事件系统¶

// In any configuration file or piece of code that executes before the event
use Cake\Event\EventManager;

EventManager::instance()->on(
    'Order.afterPlace',
    $aCallback
);

EventManager::instance()->setEventList(new EventList());

$eventsFired = EventManager::instance()->getEventList();
$firstEvent = $eventsFired[0];

use Cake\Event\EventManager;

EventManager::instance()->on('Server.terminate', function ($event) {
    // Perform tasks that should be done after the response has been
    // sent to the client.
});

use Cake\Event\EventManagerInterface;

public function events(EventManagerInterface $eventManager): EventManagerInterface
{
    $eventManager->on('Server.terminate', function ($event) {
        // Perform tasks that should be done after the response has been
        // sent to the client.
    });

    return $eventManager;
}

use Cake\Log\Log;

// From within a controller, or during application bootstrap.
$this->Orders->getEventManager()->on('Order.afterPlace', function ($event) {
    Log::write(
        'info',
        'A new order was placed with id: ' . $event->getSubject()->id
    );
});

$events = [
    'email-sending' => 'EmailSender::sendBuyEmail',
    'inventory' => [$this->InventoryManager, 'decrement'],
];
foreach ($events as $callable) {
    $eventManager->on('Order.afterPlace', $callable);
}

// You can create the following before the
// save operation, ie. config/bootstrap.php
use Cake\Datasource\FactoryLocator;
// If sending emails
use Cake\Mailer\Email;

FactoryLocator::get('Table')->get('ThirdPartyPlugin.Feedbacks')
    ->getEventManager()
    ->on('Model.afterSave', function($event, $entity)
    {
        // For example we can send an email to the admin
        $email = new Email('default');
        $email->setFrom(['[email protected]' => 'Your Site'])
            ->setTo('[email protected]')
            ->setSubject('New Feedback - Your Site')
            ->send('Body of message');
    });

// Attach listeners to EventManager.
$this->getEventManager()->on('User.Registration', [$this, 'userRegistration']);
$this->getEventManager()->on('User.Verification', [$this, 'userVerification']);
$this->getEventManager()->on('User.Authorization', [$this, 'userAuthorization']);

// Somewhere else in your application.
$events = $this->getEventManager()->matchingListeners('Verification');
if (!empty($events)) {
    // Perform logic related to presence of 'Verification' event listener.
    // For example removing the listener if present.
    $this->getEventManager()->off('User.Verification');
} else {
    // Perform logic related to absence of 'Verification' event listener
}

// Setting priority for a callback
$callback = [$this, 'doSomething'];
$this->getEventManager()->on(
    'Order.afterPlace',
    ['priority' => 2],
    $callback
);

// Setting priority for a listener
class UserStatistic implements EventListenerInterface
{
    public function implementedEvents()
    {
        return [
            'Order.afterPlace' => [
                'callable' => 'updateBuyStatistic',
                'priority' => 100
            ],
        ];
    }
}

$this->getEventManager()
    ->dispatch(new Event('View.afterRender', $this, ['view' => $viewFileName]));

function (EventInterface $event, $viewFileName)

public function doSomething($event)
{
    // ...
    return false; // Stops the event
}

public function updateBuyStatistic($event)
{
    // ...
    $event->stopPropagation();
}

public function place($order)
{
    $event = new Event('Order.beforePlace', $this, ['order' => $order]);
    $this->getEventManager()->dispatch($event);
    if ($event->isStopped()) {
        return false;
    }
    if ($this->Orders->save($order)) {
        // ...
    }
    // ...
}

// A listener callback
public function doSomething($event)
{
    // ...
    $alteredData = $event->getData('order') + $moreData;

    return $alteredData;
}

// Another listener callback
public function doSomethingElse($event)
{
    // ...
    $event->setResult(['order' => $alteredData] + $this->result());
}

// Using the event result
public function place($order)
{
    $event = new Event('Order.beforePlace', $this, ['order' => $order]);
    $this->getEventManager()->dispatch($event);
    if (!empty($event->getResult()['order'])) {
        $order = $event->getResult()['order'];
    }
    if ($this->Orders->save($order)) {
        // ...
    }
    // ...
}

// Attaching a function
$this->getEventManager()->on('My.event', [$this, 'doSomething']);

// Detaching the function
$this->getEventManager()->off('My.event', [$this, 'doSomething']);

// Attaching an anonymous function.
$myFunction = function ($event) { ... };
$this->getEventManager()->on('My.event', $myFunction);

// Detaching the anonymous function
$this->getEventManager()->off('My.event', $myFunction);

// Adding a EventListener
$listener = new MyEventLister();
$this->getEventManager()->on($listener);

// Detaching a single event key from a listener
$this->getEventManager()->off('My.event', $listener);

// Detaching all callbacks implemented by a listener
$this->getEventManager()->off($listener);