fieldcollection.php

См. документацию.

<?php
 
namespace Bitrix\Location\Entity\Generic;
 
use Bitrix\Main\SystemException;

abstract class FieldCollection extends Collection
{
    protected $items = [];

    public function isItemExist(int $type): bool
    {
        foreach($this->items as $item)
        {
            if($item->getType() === $type)
            {
                return true;
            }
        }
 
        return false;
    }

    public function getItemByType(int $type): ?IField
    {
        foreach($this->items as $item)
        {
            if($item->getType() === $type)
            {
                return $item;
            }
        }
 
        return null;
    }

    public function getSortedItems(): array
    {
        $result = $this->items;
 
        uasort(
            $result,
            function ($a, $b)
            {
                if ($a->getType() == $b->getType())
                {
                    return 0;
                }
                return ($a->getType() < $b->getType()) ? -1 : 1;
            }
        );
 
        return $result;
    }

    public function addItem($item): int
    {
        if($this->isItemExist($item->getType()))
        {
            throw new SystemException('Item with type "'.$item->getType().'" already exist in this collection');
        }
 
        return parent::addItem($item);
    }
}