gistfile1.rb

require 'spreadsheet'

class CategoryXls

  def initialize(file_path)
    @file_path = file_path
  end

  def import
    read( @file_path ) do |sheet, row|
      ( category = load_category row[0].to_s ) unless category_name.empty?
      ( load_subcategory row[1].to_s, category.id ) unless subcategory_name.empty?
    end
  end

  private

  def load_category( category_name )
    category = ItemCategory.find_or_create_by( :name => category_name )
    puts "Categories: #{ category.name }"
    category
  end

  def load_subcategory(subcategory_name, category_id)
    item_category = ItemCategory.categories.where( :name => subcategory_name ).first

    # A lo mejor esto se  puede reemplazar por un find_or_create.                                                
    if item_category.nil?
      subcategories = ItemCategory.create_subcategory!( subcategory_name, category_id )
    else
      subcategories = item_category.update_attributes( item_category_id: category_id )
    end
  end

 def read
    Spreadsheet.open( @file_path ) do |book|

      book.worksheets.each do |ws|
        0.upto ws.last_row_index do |index|
          row = ws.row(index)
          yield ws, row
        end
      end
    end
end