Book Image

Learning jQuery - Fourth Edition

By : Karl Swedberg, Jonathan Chaffer
Book Image

Learning jQuery - Fourth Edition

By: Karl Swedberg, Jonathan Chaffer

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. LearningjQuery - Fourth Edition is revised and updated version 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 take 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 Fourth Edition
Credits
Foreword
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Using deferred objects


At times we come across situations in which we want to act when a process completes, but we don't necessarily know how long the process will take or even if it will be successful. To handle these cases, jQuery offers us deferred objects. A deferred object encapsulates an operation that takes some time to complete.

A new deferred object can be created at any time by calling the $.Deferred() constructor. Once we have such an object, we can perform long-lasting operations and then call the .resolve() or .reject() methods on the object to indicate the operation was successful or unsuccessful. It is somewhat unusual to do this manually, however. Typically, rather than creating our own deferred objects by hand, jQuery or its plugins will create the object and take care of resolving or rejecting it. We just need to learn how to use the object that is created.

Note

Rather than detailing how the $.Deferred() constructor operates, we will focus here on how jQuery effects take...