UserTypePropertyDiskFile::convertTo

static function convertTo(FieldType $fieldType, $value, $toTypeClass)
	{
		if (is_array($value) && isset($value['VALUE']))
			$value = $value['VALUE'];

		$value = (int) $value;

		/** @var Base $toTypeClass */
		$type = $toTypeClass::getType();
		switch ($type)
		{
			case FieldType::FILE:
				$diskFile = File::getById($value);
				$value = $diskFile? $diskFile->getFileId() : null;
				break;
			default:
				$value = null;
		}

		return $value;
	}