string.rb

require 'singleton'

class String
  
  class TextHelperSingleton
    include Singleton
    include ActionView::Helpers::TextHelper
  end
  
  def method_missing(method, *args)
    if TextHelperSingleton.instance.respond_to?(method)
      TextHelperSingleton.instance.send(method, self, *args)
    else
      super
    end
  end
  
end