How to reassign uploaded files to some other models rails 3.1 - ruby-on-rails-3

Question

I have a scenario where i am uploading files dynamically using ajax remotipart, then later i assign those uploaded files to any model. I have such settings in uploader.
class DocumentUploader < CarrierWave::Uploader::Base
storage :file
def store_dir
"uploads/#{model.class.to_s.pluralize.underscore}/#{model.documentable_type.to_s.pluralize.underscore}/#{model.documentable_id}"
end
def extension_white_list
%w(doc pdf docx xls xlsx)
end
end
class Document < ActiveRecord::Base
mount_uploader :document, DocumentUploader
belongs_to :documentable, :polymorphic => true
validates :document, :presence => true
validates :description, :presence => true
end
class Post < ActiveRecord::Base
has_many :documents, :as=>:documentable
end
When i upload a document without providing documentable source, it uploads the files to /uploads/documents/uploaded_file.doc
But when i assign that document to some other model like
#post = Post.first
#post.documents << Document.last
#post.save
It save the record correctly and when get url of the file like #post.documents.first.document.url it gave url like this /uploads/documents/posts/10212/uploaded_file.doc where the file was not available.
How can i handle such assignment of pre-existing uploads?

Answer 1

I came here while googling and thought some people might help this piece of code I'm using in a controller to re-assign a file (here it's an image) to another model which is handled with CarrierWave:
def create
temporary_image = TemporaryImage.find(params[:temporary_image][:id])
#player = Player.new(params[:player])
#player.image = File.open(temporary_image.image.current_path)
# now you can handle #player.image as if it was
# originally assigned by CarrierWave
end
where
class Player < ActiveRecord::Base
attr_accessible :image
mount_uploader :image, PlayerImageUploader
end
and
class TemporaryImage < ActiveRecord::Base
attr_accessible :image
mount_uploader :image, TemporaryImageUploader
end
I'm using this in conjunction with an ajax fileupload (stored via TemporaryImage) where the image is immediately presented and can then be cropped. After cropping it is stored within Player.

Answer 2

I solved the issue by doing lot of hit and trail. but finally solved.
class Document < ActiveRecord::Base
mount_uploader :document, DocumentUploader
belongs_to :documentable, :polymorphic => true
validates :document, :presence => true
validates :description, :presence => true
after_update :relocate_files
def relocate_files
src_file = Rails.root.join("public", "uploads", "documents", document.url.split("/").last)
dst_file = Rails.root.join("public", "uploads", "documents", documentable_type.pluralize.underscore, documentable_id.to_s, document.url.split("/").last)
unless FileTest.exists?(dst_file)
FileUtils.mkdir_p(File.dirname(dst_file))
FileUtils.mv(src_file, dst_file)
end
end
end