How to check who is currently logged in?

yourchild

How do I go about checking to see who is logged onto my website?

if(isset($_SESSION['userID'])){
display content for logged in user
}
else{
display content for non-logged in user
}

this will tell me what to echo depending if the user is logged in or not.

But how do I check every user account in the db and determine who is currently logged in?

If a user logs into the site, I can set a 'loggedIn' field of the user's table in the db to 'true'.

Then when the user clicks the log out button, I can easily set that field to false...but if the user closes the browser or navigates to another site, I am without a clue on how to update the db...

Any ideas???

laserlight

You need to store the time of each user's last page load. If this time was recent, you assume that the user is still logged in.

Xager

Make sure that each page updates the time in the DB

yourchild

But how do I get into the database at the end when the user closes the browser? What function has the feature of being lastly called when the browser is closed, or when the user navigates away?

Am I left with "onunload" in combination with ajax, in order for me to update the database? can you give me more details on using the time() function?

This function gives me the current time (in seconds) when the page is loaded.

Let me run through the scenario to see how this is implemented...

the user visits:

pageA.php - call time() = 1 second, update database....
the user sits at pageA.php for 5 minutes = 5 X 60 = 300 seconds.

the user browses to pageB.php - call time() = 300 seconds, update database..

Then he closes the browser...how on earth would I call time() by then????

laserlight

But how do I get into the database at the end when the user closes the browser?

You don't. Just assume that the user has logged out after some time.

yourchild

Dont I need to go into the database and update that field in the user table "is_logged_in" to 'no' to determine who is currently online?

I'm sure you've seen myspace. The user can sit in a chatroom all day and not be logged off.

If I used the time() method (assuming I knew how to), this method would log me off after maybe 1 hr? of not uploading a new page. That wouldnt work for a chatroom implementation, which I'm currently working on....

There has to be some way to access the database once the user closes the page...

the only thing I can summon is 'onunload', using javascript, in combination with ajax technology for me to get a hold of the db.

but I was hoping there'd be something else available, since some user might turn off javascript in their browsers =\

Xager

PHP cannot recive any data after the page has loaded, only before.
Only way is with javascript AFAIK

bradgrafelman

The method most commonly used (e.g. here on the forums) that laserlight is trying to explain is to simply poll the DB to see which users have had activity within the last x minutes - these users are presumed to be "logged in." It really has nothing to do with a boolean value "logged_in."

If you wanted it to be very accurate, then you'd need to rely on solutions such as AJAX where you could send a "heartbeat" every few seconds to let the server know that the user is still on your website. If the heartbeat isn't received for a certain amount of time, then you can presume that the page was closed.

yourchild

This is a good way to check for active users...my ajax would constantly scan the db and look for a 'large' time gap from the user's last uploaded page..

But my situation is a bit different because i am building a chatroom and the user is allowed to sit in the chatroom for as long as he/she wants...

actually...I think i can get this working using that method laser is talking about even for the chatroom...something just clicked in my head...

::back to work::

laserlight

But my situation is a bit different because i am building a chatroom and the user is allowed to sit in the chatroom for as long as he/she wants...

Ah, but you have to check the database periodically to update the chat with replies. This process of checking and downloading new replies can count as a page load, and at the same time, it can retrieve the updated list of online users.