<div class="file-upload" data-<%= model_name %>-id="<%= model_instance.id %>">
  <%= form_for model_instance, :url    => update_route,
                               :remote => true,
                               :method => "put",
                               :html   => { :class     => "file-upload",
                                            :id        => "#{model_name}-#{attribute_name}",
                                            :multipart => true } do |f| %>
    <div class="file-info row-fluid">
      <div class="existing-file-image span5">
        Current File

        <%= image_tag f.object.reload.send(attribute_name) %>
      </div>

      <div class="new-file-select span7">
        <label class="btn file-upload-label">
          Upload New File...
          <%= f.file_field attribute_name.to_sym %>
        </label>

        <div class="selected-file-preview"></div>
      </div>
    </div>
  <% end %>
</div>

<div class="file-upload" data-<%= model_name %>-id="<%= model_instance.id %>">
  <%= form_for model_instance, :url    => update_route,
                               :remote => true,
                               :method => "put",
                               :builder => ErrorMessagesFormBuilder,
                               :html   => { :class     => "file-upload",
                                            :id        => "#{model_name}-#{attribute_name}",
                                            :multipart => true } do |f| %>
    <div class="file-info row-fluid">
      <%= f.error_messages %>

      <div class="existing-file-image span5">
        Current File

        <%= image_tag f.object.reload.send(attribute_name) %>
      </div>

      <div class="new-file-select span7">
        <label class="btn file-upload-label">
          Upload New File...
          <%= f.file_field attribute_name.to_sym %>
        </label>

        <div class="selected-file-preview"></div>
      </div>
    </div>
  <% end %>
</div>

Update File Upload Form Partial for Error Messages
Update File Upload Form Partial for Error Messages

Update the partial to utilize and render error messages for an invalid
file format (or any other errors corresponding to the object).
