Home Web Front-end JS Tutorial Node.js+Koa framework realizes front-end and back-end interaction

Node.js+Koa framework realizes front-end and back-end interaction

Feb 28, 2017 pm 02:14 PM

Preface

For a front-end engineer, he not only needs to know the front-end content, but also needs to be proficient in back-end technology. Today I will use a case to describe how the front end interacts with the back end.

koa is built by the original team of Express and is committed to becoming a smaller, more expressive, and more robust web framework. Using koa to write web applications, by combining different generators, you can avoid repeated and cumbersome callback function nesting, and greatly improve the efficiency of error handling. koa does not bind any middleware in the kernel method. It only provides a lightweight and elegant function library that makes writing web applications easy.

Preparation

First of all, our server needs to deploy the Nodejs environment. Here I use Nodejs’ local server under windows to do it. Demo.

To deploy the NodeJS environment, please see: "Detailed Graphical Explanation of the Steps to Install Node.js on Windows Systems".

Friends who are not familiar with the Koa framework can refer to this article: Getting Started with the Koa Framework for Node.js and MySQL Operation Guide

The method is as follows

After the environment is deployed, we need to create a project directory and install the Koa framework and some dependent libraries through npm in the directory.

The picture below is the directory structure after I completed it.

Node.js+Koa framework realizes front-end and back-end interaction

cd to your project directory, and then execute npm koa directory, there will be a folder like node_modules, which stores some dependent libraries used.

Node.js+Koa framework realizes front-end and back-end interaction

Next we create an app.js file to set the route used when accessing the server. The code is as follows

var koa = require('koa');
var controller = require('koa-route');//需要通过npm来添加此依赖
var app = koa();

var service = require('./service/WebAppService.js');//引用WebAppService.js

/*设置路由*/
app.use(controller.get('/ajax/search',function*(){
 this.set('Cache-Control','no-cache');
 this.set('Access-Control-Allow-Origin','*');
 var querystring = require('querystring');
 var params = querystring.parse(this.req._parsedUrl.query);
 var key = params.key;
 var start = params.start;
 var end = params.end;
 this.body = yield service.get_search_data(key,start,end);
}));

app.listen(3001);
console.log('Koa server is started');
Copy after login

There is no koa-route dependency in the node_modules folder by default. You need to install it through npm koa-route

Then we need to create a WebAppService.js in the service directory file, used to request the interface, the code is as follows

var fs = require('fs');
exports.get_search_data = function(key,start,end){
 return function(cb){

  var http = require('http');
  var qs = require('querystring');
  var data = {
   key:key,
   start:start,
   end:end
  };

  /*请求MobAPI里的火车票查询接口*/
  var content = qs.stringify(data);
  var http_request = {
   hostname:'apicloud.mob.com',
   port:80,
   path:'/train/tickets/queryByStationToStation?' + content,
   method: 'GET'
  };

  var req = http.request(http_request,function(response){
   var body = '';
   response.setEncoding('utf-8');
   response.on('data',function(chunk){
    body += chunk;
   });
   response.on('end',function(){
    cb(null,body);
   });
  });

  req.end();
 }
}
Copy after login

This actually makes an interface transfer, we can not only request the local interface but also request The third-party interface prevents the browser from blocking requests when making cross-domain requests.

Next we start the service through the command, enter node app.js in the terminal

Node.js+Koa framework realizes front-end and back-end interaction

and then request the interface http://www.php in the browser. cn/:3001/ajax/search?key=520520test&start=Beijing&end=Shanghai

Node.js+Koa framework realizes front-end and back-end interaction

In this way, we have implemented the interface request and obtained the json data. Interested friends can Take a look at the following article. The following article will present the data obtained from the backend on the interface in a more intuitive way, and use the Vue.js framework to create a train ticket query system.


For more articles related to XNode.js+Koa framework realizing front-end and back-end interaction, please pay attention to the PHP Chinese website!



Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
2 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Repo: How To Revive Teammates
4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Hello Kitty Island Adventure: How To Get Giant Seeds
4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Replace String Characters in JavaScript Replace String Characters in JavaScript Mar 11, 2025 am 12:07 AM

Detailed explanation of JavaScript string replacement method and FAQ This article will explore two ways to replace string characters in JavaScript: internal JavaScript code and internal HTML for web pages. Replace string inside JavaScript code The most direct way is to use the replace() method: str = str.replace("find","replace"); This method replaces only the first match. To replace all matches, use a regular expression and add the global flag g: str = str.replace(/fi

Custom Google Search API Setup Tutorial Custom Google Search API Setup Tutorial Mar 04, 2025 am 01:06 AM

This tutorial shows you how to integrate a custom Google Search API into your blog or website, offering a more refined search experience than standard WordPress theme search functions. It's surprisingly easy! You'll be able to restrict searches to y

Build Your Own AJAX Web Applications Build Your Own AJAX Web Applications Mar 09, 2025 am 12:11 AM

So here you are, ready to learn all about this thing called AJAX. But, what exactly is it? The term AJAX refers to a loose grouping of technologies that are used to create dynamic, interactive web content. The term AJAX, originally coined by Jesse J

Example Colors JSON File Example Colors JSON File Mar 03, 2025 am 12:35 AM

This article series was rewritten in mid 2017 with up-to-date information and fresh examples. In this JSON example, we will look at how we can store simple values in a file using JSON format. Using the key-value pair notation, we can store any kind

10 jQuery Syntax Highlighters 10 jQuery Syntax Highlighters Mar 02, 2025 am 12:32 AM

Enhance Your Code Presentation: 10 Syntax Highlighters for Developers Sharing code snippets on your website or blog is a common practice for developers. Choosing the right syntax highlighter can significantly improve readability and visual appeal. T

8 Stunning jQuery Page Layout Plugins 8 Stunning jQuery Page Layout Plugins Mar 06, 2025 am 12:48 AM

Leverage jQuery for Effortless Web Page Layouts: 8 Essential Plugins jQuery simplifies web page layout significantly. This article highlights eight powerful jQuery plugins that streamline the process, particularly useful for manual website creation

10  JavaScript & jQuery MVC Tutorials 10 JavaScript & jQuery MVC Tutorials Mar 02, 2025 am 01:16 AM

This article presents a curated selection of over 10 tutorials on JavaScript and jQuery Model-View-Controller (MVC) frameworks, perfect for boosting your web development skills in the new year. These tutorials cover a range of topics, from foundatio

What is 'this' in JavaScript? What is 'this' in JavaScript? Mar 04, 2025 am 01:15 AM

Core points This in JavaScript usually refers to an object that "owns" the method, but it depends on how the function is called. When there is no current object, this refers to the global object. In a web browser, it is represented by window. When calling a function, this maintains the global object; but when calling an object constructor or any of its methods, this refers to an instance of the object. You can change the context of this using methods such as call(), apply(), and bind(). These methods call the function using the given this value and parameters. JavaScript is an excellent programming language. A few years ago, this sentence was

See all articles