paper_trail 2

一些‘选择’

你可以让paper_trail ‘忽略’ 一些改动，不记录它，比如 ‘忽略’ create :

class Article < ActiveRecord::Base
  has_paper_trail :on => [:update, :destroy] # 通过 on 选项
end

或者 ‘何时’ 才生成一个新版本 ‘version’

  has_paper_trail :if     => Proc.new { |t| t.language_code == 'US' },
  # 通过 if 或 unless 选项
  has_paper_trail :if     => Proc.new { |t| t.language_code == 'US' },
                  :unless => Proc.new { |t| t.type == 'DRAFT'       }
end

再或者是 ‘忽略’ 一些不想 ‘跟踪’ 的属性：

class Article < ActiveRecord::Base
  has_paper_trail :ignore => [:title, :rating] # 通过 ignore
end

与上面的 ignore 相反，你可以‘只跟踪’自己 ‘指定’ 的属性

class Article < ActiveRecord::Base
  has_paper_trail :only => [:title] # 通过 only
end

从一开始就 ‘忽略’ 一些 属性(区别于上面的各个‘选项’)

class Article < ActiveRecord::Base
  has_paper_trail :skip => [:file_upload] # 用 skip
end