In essence, factory functions are class methods that manufacture items or other properties during the instantiation of the class. This article explains pros and cons of factory function and how to use them correctly.
If you modify records of an editable grid with paging and if you then page-out, your changes are lost. This article shows easy implementation of keeping modified records while paging.
Rich Internet Applications (RIA) consist of two parts: client side and server side. Client cannot call server functions directly but sends requests, server processes them calling the appropriate functions and returns results back to client. Ext.Direct makes it look like we are calling server methods directly at client.