data modeling - add turtle owl import / export tools (#210)

a-s-g93 · web-flow · commit c13efa13b9d3 · 2025-11-03T10:35:59.000-06:00
* create and test

* remove rel prop conversion, update readme, update doc strings

* update docstrings
diff --git a/servers/mcp-neo4j-data-modeling/CHANGELOG.md b/servers/mcp-neo4j-data-modeling/CHANGELOG.md
@@ -5,6 +5,8 @@
 ### Changed
 
 ### Added
+* Add import and export methods to `DataModel` for turtle OWL strings
+* Add MCP tools for loading and exporting turtle OWL files
 
 ## v0.5.1
 
diff --git a/servers/mcp-neo4j-data-modeling/README.md b/servers/mcp-neo4j-data-modeling/README.md
@@ -125,6 +125,20 @@ These tools provide integration with **[Arrows](https://arrows.app/)** - a graph
      - `data_model` (DataModel): The data model to export
    - Returns: JSON string compatible with Arrows app
 
+- `load_from_owl_turtle`
+   - Load a data model from OWL Turtle format
+   - Input:
+     - `owl_turtle_str` (str): OWL Turtle string representation of an ontology
+   - Returns: DataModel object with nodes and relationships extracted from the ontology
+   - Note: **This conversion is lossy** - OWL Classes become Nodes, ObjectProperties become Relationships, and DatatypeProperties become Node properties.
+
+- `export_to_owl_turtle`
+   - Export a data model to OWL Turtle format
+   - Input:
+     - `data_model` (DataModel): The data model to export
+   - Returns: String representation of the data model in OWL Turtle format
+   - Note: **This conversion is lossy** - Relationship properties are not preserved since OWL does not support properties on ObjectProperties
+
 #### 📚 Example Data Model Tools
 
 These tools provide access to pre-built example data models for common use cases and domains.
diff --git a/servers/mcp-neo4j-data-modeling/pyproject.toml b/servers/mcp-neo4j-data-modeling/pyproject.toml
@@ -8,6 +8,7 @@ dependencies = [
     "fastmcp>=2.0.0",
     "pydantic>=2.10.1",
     "starlette>=0.47.0",
+    "rdflib>=7.0.0",
 ]
 
 
diff --git a/servers/mcp-neo4j-data-modeling/src/mcp_neo4j_data_modeling/data_model.py b/servers/mcp-neo4j-data-modeling/src/mcp_neo4j_data_modeling/data_model.py
@@ -3,6 +3,7 @@
 from typing import Any
 
 from pydantic import BaseModel, Field, ValidationInfo, field_validator
+from rdflib import Graph, Namespace, RDF, RDFS, OWL, XSD, Literal, URIRef
 
 NODE_COLOR_PALETTE = [
     ("#e3f2fd", "#1976d2"),  # Light Blue / Blue
@@ -551,6 +552,189 @@ def to_arrows_dict(self) -> dict[str, Any]:
     def to_arrows_json_str(self) -> str:
         "Convert the data model to an Arrows Data Model JSON string."
         return json.dumps(self.to_arrows_dict(), indent=2)
+    
+    def to_owl_turtle_str(self) -> str:
+        """
+        Convert the data model to an OWL Turtle string.
+
+        This process is lossy since OWL does not support properties on ObjectProperties.
+
+        This method creates an OWL ontology from the Neo4j data model:
+        - Node labels become OWL Classes
+        - Node properties become OWL DatatypeProperties with the node class as domain
+        - Relationship types become OWL ObjectProperties with start/end nodes as domain/range
+        - Relationship properties become OWL DatatypeProperties with the relationship as domain
+        """
+        # Create a new RDF graph
+        g = Graph()
+
+        # Define namespaces
+        # Use a generic namespace for the ontology
+        base_ns = Namespace("http://voc.neo4j.com/datamodel#")
+        g.bind("", base_ns)
+        g.bind("owl", OWL)
+        g.bind("rdfs", RDFS)
+        g.bind("xsd", XSD)
+
+        # Create the ontology declaration
+        ontology_uri = URIRef("http://voc.neo4j.com/datamodel")
+        g.add((ontology_uri, RDF.type, OWL.Ontology))
+
+        # Map Neo4j types to XSD types
+        type_mapping = {
+            "STRING": XSD.string,
+            "INTEGER": XSD.integer,
+            "FLOAT": XSD.float,
+            "BOOLEAN": XSD.boolean,
+            "DATE": XSD.date,
+            "DATETIME": XSD.dateTime,
+            "TIME": XSD.time,
+            "DURATION": XSD.duration,
+            "LONG": XSD.long,
+            "DOUBLE": XSD.double,
+        }
+
+        # Process nodes -> OWL Classes
+        for node in self.nodes:
+            class_uri = base_ns[node.label]
+            g.add((class_uri, RDF.type, OWL.Class))
+
+            # Add key property as a datatype property
+            if node.key_property:
+                prop_uri = base_ns[node.key_property.name]
+                g.add((prop_uri, RDF.type, OWL.DatatypeProperty))
+                g.add((prop_uri, RDFS.domain, class_uri))
+                xsd_type = type_mapping.get(node.key_property.type.upper(), XSD.string)
+                g.add((prop_uri, RDFS.range, xsd_type))
+
+            # Add other properties as datatype properties
+            for prop in node.properties:
+                prop_uri = base_ns[prop.name]
+                g.add((prop_uri, RDF.type, OWL.DatatypeProperty))
+                g.add((prop_uri, RDFS.domain, class_uri))
+                xsd_type = type_mapping.get(prop.type.upper(), XSD.string)
+                g.add((prop_uri, RDFS.range, xsd_type))
+
+        # Process relationships -> OWL ObjectProperties
+        for rel in self.relationships:
+            rel_uri = base_ns[rel.type]
+            g.add((rel_uri, RDF.type, OWL.ObjectProperty))
+            g.add((rel_uri, RDFS.domain, base_ns[rel.start_node_label]))
+            g.add((rel_uri, RDFS.range, base_ns[rel.end_node_label]))
+
+            # relationships don't have properties in the OWL format. 
+            # This means translation to OWL is lossy.
+
+        # Serialize to Turtle format
+        return g.serialize(format="turtle")
+
+    @classmethod
+    def from_owl_turtle_str(cls, owl_turtle_str: str) -> "DataModel":
+        """
+        Convert an OWL Turtle string to a Neo4j Data Model.
+
+        This process is lossy and some components of the ontology may be lost in the data model schema.
+
+        This method parses an OWL ontology and creates a Neo4j data model:
+        - OWL Classes become Node labels
+        - OWL DatatypeProperties with Class domains become Node properties
+        - OWL ObjectProperties become Relationships
+        - Property domains and ranges are used to infer Node labels and types
+        """
+        # Parse the Turtle string
+        g = Graph()
+        g.parse(data=owl_turtle_str, format="turtle")
+
+        # Map XSD types back to Neo4j types
+        xsd_to_neo4j = {
+            str(XSD.string): "STRING",
+            str(XSD.integer): "INTEGER",
+            str(XSD.float): "FLOAT",
+            str(XSD.boolean): "BOOLEAN",
+            str(XSD.date): "DATE",
+            str(XSD.dateTime): "DATETIME",
+            str(XSD.time): "TIME",
+            str(XSD.duration): "DURATION",
+            str(XSD.long): "LONG",
+            str(XSD.double): "DOUBLE",
+        }
+
+        # Extract OWL Classes -> Nodes
+        classes = set()
+        for s in g.subjects(RDF.type, OWL.Class):
+            classes.add(str(s).split("#")[-1].split("/")[-1])
+
+        # Extract DatatypeProperties
+        datatype_props = {}
+        for prop in g.subjects(RDF.type, OWL.DatatypeProperty):
+            prop_name = str(prop).split("#")[-1].split("/")[-1]
+            domains = list(g.objects(prop, RDFS.domain))
+            ranges = list(g.objects(prop, RDFS.range))
+
+            domain_name = str(domains[0]).split("#")[-1].split("/")[-1] if domains else None
+            range_type = xsd_to_neo4j.get(str(ranges[0]), "STRING") if ranges else "STRING"
+
+            if domain_name:
+                if domain_name not in datatype_props:
+                    datatype_props[domain_name] = []
+                datatype_props[domain_name].append({
+                    "name": prop_name,
+                    "type": range_type
+                })
+
+        # Extract ObjectProperties -> Relationships
+        object_props = []
+        for prop in g.subjects(RDF.type, OWL.ObjectProperty):
+            prop_name = str(prop).split("#")[-1].split("/")[-1]
+            domains = list(g.objects(prop, RDFS.domain))
+            ranges = list(g.objects(prop, RDFS.range))
+
+            if domains and ranges:
+                domain_name = str(domains[0]).split("#")[-1].split("/")[-1]
+                range_name = str(ranges[0]).split("#")[-1].split("/")[-1]
+
+                object_props.append({
+                    "type": prop_name,
+                    "start_node_label": domain_name,
+                    "end_node_label": range_name
+                })
+
+        # Create Nodes
+        nodes = []
+        for class_name in classes:
+            props_for_class = datatype_props.get(class_name, [])
+
+            # Use the first property as key property, or create a default one
+            if props_for_class:
+                key_prop = Property(
+                    name=props_for_class[0]["name"],
+                    type=props_for_class[0]["type"]
+                )
+                other_props = [
+                    Property(name=p["name"], type=p["type"])
+                    for p in props_for_class[1:]
+                ]
+            else:
+                # Create a default key property
+                key_prop = Property(name=f"{class_name.lower()}Id", type="STRING")
+                other_props = []
+
+            nodes.append(Node(
+                label=class_name,
+                key_property=key_prop,
+                properties=other_props
+            ))
+
+        # Create Relationships
+        relationships = []
+        for obj_prop in object_props:
+            relationships.append(Relationship(
+                type=obj_prop["type"],
+                start_node_label=obj_prop["start_node_label"],
+                end_node_label=obj_prop["end_node_label"]
+            ))
+
+        return cls(nodes=nodes, relationships=relationships) 
 
     def get_node_cypher_ingest_query_for_many_records(self, node_label: str) -> str:
         "Generate a Cypher query to ingest a list of Node records into a Neo4j database."
diff --git a/servers/mcp-neo4j-data-modeling/src/mcp_neo4j_data_modeling/server.py b/servers/mcp-neo4j-data-modeling/src/mcp_neo4j_data_modeling/server.py
@@ -328,6 +328,26 @@ def list_example_data_models() -> dict[str, Any]:
             "total_examples": len(examples),
             "usage": "Use the get_example_data_model tool with any of the example names above to get a specific data model",
         }
+    
+    @mcp.tool(name=namespace_prefix + "load_from_owl_turtle")
+    def load_from_owl_turtle(owl_turtle_str: str) -> DataModel:
+        """
+        Load a data model from an OWL Turtle string. 
+        This process is lossy and some components of the ontology may be lost in the data model schema.
+        Returns a DataModel object.
+        """
+        logger.info("Loading a data model from an OWL Turtle string.")
+        return DataModel.from_owl_turtle_str(owl_turtle_str)
+
+    @mcp.tool(name=namespace_prefix + "export_to_owl_turtle")
+    def export_to_owl_turtle(data_model: DataModel) -> str:
+        """
+        Export a data model to an OWL Turtle string. 
+        This process is lossy since OWL does not support properties on relationships.
+        Returns a string representation of the data model in OWL Turtle format.
+        """
+        logger.info("Exporting a data model to an OWL Turtle string.")
+        return data_model.to_owl_turtle_str()
 
     @mcp.prompt(title="Create New Data Model")
     def create_new_data_model(
diff --git a/servers/mcp-neo4j-data-modeling/tests/resources/blueplaques.ttl b/servers/mcp-neo4j-data-modeling/tests/resources/blueplaques.ttl
@@ -0,0 +1,113 @@
+@prefix : <http://voc.neo4j.com/blueplaques#> .
+@prefix owl: <http://www.w3.org/2002/07/owl#> .
+@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
+@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
+
+<http://voc.neo4j.com/blueplaques> a owl:Ontology .
+
+:COMPOSED a owl:ObjectProperty ;
+    rdfs:domain :Person ;
+    rdfs:range :MusicalComposition .
+
+:HONORED_BY a owl:ObjectProperty ;
+    rdfs:domain :Person ;
+    rdfs:range :Plaque .
+
+:LOCATED_AT a owl:ObjectProperty ;
+    rdfs:domain :Plaque ;
+    rdfs:range :Address .
+
+:addressId a owl:DatatypeProperty ;
+    rdfs:domain :Address ;
+    rdfs:range xsd:string .
+
+:area a owl:DatatypeProperty ;
+    rdfs:domain :Address ;
+    rdfs:range xsd:string .
+
+:birthYear a owl:DatatypeProperty ;
+    rdfs:domain :Person ;
+    rdfs:range xsd:integer .
+
+:borough a owl:DatatypeProperty ;
+    rdfs:domain :Address ;
+    rdfs:range xsd:string .
+
+:compositionId a owl:DatatypeProperty ;
+    rdfs:domain :MusicalComposition ;
+    rdfs:range xsd:string .
+
+:deathYear a owl:DatatypeProperty ;
+    rdfs:domain :Person ;
+    rdfs:range xsd:integer .
+
+:erectionYear a owl:DatatypeProperty ;
+    rdfs:domain :Plaque ;
+    rdfs:range xsd:integer .
+
+:genre a owl:DatatypeProperty ;
+    rdfs:domain :MusicalComposition ;
+    rdfs:range xsd:string .
+
+:inscription a owl:DatatypeProperty ;
+    rdfs:domain :Plaque ;
+    rdfs:range xsd:string .
+
+:material a owl:DatatypeProperty ;
+    rdfs:domain :Plaque ;
+    rdfs:range xsd:string .
+
+:name a owl:DatatypeProperty ;
+    rdfs:domain :Organization,
+        :Person ;
+    rdfs:range xsd:string .
+
+:nationality a owl:DatatypeProperty ;
+    rdfs:domain :Person ;
+    rdfs:range xsd:string .
+
+:organizationType a owl:DatatypeProperty ;
+    rdfs:domain :Organization ;
+    rdfs:range xsd:string .
+
+:personId a owl:DatatypeProperty ;
+    rdfs:domain :Person ;
+    rdfs:range xsd:string .
+
+:plaqueId a owl:DatatypeProperty ;
+    rdfs:domain :Plaque ;
+    rdfs:range xsd:string .
+
+:postcode a owl:DatatypeProperty ;
+    rdfs:domain :Address ;
+    rdfs:range xsd:string .
+
+:profession a owl:DatatypeProperty ;
+    rdfs:domain :Person ;
+    rdfs:range xsd:string .
+
+:professionCategory a owl:DatatypeProperty ;
+    rdfs:domain :Person ;
+    rdfs:range xsd:string .
+
+:streetAddress a owl:DatatypeProperty ;
+    rdfs:domain :Address ;
+    rdfs:range xsd:string .
+
+:title a owl:DatatypeProperty ;
+    rdfs:domain :MusicalComposition ;
+    rdfs:range xsd:string .
+
+:yearComposed a owl:DatatypeProperty ;
+    rdfs:domain :MusicalComposition ;
+    rdfs:range xsd:integer .
+
+:Organization a owl:Class .
+
+:MusicalComposition a owl:Class .
+
+:Address a owl:Class .
+
+:Plaque a owl:Class .
+
+:Person a owl:Class .
diff --git a/servers/mcp-neo4j-data-modeling/tests/unit/test_data_model.py b/servers/mcp-neo4j-data-modeling/tests/unit/test_data_model.py
diff --git a/servers/mcp-neo4j-data-modeling/uv.lock b/servers/mcp-neo4j-data-modeling/uv.lock

Original file line number	Diff line number	Diff line change
`@@ -8,6 +8,7 @@ dependencies = [`
`8`	`8`	`"fastmcp>=2.0.0",`
`9`	`9`	`"pydantic>=2.10.1",`
`10`	`10`	`"starlette>=0.47.0",`
	`11`	`+ "rdflib>=7.0.0",`
`11`	`12`	`]`
`12`	`13`
`13`	`14`