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
About the Author
About the Reviewer

Effortless range checking for numbers

Now, you'll see how to use Ext JS in order to guarantee that a number falls within a certain range.

How to do it...

The following steps illustrate how to perform range checking on numeric values:

  1. 1. Create your sample numbers:

    var number1 = 30;
    var number2 = 75;
  2. 2. Check whether your numbers are within a range:

    var constrained = number1.constrain(25, 50);
    // constrained is 30 because number1 is
    // within the specified range
    constrained = number2.constrain(25, 50);
    // constrained is 50 because number2 is
    // greater than the max. value in the range

How it works...

Ext.Number is a one-function extension of the JavaScript Number object. The only function of Ext.Number is constrain(min, max), which simply uses methods of the Math JavaScript object to accomplish the range checks on the given number.

constrain: function(min, max) {
return Math.min(Math.max(this, min), max);