feat(generic): add a GenericModelCidocSerializer

This serializer should provide a basis for CIDOC serializers as well as
a fallback for models that have no CIDOC serializer configured.

apis_core/generic/serializers.py

@@ -1,7 +1,10 @@
 from django.contrib.contenttypes.models import ContentType
 from django.shortcuts import get_object_or_404
+from rdflib import Graph, Literal, Namespace, URIRef
+from rdflib.namespace import GEO, OWL, RDF, RDFS
 from rest_framework.reverse import reverse
 from rest_framework.serializers import (
+    BaseSerializer,
     CharField,
     HyperlinkedModelSerializer,
     HyperlinkedRelatedField,
@@ -10,6 +13,8 @@
     SerializerMethodField,
 )
 
+from apis_core.utils.settings import apis_base_uri, rdf_namespace_prefix
+
 
 class GenericHyperlinkedRelatedField(HyperlinkedRelatedField):
     def get_url(self, obj, view_name, request, format):
@@ -87,3 +92,61 @@ def get_content_type_key(self, obj) -> str:
     def get_content_type_name(self, obj) -> str:
         content_type = ContentType.objects.get_for_model(obj)
         return content_type.name
+
+
+class GenericModelCidocSerializer(BaseSerializer):
+    def __init__(self, *args, **kwargs):
+        self.base_uri = f"{apis_base_uri()}"
+        self.rdf_nsp_base = rdf_namespace_prefix()
+        self.appellation_nsp_prefix = f"{self.rdf_nsp_base}-appellation"
+        self.attr_nsp_prefix = f"{self.rdf_nsp_base}-attr"
+        super().__init__(*args, **kwargs)
+
+    def to_representation(self, instance):
+        g = Graph()
+        content_type = ContentType.objects.get_for_model(instance)
+
+        crm_namespace = Namespace("http://www.cidoc-crm.org/cidoc-crm/")
+        g.namespace_manager.bind("crm", crm_namespace, replace=True)
+        g.namespace_manager.bind("owl", OWL, replace=True)
+        g.namespace_manager.bind("geo", GEO, replace=True)
+
+        appellation_namespace = Namespace(f"{self.base_uri}/appellation/")
+        g.namespace_manager.bind(
+            self.appellation_nsp_prefix, appellation_namespace, replace=True
+        )
+        attributes_namespace = Namespace(f"{self.base_uri}/attributes/")
+        g.namespace_manager.bind(
+            self.attr_nsp_prefix, attributes_namespace, replace=True
+        )
+
+        self.instance_nsp_prefix = f"{self.rdf_nsp_base}-{content_type.name.lower()}"
+        instance_namespace = Namespace(self.base_uri + instance.get_listview_url())
+        g.namespace_manager.bind(self.instance_nsp_prefix, instance_namespace)
+
+        self.instance_uri = URIRef(instance_namespace[str(instance.id)])
+
+        # Add sameAs links
+        for uri in instance.uri_set.all():
+            uri_ref = URIRef(uri.uri)
+            g.add((self.instance_uri, OWL.sameAs, uri_ref))
+
+        # Add properties
+        self.appellation_uri = URIRef(appellation_namespace[str(instance.id)])
+        g.add(
+            (
+                self.appellation_uri,
+                RDF.type,
+                crm_namespace.E33_E41_Linguistic_Appellation,
+            )
+        )
+        g.add(
+            (
+                self.instance_uri,
+                crm_namespace.P1_is_identified_by,
+                self.appellation_uri,
+            )
+        )
+        g.add((self.appellation_uri, RDFS.label, Literal(str(instance))))
+
+        return g