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, while highlighting the differences between Ext JS 4 and the previous versions. This book will give you the knowledge to make the required changes to Ext JS 3 application to build a complete Ext JS 4 application. This book provides examples of how to load Ext JS components by demand, charts, grid, tree, forms and panels, new data model, themes and mvc architecture. Ext JS 4 First Look provides full examples and illustrations to help you easily learn the new features of Ext JS 4. What you will learn from this book Learn the major changes in Ext JS 4 and its compatibility with Ext JS 3, including how to load components by demand. Understand how to use the new Data package, including new features such as Model, Associations, Validations, new Proxies, etc. Organize Ext JS 4 components into containers using upgraded and new Layout engines. Create bar, pie, radar, scatter, gauge, line, and area charts without using Flash and customize them. Learn what has changed in Ext JS 4 components such as Grid, Tree, Form.s Change and create new themes using Sass and Compass. Build a complete application using the new Ext JS MVC architecture. Compare Ext JS 3 with Ext JS 4 class names. Approach This book is a practical step-by-step tutorial which guides you to migrate from Ext JS 3 to Ext JS 4. There are examples backed with explanations and plenty of code and illustrations to look forward to. Who this book is written for This book is written for web developers who are familiar with Ext JS 3 and want to have detailed insights into the new features of Ext JS 4.