One To One field that does not rise an Exception

advanced_one_to_one_field.py

"""
One To One field that does not rise an Exception

In your models you now can write:

    class Profile(models.Model):
        user = AdvancedOneToOneField(User, related_name="profile")


And using in code like this:

    >>> test = User.objects.create(username="test")
    >>> test.profile
    <Profile object>

No more exceptions when using OneToOneField
"""
from django.db.models.fields.related import OneToOneField, SingleRelatedObjectDescriptor


class AdvancedSingleRelatedObjectDescriptor(SingleRelatedObjectDescriptor):
    """
    This Reated object descriptor returns empty object of related model
    if it does not exists, instead of rising an exception
    """
    
    def __get__(self, instance, instance_type=None):
        try:
            return super(AdvancedSingleRelatedObjectDescriptor, self).__get__(instance, instance_type)
        except self.related.model.DoesNotExist:
            kwargs = {self.related.field.name: instance}
            return self.related.model(**kwargs)

class AdvancedOneToOneField(OneToOneField):
    
    def contribute_to_related_class(self, cls, related):
        setattr(cls, related.get_accessor_name(),
                AdvancedSingleRelatedObjectDescriptor(related))