note 68816 modified in language.oop5.patterns by danbrown
| From: | danbrown@php.net | Date: | Sun, 23 Jan 2011 16:43:23 +0000 |
| Subject: | note 68816 modified in language.oop5.patterns by danbrown | ||
| References: | 1 | Groups: | php.notes |
| Request: | Send a blank email to php-notes+get-176115@lists.php.net to get a copy of this message | ||
An easy way to have your singleton persistent between page loads:
<?php
/**
* Returns an instance of the singleton class.
* @return object The singleton instance
*/
public static function _instance()
{
// Start a session if not already started
Session::start();
if ( false == isset( $_SESSION[ self::$_singleton_class ] ) )
{
$class = self::$_singleton_class;
$_SESSION[ self::$_singleton_class ] = new $class;
}
return $_SESSION[ self::$_singleton_class ];
}
/**
* Destroy the singleton object. Deleting the session variable in the
* destructor does not make sense since the destructor is called every
* time the script ends.
*/
public static function _destroy()
{
$_SESSION[ self::$_singleton_class ] = null;
}
/**
* Initialize the singleton object. Use instead of constructor.
*/
public function _initialize( $name )
{
// Something...
}
/**
* Prevent cloning of singleton.
*/
private function __clone()
{
trigger_error( "Cloning a singleton object is not allowed.", E_USER_ERROR );
}
private static $_singleton_class = __CLASS__;
?>
--was--
An easy way to have your singleton persistent between page loads:
/**
* Returns an instance of the singleton class.
* @return object The singleton instance
*/
public static function _instance()
{
// Start a session if not already started
Session::start();
if ( false == isset( $_SESSION[ self::$_singleton_class ] ) )
{
$class = self::$_singleton_class;
$_SESSION[ self::$_singleton_class ] = new $class;
}
return $_SESSION[ self::$_singleton_class ];
}
/**
* Destroy the singleton object. Deleting the session variable in the
* destructor does not make sense since the destructor is called every
* time the script ends.
*/
public static function _destroy()
{
$_SESSION[ self::$_singleton_class ] = null;
}
/**
* Initialize the singleton object. Use instead of constructor.
*/
public function _initialize( $name )
{
// Something...
}
/**
* Prevent cloning of singleton.
*/
private function __clone()
{
trigger_error( "Cloning a singleton object is not allowed.", E_USER_ERROR );
}
private static $_singleton_class = __CLASS__;
http://php.net/manual/en/language.oop5.patterns.php