Alert with binding

[randomeizer]

Created alert(item:...) method overloads for View. These allow providing an optional Bindable<Item?> value to the alert(item: ...) parameter, then providing other closures for the title, actions, and message, each passed an honest item, if it's not nil.

For example, a model:

@Observable
class FeatureModel {
  struct ConfirmDelete: Equatable {}

  var confirmDelete: ConfirmDelete?

  func deleteButtonTapped() {
    self.confirmDelete = .init()
  }
  
  func deleteConfirmButtonTapped() {
    // do deletion
    confirmDelete = nil
  }

  func deleteCancelButtonPressed() {
    confirmDelete = nil
  }
}

...and a View:

struct ContentView: View {
  @ObservedObject var model: FeatureModel

  var body: some View {
    Button("Delete Everything") {
      model.deleteButtonTapped()
    }
    List {
      // ...
    }
    .alert("Are you sure?", item: self.$model.confirmDelete) { _ in
      Button("Delete", role: .destructive) {
        model.deleteConfirmButtonTapped()
      }
      Button("Nevermind", role: .cancel) {
        model.deleteCancelButtonPressed()
      }
    } message: { _ in
      Text("Deleting this item cannot be undone.")
    }
  }
}

[randomeizer]

Feedback wanted, particularly on:

Parameter Order

Should title or item go first? I've split the difference, trying to follow established order in existing overloads. Basically:

1. If title is a closure, item goes first, then title, then the rest.
2. If title is a String/LocalizableStringKey, then that goes first, then item, then the rest.

This applies across the alert and confirmationDialog overloads.

isPresent()

Currently, I've deprecated the old read-only isPresent() function in SwiftUINavigation for older versions, and added a new read/write isPresent() in SwiftUINavigationCore, to allow access from TCA.

Not sure if this is the right approach, of if we should just have a new, differently-named (maybe private?) func/var for use by alert/confirmationDialog.

Thoughts?

[stephencelis]

Hey @randomeizer! Thanks for taking this on! A few comments below that should be easy to tackle, and then I think it'll be good to merge!

[randomeizer]

@stephencelis I believe I've addressed your comments. Maybe double-check the Binding migration - I wasn't 100% certain that I extracted all the relevant elements of Binding into Core, but it does compile and my app that uses this code works as expected.

[stephencelis]

Do you know why this file got deleted?

[randomeizer]

Ah, I assumed that I had added all the documentation, my bad.