policies/api: fix target returning pbm_uuid instead of proper primary key of the object

passbook/flows/forms.py

@@ -33,6 +33,7 @@ class FlowForm(forms.ModelForm):
         }
         widgets = {
             "name": forms.TextInput(),
+            "title": forms.TextInput(),
         }
 
 

passbook/flows/migrations/0012_auto_20200830_1056.py

@@ -1,18 +0,0 @@
-# Generated by Django 3.1 on 2020-08-30 10:56
-
-from django.db import migrations, models
-
-
-class Migration(migrations.Migration):
-
-    dependencies = [
-        ("passbook_flows", "0011_flow_title"),
-    ]
-
-    operations = [
-        migrations.AlterField(
-            model_name="flow",
-            name="title",
-            field=models.TextField(blank=True, default=""),
-        ),
-    ]

passbook/flows/migrations/0012_auto_20200908_1542.py

@@ -0,0 +1,26 @@
+# Generated by Django 3.1.1 on 2020-09-08 15:42
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+import passbook.lib.models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("passbook_flows", "0011_flow_title"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="flowstagebinding",
+            name="stage",
+            field=passbook.lib.models.InheritanceForeignKey(
+                on_delete=django.db.models.deletion.CASCADE, to="passbook_flows.stage"
+            ),
+        ),
+        migrations.AlterField(
+            model_name="stage", name="name", field=models.TextField(unique=True),
+        ),
+    ]

passbook/flows/migrations/0013_auto_20200905_2142.py

@@ -1,16 +0,0 @@
-# Generated by Django 3.1.1 on 2020-09-05 21:42
-
-from django.db import migrations, models
-
-
-class Migration(migrations.Migration):
-
-    dependencies = [
-        ("passbook_flows", "0012_auto_20200830_1056"),
-    ]
-
-    operations = [
-        migrations.AlterField(
-            model_name="stage", name="name", field=models.TextField(unique=True),
-        ),
-    ]

passbook/flows/models.py

@@ -93,7 +93,7 @@ class Flow(SerializerModel, PolicyBindingModel):
     name = models.TextField()
     slug = models.SlugField(unique=True)
 
-    title = models.TextField(default="", blank=True)
+    title = models.TextField()
 
     designation = models.CharField(max_length=100, choices=FlowDesignation.choices)
 

passbook/flows/tests/test_transfer.py

@@ -35,6 +35,7 @@ class TestFlowTransfer(TransactionTestCase):
             slug="test",
             designation=FlowDesignation.AUTHENTICATION,
             name="Welcome to passbook!",
+            title="test",
         )
         FlowStageBinding.objects.update_or_create(
             target=flow, stage=login_stage, order=0,
@@ -64,6 +65,7 @@ class TestFlowTransfer(TransactionTestCase):
             slug="default-source-authentication-test",
             designation=FlowDesignation.AUTHENTICATION,
             name="Welcome to passbook!",
+            title="test",
         )
         PolicyBinding.objects.create(policy=flow_policy, target=flow, order=0)
 
@@ -122,6 +124,7 @@ class TestFlowTransfer(TransactionTestCase):
             name="default-enrollment-flow",
             slug="default-enrollment-flow-test",
             designation=FlowDesignation.ENROLLMENT,
+            title="test",
         )
 
         FlowStageBinding.objects.create(target=flow, stage=first_stage, order=0)

passbook/flows/transfer/exporter.py

@@ -47,6 +47,7 @@ class FlowExporter:
         pbm_uuids += FlowStageBinding.objects.filter(target=self.flow).values_list(
             "pbm_uuid", flat=True
         )
+        # Add policy objects first, so they are created first
         policies = Policy.objects.filter(bindings__in=pbm_uuids).select_related()
         for policy in policies:
             yield FlowBundleEntry.from_model(policy)

passbook/lib/api.py

@@ -0,0 +1,36 @@
+"""passbook API Helpers"""
+from django.core.exceptions import ObjectDoesNotExist
+from django.db.models.query import QuerySet
+from model_utils.managers import InheritanceQuerySet
+from rest_framework.serializers import ModelSerializer, PrimaryKeyRelatedField
+
+
+class InheritancePrimaryKeyRelatedField(PrimaryKeyRelatedField):
+    """rest_framework PrimaryKeyRelatedField which resolves
+    model_manager's InheritanceQuerySet"""
+
+    def get_queryset(self) -> QuerySet:
+        queryset = super().get_queryset()
+        if isinstance(queryset, InheritanceQuerySet):
+            return queryset.select_subclasses()
+        return queryset
+
+    def to_internal_value(self, data):
+        if self.pk_field is not None:
+            data = self.pk_field.to_internal_value(data)
+        try:
+            queryset = self.get_queryset()
+            if isinstance(queryset, InheritanceQuerySet):
+                return queryset.get_subclass(pk=data)
+            return queryset.get(pk=data)
+        except ObjectDoesNotExist:
+            self.fail("does_not_exist", pk_value=data)
+        except (TypeError, ValueError):
+            self.fail("incorrect_type", data_type=type(data).__name__)
+
+
+class InheritanceModelSerializer(ModelSerializer):
+    """rest_framework ModelSerializer which automatically uses InheritancePrimaryKeyRelatedField
+    for every primary key"""
+
+    serializer_related_field = InheritancePrimaryKeyRelatedField

passbook/policies/api.py

@@ -1,14 +1,52 @@
 """policy API Views"""
 from rest_framework.serializers import ModelSerializer, SerializerMethodField
+from rest_framework.utils.model_meta import get_field_info
 from rest_framework.viewsets import ModelViewSet, ReadOnlyModelViewSet
 
+from passbook.lib.api import InheritancePrimaryKeyRelatedField
 from passbook.policies.forms import GENERAL_FIELDS
-from passbook.policies.models import Policy, PolicyBinding
+from passbook.policies.models import Policy, PolicyBinding, PolicyBindingModel
 
 
 class PolicyBindingSerializer(ModelSerializer):
     """PolicyBinding Serializer"""
 
+    # Because we're not interested in the PolicyBindingModel's PK but rather the subclasses PK,
+    # we have to manually declare this field
+    target = InheritancePrimaryKeyRelatedField(
+        queryset=PolicyBindingModel.objects.all().select_subclasses(),
+        source="target.pk",
+        required=True,
+    )
+
+    def update(self, instance, validated_data):
+        info = get_field_info(instance)
+
+        # Simply set each attribute on the instance, and then save it.
+        # Note that unlike `.create()` we don't need to treat many-to-many
+        # relationships as being a special case. During updates we already
+        # have an instance pk for the relationships to be associated with.
+        m2m_fields = []
+        for attr, value in validated_data.items():
+            if attr in info.relations and info.relations[attr].to_many:
+                m2m_fields.append((attr, value))
+            else:
+                if attr == "target":
+                    instance.target_pk = value["pk"].pbm_uuid
+                else:
+                    setattr(instance, attr, value)
+
+        instance.save()
+
+        # Note that many-to-many fields are set after updating instance.
+        # Setting m2m fields triggers signals which could potentially change
+        # updated instance and we do not want it to collide with .update()
+        for attr, value in m2m_fields:
+            field = getattr(instance, attr)
+            field.set(value)
+
+        return instance
+
     class Meta:
 
         model = PolicyBinding

passbook/policies/migrations/0003_auto_20200908_1542.py

@@ -0,0 +1,25 @@
+# Generated by Django 3.1.1 on 2020-09-08 15:42
+
+import django.db.models.deletion
+from django.db import migrations
+
+import passbook.lib.models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("passbook_policies", "0002_auto_20200528_1647"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="policybinding",
+            name="target",
+            field=passbook.lib.models.InheritanceForeignKey(
+                on_delete=django.db.models.deletion.CASCADE,
+                related_name="+",
+                to="passbook_policies.policybindingmodel",
+            ),
+        ),
+    ]

swagger.yaml

@@ -6041,6 +6041,7 @@ definitions:
     required:
       - name
       - slug
+      - title
       - designation
     type: object
     properties:
@@ -6063,6 +6064,7 @@ definitions:
       title:
         title: Title
         type: string
+        minLength: 1
       designation:
         title: Designation
         type: string