Get notified about new requests

I need to detect when a logged in user gets a new friend request.

What would be the proper way to do this? Should I send a request to the server every minute or is there a smarter way?

Both Firebase and IonicDB offer realtime database as a service. You can subscribe to an Observable at the database and be notified when a new value is emitted. If you’re not familiar with Observables, you might want to start reading up on RxJs.

Another option would be a push notification triggered by your backend that informs your app about the new friend request. (Push notifications don’t have to display anything but can also be used as “messages” to your app)