Update on the Work of the W3C DOM Activity

Web scripting

Markup languages such as HTML or SVG provide different ways to include or link programming scriptings to the document. In order to use scripting capabilities on the Web, it is recommend to read the Web Content Accessibility Guidelines   before using scripts in your documents, in particular the guideline 6.

Specifications of existing scripting languages such as ECMAScript   (an industry-standard scripting language based on JavaScript and JScript) only give the syntax, the grammar and the basic types' functionalities (String, Object, Number, ...). These specifications don't give the user access to the user agent functionalities (menus, scrollbars, user events, ...) or to the document (text contents, markup structure, style sheets, ...). This is where the Document Object Model stands in the context of scripting.

XML Applications

In November 1996, the W3C released the first Working Draft of the XML specification  . Many applications of XML were done since then: editors, repositories, databases, B2B systems, Web content, network protocols, etc.

The XML specification only provides the syntax and the grammar for XML. Being able to access the XML content in an application requires more than that: it requires an Application Programming Interface (API).

Tree-based API

Generic APIs for XML can be mostly classified in two categories: event-based or tree-based. The DOM is a generic tree-based API for XML. For more information about event-based APIs and a comparison with tree-based APIs, read the   documentation " " or the DOM Frequently asked question (FAQ) " ".

Example of DOM usage

// get the HTML body element from the document
      var childs = doc.getElementsByTagName("body");
      // there is one HTML body element for each HTML 4.0 document
      var body   = childs.item(0);
      // change the value of the CSS2 color property
      body.style.color = "black";

For a more advanced example, check the DOM Level 2 demo used in the main DOM page  .

DOM Requirements

The DOM requirements contains all requirements for the Levels of DOM. It is regularly updated to reflect the requirements of the latest Level.

DOM Level 0

Functionality equivalent to that exposed in Netscape Navigator 3.0 and Microsoft Internet Explorer 3.0 is referred to as "Level 0". There is no W3C specification for this Level.

DOM Level 1

The first Level of the DOM specifications, DOM Level 1, was completed in October 1998. Level 1 provides support for XML 1.0 and HTML.

DOM Level 2

The second Level of the DOM specifications, DOM Level 2, was completed in November 2000. Level 2 extends Level 1 with support for XML 1.0 with namespaces and adds supports for Cascading Style Sheets (CSS), events (user interface events and tree manipulation events), and enhances tree manipulations (tree ranges and traversal mechanisms).

DOM Level 3

The presentation will provide the current status of the DOM Level 3 since it is the one currently under development in the W3C.

The third Level of the DOM specifications, DOM Level 3, is under development. Level 3 will extend Level 2 by finishing support for XML 1.0 with namespaces (alignment with the XML Infoset and support for XML Base) and will extend the user interface events (keyboard). It will also add abstract schemas support (for DTDs, XML Schema, ...), the ability to load and save a document or an abstract schema, explore further mixed markup vocabularies and the implications on the DOM API ("Embedded DOM"), and will support XPath.

DOM Conformance Test Suites

The DOM Test Suites are currently under development in the DOMTS public forum  . This works is being done by the NIST , the W3C , and the public. The tests are described in XML, using the XML sources of the DOM specifications. The purpose is to provide conformance test suites for Java and ECMAScript but it is certainly not restricted to these two languages. A report on the current situation of this work will be presented during the talk.