init(wrappedValue:)

Declaration

@MainActor @preconcurrency init(wrappedValue: ObjectType)

Parameters

• wrappedValue:

  An initial value for the observable object.

Discussion

Don’t call this initializer directly. Instead, declare an input to a view with the @ObservedObject attribute, and pass a value to this input when you instantiate the view. Unlike a StateObject which manages data storage, you use an observed object to refer to storage that you manage elsewhere, as in the following example:

class DataModel: ObservableObject {
    @Published var name = "Some Name"
    @Published var isEnabled = false
}

struct MyView: View {
    @StateObject private var model = DataModel()

    var body: some View {
        Text(model.name)
        MySubView(model: model)
    }
}

struct MySubView: View {
    @ObservedObject var model: DataModel

    var body: some View {
        Toggle("Enabled", isOn: $model.isEnabled)
    }
}

Explicitly calling the observed object initializer in MySubView would behave correctly, but would needlessly recreate the same observed object instance every time SwiftUI calls the view’s initializer to redraw the view.

See Also

Creating an observed object

• init(initialValue:)