javascript

DOM Levels 2 and 3
The first level of the DOM focuses on defining the underlying structure of HTML and XML
documents. DOM Levels 2 and 3 build upon this structure to introduce more interactivity and support
for more advanced XML features. As a result, DOM Levels 2 and 3 actually consist of several modules
that, although related, describe very specific subsets of the DOM. These modules are as follows:
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DOM Core — Builds upon the Level 1 core, adding methods and properties to nodes
DOM Views — Defines different views for a document based on stylistic information
DOM Events — Explains how to tie interactivity to DOM documents using events
DOM Style — Defines how to programmatically access and change CSS styling
information
DOM Traversal and Range — Introduces new interfaces for traversing a DOM document
and selecting specific parts of it
DOM HTML — Builds upon the Level 1 HTML, adding properties, methods, and new
interfaces
This chapter explores each of these modules except for DOM Events, which are covered fully in
Chapter 12 .
DOM Level 3 also contains the XPath module and the Load and Save module. These
are discussed in Chapter 15 .
DOM Changes
The purpose of the DOM Levels 2 and 3 Core is to expand the DOM API to encompass all of the
requirements of XML and to provide for better error handling and feature detection. For the most
part, this means supporting the concept of XML namespaces. DOM Level 2 Core doesn ’t introduce
any new types; it simply augments the types defined in DOM Level 1 to include new methods and
properties. DOM Level 3 Core further augments the existing types and introduces several new ones.