gistfile1.txt

# _form.html.erb
<%= f.fields_for :file_attachments do |builder| %>
  <%= render 'file_attachment_fields', :f => builder %>
<% end %>

# _file_attachment_fields.html.erb
<div class="clearfix fields">
  <label>Name:</label>
  <div class="input">
    <%= f.text_field :name %>
    <%= f.file_field :attachment %>
    <%= f.hidden_field :_destroy %>
    <%= link_to_function "Remove", "remove_fields(this)" %>
  </div>
</div>

# So what I'd like to do is make the partial something like:

<div class="clearfix fields">
  <label>Name:</label>
  <div class="input">
    <%= f.text_field :name %>
    <% if @file_attachment.new? %>
      <%= f.file_field :attachment %>
    <% else %>
      <a href="<%= @file_attachment.attachment.url %>"><%= @file_attachment.attachment_file_name %></a>
    <% end %>
    <%= f.hidden_field :_destroy %>
    <%= link_to_function "Remove", "remove_fields(this)" %>
  </div>
</div>

# But using fields_for and passing in a collection 
# I'm unsure how I can access the current object 
# (ala @file_attachment) in the iteration.

and f.object doesn't work?

I did not know about f.object. Seems to work. Thanks!