system/libraries/Event_Subject.php

   1 <?php defined('SYSPATH') OR die('No direct access allowed.');
   2 /**
   3  * Kohana event subject. Uses the SPL observer pattern.
   4  *
   5  * $Id: Event_Subject.php 3917 2009-01-21 03:06:22Z zombor $
   6  *
   7  * @package    Core
   8  * @author     Kohana Team
   9  * @copyright  (c) 2007-2008 Kohana Team
  10  * @license    http://kohanaphp.com/license.html
  11  */
  12 abstract class Event_Subject implements SplSubject {
  13
  14         // Attached subject listeners
  15         protected $listeners = array();
  16
  17         /**
  18          * Attach an observer to the object.
  19          *
  20          * @chainable
  21          * @param   object  Event_Observer
  22          * @return  object
  23          */
  24         public function attach(SplObserver $obj)
  25         {
  26                 if ( ! ($obj instanceof Event_Observer))
  27                         throw new Kohana_Exception('eventable.invalid_observer', get_class($obj), get_class($this));
  28
  29                 // Add a new listener
  30                 $this->listeners[spl_object_hash($obj)] = $obj;
  31
  32                 return $this;
  33         }
  34
  35         /**
  36          * Detach an observer from the object.
  37          *
  38          * @chainable
  39          * @param   object  Event_Observer
  40          * @return  object
  41          */
  42         public function detach(SplObserver $obj)
  43         {
  44                 // Remove the listener
  45                 unset($this->listeners[spl_object_hash($obj)]);
  46
  47                 return $this;
  48         }
  49
  50         /**
  51          * Notify all attached observers of a new message.
  52          *
  53          * @chainable
  54          * @param   mixed   message string, object, or array
  55          * @return  object
  56          */
  57         public function notify($message)
  58         {
  59                 foreach ($this->listeners as $obj)
  60                 {
  61                         $obj->notify($message);
  62                 }
  63
  64                 return $this;
  65         }
  66
  67 } // End Event Subject