ruby on rails 3 - nginx upload module -

i having trouble getting nginx upload module working rails application.

my route

     match '/images/fast_upload' => 'images#create', :via => :post 

image model

   attr_accessor :tmp_upload_dir    after_create  :clean_tmp_upload_dir      # handle new param     def fast_asset=(file)       if file && file.respond_to?('[]')       self.tmp_upload_dir = "#{file['filepath']}_1"       tmp_file_path = "#{self.tmp_upload_dir}/#{file['original_name']}"       fileutils.mkdir_p(self.tmp_upload_dir)       fileutils.mv(file['filepath'], tmp_file_path)       self.asset = file.new(tmp_file_path)       end    end       private  # clean tmp directory used in handling new param   def clean_tmp_upload_dir    fileutils.rm_r(tmp_upload_dir) if self.tmp_upload_dir && file.directory?  (self.tmp_upload_dir)   end         

nginx.conf

  upload_pass @fast_upload_endpoint;     upload_store /pathto/shared/uploads_tmp 1;     upload_store_access user:rw group:rw all:r;     upload_set_form_field upload[fast_asset][original_name] "$upload_file_name";   upload_set_form_field upload[fast_asset][content_type] "$upload_content_type";   upload_set_form_field upload[fast_asset][filepath] "$upload_tmp_path";    upload_pass_form_field "^image_id$|^authenticity_token$|^format$";   upload_cleanup 400 404 499 500-505;   }    location @fast_upload_endpoint {       passenger_enabled on;      rails_env production;   }    location / {    rails_env production;    passenger_enabled on;   } 

in controller create method

    def create      @image = current_user.images.build(params[:image])      if @image.save 

basically i'm not sure how create method use nginx upload. tried use @image = @resource.current_user.images.build(params[:image]) giving me undefined method error.

what should check parameters nginx passes when creating upload. have same logic do. create action i've got follows. bear me because i'm not able test parameters nginx passes now. think it's not "image" "upload"

@photo = @artist.photos.build(params[:upload]) 

is create method.