The Big Loop

gistfile1.html

<ul>
{% for collection in collections %}
  {% unless collection.products_count == 0 %}
  <li>
    {{ collection.title | link_to: collection.url }}
    {% if collection.all_tags.size > 0 %}
    <ul>
      {% for tag in collection.all_tags %}
      {% capture url %}{{ collection.url }}/{{ tag | handle }}{% endcapture %}
      <li>{{ tag | link_to: url }}</li>
      {% endfor %}
    </ul>
    {% endif %}
  </li>
  {% endunless %}
{% endfor %}
</ul>