Introduction
jQuery enables developers to build on top of the features of the core library by creating plugins. A plugin is basically an extension of the core library. It is a JavaScript file that is included on web pages along with the jQuery library. It usually provides a set of configurable items that developers can use to customize according to the requirements of their applications.
A wide variety of useful plugins are written and available for use. They cover many aspects of development, such as animations, graphics, forms, UI, and responsiveness. To maintain all plugins in a centralized location, a plugin repository was launched at http://plugins.jquery.com in 2013. However, this site now offers a read-only access to plugins and new releases can be made to the NPM (Node Package Manager). Plugins can be downloaded and used from the NPM.
In this chapter, let's get started with creating our own plugins. We will also download and use a popular jQuery plugin for validation of forms.