问题的has_many：通过，缓存，触摸和counter_cache [英] Issues with has_many :through, cache, touch and counter_cache

问题描述

我有很多的has_many的：通过我的应用程序的关系。我extensivley示出与此相关的信息，如连接的对象的数目。每当用户更新的关系，连接表被修改了，我能赶上这个我扫地机。

I have a lot of has_many :through relations in my app. I am extensivley showing informations related to this, such as number of connected objects. Whenever user updates the relation, join table is modified, and I can catch this my Sweepers.

现在的问题是，该连接表项的删除，不是破坏。如果关系走了，我也没有合理的办法来检测这一点，我是从缓存中显示误导性的信息。喜欢一切：触摸=> true，或者：counter_cache =>杰作partialy。这是得到增加，如果关系被更新或创建的。但是，如果用户删除关系没有任何反应。 ：counter_cache是​​越来越坏了，：触摸不会触发。

The problem is, that join table entries are deleted, not destroyed. If relation is gone, I have no resonable way to detect this, and I am displaying misleading informations from the cache. Everything like :touch => true, or :counter_cache => true works partialy. It's get incremented if relations are updated or created. But if user removes relation nothing happens. :counter_cache is getting broken, :touch doesn't trigger.

垃圾溶液是调用.touch在控制器中，当主模型被保存。这类作品，但它似乎真的不专业。这应该是在模型逻辑，而不是在控制器

The garbage solution is to call .touch in the controller, when the main model is saved. This kind of works, but it seems really non-professional. This should be in the model logic, not in the controllers.

我觉得我失去了一些东西很大，但不能让我的头了这一点。任何人都可以把一些有识之士对这个问题？

I feel like I am missing something big, but cant get my head over this. Anyone could put some insight on this problem?

推荐答案

猴子打补丁活动记录是没有必要的。当定义你的公会，将：依赖选项：破坏

Monkey patching Active Record isn't necessary. When defining your association, set the :dependent option to :destroy.

class Book < ActiveRecord::Base
  has_many :authorships, :dependent => :destroy
  has_many :authors, :through => :authorships, :dependent => :destroy
end

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