Specifications

287ADOBE FLEX 3

Building and Deploying Adobe Flex 3 Applications

When you set the compatibility-version option, you must be sure that the configuration files that you use are

compatible with the version you select. For example, the way that locales and metadata elements are set up in the

flex-config.xml file is different between Flex 2.0.1 and Flex 3. For a complete list of differences, see “Differences

between SDK 2.0.1 and SDK 3” on page 287.

You can programmatically access the version of the Flex application that you are running by using the

mx.core.FlexVersion class. To get the current compatibility version in your application, use the

compatibilityVersionString property of that class. This lets you conditionalize the logic in your application

based on the compatibility version.

Using themes

When you set the compatibility version, you should also be sure to use the appropriate theme file that matches

that version. For Flex 2.0.0 and 2.0.1, you should use the HaloClassic.swc theme file. Themes are located in the

frameworks/themes directory. For Flex 3, you do not have to specify a theme file. The default theme file is

designed for Flex 3 compatibility. For more information on using themes, see “About themes” on page 645 in the

Adobe Flex 3 Developer Guide.

The default style sheets for several versions of Flex are available in the framework.swc file. This SWC file contains

the current default style sheet (defaults.css), the Flex 2.0.1 default style sheet (defaults-2.0.1.css), and the Flex 2

default style sheet (defaults-2.0.0.css). The compiler uses the style sheet that is appropriate for the compatibility

version you set. For example, if you set the

compatibility-version option to 2.0.1, then the compiler uses the

Flex 2.0.1 default style sheet.

Differences between SDK 2.0.1 and SDK 3

The differences between SDK 2.0.1 and SDK 3 that result from setting the compatibility-version option are

mostly style properties and the styles applied to subcomponents.

Subcomponents are components within other components that inherited the styles of their parent in SDK 2.0.1

but do not in SDK 3. For example, the DateField control has a DateChooser subcomponent. In Flex 2.0.1, if you

set noninheritable style properties such as

borderColor or cornerRadius on the DateField control, the styles

are also applied to the DateChooser subcomponent. This resulted in unexpected styling of the subcomponent and

it was difficult to override this behavior. In Flex 3, these styles are not passed through from the DateField control

to the DateChooser subcomponent, but you can choose to pass them through.

The following application shows the difference between how a DateField control appeared in SDK 2.0.1 and how

it appears in SDK 3:

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

<!-- Compile this sample twice: once with the compatibility-version