Construct model only based on data without overwriting existing data.

Author: adamghill

conftest.py

@@ -14,6 +14,7 @@ def pytest_configure():
 
     installed_apps = [
         "example.coffee.apps.Config",
+        "example.books.apps.Config",
     ]
 
     unicorn_settings = {

django_unicorn/serializer.py

@@ -39,7 +39,7 @@ def _parse_field_values_from_string(model: Model) -> None:
     """
     Convert the model fields' value to match the field type if appropriate.
 
-    This is mostly to deal field string values that will get saved as a date-related field.
+    This is mostly to deal with field string values that will get saved as a date-related field.
     """
 
     for field in model._meta.fields:

django_unicorn/views/utils.py

@@ -1,6 +1,6 @@
 import logging
 from dataclasses import is_dataclass
-from typing import Any, Union
+from typing import Any, Dict, Set, Union
 
 from django.db.models import Model, QuerySet
 
@@ -199,10 +199,38 @@ class TestComponent(UnicornView):
 
         for (idx, model) in enumerate(queryset._result_cache):
             if model.pk == model_value.get("pk"):
-                queryset._result_cache[idx] = model_type(**model_value)
+                constructed_model = _construct_model(
+                    model_type, model_value, constructed_models
+                )
+                queryset._result_cache[idx] = constructed_model
                 model_found = True
 
         if not model_found:
-            queryset._result_cache.append(model_type(**model_value))
+            constructed_model = _construct_model(
+                model_type, model_value, constructed_models
+            )
+            queryset._result_cache.append(constructed_model)
 
     return queryset
+
+
+def _construct_model(model_type, model_data: Dict):
+    if not model_data:
+        return None
+
+    model = model_type()
+
+    for field_name in model_data.keys():
+        for field in model._meta.fields:
+            if field.name == field_name or (field_name == "pk" and field.primary_key):
+                # if field.is_relation:
+                #     related_model = _construct_model(
+                #         field.model, model_data[field_name]
+                #     )
+                #     setattr(model, field.name, related_model)
+                # else:
+
+                setattr(model, field.name, model_data[field_name])
+                break
+
+    return model

example/books/__init__.py

@@ -0,0 +1 @@
+default_app_config = "books.apps.Config"

example/books/apps.py

@@ -0,0 +1,5 @@
+from django.apps import AppConfig
+
+
+class Config(AppConfig):
+    name = "example.books"

example/books/models.py

@@ -1,7 +1,11 @@
-from django.db.models import Model
-from django.db.models.fields import CharField, DateField
+from django.db import models
 
 
-class Book(Model):
-    title = CharField(max_length=255)
-    date_published = DateField()
+class Book(models.Model):
+    title = models.CharField(max_length=255)
+    date_published = models.DateField()
+
+
+class Author(models.Model):
+    name = models.CharField(max_length=1024)
+    books = models.ManyToManyField(Book)

tests/serializer/test_dumps.py

@@ -1,17 +1,7 @@
 import json
 from decimal import Decimal
 
-from django.db.models import (
-    SET_NULL,
-    CharField,
-    DateField,
-    DateTimeField,
-    DurationField,
-    ForeignKey,
-    Model,
-    TimeField,
-)
-from django.db.models.fields import CharField
+from django.db import models
 from django.utils.timezone import now
 
 import pytest
@@ -21,16 +11,16 @@
 from example.coffee.models import Flavor
 
 
-class SimpleTestModel(Model):
-    name = CharField(max_length=10)
+class SimpleTestModel(models.Model):
+    name = models.CharField(max_length=10)
 
     class Meta:
         app_label = "tests"
 
 
-class ComplicatedTestModel(Model):
-    name = CharField(max_length=10)
-    parent = ForeignKey("self", blank=True, null=True, on_delete=SET_NULL)
+class ComplicatedTestModel(models.Model):
+    name = models.CharField(max_length=10)
+    parent = models.ForeignKey("self", blank=True, null=True, on_delete=models.SET_NULL)
 
     class Meta:
         app_label = "tests"
@@ -179,7 +169,7 @@ def test_model_foreign_key():
     assert expected == actual
 
 
-def test_model_foreign_key_recurive_parents():
+def test_model_foreign_key_recursive_parent():
     test_model_one = ComplicatedTestModel(id=1, name="abc")
     test_model_two = ComplicatedTestModel(id=2, name="def", parent=test_model_one)
     test_model_one.parent = test_model_two

tests/views/utils/test_set_property_from_data.py

@@ -138,6 +138,15 @@ def test_set_property_from_data_queryset_none_with_typehint():
     component_queryset_field_asserts(component, "queryset_with_typehint")
 
 
+def test_set_property_from_data_queryset_parent():
+    component = FakeQuerySetComponent(component_name="test", component_id="12345678")
+    assert component.queryset_with_typehint is None
+
+    set_property_from_data(component, "queryset_with_typehint", [{"name": "test-qs"}])
+
+    component_queryset_field_asserts(component, "queryset_with_typehint")
+
+
 def test_set_property_from_data_all_querysets():
     component = FakeAllQuerySetComponent(component_name="test", component_id="12345678")