Updating Mongo document from Node

Question

Updating Mongo document from Node

so I am inserting a document into mongo db as such

io.sockets.on('connection', function (socket) {
    connectLog(socket.handshake.address.address);

function connectLog(ipAddress) {
   db.collection('tracking', function (err, collection) {
        var currentTime = new Date();
        var doc={"ip":ipAddress, "connect": currentTime, "culture": "en" };
        collection.insert(doc, function () { });
    });

}

I have another event

function logout(id, disconnect) {

I'd like to update (or replace?) that record and add disconnect: (time) to it. How would I go about doing this? This way I can tell when a person connects and when they disconnect from the chat.

I am using socket.io so I'll know their exact disconnect time

Thank you in advance

node.js
mongodb
socket.io

Answer 1

First, read this about explicit vs. implicit disconnects: Socket.io: How to handle closing connections?. Basically, your handler for explicit logouts (which are good!) should call the same code as your disconnect handler, in case the user doesn't get a chance to explicitly logout.

So in addition to your logout code, you'll also want:

socket.on('disconnect', handleDisconnect)

And in that disconnect/logout handler, you'll want to find the most recent connection document for that user and update it.

collection.findAndModify(
 {"address" : address}, //same address 
 [['connect', 'descending']], //the most recent, findAndModify only changes the first doc
 {$set: {disconnect: currentTime}}, //set the disconnect time
 function(err, object){/*deal with errors*/}
)