Piwik\DataTable\Renderer\Csv::buildCsvString PHP Метод

    private function buildCsvString($allColumns, $csv)
    {
        $str = '';
        // specific case, we have only one column and this column wasn't named properly (indexed by a number)
        // we don't print anything in the CSV file => an empty line
        if (sizeof($allColumns) == 1 && reset($allColumns) && !is_string(key($allColumns))) {
            $str .= '';
        } else {
            // render row names
            $str .= $this->getHeaderLine(array_keys($allColumns)) . $this->lineEnd;
        }
        // we render the CSV
        foreach ($csv as $theRow) {
            $rowStr = '';
            foreach ($allColumns as $columnName => $true) {
                $rowStr .= $this->formatValue($theRow[$columnName]) . $this->separator;
            }
            // remove the last separator
            $rowStr = substr_replace($rowStr, "", -strlen($this->separator));
            $str .= $rowStr . $this->lineEnd;
        }
        $str = substr($str, 0, -strlen($this->lineEnd));
        return $str;
    }