event.php

<?php
namespace Bitrix\Catalog\Model;
 
use Bitrix\Main,
    Bitrix\Main\Localization\Loc,
    Bitrix\Catalog;
 
Loc::loadMessages(__FILE__);
 
class Event extends Main\Event
{
    protected $entity = null;
 
    protected static $catalogHandlerExist = [];
 
    private static $keys = ['fields', 'external_fields', 'actions'];
 
    public function __construct(Entity $entity, string $type, array $parameters = [])
    {
        $this->entity = $entity;
 
        parent::__construct('catalog', self::makeEventName(get_class($this->entity), $type), $parameters);
    }
 
    public function getErrors(Main\Result $result): bool
    {
        $hasErrors = false;
 
        foreach($this->getResults() as $eventResult)
        {
            if ($eventResult->getType() === Main\Entity\EventResult::ERROR)
            {
                $hasErrors = true;
                $result->addErrors($eventResult->getErrors());
            }
        }
        return $hasErrors;
    }
 
    public function mergeData(array &$data): void
    {
        foreach($this->getResults() as $eventResult)
        {
            $removed = $eventResult->getUnset();
            foreach (self::$keys as $index)
            {
                if (empty($removed[$index]))
                    continue;
                foreach ($removed[$index] as $key)
                    unset($data[$index][$key]);
                unset($key);
            }
            unset($removed);
            $modified = $eventResult->getModified();
            foreach (self::$keys as $index)
            {
                if (empty($modified[$index]))
                    continue;
                $data[$index] = array_merge($data[$index], $modified[$index]);
            }
            unset($modified);
        }
    }
 
    public static function existEventHandlers(Entity $entity, string $eventName): bool
    {
        return static::existEventHandlersById(self::makeEventName(get_class($entity), $eventName));
    }
 
    public static function makeEventName(string $class, string $eventName): string
    {
        return $class.'::'.$eventName;
    }
 
    public static function existEventHandlersById(string $id): bool
    {
        if (!isset(self::$catalogHandlerExist[$id]))
        {
            $eventManager = Main\EventManager::getInstance();
            $eventsList = $eventManager->findEventHandlers(
                'catalog', $id
            );
            self::$catalogHandlerExist[$id] = !empty($eventsList);
            unset($eventsList, $eventManager);
        }
        return self::$catalogHandlerExist[$id];
    }
}