Question

I have 10 form fields and I want to append a number next to each field, going sequentially from 1 to 10. The problem is that the code is already in a loop. It’s inside a partial, and the partial is passed a collection.

<%= fields_for "list", f do |f| %>
    <!-- I want 1, 2, etc to appear here depending on the iteration. -->
    <%= f.label :name %>

I tried using <%= i += 1 %> but it does not work since i is not defined. If I define i, it will keep getting reset to the same number, so it makes no difference. Any ideas?

Answer 1

Rails automatically defines a local variable called partialname_counter where, obviously, “partialname” is the name of your partial. So if your partial is called e.g. _list_item.html.erb you could write it like this:

<%= fields_for "list", f do |f| %>
  <%= list_item_counter + 1 %>
  <%= f.label :name %>
<% end %>

(The + 1, of course, is there because the counter starts at 0.)

Another option would be to just let the browser do the numbering for you using an ordered list:

In the view:

<ol>
  <%= render :list_item, :collection => @some_items %>
</ol>

…and in the partial:

<%= fields_for "list", f do |f| %>
  <li>
    <%= f.label :name %>
  </li>
<% end %>

This option is probably more semantic, and lists are easy to style in CSS.