CarrierWave: Create the same, unique filename for all versioned files

Question

Before I go into detail I\'ll get right to the point: has anyone figured out a way to get Carrierwave to save files with their names as a timestamp or any arbitrary string that

Answer 1

You can do something like this in your uploader file, and it will also work for versioned files (i.e. if you have one image and then create 3 other thumbnail versions of the same file, they will all have the same name, just with size info appended onto the name):

  # Set the filename for versioned files
  def filename
    random_token = Digest::SHA2.hexdigest("#{Time.now.utc}--#{model.id.to_s}").first(20)
    ivar = "@#{mounted_as}_secure_token"    
    token = model.instance_variable_get(ivar)
    token ||= model.instance_variable_set(ivar, random_token)
    "#{model.id}_#{token}.jpg" if original_filename
  end

This will create a filename like this for example: 76_a9snx8b81js8kx81kx92.jpg where 76 is the model's id and the other bit is a random SHA hex.

Answer 2

The solution is the same as described in the official documentation

But it always returns original_filename as nil. So just change it to instance variable as @original_filename.present?

Answer 3

Check also the solution from carrierwave wiki available now https://github.com/carrierwaveuploader/carrierwave/wiki/How-to:-Use-a-timestamp-in-file-names

You can include a timestamp in filenames overriding the filename as you can read in Carrierwave docs:

 class PhotoUploader < CarrierWave::Uploader::Base
     def filename
       @name ||= "#{timestamp}-#{super}" if original_filename.present? and 
       super.present?
    end

   def timestamp
     var = :"@#{mounted_as}_timestamp"
     model.instance_variable_get(var) or model.instance_variable_set(var, Time.now.to_i)
   end
 end

Don't forget to memorize the result in an instance variable or you might get different timestamps written to the database and the file store.