How to access the request body when POSTing using Node.js and Express?
Javascriptnode.jsExpressJavascript Problem Overview
I have the following Node.js code:
var express = require('express');
var app = express.createServer(express.logger());
app.use(express.bodyParser());
app.post('/', function(request, response) {
response.write(request.body.user);
response.end();
});
Now if I POST something like:
curl -d user=Someone -H Accept:application/json --url http://localhost:5000
I get Someone
as expected. Now, what if I want to get the full request body? I tried doing response.write(request.body)
but Node.js throws an exception saying "first argument must be a string or Buffer" then goes to an "infinite loop" with an exception that says "Can't set headers after they are sent."; this also true even if I did var reqBody = request.body;
and then writing response.write(reqBody)
.
What's the issue here?
Also, can I just get the raw request without using express.bodyParser()
?
Javascript Solutions
Solution 1 - Javascript
Starting from express v4.16 there is no need to require any additional modules, just use the built-in JSON middleware:
app.use(express.json())
Like this:
const express = require('express')
app.use(express.json()) // <==== parse request body as JSON
app.listen(8080)
app.post('/test', (req, res) => {
res.json({requestBody: req.body}) // <==== req.body will be a parsed JSON object
})
Note - body-parser
, on which this depends, is already included with express.
Also don't forget to send the header Content-Type: application/json
Solution 2 - Javascript
Express 4.0 and above:
$ npm install --save body-parser
And then in your node app:
const bodyParser = require('body-parser');
app.use(bodyParser);
Express 3.0 and below:
Try passing this in your cURL call:
--header "Content-Type: application/json"
and making sure your data is in JSON format:
{"user":"someone"}
Also, you can use console.dir in your node.js code to see the data inside the object as in the following example:
var express = require('express');
var app = express.createServer();
app.use(express.bodyParser());
app.post('/', function(req, res){
console.dir(req.body);
res.send("test");
});
app.listen(3000);
This other question might also help: https://stackoverflow.com/questions/8742982/how-to-receive-json-in-express-node-js-post-request
If you don't want to use the bodyParser check out this other question: https://stackoverflow.com/a/9920700/446681
Solution 3 - Javascript
As of Express 4, the following code appears to do the trick.
Note that you'll need to install body-parser
using npm
.
var express = require('express');
var bodyParser = require('body-parser');
var app = express();
app.use(bodyParser.urlencoded({ extended: false }));
app.listen(8888);
app.post('/update', function(req, res) {
console.log(req.body); // the posted data
});
Solution 4 - Javascript
For 2019, you don't need to install body-parser
.
You can use:
var express = require('express');
var app = express();
app.use(express.json())
app.use(express.urlencoded({extended: true}))
app.listen(8888);
app.post('/update', function(req, res) {
console.log(req.body); // the posted data
});
Solution 5 - Javascript
var express = require('express');
var bodyParser = require('body-parser');
var app = express();
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json())
var port = 9000;
app.post('/post/data', function(req, res) {
console.log('receiving data...');
console.log('body is ',req.body);
res.send(req.body);
});
// start the server
app.listen(port);
console.log('Server started! At http://localhost:' + port);
This will help you. I assume you are sending body in json.
Solution 6 - Javascript
You should not use body-parser
it is deprecated. Try this instead
const express = require('express')
const app = express()
app.use(express.json()) //Notice express.json middleware
The app.use()
function is used to mount the specified middleware function(s) at the path which is being specified. It is mostly used to set up middleware for your application.
Now to access the body just do the following
app.post('/', (req, res) => {
console.log(req.body)
})
Solution 7 - Javascript
This can be achieved without body-parser
dependency as well, listen to request:data
and request:end
and return the response on end of request, refer below code sample. ref:https://nodejs.org/en/docs/guides/anatomy-of-an-http-transaction/#request-body
var express = require('express');
var app = express.createServer(express.logger());
app.post('/', function(request, response) {
// push the data to body
var body = [];
request.on('data', (chunk) => {
body.push(chunk);
}).on('end', () => {
// on end of data, perform necessary action
body = Buffer.concat(body).toString();
response.write(request.body.user);
response.end();
});
});
Solution 8 - Javascript
In my case, I was missing to set the header:
"Content-Type: application/json"
Solution 9 - Javascript
Try this:
response.write(JSON.stringify(request.body));
That will take the object which bodyParser
has created for you and turn it back into a string and write it to the response. If you want the exact request body (with the same whitespace, etc), you will need data
and end
listeners attached to the request before and build up the string chunk by chunk as you can see in the json parsing source code from connect.
Solution 10 - Javascript
If you're lazy enough to read chunks of post data. you could simply paste below lines to read json.
Below is for TypeScript similar can be done for JS as well.
app.ts
import bodyParser from "body-parser";
// support application/json type post data
this.app.use(bodyParser.json());
// support application/x-www-form-urlencoded post data
this.app.use(bodyParser.urlencoded({ extended: false }));
In one of your any controller which receives POST call use as shown below
userController.ts
public async POSTUser(_req: Request, _res: Response) {
try {
const onRecord = <UserModel>_req.body;
/* Your business logic */
_res.status(201).send("User Created");
}
else{
_res.status(500).send("Server error");
}
};
> _req.body should be parsing you json data into your TS Model.
Solution 11 - Javascript
I'm absolutely new to JS and ES, but what seems to work for me is just this:
JSON.stringify(req.body)
Let me know if there's anything wrong with it!
Solution 12 - Javascript
The accepted answer only works for a body that is compatible with the JSON format. In general, the body can be accessed using
app.use(
Express.raw({
inflate: true,
limit: '50mb',
type: () => true, // this matches all content types
})
);
like posted here. The req.body
has a Buffer
type and can be converted into the desired format.
For example into a string via:
let body = req.body.toString()
Or into JSON via:
let body = req.body.toJSON();
Solution 13 - Javascript
Install Body Parser by below command
$ npm install --save body-parser
Configure Body Parser
const bodyParser = require('body-parser');
app.use(bodyParser);
app.use(bodyParser.json()); //Make sure u have added this line
app.use(bodyParser.urlencoded({ extended: false }));
Solution 14 - Javascript
What you claim to have "tried doing" is exactly what you wrote in the code that works "as expected" when you invoke it with curl.
The error you're getting doesn't appear to be related to any of the code you've shown us.
If you want to get the raw request, set handlers on request
for the data
and end
events (and, of course, remove any invocations of express.bodyParser()
). Note that the data
events will occur in chunks, and that unless you set an encoding for the data
event those chunks will be buffers, not strings.
Solution 15 - Javascript
You use the following code to log post data:
router.post("/users",function(req,res){
res.send(JSON.stringify(req.body, null, 4));
});