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

上面的方法虽然可以用但，逻辑上并不好，因为Model不是helper，所以可以用下面的方法

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