Differences in a body of view in SwiftUI

Question

I have a list of Menu

let muscleEtfs = Menu(name:"MuscleETFs",  image:"image", destination: .muscleETFs)

let menus: [Menu] = [home, marketTrend, indexes, sectors, stockAnalysis, backtest, screener, myPortfolio, watchList, muscleStocks, muscleEtfs]

My goal is to change the destination of NavigationLink in SwiftUI conditionally. Could anybody explain to me why the switch case does not work but if does.

let muscleEtfs = Menu(name:"MuscleETFs",  image:"image", destination: .muscleETFs)

    var body: some View {
        let menus: [Menu] = [home, marketTrend, indexes, sectors, stockAnalysis, backtest, screener, myPortfolio, watchList, muscleStocks, muscleEtfs]

        return List {
            ForEach(menus) { menu in

                // This does not work
                switch menu.destination {
                case .news:
                    NavigationLink(
                            destination: HomeNewsView(menu: menu)
                    )
                    {
                        Text("\(menu.name)")
                    }
                default:
                    NavigationLink(
                            destination: HomeNewsView(menu: menu)
                    )
                    {
                        Text("\(menu.name)")
                    }

                }

                // This does
                if menu.destination == .news   {
                    NavigationLink(
                            destination: HomeNewsView(menu: menu)
                    )
                    {
                        Text("\(menu.name)")
                    }
                }
            }
        }

Using switch conditions throws compile error on Xcode

Closure containing control flow statement cannot be used with function builder 'ViewBuilder'

switches returning Views are not implemented the way you want it. You can use the logic inside a method or use if/else only. — Fabian, Dec 23 '19 at 08:03
Does this answer your question? [Alternative to switch statement in SwiftUI ViewBuilder block?](https://stackoverflow.com/questions/56736466/alternative-to-switch-statement-in-swiftui-viewbuilder-block) — nayem, Dec 23 '19 at 08:04
Thanks. only this would work not View or AnyView only some view as a return type. — Nafiz, Dec 23 '19 at 08:29

score 0 · Answer 1 · answered Dec 23 '19 at 08:32

This works, remember return type AnyView or View won't work.

func destinationView(menu: Menu) -> some View {

        switch menu.destination {
        case .news:
            return NavigationLink(
                    destination: HomeNewsView(menu: menu)
            )
            {
                Text("\(menu.name)")
            }
        default:
            return NavigationLink(
                    destination: HomeNewsView(menu: menu)
            )
            {
                Text("\(menu.name)")
            }
        }

    }

Differences in a body of view in SwiftUI

1 Answers1