xls-helpers.rb

  #
  # XLS helpers
  #
  def xls_header
    <<~EOF
      <?xml version="1.0"?>
      <Workbook xmlns="urn:schemas-microsoft-com:office:spreadsheet"
        xmlns:o="urn:schemas-microsoft-com:office:office"
        xmlns:x="urn:schemas-microsoft-com:office:excel"
        xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet"
        xmlns:html="http://www.w3.org/TR/REC-html40">
        <Worksheet ss:Name="Sheet1">
          <Table>
    EOF
  end

  def xls_footer
    <<~EOF
          </Table>
        </Worksheet>
      </Workbook>
    EOF
  end

  def xls_start_row
    "\n      <Row>"
  end

  def xls_end_row
    "\n      </Row>"
  end

  def xls_cell(data)
    "\n        <Cell><Data ss:Type=\"#{xls_type(data)}\">#{CGI.escapeHTML(data.to_s)}</Data></Cell>"
  end

  def xls_type(data)
    if /\A\d[\d.]*\z/ =~ data
      'Number'
    else
      'String'
    end
  end