<?php
/**
* Zend Framework (http://framework.zend.com/)
*
* @link http://github.com/zendframework/zf2 for the canonical source repository
* @copyright Copyright (c) 2005-2014 Zend Technologies USA Inc. (http://www.zend.com)
* @license http://framework.zend.com/license/new-bsd New BSD License
*/
namespace Zend\EventManager;
use Zend\Stdlib\CallbackHandler;
use Zend\Stdlib\PriorityQueue;
/**
* Shared/contextual EventManager
*
* Allows attaching to EMs composed by other classes without having an instance first.
* The assumption is that the SharedEventManager will be injected into EventManager
* instances, and then queried for additional listeners when triggering an event.
*/
class SharedEventManager implements
SharedEventAggregateAwareInterface,
SharedEventManagerInterface
{
/**
* Identifiers with event connections
* @var array
*/
protected $identifiers = array();
/**
* Attach a listener to an event
*
* Allows attaching a callback to an event offered by one or more
* identifying components. As an example, the following connects to the
* "getAll" event of both an AbstractResource and EntityResource:
*
* <code>
* $sharedEventManager = new SharedEventManager();
* $sharedEventManager->attach(
* array('My\Resource\AbstractResource', 'My\Resource\EntityResource'),
* 'getAll',
* function ($e) use ($cache) {
* if (!$id = $e->getParam('id', false)) {
* return;
* }
* if (!$data = $cache->load(get_class($resource) . '::getOne::' . $id )) {
* return;
* }
* return $data;
* }
* );
* </code>
*
* @param string|array $id Identifier(s) for event emitting component(s)
* @param string $event
* @param callable $callback PHP Callback
* @param int $priority Priority at which listener should execute
* @return CallbackHandler|array Either CallbackHandler or array of CallbackHandlers
*/
public function attach($id, $event, $callback, $priority = 1)
{
$ids = (array) $id;
$listeners = array();
foreach ($ids as $id) {
if (!array_key_exists($id, $this->identifiers)) {
$this->identifiers[$id] = new EventManager($id);
}
$listeners[] = $this->identifiers[$id]->attach($event, $callback, $priority);
}
if (count($listeners) > 1) {
return $listeners;
}
return $listeners[0];
}
/**
* Attach a listener aggregate
*
* Listener aggregates accept an EventManagerInterface instance, and call attachShared()
* one or more times, typically to attach to multiple events using local
* methods.
*
* @param SharedListenerAggregateInterface $aggregate
* @param int $priority If provided, a suggested priority for the aggregate to use
* @return mixed return value of {@link ListenerAggregateInterface::attachShared()}
*/
public function attachAggregate(SharedListenerAggregateInterface $aggregate, $priority = 1)
{
return $aggregate->attachShared($this, $priority);
}
/**
* Detach a listener from an event offered by a given resource
*
* @param string|int $id
* @param CallbackHandler $listener
* @return bool Returns true if event and listener found, and unsubscribed; returns false if either event or listener not found
*/
public function detach($id, CallbackHandler $listener)
{
if (!array_key_exists($id, $this->identifiers)) {
return false;
}
return $this->identifiers[$id]->detach($listener);
}
/**
* Detach a listener aggregate
*
* Listener aggregates accept an SharedEventManagerInterface instance, and call detachShared()
* of all previously attached listeners.
*
* @param SharedListenerAggregateInterface $aggregate
* @return mixed return value of {@link SharedListenerAggregateInterface::detachShared()}
*/
public function detachAggregate(SharedListenerAggregateInterface $aggregate)
{
return $aggregate->detachShared($this);
}
/**
* Retrieve all registered events for a given resource
*
* @param string|int $id
* @return array
*/
public function getEvents($id)
{
if (!array_key_exists($id, $this->identifiers)) {
//Check if there are any id wildcards listeners
if ('*' != $id && array_key_exists('*', $this->identifiers)) {
return $this->identifiers['*']->getEvents();
}
return false;
}
return $this->identifiers[$id]->getEvents();
}
/**
* Retrieve all listeners for a given identifier and event
*
* @param string|int $id
* @param string|int $event
* @return false|PriorityQueue
*/
public function getListeners($id, $event)
{
if (!array_key_exists($id, $this->identifiers)) {
return false;
}
return $this->identifiers[$id]->getListeners($event);
}
/**
* Clear all listeners for a given identifier, optionally for a specific event
*
* @param string|int $id
* @param null|string $event
* @return bool
*/
public function clearListeners($id, $event = null)
{
if (!array_key_exists($id, $this->identifiers)) {
return false;
}
if (null === $event) {
unset($this->identifiers[$id]);
return true;
}
return $this->identifiers[$id]->clearListeners($event);
}
}