Is it safe to pass context in dependency in ViewModel?

Question

I am passing SessionManager as Dependency that require context in my ViewModel

val viewModel = ViewModelProvider(this, ListingsViewModelFactory(
        ListingsModel(1),
        SessionManager(
            requireContext(), <===== HERE
            JsonEncoder(),
            JsonDecoder()),
        Validator(),
        WebService(),
        JsonEncoder(),
        JsonDecoder()
    )
    ).get(ListingsViewModel::class.java)

we know that passing context to ViewModel is a bad practice that should cause memory leaks.

1. So can we pass context in dependency in ViewModel like currently i'm passing in SessionManager ?
2. Passing context in Dependency in ViewModel cause memory leaks?

Thanks for all the answers.

Answer 1

When you call requireContext() in a Fragment, it is actually getting the Activity instance, and passing that to the ViewModel will leak the Activity.

It is safe to pass the application Context, because that is a single instance for the lifetime of your application.

So replace requireContext() with requireContext().applicationContext , and it is fine.

It seems a bit odd that you are instantiating your JsonEncoder and Decoder twice, but maybe it's OK with your logic. You might want to check that.

Answer 2

I assume it depends on the type of context. Since the lifetime of a ViewModel is longer than the lifetime of the view it refers to, passing Activity can cause memory leak.

However, the lifetime of a ViewModel cannot be longer than the lifetime of the application. So the passing of Application should be fine.