Sign In Start Free Trial
Account

Add to playlist

Create a Playlist

Modal Close icon
You need to login to use this feature.
  • Book Overview & Buying Ext JS 3.0 Cookbook
  • Table Of Contents Toc
Ext JS 3.0 Cookbook

Ext JS 3.0 Cookbook

4.7 (6)
close
close
Ext JS 3.0 Cookbook

Ext JS 3.0 Cookbook

4.7 (6)

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)
close
close
Ext JS 3.0 Cookbook
Credits
About the Author
About the Reviewer
Preface

Running high-performance DOM queries


Now you'll see how to run queries against the DOM using Ext JS—a must-have when you need to manipulate or perform actions on multiple, related DOM elements. The examples show how to reference all the div elements in a document, obtain all the elements with a CSS class name msg, and iterate over the options of a select element.

How to do it...

The following code snippets are examples of how to run high-performance queries against the DOM using Ext JS:

  • When you need to retrieve the elements that match the div selector to find the div elements in the document, use the following code snippet:

    Ext.onReady(function() {
    // Get all the div elements.
    var nodes = Ext.query('div');
    Ext.each(nodes, function(item, index, allItems) {
    document.write(index + '<br/>');
    });
    });
    
  • When you need to reference the elements with the class name msg, use the following code snippet:

    var msgLinks = Ext.query('.msg');
    Ext.each(msgLinks, function(item,index) {
    // Do something with the element here.
    });
    
  • When you want to iterate over the options of a select element, use the following code snippet:

    var select = Ext.get('countries-select');
    Ext.each(select.options, function(item,index) {
    // Do something with the item here.
    });
    

How it works...

The previous examples use Ext.query(path, [root]), a shorthand of Ext.DomQuery.select(path, [root]), to retrieve an array of DOM nodes that match a given selector.

There's more...

DomQuery provides high-performance selector/XPath processing by compiling queries into reusable functions. It works on HTML and XML documents, supports most of the CSS3 selector's specification as well as some custom selectors and basic XPath, and allows you to plug new pseudo classes and matchers.

See also...

  • The Retrieving DOM nodes and elements recipe, covered earlier in this chapter, shows how you can use Ext JS to get a handle on any DOM element.

  • The Acquiring references to Ext JS components recipe, covered earlier in this chapter, explains how to acquire a reference to any component in your code.

CONTINUE READING
83
Tech Concepts
36
Programming languages
73
Tech Tools
Icon Unlimited access to the largest independent learning library in tech of over 8,000 expert-authored tech books and videos.
Icon Innovative learning tools, including AI book assistants, code context explainers, and text-to-speech.
Icon 50+ new titles added per month and exclusive early access to books as they are being written.
Ext JS 3.0 Cookbook
notes
bookmark Notes and Bookmarks search Search in title playlist Add to playlist font-size Font size

Change the font size

margin-width Margin width

Change margin width

day-mode Day/Sepia/Night Modes

Change background colour

Close icon Search
Country selected

Close icon Your notes and bookmarks

Confirmation

Modal Close icon
claim successful

Buy this book with your credits?

Modal Close icon
Are you sure you want to buy this book with one of your credits?
Close
YES, BUY

Submit Your Feedback

Modal Close icon
Modal Close icon
Modal Close icon