XML in a Nutshell, 3rd Edition

Name

hasFeature: feature, version

Synopsis

Tests to see if the DOM implementation supports a specific version of a named feature package.

Arguments

feature: DOMString

The package name of the feature to test. The following feature names (and others listed at http://www.w3.org/TR/DOM-Level-2-Core/introduction.html-ID-Conformance) are valid:

XML

Supports DOM Level 1.0 or 2.0 Core objects.

HTML

Supports DOM Level 1.0 or 2.0 HTML objects.

version: DOMString

Represents the DOM version level of the specified feature to test. If no version number is specified, the function returns true if any version is supported.

Return value

Returns true if the particular version of the specified feature is available; otherwise, it returns false.

Java binding

public boolean hasFeature(String feature, String version);

Java example

// Make sure that DOM Level 1 XML is supported
if (!di.hasFeature("XML", "1.0")) {
    return null;
}

Tip

The HTML-specific DOM objects are beyond the scope of this book, but they are extremely useful tools for building applications that perform transformations on HTML documents. An excellent reference to the HTML DOM objects can be found in the book Dynamic HTML: The Definitive Reference, by Danny Goodman (O’Reilly).