PSR-0 compliance

Observer/UserObserver.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace DesignPatterns\Observer;
+
+/**
+ * Observer pattern
+ *
+ * Purpose:
+ * to implement a publish/subscribe behaviour to an object, whenever a "Subject" object changes it's state, the attached
+ * "Observers" will be notified. It is used to shorten the amount of coupled objects and uses loose coupling instead
+ *
+ * Examples:
+ * - a message queue system is observed to show the progress of a job in a GUI
+ *
+ * PHP already defines two interfaces that can help to implement this pattern: SplObserver and SplSubject
+ *
+ */
+class UserObserver implements \SplObserver
+{
+
+    public function update(\SplSubject $subject)
+    {
+        echo get_class($subject) . ' has been updated';
+    }
+
+}