LastOnlineMiddleware

import re
import logging
from django.conf import settings
from django.core.cache import cache
from userprofile.models import LastOnline
import datetime
from django.core.urlresolvers import reverse


class LastOnlineMiddleware(object):
    """Log the last time a user was online"""
    
    def process_request(self, request):
        
        if request.user.is_authenticated() and not request.path.startswith(reverse('admin:index')) and not request.path.startswith(settings.MEDIA_URL):  
            cache_created = cache.add('last_online_%s' % request.user.id, datetime.datetime.now(), settings.LAST_ONLINE_CACHE_EXPIRE_IN_SECONDS)
            
            if cache_created:
                last_online, created = LastOnline.objects.get_or_create(user=request.user)
                if not created:
                    last_online.save()