Make AJAX request using mootools and node.js with expressjs - ajax

Question

I'm trying establish an AJAX connection on node 0.10.3 using mootools. My code is:
Client
var ajax = new Request({
url: '/register',
method: 'post',
onSuccess: function(responseText){
console.log(responseText);
}
})
var json = {data:'data'};
ajax.send(JSON.stringify(json));
//ajax.send(json);
Server
var express = require('express');
var app = express();
app.use(express.static(__dirname + '/public'));
app.listen(1344);
app.post('/register', function(req,res){
//Auth.register()
console.log(req.body);
res.contentType('json');
res.send({ some: JSON.stringify({response:'json'}) })
})
The connection is working Ok. On the client I get the response. So the console.log(responseText) inside the OnSucces method is printing the correct value.
But on the server side, the console.log(req.body) is undefined.
I have a few doubts here. Does mootools converts the javascript object to a json string? Is it necessary to convert de object at all? What is the correct way of sending information trough AJAX to node? Is this ajax.send(JSON.stringify(json)); OK? Or is it like this ajax.send(json);?
Do I need to specify the headers to be json?
Apart for solving the particular problem, it would be nice some article, o some feedback to definitely clarify this concepts around node.js.
EDIT
I'm going to post the correct code, for those who are facing a similar problem. Noah was right about the parser, but there is another detail, the parser is expecting for the key data. Luckily I was using data as example!
Client
var ajax = new Request({
url: '/register',
method: 'post',
onSuccess: function(responseText){
console.log(responseText); //Logs "some": "{\"response\":\"json\"}"
}
})
ajax.send({data:{ok:'OK'}});
Server
var express = require('express');
var app = express();
app.use(express.static(__dirname + '/public'));
app.use(express.bodyParser());
app.listen(1344);
app.post('/register', function(req,res){
console.log(req.body); //logs {ok:'OK'}
res.contentType('json');
res.send({ some: JSON.stringify({response:'json'}) })
})

Answer 1

In the code you posted you are missing the bodyParser middleware app.use(express.bodyParser().
After you add the bodyParser middleware you will be able to access req.body
var express = require('express');
var app = express();
app.use(express.bodyParser()
app.use(express.static(__dirname + '/public'));
app.use(app.router)