Neat Event components provide a clean and expressive API for your application to dispatch and listen for events. The Neat Event components implement the PSR-14 interfaces for optimal interoperability.
NOTE: Event listeners are required to have their first parameter named '$event'.
To install this package, simply issue composer on the command line:
composer require neat/event
The event dispatcher can be created with a few lines of code.
<?php
// First create your container (used for event dispatching and dependency injection)
$container = new Neat\Service\Container();
// The dispatcher will need a service container for dependency injection
$dispatcher = new Neat\Event\Dispatcher($container);<?php
// A generic event can be defined using a simple PHP class without any members
class SomeEvent
{
}
// Specific events may also use inheritance using extends or interfaces
class SomeSpecificEvent extends SomeEvent
{
}
// Implement the Stoppable event interface if you want control over dispatching your event
class SomeStoppableEvent implements Neat\Event\Stoppable
{
public function isPropagationStopped(): bool
{
return random_int(0, 1) == 1;
}
}Your event lister can be any callable function or method as long as it has
an $event parameter that accepts the event object we're listening for.
<?php
// Now listen for events of this class or any of its subclasses or implementations
$dispatcher->listen(SomeEvent::class, function (SomeEvent $event) {
// ...
});
// Or for a specific event
$dispatcher->listen(SomeSpecificEvent::class, function (SomeSpecificEvent $event) {
// ...
});Now we're ready to dispatch an event
<?php
// This will trigger only the SomeEvent listener, NOT the SomeSpecificEvent listener
$dispatcher->dispatch(new SomeEvent());
// This will trigger both the SomeEvent and SomeSpecificEvent listeners
$dispatcher->dispatch(new SomeSpecificEvent());