It seems that Flex Builder 3 has an issue when it comes to reseting warnings about non-bindable properties.

Consider the following example:

<?xml version="1.0" encoding="utf-8"?>


            [Bindable] public var model : Model;


    <mx:Canvas height="{model.newHeight}" />


    public class Model
        public var newHeight : Number;

As you can see, the MXML file is data-binding the height property in the Canvas container to the newHeight property in the model.

If you compile this application, you should expect to receive the following warning:

Data binding will not be able to detect assignments to “newHeight”

To resolve this, you just need to make the newHeight property bindable. No big deal.

However if you make this change and recompile the application, the warning about the property will not disappear.

It seems that the compiler is not so smart when it comes to bindable property changes. If you go back and edit the MXML file, or clean the project and recompile, the warning will disappear.

While this is nothing more than an annoyance, it’s always good to know that’s it’s not a problem with your code. 🙂