/**
* Trigger an event
*
* @param string $eventName
* @param mixed $origin
* @param mixed $context
*
* @param EventInterface $event
* @return EventInterface
* @throws Exception
* @throws \ObjectivePHP\Primitives\Exception
* @throws \ObjectivePHP\ServicesFactory\Exception\ServiceNotFoundException
*/
public function trigger($eventName, $origin = null, $context = [], EventInterface $event = null)
{
if (is_null($origin)) {
$origin = $this;
}
// cast context to Collection
$context = Collection::cast($context);
// cannot get event from factory
// because of injection process
// which triggers an event causing
// an infinite loop...
if (is_null($event)) {
$event = new Event();
}
$event->setName($eventName)->setOrigin($origin)->setContext($context);
// add reference to previous event if any
if ($previous = \current($this->currentEventsQueue)) {
$event->setPrevious($previous);
}
$this->currentEventsQueue[(string) $event->getName()] = $event;
$listeners = $this->getListeners($eventName);
// TODO sort listeners according to their priority or other mechanism
$i = 0;
foreach ($listeners as $listenersGroup) {
$callbacks = [];
// handle callbacks aggregate
foreach ($listenersGroup as $alias => $callback) {
if ($callback instanceof CallbacksAggregate) {
$callback->getCallbacks()->each(function ($callback, $callbackAlias) use(&$callbacks, $alias) {
$callbackAlias = implode('.', [$alias, $callbackAlias]);
$callbacks[$callbackAlias] = $callback;
});
} else {
$callbacks[$alias] = $callback;
}
}
foreach ($callbacks as $alias => $callback) {
// handle service references
if ($callback instanceof ServiceReference) {
$callback = $this->getServicesFactory()->get($callback->getId());
}
// if listener is a class name, instantiate it
if (!is_callable($callback) && class_exists($callback)) {
$className = $callback;
$callback = new $className();
if (!is_callable($callback)) {
throw new Exception(sprintf('Class "%s" does not implement __invoke(), thus cannot be used as a callback', $className), Exception::EVENT_INVALID_CALLBACK);
}
}
$result = $callback($event);
// gather exceptions
if ($result instanceof \Exception) {
$event->setException($i, $result);
}
$event->setResult(is_string($alias) ? $alias : $i, $result);
if ($event->isHalted()) {
// yes, this is a goto...
// I know that it was not absolutely needed, but it's a quite long story
// so please keep it as is.
// ping @EmmanuelJacoby :)
//
// @gdelamarre
goto shunt;
}
if (!is_string($alias)) {
$i++;
}
}
}
// target reached from within the triggering loop
// if the event was halted by a listener
shunt:
// event has been triggered, it is now removed from events queue
array_pop($this->currentEventsQueue);
end($this->currentEventsQueue);
return $event;
}
