[Molecula]

Да, можно через Бинд делать:
Основное:

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" creationComplete="init()">
	<mx:Script>
		<![CDATA[
			import mx.binding.utils.ChangeWatcher;
    		import mx.binding.utils.BindingUtils;
		
			private var co:Core;
			private var __nameWatcher:ChangeWatcher;
			
			private function init():void{
				this.co = new Core();
				this.addChild(this.co);
				this.__nameWatcher = BindingUtils.bindProperty(ta, "text", this.co, "s");
				ta.text = 'Hello Budda!';
			}
			private function onClick(e:MouseEvent):void{
				this.co.pizdun();
			}
		]]>
	</mx:Script>
	<mx:TextArea id="ta" x="44" y="56"/>
	<mx:Button x="44" y="118" label="Button" click="onClick(event)"/>
</mx:Application>

AS:

package{
	import mx.core.UIComponent;
	    
	public class Core extends UIComponent{
		
		[Bindable] public var s:String;
		
		public function Core(){
			super();
		}
		public function pizdun():void{
			s = 'Hi';
		}
	}
}