ruby-on-rails - rails before_create 不触发方法

Question

我正在尝试在保存实例之前触发一个方法。我有 User模型:

class User < ActiveRecord::Base

    has_secure_password
    attr_accessible :name, :first_surname,:second_surname,:email, :password, :password_confirmation,:number,:credit

    before_save{ self.email.downcase! }
    before_create :generate_auth_token

    default_scope order: 'users.created_at ASC'

    has_many :operations

    def consume(what,price,agent)
        self.operations.create(category:what,price:price, agent_id:agent)
    end
end

和每个 User有很多 Operation (注意通过 binding.pry 使用 pry 调试器:

class Operation < ActiveRecord::Base
  attr_accessible :agent_id, :comment, :postcredit, :precredit, :category, :user_id,:price
  validates_presence_of :user_id
  validates_presence_of :agent_id
  validates_presence_of :price
  validates_presence_of :precredit
  validates_presence_of :postcredit
  validates_presence_of :category
  #before_save :compute_prices, :on => :create
  before_create :compute_prices
  belongs_to :user

  private

  def compute_prices
      binding.pry
      user=User.find(self.user_id)
      self.precredit=user.credit
      #select whether adding or subtracting
      if self.category == 'credit'
          self.postcredit=self.precredit+self.price
      else
          self.postcredit=self.precredit-self.price
      end
      user.update_attributes(credit:self.postcredit)
  end
end

我用用户和操作填充数据库，并通过控制台进行测试 $rails c --sandbox .然后我:

>fi=User.first
>ope=fi.operations.create(category:'credit',price:12.2,agent_id:3)
#Now here the debugger should start and does not

我用这两个都试试 before_create和 before_save ，但没有工作。

before_create :compute_prices
before_save :compute_prices, :on => :create

唯一有效的选项是 after_initialize :compute_prices ，但这会在每次 find 后触发或初始化。
有任何想法吗？
解决方案
正如对第一个答案的评论所解释的那样，解决方案是用户 before_validation (function), on: :create , 而不是 before_save ... .

Answer 1

你的操作有效吗？回调生命周期在这里:http://api.rubyonrails.org/classes/ActiveRecord/Callbacks.html如果验证失败，它将无法进入创建回调