Ext Core Question:

Developers should appreciate the well-thought-out design and implementation of Ext JS. Its object-oriented design patterns influence the relationship and interactions between objects. According to Ext JS, the design patterns used in their development were highly influenced by the book, Head First Design Patterns, by Freeman and Freeman (see Resources). Developers looking at the Ext JS source code will find creational patterns, including the singleton design pattern; structural patterns, including the flyweight design pattern; and behavioral patterns, including the observer pattern.