Rails回形针图像URL上传不起作用

class Konkurrancer < ActiveRecord::Base

    has_attached_file :photo,
                      :url  => \"/public/images/billeder/photo/:id/:basename.:extension\",
                      :path => \":rails_root/public/images/billeder/photo/:id/:basename.:extension\"

    has_attached_file :photo2,
                      :url  => \"/public/images/billeder/photo2/:id/:basename.:extension\",
                      :path => \":rails_root/public/images/billeder/photo2/:id/:basename.:extension\"

      attr_accessor :photo_url, :photo_url2

      def photo_url=(url) 
        return if url.blank?
        self.photo = RemoteUpload.new(url)
      end

      def photo_url2=(url) 
        return if url.blank?
        self.photo2 = RemoteUpload.new(url)
      end
end

    def new
        @konkurrancer = Konkurrancer.new
        if !params[:konkurrancer].nil? && !params[:konkurrancer][:photo_url].blank?
        # user entered a photo url, use the url
        @konkurrancer.photo_remote_url = params[:konkurrancer][:photo_remote_url]
        elsif !params[:konkurrancer].nil? && !params[:konkurrancer][:photo]
         # use file upload  
        @konkurrancer.photo = params[:konkurrancer][:photo]
    end

    if !params[:konkurrancer].nil? && !params[:konkurrancer][:photo_url_2].blank?
      # user entered a photo url, use the url
      @konkurrancer.photo_remote_url = params[:konkurrancer][:photo_remote_url_2]
    elsif !params[:konkurrancer].nil? && !params[:konkurrancer][:photo]
      # use file upload
      @konkurrancer.photo2 = params[:konkurrancer][:photo2]
    end

        respond_to do |format|
          format.html # new.html.erb
          format.xml  { render :xml => @konkurrancer }
        end
      end

  # POST /konkurrancers
      # POST /konkurrancers.xml
      def create
        @konkurrancer = Konkurrancer.new(params[:konkurrancer])

        respond_to do |format|
          if @konkurrancer.save
            format.html { redirect_to(:admin_konkurrancers, :notice => \'Konkurrancer was successfully created.\') }
            format.xml  { render :xml => :admin_konkurrancers, :status => :created, :location => @konkurrancer }
          else
            format.html { render :action => \"new\" }
            format.xml  { render :xml => @konkurrancer.errors, :status => :unprocessable_entity }
          end
        end
      end

require \'open-uri\'

# Make it always write to tempfiles, never StringIO
OpenURI::Buffer.module_eval {
  remove_const :StringMax
  const_set :StringMax, 0
}

class RemoteUpload 

  attr_reader :original_filename, :attachment_data

  def initialize(url) 
    # read remote data
    @attachment_data    = open(url)

    # determine filename
    path = self.attachment_data.base_uri.path

    # we need this attribute for compatibility to paperclip etc.
    @original_filename = File.basename(path).downcase
  end

  # redirect method calls to uploaded file (like size etc.)
  def method_missing(symbol, *args)
    if self.attachment_data.respond_to? symbol
      self.attachment_data.send symbol, *args
    else
      super
    end
  end

end

<%= simple_form_for [:admin, @konkurrancer], :html => { :multipart => true } do |f| %>
    <%= f.input :name, :label => \'Titel\', :style => \'width:500;\' %>
    <%= f.label :upload_125x125 %>
    <%= f.file_field :photo, :label => \'125x125\', :style => \'width:250;\' %>
    <%= f.input :photo_url, :label => \'URL 125x125\', :style => \'width:250;\' %>
    <%= f.label :upload_460x60 %>
    <%= f.file_field :photo2, :label => \'460x58\', :style => \'width:250;\' %>
    <%= f.input :photo_url2, :label => \'URL 460x58\', :style => \'width:250;\' %>
    <%= f.button :submit, :value => \'Create konkurrence\' %>
<% end %>