Ruby on rails Rails：检查哪个方法启动了内部保存：在保存之前

我想运行一个方法，跟踪CRUD中记录属性的更改，但仅当这些更改与更新操作一起保存时。我现在在模型中有这个：

before_save :check_changed
def check_changed
  puts "Period Contributions Changed? : #{period_contributions_changed?}"
  puts "Total Contributions Changed? : #{total_contributions_changed?}"
  puts "Period Expenditures Changed? : #{period_expenditures_changed?}"
  puts "Total Expenditures Changed? : #{total_expenditures_changed?}"
end

---

但这也取决于新记录的创造。我是否可以在check_changed方法中执行测试，以确定记录是否已创建或更新？谢谢

查看条件回调：如果和：除非

before_save :check_changed, unless: :new_record?

或者您可以在方法中使用“新记录”

def check_changed

  return if new_record?

  puts "Period Contributions Changed? : #{period_contributions_changed?}"
  puts "Total Contributions Changed? : #{total_contributions_changed?}"
  puts "Period Expenditures Changed? : #{period_expenditures_changed?}"
  puts "Total Expenditures Changed? : #{total_expenditures_changed?}"
end

编辑：也应该签出

after_save :check_changed, on: [:update]

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