Angular2笔记7-http

这一部分在前端伪造了一个http服务, 然后按RestFul风格, 把增删改查重写了

前端http服务

import { InMemoryBackendService, SEED_DATA } from 'angular2-in-memory-web-api';
import { InMemoryDataService }               from './in-memory-data.service';
//给AppComponent配置一个临时的http服务测试
bootstrap(AppComponent, [
    appRouterProviders,
    HTTP_PROVIDERS,
    { provide: XHRBackend, useClass: InMemoryBackendService }, // in-mem server
    { provide: SEED_DATA, useClass: InMemoryDataService }      // in-mem server data
]);

export class InMemoryDataService {
  //createDb什么的是http客户端提供的方法
  createDb() {
    let heroes = [

##　*.server.ts

import { Injectable }    from '@angular/core';
import { Headers, Http } from '@angular/http';
import 'rxjs/add/operator/toPromise';
import { Hero } from './hero';
@Injectable()
export class HeroService {
  private heroesUrl = 'app/heroes';  //URL前缀
  constructor(private http: Http) { }
  getHeroes(): Promise<Hero[]> {
    return this.http.get(this.heroesUrl)
               .toPromise()//toPromise是第三方提供的 'rxjs/add/operator/toPromise';
               .then(response => response.json().data)
               .catch(this.handleError);
  }
  getHero(id: number) {
    return this.getHeroes()
               .then(heroes => heroes.find(hero => hero.id === id));
  }
  //自己封装一个saveOrUpdate
  save(hero: Hero): Promise<Hero>  {
    if (hero.id) {
      return this.put(hero);
    }
    return this.post(hero);
  }
  delete(hero: Hero) {
    let headers = new Headers();
    headers.append('Content-Type', 'application/json');//指定返回类型
    let url = `${this.heroesUrl}/${hero.id}`;
    return this.http
               .delete(url, {headers: headers})
               .toPromise()
               .catch(this.handleError);
  }
  // Add new Hero
  private post(hero: Hero): Promise<Hero> {
    let headers = new Headers({
      'Content-Type': 'application/json'});
    return this.http
               .post(this.heroesUrl, JSON.stringify(hero), {headers: headers})
               .toPromise()
               .then(res => res.json().data)
               .catch(this.handleError);
  }
  // Update existing Hero
  private put(hero: Hero) {
    let headers = new Headers();
    headers.append('Content-Type', 'application/json');
    let url = `${this.heroesUrl}/${hero.id}`;
    return this.http
               .put(url, JSON.stringify(hero), {headers: headers})
               .toPromise()
               .then(() => hero)
               .catch(this.handleError);
  }
  //错误处理
  private handleError(error: any) {
    console.error('An error occurred', error);
    return Promise.reject(error.message || error);
  }
}