strip_accents.rb

# encoding: utf-8

String.class_eval do
  def strip_accents
    accents = {
      ['à','À','ả','Ả','ã','Ã','á','Á','ạ','Ạ','ă','Ă','ằ','Ằ','ẳ','Ẳ','ẵ','Ẵ','ắ','Ắ','ặ','Ặ','â','Â','ầ','Ầ','ẩ','Ẩ','ẫ','Ẫ','ấ','Ấ','ậ','Ậ'] => 'a',
      ['đ','Đ'] => "d",
      ['è','È','ẻ','Ẻ','ẽ','Ẽ','é','É','ẹ','Ẹ','ê','Ê','ề','Ề','ể','Ể','ễ','Ễ','ế','Ế','ệ','Ệ'] => "e",
      ['ì','Ì','ỉ','Ỉ','ĩ','Ĩ','í','Í','ị','Ị'] => 'i',
      ['ò','Ò','ỏ','Ỏ','õ','Õ','ó','Ó','ọ','Ọ','ô','Ô','ồ','Ồ','ổ','Ổ','ỗ','Ỗ','ố','Ố','ộ','Ộ','ơ','Ơ','ờ','Ờ','ở','Ở','ỡ','Ỡ','ớ','Ớ','ợ','Ợ'] => "o",
      ['ù','Ù','ủ','Ủ','ũ','Ũ','ú','Ú','ụ','Ụ','ư','Ư','ừ','Ừ','ử','Ử','ữ','Ữ','ứ','Ứ','ự','Ự'] => "u",
      ['ý','Ý', 'ỷ','Ỷ', 'ỳ','Ỳ', 'ỹ', 'Ỹ', 'ỵ', 'Ỵ'] => "y"
    }
    str = self
    accents.each do |ac,rep|
      ac.each do |s|
      str = str.gsub(s, rep)
      end
    end
    str.downcase
  end
end