233 lines
5.7 KiB
PHP
233 lines
5.7 KiB
PHP
![]() |
<?php defined('SYSPATH') OR die('No direct access allowed.');
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/**
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* Process queuing/execution class. Allows an unlimited number of callbacks
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* to be added to 'events'. Events can be run multiple times, and can also
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* process event-specific data. By default, Kohana has several system events.
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*
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* $Id: Event.php 4679 2009-11-10 01:45:52Z isaiah $
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*
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* @package Core
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* @author Kohana Team
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* @copyright (c) 2007-2009 Kohana Team
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* @license http://kohanaphp.com/license
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* @link http://docs.kohanaphp.com/general/events
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*/
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abstract class Event_Core {
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// Event callbacks
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protected static $events = array();
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// Cache of events that have been run
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protected static $has_run = array();
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// Data that can be processed during events
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public static $data;
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/**
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* Add a callback to an event queue.
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*
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* @param string event name
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* @param array http://php.net/callback
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* @param boolean prevent duplicates
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* @return boolean
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*/
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public static function add($name, $callback, $unique = FALSE)
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{
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if ( ! isset(Event::$events[$name]))
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{
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// Create an empty event if it is not yet defined
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Event::$events[$name] = array();
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}
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elseif ($unique AND in_array($callback, Event::$events[$name], TRUE))
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{
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// The event already exists
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return FALSE;
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}
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// Add the event
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Event::$events[$name][] = $callback;
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return TRUE;
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}
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/**
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* Add a callback to an event queue, before a given event.
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*
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* @param string event name
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* @param array existing event callback
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* @param array event callback
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* @return boolean
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*/
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public static function add_before($name, $existing, $callback)
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{
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if (empty(Event::$events[$name]) OR ($key = array_search($existing, Event::$events[$name])) === FALSE)
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{
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// Just add the event if there are no events
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return Event::add($name, $callback);
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}
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else
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{
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// Insert the event immediately before the existing event
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return Event::insert_event($name, $key, $callback);
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}
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}
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/**
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* Add a callback to an event queue, after a given event.
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*
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* @param string event name
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* @param array existing event callback
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* @param array event callback
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* @return boolean
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*/
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public static function add_after($name, $existing, $callback)
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{
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if (empty(Event::$events[$name]) OR ($key = array_search($existing, Event::$events[$name])) === FALSE)
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{
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// Just add the event if there are no events
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return Event::add($name, $callback);
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}
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else
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{
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// Insert the event immediately after the existing event
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return Event::insert_event($name, $key + 1, $callback);
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}
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}
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/**
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* Inserts a new event at a specfic key location.
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*
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* @param string event name
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* @param integer key to insert new event at
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* @param array event callback
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* @return void
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*/
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private static function insert_event($name, $key, $callback)
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{
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if (in_array($callback, Event::$events[$name], TRUE))
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return FALSE;
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// Add the new event at the given key location
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Event::$events[$name] = array_merge
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(
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// Events before the key
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array_slice(Event::$events[$name], 0, $key),
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// New event callback
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array($callback),
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// Events after the key
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array_slice(Event::$events[$name], $key)
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);
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return TRUE;
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}
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/**
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* Replaces an event with another event.
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*
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* @param string event name
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* @param array event to replace
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* @param array new callback
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* @return boolean
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*/
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public static function replace($name, $existing, $callback)
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{
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if (empty(Event::$events[$name]) OR ($key = array_search($existing, Event::$events[$name], TRUE)) === FALSE)
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return FALSE;
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if ( ! in_array($callback, Event::$events[$name], TRUE))
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{
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// Replace the exisiting event with the new event
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Event::$events[$name][$key] = $callback;
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}
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else
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{
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// Remove the existing event from the queue
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unset(Event::$events[$name][$key]);
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// Reset the array so the keys are ordered properly
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Event::$events[$name] = array_values(Event::$events[$name]);
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}
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return TRUE;
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}
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/**
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* Get all callbacks for an event.
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*
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* @param string event name
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* @return array
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*/
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public static function get($name)
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{
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return empty(Event::$events[$name]) ? array() : Event::$events[$name];
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}
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/**
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* Clear some or all callbacks from an event.
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*
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* @param string event name
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* @param array specific callback to remove, FALSE for all callbacks
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* @return void
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*/
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public static function clear($name, $callback = FALSE)
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{
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if ($callback === FALSE)
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{
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Event::$events[$name] = array();
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}
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elseif (isset(Event::$events[$name]))
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{
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// Loop through each of the event callbacks and compare it to the
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// callback requested for removal. The callback is removed if it
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// matches.
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foreach (Event::$events[$name] as $i => $event_callback)
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{
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if ($callback === $event_callback)
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{
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unset(Event::$events[$name][$i]);
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}
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}
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}
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}
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/**
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* Execute all of the callbacks attached to an event.
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*
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* @param string event name
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* @param array data can be processed as Event::$data by the callbacks
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* @return void
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*/
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public static function run($name, & $data = NULL)
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{
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if ( ! empty(Event::$events[$name]))
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{
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// So callbacks can access Event::$data
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Event::$data =& $data;
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$callbacks = Event::get($name);
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foreach ($callbacks as $callback)
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{
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call_user_func_array($callback, array(&$data));
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}
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// Do this to prevent data from getting 'stuck'
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$clear_data = '';
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Event::$data =& $clear_data;
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}
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// The event has been run!
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Event::$has_run[$name] = $name;
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}
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/**
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* Check if a given event has been run.
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*
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* @param string event name
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* @return boolean
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*/
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public static function has_run($name)
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{
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return isset(Event::$has_run[$name]);
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}
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} // End Event
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