怎么在model里使用view helper

如何在model里使用view helper

class Glosentry < ActiveRecord::Base  include ActionView::Helpers::TextHelper    def short_explanation(len=20)     truncate(self.explanation, len)  endend

class Glosentry < ActiveRecord::Base  class GlosentryHelper    include ActionView::Helpers::TextHelper  end    def helper    @h ||= GlosentryHelper.new  end    def short_explanation(len=20)     helper.truncate(self.explanation, len)  endend

  def method_missing(*args, &block)    @h.send(*args, &block)  end