Can't get POST data using NodeJS/ExpressJS and Postman - node.js

Question

This is the code of my server :
var express = require('express');
var bodyParser = require("body-parser");
var app = express();
app.use(bodyParser.json());
app.post("/", function(req, res) {
res.send(req.body);
});
app.listen(3000, function () {
console.log('Example app listening on port 3000!');
});
From Postman, I launch a POST request to http://localhost:3000/ and in Body/form-data I have a key "foo" and value "bar".
However I keep getting an empty object in the response. The req.body property is always empty.
Did I miss something?

Answer 1

Add the encoding of the request. Here is an example
..
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));
..
Then select x-www-form-urlencoded in Postman or set Content-Type to application/json and select raw
Edit for use of raw
Raw
{
"foo": "bar"
}
Headers
Content-Type: application/json
EDIT #2 Answering questions from chat:
why it can't work with form-data?
You sure can, just look at this answer How to handle FormData from express 4
What is the difference between using x-www-form-urlencoded and raw
differences in application/json and application/x-www-form-urlencoded

Answer 2

let express = require('express');
let app = express();
// For POST-Support
let bodyParser = require('body-parser');
let multer = require('multer');
let upload = multer();
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));
app.post('/api/sayHello', upload.array(), (request, response) => {
let a = request.body.a;
let b = request.body.b;
let c = parseInt(a) + parseInt(b);
response.send('Result : '+c);
console.log('Result : '+c);
});
app.listen(3000);
Sample JSON and result of the JSON:
Set Content-typeL application/JSON:

Answer 3

I encountered this problem while using routers. Only GET was working, POST, PATCH and delete was reflecting "undefined" for req.body. After using the body-parser in the router files, I was able to get all the HTTP methods working...
Here is how I did it:
...
const bodyParser = require('body-parser')
...
router.use(bodyParser.json());
router.use(bodyParser.urlencoded({ extended: true }));
...
...
// for post
router.post('/users', async (req, res) => {
const user = await new User(req.body) // here is where I was getting req.body as undefined before using body-parser
user.save().then(() => {
res.status(201).send(user)
}).catch((error) => {
res.status(400).send(error)
})
})
For PATCH and DELETE as well, this trick suggested by user568109 worked.

Answer 4

On more point I want to add is if you created your project through Express.js generator
in your app.js it also generates bellow code
app.use(express.json());
if you put your body-parser above this code the req.body will return null or undefined
you should put it bellow the above code see bellow for correct placement
app.use(express.json());
app.use(bodyParser.urlencoded({extended:true}));
app.use(bodyParser.json());

Answer 5

I experienced the same issue. I tried all that had been suggested here. I decided to console log the value of the request object. It's a huge object. Inside this object I saw this query object carrying my post data:
query: {
title: 'API',
content: 'API stands for Application Programming Interface.'
}
So it turns out that request.query, and not request.body, contains the values I send along with my post request from Postman.