1 files changed, 138 insertions, 0 deletions
diff --git a/www/wiki/extensions/SemanticMediaWiki/src/ChangePropListener.php b/www/wiki/extensions/SemanticMediaWiki/src/ChangePropListener.php
new file mode 100644
index 00000000..b41a0ddc
--- /dev/null
+++ b/www/wiki/extensions/SemanticMediaWiki/src/ChangePropListener.php
@@ -0,0 +1,138 @@
+<?php
+
+namespace SMW;
+
+use Closure;
+use SMW\Exception\PropertyLabelNotResolvedException;
+
+/**
+ * @license GNU GPL v2+
+ * @since 3.0
+ *
+ * @author mwjames
+ */
+class ChangePropListener {
+
+	/**
+	 * @var []
+	 */
+	private static $listenerCallbacks = [];
+
+	/**
+	 * @var []
+	 */
+	private static $deferrableCallbacks = [];
+
+	/**
+	 * @since 3.0
+	 */
+	public static function clearListeners() {
+		self::$listenerCallbacks = [];
+		self::$deferrableCallbacks = [];
+	}
+
+	/**
+	 * @since 3.0
+	 *
+	 * @param string $key
+	 * @param Closure $callback
+	 */
+	public function addListenerCallback( $key, Closure $callback ) {
+
+		if ( $key === '' ) {
+			return;
+		}
+
+		if ( !isset( self::$listenerCallbacks[$key] ) ) {
+			self::$listenerCallbacks[$key] = [];
+		}
+
+		self::$listenerCallbacks[$key][] = $callback;
+	}
+
+	/**
+	 * Finalize event inception points by matching the key to a property
+	 * equivalent representation.
+	 *
+	 * @since 3.0
+	 *
+	 * @param Store $store
+	 */
+	public function loadListeners( Store $store ) {
+
+		foreach ( self::$listenerCallbacks as $key => $value ) {
+
+			try {
+				$property = DIProperty::newFromUserLabel( $key );
+			} catch ( PropertyLabelNotResolvedException $e ) {
+				continue;
+			}
+
+			$pid = $store->getObjectIds()->getSMWPropertyID(
+				$property
+			);
+
+			self::$listenerCallbacks[$pid] = $value;
+			unset( self::$listenerCallbacks[$key] );
+		}
+	}
+
+	/**
+	 * @since 3.0
+	 *
+	 * @param integer $pid
+	 * @param array $record
+	 */
+	public static function record( $pid, array $record ) {
+
+		if ( !isset( self::$listenerCallbacks[$pid] ) ) {
+			return;
+		}
+
+		if ( !isset( self::$deferrableCallbacks[$pid] ) ) {
+			self::$deferrableCallbacks[$pid] = [];
+		}
+
+		// Copy callbacks to the deferred list to isolate the execution
+		// from the event point
+		foreach ( self::$listenerCallbacks[$pid] as $callback ) {
+			self::$deferrableCallbacks[$pid][] = [ $callback, $record ];
+		}
+	}
+
+	/**
+	 * @since 3.0
+	 */
+	public function callListeners() {
+
+		if ( self::$deferrableCallbacks === [] ) {
+			return;
+		}
+
+		$deferrableCallbacks = self::$deferrableCallbacks;
+
+		$callback = function() use( $deferrableCallbacks ) {
+			foreach ( $deferrableCallbacks as $pid => $records ) {
+				foreach ( $records as $rec ) {
+					call_user_func_array( $rec[0], [ $rec[1] ] );
+				}
+			}
+		};
+
+		$deferredTransactionalUpdate = ApplicationFactory::getInstance()->newDeferredTransactionalCallableUpdate(
+			$callback
+		);
+
+		$deferredTransactionalUpdate->setOrigin(
+			[
+				'ChangePropListener::callListeners'
+			]
+		);
+
+		$deferredTransactionalUpdate->commitWithTransactionTicket();
+		$deferredTransactionalUpdate->pushUpdate();
+
+		self::$deferrableCallbacks = [];
+	}
+
+}