角度2：可观察不从服务返回对象（嵌套）

Question

我有一个返回用户对象的角度服务。用户对象有自己的属性和一组墙。服务向调用组件返回一个可观察的。在该服务中，我能够从http服务返回的json创建用户对象。但是，当我订阅组件中的服务时，返回的对象为null。我做错了什么？

// user.ts

import { wall } from './wall';

export class user {
    Id: number;
    EntryType: number;
    UserType: number;
    SubscriptionType: number;
    IsCoach: boolean;
    Username: string;
    Email: string;
    Name: string;
    Password: string;
    Created: string;
    MemberWalls: wall[];
}

//wall.ts
export class wall {
    Title: string;
    ViewItem_Id: number;
}

//authentication.service.ts

authenticate(authRequest: login): Observable<user> {
        let url: string = this.apiUrl + AppSettings.LOGIN_SERVICE;
        let headers = new Headers({
            'Content-Type': AppSettings.CONTENT_TYPE_HEADER, //'; charset=utf-8',
            'client-secret': AppSettings.CLIENT_SECRET,
            'client-id': AppSettings.CLIENT_ID
        });

        let options = new RequestOptions({ headers: headers });

        return this._http.post(url, authRequest, options) // 
            .map(data => {
                this.authenticated(data);
            })
            .catch(this.handleError);

    }

    private authenticated(res: Response) {
        let body = res.json();
        if (body.StatusCode === 200) {
            localStorage.setItem('auth_token', res.headers.get("access-token"));
            let user1: user = body.Data;
            //The user object is fine here. 
            //That means that the json and the user class structure match perfectly
            console.log(user1);
            return body.Data || {};
        }
        else {
            return {};
        }
    }

//login.component.ts

login() {
        this.errorMessage = '';
        this.currentUser = null;

            this._authService.authenticate(this.loginModel)
                .subscribe(user1 => this.currentUser = user1,
                error => this.handleError( error));

  //The user1 returned by the service is always null.
    }

Answer 1

接受冈特的回答：

user1=

Answer 2

映射post请求的结果时缺少return语句。

在es6和ts中：

• 当使用括号定义箭头函数时，返回语句是强制性的。
• 当定义一个没有括号的箭头函数时，es6自动生成一个返回语句，返回箭头符号后提供的表达式的值

前任：

let f = (data) => this.authenticated(data);;
// Or 
let f = (data) => { return this.authenticated(data); };