Protótipo classe para gerenciar sessão.

Session.php

<?php
namespace Yarkhan\SessionManager;

class Session{
	//The key on $_SESSION to store data
	static $sess_name = 'YarkhanSessionManager';
	private static $sess;

	static function isActive()
	{
		return !empty($_SESSION[self::$sess_name]['start_time']);
	}
	//start the session!
	static function start()
	{
		session_start();
		self::$sess =& $_SESSION[self::$sess_name];
		if(self::isActive())
		{
			self::$sess['last_update'] = time();
		}
		else {
			self::$sess['start_time'] = time();
			self::$sess['last_update'] = time();
		}
	}
	/**
	 * Return time() of when the session started
	 * @return [mixed] time() when session is active, or false
	 */
	static function start_time()
	{
		return self::isActive() ? self::$sess['start_time'] : false;
	}

	/**
	 * Return 
	 * @return mixed time() of the session last update, false if is not active
	 */
	static function last_update()
	{
		return self::isActive() ? self::$sess['last_update']:false;
	}
	/**
	 * Round house kick on session data
	 * @return void
	 */
	static function destroy()
	{
		if(!empty(self::$sess)) unset($_SESSION[self::$sess_name]);
	}

	/**
	 * setFlash. Data that is going to be destroyed the next time is read
	 * @param $key   
	 * @param $value 
	 * @return  void
	 */
	static function setFlash($key,$value)
	{
		if(!self::isActive()) return;
		self::$sess['_flash'][$key] = $value;
	}

	/**
	 * Get a flash value that has been stored. Data is destroyed unless
	 * $keep is set to true
	 * @param  str $key  key on flashdata
	 * @param  boolean $keep if data should be destroyed after reading
	 * @return mixed Value stored in flashdata $key or false if session is not
	 * active or $key hasn't been defined
	 */
	static function getFlash($key,$keep = false)
	{
		if(!self::isActive() or empty(self::$sess['_flash'][$key])) return false;

		$flash = self::$sess['_flash'][$key];
		if(!$keep) unset(self::$sess['_flash'][$key]);
		return $flash;
	}
	/**
	 * Data that will be stored until the session ends
	 * @param str $key   key on userdata
	 * @param mixed $value value on userdata
	 */
	static function setUserdata($key,$value)
	{
		if(!self::isActive()) return;
		self::$sess['_userdata'][$key] = $value;
	}
	/**
	 * Get data stored on userdata
	 * @param  str $key $key on userdata
	 * @return mixed 	return value of $key in userdata. False
	 * if session is not active or $key is not set.
	 */
	static function getUserdata($key)
	{
		if(!self::isActive()) return;
		if(!empty(self::$sess['_userdata'][$key]))
		{ 
			return self::$sess['_userdata'][$key];
		}
	}
}