Piwik\API\DataTableManipulator\ReportTotalsCalculator::sumColumnValueToTotal PHP Method

    private function sumColumnValueToTotal($columns, $metricId, $metricName)
    {
        $value = false;
        if (array_key_exists($metricId, $columns)) {
            $value = $columns[$metricId];
        }
        if ($value === false) {
            // we do not add $metricId to $possibleMetricNames for a small performance improvement since in most cases
            // $metricId should be present in $columns so we avoid this foreach loop
            $possibleMetricNames = array($metricName, 'Goal_' . $metricName, 'Actions_' . $metricName);
            foreach ($possibleMetricNames as $possibleMetricName) {
                if (array_key_exists($possibleMetricName, $columns)) {
                    $value = $columns[$possibleMetricName];
                    break;
                }
            }
            if ($value === false) {
                return;
            }
        }
        if (array_key_exists($metricName, $this->totals)) {
            $this->totals[$metricName] += $value;
        } else {
            $this->totals[$metricName] = $value;
        }
    }