get the last updated mongo id from nodejs - node.js

Question

am working on push notifications using mongodb and nodejs.
I can see the newly added notifications (which are addede in Mongodb) in my browser
But, if I updated the record, the value is not updating in the browser
// if no error get reference to colelction named: 'notifications'
db.collection('notifications', function(err, collection){
if(err) {
throw err;
}
// if no error apply a find() and get reference to doc
collection.find().sort({
$natural: -1
}).limit(1).nextObject(function(err, doc) {
// Rewind the cursor, resetting it to point to the start of the query
if(err) {
throw err;
}
// using tailable cursor get reference to our very first doc
var query = {
_id: {
$gt: doc._id
}
};
var options = {
tailable: true,
awaitdata: true,
numberOfRetries: -1
};
var cursor = collection.find(query, options).sort({
$natural: 1
});
// This function will take cursor to next doc from current as soon as 'notifications' database is updated
function next() {
cursor.nextObject(function(err, message) {
if (err) throw err;
console.log(message.message);
mdsok.volatile.emit('notification', message);
next();
});
}
// what you need to do is: call it first time
next();
});
This is what i am doing in my code.
what should I do to update the value in the browser when I update the same in db.
Please help me . Thanks in advance!

Answer 1

My problem was solved upto some extent.
var http = require('http'),
fs = require('fs'),
// NEVER use a Sync function except at start-up!
index = fs.readFileSync('index.html');
// Send index.html to all requests
var app = http.createServer(function(req, res) {
res.writeHead(200, {
'Content-Type': 'text/html'
});
res.end(index);
});
// Socket.io server listens to our app
var io = require('socket.io').listen(app);
var MongoClient = require('mongodb').MongoClient;
function getdata(){
MongoClient.connect("mongodb://127.0.0.1:27017/test", function(err, db) {
var collection = db.collection('my_collection');
var stream = collection.find({
//'_id': new ObjectID('53eb6f2e75fd7ad00d000029')
//_id: ObjectID.createFromHexString("53eb6f2e75fd7ad00d000029")
}).stream();
stream.on("data", function(item) {
io.sockets.emit('db_status', {
status: item.status
});
prev = item.status;
console.log(prev);
});
stream.on("end", function() {
console.log("Done loading data");
});
});
}
// Send current time every 5 secs
setInterval(getdata, 5000);
// Emit welcome message on connection
io.sockets.on('connection', function(socket) {
socket.emit('welcome', {
message: 'Welcome!'
});
socket.on('i am client',function(data){
console.log(data);
});
});
app.listen(3000);
for every 5 secs, i am hitting the db and getting the value and displaying it in the browser.
To get the newly inserted object, we are using .nextObject() in node.js
Is there any way to get the updated object of the db as above in node.js.