One solution could be using session variables. I can make a script that looks for this variable, if it doesn't exist means that the user is entering the site. Then I set this variable with current time. The script it's in each page, and it will be reading this variable via AJAX each x seconds and I'll know when the user is in my site since two minutes.
I don't know if it's right or not (I've not implemented yet), but I'm not pretty sure if session is the best way. If the user leaves the page but has other navigator windows opened, the session doesn't expire, and if he enters the site again, the counter will not be reset.
So, two questions:
- Is there a better method to have more control on the real entering and exiting?
- If not, is my above approach right?