gistfile1.rb

class Order < ActiveRecord::Base

   def processing_fee

     packages_with_processing_fees = ['Package', 'FamilyPackage', 'LadiesPackage', 'CompletePackage']
     fee = 0
     # Only apply fee if cart contains an item with processing fees
     fee = 3.00 if line_items.any? {|line_item| packages_with_processing_fees.include? line_item.item.class.to_s } 

       if customer
         fee = 5.00 unless "Canada United States Mexico".include? customer.country
       end