Python django.db.models.OneToOneField() Examples

def convert(self, dj_field):
        result = []
        if isinstance(dj_field, (ForeignKey, OneToOneField)):
            result.append(dj_field.column)
            convert_from = dj_field.target_field
        else:
            result.append(dj_field.name)
            convert_from = dj_field
        internal_type = convert_from.get_internal_type()
        convert_to = self._types.get(internal_type)
        if convert_to is not None:
            result.append(self._convert_type(convert_from, convert_to))
        else:
            logger.info(
                'Not found corresponding '
                'SQLAlchemy type for "%s"(%r)',
                internal_type,
                dj_field
            )
        return sa.column(*result) 

def test_lookup_allowed_onetoone(self):
        class Department(models.Model):
            code = models.CharField(max_length=4, unique=True)

        class Employee(models.Model):
            department = models.ForeignKey(Department, models.CASCADE, to_field="code")

        class EmployeeProfile(models.Model):
            employee = models.OneToOneField(Employee, models.CASCADE)

        class EmployeeInfo(models.Model):
            employee = models.OneToOneField(Employee, models.CASCADE)
            description = models.CharField(max_length=100)

        class EmployeeProfileAdmin(ModelAdmin):
            list_filter = [
                'employee__employeeinfo__description',
                'employee__department__code',
            ]

        ma = EmployeeProfileAdmin(EmployeeProfile, self.site)
        # Reverse OneToOneField
        self.assertIs(ma.lookup_allowed('employee__employeeinfo__description', 'test_value'), True)
        # OneToOneField and ForeignKey
        self.assertIs(ma.lookup_allowed('employee__department__code', 'test_value'), True) 

def test_parent_child_one_to_one_link(self):
        # Since the parent and child are linked by an automatically created
        # OneToOneField, you can get from the parent to the child by using the
        # child's name.
        self.assertEqual(
            Place.objects.get(name="Demon Dogs").restaurant,
            Restaurant.objects.get(name="Demon Dogs")
        )
        self.assertEqual(
            Place.objects.get(name="Ristorante Miron").restaurant.italianrestaurant,
            ItalianRestaurant.objects.get(name="Ristorante Miron")
        )
        self.assertEqual(
            Restaurant.objects.get(name="Ristorante Miron").italianrestaurant,
            ItalianRestaurant.objects.get(name="Ristorante Miron")
        ) 

def test_lookup_allowed_onetoone(self):
        class Department(models.Model):
            code = models.CharField(max_length=4, unique=True)

        class Employee(models.Model):
            department = models.ForeignKey(Department, models.CASCADE, to_field="code")

        class EmployeeProfile(models.Model):
            employee = models.OneToOneField(Employee, models.CASCADE)

        class EmployeeInfo(models.Model):
            employee = models.OneToOneField(Employee, models.CASCADE)
            description = models.CharField(max_length=100)

        class EmployeeProfileAdmin(ModelAdmin):
            list_filter = [
                'employee__employeeinfo__description',
                'employee__department__code',
            ]

        ma = EmployeeProfileAdmin(EmployeeProfile, self.site)
        # Reverse OneToOneField
        self.assertIs(ma.lookup_allowed('employee__employeeinfo__description', 'test_value'), True)
        # OneToOneField and ForeignKey
        self.assertIs(ma.lookup_allowed('employee__department__code', 'test_value'), True) 

def test_abstract_parent_link(self):
        class A(models.Model):
            pass

        class B(A):
            a = models.OneToOneField('A', parent_link=True, on_delete=models.CASCADE)

            class Meta:
                abstract = True

        class C(B):
            pass

        self.assertIs(C._meta.parents[A], C._meta.get_field('a')) 

def _register_model(admin, model):
    if not hasattr(admin, 'revision_manager'):
        admin.revision_manager = default_revision_manager
    if not hasattr(admin, 'reversion_format'):
        admin.reversion_format = 'json'

    if not admin.revision_manager.is_registered(model):
        inline_fields = []
        for inline in getattr(admin, 'inlines', []):
            inline_model = inline.model
            if getattr(inline, 'generic_inline', False):
                ct_field = getattr(inline, 'ct_field', 'content_type')
                ct_fk_field = getattr(inline, 'ct_fk_field', 'object_id')
                for field in model._meta.many_to_many:
                    if isinstance(field, GenericRelation) and field.rel.to == inline_model and field.object_id_field_name == ct_fk_field and field.content_type_field_name == ct_field:
                        inline_fields.append(field.name)
                _autoregister(admin, inline_model)
            else:
                fk_name = getattr(inline, 'fk_name', None)
                if not fk_name:
                    for field in inline_model._meta.fields:
                        if isinstance(field, (models.ForeignKey, models.OneToOneField)) and issubclass(model, field.rel.to):
                            fk_name = field.name
                _autoregister(admin, inline_model, follow=[fk_name])
                if not inline_model._meta.get_field(fk_name).rel.is_hidden():
                    accessor = inline_model._meta.get_field(
                        fk_name).related.get_accessor_name()
                    inline_fields.append(accessor)
        _autoregister(admin, model, inline_fields) 

def test_create_model_inheritance(self):
        """
        Tests the CreateModel operation on a multi-table inheritance setup.
        """
        project_state = self.set_up_test_model("test_crmoih")
        # Test the state alteration
        operation = migrations.CreateModel(
            "ShetlandPony",
            [
                ('pony_ptr', models.OneToOneField(
                    'test_crmoih.Pony',
                    models.CASCADE,
                    auto_created=True,
                    primary_key=True,
                    to_field='id',
                    serialize=False,
                )),
                ("cuteness", models.IntegerField(default=1)),
            ],
        )
        new_state = project_state.clone()
        operation.state_forwards("test_crmoih", new_state)
        self.assertIn(("test_crmoih", "shetlandpony"), new_state.models)
        # Test the database alteration
        self.assertTableNotExists("test_crmoih_shetlandpony")
        with connection.schema_editor() as editor:
            operation.database_forwards("test_crmoih", editor, project_state, new_state)
        self.assertTableExists("test_crmoih_shetlandpony")
        # And test reversal
        with connection.schema_editor() as editor:
            operation.database_backwards("test_crmoih", editor, new_state, project_state)
        self.assertTableNotExists("test_crmoih_shetlandpony") 

def __str__(self):
        return self.title


# order_with_respect_to points to a model with a OneToOneField primary key. 

def _register_model(admin, model):
    if not hasattr(admin, 'reversion_format'):
        admin.reversion_format = 'json'

    if not is_registered(model):
        inline_fields = []
        for inline in getattr(admin, 'inlines', []):
            inline_model = inline.model
            if getattr(inline, 'generic_inline', False):
                ct_field = getattr(inline, 'ct_field', 'content_type')
                ct_fk_field = getattr(inline, 'ct_fk_field', 'object_id')
                for field in model._meta.many_to_many:
                    if isinstance(field, GenericRelation) \
                            and field.rel.to == inline_model \
                            and field.object_id_field_name == ct_fk_field \
                            and field.content_type_field_name == ct_field:
                        inline_fields.append(field.name)
                _autoregister(admin, inline_model)
            else:
                fk_name = getattr(inline, 'fk_name', None)
                if not fk_name:
                    for field in inline_model._meta.fields:
                        if isinstance(field, (models.ForeignKey, models.OneToOneField)) and issubclass(model, field.remote_field.model):
                            fk_name = field.name
                _autoregister(admin, inline_model, follow=[fk_name])
                if not inline_model._meta.get_field(fk_name).remote_field.is_hidden():
                    accessor = inline_model._meta.get_field(fk_name).remote_field.get_accessor_name()
                    inline_fields.append(accessor)
        _autoregister(admin, model, inline_fields) 

def test_make_non_sealable_model_subclass(self):
        class Foo(models.Model):
            pass

        class Bar(models.Model):
            foo = models.BooleanField(default=False)
            fk = models.ForeignKey(Foo, models.CASCADE, related_name='fk_bar')
            o2o = models.OneToOneField(Foo, models.CASCADE, related_name='o2o_bar')
            m2m = models.ManyToManyField(Foo, related_name='m2m_bar')

        make_model_sealable(Bar)

        # Forward fields descriptors should have been made sealable.
        self.assertIsInstance(Bar.foo, SealableDeferredAttribute)
        self.assertIsInstance(Bar.fk, SealableForwardManyToOneDescriptor)
        self.assertIsInstance(Bar.o2o, SealableForwardOneToOneDescriptor)
        self.assertIsInstance(Bar.m2m, SealableManyToManyDescriptor)

        # But not the remote fields.
        self.assertNotIsInstance(Foo.fk_bar, SealableReverseManyToOneDescriptor)
        self.assertNotIsInstance(Foo.o2o_bar, SealableReverseOneToOneDescriptor)
        self.assertNotIsInstance(Foo.m2m_bar, SealableManyToManyDescriptor)

        # Should seal local related objects.
        make_model_sealable(Foo)
        self.assertIsInstance(Foo.fk_bar, SealableReverseManyToOneDescriptor)
        self.assertIsInstance(Foo.o2o_bar, SealableReverseOneToOneDescriptor)
        self.assertIsInstance(Foo.m2m_bar, SealableManyToManyDescriptor) 

def _register_model(admin, model):
    if not hasattr(admin, 'reversion_format'):
        admin.reversion_format = 'json'

    if not is_registered(model):
        inline_fields = []
        for inline in getattr(admin, 'inlines', []):
            inline_model = inline.model
            if getattr(inline, 'generic_inline', False):
                ct_field = getattr(inline, 'ct_field', 'content_type')
                ct_fk_field = getattr(inline, 'ct_fk_field', 'object_id')
                for field in model._meta.many_to_many:
                    if isinstance(field, GenericRelation) \
                            and field.rel.to == inline_model \
                            and field.object_id_field_name == ct_fk_field \
                            and field.content_type_field_name == ct_field:
                        inline_fields.append(field.name)
                _autoregister(admin, inline_model)
            else:
                fk_name = getattr(inline, 'fk_name', None)
                if not fk_name:
                    for field in inline_model._meta.fields:
                        if isinstance(field, (models.ForeignKey, models.OneToOneField)) and issubclass(model, field.remote_field.model):
                            fk_name = field.name
                _autoregister(admin, inline_model, follow=[fk_name])
                if not inline_model._meta.get_field(fk_name).remote_field.is_hidden():
                    accessor = inline_model._meta.get_field(fk_name).remote_field.get_accessor_name()
                    inline_fields.append(accessor)
        _autoregister(admin, model, inline_fields) 

def test_missing_parent_link(self):
        msg = 'Add parent_link=True to invalid_models_tests.ParkingLot.parent.'
        with self.assertRaisesMessage(ImproperlyConfigured, msg):
            class Place(models.Model):
                pass

            class ParkingLot(Place):
                parent = models.OneToOneField(Place, models.CASCADE) 

def test_create_model_inheritance(self):
        """
        Tests the CreateModel operation on a multi-table inheritance setup.
        """
        project_state = self.set_up_test_model("test_crmoih")
        # Test the state alteration
        operation = migrations.CreateModel(
            "ShetlandPony",
            [
                ('pony_ptr', models.OneToOneField(
                    'test_crmoih.Pony',
                    models.CASCADE,
                    auto_created=True,
                    primary_key=True,
                    to_field='id',
                    serialize=False,
                )),
                ("cuteness", models.IntegerField(default=1)),
            ],
        )
        new_state = project_state.clone()
        operation.state_forwards("test_crmoih", new_state)
        self.assertIn(("test_crmoih", "shetlandpony"), new_state.models)
        # Test the database alteration
        self.assertTableNotExists("test_crmoih_shetlandpony")
        with connection.schema_editor() as editor:
            operation.database_forwards("test_crmoih", editor, project_state, new_state)
        self.assertTableExists("test_crmoih_shetlandpony")
        # And test reversal
        with connection.schema_editor() as editor:
            operation.database_backwards("test_crmoih", editor, new_state, project_state)
        self.assertTableNotExists("test_crmoih_shetlandpony") 

def add_fields(self, form, index):
        """Add a hidden field for the object's primary key."""
        from django.db.models import AutoField, OneToOneField, ForeignKey
        self._pk_field = pk = self.model._meta.pk
        # If a pk isn't editable, then it won't be on the form, so we need to
        # add it here so we can tell which object is which when we get the
        # data back. Generally, pk.editable should be false, but for some
        # reason, auto_created pk fields and AutoField's editable attribute is
        # True, so check for that as well.

        def pk_is_not_editable(pk):
            return ((not pk.editable) or (pk.auto_created or isinstance(pk, AutoField))
                or (pk.rel and pk.rel.parent_link and pk_is_not_editable(pk.rel.to._meta.pk)))
        if pk_is_not_editable(pk) or pk.name not in form.fields:
            if form.is_bound:
                # If we're adding the related instance, ignore its primary key
                # as it could be an auto-generated default which isn't actually
                # in the database.
                pk_value = None if form.instance._state.adding else form.instance.pk
            else:
                try:
                    if index is not None:
                        pk_value = self.get_queryset()[index].pk
                    else:
                        pk_value = None
                except IndexError:
                    pk_value = None
            if isinstance(pk, OneToOneField) or isinstance(pk, ForeignKey):
                qs = pk.rel.to._default_manager.get_queryset()
            else:
                qs = self.model._default_manager.get_queryset()
            qs = qs.using(form.instance._state.db)
            if form._meta.widgets:
                widget = form._meta.widgets.get(self._pk_field.name, HiddenInput)
            else:
                widget = HiddenInput
            form.fields[self._pk_field.name] = ModelChoiceField(qs, initial=pk_value, required=False, widget=widget)
        super(BaseModelFormSet, self).add_fields(form, index) 

def test_missing_parent_link(self):
        msg = 'Add parent_link=True to invalid_models_tests.ParkingLot.parent.'
        with self.assertRaisesMessage(ImproperlyConfigured, msg):
            class Place(models.Model):
                pass

            class ParkingLot(Place):
                parent = models.OneToOneField(Place, models.CASCADE) 

def test_create_model_inheritance(self):
        """
        Tests the CreateModel operation on a multi-table inheritance setup.
        """
        project_state = self.set_up_test_model("test_crmoih")
        # Test the state alteration
        operation = migrations.CreateModel(
            "ShetlandPony",
            [
                ('pony_ptr', models.OneToOneField(
                    'test_crmoih.Pony',
                    models.CASCADE,
                    auto_created=True,
                    primary_key=True,
                    to_field='id',
                    serialize=False,
                )),
                ("cuteness", models.IntegerField(default=1)),
            ],
        )
        new_state = project_state.clone()
        operation.state_forwards("test_crmoih", new_state)
        self.assertIn(("test_crmoih", "shetlandpony"), new_state.models)
        # Test the database alteration
        self.assertTableNotExists("test_crmoih_shetlandpony")
        with connection.schema_editor() as editor:
            operation.database_forwards("test_crmoih", editor, project_state, new_state)
        self.assertTableExists("test_crmoih_shetlandpony")
        # And test reversal
        with connection.schema_editor() as editor:
            operation.database_backwards("test_crmoih", editor, new_state, project_state)
        self.assertTableNotExists("test_crmoih_shetlandpony") 

def __str__(self):
        return self.title


# order_with_respect_to points to a model with a OneToOneField primary key. 

def _register_model(admin, model):
    if not hasattr(admin, 'reversion_format'):
        admin.reversion_format = 'json'

    if not is_registered(model):
        inline_fields = []
        for inline in getattr(admin, 'inlines', []):
            inline_model = inline.model
            if getattr(inline, 'generic_inline', False):
                ct_field = getattr(inline, 'ct_field', 'content_type')
                ct_fk_field = getattr(inline, 'ct_fk_field', 'object_id')
                for field in model._meta.many_to_many:
                    if isinstance(field, GenericRelation) \
                            and field.rel.to == inline_model \
                            and field.object_id_field_name == ct_fk_field \
                            and field.content_type_field_name == ct_field:
                        inline_fields.append(field.name)
                _autoregister(admin, inline_model)
            else:
                fk_name = getattr(inline, 'fk_name', None)
                if not fk_name:
                    for field in inline_model._meta.fields:
                        if isinstance(field, (models.ForeignKey, models.OneToOneField)) and issubclass(model, field.rel.to):
                            fk_name = field.name
                _autoregister(admin, inline_model, follow=[fk_name])
                if not inline_model._meta.get_field(fk_name).rel.is_hidden():
                    accessor = inline_model._meta.get_field(fk_name).remote_field.get_accessor_name()
                    inline_fields.append(accessor)
        _autoregister(admin, model, inline_fields) 

def test_on_conflict_nothing_foreign_primary_key():
    """Tests whether simple insert NOTHING works correctly when the primary key
    of a field is a foreign key with a custom name."""

    referenced_model = get_fake_model({})

    model = get_fake_model(
        {
            "parent": models.OneToOneField(
                referenced_model, primary_key=True, on_delete=models.CASCADE
            ),
            "cookies": models.CharField(max_length=255),
        }
    )

    referenced_obj = referenced_model.objects.create()

    # row does not conflict, new row should be created
    obj1 = model.objects.on_conflict(
        ["parent_id"], ConflictAction.NOTHING
    ).insert_and_get(parent_id=referenced_obj.pk, cookies="cheers")

    obj1.refresh_from_db()
    assert obj1.parent == referenced_obj
    assert obj1.cookies == "cheers"

    # row conflicts, no new row should be created
    obj2 = model.objects.on_conflict(
        ["parent_id"], ConflictAction.NOTHING
    ).insert_and_get(parent_id=referenced_obj.pk, cookies="choco")

    assert not obj2

    obj1.refresh_from_db()
    assert obj1.cookies == "cheers"
    assert model.objects.count() == 1 

def test_on_conflict_nothing_foreign_key_by_id():
    """Tests whether simple insert NOTHING works correctly when the potentially
    conflicting field is a foreign key specified as an id."""

    other_model = get_fake_model({})

    model = get_fake_model(
        {
            "other": models.OneToOneField(
                other_model, on_delete=models.CASCADE
            ),
            "data": models.CharField(max_length=255),
        }
    )

    other_obj = other_model.objects.create()

    # row does not conflict, new row should be created
    obj1 = model.objects.on_conflict(
        ["other_id"], ConflictAction.NOTHING
    ).insert_and_get(other_id=other_obj.pk, data="some data")

    assert obj1.other == other_obj
    assert obj1.data == "some data"

    obj1.refresh_from_db()
    assert obj1.other == other_obj
    assert obj1.data == "some data"

    # row conflicts, no new row should be created
    obj2 = model.objects.on_conflict(
        ["other_id"], ConflictAction.NOTHING
    ).insert_and_get(other_id=other_obj.pk, data="different data")

    assert not obj2
    assert model.objects.count() == 1

    obj1.refresh_from_db()
    assert obj1.other == other_obj
    assert obj1.data == "some data" 

def get_related_models(self, model):
        fields = model._meta.get_fields(include_hidden=True)
        def filter_fields(x):
            if any(map(lambda rel: isinstance(x, rel), [
                models.OneToOneRel,
                models.OneToOneField,
                models.ManyToOneRel,
                models.ManyToManyField,
                models.ManyToManyRel
            ])):
                return True
            return False
        return list(map(lambda x: x.related_model, filter(filter_fields, fields))) 

def __init__(self, to, on_delete=models.DO_NOTHING, to_field=None, db_constraint=False, **kwargs):
        super(OneToOneField, self).__init__(to, on_delete, to_field, db_constraint=db_constraint, **kwargs) 

def _register_model(admin, model):
    if not hasattr(admin, 'reversion_format'):
        admin.reversion_format = 'json'

    if not is_registered(model):
        inline_fields = []
        for inline in getattr(admin, 'inlines', []):
            inline_model = inline.model
            if getattr(inline, 'generic_inline', False):
                ct_field = getattr(inline, 'ct_field', 'content_type')
                ct_fk_field = getattr(inline, 'ct_fk_field', 'object_id')
                for field in model._meta.many_to_many:
                    if isinstance(field, GenericRelation) \
                            and field.rel.to == inline_model \
                            and field.object_id_field_name == ct_fk_field \
                            and field.content_type_field_name == ct_field:
                        inline_fields.append(field.name)
                _autoregister(admin, inline_model)
            else:
                fk_name = getattr(inline, 'fk_name', None)
                if not fk_name:
                    for field in inline_model._meta.fields:
                        if isinstance(field, (models.ForeignKey, models.OneToOneField)) and issubclass(model, field.rel.to):
                            fk_name = field.name
                _autoregister(admin, inline_model, follow=[fk_name])
                if not inline_model._meta.get_field(fk_name).rel.is_hidden():
                    accessor = inline_model._meta.get_field(fk_name).remote_field.get_accessor_name()
                    inline_fields.append(accessor)
        _autoregister(admin, model, inline_fields) 

def _register_model(admin, model):
    if not hasattr(admin, 'reversion_format'):
        admin.reversion_format = 'json'

    if not is_registered(model):
        inline_fields = []
        for inline in getattr(admin, 'inlines', []):
            inline_model = inline.model
            if getattr(inline, 'generic_inline', False):
                ct_field = getattr(inline, 'ct_field', 'content_type')
                ct_fk_field = getattr(inline, 'ct_fk_field', 'object_id')
                for field in model._meta.many_to_many:
                    if isinstance(field, GenericRelation) \
                            and field.rel.to == inline_model \
                            and field.object_id_field_name == ct_fk_field \
                            and field.content_type_field_name == ct_field:
                        inline_fields.append(field.name)
                _autoregister(admin, inline_model)
            else:
                fk_name = getattr(inline, 'fk_name', None)
                if not fk_name:
                    for field in inline_model._meta.fields:
                        if isinstance(field, (models.ForeignKey, models.OneToOneField)) and issubclass(model, field.remote_field.model):
                            fk_name = field.name
                _autoregister(admin, inline_model, follow=[fk_name])
                if not inline_model._meta.get_field(fk_name).remote_field.is_hidden():
                    accessor = inline_model._meta.get_field(fk_name).remote_field.get_accessor_name()
                    inline_fields.append(accessor)
        _autoregister(admin, model, inline_fields) 

def _register_model(admin, model):
    if not hasattr(admin, 'reversion_format'):
        admin.reversion_format = 'json'

    if not is_registered(model):
        inline_fields = []
        for inline in getattr(admin, 'inlines', []):
            inline_model = inline.model
            if getattr(inline, 'generic_inline', False):
                ct_field = getattr(inline, 'ct_field', 'content_type')
                ct_fk_field = getattr(inline, 'ct_fk_field', 'object_id')
                for field in model._meta.many_to_many:
                    if isinstance(field, GenericRelation) \
                            and field.rel.to == inline_model \
                            and field.object_id_field_name == ct_fk_field \
                            and field.content_type_field_name == ct_field:
                        inline_fields.append(field.name)
                _autoregister(admin, inline_model)
            else:
                fk_name = getattr(inline, 'fk_name', None)
                if not fk_name:
                    for field in inline_model._meta.fields:
                        if isinstance(field, (models.ForeignKey, models.OneToOneField)) and issubclass(model, field.remote_field.model):
                            fk_name = field.name
                _autoregister(admin, inline_model, follow=[fk_name])
                if not inline_model._meta.get_field(fk_name).remote_field.is_hidden():
                    accessor = inline_model._meta.get_field(fk_name).remote_field.get_accessor_name()
                    inline_fields.append(accessor)
        _autoregister(admin, model, inline_fields) 

def add_fields(self, form, index):
        """Add a hidden field for the object's primary key."""
        from django.db.models import AutoField, OneToOneField, ForeignKey
        self._pk_field = pk = self.model._meta.pk
        # If a pk isn't editable, then it won't be on the form, so we need to
        # add it here so we can tell which object is which when we get the
        # data back. Generally, pk.editable should be false, but for some
        # reason, auto_created pk fields and AutoField's editable attribute is
        # True, so check for that as well.
        def pk_is_not_editable(pk):
            return ((not pk.editable) or (pk.auto_created or isinstance(pk, AutoField))
                or (pk.rel and pk.rel.parent_link and pk_is_not_editable(pk.rel.to._meta.pk)))
        if pk_is_not_editable(pk) or pk.name not in form.fields:
            if form.is_bound:
                pk_value = form.instance.pk
            else:
                try:
                    if index is not None:
                        pk_value = self.get_queryset()[index].pk
                    else:
                        pk_value = None
                except IndexError:
                    pk_value = None
            if isinstance(pk, OneToOneField) or isinstance(pk, ForeignKey):
                qs = pk.rel.to._default_manager.get_query_set()
            else:
                qs = self.model._default_manager.get_query_set()
            qs = qs.using(form.instance._state.db)
            form.fields[self._pk_field.name] = ModelChoiceField(qs, initial=pk_value, required=False, widget=HiddenInput)
        super(BaseModelFormSet, self).add_fields(form, index) 

def __init__(self, to, on_delete=models.DO_NOTHING, to_field=None, db_constraint=False, **kwargs):
        super(OneToOneField, self).__init__(to, on_delete, to_field, db_constraint=db_constraint, **kwargs) 

def test_form(self):
        field = self.get_field(AbstractFormSetting, "form")
        self.assertModelField(field, models.OneToOneField)
        self.assertEqual(field.remote_field.model, "wagtailstreamforms.Form")
        self.assertEqual(field.remote_field.on_delete, models.CASCADE)
        self.assertEqual(field.remote_field.related_name, "advanced_settings") 

def _register_model(admin, model):
    if not hasattr(admin, 'reversion_format'):
        admin.reversion_format = 'json'

    if not is_registered(model):
        inline_fields = []
        for inline in getattr(admin, 'inlines', []):
            inline_model = inline.model
            if getattr(inline, 'generic_inline', False):
                ct_field = getattr(inline, 'ct_field', 'content_type')
                ct_fk_field = getattr(inline, 'ct_fk_field', 'object_id')
                for field in model._meta.many_to_many:
                    if isinstance(field, GenericRelation) \
                            and field.rel.to == inline_model \
                            and field.object_id_field_name == ct_fk_field \
                            and field.content_type_field_name == ct_field:
                        inline_fields.append(field.name)
                _autoregister(admin, inline_model)
            else:
                fk_name = getattr(inline, 'fk_name', None)
                if not fk_name:
                    for field in inline_model._meta.fields:
                        if isinstance(field, (models.ForeignKey, models.OneToOneField)) and issubclass(model, field.remote_field.model):
                            fk_name = field.name
                _autoregister(admin, inline_model, follow=[fk_name])
                if not inline_model._meta.get_field(fk_name).remote_field.is_hidden():
                    accessor = inline_model._meta.get_field(fk_name).remote_field.get_accessor_name()
                    inline_fields.append(accessor)
        _autoregister(admin, model, inline_fields) 

def guess_field_formatters(self, faker):
        """
        Gets the formatter methods for each field using the guessers
        or related object fields
        :param faker: Faker factory object
        """
        formatters = {}
        name_guesser = NameGuesser(faker)
        field_type_guesser = FieldTypeGuesser(faker)

        for field in self.model._meta.fields:

            field_name = field.name

            if field.primary_key:
                continue

            if field.get_default():
                formatters[field_name] = field.get_default()
                continue

            if isinstance(field, (ForeignKey, ManyToManyField, OneToOneField)):
                formatters[field_name] = self.build_relation(field, field.related_model)
                continue

            if not field.choices:
                formatter = name_guesser.guess_format(field_name)
                if formatter:
                    formatters[field_name] = formatter
                    continue

            formatter = field_type_guesser.guess_format(field)
            if formatter:
                formatters[field_name] = formatter
                continue

        return formatters