digg-style pagination with Django templates, e.g. "... 3 4 5 *6* 7 8 9 ..." and Twitter bootstrap

arithmetic.py

from django import template

"""It's sometimes really handy to be able to do basic arithmetic in
Django templates.

"""


register = template.Library()


@register.filter
def subtract(value, arg):
    return value - arg


@register.filter
def add(value, arg):
    return value + arg

template.html

<div class="pagination">
    <ul>
        <li {% if not table.page.has_previous %}class="disabled"{% endif %}>
            <a href="{% querystring table.prefixed_page_field=table.page.previous_page_number %}">&laquo;</a>
        </li>

        {% with active_page=table.page.number %}
        
        {% for page_number in table.paginator.page_range %}

            {# if we're beyond the first five pages, just show "..." until three pages before the current page #}
            {# e.g. on page 12 show: "... 9 10 11 12" #}
            {% if active_page > 5 and page_number < active_page|subtract:4 %}
                {# nothing to show #}
            {% elif active_page > 5 and page_number == active_page|subtract:4 %}
                {# show '...' #}
                <li class="disabled">
                    <a href="#">...</a>
                </li>

            {# if we're before the last five pages, just show "..." for pages more than three after the current page #}
            {# e.g. on page 1 of 10 show: "1 2 3 4 ..." #}
            {% elif active_page < table.paginator.num_pages|subtract:5 and page_number > active_page|add:4 %}
                {# nothing to show #}
            {% elif active_page < table.paginator.num_pages|subtract:5 and page_number == active_page|add:4 %}
                {# show '...' #}
                <li class="disabled">
                    <a href="#">...</a>
                </li>

            {% else %}
                {# show the page number as normal #}
                <li {% if page_number == active_page %}class="active"{% endif %} foo="3">
                    <a href="{% querystring table.prefixed_page_field=page_number %}">{{ page_number }}</a>
                </li>
            {% endif %}
             
        {% endfor %}

        {% endwith %}

        <li {% if not table.page.has_next %}class="disabled"{% endif %}>
            <a href="{% querystring table.prefixed_page_field=table.page.next_page_number %}">&raquo;</a>
        </li>
    </ul>
</div>