Civi/Core/Event/ServiceListener.php

   1 <?php
   2
   3 namespace Civi\Core\Event;
   4
   5 /**
   6  * A ServiceListener is a `callable` (supporting "__invoke()") which references
   7  * a method of a service-object.
   8  *
   9  * The following two callables are conceptually similar:
  10  *
  11  *   (A) addListener('some.event', [Civi::service('foo'), 'doBar']);
  12  *   (B) addListener('some.event', new ServiceListener(['foo', 'doBar']));
  13  *
  14  * The difference is that (A) immediately instantiates the 'foo' service,
  15  * whereas (B) instantiates `foo` lazily. (B) is more amenable to serialization,
  16  * caching, etc. If you have a long-tail of many services/listeners/etc that
  17  * are not required for every page-load, then (B) should perform better.
  18  *
  19  * @package Civi\Core\Event
  20  */
  21 class ServiceListener {
  22
  23   /**
  24    * @var array
  25    *   Ex: ['service_name', 'someMethod']
  26    */
  27   private $inertCb = NULL;
  28
  29   /**
  30    * @var array|null
  31    *   Ex: [$svcObj, 'someMethod']
  32    */
  33   private $liveCb = NULL;
  34
  35   /**
  36    * @var \Symfony\Component\DependencyInjection\ContainerInterface
  37    */
  38   private $container = NULL;
  39
  40   /**
  41    * @param array $callback
  42    *   Ex: ['service_name', 'someMethod']
  43    */
  44   public function __construct($callback) {
  45     $this->inertCb = $callback;
  46   }
  47
  48   public function __invoke(...$args) {
  49     if ($this->liveCb === NULL) {
  50       $c = $this->container ?: \Civi::container();
  51       $this->liveCb = [$c->get($this->inertCb[0]), $this->inertCb[1]];
  52     }
  53     return call_user_func_array($this->liveCb, $args);
  54   }
  55
  56   public function __toString() {
  57     $class = NULL;
  58     if (\Civi\Core\Container::isContainerBooted()) {
  59       try {
  60         $c = $this->container ?: \Civi::container();
  61         $class = $c->findDefinition($this->inertCb[0])->getClass();
  62       }
  63       catch (Throwable $t) {
  64       }
  65     }
  66     if ($class) {
  67       return sprintf('$(%s)->%s($e) [%s]', $this->inertCb[0], $this->inertCb[1], $class);
  68     }
  69     else {
  70       return sprintf('\$(%s)->%s($e)', $this->inertCb[0], $this->inertCb[1]);
  71     }
  72   }
  73
  74   public function __sleep() {
  75     return ['inertCb'];
  76   }
  77
  78   /**
  79    * @param \Symfony\Component\DependencyInjection\ContainerInterface $container
  80    * @return static
  81    */
  82   public function setContainer(\Symfony\Component\DependencyInjection\ContainerInterface $container) {
  83     $this->container = $container;
  84     return $this;
  85   }
  86
  87 }