How to send data from server to client in nodejs?

Question

I'm running a server in nodejs with express to serve an html form within the file index.html to a client like this:

var express = require('express');
var bodyParser = require('body-parser');
var app = express();
app.use(bodyParser());
app.get('/', function(req, res){res.sendfile('index.html');});
app.post('/', function(req, res){
  res.json(req.body);
});

app.listen(8080);

req.body gives me the form input. Now I need to send back req.body to the client, and to do this I'm using ajax on the client side (inside index.html) like this:

var data;
$('#submit').click(function()
{
    console.log('Button Clicked');
    $.ajax({
        url: '/',
        type:'POST',
        data: data,
        dataType: 'json',
        }).done(function(data) {

            console.log(data);
        });      
})

However when I click the button submit I get Object {} in the browser console and not the form input. What am I missing here?

I don't think you're using the body parser correctly. github.com/expressjs/body-parser — user400654
– user400654, Commented May 20, 2015 at 21:03
You are sending a JSON string and your server is converting to a JSON Object, which you are then returning - but not as a string. Try res.json(JSON.stringify(req.body)); — Vic
– Vic, Commented May 20, 2015 at 21:06
I think you should use bodyparser something like app.use(bodyParser.json({type: 'application/json'})); — user1021726
– user1021726, Commented May 20, 2015 at 21:41

Andrew Lavers · Accepted Answer · 2015-05-20 22:24:29Z

1

There are two issues in your code:

First, as the comments mention, bodyParser() is deprecated, you should be using the specific bodyParser middlewares (json, text, urlencoded, raw). So in your case:

app.use(bodyParser.json())

Second, your client side call to jQuery.ajax should stringify your data. Like this:

$('#submit').click(function()
{
    console.log('Button Clicked');
    $.ajax({
        url: '/',
        type:'POST',
        data: JSON.stringify(data),
        dataType: 'json',
        }).done(function(data) {
            console.log(data);
        });      
})

answered May 20, 2015 at 22:24

Andrew Lavers

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2 Comments

David Over a year ago

also didn't work. Do you know where can I find any clear examples of this?

Andrew Lavers Over a year ago

It works for me... Are you assigning var data a value or is it undefined like in your code sample? What do you mean by 'it doesn't work'?

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