fix computed fk field handling (#155)

Fix for Issue #155

Author: jerch

computedfields/resolver.py

@@ -195,7 +195,7 @@ def extract_computed_models(self) -> Dict[Type[Model], Dict[str, IComputedField]
                 raise ResolverException(f'{model} is not a subclass of ComputedFieldsModel')
             computed_models[model] = {}
             for field in computedfields:
-                computed_models[model][field.attname] = field
+                computed_models[model][field.name] = field
 
         return computed_models
 

example/example/settings.py

@@ -92,11 +92,11 @@
     DATABASES = {
         'default': {
             'ENGINE': 'django.db.backends.postgresql',
-            'NAME': 'postgres',
-            'USER': 'postgres',
-            'PASSWORD': 'mysecretpassword',
-            'HOST': 'localhost',
-            'PORT': 5432,
+            'NAME': os.environ.get('DATABASE_NAME', 'postgres'),
+            'USER': os.environ.get('DATABASE_USER', 'postgres'),
+            'PASSWORD': os.environ.get('DATABASE_PASSWORD', 'mysecretpassword'),
+            'HOST': os.environ.get('DATABASE_HOST', 'localhost'),
+            'PORT': int(os.environ.get('DATABASE_PORT', '5432')),
         }
     }
 

example/test_full/models.py

@@ -1137,3 +1137,38 @@ def comp(self):
 class RNM2MBar(models.Model):
     b = models.CharField(max_length=10)
     foos = models.ManyToManyField(RNM2MFoo, related_name='bars', related_query_name='bar')
+
+
+# Computed Foreign Key models
+## Base catalogues
+class CFKCatalogue1(models.Model):
+    name = models.CharField(max_length=10)
+
+class CFKCatalogue2(models.Model):
+    name = models.CharField(max_length=10)
+
+## Some data in catalogues
+class CFKData(ComputedFieldsModel):
+    c1name = models.CharField(max_length=10)
+    c2name = models.CharField(max_length=10)
+
+    @computed(models.ForeignKey(CFKCatalogue1, on_delete=models.CASCADE))
+    def c1(self):
+        return CFKCatalogue1.objects.get(name=self.c1name)
+
+    @computed(models.ForeignKey(CFKCatalogue2, on_delete=models.CASCADE))
+    def c2(self):
+        return CFKCatalogue2.objects.get(name=self.c2name)
+
+## Some data related to parent data in catalogues
+class CFKRelatedData(ComputedFieldsModel):
+    parent = models.ForeignKey(CFKData, on_delete=models.CASCADE)
+    value = models.CharField(max_length=10)
+
+    @computed(models.ForeignKey(CFKCatalogue1, on_delete=models.CASCADE))
+    def c1(self):
+        return self.parent.c1
+
+    @computed(models.ForeignKey(CFKCatalogue2, on_delete=models.CASCADE))
+    def c2(self):
+        return self.parent.c2

example/test_full/tests/test_computed_foreign_keys.py

@@ -0,0 +1,38 @@
+from django.test import TestCase
+from .. import models
+
+
+class ComputedForeignKeys(TestCase):
+    def setUp(self):
+        self.names = ['a', 'b', 'c', 'd', 'e', 'f']
+        for name in self.names:
+            models.CFKCatalogue1.objects.create(name='c1%s' % name)
+            models.CFKCatalogue2.objects.create(name='c2%s' % name)
+
+    def test_basic(self):
+        for c1 in models.CFKCatalogue1.objects.all():
+            for c2 in models.CFKCatalogue2.objects.all():
+                m = models.CFKData.objects.create(c1name=c1.name, c2name=c2.name)
+                self.assertEqual(m.c1, c1)
+                self.assertEqual(m.c2, c2)
+                for value in self.names:
+                    v = models.CFKRelatedData.objects.create(parent=m, value=value)
+                    self.assertEqual(v.c1, c1)
+                    self.assertEqual(v.c2, c2)
+
+    def test_cascade_delete(self):
+        for c1 in models.CFKCatalogue1.objects.all():
+            for c2 in models.CFKCatalogue2.objects.all():
+                m = models.CFKData.objects.create(c1name=c1.name, c2name=c2.name)
+                for value in self.names:
+                    models.CFKRelatedData.objects.create(parent=m, value=value)
+        self.assertGreater(models.CFKData.objects.all().count(), 0)
+        self.assertGreater(models.CFKRelatedData.objects.all().count(), 0)
+
+        # on deleting all CFKCatalogue1 instances
+        # CFKData and CFKRelatedData should drop to zero count
+        # due to cascade deletion
+        for c1 in models.CFKCatalogue1.objects.all():
+            c1.delete()
+        self.assertEqual(models.CFKData.objects.all().count(), 0)
+        self.assertEqual(models.CFKRelatedData.objects.all().count(), 0)