Should I include LifecycleOwner in ViewModel?

Question

LifecycleOwner is currently needed in order for me to create an observer.

I have code which creates an Observer in the ViewModel so I attach the LifecycleOwner when

Answer 1

Assumptions:

1. Fuel refers to your ViewModel
2. Fuel.request(IpAddressApi.MyIp()) is a method in your ViewModel
3. IpAddressApi.MyIp() does not have a reference to your LifecycleOwner,

If all are true,then you are not violating it. So long as you are not passing a LifecycleOwner reference to the ViewModel you are safe!

LifecycleOwner - relates to an Activity or Fragment as it owns the various Android Lifecycles e.g onCreate, onPause, onDestroy etc

Answer 2

No. If you wish to observe changes of some LiveData inside your ViewModel you can use observeForever() which doesn't require LifecycleOwner.

Remember to remove this observer on ViewModel's onCleared() event:

val observer = new Observer() {
  override public void onChanged(Integer integer) {
    //Do something with "integer"
  }
}

...

liveData.observeForever(observer);

...

override fun onCleared() {
    liveData.removeObserver(observer) 
    super.onCleared()
}

Very good reference with examples of observe LiveData.