Rails 3 Custom Class Question

I am trying to create a separate model class for image uploading, which was previously in the object's controller. I also want to make it agnostic, so I can upload images using one class from multiple objects.

In my original object's model class, I have the following now:

class Object < ActiveRecord::Base
  after_save :photo_store
  delegate :has_photo?, :photo, :photo_path, :store_photo, :photo_filename, :to => :photo_store

  def photo_store
    PhotoStore.new(self)
  end
end

Then, the PhotoStore class looks like this:

class PhotoStore
  attr_reader :object

  def initialize(object)
    @object = object
  end

  def photo=(file_data)
    unless file_data.blank?
      @file_data = file_data
      self.extension = file_data.original_filename.split('.').last.downcase
    end
  end

  PHOTO_STORE = File.join RAILS_ROOT, 'public', 'photo_store'

  def photo_filename
    File.join PHOTO_STORE, "#{id}.#{extension}"
  end

  def photo_path
    "/photo_store/#{id}.#{extension}"
  end

  def has_photo?
    File.exists? photo_filename
  end

  private

  def store_photo
    if @file_data
      FileUtils.mkdir_p PHOTO_STORE
      File.open(photo_filename, 'wb') do |f|
        f.write(@file_data.read)
      end
    end
  end
end

However, this throws the error below when I try and use the has_photo? method in the object's view.

undefined local variable or method `id' for #

Do I need to put some other type of relationship in place between the Object and PhotoStore?

And a separate question: What's the best way to make this agnostic? Since it uses just the ID of the object, I could just include the Object's name in the filename, but is th开发者_开发技巧at the best way to do it?

Thanks!

Because at File.join PHOTO_STORE, "#{id}.#{extension}" you call method PhotoStore#id, but it does not exists.

You should do that

File.join PHOTO_STORE, "#{@object.id}.#{@object.extension}"