subscribers[ $event ] ) ) { $this->subscribers[ $event ] = array(); } $this->subscribers[ $event ][] = $callback; } /** * Publish an event to all subscribers. * * @param string $event The event name. * @param mixed ...$args Arguments to pass to the callbacks. * @return void */ public function publish( string $event, ...$args ): void { if ( ! isset( $this->subscribers[ $event ] ) ) { return; } foreach ( $this->subscribers[ $event ] as $callback ) { call_user_func( $callback, ...$args ); } } /** * Unsubscribe a specific callback from an event. * * @param string $event The event name. * @param callable $callback The callback to remove. * @return void */ public function unsubscribe( string $event, callable $callback ): void { if ( ! isset( $this->subscribers[ $event ] ) ) { return; } $this->subscribers[ $event ] = array_filter( $this->subscribers[ $event ], fn( $subscriber ) => $subscriber !== $callback ); if ( empty( $this->subscribers[ $event ] ) ) { unset( $this->subscribers[ $event ] ); } } }