Rails 3 Transactions，回滚一切

Question

class Bear < ActiveRecord::Base 
    def feed! 
     self.transaction do 
      raise Exception unless self.foods_eaten << Food.new(:name => "fish") 
      self.fed_at = Time.now 
      save! 
     end 
    end 
end 

class Hippo < ActiveRecord::Base 
    def wash! 
     self.transaction do 
      @soap.inventory -= 1 
      @soap.save! 
      self.washed_at = Time.now 
      save! 
     end 
    end 
end 

class ZookeeperController < ApplicationController 

    def chores 
     @zookeeper = Zookeeper.find(params[:id]) 
     Animal.transaction do 
      begin 
       @hippo.wash! 
       @bear.feed! # => FAIL AT THIS LINE 
       @zookeeper.finished_at = Time.now 
       @zookeeper.save! 
       redirect_to chores_completed_path 
      rescue Exception => e 
       render "new_chores" 
      end 
     end 
    end 
end 

如果Zookeeper#chores被调用且@bear.feed!失败并引发异常，那么将所有的回滚？

对于如何改进此代码的任何其他建议也是受欢迎的。

Answer 1

看来我必须做的是手动引发ActiveRecord :: Rollback，否则它将无法按预期工作。 ActiveRecord ::回滚是唯一一个不会导致你的屏幕转储。 http://api.rubyonrails.org/classes/ActiveRecord/Rollback.html

它是有道理的，它会这样工作，但不是真的我直觉上认为它会工作。如果我错了，请纠正我。

因此，新的代码将是这个样子：

class ZookeeperController < ApplicationController 

    def chores 
     @zookeeper = Zookeeper.find(params[:id]) 
     Animal.transaction do 
      begin 
       @hippo.wash! 
       @bear.feed! # => FAIL AT THIS LINE 
       @zookeeper.finished_at = Time.now 
       @zookeeper.save! 
       redirect_to chores_completed_path 
      rescue Exception => e 
       @_errors = true 
       render "new_chores" 
      end 
      raise ActiveRecord::Rollback if @_errors 
     end 
    end 
end