Nodejs applet server construction

With the popularity of WeChat mini programs, more and more developers are beginning to try to develop their own mini program servers. In the past, developers needed to use Java, PHP and other languages ​​to build the server side, but now, using nodejs to build the server side of small programs has become a new trend, because nodejs is lightweight, highly scalable and compatible with JavaScript Language convenience and other advantages.

This article will introduce how to use nodejs to build a small program server, and provide some guidance and help for developers.

1. Installation and configuration nodejs

1. Installing nodejs

First, you need to install nodejs on your computer. You can visit https://nodejs.org/en/ to download the latest version of nodejs and install it later.

After the installation is complete, you can enter the following command in the terminal to check whether nodejs is successfully installed:

$ node -v

If a version number similar to v12.14.0 is displayed, it means that you have successfully installed nodejs.

2. Configuring npm

npm is a tool for nodejs package management. You can use it to easily manage the modules you need to use. When installing nodejs, npm is also installed by default. You can enter the following command in the terminal to check whether npm is installed successfully:

$ npm -v

If a version number similar to 6.13.4 is displayed, it means you have successfully installed npm.

2. Create the mini program server

1. Directory structure

Before you start building the mini program server, you first need to create a project directory and Install the required nodejs packages in it.

Execute the following command in the terminal to create and enter the project directory:

$ mkdir mini-app-server
$ cd mini-app-server

In the project directory, use npm to install the required packages:

$ npm install express body-parser request

Here we used Three packages:

• express: A nodejs package that facilitates the creation of web applications.
• body-parser: nodejs middleware, used to parse the body part of http requests.
• request: A simple module for sending http requests in nodejs.

After the installation is complete, your project directory should look like this:

.
├── node_modules
│   ├── body-parser
│   ├── express
│   └── request
└── index.js

2. Writing the server code

Next, after you Create an index.js file in the project directory and enter the following code:

const express = require('express')
const bodyParser = require('body-parser')
const request = require('request')

const app = express()
const PORT = 3000

app.use(bodyParser.json())

app.get('/', (req, res) => {
  res.send('Server is running!')
})

app.listen(PORT, () => {
  console.log(`Server is running on localhost:${PORT}`)
})

Here, a web application is created using express and listens on port 3000. In this application, we define a get request. When accessing '/', a string of 'Server is running!' will be returned.

3. Run the server

Next, you can run the server by executing the following command in the terminal:

$ node index.js

If everything is fine, you should see to output similar to "Server is running on localhost:3000".

Now, you have successfully created a simple applet server using nodejs!

3. Interact with mini programs

Next, let’s take a look at how to use nodejs to interact with mini programs.

First, we need to obtain the appid and appsecret of our own mini program through the WeChat mini program management background. Then, add the following content in the server code:

// 小程序设置
const APP_ID = 'your_app_id'
const APP_SECRET = 'your_app_secret'

// 获取access_token
app.get('/access_token', (req, res) => {
  const url = `https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=${APP_ID}&secret=${APP_SECRET}`
  request.get(url, (error, response, body) => {
    if (!error && response.statusCode === 200) {
      const { access_token } = JSON.parse(body)
      res.json({ access_token })
    } else {
      console.error(error)
      res.status(response.statusCode).send(body)
    }
  })
})

Here, we obtain the access_token by requesting the interface of the WeChat applet, and then return it to the applet. When the applet needs to use the access_token, it can obtain it simply by interacting with the server.

4. Writing Mini Program Code

In the mini program, we can use wx.request to initiate a request with the server to obtain access_token and other information.

The following is an example of obtaining access_token:

wx.request({
  url: 'http://localhost:3000/access_token',
  success: (res) => {
    const { access_token } = res.data
    console.log(access_token)
  },
  fail: (res) => {
    console.error(res)
  }
})

5. Summary

This article introduces how to use nodejs to build a mini program server and interact with the mini program The example shows the application scenario of nodejs. Using nodejs to build a small program server has the advantages of being easy to understand, lightweight and efficient, and is very suitable for beginners and small teams. At the same time, developers are also encouraged to try different technologies and improve their programming skills through practice.

The above is the detailed content of Nodejs applet server construction. For more information, please follow other related articles on the PHP Chinese website!