gistfile1.rb

 ...
 
 def self.update_posts_index(observer_search_data)
    update_index(observer_search_data.object_name, observer_search_data.id, observer_search_data.search_data)
  end

  def self.update_users_index(observer_search_data)
    update_index(observer_search_data.object_name, observer_search_data.id, observer_search_data.search_data)
  end

  def self.update_categories_index(observer_search_data)
    update_index(observer_search_data.object_name, observer_search_data.id, observer_search_data.search_data)
  end

  def after_save(obj)
    if obj.class == Post && obj.cooked_changed?
      search_data = obj.scrubbed_html << " " << obj.topic.title
      search_data << " " << obj.topic.category.name if obj.topic.category
      observer_search_data = ObserverSearchData.new(obj, search_data)
      SearchObserver.update_posts_index(observer_search_data)
    end
    if obj.class == User && (obj.username_changed? || obj.name_changed?)
      search_data = obj.username.dup << " " << (obj.name || "")
      observer_search_data = ObserverSearchData.new(obj, search_data)
      SearchObserver.update_users_index(observer_search_data)
    end

    if obj.class == Topic && obj.title_changed?
      if obj.posts
        post = obj.posts.where(post_number: 1).first
        if post
          search_data = post.scrubbed_html << " " << obj.title
          search_data << " " << obj.category.name if obj.category
          observer_search_data = ObserverSearchData.new(post, search_data)
          SearchObserver.update_posts_index(observer_search_data)
        end
      end
    end

    if obj.class == Category && obj.name_changed?
      observer_search_data = ObserverSearchData.new(obj, obj.name)
      SearchObserver.update_categories_index(observer_search_data)
    end
  end
  
  ...