✨ [open-zaak/open-notificaties#156] Support nested fields on kanaal k…

…enmerken

and support kenmerken for django-loose-fk fields

notifications_api_common/kanalen.py

@@ -2,17 +2,41 @@
 Provide notifications kanaal/exchange classes.
 """
 from collections import defaultdict
-from typing import Dict, Tuple
+from typing import Dict, cast
 
 from django.core.exceptions import FieldDoesNotExist, ImproperlyConfigured
-from django.db.models import Model
-from django.db.models.base import ModelBase
+from django.db.models import Field, Model
+
+from glom import glom
+from rest_framework.request import Request
+from vng_api_common.tests import reverse
 
 KANAAL_REGISTRY = set()
 
 
+def get_field(model: Model, field: str) -> Field:
+    """
+    Function to retrieve a field from a Model, can also be passed a path to a field
+    (e.g. `zaaktype.catalogus`)
+    """
+    if "." in field:
+        model_field = None
+        bits = field.split(".")
+        for i, part in enumerate(bits):
+            model_field = model._meta.get_field(part)
+            if fk_field := getattr(model_field, "fk_field", None):
+                model_field = model._meta.get_field(fk_field)
+            if i != len(bits):
+                model = cast(Model, model_field.related_model)
+        assert model_field, "Could not find field on model"
+        return model_field
+    return model._meta.get_field(field)
+
+
 class Kanaal:
-    def __init__(self, label: str, main_resource: ModelBase, kenmerken: Tuple = None):
+    def __init__(
+        self, label: str, main_resource: Model, kenmerken: tuple | None = None
+    ):
         self.label = label
         self.main_resource = main_resource
 
@@ -22,7 +46,7 @@ def __init__(self, label: str, main_resource: ModelBase, kenmerken: Tuple = None
         self.kenmerken = kenmerken or ()
         for kenmerk in self.kenmerken:
             try:
-                self.main_resource._meta.get_field(kenmerk)
+                get_field(self.main_resource, kenmerk)
             except FieldDoesNotExist as exc:
                 raise ImproperlyConfigured(
                     f"Kenmerk '{kenmerk}' does not exist on the model {main_resource}"
@@ -38,12 +62,22 @@ def __repr__(self):
             self.main_resource,
         )
 
-    def get_kenmerken(self, obj: Model, data: Dict = None) -> Dict:
+    def get_kenmerken(
+        self, obj: Model, data: dict | None = None, request: Request | None = None
+    ) -> Dict:
         data = data or {}
-        return {
-            kenmerk: data.get(kenmerk, getattr(obj, kenmerk))
-            for kenmerk in self.kenmerken
-        }
+        kenmerken = {}
+        for kenmerk in self.kenmerken:
+            value = data.get(kenmerk, glom(obj, kenmerk, default=""))
+            if isinstance(value, Model):
+                if _loose_fk_data := getattr(value, "_loose_fk_data", None):
+                    value = _loose_fk_data["url"]
+                else:
+                    value = reverse(value)
+                    if request:
+                        value = request.build_absolute_uri(value)
+            kenmerken[kenmerk] = value
+        return kenmerken
 
     def get_usage(self):
         return self.usage.items()
@@ -54,7 +88,7 @@ def description(self):
         kenmerken = [
             kenmerk_template.format(
                 kenmerk=kenmerk,
-                help_text=self.main_resource._meta.get_field(kenmerk).help_text,
+                help_text=get_field(self.main_resource, kenmerk).help_text,
             )
             for kenmerk in self.kenmerken
         ]

notifications_api_common/viewsets.py

@@ -136,7 +136,9 @@ def construct_message(self, data: dict, instance: models.Model = None) -> dict:
             "actie": self.action,
             "aanmaakdatum": timezone.now(),
             # each channel knows which kenmerken it has, so delegate this
-            "kenmerken": kanaal.get_kenmerken(main_object, main_object_data),
+            "kenmerken": kanaal.get_kenmerken(
+                main_object, main_object_data, request=self.request
+            ),
         }
 
         # let the serializer & render machinery shape the data the way it

setup.cfg

@@ -39,6 +39,7 @@ install_requires =
     djangorestframework>=3.12.0
     celery
     djangorestframework_camel_case>=1.2.0
+    glom
     gemma-zds-client>=0.15.0
     zgw-consumers
 tests_require =