error message not rendering in containing div

I have a form that looks like this -

<%= form_for @photo,:html=>{:multipart=>true} do |f| -%>
<div> 
       <%= f.file_field :photo %>
       <%= f.submit "Upload", :disable_with => 'Uploading...' %>
</div>
    <%= @photo.errors[:photo].each do |attr,msg| %>
         <span class="form-error"><%= msg %></span>
    <% end %>   
<开发者_C百科;% end -%>

My model has the following line

  validates_presence_of :photo, :message => "Choose a file to upload"

For some reason the error message is rendering outside of containing span. The rendered HTML looks like this -

<form ..some attributes..><some hidden divs and inputs />
  <div class="field_with_errors"><input type="file" name="photo[photo]" id="photo_photo"></div>
  <input type="submit" value="Upload" name="commit" id="photo_submit" data-disable-with="Uploading...">
  <span class="form-error"></span>
  Choose a file to upload
</form>

I'm very new to rails, but this seems odd to me.

Why is my message outside of it's container?

Thanks.

---

Shouldn't this NOT have an equal sign (you like my double negative there)?

<%= @photo.errors[:photo].each do |attr,msg| %>
 / \
  |
  |

In other words, it should be:

<% @photo.errors[:photo].each do |attr,msg| %>

I've made this typo about a hundred times, and have finally got out of the habit of doing it. I'll bet that is part of the issue.

Your form_for needs and equal sign, because it outputs HTML into your view. The loop itself does not, because it is just a loop.