Developing iOS Applications with Flex 4.5

Using Capabilities

So far you have seen how to use CSS to control some of the visual aspects of your application, but you may also wish to have only certain pieces of your application available to target specific devices or specific views created for specific devices. This is possible by utilizing the properties of the Capabilities class to determine operating system, screen resolution, and so on. The example below will serve a different home screen to the user depending on their device. This technique will allow you to target specific audiences with a custom experience. The firstView property of the ViewNavigatorApplication is bound to a function called getFirstView, which evaluates the Capabilities.version, and returns a different view based on the operating system (see Figures 7-6 and 7-7).

You could also use other properties of the Capabilities class in the same manner. You may wish to look into Capabilities.screenDPI, Capabilities.screenResolutionX, Capabilities.screenResolutionY, and Capabilities.screenColor:

Note

I could also have had just one main view file, and simply set the state of that file to be different based on the operating system.

<?xml version="1.0" encoding="utf-8"?>
<s:ViewNavigatorApplication xmlns:fx="http://ns.adobe.com/mxml/2009"
                                     xmlns:s="library://ns.adobe.com/flex/spark"
                                      firstView="{getFirstView(Capabilities.version)}">
    <fx:Declarations>
          <!-- Place non-visual elements (e.g., services, value objects) here -->
    </fx:Declarations>
    <fx:Script>
          <![CDATA[
               import ...