How to keep session alive without reloading page?

You can use javascript XHR, or as others call it, AJAX.

• http://api.jquery.com/jQuery.ajax/
• http://api.jquery.com/jQuery.get/

Using ajax you can call a php script that refreshes your session every 10 minutes. :)

---

This is as far as i can go to "exact".

javascript

var refreshSn = function ()
{
    var time = 600000; // 10 mins
    setTimeout(
        function ()
        {
        $.ajax({
           url: 'refresh_session.php',
           cache: false,
           complete: function () {refreshSn();}
        });
    },
    time
);
};

// Call in page
refreshSn()

refresh_session.php

<?php
session_start();

// store session data
if (isset($_SESSION['id']))
$_SESSION['id'] = $_SESSION['id']; // or if you have any algo.
?>

---

Anyway, another solution would be to extend the session time for the test page only using the solution presented here

How do I expire a PHP session after 30 minutes?

All you need is this (uses jQuery for the $.post):

JavaScript (put this inside your onload-function or something)

setInterval(function(){
  $.post('path/to/refresh_session.php');
},600000); //refreshes the session every 10 minutes

refresh_session.php

<?php
  session_start();

  // if you have more session-vars that are needed for login, also check 
  // if they are set and refresh them as well
  if (isset($_SESSION['token'])) { 
    $_SESSION['token'] = $_SESSION['token'];
  }
?>

The biggest change is in the JavaScript--you don't need a whole function, just one line.

---

EXTRA INFO

Although I think it's enough to just call session_start() in the php, if I read this right (http://nl3.php.net/function.session-start):

The read callback will retrieve any existing session data (stored in a special serialized format) and will be unserialized and used to automatically populate the $_SESSION superglobal when the read callback returns the saved session data back to PHP session handling.

And during testing I only put the above code on my visitor page, and not on the admin page. But I had both pages open in the same browser (Chrome), and the admin page stayed logged in as well, at least for over an hour (didn't check any longer). BUT, I don't know if it still works if you only use session_start(), without manually refreshing any session-var at all..

Either way, I like to be sure that the session-vars I need are really still there:)