After plenty of debugging it seems the problem was (embarrassingly) in my database session code, not a typical session problem. You can see my answer relating it here - Thanks
I understand this may be a duplicate of similar questions (e.g. one, two, three) but despite following what seems to be the best practices for this I'm still having problems.
When using the session_set_save_handler() to use my database session class the session data is cleared when the session begins on session2.php after being redirected from session1.php.
An overview of my observations:
- Data is saved into the database correctly in session1.php
- Data is lost on session_start() in session2.php
- Data is still in database after the redirect and before session_start() is called in session2.php
- Session ID remains the same and is stored in a cookie which is being sent back to the server in the request headers correctly
- Using PHP's default Session handling it works okay
And note:
- exit() used after header()
- session_start() on every page before output
Have I made a silly typo? Made a daft error? Or is this a strange quirk?
Thanks in advance for any help offered.
Here's the code (extracted into testing files while fixing this issue):
session1.php
<?php
require_once('session.php');
session_start();
$_SESSION['KEY'] = 'VALUE PHPSESSID: ' . session_id();
session_write_close();
header('Location: session2.php');
exit;
session2.php
<?php
require_once('session.php');
session_start();
// Nothing?
var_dump( $_SESSION );
session.php
<?php
define( "DB_HOST", 'localhost' );
define( "DB_USER", '******' );
define( "DB_PWD", '******' );
define( "DB_NAME", '******' );
require_once('class/DatabaseSessionHandler.php');
// Use the DatabaseSessionHandler class to handle sessions
$session_handler = new DatabaseSessionHandler;
// Set up the handler above as the default session handler
session_set_save_handler(
array($session_handler, 'open'),
array($session_handler, 'close'),
array($session_handler, 'read'),
array($session_handler, 'write'),
array($session_handler, 'destroy'),
array($session_handler, 'gc')
);
DatabaseSessionHandler.php
<?php
class DatabaseSessionHandler
{
protected $connection;
protected $session_life_time;
public function __construct()
{
// Ensure that everything is closed correctly as
// per warning on http://uk3.php.net/session_set_save_handler
register_shutdown_function( 'session_write_close' );
}
public function open( $save_path, $session_name )
{
$this->connection = new mysqli( DB_HOST, DB_USER, DB_PWD, DB_NAME );
$this->session_life_time = get_cfg_var( "session.gc_maxlifetime" );
if ( $this->connection->connect_error )
return false;
return true;
}
public function close()
{
$this->connection->close();
return true;
}
public function read( $session_id )
{
$data = '';
$statement = $this->connection->prepare( "SELECT `session_data`
FROM `session`
WHERE `session_id` = ? " );
$statement->bind_param( "s", $session_id );
$statement->execute();
$statement->bind_result( $data );
return (string) $data;
}
public function write( $session_id, $session_data )
{
$expiry_time = time() + $this->session_life_time;
$statement = $this->connection->prepare( "REPLACE INTO `session`
(`session_id`, `session_data`,
`expiry_time`)
VALUES (?, ?, ?)" );
$statement->bind_param( "ssi", $session_id, $session_data, $expiry_time );
if ( !$statement->execute() )
return false;
return true;
}
public function destroy( $session_id )
{
$statement = $this->connection->prepare( "DELETE FROM `session`
WHERE `session_id` = ?" );
$statement->bind_param( "s", $session_id );
if ( !$statement->execute() )
return false;
return true;
}
public function gc( $max_lifetime )
{
$current_time = time();
$statement = $this->connection->prepare( "DELETE FROM `session`
WHERE `expiry_time` < ?" );
$statement->bind_param( "i", $current_time );
if ( !$statement->execute() )
return false;
return true;
}
}
