Why is object property null?

Question

Below is my class, which simply reads an xml file and provides the contents in e4x format. Unfortunately, after the constructors executes and sets the xmlProperties property with the expected values, it some how becomes null. Anyone know what I'm doing wrong?

    public class WebService
    {
    private var _propertiesReader:HTTPService;
    private var _xmlProperties:XML;

    public function WebService()
    {
        _propertiesReader = new HTTPService();
        _propertiesReader.url = "../resources/properties.xml";
        _propertiesReader.resultFormat = "e4x";
        _propertiesReader.contentType = "application/xml";
        _propertiesReader.addEventListener(ResultEvent.RESULT, function(event:ResultEvent):void
        {
            _xmlProperties = XML(event.result);
        });
        _propertiesReader.addEventListener(FaultEvent.FAULT, function(event:FaultEvent):void 
        {
            Alert.show("Unable to load properties content: " + event.fault.message + "\nPlease try again later.", "Properties File Load Error");    
        });
        _propertiesReader.send();
    }

    public function get xmlProperties():XML
    {
        return _xmlProperties;
    }
    }

Answer 1

_xmlProperties is being set by a File Load call (via a callback event). It is not being set directly in the constructor.

Are you sure you are waiting for the call to finish and the callback event to fire before you check the value of _xmlProperty?