itemcollection.php

См. документацию.

<?
 
namespace Bitrix\UI\EntitySelector;
 
class ItemCollection implements \IteratorAggregate, \JsonSerializable
{
    private $items = [];
    private $itemsByEntity = [];
 
    public function __construct()
    {
    }
 
    public function add(Item $item): bool
    {
        if ($this->has($item))
        {
            return false;
        }
 
        if (!isset($this->itemsByEntity[$item->getEntityId()]))
        {
            $this->itemsByEntity[$item->getEntityId()] = [];
        }
 
        $this->itemsByEntity[$item->getEntityId()][$item->getId()] = $item;
        $this->items[] = $item;
 
        return true;
    }
 
    public function get(string $entityId, $itemId): ?Item
    {
        return $this->itemsByEntity[$entityId][$itemId] ?? null;
    }
 
    public function has(Item $item): bool
    {
        return isset($this->itemsByEntity[$item->getEntityId()][$item->getId()]);
    }
 
    public function getAll(): array
    {
        return $this->items;
    }
 
    public function count(): int
    {
        return count($this->items);
    }
 
    public function getEntityItems(string $entityId): array
    {
        return $this->itemsByEntity[$entityId] ?? [];
    }
 
    public function toJsObject(): string
    {
        $items = $this->toArray();
 
        return \CUtil::phpToJSObject($items, false, false, true);
    }
 
    public function toArray(): array
    {
        return array_map(function(Item $item) {
            return $item->toArray();
        }, $this->getAll());
    }
 
    public function jsonSerialize()
    {
        return $this->items;
    }
 
    public function getIterator(): \ArrayIterator
    {
        return new \ArrayIterator($this->items);
    }
}