Source code for superdjango.db.expiration.managers

# Imports

from django.db import models
from django.utils.timezone import now

Q = models.Q

# Exports

__all__ = (
    "ExpirationManager",
    "ExpirationQuerySet",
    "ExpiredManager",
    "UnExpiredManager",
)

# QuerySets


class ExpirationQuerySet(models.QuerySet):
    """Works in conjunction with ``ExpirationModel`` to help filter out records
    that have expired.
    """

    def expired(self):
        """Filter for records that have expired."""
        query1 = Q(has_expired=True)
        query2 = Q(expiration_dt_lt=now())
        return self.filter(query1 | query2)

    def unexpired(self):
        """Filter for records that have not expired."""
        query1 = Q(has_expired=True)
        query2 = Q(expiration_dt__gt=now())
        return self.filter(~query1 | query2)


# Managers


class ExpirationManager(models.Manager):
    """Works in conjunction with ``ExpirationModel`` to filter by expiration.

    """

    def expired(self):
        """Get records that have expired.

        :rtype: QuerySet

        """
        return self.get_queryset().expired()

    def expiry(self):
        """Update all expired records.

        .. warning::
            This updates the database.

        """
        current_dt = now()

        criteria = {
            'expiration_dt__gt': current_dt,
            'has_expired': False,
        }
        qs = self.get_queryset().filter(**criteria)
        qs.update(has_expired=True)

    # noinspection PyMethodMayBeStatic
    def get_queryset(self):
        """Provide custom queryset."""
        return ExpirationQuerySet()

    def unexpired(self):
        """Get records that have not yet expired."""
        return self.get_queryset().unexpired()


class ExpiredManager(models.Manager):
    """Work only with expired records."""

    # noinspection PyMethodMayBeStatic
    def get_queryset(self):
        return ExpirationQuerySet().expired()


class UnExpiredManager(models.Manager):
    """Work only with unexpired records."""

    # noinspection PyMethodMayBeStatic
    def get_queryset(self):
        return ExpirationQuerySet().unexpired()