Extends Django CMS sub menu template tag and adds pagination

extended_menu_tags.py

from django import template
from classytags.arguments import IntegerArgument, Argument, StringArgument
from classytags.core import Options
from menus.templatetags.menu_tags import ShowSubMenu
from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger

register = template.Library()


class ShowPaginatedSubMenu(ShowSubMenu):
    """
    show a paginated sub menu of the current nav-node.
    - levels: how many levels deep
    - root_level: the level to start the menu at
    - nephews: the level of descendants of siblings (nephews) to show
    - page_size: The Paginator page size
    - template: template used to render the navigation
    """
    name = 'show_paginated_sub_menu'
    template = 'menu/dummy.html'

    options = Options(
        IntegerArgument('levels', default=100, required=False),
        Argument('root_level', default=None, required=False),
        IntegerArgument('nephews', default=100, required=False),
        IntegerArgument('page_size', default=4, required=False),
        Argument('template', default='menu/paginated_sub_menu.html', required=False),
    )

    def get_context(self, context, levels, root_level, nephews, page_size, template):
        context = super(ShowPaginatedSubMenu, self).get_context(context, levels, root_level, nephews, template)

        try:
            # If there's an exception (500), default context_processors may not be called.
            request = context['request']
        except KeyError:
            return {'template': 'menu/empty.html'}

        print dir(context['current_page'])
        children = context['children']
        paginator = Paginator(children, page_size)
        page = request.GET.get('page')

        try:
            paginated_children = paginator.page(page)
        except PageNotAnInteger:
            # If page is not an integer, deliver first page.
            paginated_children = paginator.page(1)
        except EmptyPage:
            # If page is out of range (e.g. 9999), deliver last page of results.
            paginated_children = paginator.page(paginator.num_pages)

        context['children'] = paginated_children
        return context


register.tag(ShowPaginatedSubMenu)