Events

The Forest City Labs Framework ships with a generic ListenerProvider that can be used in conjunction with any PSR-14 compliant event dispatcher (for example league/event).

To configure an event listener you can use the ForestCityLabs\Event\Attribute\EventListener attribute.

Creating an Event Listener

<?php

namespace Application\EventListener;

use ForestCityLabs\Framework\Attribute\EventListener;
use ForestCityLabs\Framework\Event\ListenerProvider;
use ForestCityLabs\Framework\Events\PreRouteDispatchEvent;

#[EventListener(PreRouteDispatchEvent::class, priority: ListenerProvider::PRIORITY_LATE)]
class PreRouteDispatchEventListener
{
    public function __invoke(PreRouteDispatchEvent $event) 
    {
        // ...do something with the event.
    }
}

The above example will listen for the pre route dispatch event and act later than most other events.

note

The available priorities for the listener are, in order:

• PRIORITY_FIRST
• PRIORITY_EARLY
• PRIORITY_NORMAL
• PRIORITY_LATE
• PRIORITY_LAST

Please note that there is no guarantee that first or last will be first or last, just earlier/later than events using the other constants.

Configuring an Event Dispatcher

To create an event dispatcher you first need to configure our listener provider.

warning

The example below uses the league event dispatcher, other event systems should work in a similar way, but there is no standard for how to wire a listener provider to a dispatcher.

<?php

use ForestCityLabs\Framework\Event\ListenerProvider;
use ForestCityLabs\Framework\Utility\ClassDiscovery\ScanDirectoryDiscovery;
use League\Event\EventDispatcher;
use Psr\Container\ContainerInterface;
use Psr\Cache\CacheItemPoolInterface;

$provider = new ListenerProvider(
    new ScanDirectoryDiscovery(__DIR__ . '/src/EventListener'),
    new CacheItemPoolInterface(), // Must be a concrete implementation.
    new ContainerInterface(), // Must be a concrete implementation.
);

// Now we can create the dispatcher.
$dispatcher = new EventDispatcher($provider);

// Dispatch an event.
$dispatcher->dispatch(new PreRouteDispatchEvent());

tip

To learn more about the ScanDirectoryDiscovery class and class discovery in general take a look at the class discovery documentation.