Book Image

Learning jQuery, Third Edition

Book Image

Learning jQuery, Third Edition

Overview of this book

To build interesting, interactive sites, developers are turning to JavaScript libraries such as jQuery to automate common tasks and simplify complicated ones. Because many web developers have more experience with HTML and CSS than with JavaScript, the library's design lends itself to a quick start for designers with little programming experience. Experienced programmers will also be aided by its conceptual consistency.Learning jQuery Third Edition is revised and updated for version 1.6 of jQuery. You will learn the basics of jQuery for adding interactions and animations to your pages. Even if previous attempts at writing JavaScript have left you baffled, this book will guide you past the pitfalls associated with AJAX, events, effects, and advanced JavaScript language features.Starting with an introduction to jQuery, you will first be shown how to write a functioning jQuery program in just three lines of code. Learn how to add impact to your actions through a set of simple visual effects and to create, copy, reassemble, and embellish content using jQuery's DOM modification methods. The book will step you through many detailed, real-world examples, and even equip you to extend the jQuery library itself with your own plug-ins.
Table of Contents (24 chapters)
Learning jQuery Third Edition
Credits
Foreword
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

The journey of an event


When an event occurs on a page, an entire hierarchy of DOM elements gets a chance to handle the event. Consider a page model similar to the following screenshot:

<div class="foo">
  <span class="bar">
    <a href="http://www.example.com/">
      The quick brown fox jumps over the lazy dog.
    </a>
  </span>
  <p>
    How razorback-jumping frogs can level six piqued gymnasts!
  </p>
</div>

We then visualize the code as a set of nested elements, as shown in the following figure:

For any event, there are multiple elements that could logically be responsible for reacting. When the link on this page is clicked, for example, the <div>, <span>, and <a> all should get the opportunity to respond to the click. After all, the three are all under the user's mouse cursor at the time. The <p> element, on the other hand, is not part of this interaction at all.

One strategy for allowing multiple elements to respond...