PaperTrail不适合使用Carrierwave和“remove_previously_stored_after_update”选项。

I need to version images for my Rails app. I'm using Carrierwave for file uploads, and PaperTrail for versioning.

我需要为我的Rails应用版本的图像。我使用Carrierwave文件上传，和PaperTrail进行版本控制。

While versioning seems to work pretty well, it seems though that reifying a version doesn't play nice with Carrierwave's remove_previously_stored_files_after_update config deactivated: in this situation, a simple reload of the reified model instance doesn't work anymore, only an explicit fresh load from the database (using Model.find 123) works.

虽然版本控制看起来运行得很好，但是似乎对一个版本的具体化并不适合Carrierwave的remove_previously_stored_files_after_update配置被停用:在这种情况下，一个简单的重新加载的具体化的模型实例不再工作了，只有一个来自数据库的显式的新加载(使用模型)。发现123)的作品。

I have created a demo Rails app to demonstrate the problem.

我创建了一个演示Rails应用来演示这个问题。

The User model mounts two uploaders:

用户模型安装两个上传者:

• AvatarUploader, which removes the file after update (default)
• AvatarUploader，在更新后删除文件(默认)
• KeepingFilesAvatarUploader, which doesn't remove the file after update, using the remove_previously_stored_files_after_update option set to false
• KeepingFilesAvatarUploader，它不会在更新后删除文件，使用remove_previously_stored_files_after_update选项设置为false。

Code of AvatarUploader:

AvatarUploader代码:

# encoding: utf-8

class AvatarUploader < CarrierWave::Uploader::Base
  storage :file

  def store_dir
    "uploads/#{model.class.to_s.underscore}/#{model.id}/#{mounted_as}"
  end
end

Code of KeepingFilesAvatarUploader:

KeepingFilesAvatarUploader代码:

# encoding: utf-8

class KeepingFilesAvatarUploader < CarrierWave::Uploader::Base
  storage :file

  def store_dir
    "uploads/#{model.class.to_s.underscore}/#{model.id}/#{mounted_as}"
  end

  configure do |config|
    config.remove_previously_stored_files_after_update = false
  end
end

The only difference is the remove_previously_stored_files_after_update option.

惟一的区别是remove_previously_stored_files_after_update选项。

Here's the code of the User model:

下面是用户模型的代码:

class User < ActiveRecord::Base
  has_paper_trail only: [:name, :avatar, :keeping_files_avatar]
  mount_uploader :avatar, AvatarUploader
  mount_uploader :keeping_files_avatar, KeepingFilesAvatarUploader
end

I have written some specs which demonstrate the unexpected behaviour. As they are a bit long to post, see here:

我已经写了一些说明这种意外行为的规范。因为他们有点长，所以在这里看到:

https://github.com/jmuheim/test-carrierwave-papertrail/blob/master/spec/models/user_spec.rb#L20

https://github.com/jmuheim/test-carrierwave-papertrail/blob/master/spec/models/user_spec.rb活用

All specs pass except the one that I set to pending, here's the output:

所有的规格通过，除了我设置的待定，这里是输出:

  1) User versioning reloading the model after reify sets "keeping_files_avatar" to the original value
     # See http://*.com/questions/29624223/papertrail-doesnt-play-nice-with-carrierwave-and-remove-previously-stored-file
     Failure/Error: expect(user.keeping_files_avatar.file.filename).to eq 'original-image.jpg' # This upload field isn'! <<<FAILING LINE>>>!

       expected: "original-image.jpg"
            got: "new-image.jpg"

       (compared using ==)
     # ./spec/models/user_spec.rb:20:in `block (4 levels) in <top (required)>'

Finished in 0.20704 seconds (files took 1.51 seconds to load)
4 examples, 0 failures, 1 pending

It would be really nice to get this to work. I don't need this functionality right now, but I don't want to add any technical debt to my project (especially this one could lead to very unforeseen problems as one usually relies on simply doing a reload on a model to refresh its attributes).

把它弄出来会很好。我现在不需要这个功能，但是我不想在我的项目中添加任何技术债务(特别是这一项可能会导致非常难以预料的问题，因为通常情况下，一个人仅仅依靠在模型上重新加载来刷新它的属性)。

1 个解决方案

#1

Check if this will work for you

检查一下是否适合你。

class User < ActiveRecord::Base
  has_paper_trail only: [:name, :avatar, :keeping_files_avatar]

  mount_uploader :avatar, AvatarUploader
  mount_uploader :keeping_files_avatar, KeepingFilesAvatarUploader

  skip_callback :save, :after, :remove_previously_stored_keeping_files_avatar
end