Flex has provided one-way data binding since its an begining
Flex 4 adds two-way data binding
With the syntax for specifying that a pair of object properties should always update each othe
<?xml version=”1.0″ encoding=”utf-8″?>
<s:Application xmlns:fx=”http://ns.adobe.com/mxml/2009″
xmlns:s=”library://ns.adobe.com/flex/spark”
xmlns:mx=”library://ns.adobe.com/flex/mx” minWidth=”955″ minHeight=”600″>
<fx:Declarations>
<!– Place non-visual elements (e.g., services, value objects) here –>
</fx:Declarations>
<mx:VBox>
<s:TextInput id=”first_txt” text=”@{second_txt.text}”/>
<s:TextInput id=”second_txt”/>
</mx:VBox>
</s:Application>
Placing an @ in front of one of the bound field values, and then leaving the other field unbound.
At this point, typing a value in one text field is mirrored in the other text field.