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authorBharat Mediratta <bharat@menalto.com>2009-05-27 15:11:53 -0700
committerBharat Mediratta <bharat@menalto.com>2009-05-27 15:11:53 -0700
commit12fe58d997d2066dc362fd393a18b4e5da190513 (patch)
tree3ad8e5afb77829e1541ec96d86785760d65c04ac /system/core/Event.php
parent00f47d4ddddcd1902db817018dd79ac01bcc8e82 (diff)
Rename 'kohana' to 'system' to conform to the Kohana filesystem layout. I'm comfortable with us not clearly drawing the distinction about the fact that it's Kohana.
Diffstat (limited to 'system/core/Event.php')
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diff --git a/system/core/Event.php b/system/core/Event.php
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+<?php defined('SYSPATH') OR die('No direct access allowed.');
+/**
+ * Process queuing/execution class. Allows an unlimited number of callbacks
+ * to be added to 'events'. Events can be run multiple times, and can also
+ * process event-specific data. By default, Kohana has several system events.
+ *
+ * $Id: Event.php 3993 2009-02-17 18:42:50Z jheathco $
+ *
+ * @package Core
+ * @author Kohana Team
+ * @copyright (c) 2007 Kohana Team
+ * @license http://kohanaphp.com/license.html
+ * @link http://docs.kohanaphp.com/general/events
+ */
+final class Event {
+
+ // Event callbacks
+ private static $events = array();
+
+ // Cache of events that have been run
+ private static $has_run = array();
+
+ // Data that can be processed during events
+ public static $data;
+
+ /**
+ * Add a callback to an event queue.
+ *
+ * @param string event name
+ * @param array http://php.net/callback
+ * @return boolean
+ */
+ public static function add($name, $callback)
+ {
+ if ( ! isset(self::$events[$name]))
+ {
+ // Create an empty event if it is not yet defined
+ self::$events[$name] = array();
+ }
+ elseif (in_array($callback, self::$events[$name], TRUE))
+ {
+ // The event already exists
+ return FALSE;
+ }
+
+ // Add the event
+ self::$events[$name][] = $callback;
+
+ return TRUE;
+ }
+
+ /**
+ * Add a callback to an event queue, before a given event.
+ *
+ * @param string event name
+ * @param array existing event callback
+ * @param array event callback
+ * @return boolean
+ */
+ public static function add_before($name, $existing, $callback)
+ {
+ if (empty(self::$events[$name]) OR ($key = array_search($existing, self::$events[$name])) === FALSE)
+ {
+ // Just add the event if there are no events
+ return self::add($name, $callback);
+ }
+ else
+ {
+ // Insert the event immediately before the existing event
+ return self::insert_event($name, $key, $callback);
+ }
+ }
+
+ /**
+ * Add a callback to an event queue, after a given event.
+ *
+ * @param string event name
+ * @param array existing event callback
+ * @param array event callback
+ * @return boolean
+ */
+ public static function add_after($name, $existing, $callback)
+ {
+ if (empty(self::$events[$name]) OR ($key = array_search($existing, self::$events[$name])) === FALSE)
+ {
+ // Just add the event if there are no events
+ return self::add($name, $callback);
+ }
+ else
+ {
+ // Insert the event immediately after the existing event
+ return self::insert_event($name, $key + 1, $callback);
+ }
+ }
+
+ /**
+ * Inserts a new event at a specfic key location.
+ *
+ * @param string event name
+ * @param integer key to insert new event at
+ * @param array event callback
+ * @return void
+ */
+ private static function insert_event($name, $key, $callback)
+ {
+ if (in_array($callback, self::$events[$name], TRUE))
+ return FALSE;
+
+ // Add the new event at the given key location
+ self::$events[$name] = array_merge
+ (
+ // Events before the key
+ array_slice(self::$events[$name], 0, $key),
+ // New event callback
+ array($callback),
+ // Events after the key
+ array_slice(self::$events[$name], $key)
+ );
+
+ return TRUE;
+ }
+
+ /**
+ * Replaces an event with another event.
+ *
+ * @param string event name
+ * @param array event to replace
+ * @param array new callback
+ * @return boolean
+ */
+ public static function replace($name, $existing, $callback)
+ {
+ if (empty(self::$events[$name]) OR ($key = array_search($existing, self::$events[$name], TRUE)) === FALSE)
+ return FALSE;
+
+ if ( ! in_array($callback, self::$events[$name], TRUE))
+ {
+ // Replace the exisiting event with the new event
+ self::$events[$name][$key] = $callback;
+ }
+ else
+ {
+ // Remove the existing event from the queue
+ unset(self::$events[$name][$key]);
+
+ // Reset the array so the keys are ordered properly
+ self::$events[$name] = array_values(self::$events[$name]);
+ }
+
+ return TRUE;
+ }
+
+ /**
+ * Get all callbacks for an event.
+ *
+ * @param string event name
+ * @return array
+ */
+ public static function get($name)
+ {
+ return empty(self::$events[$name]) ? array() : self::$events[$name];
+ }
+
+ /**
+ * Clear some or all callbacks from an event.
+ *
+ * @param string event name
+ * @param array specific callback to remove, FALSE for all callbacks
+ * @return void
+ */
+ public static function clear($name, $callback = FALSE)
+ {
+ if ($callback === FALSE)
+ {
+ self::$events[$name] = array();
+ }
+ elseif (isset(self::$events[$name]))
+ {
+ // Loop through each of the event callbacks and compare it to the
+ // callback requested for removal. The callback is removed if it
+ // matches.
+ foreach (self::$events[$name] as $i => $event_callback)
+ {
+ if ($callback === $event_callback)
+ {
+ unset(self::$events[$name][$i]);
+ }
+ }
+ }
+ }
+
+ /**
+ * Execute all of the callbacks attached to an event.
+ *
+ * @param string event name
+ * @param array data can be processed as Event::$data by the callbacks
+ * @return void
+ */
+ public static function run($name, & $data = NULL)
+ {
+ if ( ! empty(self::$events[$name]))
+ {
+ // So callbacks can access Event::$data
+ self::$data =& $data;
+ $callbacks = self::get($name);
+
+ foreach ($callbacks as $callback)
+ {
+ call_user_func($callback);
+ }
+
+ // Do this to prevent data from getting 'stuck'
+ $clear_data = '';
+ self::$data =& $clear_data;
+ }
+
+ // The event has been run!
+ self::$has_run[$name] = $name;
+ }
+
+ /**
+ * Check if a given event has been run.
+ *
+ * @param string event name
+ * @return boolean
+ */
+ public static function has_run($name)
+ {
+ return isset(self::$has_run[$name]);
+ }
+
+} // End Event \ No newline at end of file