from django import template

register = template.Library()

@register.inclusion_tag('pagination.html')
def show_pagination(pagination, request, get_param_name):
    """
    pagination : ObjectPaginator from the view
    request : needed to keep get variables
    get_param_name : tell which parameters to use in links/request.GET

    All variables are set here for the template rendering.
    You will maybe not needs all for your own template.

    """
    if(request.GET.has_key(get_param_name)):
        current_page = int(request.GET[get_param_name])
    else:
        current_page = 0
    has_previous = pagination.has_previous_page(current_page)
    has_previous_previous = pagination.has_previous_page(current_page-1)
    has_next = pagination.has_next_page(current_page)
    has_next_next = pagination.has_next_page(current_page+1)
    need_pagination = has_previous or has_next
    
    has_start_page = current_page > 2
    has_end_page = (pagination.pages - current_page) > 3
    
    has_start_hellip = current_page > 3
    has_end_hellip = (pagination.pages - current_page) > 4
    
    total_pages = pagination.pages
    
    get_params = ''
    for key, value in request.GET.iteritems():
        if not key == get_param_name:
            if get_params == '':
                get_params = '?'+key+'='+str(value[0])
            else:
                get_params += '&'+key+'='+str(value[0])
    if get_params == '':
        get_params = '?'+get_param_name+'='
    else:
        get_params += '&'+get_param_name+'='
    return locals()

'''An example for pagination.html file :'''

{% load math_filters %}
{% if need_pagination %}
{% if has_start_page %}<a href="{{ get_params }}0">1</a>{% endif %}
{% if has_start_hellip %}&hellip;{% endif %}
{% if has_previous_previous %}<a href="{{ get_params }}{{ current_page|sub:2 }}">{{ current_page|sub:1 }}</a>{% endif %}
{% if has_previous %}<a href="{{ get_params }}{{ current_page|sub:1 }}">{{ current_page }}</a> {% endif %}
<strong>[{{ current_page|add:1 }}]</strong>
{% if has_next %}<a href="{{ get_params }}{{ current_page|add:1 }}"> {{ current_page|add:2 }}</a>{% endif %}
{% if has_next_next %}<a href="{{ get_params }}{{ current_page|add:2 }}"> {{ current_page|add:3 }}</a>{% endif %}
{% if has_end_hellip %}&hellip;{% endif %}
{% if has_end_page %}<a href="{{ get_params }}{{ total_pages|sub:1 }}">{{ total_pages }}</a>{% endif %}
{% endif %}

'''Note that this template use this stupid sub filter :'''

from django import template

register = template.Library()

def sub(value, arg=None):
    return value-arg

register.filter('sub', sub)

'''An example for the view :'''

from django.core.paginator import ObjectPaginator, InvalidPage
if request.GET.has_key('page_members'):
    page_users = int(request.GET['page_members'])
else:
    page_users = 0
users = User.objects.order_by('-last_login')
users_paginator = ObjectPaginator(users, 5)
users = users_paginator.get_page(page_users)

'''Code example of the template tag :'''

{% load pagination_filters %}
{% show_pagination users_paginator request "page_members" %}