Express

install

Basic use

const express = require('express')
const app = express()
const port = 3000

app.get('/', (req, res) => res.send('Hello World!'))

app.listen(3000, () => console.log(`Example app listening on port 3000!`))

Basic routing

Router

• Request method
• Request path
• Request processing function

get:

// When the / is requested by the GET method, the corresponding processing function is executed
app.get('/', (req, res) => res.send('Hello World! GET'))

post:

app.post('/', (req, res) => res.send('Hello World! POST'))

GET the form GET data request body in Express

Express has a built-in API that you can use directly req.query To get

app.post('/sub',function(req, res){
    var comment = req.query
    comment.dateTime = time.format(new Date(), 'YY-MM-DD')
    comments.push(comment)
    // redirect
    res.redirect('/')
})

Get the form post data request body in Express

body-parser

• Official body parser document

install

npm install body-parser --save

to configure

var express = require('express')
var bodyParser = require('body-parser')

var app = express()

// Configure body parser
// As long as this configuration is added, there will be an additional attribute on the req request object: body
// Then you can directly pass req.body To get the data of the form POST request
app.use(bodyParser.urlencoded({ extended: false }))

// parse application/json
app.use(bodyParser.json())

use

app.post('/post',function(req, res){
    var comment = req.body
    comment.dateTime = time.format(new Date(), 'YY-MM-DD')
    comments.push(comment)
    // redirect
    res.redirect('/')
})

Static service

//1. The path must be a file under / public/xxx before access under the public directory
app.use('/public/', express.static('./public/'))

//2. Release the file under public, and access directly without adding public / xxx
app.use(express.static('./public/'))

//3. If you use / pub / to alias / public /, you need to access the file under public through / pub/xxx
app.use('/pub/',express.static('public'))
app.use('/pub/aa/',express.static('public ')) / / aliases can also be created in this way

Configuring the use of art template template engine in Express

• Art template official document
• Art template express configuration document

install

npm install --save art-template
npm install --save express-art-template

to configure

// Although there is no need to record art template outside, it must also be installed
// The reason is that express art template relies on art template
	app.engine('art', require('express-art-template'));

use

app.get('/', function(req, res){
    // express defaults to the views directory index.html
   	res.render('index.html', {
        title: 'This is a title'
    })
    // 	res.render('404.html')
	//  res.render('admin/404.html ') / / access 404.html under admin under views
})

If you want to modify the default views rendering store directory, you can:

// Modify views, modify the default path of render function
// app.set ('views', default path to render function)
	app.set('views', '/show')

redirect

//Jump to the specified URL
res.redirect("https://mp.csdn.net/");
//Jump to home
res.redirect("/");