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

Using a progress bar to report progress updates


As its name indicates, a progress bar can be used to notify the user that progress is being made at each step of a long-running operation.

This recipe explains how it is accomplished by using a progress bar to indicate when each of the 10 steps of a fictitious long-running operation are executed:

How to do it...

  1. 1. Create an object that will encapsulate the simulation of a long-running operation:

    var Loader = function() {
    }
    
  2. 2. Inside the Loader class, create a function that will update the progress bar status:

    var f = function(v, pbar, btn, count, cb) {
    return function() {
    if (v > count) {
    btn.dom.disabled = false;
    cb();
    }
    else {
    pbar.updateProgress(v / count, 'Loading item ' + v + ' of ' + count + '...');
    }
    };
    };
    
  3. 3. The start() method of the Loader class will trigger the simulation of a long-running operation:

    return {
    start: function(pbar, btn, count, cb) {
    btn.dom.disabled = true;
    var ms = 5000 / count;
    for (var i = 1; i < (count + 2...