<?php
namespace CodeIgniter\Events;
use Config\Services;
/**
* CodeIgniter
*
* An open source application development framework for PHP
*
* This content is released under the MIT License (MIT)
*
* Copyright (c) 2014-2019 British Columbia Institute of Technology
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*
* @package CodeIgniter
* @author CodeIgniter Dev Team
* @copyright 2014-2019 British Columbia Institute of Technology (https://bcit.ca/)
* @license https://opensource.org/licenses/MIT MIT License
* @link https://codeigniter.com
* @since Version 3.0.0
* @filesource
*/
define('EVENT_PRIORITY_LOW', 200);
define('EVENT_PRIORITY_NORMAL', 100);
define('EVENT_PRIORITY_HIGH', 10);
/**
* Events
*/
class Events
{
/**
* The list of listeners.
*
* @var array
*/
protected static $listeners = [];
/**
* Flag to let us know if we've read from the Config file(s)
* and have all of the defined events.
*
* @var boolean
*/
protected static $initialized = false;
/**
* If true, events will not actually be fired.
* Useful during testing.
*
* @var boolean
*/
protected static $simulate = false;
/**
* Stores information about the events
* for display in the debug toolbar.
*
* @var array
*/
protected static $performanceLog = [];
/**
* A list of found files.
*
* @var array
*/
protected static $files = [];
//--------------------------------------------------------------------
/**
* Ensures that we have a events file ready.
*/
public static function initialize()
{
// Don't overwrite anything....
if (static::$initialized)
{
return;
}
$config = config('Modules');
$files = [APPPATH . 'Config/Events.php'];
if ($config->shouldDiscover('events'))
{
$locator = Services::locator();
$files = $locator->search('Config/Events.php');
}
static::$files = $files;
foreach (static::$files as $file)
{
if (is_file($file))
{
include $file;
}
}
static::$initialized = true;
}
//--------------------------------------------------------------------
/**
* Registers an action to happen on an event. The action can be any sort
* of callable:
*
* Events::on('create', 'myFunction'); // procedural function
* Events::on('create', ['myClass', 'myMethod']); // Class::method
* Events::on('create', [$myInstance, 'myMethod']); // Method on an existing instance
* Events::on('create', function() {}); // Closure
*
* @param $event_name
* @param callable $callback
* @param integer $priority
*/
public static function on($event_name, callable $callback, $priority = EVENT_PRIORITY_NORMAL)
{
if (! isset(static::$listeners[$event_name]))
{
static::$listeners[$event_name] = [
true, // If there's only 1 item, it's sorted.
[$priority],
[$callback],
];
}
else
{
static::$listeners[$event_name][0] = false; // Not sorted
static::$listeners[$event_name][1][] = $priority;
static::$listeners[$event_name][2][] = $callback;
}
}
//--------------------------------------------------------------------
/**
* Runs through all subscribed methods running them one at a time,
* until either:
* a) All subscribers have finished or
* b) a method returns false, at which point execution of subscribers stops.
*
* @param $eventName
* @param $arguments
*
* @return boolean
*/
public static function trigger($eventName, ...$arguments): bool
{
// Read in our Config/events file so that we have them all!
if (! static::$initialized)
{
static::initialize();
}
$listeners = static::listeners($eventName);
foreach ($listeners as $listener)
{
$start = microtime(true);
$result = static::$simulate === false ? $listener(...$arguments) : true;
if (CI_DEBUG)
{
static::$performanceLog[] = [
'start' => $start,
'end' => microtime(true),
'event' => strtolower($eventName),
];
}
if ($result === false)
{
return false;
}
}
return true;
}
//--------------------------------------------------------------------
/**
* Returns an array of listeners for a single event. They are
* sorted by priority.
*
* If the listener could not be found, returns FALSE, or TRUE if
* it was removed.
*
* @param $event_name
*
* @return array
*/
public static function listeners($event_name): array
{
if (! isset(static::$listeners[$event_name]))
{
return [];
}
// The list is not sorted
if (! static::$listeners[$event_name][0])
{
// Sort it!
array_multisort(static::$listeners[$event_name][1], SORT_NUMERIC, static::$listeners[$event_name][2]);
// Mark it as sorted already!
static::$listeners[$event_name][0] = true;
}
return static::$listeners[$event_name][2];
}
//--------------------------------------------------------------------
/**
* Removes a single listener from an event.
*
* If the listener couldn't be found, returns FALSE, else TRUE if
* it was removed.
*
* @param $event_name
* @param callable $listener
*
* @return boolean
*/
public static function removeListener($event_name, callable $listener): bool
{
if (! isset(static::$listeners[$event_name]))
{
return false;
}
foreach (static::$listeners[$event_name][2] as $index => $check)
{
if ($check === $listener)
{
unset(static::$listeners[$event_name][1][$index]);
unset(static::$listeners[$event_name][2][$index]);
return true;
}
}
return false;
}
//--------------------------------------------------------------------
/**
* Removes all listeners.
*
* If the event_name is specified, only listeners for that event will be
* removed, otherwise all listeners for all events are removed.
*
* @param null $event_name
*/
public static function removeAllListeners($event_name = null)
{
if (! is_null($event_name))
{
unset(static::$listeners[$event_name]);
}
else
{
static::$listeners = [];
}
}
//--------------------------------------------------------------------
/**
* Sets the path to the file that routes are read from.
*
* @param array $files
*/
public static function setFiles(array $files)
{
static::$files = $files;
}
//--------------------------------------------------------------------
/**
* Returns the files that were found/loaded during this request.
*
* @return mixed
*/
public function getFiles()
{
return static::$files;
}
//--------------------------------------------------------------------
/**
* Turns simulation on or off. When on, events will not be triggered,
* simply logged. Useful during testing when you don't actually want
* the tests to run.
*
* @param boolean $choice
*/
public static function simulate(bool $choice = true)
{
static::$simulate = $choice;
}
//--------------------------------------------------------------------
/**
* Getter for the performance log records.
*
* @return array
*/
public static function getPerformanceLogs()
{
return static::$performanceLog;
}
//--------------------------------------------------------------------
}
Jim Parry