Splitting A Hash Into Multiple Unordered Lists

Question

I have been searching in vain to accomplish the following in a more clean manner.

I have a hash of strings which I am calling from my controller:

@categories = Category.find

and I am trying to display the results in three separate unordered lists (ul).

The following is an ugly version of what I am trying to accomplish:

<div class="span-7">
    <ul>
    <% @categories.first(4).each do |category| %>

        <li><%= category.name %></li>

    <% end %>
    </ul>       
</div>

<div class="span-7">
    <ul>
    <% @categories[5..8].each do |category| %>

        <li><%= category.name %></li>

    <% end %>
    </ul>       
</div>

<div class="span-8 last">
    <ul>
    <% @categories[9..12].each do |category| %>

        <li><%= category.name %></li>

    <% end %>
    </ul>       
</div>

(Note: I am using BlueprintCSS, thus the excess of "span-x")

I think there is a cleaner way to do this using grouping (http://rails.rubyonrails.org/classes/ActiveSupport/CoreExtensions/Array/Grouping.html) but I can't figure out how to tie all of this together.

I'd really appreciate it if someone could point me in the right direction. Thank you.

(I am using Rails 3.0.11)

Answer 1

You're on the right track. This should do what you want.

<% category_count = 0 %>
<% @categories.in_groups_of(4) do |group| %>
  <% category_count += group.size %>
  <div class="<%= category_count == @categories.size ? "span-8 last" : "span-7" %>">
    <ul>
    <% group.each do |category| %>
      <% if category %>
      <li><%= category.name %></li>
      <% end %>
    <% end %>
    </ul>       
  </div>
<% end %>