PhpRiot
Become Zend Certified

Prepare for the ZCE exam using our quizzes (web or iPad/iPhone). More info...


When you're ready get 7.5% off your exam voucher using voucher CJQNOV23 at the Zend Store

The SessionHandlerInterface class

(PHP 5 >= 5.4.0)

Introduction

SessionHandlerInterface is an interface which defines a prototype for creating a custom session handler. In order to pass a custom session handler to session_set_save_handler() using its OOP invocation, the class must implement this interface.

Please note the callback methods of this class are designed to be called internally by PHP and are not meant to be called from user-space code.

Class synopsis

SessionHandlerInterface {
/* Methods */
abstract public bool close ( void )
abstract public bool destroy ( string $session_id )
abstract public bool gc ( string $maxlifetime )
abstract public bool open ( string $save_path , string $name )
abstract public string read ( string $session_id )
abstract public bool write ( string $session_id , string $session_data )
}

Example #1 Example using SessionHandlerInterface

The following example provides file based session storage similar to the PHP sessions default save handler files. This example could easily be extended to cover database storage using your favorite PHP supported database engine.

Note we use the OOP prototype with session_set_save_handler() and register the shutdown function using the function's parameter flag. This is generally advised when registering objects as session save handlers.

<?php
class MySessionHandler implements SessionHandlerInterface
{
    private 
$savePath;

    public function 
open($savePath$sessionName)
    {
        
$this->savePath $savePath;
        if (!
is_dir($this->savePath)) {
            
mkdir($this->savePath0777);
        }

        return 
true;
    }

    public function 
close()
    {
        return 
true;
    }

    public function 
read($id)
    {
        return (string)@
file_get_contents("$this->savePath/sess_$id");
    }

    public function 
write($id$data)
    {
        return 
file_put_contents("$this->savePath/sess_$id"$data) === false false true;
    }

    public function 
destroy($id)
    {
        
$file "$this->savePath/sess_$id";
        if (
file_exists($file)) {
            
unlink($file);
        }

        return 
true;
    }

    public function 
gc($maxlifetime)
    {
        foreach (
glob("$this->savePath/sess_*") as $file) {
            if (
filemtime($file) + $maxlifetime time() && file_exists($file)) {
                
unlink($file);
            }
        }

        return 
true;
    }
}

$handler = new MySessionHandler();
session_set_save_handler($handlertrue);
session_start();

// proceed to set and retrieve values by key from $_SESSION

Table of Contents

PHP Manual