How do I access a random value from the restaurantList each time I tap the randomize button

Question

struct RandomizeTab: View {
    
    var restaurantInfo = Restaurants()
    
    var body: some View {
        
        NavigationView {
            NavigationLink(
                destination: DetailView(restaurantInfo: restaurantInfo.restaurantList[Int.random(in: 0...restaurantInfo.restaurantList.count-1)]),
                label: {
                    Text("Randomize")
                        .font(.title3)
                        .fontWeight(.bold)
                        .padding()
                        .background(Color.red)
                        .foregroundColor(.white)
                        .clipShape(Capsule())
                })
            
        }

    }
}

Currently, this code chooses one random restaurant from the list and doesn't choose a new random restaurant from the list each time I tap it.

Arrays have a random element method – lorem ipsum Oct 13 '21 at 18:34 — lorem ipsum, Oct 13 '21 at 18:34

score 0 · Accepted Answer · answered Oct 13 '21 at 18:44

NavigationLink destinations are calculated on the first render of the view. So, your random calculation will only be called once. One solution to that is to use a NavigationLink that lazily loads the view. There's a StackOverflow answer that I've borrowed that from: (https://stackoverflow.com/a/61234030/560942)


struct ContentView : View {
    var elements = [1,2,3,4,5,6,7]
    
    var body: some View {
        NavigationView {
            NavigationLink(destination:
                            NavigationLazyView(DetailView(input: elements.randomElement()!))
            ) {
                Text("Go to random")
            }
        }
    }
}

struct NavigationLazyView<Content: View>: View {
    let build: () -> Content
    init(_ build: @autoclosure @escaping () -> Content) {
        self.build = build
    }
    var body: Content {
        build()
    }
}

struct DetailView : View {
    var input : Int
    
    var body: some View {
        Text("\(input)")
    }
}

Now, the content is calculated lazily and so the random calculation is done each time.

How do I access a random value from the restaurantList each time I tap the randomize button

1 Answers1