Paperclip renaming files after they're saved

Question

How do I rename a file after is has been uploaded and saved? My problem is that I need to parse information about the files automatically in order to come up with the file

Answer 1

To add to @Voyta's answer, if you're using S3 with paperclip:

(record.image.styles.keys+[:original]).each do |style|
  AWS::S3::S3Object.move_to record.image.path(style), new_file_path, record.image.bucket_name
end

record.update_attribute(:image_file_name, new_file_name)

Answer 2

Have you checked out paperclip interpolations?

If it is something that you can figure out in the controller (before it gets saved), you can use a combination of the controller, model, and interpolation to solve your problem.

I have this example where I want to name a file based on it's MD5 hash.

In my controller I have:

params[:upload][:md5] = Digest::MD5.file(file.path).hexdigest

I then have a config/initializers/paperclip.rb with:

Paperclip.interpolates :md5 do|attachment,style| 
  attachment.instance.md5
end

Finally, in my model I have:

validates_attachment_presence :upload
has_attached_file :upload,
  :path => ':rails_root/public/files/:md5.:extension',
  :url => '/files/:md5.:extension'

Answer 3

I'd like to donate my "safe move" solution that doesn't rely on any private API and protects against data loss due to network failure:

First, we get the old and new paths for every style:

styles = file.styles.keys+[:original]
old_style2key = Hash[ styles.collect{|s| [s,file.path(s).sub(%r{\A/},'')]} ]
self.file_file_name = new_filename
new_style2key = Hash[ styles.collect{|s| [s,file.path(s).sub(%r{\A/},'')]} ]

Then, we copy every file to it's new path. Since the default path includes both object ID and filename, this can never collide with the path for a different file. But this will fail if we try to rename without changing the name:

styles.each do |style|
  raise "same key" if old_style2key[style] == new_style2key[style]
  file.s3_bucket.objects[old_style2key[style]].copy_to(new_style2key[style])
end

Now we apply the updated model to the DB:

save!

It is important to do this after we create the new S3 objects but before we delete the old S3 objects. Most of the other solutions in this thread can lead to a loss of data if the database update fails (e.g. network split with bad timing), because then the file would be at a new S3 location but the DB still points to the old location. That's why my solution doesn't delete the old S3 objects until after the DB update succeeded:

styles.each do |style|
  file.s3_bucket.objects[old_style2key[style]].delete
end

Just like with the copy, there's no chance that we accidentally delete another database object's data, because the object ID is included in the path. So unless you rename the same database object A->B and B->A at the same time (e.g. 2 threads), this delete will always be safe.

Answer 4

If, for example, your model has attribute image:

has_attached_file :image, :styles => { ...... }

By default papepclip files are stored in /system/:attachment/:id/:style/:filename.

So, You can accomplish it by renaming every style and then changing image_file_name column in database.

(record.image.styles.keys+[:original]).each do |style|
    path = record.image.path(style)
    FileUtils.move(path, File.join(File.dirname(path), new_file_name))
end

record.image_file_name = new_file_name
record.save

Answer 5

My avatar images are named with the user slug, if they change their names I have to rename images too.

That's how I rename my avatar images using S3 and paperclip.

class User < ActiveRecord::Base
  after_update :rename_attached_files_if_needed

  has_attached_file :avatar_image,
    :storage        => :s3,
    :s3_credentials => "#{Rails.root}/config/s3.yml",
    :path           => "/users/:id/:style/:slug.:extension",
    :default_url    => "/images/users_default.gif",
    :styles         => { mini: "50x50>", normal: "100x100>", bigger: "150x150>" }

  def slug
    return name.parameterize if name
    "unknown"
  end


  def rename_attached_files_if_needed
    return if !name_changed? || avatar_image_updated_at_changed?
    (avatar_image.styles.keys+[:original]).each do |style|
      extension = Paperclip::Interpolations.extension(self.avatar_image, style)
      old_path = "users/#{id}/#{style}/#{name_was.parameterize}#{extension}"
      new_path = "users/#{id}/#{style}/#{name.parameterize}#{extension}"
      avatar_image.s3_bucket.objects[old_path].move_to new_path, acl: :public_read
    end
  end
end

Answer 6

And to add yet another answer, here is the full method I'm using for S3 renaming :

  def rename(key, new_name)
    file_name = (key.to_s+"_file_name").to_sym
    old_name = self.send(file_name)
    (self.send(key).styles.keys+[:original]).each do |style|
      path = self.send(key).path(style)
      self[file_name] = new_name
      new_path = self.send(key).path(style)
      new_path[0] = ""
      self[file_name] = old_name
      old_obj = self.send(key).s3_object(style.to_sym)
      new_obj = old_obj.move_to(new_path)
    end
    self.update_attribute(file_name, new_name)
  end

To use : Model.find(#).rename(:avatar, "test.jpg")