Postman send strange response for raw JSON post (node js) - node.js

I'm trying to do a POST request using raw json.
In the Body tab I have "raw" selected with this body:
{
"name": "book"
}
On the Node js side I'm doing res.send(JSON.stringify(req.body))
router.post('/', (req, res, next) => {
res.send(JSON.stringify(req.body));
}
And in POSTMAN response I receive:
{"{\n\"name\": \"book\"\n}":""}
When expected something like
{"name":"book"}
Have no idea - where could be a reason for it?

You'll need to use the Express JSON body parser, install using
npm install body-parser;
Then:
const bodyParser = require('body-parser');
app.use(bodyParser.json());
Once you do this, the JSON data will be parsed correctly and when you send it back it will render correctly.
Also make sure you have your Content-Type header set to "application/json" in your Postman request (go to "Headers" and add a new "Content-Type" header with value "application/json")
Here's a simple express app that will echo any JSON POST:
const express = require("express");
const port = 3000;
const app = express();
const bodyParser = require('body-parser')
app.use(bodyParser.json());
app.post('/', (req, res, next) => {
console.log("Body: ", req.body);
res.send(JSON.stringify(req.body));
})
app.listen(port);
console.log(`Serving at http://localhost:${port}`);

If you're on Express v4.16.0 onwards, try to add this line before app.listen():
app.use(express.json());
This is a built-in middleware function in Express. It parses incoming requests with JSON payloads and is based on body-parser.

Looks to me like its not a fault of Postman, but your NodeJS service is applying JSON.stringify twice?
Can you log the response type from the server to console to check whether its already json content or not?

try with hard coded json response and then with dynamic variable
res.json({"name":"book"});

Related

req.body returns an empty object eventhough data is passed through form

this is my index.js code and it returns an empty object even though data is passed on from the front-end
const express = require("express");
const cors = require("cors");
const app = express();
app.use(cors());
app.use(express.json());
app.post("/api/register", (req, res) => {
console.log(req.body);
res.json({ status: "ok" });
});
app.listen(8000, () => {
console.log("listening on port 8000 . . . ");
});
For the specific case you're talking about, you usually need oa body parser to be able to access the form input fields. The minimum example that I advice you to build above it is the following:
// parse requests of content-type - application/json
app.use(express.json());
// parse requests of content-type - application/x-www-form-urlencoded
app.use(express.urlencoded({ extended: true }));
Some other hints
Make sure that the request is being submitted with the header Content-Type: application/x-www-form-urlencoded or Content-Type: application/json
Check if there any CORS problems
Here's More reference for you
The main reason this does not work is
some how the data passed in body is in text format while req.body is
expecting json data
make sure to double chek the 'Content-Type':'application/json' is set on the request headers
if you are using multipart/form-data or require a file upload from frontend you will need a multer as middleware for your post/patch requests, otherwise you can set your frontend to send application/json
[edit]
this line looks missing from your index.js
app.use(express.urlencoded({extended: true}))

How to use body request express

I want to access to the body to my request but he is empty. I use a body-Parser but I don't know why I haven't data in my body.
import express from 'express';
import * as bodyParser from 'body-parser';
const app = express();
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));
const port = 3000;
app.post('/', (request, response) => {
response.send(request.body);
});
app.listen(port, () => {
console.log(`you can run the server on http://localhost:${ port }`);
});
result:
{}
for my request I use postman
so I don't understand, I read other topic or forums and he this is the same code.
body-parser uses the Content-Type header to determine how the body will be parsed. My immediate suspicion (because I've done the same thing before) is that you may not be passing the Content-Type header - for example, if you are trying to use JSON, you need to be sending Content-Type: application/json on your POST request.

How to consume JSON in Express JS?

In very new to express js. I just wrote a simple program to send JSON request through postman and get the response.
Why I can't get any response? it always says could not get any response. I go through several tutorials and could not figure out what exact missing here?. Here is my code.
const express = require('express');
const app = express();
app.use(express.json);
app.post('/', (req, res) => {
console.log(req.body);
res.send(req.body);
});
app.listen(3000, () =>{
console.log("Listen in port 30000");
});
I figure out what went wrong. Here
app.use(express.json);
Should be This,
app.use(express.json());
You have to parse your json data inorder to consume it.
check the following code.
install this package.
npm i body-parser
and use it with your express object as below
let bodyParser = require('body-parser')
app.use(bodyParser.json())

How can I read the data received in application/x-www-form-urlencoded format on Node server?

I'm receiving data on a webhook URL as a POST request. Note that the content type of this request is application/x-www-form-urlencoded.
It's a server-to-server request. And On my Node server, I simply tried to read the received data by using req.body.parameters but resulting values are "undefined"?
So how can I read the data request data? Do I need to parse the data? Do I need to install any npm module? Can you write a code snippet explaining the case?
If you are using Express.js as Node.js web application framework, then use ExpressJS body-parser.
The sample code will be like this.
var bodyParser = require('body-parser');
app.use(bodyParser.json()); // support json encoded bodies
app.use(bodyParser.urlencoded({ extended: true })); // support encoded bodies
// With body-parser configured, now create our route. We can grab POST
// parameters using req.body.variable_name
// POST http://localhost:8080/api/books
// parameters sent with
app.post('/api/books', function(req, res) {
var book_id = req.body.id;
var bookName = req.body.token;
//Send the response back
res.send(book_id + ' ' + bookName);
});
You must tell express to handle urlencoded data, using an specific middleware.
const express = require('express');
const app = express();
app.use(express.urlencoded({
extended: true
}))
And on your route, you can get the params from the request body:
const myFunc = (req,res) => {
res.json(req.body);
}
The accepted answer uses express and the body-parser middleware for express. But if you just want to parse the payload of an application/x-www-form-urlencoded ContentType sent to your Node http server, then you could accomplish this without the extra bloat of Express.
The key thing you mentioned is the http method is POST. Consequently, with application/x-www-form-urlencoded, the params will not be encoded in the query string. Rather, the payload will be sent in the request body, using the same format as the query string:
param=value&param2=value2
In order to get the payload in the request body, we can use StringDecoder, which decodes buffer objects into strings in a manner that preserves the encoded multi-byte UTF8 characters. So we can use the on method to bind the 'data' and 'end' event to the request object, adding the characters in our buffer:
const StringDecoder = require('string_decoder').StringDecoder;
const http = require('http');
const httpServer = http.createServer((req, res) => {
const decoder = new StringDecoder('utf-8');
let buffer = '';
req.on('data', (chunk) => {
buffer += decoder.write(chunk);
});
req.on('end', () => {
buffer += decoder.end();
res.writeHead(200, 'OK', { 'Content-Type': 'text/plain'});
res.write('the response:\n\n');
res.write(buffer + '\n\n');
res.end('End of message to browser');
});
};
httpServer.listen(3000, () => console.log('Listening on port 3000') );
Express 4.16+ has implemented their own version of body-parser so you do not need to add the dependency to your project.
app.use(express.urlencoded()); //Parse URL-encoded bodies
Non-deprecated alternative to body-parser in Express.js
If you are creating a NodeJS server without a framework like Express or Restify, then you can use the NodeJS native querystring parser. The content type application/www-form-urlencoded format is the same as the querystring format, so we can reuse that built-in functionality.
Also, if you're not using a framework then you'll need to actually remember to read your body. The request will have the method, URL, and headers but not the body until you tell it to read that data. You can read up about that here: https://nodejs.org/dist/latest/docs/api/http.html
If you are using restify, it would be similar:
var server = restify.createServer()
server.listen(port, () => console.log(`${server.name} listening ${server.url}`))
server.use(restify.plugins.bodyParser()) // can parse Content-type: 'application/x-www-form-urlencoded'
server.post('/your_url', your_handler_func)

Mailgun webhook POST body seems empty

I'am trying to handle http post message from Mailgun bounce webhook. When sending it to Mailgun's Postbin service all data is found of course. But I'm now sending that POST to my localhost server for development purposes and all I get is empty json array. I use Test Webhook.
Intent is to keep this simple as possible besides our main service. That for I started using nodejs/expressjs to create stand alone webservice to work as relay to receive POST messages of email bounces from Mailgun and inform admins about bounced email addresses.
Now I can't figure why I don't get the same data as is visible in Postbin.
var express = require('express');
var app = express();
var bodyParser = require('body-parser');
var mailgun = require('mailgun-js')({apiKey: 'key-...', domain: 'mymailgundomain.com'});
app.use(bodyParser.urlencoded({
extended: true
}));
function router(app) {
app.post('/webhooks/*', function (req, res, next) {
var body = req.body;
if (!mailgun.validateWebhook(body.timestamp, body.token, body.signature)) {
console.error('Request came, but not from Mailgun');
res.send({ error: { message: 'Invalid signature. Are you even Mailgun?' } });
return;
}
next();
});
app.post('/webhooks/mailgun/', function (req, res) {
// actually handle request here
console.log("got post message");
res.send("ok 200");
});
}
app.listen(5000, function(){
router(app);
console.log("listening post in port 5000");
});
I'm running this from Mailgun's Test Webhook using url like http://mylocalhostwithpublicip.com:5000/webhooks/mailgun
Code structure is copied from https://github.com/1lobby/mailgun-js. Probably I'm missing something fundamental here as I can't figure it out myself.
The reason you're not seeing req.body populated is because the body-parser module does not support multipart/form-data requests. For those kinds of requests you need a different module such as multer, busboy/connect-busboy, multiparty, or formidable.
If your content-type (shown by logging console.dir(req.headers['content-type'])) is 'application/x-www-form-urlencoded', and you're using body-parser, try adding the following line:
bodyParser = require('body-parser')
app.use(bodyParser.urlencoded({ extended: false }))
to make it work with multer, you can use .any() (version 1.1.0)
for me it worked like this: (assuming multer is included and declared as "multer")
post('/track', multer.any(),function(req, res){
//if body is a string, parse the json
var data=(typeof req.body=='string')?JSON.parse(req.body):req.body;
//if data is an object but you can't verify if a field exists with hasOwnProperty, force conversion with JSON
if(typeof data=='object' && typeof data.hasOwnProperty=='undefined')
data=JSON.parse(JSON.stringify(data));
//data is your object
});
var multer = require('multer');
var msg = multer();
post('/track', msg.any(), function(req, res){
console.log(req.body);
}
I make a custom parser for get data in req.body when the Content-type = 'multipart/alternative'
https://github.com/josemadev/Multiparser/

Resources