SwiftUI default focus on TextField/TextEditor when view is loaded

I also wasn't able to get it to work using init, however I'm not really surprised by that given how other property wrappers like @State work.

I was eventually able to get it working using onAppear, however after a bunch of testing I found that I'm able to get it work with simple Views but as the view gets more complex the behavior gets confusing/inconsistent. For example I have included the code for a View below that:

• Will set the focus state that will focus a field when the view appears.
• Will not set the focus state if you you uncomment the NavigationView.
• Will set the focus state if it is the destination of a NavigationLink inside a NavigationView.
• Will not set the focus state if you follow a NavigationLink inside the view then go back.

I'm not sure what the intended behavior is, however I'm guessing that this isn't it.

Here is my sample View:

struct ComposeView: View {
  enum FocusField: Hashable {
    case field
  }

  @FocusState private var focusedField: FocusField?

  @State var text: String = ""

  var body: some View {
    //NavigationView {
      VStack {
        TextField("textField", text: $text)
          .focused($focusedField, equals: .field)
          .onAppear {
            self.focusedField = .field
        }
      }
    //}
  }

Noticed that for macOS there's a prefersDefaultFocus(_:in:). Which combined with some of the WWDC notes from Javier over here https://www.swiftui-lab.com/random-lessons#focus-2 leads me think that directly twiddling FocusState to set the default focus is seen as an anti-pattern.

However, until prefersDefaultFocus (or similar) arrives on iOS I've found that it can be made to work by adding a (hacky) small delay to setting it after onAppear gets executed, e.g. something like this ...

.onAppear {
      DispatchQueue.main.asyncAfter(deadline: .now() + 1) {  /// Anything over 0.5 seems to work
            self.focusedField = .field
       }
}

Use .task to assign the initial focused field instead of using .onAppear

TextField("Placeholder", text: $text)
          .focused($focusedField, equals: .field)
          .task {
            self.focusedField = .field
          }

I filed an FB about this if anyone else wants to refer to it: FB9676178

You should have some delay.

@avitzur, where do you put that call in the view? I have tried it in .onAppear (and .task) on my NavigationView and then my app crashes. Any hints?

Updated

I added

.onAppear() {

                            DispatchQueue.main.asyncAfter(deadline: .now() + 0.5){ nameIsFocused = true }

                        } on my TextField, and now it works. Thank you avitzur

Thank you, that is very helpful.