What is the correct way of passing constructor arguments to compose view model using viewModel() in ...

# compose

[Shivam Sethi]

What is the correct way of passing constructor arguments to compose view model using viewModel() in a composable?

[Ian Lake]

We had talked about retrieving navigation arguments in a ViewModel just the other day: https://kotlinlang.slack.com/archives/CJLTWPH7S/p1614973600447400

[Ian Lake]

What exactly are you trying to do?

[Shivam Sethi]

I want to to pass String argument to viewmodel using viewmodel factory but the problem is in viewmodel factory when I try to return instantiated viewmodel with the String argument I have to grab the other arguments which I am directly injecting through hilt viewmodel ?

[Ian Lake]

The whole point of Dagger (and by extension, Hilt), is that all dependencies are found at compile time. The ability to add dependencies (such as your string) at runtime is called assisted injection and the only kind of @AssistedInject for ViewModels is arguments, specifically via the SavedStateHandle object, which is what that thread I linked to talks about. Here's the Hilt issue for more details: https://github.com/google/dagger/issues/2287

[Ian Lake]

So if you're using Navigation Compose and arguments there, they'll be passed to the SavedStateHandle of your ViewModel automatically, right alongside your other Hilt provided dependencies

[Shivam Sethi]

Oh, I see. thanks a lot, my mistake. I should have passed that String as navigation argument so that I can retrieve that via SaveStateHandle in viewModel .

[Ian Lake]

That would be the way to do it if you're using Hilt, yup!

[Ian Lake]

Using Hilt with Navigation Compose should be even easier later this week (if all goes according to plan): https://kotlinlang.slack.com/archives/CJLTWPH7S/p1614619457323100?thread_ts=1614601227.289300&cid=CJLTWPH7S

[Shivam Sethi]

Yes I am using hilt latest artifacts, thanks again.