Description
Opening Ontology → Explorer → Graph shows classes but no relationship (object-property) edges, even for an ontology whose object properties are known to be stored. The status line reads N nodes · 0 edges. Selecting a node lists its relationships in the side panel, but nothing is ever drawn between class nodes. The Induction proposal page for the same ontology does draw them, so users conclude the accepted ontology lost its relationships.
Environment
- Commit ID: Observed on
42b5c6b (tag v0.2.2). _sample_overview() and GraphSearch.tsx are unchanged on e265573 (tag v0.3.1 = main).
- Environment: ap-northeast-1 deployment
Step to reproduce
Two independent paths reproduce it; the second one removes scanning and the LLM from the picture entirely.
A. Induced ontology
B. Uploaded ontology with explicit object properties (deterministic)
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix ex: <https://example.com/u1-test#> .
<https://example.com/u1-test> a owl:Ontology .
ex:Customer a owl:Class . ex:Order a owl:Class . ex:Claim a owl:Class .
ex:placedBy a owl:ObjectProperty ; rdfs:domain ex:Order ; rdfs:range ex:Customer .
ex:raisedBy a owl:ObjectProperty ; rdfs:domain ex:Claim ; rdfs:range ex:Customer .
With two ontologies in the namespace the status line reads 6 nodes · 0 edges (3 seed roots per ontology).
A root cause
Two halves, one on each side.
-
Server. The Graph view's initial data comes from GET …/ontology-overview?sample=true, served by _sample_overview() in packages/ontology-engine/src/coa_ontology/stores/neptune_db_graph.py (L1429). It returns classes only and hard-codes
"object_properties": [],
"datatype_properties": [],
(L1500-1501). The docstring says: "Properties are omitted — the Graph view fetches a node's relationships on selection."
-
Client. buildGraphData() in packages/web-app/src/pages/ontology/GraphSearch.tsx (L141-190) only draws an edge when both endpoints are visible vertices. Relationships are modelled as object-property vertices sitting between two classes, so a class→class relationship can only appear on the canvas if the property vertex itself is in the visible set. The seed never contains property vertices, and the on-selection fetch only feeds the side panel — it does not add the property vertex to visibleUris. Double-click expands sub-classes only (the hint text says so). So from the seed view there is no user action that ever brings a relationship onto the canvas.
Net effect: the Graph view is a subClassOf taxonomy view labelled as an ontology graph, with a legend that promises "Relationship" (orange) nodes that can only appear via the search path.
Fix (proposal)
- In
_sample_overview(), include object properties whose domain and range are both inside the sampled class set (bounded by construction), and/or
- On selection / expand, add the fetched
object-property vertices (and their far-end class, within budget) to visibleUris so buildGraphData() can draw them, and
- Change the hint text to state what expand does and does not load.
Context
Reported by a customer evaluating v0.2.2 on ap-northeast-1 with a Snowflake source ("edges are not shown in Explorer's initial graph, but are shown in Induction"). Related: #196 (3-node cap in the same _sample_overview()), #197 (same evaluation). The proposal page (ProposalDetail.tsx) draws edges from the proposal JSON directly, which is why they are visible there.
Additional Information / References
Uploaded test ontology with 2 object properties, Graph view shows no edges (6 nodes = 3 seed roots × 2 ontologies):
Description
Opening Ontology → Explorer → Graph shows classes but no relationship (object-property) edges, even for an ontology whose object properties are known to be stored. The status line reads
N nodes · 0 edges. Selecting a node lists its relationships in the side panel, but nothing is ever drawn between class nodes. The Induction proposal page for the same ontology does draw them, so users conclude the accepted ontology lost its relationships.Environment
42b5c6b(tagv0.2.2)._sample_overview()andGraphSearch.tsxare unchanged one265573(tagv0.3.1=main).Step to reproduce
Two independent paths reproduce it; the second one removes scanning and the LLM from the picture entirely.
A. Induced ontology
3 nodes · 0 edges(see [Bug]: Graph view fetches the full class set but returns a silent subset (UI) #196 for the 3-node cap on the same code path)B. Uploaded ontology with explicit object properties (deterministic)
Classes 3 / Properties 4— the twoowl:ObjectPropertyare stored… · 0 edgesRelationships (…), but no edge is drawn on the canvasWith two ontologies in the namespace the status line reads
6 nodes · 0 edges(3 seed roots per ontology).A root cause
Two halves, one on each side.
Server. The Graph view's initial data comes from
GET …/ontology-overview?sample=true, served by_sample_overview()inpackages/ontology-engine/src/coa_ontology/stores/neptune_db_graph.py(L1429). It returns classes only and hard-codes(L1500-1501). The docstring says: "Properties are omitted — the Graph view fetches a node's relationships on selection."
Client.
buildGraphData()inpackages/web-app/src/pages/ontology/GraphSearch.tsx(L141-190) only draws an edge when both endpoints are visible vertices. Relationships are modelled asobject-propertyvertices sitting between two classes, so a class→class relationship can only appear on the canvas if the property vertex itself is in the visible set. The seed never contains property vertices, and the on-selection fetch only feeds the side panel — it does not add the property vertex tovisibleUris. Double-click expands sub-classes only (the hint text says so). So from the seed view there is no user action that ever brings a relationship onto the canvas.Net effect: the Graph view is a
subClassOftaxonomy view labelled as an ontology graph, with a legend that promises "Relationship" (orange) nodes that can only appear via the search path.Fix (proposal)
_sample_overview(), include object properties whose domain and range are both inside the sampled class set (bounded by construction), and/orobject-propertyvertices (and their far-end class, within budget) tovisibleUrissobuildGraphData()can draw them, andContext
Reported by a customer evaluating v0.2.2 on ap-northeast-1 with a Snowflake source ("edges are not shown in Explorer's initial graph, but are shown in Induction"). Related: #196 (3-node cap in the same
_sample_overview()), #197 (same evaluation). The proposal page (ProposalDetail.tsx) draws edges from the proposal JSON directly, which is why they are visible there.Additional Information / References
Uploaded test ontology with 2 object properties, Graph view shows no edges (6 nodes = 3 seed roots × 2 ontologies):