A practical guide including examples of the new features in Ext JS 4 and tips to migrate from Ext JS 3. Migrate your Ext JS 3 applications easily to Ext JS 4 based on the examples presented in this guide Full of diagrams, illustrations, and step-by-step instructions to develop real word applications Driven by examples and explanations of how things work In Detail Ext JS 4 is a JavaScript framework that provides resources to build Rich Internet Applications with great performance. Ext JS 4 has been packed with many new features and it is difficult to master, even for seasoned experts in Ext JS 3. Ext JS 4 First Look teaches you the main functional areas of Ext JS 4 that have significant new features, explains the new features and how to use them, wh...