how does a ViewModel provider (something like ```s...

# android

[scottiedog45]

how does a ViewModel provider (something like

singleLargeTextInputViewModel = ViewModelProviders.of(this, SingleLargeInputViewModel.FACTORY(NetworkService())).get(
            SingleLargeInputViewModel::class.java
        )

) “know” (????) that a view model already exists? Or would it?

[Adam Powell]

it fetches the ViewModelStore from the activity or fragment you gave it, which is tied into the nonConfigurationInstance mechanism of activity recreation. It just passes a map from old to new activity instance and stores viewmodels for you

[Adam Powell]

it ends up here eventually https://android.googlesource.com/platform/frameworks/support/+/refs/heads/androidx-master-dev/activity/activity/src/main/java/androidx/activity/ComponentActivity.java#268

[scottiedog45]

Oh cool! I had no idea about the nonConfigurationInstance or that viewModelStore was a thing activities/fragments had.