Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Xlsx/DocProps.php
public function writeDocPropsApp(Spreadsheet $spreadsheet)
    {
        // Create XML writer
        $objWriter = null;
        if ($this->getParentWriter()->getUseDiskCaching()) {
            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
        } else {
            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
        }

        // XML header
        $objWriter->startDocument('1.0', 'UTF-8', 'yes');

        // Properties
        $objWriter->startElement('Properties');
        $objWriter->writeAttribute('xmlns', 'http://schemas.openxmlformats.org/officeDocument/2006/extended-properties');
        $objWriter->writeAttribute('xmlns:vt', 'http://schemas.openxmlformats.org/officeDocument/2006/docPropsVTypes');

        // Application
        $objWriter->writeElement('Application', 'Microsoft Excel');

        // DocSecurity
        $objWriter->writeElement('DocSecurity', '0');

        // ScaleCrop
        $objWriter->writeElement('ScaleCrop', 'false');

        // HeadingPairs
        $objWriter->startElement('HeadingPairs');

        // Vector
        $objWriter->startElement('vt:vector');
        $objWriter->writeAttribute('size', '2');
        $objWriter->writeAttribute('baseType', 'variant');

        // Variant
        $objWriter->startElement('vt:variant');
        $objWriter->writeElement('vt:lpstr', 'Worksheets');
        $objWriter->endElement();

        // Variant
        $objWriter->startElement('vt:variant');
        $objWriter->writeElement('vt:i4', $spreadsheet->getSheetCount());
        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

        // TitlesOfParts
        $objWriter->startElement('TitlesOfParts');

        // Vector
        $objWriter->startElement('vt:vector');
        $objWriter->writeAttribute('size', $spreadsheet->getSheetCount());
        $objWriter->writeAttribute('baseType', 'lpstr');

        $sheetCount = $spreadsheet->getSheetCount();
        for ($i = 0; $i < $sheetCount; ++$i) {
            $objWriter->writeElement('vt:lpstr', $spreadsheet->getSheet($i)->getTitle());
        }

        $objWriter->endElement();

        $objWriter->endElement();

        // Company
        $objWriter->writeElement('Company', $spreadsheet->getProperties()->getCompany());

        // Company
        $objWriter->writeElement('Manager', $spreadsheet->getProperties()->getManager());

        // LinksUpToDate
        $objWriter->writeElement('LinksUpToDate', 'false');

        // SharedDoc
        $objWriter->writeElement('SharedDoc', 'false');

        // HyperlinksChanged
        $objWriter->writeElement('HyperlinksChanged', 'false');

        // AppVersion
        $objWriter->writeElement('AppVersion', '12.0000');

        $objWriter->endElement();

        // Return
        return $objWriter->getData();
    }
public function writeDocPropsApp(Spreadsheet $spreadsheet)
    {
        // Create XML writer
        $objWriter = null;
        if ($this->getParentWriter()->getUseDiskCaching()) {
            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
        } else {
            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
        }

        // XML header
        $objWriter->startDocument('1.0', 'UTF-8', 'yes');

        // Properties
        $objWriter->startElement('Properties');
        $objWriter->writeAttribute('xmlns', 'http://schemas.openxmlformats.org/officeDocument/2006/extended-properties');
        $objWriter->writeAttribute('xmlns:vt', 'http://schemas.openxmlformats.org/officeDocument/2006/docPropsVTypes');

        // Application
        $objWriter->writeElement('Application', 'Microsoft Excel');

        // DocSecurity
        $objWriter->writeElement('DocSecurity', '0');

        // ScaleCrop
        $objWriter->writeElement('ScaleCrop', 'false');

        // HeadingPairs
        $objWriter->startElement('HeadingPairs');

        // Vector
        $objWriter->startElement('vt:vector');
        $objWriter->writeAttribute('size', '2');
        $objWriter->writeAttribute('baseType', 'variant');

        // Variant
        $objWriter->startElement('vt:variant');
        $objWriter->writeElement('vt:lpstr', 'Worksheets');
        $objWriter->endElement();

        // Variant
        $objWriter->startElement('vt:variant');
        $objWriter->writeElement('vt:i4', $spreadsheet->getSheetCount());
        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

        // TitlesOfParts
        $objWriter->startElement('TitlesOfParts');

        // Vector
        $objWriter->startElement('vt:vector');
        $objWriter->writeAttribute('size', $spreadsheet->getSheetCount());
        $objWriter->writeAttribute('baseType', 'lpstr');

        $sheetCount = $spreadsheet->getSheetCount();
        for ($i = 0; $i < $sheetCount; ++$i) {
            $objWriter->writeElement('vt:lpstr', $spreadsheet->getSheet($i)->getTitle());
        }

        $objWriter->endElement();

        $objWriter->endElement();

        // Company
        $objWriter->writeElement('Company', $spreadsheet->getProperties()->getCompany());

        // Company
        $objWriter->writeElement('Manager', $spreadsheet->getProperties()->getManager());

        // LinksUpToDate
        $objWriter->writeElement('LinksUpToDate', 'false');

        // SharedDoc
        $objWriter->writeElement('SharedDoc', 'false');

        // HyperlinksChanged
        $objWriter->writeElement('HyperlinksChanged', 'false');

        // AppVersion
        $objWriter->writeElement('AppVersion', '12.0000');

        $objWriter->endElement();

        // Return
        return $objWriter->getData();
    }
Write docProps/app.xml to XML format.

@param Spreadsheet $spreadsheet

@throws \PhpOffice\PhpSpreadsheet\Writer\Exception

@return string XML Output