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initError

for (var i=0; i < arrSignatures.length; i++) {

try {

var oXmlDom = new ActiveXObject(arrSignatures[i]);

return oXmlDom;

} catch (oError) {

//ignore

}

throw new Error(“MSXML is not installed on your system.”);

} else if (document.implementation && document.implementation.createDocument) {

var oXmlDom = document.implementation.createDocument(“”,””,null);

oXmlDom.parseError = {

valueOf: function () { return this.errorCode; },

toString: function () { return this.errorCode.toString() }

};

oXmlDom.__initError__();

oXmlDom.addEventListener(“load”, function () {

this.__changeReadyState__(4);

}, false);

return oXmlDom;

} else {

throw new Error(“Your browser doesn’t support an XML DOM object.”);

}

This code uses object literal notation to create the

parseError

object in order to save space. The

valueOf()

method is defined to return the

errorCode

property, which is the same as IE’s implementation; the

toString()

method also returns the

errorCode

property, but as a string primitive. The

initError()

method initializes all the

parseError

object’s properties. Here’s the code:

Document.prototype.__initError__ = function () {

this.parseError.errorCode = 0;

this.parseError.filepos = -1;

this.parseError.line = -1;

this.parseError.linepos = -1;

this.parseError.reason = null;

this.parseError.srcText = null;

this.parseError.url = null;

};

The next step is to check for a parsing error. This must be done in both the

load()

and

loadXML()

meth-

ods because a parsing error can occur in either one. Because it’s bad coding practice to have the same code

in two places, it’s best to create a new method to handle parsing errors:

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