title: Call a class method in an after_save
body: <p>That is may be a stupid point, but I don't find the solution.</p>
  
  <p>I have a simple model with a class method <code>update_menu</code> and I want that it is called after each save of instance.</p>
  
  <pre><code>Class Category
    attr_accessible :name, :content
  
  
    def self.menu
       @@menu ||= update_menu
    end
  
    def self.update_menu
       @@menu = Category.all
    end
  end
  </code></pre>
  
  <p>So what is the correct syntax to get the <code>after_filter</code> call <code>update_menu</code>?</p>
  
  <p>I tried:</p>
  
  <pre><code>after_save :update_menu
  </code></pre>
  
  <p>But it looks for the method on the instance (which does not exist) and not on the class.</p>
  
  <p>Thanks for your answers.</p>