Activity that passes argument to ViewModel via public setter method instead of Constructor.

UserDetailActivity.kt

const val ARGUMENT_USER_ID = "ARGUMENT_USER_ID"
  
class UserDetailActivity : AppCompatActivity() {
  
    @Inject
    internal lateinit var viewModelFactory: ViewModelProvider.Factory
    private lateinit var userDetailViewModel: UserDetailViewModel
 
    override fun onCreate(savedInstanceState: Bundle?) {
        // ...
 
        userDetailViewModel = ViewModelProviders.of(this, viewModelFactory).get(UserDetailViewModel::class.java)
        userDetailViewModel.setUserDetail(intent.getStringExtra(ARGUMENT_USER_ID))
        userDetailViewModel.getUserDetail().observe(this, Observer<UserDetailModel>{ userDetail ->
            // update UI
        })
    }
}