request.body is empty in node.js, express and body parser

Question

I am trying to "post" a request to my node server.

Following is the xhttp request.

let parcel = {
  userId: userId, //string
  unitid: unitid, //string
  selections: selections //array
};

 //Call to the Server
 var oReq = new XMLHttpRequest();
 oReq.addEventListener("load", transferComplete);

 oReq.open("GET", "http://node.server.com/interaction", true);
 //oReq.setRequestHeader('Content-Type', 'application/json');
 oReq.send(parcel);

 function transferComplete(evt) {
     console.log(this.responseText);
 }

Here is the server code

const express = require('express');
const bodyParser = require('body-parser');
var cors = require('cors');

let app = express();

app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));

const interaction = require('./routes/interaction');

app.use('/interaction', interaction);

app.use(function(req, res, next) {
  var err = new Error('Not Found');
  err.status = 404;
  next(err);
});

app.set("port", process.env.PORT || 5000);

var server = app.listen(app.get('port'), () => {
  console.log("server is started");
});

And the interaction router

var express = require('express');
var router = express.Router();

router.get('/', function(req, res, next) {
  console.log(req.body)
  res.send(req.body);
});

module.exports = router;

The request receives a response but the console.log(req.body) returns an empty object. I have even checked the "req" object. The body node in that object is empty too. Where am i going wrong. Where can i receive my parcel object in server?

Answer 1

You are not sending any body in the client side so it is not surprising that you are not receiving it on the server.

You're making a GET request that doesn't have a body by definition.

Try using curl to make a request with a body and see if you get in on the server - that way you should eliminate the possibility that it's a problem with Express or body-parser. Make sure you use a correct content-type.

If you want to send a body then:

1. use an HTTP method that supports it in your route handler (like POST)
2. use the same HTTP method on the client side
3. actually send something as a body correctly

If you have trouble using the XMLHttpRequest directly (which has a terrible API) then use something like jQuery, browser-request, SuperAgent, Axios, Got, Request, Reqwest etc.:

• http://api.jquery.com/jquery.ajax/
• https://www.npmjs.com/package/browser-request
• http://visionmedia.github.io/superagent/
• https://github.com/mzabriskie/axios
• https://github.com/sindresorhus/got
• https://github.com/request/request
• https://github.com/ded/reqwest

Also to debug the data that was actually sent in the request, see the Network tab in your browser's developer tools and to have a really good insight about what's going on, use netcat:

$ nc -lp 3333

It listens on port 3333 (in this case) and will print the entire request with all headers and body. For example accessing http://localhost:3333/xxx in the browser might print:

GET /xxx HTTP/1.1
Host: localhost:3333
Connection: keep-alive
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/59.0.3071.109 Chrome/59.0.3071.109 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8
Accept-Encoding: gzip, deflate, br
Accept-Language: en-US,en;q=0.8,pl;q=0.6
Cookie: io=HQz0J7NwYj76pKf_AAAD

Note that it will not return a response by itself and it will work for a single request only so you'll need to restart your netcat command to test it again.