Code Gallery - Factory Pattern in JavaScript. Singleton Pattern. Motivation Sometimes it's important to have only one instance for a class.
For example, in a system there should be only one window manager (or only a file system or only a print spooler). Usually singletons are used for centralized management of internal or external resources and they provide a global point of access to themselves. The singleton pattern is one of the simplest design patterns: it involves only one class which is responsible to instantiate itself, to make sure it creates not more than one instance; in the same time it provides a global point of access to that instance. JavaScript Programming Patterns. JavaScript is meant to be used to add behaviour to a website, might it be for form validation or for more complex operations like drag & drop functionality or performing asynchronous requests to the webserver (aka Ajax).
During the past few years, JavaScript libraries became increasingly popular. One of the reasons is definitely that websites are getting more and more complex and reinventing the wheel each time is not acceptable if you are working on a tight schedule. But letting aside libraries and focusing on the “bare” syntax of JavaScript, it is very valuable to know what kind of options you have in terms of programming patterns when writing JavaScript. JavaScript Patterns.