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

Simulating user interaction


At times, it is convenient to execute code that we have bound to an event, even if the normal circumstances of the event are not occurring. For example, suppose we wanted our style switcher to begin in its collapsed state. We could accomplish this by hiding buttons from within the stylesheet, or by adding our hidden class or calling the .hide() method from a $(document).ready() handler. Another way would be to simulate a click on the style switcher so that the toggling mechanism we've already established is triggered.

The .trigger() method allows us to do just this:

$(document).ready(function() {
  $('#switcher').trigger('click');
});

Listing 3.23

Now when the page loads, the switcher is collapsed, just as if it had been clicked, as shown in the following screenshot:

If we were hiding content that we wanted people without JavaScript enabled to see, then this would be a reasonable way to implement graceful degradation .

The .trigger() method provides the same set of...