Express Middleware

Types

I list some middleware that frontend developer normally use to get data.There are several type of HTTP Request as following:

  • query
  • form
  • path
  • cookie
  • header

Install and Declaration

npm install express
npm install cookie-parser
npm install body-parser
const express = require('express')
const app = express()
const cookieParser = require('cookie-parser')

app.use(cookieParser())

// 请求体参数是: name=tom&pwd=123
app.use(express.urlencoded({extended: true}))  

// 请求体参数是json结构: {name: tom, pwd: 123}
app.use(express.json()) 

//404 not find notice it is at the end
app.use((req,res,next)=>{
    res.status(404).send('404')
})

Read Data

GET

// query data
app.get('/',(req,res)=>{
    res.json(req.query)
})

// path params 
app.get('/abc:id',(req,res)=>{
    res.json(req.params)
})

POST

// form param => axios.post('/',{data:{'..':'..'}})
app.post('/',(req,res)=>{
    res.json(req.body)
})

BUT reading axios.post params using following 

app.post('/',(req,res)=>{
    res.json(req.query)
})
app.put('/',(req,res)=>{
    res.json(req.cookies)
})
app.patch('/',(req,res)=>{
    res.send(req.get('Content-Type'))
})