Global Functions

lquidsilver

Alrighty so I am completely lost as to how to go about doing this script. So I'll post it here and see what suggestions I get from all you mad geniuses out there.

Okay I have a website I am working on and in one particular part I want to create an exploration system. The way I would like this system to work is a person clicks on a section of the map which will take them to another page and there will be roughly 5-6 villages there, which then the person will proceed to click one of the villages.(This is the hard part) Now when the person clicks on this village I want my page to create a global timer (sort of speak) where all other users have roughly 2 minutes to join that session that that first person created when he/she clicked the village. Then after 2 minutes the session is closed and no one is permitted in that session. The session itself should last roughly 1 minute and after that one minute is up the session will end and everything goes back to normal, allowing another user to click on that village and start this process all over. The problem I seem to be running into is how to create a global function like that.

kakki

maybe you can create a file ...
so the "global function" would check, if that file exists ...
so:
if the user calls the page first time, the file will be created. the first page
creates a javascript-timer, that will call the second page, if the time is over.

when the second page will be called, it erases the created file
( no one can enter after that )

lquidsilver

Could you type up a quick example, that would help greatly. Other than that I think you may be on to something here! EDIT: Alright the real question here is how do i make the timer global because it seems to me that when the user creates the file for the first time it will create a timer that only HE/SHE can see.

bpat1434

A global timer could easily be a text-file on the server which is the X,Y coordinates and then a timestamp. Something like:

25,120|123456789
82,610|918471850
153,206|018591864

Then you can look up the XY coordinate and time-stamp. A Cron Job could then read the file every minute and check the timestamps to see which one is over a minute old and remove the line.

You could also do this with a database which might make it faster. You store the coordinates and look up based on coordinates to see if the slot is open. You could have an "open" flag which is open when one person clicks on it, and the cron which updates every minute would automatically close them if they're over 2 minutes old, and remove them if they're 3 or more minutes old. So if they're not in the table, then it's free to be open, if it's there but "closed" then they can't join, otherwise it's open and they can join.

That's pretty much the best way I can see this being implemented.

kakki

i just got an another idea ( bpat1434's idea included ) ...
a file, thats php-code that saves the first run

<?php
if ( is_file( 'timer.php' ) )
{
require_once 'timer.php';
}
else
{
$handle=fopen('timer.php','w');
fwrite( $handle, '<?php $STARTED='.date( 'U', mktime() ).'; ?>' );
fclose( $handle );
require_once 'timer.php';
}

// i can access the time now from any run of this script( new users ... )

// check the timer
if ( date( 'U', mktime() ) - $STARTED > 60 )
{
// delete timer.php
// closed 
}
?>

this is prone to several attacks ... you should keep the created 'timer.php' safe from outside write-access

bpat1434

What if you have 30 files? Then the timer would be "reset" (or falsely used) with each request. You could use that method if you [man]md5[/man] or [man]sha1/man the filename of the requested file. Then see if it's there on the next request.

kakki

yup ... you need a file for each joined "session"

lquidsilver

So would this be server side? The problem I seem to be running into now is the fact that when the original person who clicks the link redirects away from the page the counter stops. I need it to keep going regardless of where they go on the website

bpat1434

The "counter" isn't a counter. If you write a temp file, and make the contents of it have a variable with the timestamp of the original request, then read it.

You could have this in the top of every file:

<?php

$filename = md5(basename(__FILE__));
if(is_file($filename))
{
    include($filename);
}
else
{
    $timestamp = time();
    $fp = fopen($filename, 'a+');
    fwrite($fp, '<?php $timestamp = ' . $timestamp . '; ?>');
    fclose($fp);
}

$join_cutoff = $timestamp + 120; // Add 2 minutes to the initial session
$session_end = $join_cutoff + 60; // Leave session open for a minute

if(time() < $join_cutoff)
{
    // Allow them to join the session
}
elseif(time() > $join_cutoff && time() < $session_end
{
    // Deny them access
}