Book Image

Ext JS 3.0 Cookbook

Book Image

Ext JS 3.0 Cookbook

Overview of this book

Using Ext JS you can easily build desktop-style interfaces in your web applications. Over 400,000 developers are working smarter with Ext JS and yet most of them fail to exercise all of the features that this powerful JavaScript library has to offer. Get to grips with all of the features that you would expect with this quick and easy-to-follow Ext JS Cookbook. This book provides clear instructions for getting the most out of Ext JS with and offers many exercises to build impressive rich internet applications. This cookbook shows techniques and "patterns" for building particular interface styles and features in Ext JS. Pick what you want and move ahead. It teaches you how to use all of the Ext JS widgets and components smartly, through practical examples and exercises. Native and custom layouts, forms, grids, listviews, treeviews, charts, tab panels, menus, toolbars, and many more components are covered in a multitude of examples.The book also looks at best practices on data storage, application architecture, code organization, presenting recipes for improving themóour cookbook provides expert information for people working with Ext JS.
Table of Contents (15 chapters)
Ext JS 3.0 Cookbook
Credits
About the Author
About the Reviewer
Preface

Implementing state preservation with cookies


In this recipe, you will learn to use the state management features in Ext JS for preserving the selected tab in a TabPanel across page loads. Specifically, the selected tab's ID will be saved to and read from a cookie.

A notification of a State Change event will be displayed upon selecting a tab, as shown in the following screenshot:

As seen in the following screenshot, after a page reload, the TabPanel recovers its previous state:

How to do it...

  1. 1. Create a naming container for your code:

    Ext.ns('Example');
    
  2. 2. Define the StatefulTabPanel class as an extension of Ext.TabPanel and configure the state management options:

    Example.StatefulTabPanel = Ext.extend(Ext.TabPanel, {
    stateEvents: ['tabchange'],
    getState: function() { return { tab: this.getActiveTab().id} },
    applyState: function(state) { this.setActiveTab(state.tab); }
    });
    
  3. 3. Define the state provider, a CookieProvider instance:

    Ext.onReady(function() {
    var cp = new Ext.state.CookieProvider(...