Dojo: The Definitive Guide

Dijit for Designers

The fundamentals for using an existing dijit in markup are quite simple: a dojoType tag specifies the type of dijit that should be placed in the page, attributes pass data into the widget upon creation, and extension points allow you to override existing widget behavior. While the dojoType tag is required, attributes usually are set to reasonable default values, and extension points always fall back to a reasonable implementation.

Tip

The difference between "methods" and "extension points" is purely a semantic one: methods are operations that the application programmer call directly to control a dijit. Extension points are methods that the application programmer does not call directly; the dijits calls them itself when an appropriate condition arises. For example, a widget might have an explicit method like setValue that could be called to programmatically adjust it, while a method like onKeyUp would be an extension point in that it gets called automatically each time a key is pressed.

There are several attributes, listed in Table 11-2, that are especially important to be aware of for out-of-the-box usage because these attributes are set directly on a widget's DOM Node. These attributes ultimately ensure that the dijit's underlying HTML markup is as customizable and "proper" as possible.

A Word on DOCTYPE Validation

Technically speaking, it is possible to include dijits on pages and meet HTML 4.01 Strict DOCTYPE validation, but only if the dijits are programmatically ...