Is there any reason not to support NavigationLink that doesn't require Binding?

[kalupas226]

Hi, thank you for the wonderful library.

As the title says, I have one question.
「Is there any reason not to support NavigationLink that doesn't require Binding?」

That case seems to be common(For example, when enum holds ViewModel and uses NavigationLink), but if you have any reason not to support it, could you tell me?

Also, I found that helper in the Point-Free video episode #167 exercises.

[mbrandonw]

Hey @kalupas226, due to how property wrappers work that behavior is already available. In the destination closure you can use the argument name without the $ to access the non-binding variable.

Does that help?

[kalupas226]

Thank you for the quick reply.

Is the way you are talking about below?

// ViewModel
final class ExampleViewModel: ObservableObject {
  enum Route {
    case destination(DestinationViewModel)
  }
  // some code
}

// View
NavigationLink(
    unwrapping: $viewModel.route.case(/ExampleViewModel.Route.destination),
    destination: { $destinationViewModel in
      DestinationView(viewModel: destinationViewModel)
    },
    onNavigate: { _ in
        // ...
    },
    label: {
        // ...
    }
)

Sure. I can access the wrapped value this way.
But if I want to use only wrapped value, I want something like sheet API that does't need unwrapping binding.

.sheet(
    item: $viewModel.route.case(/ExampleViewModel.Route.destination),
    onDismiss: {
      // ...
    },
    content: { destinationViewModel in
      DestinationView(viewModel: destinationViewModel)
    }
)

Sorry for the additional question.
Thank you.

[mbrandonw]

Yeah that is what I meant, but I'm not sure what the problem is. You should be able to use .sheet like this:

.sheet(
    unwrapping: $viewModel.route,
    case: /ExampleViewModel.Route.destination,
    content: { $destinationViewModel in
      DestinationView(viewModel: destinationViewModel)
    }
)

Notice that $destinationViewModel is a binding in the closure, but destinationViewModel without the $ is just the value.

If you are having problems can you share more code?

[kalupas226]

Sorry, I was using an old SwiftLint, so the "Unused Closure Parameter Violation" warning came out.
But I realized it was my mistake. Warning disappeared after updating SwiftLint.

And I misunderstood that the API shouldn't be used when binding isn't needed.

I will use the following signatures in the future.

.sheet(
    unwrapping: $viewModel.route,
    case: /ExampleViewModel.Route.destination,
    content: { $destinationViewModel in
      DestinationView(viewModel: destinationViewModel)
    }
)

Thank you for taking the time 🙇