Carrierwave filename keeps changing on update_attributes

Question

I have model Company and company has mounted carrierwave uploader Logo.

class Company < ActiveRecord::Base
  mount_uploader :logo, LogoUploader

Images upload works, but I have an issue with update_attributes. When user wants to update only description or title of the company, but not to upload new image - filename value in DB is still being changed every time. Here is a simple example:

1.9.3-p545 :004 > a = Company.last
1.9.3-p545 :005 > a.update_attributes(:title => "test title 2")
 (0.4ms)  BEGIN
  Company Exists (0.9ms)  SELECT 1 AS one FROM `companies` WHERE (`companies`.`title` = BINARY 'test title 2' AND `companies`.`id` != 37) LIMIT 1
  Company Load (0.7ms)  SELECT `companies`.* FROM `companies` WHERE `companies`.`id` = 37 LIMIT 1
   (0.7ms)  UPDATE `companies` SET `title` = 'test title 2', `logo` = '1396206630_1f288be4.jpg', `updated_at` = '2014-03-30 19:10:30' WHERE `companies`.`id` = 37
   (8.1ms)  COMMIT
 => true 

Why logo is being updated here with new value even the new value was not given? How to avoid this?

Phillipphillipe

filename value in DB is still being changed every time with a new filename or existing file name? What is the original file name before updating? Do you mean that 1396206630_1f288be4.jpg is a new file name? – Apotheosize

With new file name. Although no new file was uploaded. – Phillipphillipe

Answer 1

I experienced the same and figured it out that an uploader class' filename method should not set a new filename unless original_filename presents. CarrierWave has a relevant wiki page about filename which doesn't directly address this issue, but is enough to get a clue.

For example,

This code changes the filename field every time the model is updated.

class SampleUploader < CarrierWave::Uploader::Base
  def filename
    "#{Time.now.strftime('%Y%m%d%H%M%S')}.jpg"
  end
end

However this extra if statement prevents the former behaviour.

class SampleUploader < CarrierWave::Uploader::Base
  def filename
    "#{Time.now.strftime('%Y%m%d%H%M%S')}.jpg" if original_filename.present?
  end
end

Mattress

This should be the accepted answer. Worked for me. Nonetheless it's weird that carrierwave fires this filename method every time the record gets updated. – Chorus