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XML DOM Level 1

The

implementation

object is a property of a DOM Document, and is, therefore, part of the browser

document

object. The sole method of

implementation

hasFeature()

, which accepts two parame-

ters: the feature to check and the version of that feature. For instance, if you want to check for support

of XML DOM Level 1, the call would be:

var bXmlLevel1 = document.implementation.hasFeature(“XML”, “1.0”);

The following table lists all the DOM features and the corresponding versions to check for:

Feature

Supported Description

Versions

Core

1.0, 2.0, 3.0 Basic DOM spelling out the use of a hierarchical tree to repre-

sent documents

XML

1.0, 2.0, 3.0 XML extension of the Core that adds support for CDATA sec-

tions, processing instructions, and entities

HTML

1.0, 2.0

HTML extension of XML that adds support for HTML-

specific elements and entities

Views

2.0

Accomplishes formatting of a document based on certain

styles

StyleSheets

2.0

Relating style sheets to documents

CSS

2.0

Support for Cascading Style Sheets Level 1

CSS2

2.0

Support for Cascading Style Sheets Level 2

Events

2.0

Generic DOM events

UIEvents

2.0

User interface events

MouseEvents 2.0

Events caused by the mouse (click, mouseover, and so on)

MutationEvents 2.0

Events fired when the DOM tree is changed

HTMLEvents 2.0

HTML 4.01 events

Range

2.0

Objects and methods for manipulating a range in a DOM tree

Traversal

2.0

Methods for traversing a DOM tree

3.0

Loading and saving between files and DOM trees

synchronously

LS-Async

3.0

Loading and saving between files and DOM trees

asynchronously

Validation

3.0

Methods to modify a DOM tree and still make it valid

Although it is a nice convenience, the drawback of using

implementation.hasFeature()

is that the

implementor

gets to decide if the implementation is indeed conformant with the various parts of the

DOM specification. It’s very easy to make this method return

true

for any and all values, but that doesn’t

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