缓存清理器不适用于自定义方法Rails 4

Question

我在我的rails 4项目中使用了片段缓存。我有cities controller和city_sweeper

cities_controller.rb
   cache_sweeper :city_sweeper, :only => [:update, :destroy]
   .
   .
   def update_featured
    @city = City.unscoped.find(params[:id])
    if params[:featured]
      @city.update_attribute(:featured, params[:featured])
    end
    render :text => "success:
   end
   .
end

在我的city_sweeper.rb中我有这样的代码

class CitySweeper < ActionController::Caching::Sweeper
 observe City

 def after_update(city)
  expire_cache(city)
 end

 def after_destroy(city)
  expire_cache(city)
 end

 def after_update_featured(city)
  expire_cache(city)
 end

 def expire_cache(city)
  expire_fragment "city_index_#{city.id}"   
 end
end

它可以很好地处理CRUD操作，但是它不能用于调用我的sweeper.rb的自定义method.its，但是我不能在那里获得城市对象。我得到了这个错误：

 NoMethodError (undefined method `expire_fragment' for #<CitySweeper:0xab9f1e0 @controller=nil>):

Answer 1

您可以使用以下命令使fragment cache过期

更新

if @cities.present?
  @cities.each do |city|
    cache(action: 'recent_update',key: "city_index_#{city.id}", skip_digest: true) do
    ...
    end
  end
end

在清扫程序中

class CitySweeper < ActionController::Caching::Sweeper
  observe City

  .....
  def expire_cache(city)  
    expire_fragment(controller: 'cities', action: 'recent_update',key: "city_index_#{city.id}")
  end
end