Should arriving GCM messages be displayed by Android?

The problem is that my GCM message arrives at my app but is not (automatically) displayed on screen.

07-06 21:33:11.525 11269-11269/com.example.myapp D/ActivityThread: BDC-Calling onReceive: intent=Intent { act=com.google.android.c2dm.intent.RECEIVE flg=0x10000010 pkg=com.example.myapp cmp=com.example.myapp/com.google.android.gms.gcm.GcmReceiver (has extras) }, receiver=com.google.android.gms.gcm.GcmReceiver@3a59595e
07-06 21:33:11.534 11269-11269/com.example.myapp D/ActivityThread: BDC-RECEIVER handled : 0 / ReceiverData{intent=Intent { act=com.google.android.c2dm.intent.RECEIVE flg=0x10000010 pkg=com.example.myapp (has extras) } packageName=com.example.myapp resultCode=-1 resultData=null resultExtras=null}
07-06 21:33:11.539 11269-11269/com.example.myapp D/ActivityThread: SVC-Calling onStartCommand: com.example.myapp.MyGcmListenerService@bc04a0c, flags=0, startId=1
07-06 21:33:11.539 11269-11269/com.example.myapp D/ActivityThread: SVC-Creating service: CreateServiceData{token=android.os.BinderProxy@df9e13f className=com.example.myapp.MyGcmListenerService packageName=com.example.myapp intent=null}
07-06 21:33:11.539 11269-11269/com.example.myapp D/ActivityThread: SVC-CREATE_SERVICE handled : 0 / CreateServiceData{token=android.os.BinderProxy@df9e13f className=com.example.myapp.MyGcmListenerService packageName=com.example.myapp intent=null}
07-06 21:33:11.543 11269-11269/com.example.myapp D/ActivityThread: SVC-SERVICE_ARGS handled : 0 / ServiceArgsData{token=android.os.BinderProxy@df9e13f startId=1 args=Intent { act=com.google.android.c2dm.intent.RECEIVE flg=0x10000010 pkg=com.example.myapp (has extras) }}07-06 21:33:11.565 11269-11269/com.example.myapp D/ActivityThread: SVC-Destroying service: com.example.myapp.MyGcmListenerService@bc04a0c
07-06 21:33:11.565 11269-11269/com.example.myapp D/ActivityThread: SVC-STOP_SERVICE handled : 0 / android.os.BinderProxy@df9e13f
07-07 21:33:11.564 11269-11530/com.example.myapp D/MyGcmListenerService: bundle: Bundle[{key1=message1, key2=message2, notification=Bundle[{e=1, body=This is a notification that will be displayed ASAP., icon=ic_launcher, title=Hello, World}], collapse_key=com.example.myapp}]
07-06 21:33:11.564 11269-11530/com.example.myapp D/MyGcmListenerService: From: 28REDACTED98
07-06 21:33:11.564 11269-11530/com.example.myapp D/MyGcmListenerService: Message: null

My receiving code is:

public class MyGcmListenerService extends GcmListenerService { public static final String TAG = MyGcmListenerService.class.getSimpleName(); @Override public void onMessageReceived(String from, Bundle data) { Log.d(TAG, "bundle: " + data); String message = data.getString("message"); Log.d(TAG, "From: " + from); Log.d(TAG, "Message: " + message); ...

The sending code (using node-gcm) is:

 var message = new ngcm.Message({ priority: 'high', contentAvailable: true, restrictedPackageName: "com.example.myapp", data: { key1: 'message1', key2: 'message2' }, notification: { title: "Hello, World", icon: "ic_launcher", body: "This is a notification that will be displayed ASAP." } });

I have tried with and without contentAvaailable and restrictedPackage but they make no difference.

My questions are:

1. Should my receiving code need to create the on-screen notification when a message arrives, or should this (as I believe) be done for me by Android?
2. The sample code says that the bundle should include a data.getString("message"); but my app sees this as null. Why?