Calling AppleScript from Swift App, passing a parameter

gistfile1.txt

// Swift version of https://developer.apple.com/library/mac/technotes/tn2084/_index.html

	@IBAction func testButtonPushed(sender: AnyObject) {
		
		let URL = NSBundle.mainBundle().URLForResource("SendFinderMessage", withExtension: "scpt")!
		
		var errors: NSDictionary?
		let script = NSAppleScript(contentsOfURL: URL, error: &errors)!
		
		let message = NSAppleEventDescriptor(string: "Message from App")
		
		let parameters = NSAppleEventDescriptor.listDescriptor()
		parameters.insertDescriptor(message, atIndex: 1)
		
		var psn = ProcessSerialNumber(highLongOfPSN: UInt32(0), lowLongOfPSN: UInt32(kCurrentProcess))

		let target = NSAppleEventDescriptor(descriptorType: DescType(typeProcessSerialNumber), bytes:&psn, length:sizeof(ProcessSerialNumber))
		
		let handler = NSAppleEventDescriptor(string: "show_message")
		
		let event = NSAppleEventDescriptor.appleEventWithEventClass(AEEventClass(kASAppleScriptSuite), eventID: AEEventID(kASSubroutineEvent), targetDescriptor: target, returnID: AEReturnID(kAutoGenerateReturnID), transactionID: AETransactionID(kAnyTransactionID))
		
		event.setParamDescriptor(handler, forKeyword: AEKeyword(keyASSubroutineName))
		event.setParamDescriptor(parameters, forKeyword: AEKeyword(keyDirectObject))
		
		
		// ObjC version compares this to nil, but it is non optional!
		let descriptor = script.executeAppleEvent(event, error: &errors)
	}