From e1e0bf5c2d634c4b2e5350614625996e843e2e9a Mon Sep 17 00:00:00 2001
From: Federico Igne <federico.igne@cs.ox.ac.uk>
Date: Tue, 11 Aug 2020 12:40:35 +0100
Subject: Add code to communicate with a local RDFox instance

---
 src/main/scala/rsacomb/RDFox.scala       | 24 +++++++++++++++++++
 src/main/scala/rsacomb/RSAOntology.scala | 40 +++++++++++++++++++++++++++++---
 2 files changed, 61 insertions(+), 3 deletions(-)
 create mode 100644 src/main/scala/rsacomb/RDFox.scala

(limited to 'src')

diff --git a/src/main/scala/rsacomb/RDFox.scala b/src/main/scala/rsacomb/RDFox.scala
new file mode 100644
index 0000000..a263091
--- /dev/null
+++ b/src/main/scala/rsacomb/RDFox.scala
@@ -0,0 +1,24 @@
+package rsacomb
+
+/* Java imports */
+import java.util.HashMap
+import tech.oxfordsemantic.jrdfox.client.{ConnectionFactory,ServerConnection,DataStoreConnection}
+
+object RDFox {
+
+    def openConnection(dataStore: String): (ServerConnection,DataStoreConnection) = {
+      val serverUrl = "rdfox:local"
+      val role = ""
+      val password = ""
+      val server = ConnectionFactory.newServerConnection(serverUrl, role, password)
+      server.createDataStore(dataStore,"seq",new HashMap())
+      val data = server.newDataStoreConnection(dataStore)
+      (server,data)
+    }
+
+    def closeConnection(server: ServerConnection, data: DataStoreConnection): Unit = {
+      server.close();
+      data.close();
+    }
+
+} // object RDFox
\ No newline at end of file
diff --git a/src/main/scala/rsacomb/RSAOntology.scala b/src/main/scala/rsacomb/RSAOntology.scala
index ebe1591..92be118 100644
--- a/src/main/scala/rsacomb/RSAOntology.scala
+++ b/src/main/scala/rsacomb/RSAOntology.scala
@@ -1,6 +1,7 @@
 package rsacomb
 
 /* Java imports */
+import java.util.HashMap
 import java.util.stream.{Collectors,Stream}
 
 import org.semanticweb.owlapi.model.OWLOntology
@@ -8,13 +9,17 @@ import org.semanticweb.owlapi.model.OWLObjectPropertyExpression
 import org.semanticweb.owlapi.model.parameters.Imports
 import org.semanticweb.owlapi.reasoner.structural.StructuralReasonerFactory
 
+import tech.oxfordsemantic.jrdfox.Prefixes
 import tech.oxfordsemantic.jrdfox.logic.Variable
+import tech.oxfordsemantic.jrdfox.client.UpdateType
+
 
 /* Scala imports */
 import scala.collection.JavaConverters._
 
 /* Debug only */
 import org.semanticweb.owlapi.dlsyntax.renderer.DLSyntaxObjectRenderer
+import java.io.OutputStream
 
 /* Wrapper trait for the implicit class `RSAOntology`.
  */
@@ -48,12 +53,41 @@ trait RSAOntology {
       tbox.foreach(x => println(renderer.render(x)))
 
       /* Ontology convertion into LP rules */
-      println("\nLP rules:")
-      for {
+      val datalog = for {
         axiom <- tbox
         visitor = new RDFoxAxiomConverter(Variable.create("x"), SkolemStrategy.ConstantRSA(axiom.toString), unsafe)
         rule  <- axiom.accept(visitor)
-      } yield println(rule)
+      } yield rule
+
+      val prefixes = new Prefixes()
+      prefixes.declarePrefix(":", "http://example.com/rsa_example.owl#")
+
+      // Open connection with RDFox
+      val (server,data) = RDFox.openConnection("RSACheck")
+      // Add Data (hardcoded for now)
+      data.importData(UpdateType.ADDITION, prefixes,":a a :A .")
+      /* Add Datalog rules
+       *
+       * NOTE:
+       * - using the `addRules(...)` method in `DataStoreConnection` is not working as expected, complaining
+       *   about missing TupleTable entries;
+       * - weirdly enough, the same error is returned when trying to pass the rules to the `importData` method,
+       *   simply turning them into strings. It seems like the `toString` implementation of `Rule` uses parenthesis
+       *   for predicate arguments (e.g., `<predicate>(?X,?Y)`) while the specification for the proprietary RDFox
+       *   syntax uses squared brackets (e.g., `<preditate>[?X,?Y]`).
+       */
+      data.importData(
+        UpdateType.ADDITION,
+        prefixes,
+        datalog.foldLeft("")((str,rule) => str ++ "\n" ++ rule.toString().replace("(", "[").replace(")","]"))
+      )
+
+      // Retrieve all instances of PE
+      println("\nQuery results:")
+      data.evaluateQuery(prefixes,"SELECT ?X ?Y WHERE { ?X <internal:PE> ?Y }", new HashMap[String,String](), System.out, "text/csv");
+
+      // Close connection to RDFox
+      RDFox.closeConnection(server,data)
 
       /* DEBUG */
       true
-- 
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