Fragment::walkWidth

public function walkWidth($cb, $rootId = 0)
{
	$result = new Result();
	if(!is_callable($cb))
	{
		return $result;
	}

	$index = $this->getIndex();
	$data = array();

	$rootId = intval($rootId);

	$queue = array($rootId);
	$met = array();
	$limit = 0;
	while(count($queue))
	{
		$limit++;
		if($limit > 10000)
		{
			break;
		}

		$nextId = array_shift($queue);
		if(isset($met[$nextId]))
		{
			continue; // do not go the same way twice
		}
		$met[$nextId] = true;

		if($nextId)
		{
			$data[$nextId] = call_user_func_array(
				$cb,
				array(
					null/** todo: object will be here some day, on which we can do ->getParentId() or even ->getParent() */,
					$nextId,
					$this->values[$nextId] ?? null,
					$this->getParentIdFor($nextId)
				)
			);
		}
		if(array_key_exists($nextId, $index))
		{
			foreach($index[$nextId] as $subNodeId => $subNode)
			{
				array_push($queue, $subNodeId);
			}
		}
	}

	$result->setData($data);

	if($limit > 10000)
	{
		$result->addError('ILLEGAL_STRUCTURE.DEPTH', 'Illegal fragment structure');
	}

	return $result;
}