Processing XML from within a class

programming flash
1

Hi there,

I’m trying to write a trivia game, which reads in an XML file containing questions and answers. The XML file is formatted like this:


<?xml version="1.0" encoding="utr-8">
<QAnode>
	<question>What is Google Chrome?</question>
	<answerA>A new kind of metal</answerA>
	<answerB>An email client</answerB>
	<answerC>A web browser</answerC>
	<answerD>A search engine</answerD>
	<CorrAns>C</CorrAns>
</QAnode>
...(more QAnodes follow)

I’ve written a class file (TriviaGame.as) which handles the gameplay. I’d like to be able to process the XML file from within the class, via a call to initXML():

private function initXML (filename:String) {

        // Create new XML Object and set ignoreWhite true
        QA_xml = new XML ();
        QA_xml.ignoreWhite = true;

        // Setup load handler which just invokes another function
        // which will do the parsing of our XML
        var thisObj:TriviaGame = this; //Pointer to this object

        QA_xml.onLoad = function (sucess) {
            if (sucess) {
                trace ('loaded file successfully');
                thisObj.processQA(QA_xml);
                trace('completed processQA');
            } else {
                trace ('File was not loaded');
            }
        };

        // Load up the XML file into Flash
        QA_xml.load (filename);
    }

private function processQA (xmlDoc_xml) {
        //Initialize QA_array
        trace ('Inside processQA');
        
        QA_array = new Array ();
        trace('
FirstChild: 
' + xmlDoc_xml.firstChild);
        trace('
ChildNodes: 
' + xmlDoc_xml.childNodes);
        trace('
fc.fc: 
' + xmlDoc_xml.firstChild.firstChild);

        for (var n = 0; n < xmlDoc_xml.firstChild.childNodes.length; n++) {
            QA_array[n] = new Array ();

            for (var i = 0; i < xmlDoc_xml.firstChild.childNodes[n].childNodes.length; i++) {
                //place nodes values into the object
                trace('
Node value: ');
                trace(xmlDoc_xml.firstChild.childNodes[n].childNodes*.firstChild.nodeValue);
                QA_array[n]* = xmlDoc_xml.firstChild.childNodes[n].childNodes*.firstChild.nodeValue;
            }
        }

        trace('Question:' + QA_array[0][0]);
        trace('Answers:
A: ' + QA_array[0][1] + '
B: ' + QA_array[0][2] + '
C: ' + QA_array[0][3] + '
D: ' + QA_array[0][4]);
        trace('
Correct answer: ' + QA_array[0][5]);

    }

The traces are all for debug purposes. If I place this code into the actions panel of the first frame of the flash document (without the thisObj:TriviaGame = this part), everything works fine and I get correct traces.

If I place this code within TriviaGame.as, all of the traces print ‘undefined’, but it claims to have opened the file correctly. I’ve found a lot of XML tutorials on this site, but none of them seem to deal with processing XML from within a class file–they all put the code directly on the frame.

Does anyone know why it would goof up on me like this?

Thanks in advance.