Variables in a class

programming flash
1

Hi there,
I had tried searching this for the last 2 hours =[ so I decided to give in and ask.

I am have a number of variables defined in my document class and I have noticed that if I were to call a function in the same class to edit the value of the variable, the change would only apply to the scope of the function.

Now I hope I used scope in the right context there =D

Here is my code to show what I mean:


package {
    import flash.display.*;
    import flash.xml.*;
    import flash.events.*;
    import com.xml.xmlLoad;
    import com.gui.mainGui;

    public class main extends MovieClip {

        private var _targetURL:String = "Musicinfo.xml";
        private var getXMLLoad:xmlLoad;
        private var getGui:mainGui;
        public var xmlData:XML;
        public var _lessonInfo:XMLList;
 
        public function main() {
            loadXML(_targetURL);
            processXML();//This will return TypeError: Error #1009: 
                               //Cannot access a property or method of a null object reference.
                                //at main/::processXML()
            trace(xmlData);//This will also return an error similar to above

        }
        function loadXML(_targetURL) {
            getXMLLoad = new xmlLoad(_targetURL);
            getXMLLoad.addEventListener(Event.COMPLETE, onComplete);
        }
        function onComplete(evt:Event) {
            xmlData = getXMLLoad.getXML();
            trace(xmlData.fileInfo.blurb);//This traces the XML data
            trace(xmlData.fileInfo.author);//And so does this
        }
        function processXML() {
            trace(xmlData.fileInfo.blurb);//This dosen't =[
        }
    }
}

Could someone explain why this is?
This may be a AS2 understanding but I thought that if I at changed the value of a variable made in the class, then the value would be the new value for every time the variable was called after the new value was put there.

2

You can’t access the xmlData variable until you’ve instantiated the variable, or it’s null.

3

Problem is you call processXML before it’s loaded. You should call the function in the onComplete handler.

4

Ok I probably thought that by the time processXML(); was called the XML would be already loaded…

Does flash process in a liner way? I thought the functions would of been run in this order:

loadXML(); -> onComplete(); -> processXML();

Therefore I thought that the value of xmlData would then be the XML file when it came to do the processXML(); function.

5

no, it will start the processXML() immediately after loadXML() unless you specifically tell it to wait until the loadXML complete event dispatches.

6

How would I do that?

EDIT::
Well thinking about it could i just add an even listener?