Linking a class to a dynamic text field to load XML data.

Question

Hi,
I'm quite new to ActionScript and would be grateful for any help here.
I want to load text into a dynamic text field (called 'about_tab') using  a class depending on the language selected (by clicking on a flag icon)  by the user.
I managed to get this to work when the ActionScript was written directly  in the timeline, but am having problems with doing the same thing via a  class.
This is my class file:
package
import flash.display.SimpleButton;
import flash.display.MovieClip;
import flash.events.MouseEvent;
import flash.net.URLRequest;
import flash.net.URLLoader;
import flash.events.Event;
public class ChangeLang extends SimpleButton
public function ChangeLang()
addEventListener(MouseEvent.CLICK, switchLang);
trace("ChangeLang class working");
public function switchLang(event:MouseEvent):void
var lang = event.target.name;
var req:URLRequest = new  URLRequest("languages/"+lang+".xml");
var loader:URLLoader = new URLLoader();
var substance:XML;
function xmlLoaded(event:Event):void
trace("function xmlLoaded is running");
substance = new XML(loader.data);
about_tab.text =  substance.about_lbl;
loader.addEventListener(Event.COMPLETE, xmlLoaded);
loader.load(req);
Here's one of my XML files (the other is the same except "About" is  written in German):
<substance>
<about_lbl>About</about_lbl>
</substance>
When I run it, it returns my trace statements that the class ChangeLang  and the function xmlLoaded are running, but no text appears in the  dynamic text field (I should/want to see the word 'About'). I get this  error message:
1120: Access of undefined property about_tab
The problem, I'm guessing, is in the part in red in my code. I think I need to target the text field in the display list by creating a  reference to it. If so, could someonw point out how I do this, or perhaps a tutorial that would help. I've tried adding the word stage (i.e.,stage.about_tab.text =  substance.about_lbl; ) but it still doesn't connect. I guess there's something really simple I'm missing, so I  apologize if this comes across as a stupid question
Thanks for any help.

Answer 1

Hello flashrocket!
I'm also new to AS3 and I've just started using external classes and I think I know what you should do to put your code to work.
Instead of using the text field you created inside your flash file, why don't you use the "TextField" class to create an instance of this object? It's the exact same thing as when you create and instantiate a new text field inside Flash.
First, import flash.text.*; (includes classes like TextField, TextFieldAutoSize, TextFormat, TextFormatAlign, etc)
Than you just have to create a var like
public var about_tab : TextField;
or
public var about_tab : TextField = new TextField();
then, to adjust the properties of this tab you use dotsyntax as if it where on your stage like:
about_tab.x = 50; about_tab.alpha = .5; etc...
you can even create a function to "config your textField"
          private function createAndConfigTextField() : void {
               about_tab = new TextField(); //you only need this line if you
          // only typed something like "public var about_tab:TextField;
          // if instead you used "public var about_tab:TextField = new TextField(); outside
          // this function, just skip this first line because you already have an instance of
          // text field named "about_tab"...
                        about_tab.autoSize = TextFieldAutoSize.CENTER;
               about_tab.background = true;
               about_tab.border = true;
               var aboutTextFormat : TextFormat = new TextFormat();
               format.font = "Arial";
               format.color = 0x000000;
               format.size = 11;
               format.bold = true;
               format.align = TextFormatAlign.CENTER;
               about_tab.defaultTextFormat = aboutTextFormat;
               addChild(about_tab);
This is just an example of what you can do... I hope you get it... let me know if you have any doubt...