Paperclip- validate pdfs with content_type='application/octet-stream'

Question

I was using paperclip for file upload. with validations as below:

validates_attachment_content_type :upload, :content_type=>[\'application/pdf\

Answer 1

For paperclip 3.3 and Rails 3, I did this a bit differently

before_validation on: :create do   
  if media_content_type == 'application/octet-stream'
    mime_type = MIME::Types.type_for(media_file_name) 
    self.media_content_type = mime_type.first if mime_type.first  
  end
end

validates_attachment :media, content_type: { content_type: VALID_CONTENT_TYPES } 

By the way, i needed to do this because testing with Capybara and phantom js using attach_file did not generate the correct mime type for some files.