I want to track users that are online at the moment.
The definition of being online is when they are on the index page of the website which has the chat function.
So far, all I can think of is setting a cookie for the user and, when the cookie is found on the next visit, an ajax call is made to update a table with their username, their status online and the time.
Now my actual question is, how can I reliably turn their status to off when they leave the website? The only thing I can think of is to set a predetermined amount of time of no user interaction and then set the status to off.
But what I really want is to keep the status on as long as they are on the site, with or without interaction, and only go to off when they leave the site.