Book Image

jQuery Design Patterns

By : Thodoris Greasidis
Book Image

jQuery Design Patterns

By: Thodoris Greasidis

Overview of this book

jQuery is a feature-rich JavaScript library that makes HTML document traversal and manipulation, event handling, animation, and Ajax much simpler with an easy-to-use API that works across a variety of browsers. With a combination of versatility and extensibility, jQuery has changed the way that millions of people write JavaScript. jQuery solves the problems of DOM manipulation, event detection, AJAX calls, element selection and document queries, element attribute and data management, as well as object management utilities. This book addresses these problems and shows you how to make the best of jQuery through the various design patterns available. The book starts off with a refresher to jQuery and will then take you through the different design patterns such as facade, observer, publisher/subscriber, and so on. We will also go into client-side templating techniques and libraries, as well as some plugin development patterns. Finally, we will look into some best practices that you can use to make the best of jQuery.
Table of Contents (18 chapters)
jQuery Design Patterns
About the Author
About the Reviewer

Optimizing common JavaScript code

In this section, we will analyze some performance tips that are not jQuery-specific and can be applied to most JavaScript implementations.

Writing better for loops

When iterating over the items of an array or an array-like collection with a for loop, a simple way to improve the performance of the iteration is to avoid accessing the length property on every loop. This can easily be done by storing the iteration length to a separate variable, declared just before the loop or even along with it, as shown below:

for (var i = 0, len = myArray.length; i < len; i++) { 
    var item = myArray[i]; 

Moreover, if we need to iterate over the items of an array that does not contain falsy values, we can use an even better pattern which is commonly applied for iterating over arrays that contain objects:

var objects = [{ }, { }, { }]; 
for (var i = 0, item; item = objects[i]; i++) { 

In this case, instead of relying on the length property...