Why my model does not get synced? - socket.io

Question

I've written my first program with racer. It displays a simple text box manually bound to 'col.doc.prop' path. When I change the value, it does not apply to the store at server.
What causes my subscribed model not to get sync with server?
Server code:
var fs = require('fs');
var io = require('socket.io');
var racer = require('racer');
var mongo = require('racer-db-mongo');
racer.use(mongo);
racer.js({
entry: __dirname + '/client.js'
}, function(err, js) {
return fs.writeFileSync(__dirname + '/script.js', js);
});
var express = require('express');
var server = express.createServer();
server.use(express.static(__dirname));
server.get('/', function(req, res)
{
var model = store.createModel();
model.subscribe('col.doc', function(err, doc)
{
var prop = doc.get('prop');
if (!prop)
{
doc.set('prop', 123);
store.flush();
}
model.ref('_doc', doc);
model.bundle(function(bundle)
{
var client = require('fs').readFileSync('./client.html', 'utf-8');
client = client.replace('_init_', bundle.toString());
res.send(client);
});
});
});
var store = racer.createStore(
{
listen: server,
db:
{
type: 'Mongo',
uri: 'mongodb://localhost/racerdb'
}
});
store.set('col.doc.prop', 123);
store.flush();
server.listen(3001);
Client code:
useRacer = function()
{
var socket = io.connect('http://localhost:3001');
var racer = require('racer');
process.nextTick(function() {
racer.init(this.init, socket);
return delete this.init;
});
racer.on('ready', function(model)
{
addListener = document.addEventListener ? function(el, type, listener) {
return el.addEventListener(type, listener, false);
} : function(el, type, listener) {
return el.attachEvent('on' + type, function(e) {
return listener(e || event);
});
};
var element = document.getElementById('prop');
var listener = function()
{
var val = element.value;
model.set('col.doc.prop', val);
};
addListener(element, 'keyup', listener);
var upgrade = function(id, value)
{
if (model.connected)
{
var prop = model.get('col.doc.prop');
element.value = prop;
}
else
model.socket.socket.connect();
};
model.on('connectionStatus', upgrade);
model.on('set', 'con.*', upgrade);
});
};

Answer 1

The problem solved by changing some lines of the client code:
model.set('col.doc.prop', val) ==> model.set('_doc.prop', val)
model.get('col.doc.prop') ==> model.get('_doc.prop')
model.on('set', 'con.', upgrade) ==> model.on('set', '', upgrade)