2 files changed, 77 insertions, 1 deletions
diff --git a/engine/lib/river.php b/engine/lib/river.php
index 5d2490596..d1b55ad11 100644
--- a/engine/lib/river.php
+++ b/engine/lib/river.php
@@ -1,7 +1,7 @@
 <?php
 	/**
 	 * Elgg river.
-	 * Functions for listening for and generating the river.
+	 * Functions for listening for and generating the river out of the system log.
 	 * 
 	 * @package Elgg
 	 * @subpackage Core
@@ -10,4 +10,6 @@
 	 * @copyright Curverider Ltd 2008
 	 * @link http://elgg.org/
 	 */
+
+	// event listener
 ?>
 \ No newline at end of file
diff --git a/engine/lib/system_log.php b/engine/lib/system_log.php
new file mode 100644
index 000000000..8c820cbee
--- /dev/null
+++ b/engine/lib/system_log.php
@@ -0,0 +1,74 @@
+<?php
+	/**
+	 * Elgg system log.
+	 * Listens to events and writes crud events into the system log database.
+	 * 
+	 * @package Elgg
+	 * @subpackage Core
+	 * @license http://www.gnu.org/licenses/old-licenses/gpl-2.0.html GNU Public License version 2
+	 * @author Marcus Povey
+	 * @copyright Curverider Ltd 2008
+	 * @link http://elgg.org/
+	 */
+
+	/**
+	 * Interface that provides an interface which must be implemented by all objects wishing to be 
+	 * recorded in the system log (and by extension the river).
+	 * @author Marcus Povey
+	 */
+	interface Loggable 
+	{
+		/**
+		 * Return an identification for the object for storage in the system log. This id must be an integer.
+		 * 
+		 * @return int 
+		 */
+		public abstract function getSystemLogID();
+
+		// get object from ID .. ?
+	}
+	
+	/**
+	 * Log a system event related to a specific object.
+	 * 
+	 * @param $object The object you're talking about.
+	 * @param $event String The event being logged
+	 */
+	function system_log($object, $event)
+	{
+		global $CONFIG;
+		
+		if ($object instanceof Loggable)
+		{
+			// Has loggable interface, extract the necessary information and store
+			$object_id = (int)$object->getSystemLogID();
+			$object_class = santisise_string(get_class($object));
+			$event = sanitise_string($event);
+			$time_created = time();
+			
+			// Create log
+			return insert_data("INSERT into {$CONFIG->dbprefix}system_log (object_id, object_class, event, time_created) VALUES ('$object_id','$object_class','$event','$time')");
+		}
+	}
+	
+	/**
+	 * System log listener.
+	 * This function listens to all events in the system and logs anything appropriate.
+	 *
+	 * @param String $event
+	 * @param String $object_type
+	 * @param mixed $object
+	 */
+	function system_log_listener($event, $object_type, $object)
+	{
+		if ($object instanceof Loggable)
+		{
+			system_log($object, $event);
+		}
+		
+		return true;
+	}
+
+	/** Register event to listen to all events **/
+	register_event_handler('all','all','system_log_listener');
+?>
+\ No newline at end of file