feat: added support to have navigator scoped ViewModel

[programadorthi]

ISSUES SOLVED: #155 #168 and #210

Navigator scoped screen model was added on the #233

AndroidX ViewModel has support to scoped ViewModel here

So, we are supporting scoped ViewModel in Voyager too. How it works?
Androidx has a function viewModel {} that use the local ViewModelStoreOwner so scoped ViewModel is supported by default.
By default each Screen has your own ViewModelStoreOwner that doesn't support scoped and each screen will have a unique instance.

// ScreenA
val viewModel1 = viewModel { MyViewModel() }

// ScreenB
val viewModel2 = viewModel { MyViewModel() }

To have ViewModel scoped to a Navigator and share the same instance between screens do:

// ScreenA
val viewModel = rememberNavigatorViewModel<MyViewModel>()

// ScreenB
val viewModel = rememberNavigatorViewModel<MyViewModel>()

If you have a ViewModel scoped to Activity or Fragment do:

// ScreenA
val viewModel = viewModel(viewModelStoreOwner = activityOrFragmentViewModelStoreOwner) { SharedViewModel() }

@HiltViewModel has support now to use scoped ViewModel. To have or to get scoped ViewModel just provide to hilt function a ViewModelStoreOwner

[osrl]

Any update on this PR?

[slickorange]

@programadorthi Is is possible for you to release this on your own fork? This is really a big challenge for me..

[programadorthi]

Sorry guys. I can't. You will have to wait for owners review to check and avoid breaking changes.

[renaudmathieu]

I'm really looking forward to this feature

[DevSrSouza]

I think we should move this Android ViewModel specific API to it own module. Maybe restaure previous know voyager-androidx module

[DevSrSouza]

This is not required if you remove the navigator sopced screen models

.

[osrl]

hi, are there any plans to merge this?

[DevSrSouza]

@osrl we have a experimental support for it on the new Lifecycle KMP API.

[osrl]

any idea how to inject a viewmodel using koin into this navigatorViewModel