Professional JavaScript For Web Developers

Chapter 15
Because the xml property needs to be available on every type of node in a document, it’s best to add it to
the Node class itself (remember, all other node types inherit from Node):
Node.prototype.__defineGetter__(“xml”, function () {
var oSerializer = new XMLSerializer();
return oSerializer.serializeToString(this, “text/xml”);
});
The function assigned to the xml property is very simple, and the only change from the earlier example
is that this is the first argument for the serializeToString() method (remember, in this context
this refers to the node). If you include this code in a page, it’s possible to use this custom xml property
in the same manner as Microsoft’s xml property:
oXmlDom.load(“test.xml”);
alert(oXmlDom.xml);
var oNode = oXmlDom.documentElements.childNodes[1];
alert(oNode.xml);
This code must also be surrounded by a browser detect because it only works in
Mozilla.
Parsing errors
When an error occurs in the parsing of an XML file, the XML DOM creates a document explaining the
error. Suppose you ran the following code:
var oParser = new DOMParser()
var oXmlDom = oParser.parseFromString(“”);
Although no error is thrown, oXmlDom shows you the error. In this case, it presents this code:
XML Parsing Error: not well-formed
Location: file://c:/Chapter 15/examples/MozillaXmlDomExample.htm
Line Number 5, Column 1:<root><child></root>
--------------^
So to determine if there’s an error in the parsing of XML code, you must test the tag name of the document
element:
if (oXmlDom.documentElement.tagName != “parsererror”) {
//continue on, no errors
} else {
//do something else, there was an error
}
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