In Flex 3 we created a data binding expression using curly braces, like so:
<TextInput label="textInput1" />
<TextInput label="textInput2" text="{textInput1.text}" />
In Flex 3 if you wanted to make the binding two-way, you had to make a second binding expression. However, in Flex 4 you can just add an @ sign to the binding expression to make it two-way, like this:
<s:TextInput label="textInput1" />
<s:TextInput label="textInput2" text="@{textInput1.text}" />
