Piwik\Plugins\Referrers\API::getKeywordNotDefinedString PHP Method

    public static function getKeywordNotDefinedString()
    {
        return Piwik::translate('General_NotDefined', Piwik::translate('General_ColumnKeyword'));
    }

 /**
  * Returns a summary for a visit's referral.
  *
  * @param Row $visit
  * @return bool|mixed|string
  * @ignore
  */
 public static function getReferrerSummaryForVisit($visit)
 {
     $referrerType = $visit->getColumn('referrerType');
     if ($referrerType === false || $referrerType == 'direct') {
         $result = Piwik::translate('Referrers_DirectEntry');
     } else {
         if ($referrerType == 'search') {
             $result = $visit->getColumn('referrerName');
             $keyword = $visit->getColumn('referrerKeyword');
             if ($keyword !== false && $keyword != APIReferrers::getKeywordNotDefinedString()) {
                 $result .= ' (' . $keyword . ')';
             }
         } else {
             if ($referrerType == 'campaign') {
                 $result = Piwik::translate('Referrers_ColumnCampaign') . ' (' . $visit->getColumn('referrerName') . ')';
             } else {
                 $result = $visit->getColumn('referrerName');
             }
         }
     }
     return $result;
 }