Paperclip Get dirty file before update

Question

Background:

I'm developing Rails Application and in some models I'm using paperclip gem to save attachments. In same models I'm using public_activity gem to track the model changes & I've prepared Restore functionality based on that to be able to Undo changes on that model with specific conditions. Now using paperclip option :preserve_files => true it's simple to get the old file in case of delete, but in case of update, I don't know how.

Question:

public_activity gem is already using before_action callback and I can handle all dirty fields except Paperclip file update. So how can I get the dirty updated file without changing my models or adding extra callbacks (because I'm using this achievement in multiple models and Undo functionality is generic).

Note:

I'm using File.exist?(paperclip_attachment.path) to check whether the file is still exist or no, and it returns false in case of update callback of public_activity (I think it is same as before_update callback).

Answer 1

I've did a simple way to get the dirty file with just edit Undo Functionality in public_activity update callback:

dirty_file_path = Dir.glob(File.join(File.dirname(paper_clip_attachment.path), '*.*')).max { |a,b| File.ctime(a) <=> File.ctime(b) }

paper_clip_attachment.path includes the path to the file, but the file itself is not yet created.

The code above just checks the container folder of the file paper_clip_attachment.path then checks the latest created file and save it's path to be used in Undo step.