Dojo: The Definitive Guide

Chapter 3. Event Listeners and Pub/Sub Communication

Base provides extremely useful and versatile utilities for communication between JavaScript objects, DOM nodes, and any combination thereof. This chapter introduces these constructs as well as guidelines for when each of them might be most appropriate to employ. As writing portable code that involves DOM events necessarily depends on a standardized event model, you'll also learn a little bit about how Dojo works behind the scenes to smooth out some of the inconsistencies amongst mouse and keyboard events. The chapter concludes with a discussion of publish/subscribe communication, which provides a great vehicle for realizing an architecture with loosely coupled components.

Event and Keyboard Normalization

Some of the oldest code in the toolkit was written to smooth out inconsistencies with the underlying event model amongst different browsers. This section provides a brief overview of the events that you can count on being normalized when you use Dojo to develop an application. The basis of standardization is the W3C model.

Mouse and Keyboard Event Normalization

The dojo.connect machinery that you'll read about in the following section often involves a mouse event on a particular DOM node. Whenever you use Dojo, you can rest assured that the following mouse and keyboard events are supported in accordance with the W3C standard:

onclick

onmousedown

onmouseup

onmouseover

onmouseout

onmousemove

onkeydown

onkeyup

onkeypress

Tip

In addition to supporting ...