I am trying to learn node js. I am tryng to put a post request from axios by frontend but node js is responding with empty object.
Here is the code
node js
var express = require("express");
var app = express();
var cors = require("cors");
app.use(cors());
var bodyParser = require("body-parser");
var urlencodedParser = bodyParser.urlencoded({ extended: false });
// This responds with "Hello World" on the homepage
app.get("/", function (req, res) {
console.log("Got a GET request for the homepage");
res.send("Hello GET");
});
app.post("/", urlencodedParser, function (req, res) {
console.log(req.body);
res.send("Hello GET");
});
var server = app.listen(8081, function () {
var host = server.address().address;
var port = server.address().port;
console.log("Example app listening at http://%s:%s", host, port);
});
frontend
axios.post("http://localhost:8081/", { body: "dan" })
.then((e) => console.log(e))
The response is an empty object.
What should I do?
By default your axios code:
axios.post("http://localhost:8081/",{body:"dan"}).then((e) => console.log(e))
will send the body of the POST request as JSON. Quoted directly from the axios doc.
By default, axios serializes JavaScript objects to JSON
So, you need JSON middleware on your Express server to read and parse that JSON body. Without middleware that is looking for that specific content-type, the body of the POST request will not be read or parsed and req.body will remain empty.
app.post('/', express.json(), function (req, res) {
console.log(req.body);
res.send('Hello POST');
});
Note, there is no need to separately load the body-parser module as it is built-in to Express.
Or, if you want the request to be sent as application/x-www-form-urlencoded content-type, then you would need to encode the data that way and send it as the data in your axios request and set the content-type appropriately.
These request bodies can be handled by the express.urlencoded() middleware in the same way as express.json().
You should use bodyParser.json(), to get the data sent in req.body.
var bodyParser = require('body-parser');
app.use(bodyParser.json());
We should parse request body before access it using middleware in the following way
app.use(bodyParser.json());
Im trying to send a POST from a client connected to this server to a external URL. I get a lot of 'CORS' errors. Im pretty sure that it's because i haven't allowed 'Access-Control-Allow-Origin' and etc on my Node.JS server. But i don't know how to do it. I have found another answers on the web, but none of them solved my problem.
Here is my server:
var app = require('express')();
var http = require('http').Server(app);
var io = require('socket.io')(http);
const { instrument } = require('#socket.io/admin-ui')
var bodyParser = require('body-parser')
var clientesConectados = [];
app.use( bodyParser.json() ); // to support JSON-encoded bodies
app.use(bodyParser.urlencoded({ // to support URL-encoded bodies
extended: true
}));
app.get('/', function(req, res){
//send the index.html file for all requests
res.sendFile(__dirname + '/index.html');
});
app.post('/', (request, res) => {
console.log("********************");
console.log(" >POST RECEBIDO!!");
console.log(res);
postData = request.body;
io.emit('message',postData);
console.log(postData);
});
http.listen(3000, function(){
console.log('listening on *:3000');
});
Express has a middleware for CORS. Link here
Install npm package called cors
After installing, on your file add this line app.use(cors()) will solve your issue of cors error I hope.
Install cors package in your application
npm install cors
And then add these two lines in there
var cors = require("cors");
app.use(cors())
Else there are ways that set through header or you could use a proxy in your frontend but using cors package is simpler
Here's my app.js file.
var express = require('express'),
bodyParser = require('body-parser'),
oauthServer = require('oauth2-server'),
oauth_model = require('./app_modules/oauth_model')
const app = express()
app.use(bodyParser.urlencoded({ extended: true }));
var jsonParser = bodyParser.json();
app.oauth = oauthServer({
model: oauth_model, // See below for specification
grants: ['password', 'refresh_token'],
debug: process.env.OAUTH_DEBUG,
accessTokenLifetime: 172800,
refreshTokenLifetime: 172800,
authCodeLifetime: 120,
});
// Oauth endpoint.
app.all('/oauth/token', app.oauth.grant());
// User registration endpoint.
app.post('/users', jsonParser, require('./routes/register.js'));
// Get user details.
app.get('/users', app.oauth.authorise(), require('./routes/users.js'));
app.post('/', app.oauth.authorise(), require('./routes/test.js'));
app.use(app.oauth.errorHandler());
app.listen(3000, function () {
console.log('Mixtra app listening on port 3000!')
})
When I send an invalid json body with POST request to localhost:3000/users the request goes to register.js and the validation code works there.
but strangely when I send valid JSON body, it says "Cannot POST /users" with a 404 Not Found HTTP status code and nothing in terminal log.
Note: I'm using postman to send the api requests.
It would be really great if someone could help me with this.
Thanks,
Joy
I don't see you using the jsonParser
You should use it before sending any json to it
app.use(jsonParser);
When using the following:
var app = require('express')();
var bodyParser = require('body-parser');
app.post('/test', bodyParser.json(), function(req, res) {
res.json(req.body);
});
var port = 4040;
app.listen(port, function() {
console.log('server up and running at port: %s', port);
});
and the following post from Postman:
I get an empty response. I've followed a lot of threads on using bodyParser.json() and for some reason I'm still receiving an empty object in response. What am I missing?
To make bodyParser.json works you should provide Content-Type header with value application/json in your requests.
A safer way to use body-parser would be to apply it as middleware for the entire app. The code will have to be refactored in this manner:
// Permit the app to parse application/x-www-form-urlencoded
app.use(bodyParser.urlencoded({ extended: false }));
// Use body-parser as middleware for the app.
app.use(bodyParser.json());
app.post('/test', function(req, res) {
res.json(req.body);
});
When you make a request on Postman, make sure to select the x-www-form-urlencoded tab as opposed to the raw tab.
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()?
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
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: 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
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
});
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
});
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)
})
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.
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();
});
});
In my case, I was missing to set the header:
"Content-Type: application/json"
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.
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();
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.
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!
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 }));
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.
You use the following code to log post data:
router.post("/users",function(req,res){
res.send(JSON.stringify(req.body, null, 4));
});