_upload_with_feedback.html.erb

<% content_for :head do %>
  <%= javascript_include_tag 'jquery.uploadify' %>

  <% javascript_tag do %>
    $(document).ready(function() {
      $("#file_uploader").fileUpload({
      	'uploader': '/flash/uploader.swf',
      	'script': '<%= url %>',
      	'scriptData': { 'format': 'json', 'authenticity_token': encodeURIComponent('<%= form_authenticity_token if protect_against_forgery? %>'), '<%= Rails.configuration.action_controller.session[:session_key]%>': '<%= u session.session_id %>' },
      	'fileDataName': $('#file_uploader input:file')[0].name, // Extract correct name of upload field from form field
      	//'scriptAccess': 'always', // Incomment this, if for some reason it doesn't work
      	'multi': <%= allow_multiple_files %>,
      	'auto': true,
      	'fileDesc': '<%= dialog_file_description %> (<%= allowed_extensions.collect { |ext| "*.#{ext}" }.join(';') %>)',
      	'fileExt': '<%= allowed_extensions.collect { |ext| "*.#{ext}" }.join(';') %>',
      	'sizeLimit': <%= max_size %>,
      	'simUploadLimit': 1,
      	'buttonImg': '/images/button-fixed.png',
      	'width': 120, 
      	'height': 24,
      	'cancelImg': '/images/cancel.png',
      	'onComplete': function(event, data) { $.getScript(location.href) }, // We assume that we can refresh the list by doing a js get on the current page
    		'displayData': 'speed'
      });
    });
  <% end %>
<% end %>

<div id="file_uploader">
  <p><%= f.file_field :uploaded_data %></p>
  <div class="submitbutton"><%= submit_tag "Upload" %></div>
</div>