ruby-on-rails - 如何使用 Rails Paperclip 处理包含非字母数字字符的文件名

Question

我正在使用带有 Paperclip + Rails 的 Rails 3:

Gemfile
  gem "paperclip"
  gem "mongoid-paperclip", require: 'mongoid_paperclip'

除非用户上传文件名中包含非字母数字字符的照片，否则一切正常:

thing 1/2/3/.PNG

我已经尝试用 before_post_process before_validation 处理这个:

  def strip_strange_characters_from_attachments
    # Set the clean Attachment File Title
    self.attachment.instance.meta['file_name'] = "test.png"
  end

但是 Rails 事先出错并且文件没有上传。错误如下。有什么想法吗？

[2014-06-10 13:54:47] INFO    Command :: identify -format %wx%h '/var/folders/g_/kythn1dx4fbbry5npb4jx1cr0000gn/T/thing 1:2:3:20140610-41978-ksy5e9.PNG[0]'
[2014-06-10 13:54:47] INFO    [paperclip] An error was received while processing: #<Paperclip::Errors::NotIdentifiedByImageMagickError: /var/folders/g_/kythn1dx4fbbry5npb4jx1cr0000gn/T/thing 1:2:3:20140610-41978-ksy5e9.PNG is not recognized by the 'identify' command.>
[2014-06-10 13:54:47] INFO    Command :: identify -format %wx%h '/var/folders/g_/kythn1dx4fbbry5npb4jx1cr0000gn/T/thing 1:2:3:20140610-41978-ksy5e9.PNG[0]'
[2014-06-10 13:54:47] INFO    [paperclip] An error was received while processing: #<Paperclip::Errors::NotIdentifiedByImageMagickError: /var/folders/g_/kythn1dx4fbbry5npb4jx1cr0000gn/T/thing 1:2:3:20140610-41978-ksy5e9.PNG is not recognized by the 'identify' command.>
[2014-06-10 13:54:47] INFO    Command :: identify -format %wx%h '/var/folders/g_/kythn1dx4fbbry5npb4jx1cr0000gn/T/thing 1:2:3:20140610-41978-ksy5e9.PNG[0]'
[2014-06-10 13:54:47] INFO    Completed 422 Unprocessable Entity in 120.0ms
[2014-06-10 13:54:48] INFO    Mongo: (1.5333ms) | Query count: 3
[2014-06-10 13:54:48] FATAL   
Mongoid::Errors::Validations - 
Problem:
  Validation of Mongo::Attachment failed.
Summary:
  The following errors were found: Attachment /var/folders/g_/kythn1dx4fbbry5npb4jx1cr0000gn/T/thing 1:2:3:20140610-41978-ksy5e9.PNG is not recognized by the 'identify' command., Attachment /var/folders/g_/kythn1dx4fbbry5npb4jx1cr0000gn/T/thing 1:2:3:20140610-41978-ksy5e9.PNG is not recognized by the 'identify' command.
Resolution:

关于处理这个错误有什么想法/建议吗？

Answer 1

mongoid-paperclip gem 只是将所有给定的选项传递给 paperclip(请参阅 source)，因此您需要清理文件名，就像使用普通回形针时一样。

有两个选项可以实现这一点，这里是默认值:

 :restricted_characters => /[&$+,\/:;=?@<>\[\]\{\}\|\\\^~%# ]/, 
 :filename_cleaner => nil,

通常情况下，文件名中的空格完全没问题，但您可以尝试将其添加到 :restricted_characters 中。限制字符用于初始化 PaperClip::FilenameCleaner。

has_mongoid_attached_file :image, restricted_characters: /[\s&$+,\/:;=?@<>\[\]\{\}\|\\\^~%# ]/ 

您可以更明确地指定一个文件名清理器，如下所示(但不确定这是否相关)。

has_mongoid_attached_file :image, filename_cleaner: Paperclip::FilenameCleaner.new(/[\s&$+,\/:;=?@<>\[\]\{\}\|\\\^~%# ]/)

这与指定 restricted_characters 选项完全相同。但是，您可以使用此选项并将您自己的 FilenameClear 版本传递给它。它应该有一个 call 方法并将文件名作为参数接收(参见 source )