class Product << ActiveRecord::Base
  before_save :clean_name_description_details

  def clean_name_description_details
    # clean up the name
    if name_changed?
      self.name = self.name.clean_non_utf8
    end
    if description_changed?
      self.description = self.description.clean_non_utf8
    end
    if details_changed?
      self.details = self.details.clean_non_utf8
    end
  end
end


# lib/extensions/string.rb
class String
  def clean_non_utf8
    converter = Iconv.new('UTF-8//IGNORE//TRANSLIT', 'ASCII//IGNORE//TRANSLIT')
    self.gsub!(/[\u00BC]/," 1/4").gsub!(/[\u00BD]/," 1/2").gsub!(/[\u00BE]/," 3/4")
    self.gsub!(/[\u2018\u2019\u201A\u201B\u2032\u2035]/,"'").gsub!(/[\u201C\u201D\u201E\u201F\u2033\u2036]/,'"')
    converter.iconv(self).unpack('U*').select{|cp| cp < 127}.pack('U*')
  end