Source code for superdjango.db.primary.managers

# Imports

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

# Exports

__all__ = (
    "PrimaryManager",
)


# Managers


class PrimaryManager(models.Manager):
    """Supports the ``PrimaryModel``.

    .. code-block:: py

        from superdjango.db.primary.managers import PrimaryManager
        from superdjango.db.primary.models import PrimaryModel

        class EmergencyContact(PrimaryModel):
            employee = models.ForeignKey(Employee, related_name="emergency_contacts")
            # ...

        employee = Employee.objects.get(pk=1)
        contact = employee.emergency_contacts.primary()

    """

    def primary(self):
        """Get the primary record."""
        try:
            return self.get_queryset().get(is_primary=True)
        except ObjectDoesNotExist:
            return None