How to pass Binding of @published variable in function from ObservedObject-CodePudding

I want to pass a binding of a @Published variable from within my ObservableObject to a struct so that its value can be changed inside a closure. I can't quite get it to work. Here is a simplified version of my code below:

final class OnboardingStateController: ObservableObject {
  @Published var shouldHide: Bool = false

  func go() {
    MyLogic.fooBar(
      shouldHide: shouldHide // error appears here Cannot convert value of type 'Bool' to expected argument type 'Binding<Bool>'
    )
  }
}

struct MyLogic {
  static func fooBar(shouldHide: Binding<Bool>) {
    ... SomeClass({ shouldHide.wrappedValue = true })
  }
}

How do I do this?

CodePudding user response：

Here is an alternative, Binding needs a SwiftUI View to stay updated because of its DynamicProperty conformance

import SwiftUI

struct OnboardingStateView: View {
    @StateObject var vm: OnboardingStateController = OnboardingStateController()
    var body: some View {
        VStack{
            Button("go", action: {
                vm.go()
            })
            Text(vm.shouldHide.description)
        }
    }
}
final class OnboardingStateController: ObservableObject {
    @Published var shouldHide: Bool = false
    
    func go() {
        //This uses a completion handler vs passing the `Binding`
        MyLogic.fooBar(
            shouldHide: { shouldHide in
                self.shouldHide = shouldHide
            }
        )
    }
}

struct MyLogic {
    static func fooBar(shouldHide: (Bool) -> Void) {
        let value = Bool.random() //.. SomeClass({ shouldHide.wrappedValue = true })
        shouldHide(value)
    }
}

struct OnboardingStateView_Previews: PreviewProvider {
    static var previews: some View {
        OnboardingStateView()
    }
}

CodePudding user response：

It is not really clear why do you need Binding there, but if it is really still needed there, then you can generate it on the fly, like

  func go() {
    MyLogic.fooBar(
      shouldHide: Binding(get: { self.shouldHide }, set: { self.shouldHide = $0 })
    )
  }

Note: it is simplified variant, in which self is captured, if you need to avoid it then you take into account using [weak self] in each closure.