↑
Main Page

XMLList

If you want to create a complete (deep) copy of some XML, you can use the

copy()

method. This

method returns an exact copy of the node and all its descendants (no ancestors are copied).

var oXml = <message>Hello World!</message>

var oNewXml = oXml.copy();

alert(oNewXml.toXMLString()); //outputs <message>Hello World!</message>

The XML object has a method called

length()

which always returns

. This may seem a silly, but it

was done to blur the distinction between

XML

objects and

XMLList

objects when writing code. Another

method,

contains()

, is equally useless in the context of XML objects, but it is included to make the

code compatible with

XMLList

objects as well. The

contains()

method returns

true

only when you

pass in the XML object calling the method, like this:

oXml.contains(oXml);

Again, these two methods have actual uses in

XMLList

, but aren’t terribly useful in

XML

The

nodeKind()

method determines what type of node an XML object represents, returning either “text”,

“element”, “comment”, “processing-instruction”, or “attribute”. Consider the following XML object:

var oXml = <employees>

<? Don’t forget the donuts! ?>

<name>Richard McMichael</name>

</employee>

<name>Rebecca Smith</name>

</employee>

</employees>

Given this XML, the following table shows what

nodeKind()

returns depending on which node is

in scope.

Statement

Returns

oXml.nodeKind()

“element”

oXml.child(0)

“processing-instruction”

oXml.employee.@position.nodeKind()

“attribute”

oXml.employee.nodeKind()

“element”

oXml.child(2)

“comment”

oXml.employee.name.child(0)

“text”

The

normalize()

method works the same way as in the DOM: It normalizes (combines) whitespace

and text between elements to create single text nodes instead of multiple ones. Not very exciting, but

necessary for dealing with XML code.

613

The Evolution of JavaScript

23_579088 ch20.qxd 3/28/05 11:44 AM Page 613