How to make subsequent push notifications silent?

Question

There is an option in iOS settings that controls whether a push-notification will alarm a user with a sound/vibration once a notification is received. However, is it possible (via the code) to set that just first received notification from the app shall force the iPhone to play a sound / vibrate while the subsequent ones shall not?

Answer 1

You have to handle this server side: If you sent a push notification to a specific user less than x seconds ago, do not include the sound field in your new push notification's payload.
It's as simple as that.