Jquery file upload in rails 4

Question

Hi everyone i am following the video tutorial for Jquery File Upload at http://railscasts.com/episodes/381-jquery-file-upload and am stuck. I after upload images my render partial does not refresh, it adds the new image and all other images under the image that was already attached. So if I add two images to a new item it shows the first image, then renders the partial again with the first image and the second image under the first so there are 3 photos in total.

Here is my create.js.erb

<% if @photo.new_record? %>
  alert("Failed to upload photo: <%= j @photo.errors.full_messages.join(', ').html_safe %>");
<% else %>
  $("#photos").append("<%=j render @photo %>");
<% end %>

Here is my render from my show page.

<div id="photos">
    <%= render 'photos/photo' %>
</div>

Here is my /photos/_photos.html.erb partial

<h2>Images</h2>
<div class="photo">
<% @rental.photos.each do |photo| %>
  <p>
    <strong>Photo:</strong>
    <%= image_tag photo.image_url.to_s %>
    </script>   
  </p>
 <% end %>
</div>

Here is my Photos Controller create

 def create
    @rental = Rental.find(params[:rental_id])
    @photo = @rental.photos.create(params[:photo].permit(:image))

    respond_to do |format|
      format.js
    end
  end

Here is my photos.js.jcoffee

jQuery ->
  $('#new_photo').fileupload(replaceFileInput: false,
    paramName: 'photo[image]')


    dataType: "script"
    add: (e, data) ->
      types = /(\.|\/)(gif|jpe?g|png)$/i
      file = data.files[0]
      if types.test(file.type) || types.test(file.name)
        data.context = $(tmpl("template-upload", file))
        $('#new_photo').append(data.context)
        data.submit()
      else
        alert("#{file.name} is not a gif, jpeg, or png image file")
    progress: (e, data) ->
      if data.context
        progress = parseInt(data.loaded / data.total * 100, 10)
        data.context.find('.bar').css('width', progress + '%')

Any help would be great, I'm stuck. Thanks!

---

Thank you so much Rich Peck his answer fully solved my problem. I had to change

<% if @photo.new_record? %>
  alert("Failed to upload photo: <%= j @photo.errors.full_messages.join(', ').html_safe %>");
<% else %>
  $("#photos").append("<%=j render @photo %>");
<% end %>

To

<% if @photo.new_record? %>
  alert("Failed to upload photo: <%= j @photo.errors.full_messages.join(', ').html_safe %>");
<% else %>
  $("#photos").html("<%=j render @photo %>");
<% end %>

Answer 1

def create
    @rental = Rental.find(params[:rental_id])
    @photo = @rental.photos.create(params[:photo].permit(:image))

    respond_to do |format|
        format.js
    end
end

That's my first look at it

---

The fix was actually to use $('#photos').html() to replace the container. The OP was originally using .append to just append content to the container, which didn't work very well at all