BFile::upload

public function upload(array $file)
{
	$result = new AddResult();
	$path = $this->getPath($file);
	$fileId = CFile::saveFile($file, $path, true, true);
	if($fileId > 0)
	{
		$result->setId($fileId);
	}
	else
	{
		$result->addError(new Error('Cant save file to b_file'));
	}

	return $result;
}