Paperclip renaming files after they're saved

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 name the file should be saved as with my application, but I can't access the information required to generate the file name till the record for the model has been saved.

Another option is set to default, work for all upload.

This example change name file to 'name default' for web, example: `test áé.jpg` to `test_ae.jpg`

**helper/application_helper.rb**

def sanitize_filename(filename)
fn = filename.split /(?<=.)\.(?=[^.])(?!.*\.[^.])/m
fn[0] = fn[0].parameterize
return fn.join '.'
end


Create **config/initializers/paperclip_defaults.rb**

include ApplicationHelper

Paperclip::Attachment.default_options.update({
:path => ":rails_root/public/system/:class/:attachment/:id/:style/:parameterize_file_name",
:url => "/system/:class/:attachment/:id/:style/:parameterize_file_name",
})

Paperclip.interpolates :parameterize_file_name do |attachment, style|
sanitize_filename(attachment.original_filename)
end

Need restart, after put this code

The following migration solved the problem to me.

**Renaming `avatar` to `photo`**:

class RenamePhotoColumnFromUsers < ActiveRecord::Migration
def up
add_attachment :users, :photo

# Add `avatar` method (from Paperclip) temporarily, because it has been deleted from the model
User.has_attached_file :avatar, styles: { medium: '300x300#', thumb: '100x100#' }
User.validates_attachment_content_type :avatar, content_type: %r{\Aimage\/.*\Z}

# Copy `avatar` attachment to `photo` in S3, then delete `avatar`
User.where.not(avatar_file_name: nil).each do |user|
say "Updating #{user.email}..."

user.update photo: user.avatar
user.update avatar: nil
end

remove_attachment :users, :avatar
end

def down
raise ActiveRecord::IrreversibleMigration
end
end

Hope it helps :)

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.

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

To add to @Fotios's answer:

its the best way I think to make custom file name, but in case you want file name based on md5 you can use fingerprint which is already available in Paperclip.

All you have to do is to put this to config/initializers/paperclip_defaults.rb

Paperclip::Attachment.default_options.update({
# :url=>"/system/:class/:attachment/:id_partition/:style/:filename"
:url=>"/system/:class/:attachment/:style/:fingerprint.:extension"
})

There's no need to set :path here as by default it's made that way:

:path=>":rails_root/public:url"

I didn't check if it's necessary but in case it doesn't work for you make sure your model is able to save fingerprints in the database -> [here][1]

One more tip which I find handy is to use rails console to check how it works:

$ rails c --sandbox
> Paperclip::Attachment.default_options
..
> s = User.create(:avatar => File.open('/foo/bar.jpg', 'rb'))
..
> s.avatar.path
=> "/home/groovy_user/rails_projectes/funky_app/public/system/users/avatars/original/49332b697a83d53d3f3b5bebce7548ea.jpg"
> s.avatar.url
=> "/system/users/avatars/original/49332b697a83d53d3f3b5bebce7548ea.jpg?1387099146"






[1]:

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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)

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")

Have you checked out [paperclip interpolations][1]?

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'



[1]:

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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