{% set absolute_url = absolute_url+ gallery.link+"/" -%}
<item>
    <title>{{ gallery.title }}</title>
    <link>{{ absolute_url }}</link>
    <guid>{{ gallery.link }}</guid>
    {% if gallery.sub_title -%}
    <description>{{ gallery.sub_title }}</description>
    {% endif -%}
    <pubDate>{{ gallery.date }}</pubDate>
</item>
{% for sub_gallery in gallery.sub_gallery %}
    {% with gallery=sub_gallery %}
    {% include "item.html" %}
    {% endwith %}
{% endfor %}