Django snippets

""" XPaginate FILE """

from math import *
from django import template
from django.template import Library, Node

register = template.Library()

"""
    Django Pagination Template Tag
    Allows for complete customization on pagination display
    Renders pages a template context with the following vars avaliable
    
    total_items:        List of total pagination items
    current:            Current Page pagination is on
    per_page:           How many items per page
    has_previous:       Has links to display that go to previous pages
    has_next:           Has links to display that go fowards pages
    foward_pages:       Dictionary contaning forward page numbers
    previous_links:     Dictionary containing previous page numbers
    has_jump_previous:  Has links that "jump" backwords through previous page numbers
    has_jump_foward:    Has page numbers that "jump" through foward page numbers
    foward_page_jump:   Dictionary containg list of forward jumping page numbers
    foward_page_jump:   Dictionary containg list of previous jumping page numbers
    show_last:          Boolean that smartly determains the current page location to display a link to the last page
    show_last:          Boolean that smartly determains the current page location to display a link to the first page
"""

class XPaginate:
    def __init__(self, uri, total_items, current, per_page, show, jump, range):
        self.total_items = int(total_items)
        self.current = int(current)
        self.per_page = int(per_page)
        self.show = int(show)
        self.jump = jump
        self.range = int(range)
        self.jump_calc = 2
        self.uri = uri
        
        if self.current is 0:
            self.current = 1
        
        # Total number of pages
        self.total_pages = int(ceil(float(total_items) / float(per_page)))
        
        if self.current is not 1:
            self.has_previous = True
        else:
            self.has_previous = False
            
        if self.current < self.total_pages:
            self.has_next = True
        else:
            self.has_next = False
        
        # Get the first foward set of page links if avaliable
        self.foward_pages = []
        if self.has_next:
            a = self.current
            self.foward = int(self.current + 1)
            total = 0
            while total is not self.show:
                a = a + 1
                total = total + 1
                if a <= self.total_pages:
                    if total is self.show:
                        last_foward = a
                    self.foward_pages.append(a)
            if last_foward is self.total_pages or (last_foward + self.show) > self.total_pages:
                self.show_last = False
            else:
                self.show_last = True
            #print self.foward_pages, '\n'
        
        # GET the set of previous pages
        self.previous_pages = []
        if self.has_previous:
            self.previous = int(self.current - 1)
            a = int((self.current - 1) - self.show)
            total = 0
            while total is not self.show:
                a = a + 1
                total = total + 1
                if a <= self.total_pages and a is not 0:
                    if total is self.show:
                        last_previous = int(a)
                    self.previous_pages.append(a)
            
            #print self.previous_pages, '\n'
                    
        # Calculate if we have the ability to jump foward pages
        if self.jump and (self.current - ceil(self.range * self.jump_calc)) >= 2:
            self.has_jump_previous = True
        else:
            self.has_jump_previous = False
            
        if self.jump and (self.current + ceil(self.range * self.jump_calc)) < self.total_pages:
            self.has_jump_foward = True
        else:
            self.has_jump_foward = False
        
        ## Calc Jump pages foward
        
        if self.has_jump_foward:
            a = last_foward
            total = 0
            self.foward_page_jump = []
            while total is not self.range:
                total = total + 1
                a = int(float(ceil(a * self.jump_calc)))
                if a <= self.total_pages:
                    self.foward_page_jump.append(a)
            
        if self.has_jump_previous:
            a = int(last_previous)
            total = 0
            self.previous_page_jump = []
            while total is not self.range:
                total = total + 1
                a = int(ceil(a / float(self.jump_calc)))
                if a <= self.total_pages and a >= 2:
                    self.previous_page_jump.insert(0, a)
        
class RenderXPage(Node):
    def __init__(self, uri, total_items, current, per_page, show, jump, range):
        self.total_items = template.Variable(total_items)
        self.current = template.Variable(current)
        self.uri = template.Variable(uri)
        if not per_page:
            self.per_page = 10
        else:
            self.per_page = per_page
        if not show:
            self.show = 3
        else:
            self.show = show
        if not jump:
            self.jump = True
        else:
            self.jump = jump
        if not range:
            self.range = 3
        else:
            self.range = range

    def render(self, context):
        
        try:
            context['xpaginate'] = XPaginate(self.uri.resolve(context), self.total_items.resolve(context), self.current.resolve(context), self.per_page, self.show, self.jump, self.range)
        except:
            pass
        
        return ''

def xpaginator(parser, token):
    tokens = token.split_contents()
    return RenderXPage(tokens[1], tokens[2], tokens[3], tokens[4], tokens[5], tokens[6], tokens[7])

register.tag('xpaginator', xpaginator)

""" XPaginate Tempalte File """
<div class="pagination">
{% if xpaginate.has_previous %}
<a href="{{ xpaginate.uri }}{{ xpaginate.previous }}"><< Previous</a>
    {% if xpaginate.has_jump_previous %}
        {% for a in xpaginate.previous_page_jump %}
            <a href="{{ xpaginate.uri }}{{ a }}">{{ a }}</a> ... 
        {% endfor %}
    {% endif %}
    {% for a in xpaginate.previous_pages %}
        <a href="{{ xpaginate.uri }}{{ a }}">{{ a }}</a>
    {% endfor %}
{% endif %}

<span class="current">[ {{ xpaginate.current }} ]</span>

{% if xpaginate.has_next %}
    {% for a in xpaginate.foward_pages %}
        <a href="{{ xpaginate.uri }}{{ a }}">{{ a }}</a>
    {% endfor %}
    {% if xpaginate.show_last %}
        ... <a href="{{ xpaginate.uri }}{{ xpaginate.total_pages }}">{{ xpaginate.total_pages }}</a>
    {% endif %}
    <a href="{{ xpaginate.uri }}{{ xpaginate.foward }}">Next >></a>
{% endif %}
</div>


""" DIRECTORY STRUCTURE """
|-- xpaginate
  |-- templatetags
    |-- xpaginate.py
|-- path/to/view/templates
  |-- xpaginate.html

""" USAGE EXAMPLE """

NOTE:
You must add **xpaginate** to you INSTALLED_APPS list

[ view.py ]
from urlgen.urlgen import urlGen

cards = Card.objects.all().order_by('name')

items = cards.count()
paginator = Paginator(cards, 16) # Show 25 contacts per page

# Make sure page request is an int. If not, deliver first page.
try:
    page = int(request.GET.get('page', '1'))
except ValueError:
    page = 1

# If page request (9999) is out of range, deliver last page of results.
try:
    cards = paginator.page(page)
except (EmptyPage, InvalidPage):
    cards = paginator.page(paginator.num_pages)
    
"""
USES URI Generator Snippet
http://www.djangosnippets.org/snippets/1734/
"""

url = urlGen()

pageURI = url.generate('page', request.GET)

cards = cards.object_list

return render_to_response('template.html', {'cards': cards,
                                            'total_item': items,
                                            'pageURI': pageURI,
                                            'current': page         
                                            }, context_instance=RequestContext(request))

[ template.html ]
{% for card in cards %}
    <li>
        <span>{{ card.name }}</span>
    </li>
{% endfor %}
{% load xpaginator %}
{% xpaginator pageURI total_item current 16 1 True 1 %}
{% include "xpaginate.html" %}

Template Tag accepts the following parameters
uri: URI to use for link, EX ?page=
total_items: total number of items
current: current page that user is on
per_page: items displayed per page
show: OPTIONAL: how many links to display on left and right of current page
jump: OPTIONAL: create a list of links that jump through pages increasing by 1.2* the current
range: Number of jumped links to calculate and display on for forward and reverse