Proof of concept of retrieving concept trees

arches_rdm/urls.py

@@ -15,5 +15,8 @@
 """
 from django.urls import path
 
+from arches_rdm.views import ConceptTreeView
 
-urlpatterns = []
+urlpatterns = [
+    path("concept_trees/", ConceptTreeView.as_view(), name="concept_trees"),
+]

arches_rdm/views/__init__.py

@@ -0,0 +1,139 @@
+from collections import defaultdict
+
+from django.contrib.postgres.expressions import ArraySubquery
+from django.db.models import CharField, F, OuterRef, Value
+from django.db.models.expressions import CombinedExpression, Func
+from django.utils.decorators import method_decorator
+from django.views.generic import View
+
+from arches.app.models.models import ResourceInstance, TileModel
+from arches.app.utils.decorators import group_required
+
+from arches.app.utils.response import JSONResponse
+
+TOP_CONCEPT_OF_NODE_AND_NODEGROUP = "bf73e5b9-4888-11ee-8a8d-11afefc4bff7"
+TOP_CONCEPT_OF_LOOKUP = f"data__{TOP_CONCEPT_OF_NODE_AND_NODEGROUP}"
+
+BROADER_NODE_AND_NODEGROUP = "bf73e5f5-4888-11ee-8a8d-11afefc4bff7"
+BROADER_LOOKUP = f"data__{BROADER_NODE_AND_NODEGROUP}"
+
+CONCEPT_LABEL_NODEGROUP = "bf73e616-4888-11ee-8a8d-11afefc4bff7"
+CONCEPT_LABEL_NODE = "bf73e695-4888-11ee-8a8d-11afefc4bff7"
+CONCEPT_LABEL_LOOKUP = f"data__{CONCEPT_LABEL_NODE}"
+
+SCHEME_LABEL_NODE_AND_NODEGROUP = "749a27cf-423c-11ee-8a8d-11afefc4bff7"
+SCHEME_LABEL_NODE = "749a27d5-423c-11ee-8a8d-11afefc4bff7"
+SCHEME_LABEL_LOOKUP = f"data__{SCHEME_LABEL_NODE}"
+
+CONCEPTS_GRAPH_ID = "bf73e576-4888-11ee-8a8d-11afefc4bff7"
+SCHEMES_GRAPH_ID = "56788995-423b-11ee-8a8d-11afefc4bff7"
+
+
+class JsonArrayElements(Func):
+    contains_subquery = True
+    function = "JSONB_ARRAY_ELEMENTS"
+
+
+@method_decorator(
+    group_required("RDM Administrator", raise_exception=True), name="dispatch"
+)
+class ConceptTreeView(View):
+    def __init__(self):
+        self.schemes = ResourceInstance.objects.none()
+        self.top_concepts = defaultdict(set)
+        self.narrower_concepts = defaultdict(set)  # str: str
+        self.labels = defaultdict(set)
+
+    @staticmethod
+    def resources_from_tiles(lookup_expression: str):
+        return CombinedExpression(
+            JsonArrayElements(F(lookup_expression)),
+            "->>",
+            Value("resourceId"),
+            output_field=CharField(),
+        )
+
+    @staticmethod
+    def labels_subquery(label_lookup):
+        if label_lookup == SCHEME_LABEL_LOOKUP:
+            # Annotating a ResourceInstance
+            outer = OuterRef("resourceinstanceid")
+            nodegroup_id = SCHEME_LABEL_NODE_AND_NODEGROUP
+        else:
+            # Annotating a Tile
+            outer = OuterRef("resourceinstance_id")
+            nodegroup_id = CONCEPT_LABEL_NODEGROUP
+
+        return ArraySubquery(
+            TileModel.objects.filter(
+                resourceinstance_id=outer, nodegroup_id=nodegroup_id
+            )
+            .values(label_lookup)
+        )
+
+    def top_concepts_map(self):
+        top_concept_of_tiles = (
+            TileModel.objects.filter(nodegroup_id=TOP_CONCEPT_OF_NODE_AND_NODEGROUP)
+            .annotate(top_concept_of=self.resources_from_tiles(TOP_CONCEPT_OF_LOOKUP))
+            .annotate(labels=self.labels_subquery(CONCEPT_LABEL_LOOKUP))
+            .values("resourceinstance_id", "top_concept_of", "labels")
+        )
+        for tile in top_concept_of_tiles:
+            resource_id: str = str(tile["resourceinstance_id"])
+            self.top_concepts[tile["top_concept_of"]].add(resource_id)
+            self.labels[resource_id] = tile["labels"]
+
+    def narrower_concepts_map(self):
+        broader_concept_tiles = (
+            TileModel.objects.filter(nodegroup_id=BROADER_NODE_AND_NODEGROUP)
+            .annotate(broader_concept=self.resources_from_tiles(BROADER_LOOKUP))
+            .annotate(labels=self.labels_subquery(CONCEPT_LABEL_LOOKUP))
+            .values("resourceinstance_id", "broader_concept", "labels")
+        )
+        for tile in broader_concept_tiles:
+            resource_id: str = str(tile["resourceinstance_id"])
+            self.narrower_concepts[tile["broader_concept"]].add(resource_id)
+            self.labels[resource_id] = tile["labels"]
+
+    def serialize_scheme(self, scheme: ResourceInstance):
+        scheme_id: str = str(scheme.pk)
+        return {
+            "resourceinstance_id": scheme_id,
+            "labels": [self.serialize_label(label) for label in scheme.labels],
+            "top_concepts": [
+                self.serialize_concept(concept_id)
+                for concept_id in self.top_concepts[scheme_id]
+            ],
+        }
+
+    def serialize_concept(self, conceptid: str):
+        return {
+            "resourceinstance_id": conceptid,
+            "labels": [self.serialize_label(label) for label in self.labels[conceptid]],
+            "narrower": [
+                self.serialize_concept(conceptid)
+                for conceptid in self.narrower_concepts[conceptid]
+            ],
+        }
+
+    def serialize_label(self, label: dict):
+        for language, inner_dict in label.items():
+            return {
+                "valuetype": "prefLabel",  # todo: get real
+                "language": language,
+                "value": inner_dict["value"],
+            }
+
+    def get(self, request):
+        self.top_concepts_map()
+        self.narrower_concepts_map()
+
+        self.schemes = ResourceInstance.objects.filter(
+            graph_id=SCHEMES_GRAPH_ID
+        ).annotate(labels=self.labels_subquery(SCHEME_LABEL_LOOKUP))
+
+        data = {
+            "schemes": [self.serialize_scheme(scheme) for scheme in self.schemes],
+        }
+        # Todo: filter by nodegroup permissions
+        return JSONResponse(data)