Rails 3 file upload (manual)

form.html.haml

= form_for @photo, :html => { :multipart => true } do |f|
  .field
    = f.label :title
    = f.text_field :title
  
  - if !@photo.img_original.nil? and !@photo.img_original.empty?
    %img{:src => "/uploads/#{@photo.img_original}", :border => 1, :width => 50, :height => 50 }

  .field
    = f.label 'New file'
    = f.file_field 'file'

  .actions
    = f.submit 'Save'

photos_controller.rb

class PhotosController < ApplicationController  
  def create
    path = save_file(params[:photo], :file)
    @photo = Photo.new(params[:photo])
    @photo.img_original = path
    
    respond_to do |format|
      if @photo.save
        format.html { redirect_to(photo_path(@photo), :notice => 'Photo was successfully created.') }
        format.xml  { render :xml => @photo, :status => :created, :location => @photo }
      else
        format.html { render :action => "new" }
        format.xml  { render :xml => @photo.errors, :status => :unprocessable_entity }
      end
    end
  end

  def save_file(formdata, name)
    ufile = formdata[name]
    if ufile
      path = Rails.root.join('public', 'uploads', ufile.original_filename)
      File.open(path, 'wb') do |file|
        file.write(ufile.read)
      end

      formdata.delete name

      #return path as string
      path.relative_path_from(Rails.root.join('public', 'uploads')).to_s
    else
      nil  
    end
  end
end