CLearnHelper::getUpdatedToGraphStatus

static function getUpdatedToGraphStatus()
{

	$rc = COption::GetOptionString(self::MODULE_ID, self::OPTION_ID, self::DEFAULT_VALUE, self::SITE_ID);

	// status wasn't set yet (we must determine, is our tables updated to graph or not)
	if ($rc === self::DEFAULT_VALUE)
	{
		// Set determined mode in global options
		self::setUpdatedToGraphStatus(self::GRAPH_STATUS_LEGACY);
	}

	$allowed_statuses = array (
		self::GRAPH_STATUS_LEGACY,
		self::GRAPH_STATUS_UPDATED_TO_GRAPH,
		self::GRAPH_STATUS_UNDEFINED
		);

	if ( ! in_array($rc, $allowed_statuses, true) )
	{
		AddMessage2Log('Invalid COption ~CLearnHelper::isUpdatedToGraph();: `'
			. $rc . '`;', 'learning');

		$rc = self::GRAPH_STATUS_UNDEFINED;
	}

	return ($rc);
}