Update @FocusState in UIHostingConfiguration

Question

I'm working with new feature in iOS 16: UIHostingConfiguration. In a content view I put a TextField. I try to manage the TextField's focus. To do that, I've created a @FocusState var. Unfortunately, I can't update .wrappedValue - the wrapped value always is false. Here's my code:

Cell:

cell.configurationUpdateHandler = { [self] (cell, state) in
      cell.contentConfiguration = UIHostingConfiguration {
          TaskView(task: task, shouldFocus: focusedTask == task)
      }
}

View:

struct TaskView: View {

@ObservedObject var task: Task
@FocusState var shouldFocus: Bool

init(task: Task, shouldFocus: Bool) {
    self.task = task
    self.$shouldFocus.wrappedValue = shouldFocus
    print($shouldFocus)
}

var body: some View {
    
   HStack() {
       
       Button("END") {
           $shouldFocus.wrappedValue = false
       }
       
        TextField("Task", text: $task.title)
           .focused($shouldFocus)
        }

    }
}

user_12299030 · Answer

The FocusState does not work that way, it is like State but does not have init with initial value, so possible approach is as follows:

struct TaskView: View {
    @ObservedObject var task: Task

    var shouldFocus: Bool                   // << interface
    @FocusState private var inFocus: Bool   // << internal 

    init(task: Task, shouldFocus: Bool) {
        self.task = task
        self.shouldFocus = shouldFocus
    }

    var body: some View {

        HStack() {

            Button("END") {
                inFocus = false
            }

            TextField("Task", text: $task.title)
                .focused($inFocus)
        }
        .onAppear {
            self.inFocus = shouldFocus  // << here !!
        }
    }
}

Update @FocusState in UIHostingConfiguration

1 Answers