Randomize filenames for paperclip upload

Ruby on Rails
1

I transitioned from carrierwave to paperclip last week and am having trouble randomizing the filename of an upload. I had a custom method from carrierwave that took care of this, but can’t find the equivalent in paperclip.

I have a Logo model with photo attachment and store the files in a single directory. I found an article on the wiki about normalizing filenames, but that isn’t the same thing. Any help would be appreciated.

2

Here’s the attachment definition that did this for me on my last project:

  has_attached_file :file,
    styles: { large: '620x410>' },
    convert_options: { all: '-strip' },
    s3_permissions: { original: :private },
    s3_headers: {
      'Cache-Control' => 'max-age=315576000',
      'Expires' => 10.years.from_now.httpdate
    },
    path: 'public/system/:class/:hash.:extension',
    url: '/system/:class/:hash.:extension',
    hash_secret: 'really-long-random-generated-string-not-publicly-accessible'

The key is the :hash interpolation and the :hash_secret argument. Here’s the bit from the readme on this: GitHub - thoughtbot/paperclip: Easy file attachment management for ActiveRecord

3

Thank you. I think I was misunderstanding the obfuscation section of the docs, thinking it still stored the original filename in the database. Is there an easy way I can shorten the hash?

This doesn’t work, but something like this? :hash[0..9].:extension

Update:
Taking a closer look, paperclip does store the original filename in the database, and a hashed version on s3. Unfortunately this will not work for my case as I am trying to randomize the filename stored in the database. Sorry for not making that point clearer.

Final Update:
Going back to the Wiki, under helpful articles, an article for normalizing filenames, referenced another article for randomizing filenames stored in the database.

So in the end, I followed that and added a private method and before_create method.

  def randomize_file_name
    extension = File.extname(photo_file_name).downcase
    self.photo.instance_write(:file_name, "lgo#{Digest::SHA1.hexdigest((rand(12123123423) * Time.now.to_i).to_s)[0..9]}#{extension}")
  end

This is now working as expected and now I also understand more about the interpolations. Both are useful to know depending on what your needs are. I should have dug deeper into the wiki.