Check and download expansion files using the ExpansionFiles ANE

distriqt.extension.expansionfiles.download.as

public static const BASE64_PUBLIC_KEY	: String = "YOUR_LICENSING_PUBLIC_KEY";
public static const SALT		: Vector.<int> = Vector.<int>( [ 1, 43, -12, -1, 54, 98, -100, -12, 43, 2, -8, -4, 9, 5, -106, -108, -33, 45, -1, 84 ]); 

...

ExpansionFiles.init( "APP_KEY" );
if (ExpansionFiles.isSupported)
{
	ExpansionFiles.service.setup( BASE64_PUBLIC_KEY, SALT );
	
	ExpansionFiles.service.addEventListener( ExpansionFilesEvent.CONNECTED,     connectedHandler );
	ExpansionFiles.service.addEventListener( ExpansionFilesEvent.STATE_CHANGED, stateChangedHandler );
	ExpansionFiles.service.addEventListener( ProgressEvent.PROGRESS,            progressHandler );
	ExpansionFiles.service.addEventListener( ExpansionFilesEvent.COMPLETE,      completeHandler );
	
	// Add the details of your expansion file(s)
	var expansionFile:ExpansionFile = new ExpansionFile( ExpansionFile.MAIN, 1001002, 233017 );
	ExpansionFiles.service.addExpansionFile( expansionFile );
	
	// Check if the files have been delivered / downloaded already
	if (!ExpansionFiles.service.expansionFilesDelivered())
	{
		// Start the downloading
		ExpansionFiles.service.download();
	}
	else
	{
		// Already have expansion files - use as required
	}
}

...

private function connectedHandler( event:ExpansionFilesEvent ):void
{
	trace( "connectedHandler()" );
}

private function stateChangedHandler( event:ExpansionFilesEvent ):void
{
	trace( "stateChangedHandler(): " + event.state );
}

private function completeHandler( event:ExpansionFilesEvent ):void
{
	trace( "completeHandler()" );
	// Read your expansion files
}

private function progressHandler( event:ProgressEvent ):void
{
	trace( "progressHandler( " + event.progress.toString() + " )" );	
}

// com.distriqt.ExpansionFiles

http://airnativeextensions.com/extension/com.distriqt.ExpansionFiles