Question

before_save回调应根据以下代码将过期字段值更新为true或false：

class Package < ActiveRecord::Base
  before_save :update_availabiltiy

  def update_availabiltiy
    self.expired = date_end.to_date < Date.today
  end
end

但除非此字段的值与存储的值相同，否则它将无法工作：例如：如果此字段在DB中为真且回调中的条件将评估为true，则将保存记录，否则控制器将返回400

Started PUT "/api/venues/bogan-and-sons/packages/delicious-package" for ::1 at 2016-09-20 15:20:03 +0300
Processing by Api::PackagesController#update as JSON

Parameters: {"package"=>
  {"date_start"=>"2016-08-27T00:00:00.000-04:00", "date_end"=>"2016-12-30, ...}
}
(0.2ms)  BEGIN
(0.1ms)  ROLLBACK
Completed 400 Bad Request in 81ms (Views: 0.6ms | ActiveRecord: 17.8ms)

object.errors返回空数组，因此不存在对象的实际错误。

更新安德烈：

[31, 40] in /Users/srosca/projects/venuezz/app/models/package.rb
   31:     !expired || (Date.today <= self.date_end.to_date)
   32:   end
   33: 
   34:   def update_availabiltiy
   35:     byebug
=> 36:     self.expired = date_end.to_date < Date.today
   37:   end
   38: 
   39:   def calculate_discount
   40:     if discount_price
(byebug) expired
true
(byebug) date_end.to_date < Date.today
false
(byebug) self.expired = date_end.to_date < Date.today
false
(byebug) expired
false

Answer 1

错误的原因是before_save挂钩能够通过返回false取消保存操作（这是当您的记录未过期时会发生的情况。

返回其他内容，而不是作业结果。例如：

  def update_availabiltiy
    self.expired = date_end.to_date < Date.today

    true # no canceling
  end

在保存布尔字段的回调之前

1 个答案: