PHP session is coming back null

Question

I am trying to come up with a session timeout (first time). When ever I am calling the if statement it is getting a null for the $_SESSION variable. I have the session start in the header.php file at the top. When the user logs in it creates the session with this code:

public static function create_session($values) {
    foreach ( $values as $key => $value ) {
        if ($key != "password") {
            $_SESSION[$key] = $value;
        }           
    }

    $_SESSION["timestamp"] = time();
}

It then redirects to an index page wich only contains:

<?php
  echo "<pre>";
  print_r($_SESSION);
  echo "</pre>";
?>

This works, it prints all the session variables on the page just fine.

This is what prints out in the index.php file with the above code.

Array
(
  [id] => 33
  [first_name] => removed to not show name
  [last_name] => removed to not show name
  [email] => test@test.com
  [timestamp] => 1437486426
)

In my footer.php file I have some jquery running a timed function every 5 seconds calling the timeout.php file.

(function poll() {
   setTimeout(function() {
       $.ajax({ url: "timeout.php", success: function(data) {
            console.log(data);
       }, dataType: "json", complete: poll });
    }, 5000);
})();

The timeout php file only has this code in it:

if (isset($_SESSION)) {
    if ($_SESSION['timestamp'] + 10 * 60 < time()) {
        // session timed out
        echo json_encode(array('session' => $_SESSION, 'session_timestamp' => $_SESSION['timestamp'], 'timestamp_calculation' => $_SESSION['timestamp'] + 10 * 60, 'timeoutstatus' => 'timed out'));
    } else {
        // session ok
        echo json_encode(array('session' => $_SESSION, 'session_timestamp' => $_SESSION['timestamp'], 'timestamp_calculation' => $_SESSION['timestamp'] + 10 * 60, 'timeoutstatus' => 'not timed out'));
    }
} else {
    echo json_encode(array('session' => 'Session does not exits'));
}

For some reason I am getting the session does not exist. If I remove that part of the if statement and just test the timeout all the json array variables that call $_SESSION return null. I have no idea why this is. I appreciate your help.

In response to this being a duplicate. The original thought was that session_start() wasn't called. I had mentioned it was called in the first paragraph and it comes before all other php code. I have also confirmed that I can call the $_SESSION variable within the index page just fine. I am only getting an issue when trying to read it through my ajax function which is being called from my footer.php.

I don't see `session_start()` anywhere. I don't see how your index page can work like you say it does. — John Conde, Jul 21 '15 at 13:59
Do you start a session? session_start(); http://php.net/session_start — Webice, Jul 21 '15 at 13:59
session_start() function is at the in the header.php file so it is called no matter what. I did not include that in the code here. so heirarchy goes header.php with session_start() -> index.php -> footer.php — user2112618, Jul 21 '15 at 14:03

score 1 · Answer 1 · answered Jul 21 '15 at 19:07

You have not start session in timeout.php file and/or not include your header.php in to this file so session will never start in timeout.php. That's y session is undefine in timeout.php file.

You can add condition in timeout.php like :

if(!isset($_SESSION)) session_start();

PHP session is coming back null

1 Answers1