src/Pho/Lib/Graph/Event/EmitterTrait.php
<?php declare (strict_types=1);
namespace Pho\Lib\Graph\Event;
/**
* Event Emitter Trait
*
* This trait contains all the basic functions to implement an
* EventEmitterInterface.
*
* Using the trait + interface allows you to add EventEmitter capabilities
* without having to change your base-class.
*
* Please note, this is a slightly modified version of Sabre/Event
* to fit with Pho-Lib-Graph's needs.
*
* @copyright Copyright (C) fruux GmbH (https://fruux.com/)
* @author Evert Pot (http://evertpot.com/)
* @author Emre Sokullu <emre@phonetworks.org>
* @license http://sabre.io/license/ Modified BSD License
*/
trait EmitterTrait {
/**
* The list of listeners
*
* @var array
*/
protected $listeners = [];
protected $listeners_flat = [];
/**
* Subscribe to an event.
*
* @return void
*/
function on(string $eventName, /*mixed*/ $callBack, int $priority = 100)
{
if(!is_callable($callBack)) {
error_log("callback is not callable");
}
if(is_array($callBack)) {
foreach($this->listeners($eventName, true) as $listener) {
if(is_object($listener) && $listener instanceof \Closure)
continue;
if($listener[1]==$callBack[1]) {
if(is_object($listener[0])) {
if($listener[0]->id()->equals($callBack[0]->id()))
return;
}
if($listener[0]==$callBack[0]->id()->toString())
return;
}
}
}
$closure = \Closure::fromCallable($callBack);
// $analyzer = new \SuperClosure\Analyzer\TokenAnalyzer();
// eval(\Psy\sh());
if (!isset($this->listeners[$eventName])) {
$this->listeners[$eventName] = [
true, // If there's only one item, it's sorted
[$priority],
[$closure]
];
if(is_array($callBack)) {
//$subject=$analyzer->analyze($closure);
$this->listeners_flat[$eventName] = [
true, // If there's only one item, it's sorted
[$priority],
[
[
$callBack[0]->id()->toString(), // $subject["reflection"]->getClosureThis()->id()->toString(),
$callBack[1]
]
]
];
}
} else {
$this->listeners[$eventName][0] = false; // marked as unsorted
$this->listeners[$eventName][1][] = $priority;
$this->listeners[$eventName][2][] = $closure;
if(is_array($callBack)) {
//$subject=$analyzer->analyze($closure);
$this->listeners_flat[$eventName][0] = false;
$this->listeners_flat[$eventName][1][] = $priority;
$this->listeners_flat[$eventName][2][] = [
$callBack[0]->id()->toString(), //$subject["reflection"]->getClosureThis()->id()->toString(),
$callBack[1]
];
}
}
}
/**
* Emits an event.
*
* This method will return true if 0 or more listeners were succesfully
* handled. false is returned if one of the events broke the event chain.
*
* **Pho: Please note, continueCallback does not exist with Pho**
*
* If the continueCallBack is specified, this callback will be called every
* time before the next event handler is called.
*
* If the continueCallback returns false, event propagation stops. This
* allows you to use the eventEmitter as a means for listeners to implement
* functionality in your application, and break the event loop as soon as
* some condition is fulfilled.
*
* Note that returning false from an event subscriber breaks propagation
* and returns false, but if the continue-callback stops propagation, this
* is still considered a 'successful' operation and returns true.
*
* Lastly, if there are 5 event handlers for an event. The continueCallback
* will be called at most 4 times.
*/
function emit(string $eventName, array $arguments = []) : bool {
foreach ($this->listeners($eventName) as $listener) {
$result = \call_user_func_array($listener, $arguments);
if ($result === false) {
return false;
}
}
return true;
}
/**
* Returns the list of listeners for an event.
*
* The list is returned as an array, and the list of events are sorted by
* their priority.
*
* @return callable[]
*/
function listeners(string $eventName, bool $flat=false) : array {
if (!isset($this->listeners[$eventName])) {
return [];
}
// The list is not sorted
if (!$this->listeners[$eventName][0]) {
// Sorting
\array_multisort($this->listeners[$eventName][1], SORT_NUMERIC, $this->listeners[$eventName][2]);
\array_multisort($this->listeners_flat[$eventName][1], SORT_NUMERIC, $this->listeners_flat[$eventName][2]);
// Marking the listeners as sorted
$this->listeners[$eventName][0] = true;
$this->listeners_flat[$eventName][0] = true;
}
if(!$flat)
return $this->listeners[$eventName][2];
else
return $this->listeners_flat[$eventName][2];
}
/**
* Removes all listeners.
*
* If the eventName argument is specified, all listeners for that event are
* removed. If it is not specified, every listener for every event is
* removed.
*
* @return void
*/
function removeAllListeners(string $eventName = null) {
if (!\is_null($eventName)) {
unset($this->listeners[$eventName]);
unset($this->listeners_flat[$eventName]);
} else {
$this->listeners = [];
$this->listeners_flat = [];
}
}
}