Node.js请求主体为空

Question

I am having a hell of a time with this one. I don't know why my node.js response is empty. It comes back {} if I send it through the javascript here, or if I use the Advanced REST client. Here is my code:

client.js

unction ajaxPost(){

var req = new XMLHttpRequest();
var payload = {'Add Item':'Add Item',
                'name':document.getElementById('submitForm').elements[0].value,
                'reps':document.getElementById('submitForm').elements[1].value,
                'weight':document.getElementById('submitForm').elements[2].value,
                'date':document.getElementById('submitForm').elements[3].value,
                'lbs':document.getElementById('submitForm').elements[4].value
           }
payload['test'] = 'value!';
console.log('did this happen?');
console.log(payload['test']);
var url = '/edit';
req.open('POST', url, true);
req.setRequestHeader('Content-Type', 'application/json');
req.addEventListener('load',function(){
  if(req.status >= 200 && req.status < 400){
    var response = JSON.parse(req.responseText);
    console.log('you got a response!')

  } else {
    console.log("Error in network request: " + req.statusText);
  }});
console.log(JSON.stringify(payload));
req.send(JSON.stringify(payload));

event.preventDefault();

}

HTML

<form id = "submitForm">
    <input type="text" name="name" id="name" value='test'>Name<br>
    <input type="text" name="reps" id="reps" value='10'>Reps<br>
    <input type="text" name="weight" id="weight" value='100'>Weight<br>
    <input type="text" name="date" id="date" value='1/1/16'>Date<br>
    <input type="text" name="lbs" id="lbs" value='1'>Pounds<br>
    <input type="submit" onclick = 'ajaxPost()' value="Add Item">
</form>

server

var express = require('express');
var mysql = require('./dbcon.js');
var bodyParser = require('body-parser');

var app = express();
var handlebars = require('express-handlebars').create({defaultLayout:'main2'});

app.use(express.static(__dirname + '/public'));
app.use(bodyParser.urlencoded({ extended: false }));
app.engine('handlebars', handlebars.engine);
app.set('view engine', 'handlebars');
app.set('port', 3010);

app.post('/edit',function(req,res,next){
  //var context = {};
  console.log('you posted!');
  console.log(req.body);

In my console, I see that the req.body is {}.

I don't know what I am doing wrong. I have tried using httpbin and I can see that the javascript works fine, which means I am probably doing something wrong on the node side, but I cannot figure out what. If I instead use method="submit" on the form, then the post goes through just fine, but it's not what I want to do. What am I doing wrong?? Because advanced REST client also fails, I am guessing it is node?

Answer 1

You are sending json in the request, but you only have middleware setup to handle url encoded requests. Add this to your middleware and json requests should populate in the req.body.

app.use(bodyParser.json());

More info can be found at in the body parser documentation. Specifically you'll notice that the middleware you are using urlencoded states that it only parses urlencoded bodies (this is where Content-Type is used).