Submitting Values (SwiftUI)

The onSubmit view modifier (SwiftUI Release 3, iOS 15+) runs a closure when the user hits the return key in a text field, search bar, or form. It is the declarative replacement for delegate callbacks on submit.

Submit Triggers

onSubmit(of:) takes a trigger that scopes which submissions fire the closure: .search, .text, or .form. With .search the closure runs only when the user submits the search field.

struct SearchView: View {
  @ObservedObject var viewModel: ViewModel
  @Binding var query: String

  var body: some View {
    List(viewModel.messages, id: \.self) { message in
      Text(message)
    }
    .searchable(text: $query)
    .onSubmit(of: .search) {
      viewModel.search(matching: query)
    }
    .navigationTitle("Search")
  }
}

For TextField and SecureField, attach the modifier with the .text trigger. You can stack several onSubmit modifiers with different triggers on one hierarchy, each with its own closure.

Return Key Label

submitLabel changes the label of the return key on the software keyboard. SubmitLabel has predefined values: done, go, send, join, route, search, return, next, and continue.

TextField("query", text: $query)
  .submitLabel(.send)
  .onSubmit(of: .text) {
    print(query)
  }

Scopes

onSubmit can sit anywhere above the fields, so one closure can serve a whole form. Use submitScope to exclude a view from triggering that shared submission while its condition is true.

VStack {
  TextField("phone", text: $viewModel.phone)
    .submitScope(viewModel.phone.count > 11)

  VStack {
    TextField("email", text: $viewModel.email)
    TextField("password", text: $viewModel.password)
  }
}
.onSubmit(of: .text) {
  viewModel.signUp()
}

Here the phone field never fires the sign-up closure while the scope condition holds; the other fields still do.