1 files changed, 66 insertions, 0 deletions
diff --git a/www/wiki/extensions/SemanticMediaWiki/src/SQLStore/Lookup/RedirectTargetLookup.php b/www/wiki/extensions/SemanticMediaWiki/src/SQLStore/Lookup/RedirectTargetLookup.php
new file mode 100644
index 00000000..b3aff967
--- /dev/null
+++ b/www/wiki/extensions/SemanticMediaWiki/src/SQLStore/Lookup/RedirectTargetLookup.php
@@ -0,0 +1,66 @@
+<?php
+
+namespace SMW\SQLStore\Lookup;
+
+use SMW\DIProperty;
+use SMW\DIWikiPage;
+use SMW\Store;
+use SMW\Utils\CircularReferenceGuard;
+
+/**
+ * @license GNU GPL v2+
+ * @since 2.5
+ *
+ * @author mwjames
+ */
+class RedirectTargetLookup {
+
+	/**
+	 * @var Store
+	 */
+	private $store;
+
+	/**
+	 * @var CircularReferenceGuard
+	 */
+	private $circularReferenceGuard;
+
+	/**
+	 * @since 2.5
+	 *
+	 * @param Store $store
+	 * @param CircularReferenceGuard $circularReferenceGuard
+	 */
+	public function __construct( Store $store, CircularReferenceGuard $circularReferenceGuard ) {
+		$this->store = $store;
+		$this->circularReferenceGuard = $circularReferenceGuard;
+	}
+
+	/**
+	 * @since 2.5
+	 *
+	 * @param $dataItem
+	 *
+	 * @return DataItem
+	 */
+	public function findRedirectTarget( $dataItem ) {
+
+		if ( !$dataItem instanceof DIWikiPage && !$dataItem instanceof DIProperty ) {
+			return $dataItem;
+		}
+
+		$hash = $dataItem->getSerialization();
+
+		// Guard against a dataItem that points to itself
+		$this->circularReferenceGuard->mark( $hash );
+
+		if ( !$this->circularReferenceGuard->isCircular( $hash ) ) {
+			$dataItem = $this->store->getRedirectTarget( $dataItem );
+		}
+
+		$this->circularReferenceGuard->unmark( $hash );
+
+		return $dataItem;
+	}
+
+}