The image below shows the default rules that form part of the View Node. The first rule is activated during the incoming request leg of the message flow. This is used to locate and forward the request to the appropriate controller. The second rule is activated on the outgoing response leg, which essentially transforms the message response from the controller to create the XHTML. The third rule is the same as the second, but accounts for language translations. The view node is just like any other controller, which means you can add your own rules here if required. For example, you may decide to check for an error fragment and respond with a different page if errors are found. This can be done by simply changing the page name.
Please see section on Message Wrappers for a description of the message fragment shown on the left. The is the default WebMaker message wrapper used to organise information between the client and the WebMaker server environment.