Rails 3 Transactions，回滚所有内容

问题描述

||

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

被调用而

@bear.Feed!

失败并引发异常，那么一切都会回滚吗？ 也欢迎任何其他有关如何改进此代码的建议。     

解决方法

        看来我要做的是手动提高ActiveRecord :: Rollback，否则它将无法按预期工作。 ActiveRecord :: Rollback是不会导致屏幕转储的唯一选项。 http://api.rubyonrails.org/classes/ActiveRecord/Rollback.html 它可以像这样工作是有道理的，但是我并不是直觉上认为它会工作。如果我错了，请纠正我。 因此，新代码如下所示：

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