add a getter for the extension of of a filename in the uri class

Author: p01

src/scripts/uri.js

@@ -39,6 +39,23 @@ var URIPrototype = function(uri_prop_name)
 
   }, this);
 
+  this.__defineGetter__("extension", function()
+  {
+        
+    if (!this._extension && (this._is_parsed || this[uri_prop_name]))
+    {
+      var pos = this.filename.lastIndexOf(".");
+      if (pos > -1)
+        this._extension = this.filename.slice(pos + 1);
+      else
+        this._extension = "";
+    }
+
+    return this._extension;
+  });
+
+  this.__defineSetter__("extension", function() {});
+
   this.__defineGetter__("filename", function()
   {