Promises, Promises

This session, with Premasagar Rose and Aaron Acerboni, is an introduction to asynchronous flow control in JavaScript. We’ll be looking at how to cleanly handle multiple callbacks from Ajax requests, setTimeouts, loading images and other asynchronous routines. In particular, we’ll focus on jQuery.Deferred, which implements the Promises design pattern.

We’ll work through some practical, step-by-step code examples, looking at how jQuery uses promises with all of its Ajax methods, see how they can control and interact with jQuery’s animation effects, and how jQuery.Deferred can be used to create custom promises that control the flow of a website or web application.