Question

我有遗留数据库
我想用paperclip gem上传图片
回形针需要四个工作参数但我只有一个字段，即文件名，所有参数都不在数据库中那么如何使用单个参数来集成回形针以下是我在模型中的代码

class ItemMaster < ActiveRecord::Base

  set_table_name "MDIMT"

  attr_accessible :IMTNAME, :IMTBRIEFDESC, :IMTDETAILDESC, :IMTIMAGE, :IMTCALORIE, :IMTIMTEMCODE1, :IMTIMTEMCODE2,
                  :IMTPRICE, :IMTISVARPRICE, :IMTISCUSTOMIZED, :IMTDURATIONMINS, :IMTSEQNUM, :CREATEDBY, :MODIFIEDBY, 
                  :CREATEDATE, :MODIFYDATE, :EXTRAFIELD1, :EXTRAFIELD2, :EXTRAFIELD3, :EXTRAFIELD4, :IMTISACTIVE, :IMTTAX1,
                  :IMTTAX2, :IMTTAX3, :IMTTAX4, :IMTCNDITEMTYPE, :IMTCNDFILTEROPT
  alias_attribute :image_file_name, :IMTIMAGE  
  has_attached_file :image,
                    :path => ":rails_root/public/assets/:basename.:extension",
                    :url => "/assets/images/:basename.:extension" 
end

Answer 1

Paperclip使用标准的getter和setter来存储或接收来自实例的值。您尝试重载getter和setter，然后将数据存储在序列化哈希中：

class ItemMaster < ActiveRecord::Base
  set_table_name "MDIMT"

  attr_accessible :IMTNAME, :IMTBRIEFDESC, :IMTDETAILDESC, :IMTIMAGE, :IMTCALORIE, :IMTIMTEMCODE1, :IMTIMTEMCODE2,
                  :IMTPRICE, :IMTISVARPRICE, :IMTISCUSTOMIZED, :IMTDURATIONMINS, :IMTSEQNUM, :CREATEDBY, :MODIFIEDBY, 
                  :CREATEDATE, :MODIFYDATE, :EXTRAFIELD1, :EXTRAFIELD2, :EXTRAFIELD3, :EXTRAFIELD4, :IMTISACTIVE, :IMTTAX1,
                  :IMTTAX2, :IMTTAX3, :IMTTAX4, :IMTCNDITEMTYPE, :IMTCNDFILTEROPT

  alias_attribute   :image_hash, :IMTIMAGE
  default_value_for :image_hash, {}
  serialize         :image_hash, Hash

  has_attached_file :image,
                    :path => ":rails_root/public/assets/:basename.:extension",
                    :url => "/assets/images/:basename.:extension"

  %w[ image_file_name image_file_size image_content_type image_processing image_updated_at ].each do |field|

    # Adds getter and setter for all keys in the array and stored the data in the image_hash instead
    class_eval <<-END_OF_RUBY, __FILE__, __LINE__ + 1

      def #{field}
        image_hash['#{field}']
      end

      def #{field}=(value)
        self.image_hash['#{field}'] = value
      end

    END_OF_RUBY
  end
end

带有旧数据库的回形针

1 个答案: