如何在Angular 2中触发ajax请求？

Question

我在Angular 2中定义了这样的服务:

import { Inject } from 'angular2/angular2';
import { Http ,Headers , HTTP_PROVIDERS } from 'angular2/http';

export interface CourseInterface {
    courseId: number,
    coursePrice: number,
    authorName: string
}

export class CourseDetailsService {
    http: Http;
    constructor(@Inject(Http) Http) {
        console.log(Http)
        this.http = Http;
    }

    load() {
        console.log("came here in service")
        var headers = new Headers();
        headers.append('Authorization', <my username password>);

        this.http.get('https://some.api',{
            headers : headers
        }).map(res => console.log("Response came!!!"))

        console.log("done . . .")
    }
}

在另一个组件中,我使用这样的服务:

import {CourseInterface, CourseDetailsService} from '../services/course';

@Component({
    selector: 'dashboard',
    viewBindings: [CourseDetailsService]
})
@View({
    template: `
        <h1>Dashboard page laoded</h1>
  `
})
export class Dashboard {
    constructor(service: CourseDetailsService) {
        service.load();
    }
}

在运行应用程序时,我可以看到我的Dashboard组件显示在屏幕上.但是,从那里CourseDetailsService,没有http电话被解雇.

但在控制台中,我能够看到以下内容:

came here in service
done . . . . 

但是在我的chrome networks标签中,我无法看到向指定网址发出的任何请求.我在哪里弄错了？

我正在使用Angular 2 Alpha 47

Answer 1

基本上触发请求的部分本身就是它subscribe,所以为了使它工作,你必须添加它.

// Service
load() {
    var headers = new Headers();
    headers.append('Authorization', <my username password>);

    return this.http.get('https://some.api',{
        headers : headers
    }).map(res => console.log("Response came!!!"))
}

// Component
// 'subscribe' triggers the request!
service.load().subscribe((result) => /* do something with result */);