[SwiftUI] まだ `NavigationLink(...) { EmptyView() }` で消耗してるの？

Tl;Dr

+ EmptyLink(isActive: $isActive) {
+     ChildView()
+ }
- NavigationLink(isActive: $isActive, destination: { ChildView() }) {
-     EmptyView()
- }

How to use

struct ContentView: View {
    @State var isActive: Bool = false

    var body: some View {
        NavigationView {
            VStack {
                Button("画面遷移") { isActive = true }

                // 🎄 Readable 🎁
                EmptyLink(isActive: $isActive) {
                    ChildView()
                }

                // NavigationLink(isActive: $isActive, destination: { ChildView() }) {
                //     EmptyView()
                // }
            }
            .navigationTitle("18日目")
        }
    }
}

struct ChildView: View {
    var body: some View {
        Text("Child")
            .navigationTitle("Child")
    }
}

Source code

struct EmptyLink<Destination: View>: View {
    private var navigationLink: () -> NavigationLink<EmptyView, Destination>

    init(
        isActive: Binding<Bool>,
        @ViewBuilder destination: @escaping () -> Destination
    ) {
        navigationLink = {
            NavigationLink(
                destination: destination(),
                isActive: isActive,
                label: { EmptyView() }
            )
        }
    }

    init<V: Hashable>(
        tag: V,
        selection: Binding<V?>,
        @ViewBuilder destination: @escaping () -> Destination
    ) {
        navigationLink = {
            NavigationLink(
                tag: tag,
                selection: selection,
                destination: destination,
                label: { EmptyView() }
            )
        }
    }

    var body: some View {
        navigationLink()
    }
}

おわりに

SwiftUI Advent Calendar 2022 の19日目の記事でした 🎁

- Merry Christmas, SwiftUI Lovers -

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