'rxjs/Rx';
import 'rxjs/add/operator/map';
import 'rxjs/add/operator/catch';

@Injectable()
export class DashBoardService {
    private MarketUrl = "DashBoard/GetMarketList";
    private ResponseData: any;
    constructor(private http: Http, private router: Router, private  marketModel : MarketViewModel) {}

    public GetMarketListCall() :Observable<MarketViewModel> {
         return this.http.get(this.MarketUrl).map(this.extractData)
                    .catch(this.handleError);
    } 
private extractData(res: Response) {
    let body = res.json();
        console.log("Body Data = "+body.data);
    return body.data || { };
  }

这是调用 Service.ts 的 Component.ts

Here is the Component.ts which is calling Service.ts

import { Component } from '@angular/core';
import { MarketViewModel} from "../ViewModel/Market.ViewModel";
import { DashBoardService} from "../Service/DashBoard.Service";
import { Observable } from 'rxjs/Observable';

 @Component({
     selector: 'Market-app',
    templateUrl: 'DashBoard/MarketListView',
    providers: [DashBoardService, MarketViewModel]
 })

export class MarketComponent {
  constructor(private DashBoardservice: DashBoardService, private  marketModel : MarketViewModel) {
   }

ngOnInit() {
        this.DashBoardservice.GetMarketListCall().subscribe(
                               data => {this.marketModel = data;
                                    console.log("this"+this.marketModel); }, 
                                err => {console.log(err);});
}
}

当我看到控制台时，我收到了 [object Object] 响应.我想不通的错误在哪里

When I see to the console I am getting [object Object] response. Where is the mistake I am not able to figure it out

推荐答案

你必须改变你的 DashBoardService 如下，因为你必须返回 MarketListObject 数组作为可观察的而不是MarketViewModel :

You have to change your DashBoardService as below as you are have to return MarketListObject array as observable not MarketViewModel :

@Injectable()
export class DashBoardService {
  private MarketUrl = "DashBoard/GetMarketList";
  private ResponseData: any;

  constructor(private http: Http, private router: Router, private  marketModel : MarketViewModel) {}

  public GetMarketListCall() :Observable<MarketListObject[]> {
     return this.http.get(this.MarketUrl).map(this.extractData)
                .catch(this.handleError);
  } 

  private extractData(res: Response) {
    let body = res.json();
    console.log("Body Data = "+body.data);
    return body.data || [];
  }
}

此外，无需将 MarketViewModel 作为供应商传递给 MarketComponent，因此从 MarketComponent 供应商列表中删除 MarketViewModel并更改您的组件如下.

Also there is no need to pass MarketViewModel as providers inside MarketComponent so remove MarketViewModel from MarketComponent providers list and change your component as below .

import { Component } from '@angular/core';
import { DashBoardService} from "../Service/DashBoard.Service";
import { Observable } from 'rxjs/Observable';

@Component({
  selector: 'Market-app',
  templateUrl: 'DashBoard/MarketListView',
  providers: [DashBoardService]
})
export class MarketComponent {

  public marketList: any[];

  constructor(private dashBoardservice: DashBoardService) {
  }

  ngOnInit() {
    this.dashBoardservice.GetMarketListCall().subscribe((data) => { 
      this.marketList = data;
      console.log("this" + this.marketList);
    },(err) => {
      console.log(err);
    });
  }
}

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