HTML5 History API for Ext JS

The Ext JS framework includes the Ext.util.History component for managing the browser history that was first introduced in Ext 2.0 back in 2007. It’s pretty solid, and other than bug fixes it hasn’t changed much since then. In the reportcaster framework, all state changes while changing reports or drilling within reports is routed through a 

Ext JS: Encapsulate complex logic for cleaner code and reuse

Ext JS provides many reusable components for use in Javascript applications that shield the developer from complex timer and/or asynchronous code. However, you may still find yourself writing timing or asynchronous code directly in your application code that you would be better off encapsulating in a class. Timer code is generally not pretty, bug prone