Box\Spout\Writer\XLSX\Helper\FileSystemHelper::zipRootFolderAndCopyToStream PHP Method

    public function zipRootFolderAndCopyToStream($streamPointer)
    {
        $zipHelper = new ZipHelper($this->rootFolder);
        // In order to have the file's mime type detected properly, files need to be added
        // to the zip file in a particular order.
        // "[Content_Types].xml" then at least 2 files located in "xl" folder should be zipped first.
        $zipHelper->addFileToArchive($this->rootFolder, self::CONTENT_TYPES_XML_FILE_NAME);
        $zipHelper->addFileToArchive($this->rootFolder, self::XL_FOLDER_NAME . '/' . self::WORKBOOK_XML_FILE_NAME);
        $zipHelper->addFileToArchive($this->rootFolder, self::XL_FOLDER_NAME . '/' . self::STYLES_XML_FILE_NAME);
        $zipHelper->addFolderToArchive($this->rootFolder, ZipHelper::EXISTING_FILES_SKIP);
        $zipHelper->closeArchiveAndCopyToStream($streamPointer);
        // once the zip is copied, remove it
        $this->deleteFile($zipHelper->getZipFilePath());
    }