Derive a UIBinding from within the observable model

[lucamegh]

I was wondering how UIBindings could be derived right from within an observable model.

@MainActor
@Observable
class FormModel {
  var name = ""
  
  var nameFieldModel: TextFieldModel {
    TextFieldModel(text: ???) // 😢
  }
}

struct TextFieldModel {
  let text: UIBinding<String>
}

You could convert the computed property into a function that takes the binding generated by the view controller.
However, it would be far better to avoid this dance altogether.

// FormModel
func nameFieldModel(name: UIBinding<String>) -> TextFieldModel {
  TextFieldModel(text: name)
}

// FormViewController
let model = model.nameFieldModel(name: $model.name)
let nameField = TextField(model: model)

Perhaps introducing UIBinding(get:set:) initializer could help.

[mbrandonw]

Hi @lucamegh, you can do this instead:

@UIBindable var model = self
TextFieldModel(text: $model.name)

Does that work for you?

Perhaps introducing UIBinding(get:set:) initializer could help.

Ideally we never have to introduce a tool like that because it destroys our ability to make bindings Hashable, which is key to how the whole system works.

[lucamegh]

I like that solution, thanks Brandon.

I'm about to open a couple more discussions on the new tools.