Event manager

The EventManager class provides a lightweight event system that allows you to register, detach, and trigger named events dynamically at runtime.

It is designed to simplify the management of callbacks (closures) that respond to specific application events.

This implementation supports:

• Single and bulk event attachment
• Event triggering by name (or through magic method calls)
• Checking for event existence
• Detaching single or all events
• Counting registered events

Basic usage

Attaching and Triggering Events

<?php

use Krystal\Event\EventManager;

$events = new EventManager();

// Attach an event called 'onSave'
$events->attach('onSave', function() {
    echo 'Data has been saved!';
});

// Trigger the event manually
$events->trigger('onSave'); // Output: Data has been saved!

Using magic method calls

You can trigger events simply by calling them as methods:

$events->onSave(); // Equivalent to $events->trigger('onSave');

Attaching multiple events

You can attach multiple events at once using an associative array:

$events->attachMany([
    'onStart' => function() { echo 'Application started'; },
    'onStop'  => function() { echo 'Application stopped'; }
]);

$events->trigger('onStart'); // Output: Application started
$events->trigger('onStop');  // Output: Application stopped

Detaching events

// Remove one event
$events->detach('onSave');

// Remove all registered events
$events->detachAll();

If you try to detach an event that doesn’t exist, a RuntimeException will be thrown.

Checking event existence

$events->has('onStart');       // true or false
$events->hasMany(['onStart', 'onStop']); // true if all exist

Counting registered events

echo $events->countAll(); // e.g., 2

Errors

• InvalidArgumentException — thrown if event name is not a string or listener is not callable.

• RuntimeException — thrown when trying to trigger or detach a non-existing event.