EventDispatcher

EventDispatcher Class.

Manages the registration and dispatching of events throughout the application. This class follows the Singleton pattern to ensure a single instance manages all events. Listeners are registered based on the type hint of the first parameter of their handle method.

Example Usage:

// Define an event
class UserLoggedInEvent {
    use Hazaar\Events\Dispatchable;
    public $userId;
    public function __construct(int $userId) { $this->userId = $userId; }
}

// Define a listener
class UserLoginListener {
    public function handle(UserLoggedInEvent $event) {
        echo "User logged in: " . $event->userId;
    }
}

// Get the singleton instance
$dispatcher = EventDispatcher::getInstance();

// Add the listener
$dispatcher->addListener(new UserLoginListener());

// Dispatch the event using the Dispatchable trait
UserLoggedInEvent::dispatch(123); // Output: User logged in: 123

Properties

instance

public EventDispatcher $instance

listeners

private array $listeners

dispatchQueue

private array $dispatchQueue

Methods

__construct

Private constructor to prevent direct instantiation.

private __construct(): void

Use getInstance() to get the singleton instance.

__clone

Private clone method to prevent cloning of the singleton instance.

private __clone(): void

getInstance

Gets the singleton instance of the EventDispatcher.

public getInstance(): EventDispatcher

Ensures that only one instance of the EventDispatcher exists. If an instance does not exist, it creates one.

withEvents

Scans a directory for listener classes, instantiates them, and adds them.

public withEvents(string $listenerDir): void

Assumes listener classes are in the 'App\Listener' namespace and filenames match class names.

Parameters

Parameter	Type	Description
$listenerDir	string	the directory path containing listener class files

addListener

Adds an event listener object to the dispatcher.

public addListener(object $listener): bool

The listener is registered based on the type hint of the first parameter of its handle method. The listener object must have a public handle method.

Parameters

Parameter	Type	Description
$listener	object	the listener object to add

listen

Registers a listener class for a specific event class name.

public listen(string $event, string $listener): void

This method is less type-safe than addListener as it relies on string class names. It's generally recommended to use addListener with instantiated objects.

Parameters

Parameter	Type	Description
$event	string	the fully qualified class name of the event
$listener	string	the fully qualified class name of the listener

getListeners

Retrieves all registered listener objects for a given event class name.

public getListeners(string $event): void

Parameters

Parameter	Type	Description
$event	string	the fully qualified class name of the event

clearListeners

Removes all registered listeners from the dispatcher.

public clearListeners(): void

dispatch

Dispatches an event object to all registered listeners.

public dispatch(object $event): void

Finds listeners registered for the specific class of the event object. If a listener implements the Queuable interface, the event is added to a queue for later processing via dispatchQueue(). Otherwise, the listener's handle method is called immediately with the event object.

Parameters

Parameter	Type	Description
$event	object	the event object to dispatch

dispatchQueue

Dispatches all events currently held in the queue.

public dispatchQueue(?string $eventName): void

Iterates through the queued events and calls the handle method of the corresponding listeners. The queue is cleared after processing.

Parameters

Parameter	Type	Description
$eventName	string	the fully qualified class name of the event to dispatch from the queue, or null to dispatch all queued events

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Generated by Hazaar API Doc Generator on Tue, 06 May 2025 01:33:01 +0000