Overriding content_type for Rails Paperclip plugin
- by Fotios
I think I have a bit of a chicken and egg problem.  I would like to set the content_type of a file uploaded via Paperclip.  The problem is that the default content_type is only based on extension, but I'd like to base it on another module.
I seem to be able to set the content_type with the before_post_process
class Upload < ActiveRecord::Base 
  has_attached_file :upload
  before_post_process :foo
  def foo
    logger.debug "Changing content_type"
    #This works
    self.upload.instance_write(:content_type,"foobar")
    # This fails because the file does not actually exist yet
    self.upload.instance_write(:content_type,file_type(self.upload.path)
  end
  # Returns the filetype based on file command (assume it works)
  def file_type(path)
    return `file -ib '#{path}'`.split(/;/)[0]
  end
end
But...I cannot base the content type on the file because Paperclip doesn't write the file until after_create.
And I cannot seem to set the content_type after it has been saved or with the after_create callback (even back in the controller)
So I would like to know if I can somehow get access to the actual file object (assume there are no processors doing anything to the original file) before it is saved, so that I can run the file_type command on that.  Or is there a way to modify the content_type after the objects have been created.