android - Is setContentIntent(PendingIntent) required in NotificationCompat.Builder?

Question

Calling :

public static void triggerTestNotification(Context ctx, String tag, int id) {
    Notification not = new NotificationCompat.Builder(ctx)
        .setContentTitle("Title").setContentText("Text")
        .setAutoCancel(true) // cancel on click
        .setSmallIcon(R.drawable.ic_launcher).build();
    NotificationManager notificationManager = (NotificationManager) ctx
        .getSystemService(Context.NOTIFICATION_SERVICE);
    notificationManager.notify(tag, id, not);
}

in onCreate() of my main activity yields :

11-17 15:58:46.198: E/AndroidRuntime(1507): FATAL EXCEPTION: main
11-17 15:58:46.198: E/AndroidRuntime(1507): java.lang.RuntimeException: Unable to start activity ComponentInfo{gr.uoa.di.monitoring.android/gr.uoa.di.monitoring.android.activities.MainActivity}: java.lang.IllegalArgumentException: contentIntent required: pkg=gr.uoa.di.monitoring.android id=0 notification=Notification(vibrate=null,sound=null,defaults=0x0,flags=0x10)
//...
11-17 15:58:46.198: E/AndroidRuntime(1507): Caused by: java.lang.IllegalArgumentException: contentIntent required: pkg=gr.uoa.di.monitoring.android id=0 notification=Notification(vibrate=null,sound=null,defaults=0x0,flags=0x10)
11-17 15:58:46.198: E/AndroidRuntime(1507):     at android.os.Parcel.readException(Parcel.java:1326)
11-17 15:58:46.198: E/AndroidRuntime(1507):     at android.os.Parcel.readException(Parcel.java:1276)
11-17 15:58:46.198: E/AndroidRuntime(1507):     at android.app.INotificationManager$Stub$Proxy.enqueueNotificationWithTag(INotificationManager.java:274)
11-17 15:58:46.198: E/AndroidRuntime(1507):     at android.app.NotificationManager.notify(NotificationManager.java:133)
11-17 15:58:46.198: E/AndroidRuntime(1507):     at gr.uoa.di.monitoring.android.C.triggerTestNotification(C.java:200)
11-17 15:58:46.198: E/AndroidRuntime(1507):     at gr.uoa.di.monitoring.android.activities.MainActivity.onCreate(MainActivity.java:44)
11-17 15:58:46.198: E/AndroidRuntime(1507):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
11-17 15:58:46.198: E/AndroidRuntime(1507):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1722)
11-17 15:58:46.198: E/AndroidRuntime(1507):     ... 11 more

Notice the contentIntent required.

However the docs could not be more clear :

Required notification contents

A Notification object must contain the following:

• A small icon, set by setSmallIcon()

• A title, set by setContentTitle()

• Detail text, set by setContentText()

Optional notification contents and settings

All other notification settings and contents are optional. To learn more about them, see the reference documentation for NotificationCompat.Builder.

This opinion is reflected in various SO answers and results in SO questions (and another one).

workaround :

final Intent emptyIntent = new Intent();
PendingIntent pi = PendingIntent.getActivity(ctx, NOT_USED,
    emptyIntent, PendingIntent.FLAG_UPDATE_CURRENT);
//...
.setContentIntent(pi).build;

But is this really needed ? Is all this situation another Android docs bug ? Is it API dependent ?

NB my target SDK is 17 and running this on a 2.3.7 phone

Answer 1

If you use a caching service like waybackmachine and you look for previous versions of the Notifications guide, you will see that the guide does tell you that the contentIntent is required.

This is reflected in the Android source as well. NotificationManagerService handles the checking of Notifications before displaying them.

In Gingerbread, as part of the enqueueNotificationInternal() method, it has this check:

if (notification.icon != 0) {
    if (notification.contentView == null) {
          throw new IllegalArgumentException("contentView required: pkg=" + pkg
                    + " id=" + id + " notification=" + notification);
    }
    if (notification.contentIntent == null) {
        throw new IllegalArgumentException("contentIntent required: pkg=" + pkg
                + " id=" + id + " notification=" + notification);
    }
}

On later Android versions, such as Ice Cream Sandwich, that check is gone:

if (notification.icon != 0) {
    if (notification.contentView == null) {
       throw new IllegalArgumentException("contentView required: pkg=" + pkg
              + " id=" + id + " notification=" + notification);
    }
}

Thus, a contentIntent is required on Gingerbread and below.