Paperclip - Validate File Type but not Presence

Question

I am using paperclip to handle my file uploads, and in one situation I don't want the file to be mandatory. I do however want to make sure it is a specific file type when it is present.

I have this:

class TestModel < ActiveRecord::Base
    #stuff
    has_attached_file :sound #etc...
    validates_attachment_content_type :sound, :content_type => ['audio/mp3', 'application/x-mp3']
end

And when I have no sound file present, it tells me it is not one of the valid content types. I've tried adding '' to the :content_type array, which also doesn't work!

I also attempted creating a lambda procedure for the :if property, but I can't get it to run without some kind of error.

Anything missing here?

Answer 1

Hi, chunk of my model:

  has_attached_file :logo, :styles => { :medium => ["300x300>", :png], :thumb => ["100x100>", :png] }
  validates_attachment_size :logo, :less_than => 2.megabytes
  validates_attachment_content_type :logo, :content_type => ['image/jpeg', 'image/png', 'image/gif']

and if I provide no image file, @obj.update_attributes(..) raises no error, but validates if I provide a file. Maybe you use older version of paperclip?

gem list | ack paperclip
paperclip (2.3.1.1)

Answer 2

Hi, I guess you could try a 'conditional validation' where the condition is if a file is present?

class TestModel < ActiveRecord::Base
  #stuff
  has_attached_file :sound #etc...
  validates_attachment_content_type :sound, :content_type => ['audio/mp3', 'application/x-mp3'], :if => :sound_attached?

  def sound_attached?
    self.sound.file?
  end
end