Book Image

Learning Ext JS 3.2

By : Shea Frederick, Colin Ramsay, Steve 'Cutter' Blades, Nigel White
Book Image

Learning Ext JS 3.2

By: Shea Frederick, Colin Ramsay, Steve 'Cutter' Blades, Nigel White

Overview of this book

<p>As more and more of our work is done through a web browser, and more businesses build web rather than desktop applications, users want web applications that look and feel like desktop applications. Ext JS is a JavaScript library that makes it (relatively) easy to create desktop-style user interfaces in a web application, including multiple windows, toolbars, drop-down menus, dialog boxes, and much more. Yet, most web developers fail to use this amazing library to its full power.</p> <p>This book covers all of the major features of the Ext framework using interactive code and clear explanation coupled with loads of screenshots. Learning Ext JS will help you create rich, dynamic, and AJAX-enabled web applications that look good and perform beyond the expectations of your users.</p> <p>From the building blocks of the application layout, to complex dynamic Grids and Forms, this book will guide you through the basics of using Ext JS, giving you the knowledge required to create rich user experiences beyond typical web interfaces. It will provide you with the tools you need to use AJAX, by consuming server-side data directly into the many interfaces of the Ext JS component library. You will also learn how to use all of the Ext JS widgets and components smartly, through interactive examples.By using a series of straightforward examples backed by screenshots, Learning Ext JS 3.2 will help you create web applications that look good and perform beyond the expectations of your users.</p>
Table of Contents (22 chapters)
Learning Ext JS 3.2
Credits
About the Authors
About the Reviewers
Preface

Registering an interest


We've already discussed how the child nodes of a DragZone must be registered in the Ext.dd.Registry before they can be dragged around. This extra step can be a little painful, and we'll see ways around this later, but for now, let's concentrate on the advantages you get when a node is added to the Ext.dd.Registry.

In our previous examples, we used the Ext.dd.Registry.register method with a single parameter: the element to be registered. However, register also takes a second, optional parameter that allows you to add an extra metadata object to the item being dragged around. This metadata can be leveraged in any way you see fit for your application, but a possible use would be to pass "compatibility" information to the drop event. Imagine you are producing an application that lets you assemble a "virtual outfit" by dragging and dropping items of clothing. We could use metadata to make sure that only items of clothing from the "summer" range can be combined, by including...