implemented a basic NotificationCenter

lib/Server/NotificationCenter.js

@@ -1,7 +1,53 @@
 define(function() {
 
 	function NotificationCenter() {
+        this.topics = {};
+        this.subUid = -1;
 	}
 
+    NotificationCenter.prototype.trigger = function(topic, args) {
+        if (!this.topics[topic]) {
+            throw "No such topic " + topic + ". Could not trigger.";
+        }
+
+        var subscribers = this.topics[topic];
+        var len = subscribers ? subscribers.length : 0;
+
+        while (len--) {
+            subscribers[len].func(topic, args);
+        }
+
+        return this;
+    }
+
+    NotificationCenter.prototype.on = function(topic, func) {
+        if (!this.topics[topic]) {
+            this.topics[topic] = [];
+        }
+
+        var token = ( ++this.subUid ).toString();
+        this.topics[topic].push({
+            token: token,
+            func: func
+        });
+
+        return token;
+    }
+
+    NotificationCenter.prototype.off = function(token) {
+
+        for(var m in this.topics) {
+            if (this.topics[m]) {
+                for(var i = 0, j = this.topics[m].length; i < j; i++) {
+                    if (this.topics[m][i].token === token) {
+                        this.topics[m].splice(i, 1);
+                        return token;
+                    }
+                }
+            }
+        }
+        return this;
+    }
+
 	return NotificationCenter;
 });