can you envoke a php function using javascript?

richblend

i mean, i cant quite get my head round it realy, but basically i wasnt to use the javascript onunload() function so that when the user closes the window, it activates a php function (that writes to the database that the user is no longer online). is there anyway of doing this?

cheers

drawmack

what you would have to do is onUnload pop up a new window and load a php script in that window then have that script write to the database and then use javascript to close the new window.

warning: expect upset visitors if you do this.

richblend

yeah, i thought that might be the case. so does anyone know how php forums and stuff liek that can tell when people are online or not?

drawmack

I've never looked into it but my guess would be inactive for x seconds = not currently in the system.

paulsbooker

the server can only know if you go offline if you tell it

so if you close your browser using the browsers close button
trap the onunload event and execute a script on your server
to tell the server the user has logged out

drawmack

Originally posted by paulsbooker
the server can only know if you go offline if you tell it

right but the server can assume anything the programmer tells it to.

So......

Step 1) Everytime the user performs an action the timestamp is written to the database.
Step 2) When you echo out people currently logged in you only echo those that have taken an action in the last x seconds.

There now you are assuming the person is not on the site if the have taken no action in x sections, I would say that 90 is good.