CBPHelper::extractUsers

static function extractUsers($arUsersDraft, $documentId, $bFirst = false)
{
	$result = [];

	if (!is_array($arUsersDraft))
	{
		$arUsersDraft = array($arUsersDraft);
	}

	$l = mb_strlen("user_");
	$documentService = CBPRuntime::GetRuntime(true)->getDocumentService();

	foreach ($arUsersDraft as $user)
	{
		if (!is_scalar($user))
		{
			continue;
		}

		if (mb_substr($user, 0, $l) === "user_")
		{
			$user = intval(mb_substr($user, $l));
			if (($user > 0) && !in_array($user, $result))
			{
				if ($bFirst)
				{
					return $user;
				}
				$result[] = $user;
			}
		}
		elseif (CBPActivity::isExpression($user))
		{
			$parsed = CBPActivity::parseExpression($user);
			if ($parsed && $parsed['object'] === 'Document')
			{
				$document = $documentService->GetDocument($documentId);
				if ($document && $document[$parsed['field']])
				{
					foreach ((array) $document[$parsed['field']] as $docUser)
					{
						if (mb_substr($docUser, 0, $l) === "user_")
						{
							$user = intval(mb_substr($docUser, $l));
							if (($user > 0) && !in_array($user, $result))
							{
								if ($bFirst)
								{
									return $user;
								}
								$result[] = $user;
							}
						}
					}
				}
			}
		}
		else
		{
			$users = self::extractUsersFromExtendedGroup($user);
			if ($users === false)
			{
				$users = $documentService->GetUsersFromUserGroup($user, $documentId);
			}
			foreach ($users as $u)
			{
				$u = (int)$u;
				if (($u > 0) && !in_array($u, $result))
				{
					if ($bFirst)
					{
						return $u;
					}
					$result[] = $u;
				}
			}
		}
	}

	if (!$bFirst)
	{
		return $result;
	}

	if (count($result) > 0)
	{
		return $result[0];
	}

	return null;
}