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

Drag-drop groups


We started off our tour of Ext.dd by looking at how individual nodes could be moved around the screen and placed in designated containers. From there, we described the methods used to enable dragging for many nodes at once, and how these could be dropped within containers with child nodes.

When you're dealing with lots of draggable elements, there's a third facility that can be used to make sure that your nodes behave in the way you'd expect: drag-drop groups. DragSource, DragZone, DropTarget, and DropZone accept the configuration option ddGroup that in turn accepts a string identifier indicating which group you'd like to assign your instance to.

But what does this configuration option actually do, in practical terms, and what new features does it provide for your applications? Well, strictly speaking, it means that a drag-drop class instance will only be able to interact with other drag-drop instances in the same group, but that's a rather dry way of explaining it. Let...