The goal of persisting state between sessions is to allow a user to return to a screen that they had previously customized. Ext JS 4 enables you to save the current state of windows, grids, and panels in a border layout.
Other Ext components can be extended to be state-aware for application specific uses.
Saving state information as browser cookies or into HTML5 localstorage is directly supported by Ext, however, the framework does not include a state provider for storing state information on an application server. Check out Steve Drucker's latest blogpost to learn how to preserve stateful information on a server. http://druckit.wordpress.com/2013/07/11/ext-js-4-preserving-state-on-the-server-2/