Introduce method to_django turning obj into django model obj

.gitignore

@@ -135,3 +135,4 @@ dmypy.json
 
 # Not necessary for libs, see https://github.com/python-poetry/poetry/issues/7488
 poetry.lock
+notes.md

djantic/main.py

@@ -124,6 +124,7 @@ def __new__(mcs, name: str, bases: tuple, namespace: dict, **kwargs):
                     getattr(model_field[1], "alias", None) or field_name: field_name
                     for field_name, model_field in field_values.items()
                 }
+
                 model_schema = create_model(
                     name,
                     __base__=cls,
@@ -251,7 +252,29 @@ def from_orm(cls, *args, **kwargs):
         return cls.from_django(*args, **kwargs)
 
     @classmethod
-    def from_django(cls, objs, many=False, context={}, dump=False):
+    def to_django(cls, objs, many=False, validate=True):
+        Model = cls.model_config["model"]
+        if many:
+            # TODO, support for generators, possibly return generator.
+            is_not_dict = False if isinstance(objs[0], dict) else True
+            django_objs = []
+            for data in objs:
+                obj = Model(**data.dict()) if is_not_dict else Model(**data)
+                if validate:
+                    obj.clean_fields()
+                django_objs.append(obj)
+            return django_objs
+
+        if not isinstance(objs, dict):
+            objs = objs.dict()
+
+        obj = Model(**objs)
+        if validate:
+            obj.clean_fields()
+        return obj
+
+    @classmethod
+    def from_django(cls, objs, many=False, context={}):
         # TODO is context really passed into model_validate, test this
         cls.context = context
         if many:

tests/test_to_django.py

@@ -0,0 +1,97 @@
+import pytest
+from testapp.models import User
+from django.core.exceptions import ValidationError
+
+from pydantic import ConfigDict
+from djantic import ModelSchema
+
+
+@pytest.fixture
+def user():
+    user = User.objects.create(
+        first_name="Jordan", last_name="Eremieff", email="[email protected]"
+    )
+    return user
+
+
+@pytest.mark.django_db
+def test_to_django_validation_failure(user):
+    """
+    An incomplete schema throws a ValidationError
+    """
+
+    class UserSchema(ModelSchema):
+        model_config = ConfigDict(model=User, include=["id", "first_name"])
+
+    schema = UserSchema.from_django(user)
+
+    with pytest.raises(ValidationError):
+        UserSchema.to_django(schema.model_dump())
+
+    with pytest.raises(ValidationError):
+        UserSchema.to_django(schema)
+
+
+@pytest.mark.django_db
+def test_validate_false(user):
+    """
+    Optionally you can choose to not validate in to django,
+    you may then need to add more fields for the object to be valid
+    """
+
+    class UserSchema(ModelSchema):
+        model_config = ConfigDict(model=User, include=["id", "first_name"])
+
+    schema = UserSchema.from_django(user)
+
+    obj = UserSchema.to_django(schema, validate=False)
+
+    assert obj.email != user.email, "No email in schema, so is not added in object"
+    assert obj.id == user.id
+    assert obj.first_name == user.first_name
+
+
+@pytest.mark.django_db
+def test_many_objects(user):
+    """Test many objects"""
+    class UserSchema(ModelSchema):
+        model_config = ConfigDict(model=User)
+
+    schema = UserSchema.from_django(user)
+    obj_schema = UserSchema.to_django([schema, schema], many=True)
+
+    assert len(obj_schema) == 2
+    assert obj_schema[0].id == user.id
+    assert obj_schema[1].id == user.id
+
+
+@pytest.mark.django_db
+def test_invalid_many_objs(user):
+    """Validation works as expected using many objs"""
+    class UserSchema(ModelSchema):
+        model_config = ConfigDict(model=User, include=["id"])
+
+    schema = UserSchema.from_django(user)
+    with pytest.raises(ValidationError):
+        UserSchema.to_django([schema], many=True)
+
+
+@pytest.mark.django_db
+def test_with_foreign_key_models():
+    pass
+
+
+@pytest.mark.django_db
+def test_successful_transform(user):
+    """A successful transform from dict/schema to django obj"""
+
+    class UserSchema(ModelSchema):
+        model_config = ConfigDict(model=User)
+
+    schema = UserSchema.from_django(user)
+
+    obj_dump = UserSchema.to_django(schema.model_dump())
+    obj_schema = UserSchema.to_django(schema)
+
+    assert user == obj_dump
+    assert user == obj_schema