In this book we're going to be building a small invoice application. This will help us learn the most commonly used components in the library and the way they interact with each other. Most of the code and examples presented in this book are used to create the UI for the final application.
There are two approaches when we develop an application with Ext JS. We can use only a few widgets and render them within the HTML page in a specific
div element along with other things and load as many pages as the system needs just like any other traditional web application. This is the first approach.
The second approach is to create a single web page application and only load data using Ajax and REST to transfer our data using JSON ...