Parsing a .xls price list with several categories using Spreadsheet gem

gistfile1.rb

def create
  require 'spreadsheet'

  #for debugging purposes the file path is hardcoded
  book = Spreadsheet.open "#{Rails.root}/public/price.xls"
  sheet = book.worksheet 0

  sheet.each do |row|
    font = row.format(0).font # read font data of the first cell in the row
    
    # My spreadsheet has 2 levels of categories, but I only need the second
    if font.weight == 400 # subcategory or unit

      if font.size == 11 # subcategory

        @category.units.create(@units) if !@category.nil?

        @units = [] # (re)initialize the array

        begin
          @category = Category.find_by_title row[0]
        rescue # in case there is no such category
          @category = nil
        end

      else # unit
        if !@category.nil? 
          @units.push({ :title => row[0], :wholesale => row[1], #:retail => row[2] })
        end
      end
    end
  end
end

This recognizes the font size and by doing so distinguishes between the colors.