feat(apis_metainfo): replace Uri.root_object with GenericForeignKey

The `Uri` should allow to point to any model instance, not only to models
that inherit from `RootObject`. Therefore we introduce a
GenericForeignKey. The migration copies the values of existing
`root_object` pointers to the generic foreign key. The `root_object`
field is then dropped from the model.

apis_core/apis_metainfo/filtersets.py

@@ -5,6 +5,3 @@
 
 class UriFilterSet(GenericFilterSet):
     uri = django_filters.CharFilter(lookup_expr="icontains")
-
-    class Meta(GenericFilterSet.Meta):
-        exclude = ["root_object"]

apis_core/apis_metainfo/migrations/0015_uri_content_type_uri_object_id.py

@@ -0,0 +1,49 @@
+# Generated by Django 5.1.1 on 2024-11-29 08:31
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+def copy_root_object(apps, schema_editor):
+    Uri = apps.get_model("apis_metainfo", "Uri")
+    RootObject = apps.get_model("apis_metainfo", "RootObject")
+    for uri in Uri.objects.all():
+        if uri.root_object_id:
+            root_object = RootObject.objects.get(pk=uri.root_object_id)
+            uri.content_type_id = root_object.self_contenttype_id
+            uri.object_id = root_object.id
+            uri.save()
+
+
+def reverse_copy_root_object(apps, schema_editor):
+    Uri = apps.get_model("apis_metainfo", "Uri")
+    for uri in Uri.objects.all():
+        if uri.content_type_id and uri.object_id:
+            uri.root_object_id = uri.object_id
+            uri.save()
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("apis_metainfo", "0014_remove_uri_domain_remove_uri_loaded_and_more"),
+        ("contenttypes", "0002_remove_content_type_name"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="uri",
+            name="content_type",
+            field=models.ForeignKey(
+                null=True,
+                on_delete=django.db.models.deletion.CASCADE,
+                to="contenttypes.contenttype",
+            ),
+        ),
+        migrations.AddField(
+            model_name="uri",
+            name="object_id",
+            field=models.PositiveIntegerField(null=True),
+        ),
+        migrations.RunPython(copy_root_object, reverse_copy_root_object),
+        migrations.RemoveField(model_name="uri", name="root_object"),
+    ]

apis_core/apis_metainfo/models.py

@@ -1,5 +1,6 @@
 from urllib.parse import urlsplit
 
+from django.contrib.contenttypes.fields import GenericForeignKey
 from django.contrib.contenttypes.models import ContentType
 from django.core.exceptions import ImproperlyConfigured, ValidationError
 from django.db import models
@@ -66,9 +67,9 @@ def get_queryset(self):
 
 class Uri(GenericModel, models.Model):
     uri = models.URLField(blank=True, null=True, unique=True, max_length=255)
-    root_object = InheritanceForeignKey(
-        RootObject, blank=True, null=True, on_delete=models.CASCADE
-    )
+    content_type = models.ForeignKey(ContentType, on_delete=models.CASCADE, null=True)
+    object_id = models.PositiveIntegerField(null=True)
+    content_object = GenericForeignKey()
 
     objects = UriManager()
 
@@ -79,9 +80,9 @@ def get_web_object(self):
         result = {
             "relation_pk": self.pk,
             "relation_type": "uri",
-            "related_root_object": self.root_object.name,
-            "related_root_object_url": self.root_object.get_absolute_url(),
-            "related_root_object_class_name": self.root_object.__class__.__name__.lower(),
+            "related_root_object": self.content_object.name,
+            "related_root_object_url": self.content_object.get_absolute_url(),
+            "related_root_object_class_name": self.content_object.__class__.__name__.lower(),
             "uri": self.uri,
         }
         return result
@@ -92,7 +93,7 @@ def save(self, *args, **kwargs):
 
     def clean(self):
         self.uri = clean_uri(self.uri)
-        if self.uri and not hasattr(self, "root_object"):
+        if self.uri and not hasattr(self, "content_object"):
             try:
                 definition, attributes = rdf.get_definition_and_attributes_from_uri(
                     self.uri
@@ -103,6 +104,8 @@ def clean(self):
                     obj = ct.model_class()(**attributes)
                     obj.save()
                     self.root_object = obj
+                    self.content_type = ContentType.objects.get_for_model(obj)
+                    self.object_id = obj.id
                 else:
                     raise ImproperlyConfigured(
                         f"{self.uri}: did not find matching rdf defintion"

apis_core/apis_metainfo/tables.py

@@ -1,5 +1,4 @@
 import django_tables2 as tables
-from django.db.models import F
 
 from apis_core.generic.tables import GenericTable
 
@@ -8,22 +7,16 @@
 
 class UriTable(GenericTable):
     entity = tables.TemplateColumn(
-        "<a href='{{ record.root_object.get_absolute_url }}'>{{ record.root_object }}</a>",
-        orderable=True,
+        "<a href='{{ record.content_object.get_absolute_url }}'>{{ record.content_object }}</a>",
+        orderable=False,
         verbose_name="related Entity",
     )
-    ent_type = tables.TemplateColumn(
-        "{{ record.root_object.self_contenttype.model }}",
+    content_type = tables.TemplateColumn(
+        "{{ record.content_type.model }}",
         verbose_name="Entity Type",
     )
 
     class Meta(GenericTable.Meta):
         model = Uri
-        fields = ["id", "uri", "entity", "ent_type"]
+        fields = ["id", "uri", "entity", "content_type"]
         exclude = ("desc",)
-
-    def order_ent_type(self, queryset, is_descending):
-        queryset = queryset.annotate(
-            ent_type=F("root_object__self_contenttype__model")
-        ).order_by(("-" if is_descending else "") + "ent_type")
-        return (queryset, True)

apis_core/apis_metainfo/viewsets.py

@@ -28,7 +28,10 @@ def list(self, request):
         uri = params.pop("uri", None)
         if uri:
             u = get_object_or_404(Uri, uri=request.query_params.get("uri"))
-            r = u.root_object.get_api_detail_endpoint()
+            if u.content_object:
+                r = u.content_object.get_api_detail_endpoint()
+            else:
+                r = u.root_object.get_api_detail_endpoint()
             if params:
                 r += "?" + QueryDict.from_keys(params).urlencode()
             return HttpResponseRedirect(r)