Introduce https://enola.dev/labelProperty

docs/concepts/metadata.md

@@ -41,6 +41,9 @@ This is read from a number of "typical" properties; in order of priority:
 
 If the thing itself doesn't have any of these, it will check if its [RDFS range](../models/www.w3.org/2000/01/rdf-schema/range.md) has any.
 
+Alternatively, the (RDFS) `Class` of a Thing's (RDF) `type` can specify an [https://enola.dev/labelProperty](../models/enola.dev/labelProperty.md)
+to specify the IRI of a "custom" property to use a label, if present; see `test/metadata-label-property.ttl` for an example illustrating how to use this.
+
 This is always available; if a Thing has none of the above, then it will fallback to the CURIE, or else just the last part of its IRI.
 
 ## Description

java/dev/enola/thing/BUILD

@@ -116,6 +116,7 @@ junit_tests(
  ":thing_java",
  ":thing_java_proto",
  "//java/dev/enola/common/context",
+ "//java/dev/enola/common/context/testlib",
  "//java/dev/enola/common/convert",
  "//java/dev/enola/common/function",
  "//java/dev/enola/common/io",

java/dev/enola/thing/KIRI.java

@@ -66,6 +66,7 @@ public static final class E {
 
  public static final String IRI_TEMPLATE_PROPERTY = NS + "iriTemplate";
  public static final String IRI_TEMPLATE_DATATYPE = NS + "IRITemplate";
+ public static final String LABEL_PROPERTY = NS + "labelProperty";
  }
 
  /** Schema.org Properties. */

java/dev/enola/thing/metadata/ThingMetadataProvider.java

@@ -37,7 +37,8 @@
 
 /**
  * {@link MetadataProvider} implementation based on looking at {@link Things}s obtained via {@link
- * ThingProvider}.
+ * ThingProvider}; see also related <a href="https://docs.enola.dev/concepts/metadata/>end-user
+ * documentation</a>.
  *
  * <p>Logs errors, but does not propagate exceptions from the <tt>ThingProvider</tt>, because we do
  * not want to fail operations "just" because Metadata could not be obtained; all the methods have
@@ -101,10 +102,13 @@ public Metadata get(@Nullable Thing thing, String fallbackIRI) {
  * as-is.
  */
  private String getLabel(@Nullable Thing thing, String curie, String fallbackIRI) {
- var label = getLabel_(thing);
+ var label = getAlternative(thing, KIRI.RDF.TYPE, type -> getLabelViaProperty(thing, type));
  if (label != null) return label;
 
- label = getAlternative(thing, KIRI.RDFS.RANGE, thingX -> getLabel_(thingX));
+ label = getLabel_(thing);
+ if (label != null) return label;
+
+ label = getAlternative(thing, KIRI.RDFS.RANGE, range -> getLabel_(range));
  if (label != null) return label;
 
  if (!curie.equals(fallbackIRI)) return curie;
@@ -123,6 +127,13 @@ private String getLabel(@Nullable Thing thing, String curie, String fallbackIRI)
  }
  }
 
+ private @Nullable String getLabelViaProperty(@Nullable Thing thing, Thing type) {
+ if (thing == null) return null;
+ var typesLabelProperty = type.getString(KIRI.E.LABEL_PROPERTY);
+ if (typesLabelProperty == null) return null;
+ return thing.getString(typesLabelProperty);
+ }
+
  private @Nullable String getLabel_(@Nullable Thing thing) {
  var label = getString(thing, KIRI.RDFS.LABEL);
  if (label != null) return label;
@@ -184,18 +195,18 @@ private String getImageHTML(Thing thing) {
  var emoji = getString(thing, KIRI.E.EMOJI);
  if (emoji != null) return emoji;
 
- emoji = getAlternative(thing, KIRI.RDFS.RANGE, thingX -> getEmoji_(thingX));
+ emoji = getAlternative(thing, KIRI.RDFS.RANGE, range -> getEmoji_(range));
  if (emoji != null) return emoji;
 
- emoji = getAlternative(thing, KIRI.RDF.TYPE, thingX -> getEmoji_(thingX));
+ emoji = getAlternative(thing, KIRI.RDF.TYPE, type -> getEmoji_(type));
  return emoji;
  }
 
  private @Nullable String getImageURL_(Thing thing) {
- var imageURL = getAlternative(thing, KIRI.RDFS.RANGE, thingX -> getImageURL__(thingX));
+ var imageURL = getAlternative(thing, KIRI.RDFS.RANGE, range -> getImageURL__(range));
  if (imageURL != null) return imageURL;
 
- imageURL = getAlternative(thing, KIRI.RDF.TYPE, thingX -> getImageURL__(thingX));
+ imageURL = getAlternative(thing, KIRI.RDF.TYPE, type -> getImageURL__(type));
  return imageURL;
  }
 

java/dev/enola/thing/metadata/ThingMetadataProviderTest.java

@@ -19,18 +19,25 @@
 
 import static com.google.common.truth.Truth.assertThat;
 
+import dev.enola.common.context.testlib.EnolaTestTLCRules;
+import dev.enola.common.context.testlib.TestTLCRule;
 import dev.enola.common.io.iri.namespace.NamespaceConverter;
 import dev.enola.common.io.iri.namespace.NamespaceConverterIdentity;
 import dev.enola.thing.KIRI;
 import dev.enola.thing.Thing;
 import dev.enola.thing.impl.ImmutableThing;
+import dev.enola.thing.io.Loader;
+import dev.enola.thing.repo.ThingMemoryRepositoryRW;
 import dev.enola.thing.repo.ThingProvider;
 
 import org.jspecify.annotations.Nullable;
+import org.junit.Rule;
 import org.junit.Test;
 
 public class ThingMetadataProviderTest {
 
+ @Rule public TestTLCRule rlcRule = EnolaTestTLCRules.BASIC;
+
  private static final NamespaceConverter NONS = new NamespaceConverterIdentity();
 
  private static final ThingProvider NO_THING_PROVIDER = iri -> null;
@@ -80,6 +87,16 @@ public void label() {
  .isEqualTo(THING_LABEL);
  }
 
+ @Test
+ public void labelViaAlternativeLabelProperty() {
+ var uri = java.net.URI.create("classpath:/metadata-label-property.ttl");
+ var repo = new ThingMemoryRepositoryRW();
+ var things = new Loader().load(uri, repo);
+ var metadataProvider = new ThingMetadataProvider(repo, NONS);
+ var metadata = metadataProvider.get("https://example.org/test-metadata-label-property");
+ assertThat(metadata.label()).isEqualTo("LABEL");
+ }
+
  @Test
  public void description() {
  assertThat(new ThingMetadataProvider(test, NONS).get(THING_IRI).descriptionHTML())

models/enola.dev/enola.ttl

@@ -85,6 +85,12 @@ enola:emoji a rdf:Property;
  schema:description "Emoji 😃 of a Thing, from Unicode or <a href='https://www.nerdfonts.com'>Nerdfonts</a>.";
  enola:emoji "😃".
 
+enola:labelProperty a rdf:Property;
+ schema:name "Label Property";
+ rdfs:domain rdfs:Class;
+ rdfs:range xsd:anyURI;
+ schema:description "The IRI of a property to be used as Label for Things of this Class; see https://docs.enola.dev/concepts/metadata/".
+
 enola:parent a rdf:Property;
  rdfs:range schema:Thing;
  rdfs:comment "A 'hierarchical' parent. This is typically subclassed - and thus there could be several different kinds of parents. Similar to https://schema.org/isPartOf; but that's specific to CreativeWork, while this is not.".

test/metadata-label-property.ttl

@@ -19,7 +19,7 @@
 @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>.
 
 example:test-metadata-label-property-class a rdfs:Class;
- enola:label-property enola:altlab.
+ enola:labelProperty enola:altlab.
 
 example:test-metadata-label-property a example:test-metadata-label-property-class;
  enola:altlab "LABEL".