Question

我有模型Student和控制器StudentsController。

我在控制器中有这个代码：

def create_students_list
   @students=[...#some code which evaluates to array of student instances]
  result=list_transaction(@students)
  ...
  end 
      private
        def list_transaction(collection, options= {})
          errors=[]
          ActiveRecord::Base.transaction do
           collection.each do |item|
            if item.save
             else
             errors << item.errors
            end
           end
          end
        if errors.any?
        {:success=>false, :errors => errors }
        else
       {:success => true}
      end
     end

这个想法是：我有大量的输入，我想在交易中包装。还有一些其他逻辑，而不是这里的问题。但我想要DRY控制器，我也需要其他控制器的相同操作，所以我决定使用PORO方法：拥有可以重用的纯Ruby对象。

   class List
    include ActiveRecord
    include ActiveRecord::Transactions::ClassMethods

    def initialize(collection)
     @collection=collection
    end

    def group_input
     outputs={:valid=>[], :invalid=>[]}
     @collection.each do |element|
      if element.valid?
       outputs[:valid] << element
       else
       outputs[:invalid] << [element, element.errors]
       end
      end
    if outputs[:valid].any?
     save_list(outputs[:valid])
     outputs[:something_saved]=true
     outputs[:valid].delete
    end
     save_list(outputs[:valid])
    if outputs[:invalid].empty?
     outputs = {}
     outputs[:all_records_saved]=true
    else
     outputs=outputs[:invalid]
    end
     outputs
    end

    private
    def save_list(collection)
     ActiveRecord::Base transaction do
      collection.each do |element|
      element.save
      end
    end
    end
  end

问题：它会导致错误：

NameError:
       undefined local variable or method `connection' for #<List:0x000001073a62d8 @collection=[#<Student id: nil>]>

尝试使用ActiveRecord :: ConnectionsHandler，这也引发了：

 NameError:
       undefined local variable or method `connection_handler' for #<List:0x0000010c285480 @collection=[#<Student id: nil>]>

我不知道如何使这个工作

Answer 1

您似乎还需要包含其他ActiveModel类

class List
  include ActiveRecord::Base.transaction

  extend ActiveModel::Naming
  include ActiveModel::Conversion
  include ActiveModel::Validations

  #... rest of the code
end

ActiveRecord和PORO方法

1 个答案: