pbp_com/apps/catalog/managers.py

from django.core.exceptions import ObjectDoesNotExist
from django.db import models

class ItemManager(models.Manager):

    def active(self):
        return self.filter(is_active=True, deleted=False)

    def featured_items(self):
        return self.active().filter(featured=True)


class SubscriptionManager(ItemManager):

    def __init__(self, *args, **kwargs):
        super(SubscriptionManager, self).__init__(*args, **kwargs)

    def valid_options(self, shipping_type=None, shipping_method=None):
        """
        :param type: INSTATE, OUTSTATE, FOREIGN
        :returns: Only valid subscriptions related to the specific first class
            option
        """
        q = self.active()
        if shipping_type:
            q.filter(shipping_type=shipping_type)
        if shipping_method:
            q = q.filter(shipping_method=shipping_method)
        return q.order_by('title', 'duration')

    def _valid_value_list(self, value, shipping_type=None,
                          shipping_method=None):
        return self.valid_options(
            shipping_type, shipping_method).distinct().values_list(value,
                                                                   flat=True)

    def titles_value_list(self, shipping_type, shipping_method=None):
        return self._valid_value_list(
            'title', shipping_type, shipping_method=shipping_method)

    def durations_value_list(self, shipping_type, shipping_method=None):
        return self._valid_value_list(
            'duration', shipping_type, shipping_method=shipping_method)

    def shipping_method_value_list(self, shipping_type):
        return self._valid_value_list('shipping_method', shipping_type)

    def title_images(self):
        return self.active().exclude(image__isnull=True).exclude(
            image='').values('title', 'image')

    def find_price(self, shipping_type, title, duration, shipping_method):
        try:
            price = self.get(
                shipping_type=shipping_type, title=title, duration=duration,
                shipping_method=shipping_method).price
        except ObjectDoesNotExist:
            price = None
        return price


class ZipCodeManager(models.Manager):

    def active(self):
        return self.filter(is_active=True, deleted=False)


class PersonManager(models.Manager):

    def get_queryset(self):
        return super(PersonManager, self).get_query_set().active()

    def active(self):
        return self.filter(is_active=True, deleted=False)