Notify::getUserEmail

static function getUserEmail(Order $order)
{
	$userEmail = "";

	if (!empty(static::$cacheUserData[$order->getId()]))
	{
		$userData = static::$cacheUserData[$order->getId()];
		if (!empty($userData['EMAIL']))
		{
			$userEmail = $userData['EMAIL'];
		}
	}


	if (empty($userEmail))
	{
		/** @var PropertyValueCollection $propertyCollection */
		if ($propertyCollection = $order->getPropertyCollection())
		{
			if ($propUserEmail = $propertyCollection->getUserEmail())
			{
				$userEmail = $propUserEmail->getValue();
				static::$cacheUserData[$order->getId()]['EMAIL'] = $userEmail;
			}
		}
	}

	if (empty($userEmail))
	{
		$userRes = MainUserTable::getList(array(
											   'select' => array('ID', 'LOGIN', 'NAME', 'LAST_NAME', 'SECOND_NAME', 'EMAIL'),
											   'filter' => array('=ID' => $order->getUserId()),
										   ));
		if ($userData = $userRes->fetch())
		{
			static::$cacheUserData[$order->getId()] = $userData;
			$userEmail = $userData['EMAIL'];
		}
	}

	return $userEmail;
}