1 <?php

     2 

     3 /*

     4  * This file is part of the Symfony package.

     5  *

     6  * (c) Fabien Potencier <fabien@symfony.com>

     7  *

     8  * For the full copyright and license information, please view the LICENSE

     9  * file that was distributed with this source code.

    10  */

    11 

    12 namespace Symfony\Bundle\FrameworkBundle;

    13 

    14 use Symfony\Component\DependencyInjection\ContainerInterface;

    15 use Symfony\Component\EventDispatcher\EventDispatcher;

    16 use Symfony\Component\EventDispatcher\Event;

    17 

    18 /**

    19  * Lazily loads listeners and subscribers from the dependency injection

    20  * container

    21  *

    22  * @author Fabien Potencier <fabien@symfony.com>

    23  * @author Bernhard Schussek <bernhard.schussek@symfony.com>

    24  */

    25 class ContainerAwareEventDispatcher extends EventDispatcher

    26 {

    27     /**

    28      * The container from where services are loaded

    29      * @var ContainerInterface

    30      */

    31     private $container;

    32 

    33     /**

    34      * The service IDs of the event listeners and subscribers

    35      * @var array

    36      */

    37     private $listenerIds = array();

    38 

    39     /**

    40      * The services registered as listeners

    41      * @var array

    42      */

    43     private $listeners = array();

    44 

    45     /**

    46      * Constructor.

    47      *

    48      * @param ContainerInterface $container A ContainerInterface instance

    49      */

    50     public function __construct(ContainerInterface $container)

    51     {

    52         $this->container = $container;

    53     }

    54 

    55     /**

    56      * Adds a service as event listener

    57      *

    58      * @param string   $eventName Event for which the listener is added

    59      * @param array    $callback  The service ID of the listener service & the method

    60      *                            name that has to be called

    61      * @param integer  $priority  The higher this value, the earlier an event listener

    62      *                            will be triggered in the chain.

    63      *                            Defaults to 0.

    64      */

    65     public function addListenerService($eventName, $callback, $priority = 0)

    66     {

    67         if (!is_array($callback) || 2 !== count($callback)) {

    68             throw new \InvalidArgumentException('Expected an array("service", "method") argument');

    69         }

    70 

    71         $this->listenerIds[$eventName][] = array($callback[0], $callback[1], $priority);

    72     }

    73 

    74     /**

    75      * {@inheritDoc}

    76      *

    77      * Lazily loads listeners for this event from the dependency injection

    78      * container.

    79      *

    80      * @throws \InvalidArgumentException if the service is not defined

    81      */

    82     public function dispatch($eventName, Event $event = null)

    83     {

    84         if (isset($this->listenerIds[$eventName])) {

    85             foreach ($this->listenerIds[$eventName] as $args) {

    86                 list($serviceId, $method, $priority) = $args;

    87                 $listener = $this->container->get($serviceId);

    88 

    89                 $key = $serviceId.'.'.$method;

    90                 if (!isset($this->listeners[$eventName][$key])) {

    91                     $this->addListener($eventName, array($listener, $method), $priority);

    92                 } elseif ($listener !== $this->listeners[$eventName][$key]) {

    93                     $this->removeListener($eventName, array($this->listeners[$eventName][$key], $method));

    94                     $this->addListener($eventName, array($listener, $method), $priority);

    95                 }

    96 

    97                 $this->listeners[$eventName][$key] = $listener;

    98             }

    99         }

   100 

   101         parent::dispatch($eventName, $event);

   102     }

   103 }