Working with Paperclip images before save

I'm saving an image upload using Paperclip in Rails, which is working fine.

  has_attached_file :image, :styles =&开发者_如何转开发gt; {
    :small => "80x90#"
  }

What I would to is then save a copy of the small image as a base64 encoded string in the model, when the model is created.

  before_update :encode_image
  
  private
  
  def encode_image
    self.base64 = ActiveSupport::Base64.encode64(open(self.image.path(:small)).to_a.join)
  end

The code above works a treat on update, if the image has previously been saved. I would to apply this logic to a callback that fires before the model saves, but after the images have been processed.

I had thought that after_post_process would be my saviour, but the path is not fully formed at the point (missing the id).

What am I missing?

Rich

Workaround

My workaround has been to do the following, but it seems a shame run that encode routine every time you update the model:

  after_save :encode_image
  
  private
  
  def encode_image
    unless self.image.path(:small).blank?
      b64 = ActiveSupport::Base64.encode64(open(self.image.path(:small)).to_a.join)
      unless self.base64 == b64
        self.update_attribute :base64, b64
      end
    end
  end

My workaround has been to do the following, but it seems a shame run that encode routine every time you update the model:

  after_save :encode_image

  private

  def encode_image
    unless self.image.path(:small).blank?
      b64 = ActiveSupport::Base64.encode64(open(self.image.path(:small)).to_a.join)
      unless self.base64 == b64
        self.update_attribute :base64, b64
      end
    end
  end