Source code for oioioi.participants.fields

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


def delete_related_participants_handler(sender, instance, **kwargs):
    try:
        instance.participant.delete()
    except ObjectDoesNotExist:
        # already deleted - nothing to do
        pass


class OneToOneBothHandsCascadingParticipantField(models.OneToOneField):
    def contribute_to_class(self, cls, name):
        super(OneToOneBothHandsCascadingParticipantField, self).contribute_to_class(
            cls, name
        )
        post_delete.connect(delete_related_participants_handler, sender=cls)