Return values by default, use _literal suffix to access full RDFLiter…

…al objects

README.md

@@ -105,10 +105,30 @@ goblin.enemyOf.println('Enemies of the Green Goblin: ');
 If there are predicates with the same local name but different namespace URIs in the graph formed by all the loaded documents in a model, a warning will be issued.
 In this case, you should be using a prefix to avoid the ambiguity.
 
+### Values of predicates
+
+The values in `resource.p` will be either other resources, or the values of the associated literals (without filtering by language tags).
+
 It is possible to mention a language suffix, to limit the results to literals with that language.
 For instance:
 
 ```
 var spider = Model.getElementById('http://example.org/#spiderman');
 spider.`name@ru`.println('Name of Spiderman in Russian: ');
 ```
+
+### Accessing literal objects
+
+If you would like to access the `RDFLiteral` objects rather than just their values, use a `_literal` suffix as part of the local name (before any language tags).
+For instance, we could change the above example to:
+
+```
+var spider = Model.getElementById('http://example.org/#spiderman');
+spider.`name_literal@ru`.println('Name literal of Spiderman in Russian: ');
+```
+
+`RDFLiteral` objects have several properties:
+
+* `value`: the raw value of the literal (usually a String, but it can be different for typed literals - see [Apache Jena typed literals](https://jena.apache.org/documentation/notes/typed-literals.html)).
+* `language`: the language tag for the literal (if any).
+* `datatypeURI`: the datatype URI for the literal.

bundles/org.eclipse.epsilon.emc.rdf/src/org/eclipse/epsilon/emc/rdf/RDFQualifiedName.java

@@ -58,4 +58,15 @@ public static RDFQualifiedName from(String property, Function<String, String> pr
 
 		return new RDFQualifiedName(prefix, nsURI, property, languageTag);
 	}
+
+	public RDFQualifiedName withLocalName(String newLocalName) {
+		return new RDFQualifiedName(prefix, namespaceURI, newLocalName, languageTag);
+	}
+
+	@Override
+	public String toString() {
+		return "RDFQualifiedName [prefix=" + prefix + ", namespaceURI=" + namespaceURI + ", localName=" + localName
+				+ ", languageTag=" + languageTag + "]";
+	}
+
 }

bundles/org.eclipse.epsilon.emc.rdf/src/org/eclipse/epsilon/emc/rdf/RDFResource.java

@@ -33,6 +33,12 @@
 
 public class RDFResource extends RDFModelElement {
 
+	protected static final String LITERAL_SUFFIX = "_literal";
+
+	enum LiteralMode {
+		RAW, VALUES_ONLY
+	}
+
 	private Resource resource;
 
 	public RDFResource(Resource resource, RDFModel rdfModel) {
@@ -47,6 +53,17 @@ public Resource getResource() {
 	public Collection<Object> getProperty(String property, IEolContext context) {
 		final RDFQualifiedName pName = RDFQualifiedName.from(property, this.owningModel::getNamespaceURI);
 
+		Collection<Object> value = getProperty(pName, context, LiteralMode.VALUES_ONLY);
+		if (value.isEmpty() && pName.localName.endsWith(LITERAL_SUFFIX)) {
+			final String localNameWithoutSuffix = pName.localName.substring(0, pName.localName.length() - LITERAL_SUFFIX.length());
+			RDFQualifiedName withoutLiteral = pName.withLocalName(localNameWithoutSuffix);
+			return getProperty(withoutLiteral, context, LiteralMode.RAW);
+		}
+
+		return value;
+	}
+
+	public Collection<Object> getProperty(RDFQualifiedName pName, IEolContext context, LiteralMode literalMode) {
 		// Filter statements by prefix and local name
 		ExtendedIterator<Statement> itStatements = null;
 		if (pName.prefix == null) {
@@ -74,14 +91,15 @@ public Collection<Object> getProperty(String property, IEolContext context) {
 			ListMultimap<String, Object> values = MultimapBuilder.hashKeys().arrayListValues().build();
 			while (itStatements.hasNext()) {
 				Statement stmt = itStatements.next();
-				values.put(stmt.getPredicate().getURI(), convertToModelObject(stmt.getObject()));
+				values.put(stmt.getPredicate().getURI(),
+						convertToModelObject(stmt.getObject(), literalMode));
 			}
 
 			final Set<String> distinctKeys = values.keySet();
 			if (distinctKeys.size() > 1) {
 				context.getWarningStream().println(String.format(
 					"Ambiguous access to property '%s': multiple prefixes found (%s)",
-					property,
+					pName,
 					String.join(", ", distinctKeys)
 				));
 			}
@@ -92,7 +110,7 @@ public Collection<Object> getProperty(String property, IEolContext context) {
 			final List<Object> values = new ArrayList<>();
 			while (itStatements.hasNext()) {
 				Statement stmt = itStatements.next();
-				values.add(convertToModelObject(stmt.getObject()));
+				values.add(convertToModelObject(stmt.getObject(), literalMode));
 			}
 			return values;
 		}
@@ -111,9 +129,14 @@ public String getUri() {
 		return resource.getURI();
 	}
 
-	protected RDFModelElement convertToModelObject(RDFNode node) {
+	protected Object convertToModelObject(RDFNode node, LiteralMode lMode) {
 		if (node instanceof Literal) {
-			return new RDFLiteral((Literal) node, this.owningModel);
+			switch (lMode) {
+			case RAW:
+				return new RDFLiteral((Literal) node, this.owningModel);
+			case VALUES_ONLY:
+				return ((Literal) node).getValue();
+			}
 		} else if (node instanceof Resource) {
 			return new RDFResource((Resource) node, this.owningModel);
 		}

tests/org.eclipse.epsilon.emc.rdf.tests/src/org/eclipse/epsilon/emc/rdf/RDFModelTest.java

@@ -76,40 +76,39 @@ public void listAll() throws EolModelLoadingException {
 	public void getNamesWithoutPrefix() throws Exception {
 		Set<String> names = new HashSet<>();
 		for (RDFModelElement o : model.allContents()) {
-			for (RDFLiteral l : (Collection<RDFLiteral>) pGetter.invoke(o, "name", context)) {
-				names.add((String) pGetter.invoke(l, "value", context));
-			}
+			names.addAll((Collection<String>) pGetter.invoke(o, "name", context));
 		}
 		assertEquals(ALL_NAMES, names);
 	}
 
 	@Test
 	public void getNamesWithPrefix() throws Exception {
+		RDFResource res = (RDFResource) model.getElementById(SPIDERMAN_URI);
+		Set<String> names = new HashSet<>((Collection<String>) pGetter.invoke(res, "foaf:name", context));
+		assertEquals(SPIDERMAN_NAMES, names);
+	}
+
+	@Test
+	public void getNameLiteralsWithPrefix() throws Exception {
 		RDFResource res = (RDFResource) model.getElementById(SPIDERMAN_URI);
 		Set<String> names = new HashSet<>();
-		for (RDFLiteral l : (Collection<RDFLiteral>) pGetter.invoke(res, "foaf:name", context)) {
-			names.add((String) pGetter.invoke(l, "value", context));
+		for (RDFLiteral l : (Collection<RDFLiteral>) pGetter.invoke(res, "foaf:name_literal", context)) {
+			names.add((String) l.getValue());
 		}
 		assertEquals(SPIDERMAN_NAMES, names);
 	}
 
 	@Test
 	public void getNamesWithoutPrefixWithLanguageTag() throws Exception {
 		RDFResource res = (RDFResource) model.getElementById(SPIDERMAN_URI);
-		Set<String> names = new HashSet<>();
-		for (RDFLiteral l : (Collection<RDFLiteral>) pGetter.invoke(res, "name@ru", context)) {
-			names.add((String) pGetter.invoke(l, "value", context));
-		}
+		Set<String> names = new HashSet<>((Collection<String>) pGetter.invoke(res, "name@ru", context));
 		assertEquals(Collections.singleton(SPIDERMAN_NAME_RU), names);
 	}
 
 	@Test
 	public void getNamesWithPrefixAndLanguageTag() throws Exception {
 		RDFResource res = (RDFResource) model.getElementById(SPIDERMAN_URI);
-		Set<String> names = new HashSet<>();
-		for (RDFLiteral l : (Collection<RDFLiteral>) pGetter.invoke(res, "foaf:name@ru", context)) {
-			names.add((String) pGetter.invoke(l, "value", context));
-		}
+		Set<String> names = new HashSet<>((Collection<String>) pGetter.invoke(res, "foaf:name@ru", context));
 		assertEquals(Collections.singleton(SPIDERMAN_NAME_RU), names);
 	}