req.body.data 在 nodejs 中未定义

Question

My client side

$.post("http://localhost:3000/scrape",
      {
      data: 'something'
      },
      function(data, status){
      console.log(data);
      });

What I do in node.js

var express = require('express');

var app = express();

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

app.use(bodyParser.json());

app.post('/scrape', function (req, res) {

    console.log(req.body.data)

});

But I got undefined in console.log(req.body.data), any idea why?

Answer 1

Your data must be of json format. since you are using bodyParser.json() .

Try setting the http header, Content-type as application/json in your $.post call and send a valid json structure as data

  $.ajax({
    url: "scrape", 
    type: "POST",
    data: JSON.stringify({ someData : "someData}),
    contentType:"application/json; charset=utf-8",
    dataType:"json",
    success: function(data){
          console.log(data)
    },
    error: function(){
          console.log('error in sending request')
    }
})

Answer 2

console.log(req.body.data)

returns undefined because the data is in req.body you should console.log(req.body) and add app.use(bodyParser.urlencoded({extended: false})); so that data not in json format can also be parsed.

if you want req.body.data have data then make request like

$.post("http://localhost:3000/scrape",
      {
      data: {data: 'something'}
      },
      function(data, status){
      console.log(data);
      });

also your request is not sending any response you need to do something like

app.post('/scrape', function (req, res) {

    console.log(req.body.data)
    res.status(200).json({data: reqr.body.data});

});

hope it helps :)