For my current project perva.de, I’ve been playing with Django’s core pagination class django.core.paginator.ObjectPaginator. I wrote this wrapper that adds some nice functions that are helpful for rendering. Drop me some comments if you have ideas on how it could be better or “hey ro60 your an idiot you should do this instead” is always welcome too.

Please to enjoy… yes?!

"""
    This object inherits from the Django core ObjectPaginator class and
    provides some aditional helpful calculations for rendering pagination links
"""
from django.core.paginator import ObjectPaginator, InvalidPage
class NFPaginator(ObjectPaginator):

    def _set_current_page(self, current_page):
        try:
            self._current_page = int(current_page)
        except:
            self._current_page = 0

    def _get_current_page(self):
        return self._current_page

    def _get_display_page(self):
        if self._current_page == 0:
            return 1
        else:
            return self._current_page

    def _get_next_page(self):
        try:
            if ObjectPaginator.has_next_page(self,self._current_page):
                return self._current_page + 1
            else:
                return -1
        except:
            NFLogger.message(sys.exc_info(),"exception")

    def _get_previous_page(self):
        try:
            if ObjectPaginator.has_previous_page(self,self._current_page):
                return self._current_page - 1
            else:
                return -1
        except:
            NFLogger.message(sys.exc_info(),"exception")

    def get_page(self, page_number):
        #if the page is invalid then we get the first page
        try:
            return ObjectPaginator.get_page(self,page_number)
        except InvalidPage:
            self._current_page = 0
            return ObjectPaginator.get_page(self,self._current_pager)

    def render_next(self):
        return ObjectPaginator.has_next_page(self,self._current_page)

    def render_previous(self):
        return ObjectPaginator.has_previous_page(self,self._current_page)

    display_page = property(_get_display_page)
    current_page = property(_get_current_page,_set_current_page)
    next_page = property(_get_next_page)
    previous_page = property(_get_previous_page)

Then in your view

from pervade.netflippers import NFPaginator
def index(request):
    if 'page' in request.GET:
        page = request.GET['page']
    else:
        page = 0

    paginator = NFPaginator(Bookmark.objects.all().order_by(’-created_at’), 2,0)

    paginator.current_page = page
    latest_bookmark_list = paginator.get_page(page)
    return render_to_response(’bookmarks/index.html’, {’latest_bookmark_list’: latest_bookmark_list, ‘paginator’:paginator}, context_instance=RequestContext(request))

This all makes rendering a template allot simpler. Here is a link to a template partial that you can use.

P.S. There are calls to my logger class in here as well. Feel free to rip them out if you wish OR better yet include the logger as well.

Thx to Timmah for the comments. I’ve edited the get_page method to fix the blind page display issue.

This entry was posted on Thursday, December 27th, 2007 at 1:04 pm and is filed under development, django, python, tutorials. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.