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

Introducing the Observer Pattern

The key concept of the Observer Pattern is that there is an object, often referred to as the observable or the subject, whose internal state changes during its lifetime. There are also several other objects, referred as the observers, that want to be notified in the event that the state of the observable/subject changes, in order to execute some operations.

The observers may need to be notified about any kind of state change of the observable or only specific types of changes. In the most common implementation, the observable maintains a list with its observers and notifies them when an appropriate state change occurs. In case a state change occurs to the observable, it iterates through the list of observers that are interested for that type of state change and executes a specific method that they have defined.

According to the definition of the Observer Pattern and the reference implementation in Computer Science books, the observers are described as objects...