1 files changed, 62 insertions, 0 deletions
diff --git a/www/wiki/extensions/SemanticMediaWiki/src/Exporter/ResourceBuilders/ExternalIdentifierPropertyValueResourceBuilder.php b/www/wiki/extensions/SemanticMediaWiki/src/Exporter/ResourceBuilders/ExternalIdentifierPropertyValueResourceBuilder.php
new file mode 100644
index 00000000..a27f766f
--- /dev/null
+++ b/www/wiki/extensions/SemanticMediaWiki/src/Exporter/ResourceBuilders/ExternalIdentifierPropertyValueResourceBuilder.php
@@ -0,0 +1,62 @@
+<?php
+
+namespace SMW\Exporter\ResourceBuilders;
+
+use SMW\DataValueFactory;
+use SMW\DIProperty;
+use SMWDataItem as DataItem;
+use SMWDIUri as DIUri;
+use SMWExpData as ExpData;
+
+/**
+ * @private
+ *
+ * @license GNU GPL v2+
+ * @since 2.5
+ *
+ * @author mwjames
+ */
+class ExternalIdentifierPropertyValueResourceBuilder extends PropertyValueResourceBuilder {
+
+	/**
+	 * @since 2.5
+	 *
+	 * {@inheritDoc}
+	 */
+	public function isResourceBuilderFor( DIProperty $property ) {
+		return $property->findPropertyTypeID() === '_eid';
+	}
+
+	/**
+	 * Instead of representing an external identifier as "owl:sameAs", the weaker
+	 * declarative axiom "skos:exactMatch" has been chosen to avoid potential
+	 * issues with undesirable entailments.
+	 *
+	 * "skos:exactMatch" has been defined as "... indicating a high degree of
+	 * confidence that the concepts can be used interchangeably across a wide
+	 * range of information retrieval applications ..."
+	 *
+	 * @since 2.5
+	 *
+	 * {@inheritDoc}
+	 */
+	public function addResourceValue( ExpData $expData, DIProperty $property, DataItem $dataItem ) {
+
+		parent::addResourceValue( $expData, $property, $dataItem );
+
+		$dataValue = DataValueFactory::getInstance()->newDataValueByItem(
+			$dataItem,
+			$property
+		);
+
+		$uri = $dataValue->getUri();
+
+		if ( $uri instanceof DIUri ) {
+			$expData->addPropertyObjectValue(
+				$this->exporter->getSpecialNsResource( 'skos', 'exactMatch' ),
+				$this->exporter->getDataItemExpElement( $uri )
+			);
+		}
+	}
+
+}