interface State // Interface an welches sich die Konkreten Objekte halten muessen
{
	public function nextState ( Context $_context );
}
 
 
 
class On implements State // Konkretes Objekt 1
{
	public function nextState ( Context $_context )
	{
		$_context->setState(new Off());
		return 'turn Off ['.__METHOD__.']';
	}
}
 
 
 
class Off implements State // Konkretes Objekt 2
{
	public function nextState ( Context $_context )
	{
		$_context->setState(new On());
		return 'turn On ['.__METHOD__.']';
	}
}

class Context // Context zur Speicherung des aktuellen State's
{
	private $state = NULL;
 
	function __construct ( State $_state )
	{
		$this->setState($_state);
	}
 
 
	/**
	* Methode zum setzen eines neuen Status
	* @param State $_state : Uebergabe des neuen Konkreten Objekts
	*/
	public function setState ( State $_state )
	{
		$this->state = $_state;
	}
 
 
	/**
	* Weiterschalten zum naechsten State
	*/
	public function nextState ( )
	{
		return $this->state->nextState($this).'<br />';
	}
}
 

// Test
$cContext = new Context(new Off());
echo $cContext->nextState();
echo $cContext->nextState();
echo $cContext->nextState();
echo $cContext->nextState();
echo $cContext->nextState();

/**
Ausgabe
 
turn On [Off::nextState]
turn Off [On::nextState]
turn On [Off::nextState]
turn Off [On::nextState]
turn On [Off::nextState]
*/