Ruby before_validation触发无限循环回叫 [英] Ruby before_validation triggers infinite loop of call back

问题描述

产品模型具有一个attribute_1。如果attribute_1需要重新计算，则将调用before_validation。它导致 SystemStackError：堆栈级别太深，因为 self.save！触发 before_validation 。如何停止无限循环的回叫。

  before_validation：method_1，：if => ：recalculation_required_attribute 
  

我正在使用 lock_version 。 update_all不会增加 lock_version 。所以我正在使用保存！。

  def method_1 
 #### 
 ## ## 
如果self.lock_version == Product.find（self.id）.lock_version 
 Product.where（：id => self.id）.update_all（属性）
 self。属性=属性
 self.save！ 
结束
结束
  




解决方案

您不需要 self.save！那里：您已经在事务中了，所以只要做想做的事情，让Rails在完成后保存记录即可。 / p>



侧面注释：

• Product.where（：id => self.id）.update_all（属性）可能可以重写为 products.update_all（attributes）（关联为 this_model has_many：products


• self.attributes =属性是多余的，除非属性是一个实例方法。

Product Model has an attribute_1. If recalculation is required for attribute_1 then before_validation will call. It giving SystemStackError: stack level too deep because self.save! triggers the before_validation. How to stop infinite loop of call back.

before_validation :method_1, :if => :recalculation_required_attribute

I am using optimistic locking using lock_version. 'update_all' will not increase the lock_version. So I am using save!. It is calling the infinite look of call back.

def method_1
    ####
    ####
    if self.lock_version == Product.find(self.id).lock_version
       Product.where(:id => self.id).update_all(attributes)
       self.attributes = attributes
       self.save!
    end
end

解决方案

You don't need self.save! there: you are already inside the transaction, so just do whatever you want to do and let Rails save the record once you are done.

Sidenotes:

• Product.where(:id => self.id).update_all(attributes) probably could be rewritten as products.update_all(attributes) (having the association this_model has_many :products
• self.attributes = attributes is redundant unless attributes is an instance method.

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