instancemap.php

<?php
 
namespace Bitrix\Calendar\Sync\Entities;
 
use Bitrix\Calendar\Core\Base\Date;
use Bitrix\Calendar\Core\Base\Map;
 
class InstanceMap extends Map
{
    public const DATE_FORMAT_FOR_KEY = 'Ymd';
 
    public static function getKeyByDate(Date $originalDate): string
    {
        return $originalDate->format(self::DATE_FORMAT_FOR_KEY);
    }
 
    public function add($item, $key = null): self
    {
        if ($key === null)
        {
            if ($date = $item->getEvent()->getOriginalDateFrom())
            {
                $key = self::getKeyByDate($date);
            }
            else
            {
                $key = self::getKeyByDate($item->getEvent()->getStart());
            }
        }
 
        parent::add($item, $key);
 
        return $this;
    }
 
    public function addItems(array $items): self
    {
        foreach ($items as $item)
        {
            $this->add($item);
        }
 
        return $this;
    }
}