ios - SwiftUI if let inside View

Question

I want a if let statement inside a View.

@ObservedObject var person: Person?
 var body: some View {
      if person != nil {
        // this works
      }
      if let p = person {
        // Compiler error
      }
    }

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

Answer 1

Yes, the notation requested in code snapshot is not allowed, at least for now, but the intended result is possible to achieve with the following very simple approach - extract control flow into function:

var person: Person? // actually @ObservedObject does not allowed optional
var body: some View {
    VStack {
         if person != nil {
           // same as before
         }
         personViewIfExists() // << just extract it in helper function
    }
}

private func personViewIfExists() -> some View { // generates view conditionally
    if let p = person {
      return ExistedPersonView(person: p) // << just for demo
    }
}

on some conditions also the following variant of function might be required (although it produces the same result)

private func personViewIfExists() -> some View {
    if let p = person {
      return AnyView(ExistedPersonView(person: p))
    }
    return AnyView(EmptyView())
}