Question

Not sure if this is too open-ended of a question for StackOverflow but, I’m trying to make a basic chat client using AJAX, php and mysql. Users can send messages to the chat, but they can’t see which other users are in the chat. Is there a good way to track which users are viewing a webpage and which have left?

Answer 1

the simplest solution is to have a database that records sessions, or at least a “last logged in” column in your database. once a user has logged in, it should reflect in the database that he or she has logged in using a time stamp. this session should auto expire in a given amount of time (like say auto logout, or in others the “idle” status)

then have an AJAX “heartbeat” to check the database if that user has logged out or expired or idle as well as return a list of un-expired users.