ActionScript 3.0 :: Called Before Info Is Loaded

In my document class I have the following.
 
var mainBoards:LoadXMLData = new LoadXMLData("Main_boards.xml");
var test:XML = mainBoards.getXMLData;
 
In the LoadXMLData class I have an event listener and a getter that will return the XML data. 
 
_urlLoader.addEventListener(Event.COMPLETE, onDataLoaded);
_urlLoader.load(new URLRequest(file));
//and

[Code]....
 
is there a better way to wait until the data from the XML is loaded into the LoadXMLData object before the mainBoards.getXMLData is assigned to the test variable in my document class?