Copies S3-stored Paperclip attachments from one AR model to another

copy_attachments.rb

# lib/paperclip/copy_attachments.rb

# Copies S3-stored Paperclip attachments from one AR model to another.
#
# This module should be mixed into the target AR model.

if Gem::Version.new(::AWS::VERSION) >= Gem::Version.new(2)
  raise NotImplementedError, 'coded for aws-sdk v1'
end


module Paperclip
  module CopyAttachments

    # Copies S3-stored attachments from the source ActiveRecord instance.
    def copy_attachments_from(source)
      self.class.attachment_definitions.keys.each do |attachment_name|
        source_attachment = source.send attachment_name

        next if source_attachment.blank?
        next if source_attachment.options[:storage] != :s3

        destination_attachment = send attachment_name

        [:original, *destination_attachment.styles.keys].uniq.map do |style|
          Paperclip.log "S3 copy: #{source_attachment.path(style)} -> #{destination_attachment.path(style)}"

          source_s3_object = source_attachment.s3_object style
          destination_s3_object = destination_attachment.s3_object style

          source_s3_object.copy_to destination_s3_object, acl: source_attachment.s3_permissions(style)
        end
      end
    end

  end
end

paperclip.rb

# config/initializers/paperclip.rb

require 'paperclip/copy_attachments'
ActiveRecord::Base.send :include, Paperclip::CopyAttachments