How to use Angular to implement data request function

This time I will show you how to use Angular to implement the data request function. What are the precautions for implementing the data request function in Angular? The following is a practical case, let's take a look.

When using Angular to request data, you need to introduce the Http

Module module. If you use the jsonp mode, you need to introduce the JsonpModule module

import { HttpModule, JsonpModule } from '@angular/http'

and then in the current module Register within the imports

imports: [
 HttpModule,
 JsonpModule
],

After registration, you can introduce the corresponding method in the component file to make data requests

import { Http, Jsonp } from '@angular/http'

Then in the

constructor of the current component After injecting it, you can use it

constructor(private http: Http, private jsonp: Jsonp) { }

Use as follows, a simple get request

// 进行注入，拿到相对应的方法
constructor(private http: Http, private jsonp: Jsonp) { }
public list: any = []
// 请求数据
getData() {
 let url = 'http://www.phonegap100.com/appapi.php?a=getPortalList&catid=20&page=1'
 let _this = this
 this.http.get(url).subscribe((data) => {
  _this.list = JSON.parse(data['_body'])['result']
  console.log(_this.list)
 })
}

Rendering in the frontend

<button (click)="getData()">get 请求数据</button>
<ul>
 <li *ngFor="let item of list">
  {{item.title}}
 </li>
</ul>

JSONP request Data

Pay attention to the difference from the get request, use the following

// 请求数据
jsonpData() {
 let url = 'http://www.phonegap100.com/appapi.php?a=getPortalList&catid=20&page=1&callback=JSONP_CALLBACK'
 let _this = this
 this.jsonp.get(url).subscribe((data) => {
  _this.list = data['_body']['result']
  console.log(_this.list)
 })
}

// 渲染
<button (click)="jsonpData()">jsonp 请求数据</button>
<ul>
 <li *ngFor="let item of list">
  {{item.title}}
 </li>
</ul>

Differences

The specified ## must be added at the end of the requested url parameter #Callback function

Name&callback=JSONP_CALLBACKThe request method changes to this.jsonp.get(url)

The data format obtained after the request is not uniform and needs to be adjusted by yourself

POST requestThe request method is slightly different from that of GET. First, you need to introduce the request header {Headers}

import { Http, Jsonp, Headers } from '@angular/http'

and then To define the request headers, you need to instantiate Headers first

private headers = new Headers({'Content-Type': 'application/json'})

Finally bring Headers when submitting data

postData() {
 let url = 'http://localhost:8080/login'
 let data = {
  "username": "zhangsan",
  "password": "123"
 }
 this.http.post(
  url,
  data,
  {headers: this.headers}
 ).subscribe((data) => {
  console.log(data)
 })
}

I believe you have mastered the method after reading the case in this article, and there will be more exciting things Please pay attention to other related articles on php Chinese website!

Recommended reading:

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