Book Image

Learning jQuery - Fourth Edition - Fourth Edition

Book Image

Learning jQuery - Fourth Edition - Fourth 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. 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

Customizing and optimizing selectors


The many techniques we've seen give us a tool chest that can be used to find any page element we want to work with. The story doesn't end here though; there is much to learn about performing our element-finding tasks efficiently. This efficiency can take the form of both code that is easier to write and read, and code that executes more quickly inside the web browser.

Writing a custom selector plugin

One way to improve legibility is to encapsulate code snippets in reusable components. We do this all the time by creating functions. In Chapter 8, Developing Plugins, we expanded this idea by crafting jQuery plugins that added methods to jQuery objects. This isn't the only way plugins can help us reuse code, though. Plugins can also provide additional selector expressions, such as the :paused selector that Cycle gave us in Chapter 7, Using Plugins.

The easiest type of selector expression to add is a pseudo-class. This is an expression that starts with a colon...