s:WindowedApplication is empty and does not initialize/show child components - apache-flex

Question

I have quite some experience with Flex and I am just starting to write my first AIR application and would like to use as much Spark as possible here.
So I started withe a simple Hello World application:
<?xml version="1.0" encoding="utf-8"?>
<s:WindowedApplication xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx" backgroundColor="red"
initialize="initializeHandler(event)">
<s:Label text="Hello World"/>
<s:Button label="Test" initialize="onButtonInitialize()"/>
<fx:Script><![CDATA[
import mx.events.FlexEvent;
private function onButtonInitialize():void
{
trace("Button");
}
private function initializeHandler(event:FlexEvent):void
{
trace("Application");
}
]]></fx:Script>
</s:WindowedApplication>
Unfortunately this simple example shows no child components and even none of the initialize handlers is triggered. However as soon as I change the root tag to mx:WindowedApplication everything behaves as expected: The label and the button are shown and the console shows the output of the two trace statements.
What am I missing?
I am using Flex 4.5.0 and use flex-mojos for the build.

Answer 1

I'm going to guess that it's your descriptor file that's off. Here's the default one that Flash Builder created for me:
<?xml version="1.0" encoding="utf-8" standalone="no"?>
<application xmlns="http://ns.adobe.com/air/application/2.6">
<!-- Adobe AIR Application Descriptor File Template.
Specifies parameters for identifying, installing, and launching AIR applications.
xmlns - The Adobe AIR namespace: http://ns.adobe.com/air/application/2.6
The last segment of the namespace specifies the version
of the AIR runtime required for this application to run.
minimumPatchLevel - The minimum patch level of the AIR runtime required to run
the application. Optional.
-->
<!-- A universally unique application identifier. Must be unique across all AIR applications.
Using a reverse DNS-style name as the id is recommended. (Eg. com.example.ExampleApplication.) Required. -->
<id>Airtest</id>
<!-- Used as the filename for the application. Required. -->
<filename>Airtest</filename>
<!-- The name that is displayed in the AIR application installer.
May have multiple values for each language. See samples or xsd schema file. Optional. -->
<name>Airtest</name>
<!-- A string value of the format <0-999>.<0-999>.<0-999> that represents application version which can be used to check for application upgrade.
Values can also be 1-part or 2-part. It is not necessary to have a 3-part value.
An updated version of application must have a versionNumber value higher than the previous version. Required for namespace >= 2.5 . -->
<versionNumber>0.0.0</versionNumber>
<!-- A string value (such as "v1", "2.5", or "Alpha 1") that represents the version of the application, as it should be shown to users. Optional. -->
<!-- <versionLabel></versionLabel> -->
<!-- Description, displayed in the AIR application installer.
May have multiple values for each language. See samples or xsd schema file. Optional. -->
<!-- <description></description> -->
<!-- Copyright information. Optional -->
<!-- <copyright></copyright> -->
<!-- Publisher ID. Used if you're updating an application created prior to 1.5.3 -->
<!-- <publisherID></publisherID> -->
<!-- Settings for the application's initial window. Required. -->
<initialWindow>
<!-- The main SWF or HTML file of the application. Required. -->
<!-- Note: In Flash Builder, the SWF reference is set automatically. -->
<content>[This value will be overwritten by Flash Builder in the output app.xml]</content>
<!-- The title of the main window. Optional. -->
<!-- <title></title> -->
<!-- The type of system chrome to use (either "standard" or "none"). Optional. Default standard. -->
<!-- <systemChrome></systemChrome> -->
<!-- Whether the window is transparent. Only applicable when systemChrome is none. Optional. Default false. -->
<!-- <transparent></transparent> -->
<!-- Whether the window is initially visible. Optional. Default false. -->
<!-- <visible></visible> -->
<!-- Whether the user can minimize the window. Optional. Default true. -->
<!-- <minimizable></minimizable> -->
<!-- Whether the user can maximize the window. Optional. Default true. -->
<!-- <maximizable></maximizable> -->
<!-- Whether the user can resize the window. Optional. Default true. -->
<!-- <resizable></resizable> -->
<!-- The window's initial width in pixels. Optional. -->
<!-- <width></width> -->
<!-- The window's initial height in pixels. Optional. -->
<!-- <height></height> -->
<!-- The window's initial x position. Optional. -->
<!-- <x></x> -->
<!-- The window's initial y position. Optional. -->
<!-- <y></y> -->
<!-- The window's minimum size, specified as a width/height pair in pixels, such as "400 200". Optional. -->
<!-- <minSize></minSize> -->
<!-- The window's initial maximum size, specified as a width/height pair in pixels, such as "1600 1200". Optional. -->
<!-- <maxSize></maxSize> -->
<!-- The initial aspect ratio of the app when launched (either "portrait" or "landscape"). Optional. Mobile only. Default is the natural orientation of the device -->
<!-- <aspectRatio></aspectRatio> -->
<!-- Whether the app will begin auto-orienting on launch. Optional. Mobile only. Default false -->
<!-- <autoOrients></autoOrients> -->
<!-- Whether the app launches in full screen. Optional. Mobile only. Default false -->
<!-- <fullScreen></fullScreen> -->
<!-- The render mode for the app (either auto, cpu, or gpu). Optional. Mobile only. Default auto -->
<!-- <renderMode></renderMode> -->
<!-- Whether or not to pan when a soft keyboard is raised or lowered (either "pan" or "none"). Optional. Defaults "pan." -->
<!-- <softKeyboardBehavior></softKeyboardBehavior> -->
<autoOrients>false</autoOrients>
<fullScreen>false</fullScreen>
<visible>false</visible>
</initialWindow>
<!-- We recommend omitting the supportedProfiles element, -->
<!-- which in turn permits your application to be deployed to all -->
<!-- devices supported by AIR. If you wish to restrict deployment -->
<!-- (i.e., to only mobile devices) then add this element and list -->
<!-- only the profiles which your application does support. -->
<!-- <supportedProfiles>desktop extendedDesktop mobileDevice extendedMobileDevice</supportedProfiles> -->
<!-- The subpath of the standard default installation location to use. Optional. -->
<!-- <installFolder></installFolder> -->
<!-- The subpath of the Programs menu to use. (Ignored on operating systems without a Programs menu.) Optional. -->
<!-- <programMenuFolder></programMenuFolder> -->
<!-- The icon the system uses for the application. For at least one resolution,
specify the path to a PNG file included in the AIR package. Optional. -->
<!-- <icon>
<image16x16></image16x16>
<image32x32></image32x32>
<image36x36></image36x36>
<image48x48></image48x48>
<image72x72></image72x72>
<image114x114></image114x114>
<image128x128></image128x128>
</icon> -->
<!-- Whether the application handles the update when a user double-clicks an update version
of the AIR file (true), or the default AIR application installer handles the update (false).
Optional. Default false. -->
<!-- <customUpdateUI></customUpdateUI> -->
<!-- Whether the application can be launched when the user clicks a link in a web browser.
Optional. Default false. -->
<!-- <allowBrowserInvocation></allowBrowserInvocation> -->
<!-- Listing of file types for which the application can register. Optional. -->
<!-- <fileTypes> -->
<!-- Defines one file type. Optional. -->
<!-- <fileType> -->
<!-- The name that the system displays for the registered file type. Required. -->
<!-- <name></name> -->
<!-- The extension to register. Required. -->
<!-- <extension></extension> -->
<!-- The description of the file type. Optional. -->
<!-- <description></description> -->
<!-- The MIME content type. -->
<!-- <contentType></contentType> -->
<!-- The icon to display for the file type. Optional. -->
<!-- <icon>
<image16x16></image16x16>
<image32x32></image32x32>
<image48x48></image48x48>
<image128x128></image128x128>
</icon> -->
<!-- </fileType> -->
<!-- </fileTypes> -->
<!-- iOS specific capabilities -->
<!-- <iPhone> -->
<!-- A list of plist key/value pairs to be added to the application Info.plist -->
<!-- <InfoAdditions>
<![CDATA[
<key>UIDeviceFamily</key>
<array>
<string>1</string>
<string>2</string>
</array>
<key>UIStatusBarStyle</key>
<string>UIStatusBarStyleBlackOpaque</string>
<key>UIRequiresPersistentWiFi</key>
<string>YES</string>
]]>
</InfoAdditions> -->
<!-- <requestedDisplayResolution></requestedDisplayResolution> -->
<!-- </iPhone> -->
<!-- Specify Android specific tags that get passed to AndroidManifest.xml file. -->
<!--<android>
<manifestAdditions>
<![CDATA[
<manifest android:installLocation="auto">
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-configuration android:reqFiveWayNav="true"/>
<supports-screens android:normalScreens="true"/>
<uses-feature android:required="true" android:name="android.hardware.touchscreen.multitouch"/>
<application android:enabled="true">
<activity android:excludeFromRecents="false">
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
</activity>
</application>
</manifest>
]]>
</manifestAdditions>
</android> -->
<!-- End of the schema for adding the android specific tags in AndroidManifest.xml file -->
</application>