ViewBuilder transforms

SwiftUI ⟩ Views ⟩ ViewBuilder ⟩

💈if...else

// ⭐️ if ... else
struct ContentView: View {
    var body: some View {
        // _ConditionalContent<Text, Text>
        if true { A } else { B }
    }
}

💈switch

// ⭐️ switch
struct ContentView: View {
    var index: Int
    var body: some View {
    
        // _ConditionalContent<
        //   _ConditionalContent<Text, Image>, 
        //   _ConditionalContent<Color, Rectangle>
        // >
        switch index {
            case 1: Text("hello")
            case 2: Image(systemName: "folder")
            case 3: Color.pink
            default: Rectangle()
        }
        
    }
}

👥 相關

• some (opaque type)

• ViewModifier modifies views too.

📗 參考

• Sundell ⟩ Opaque return types in Swift

• objc.io ⟩ Why Conditional View Modifiers are a Bad Idea