Does code at 04:41 compile?

Question

The code for @State doesn't seem to work.

struct DonutListView: View {
    var donutList: DonutList
    @State private var donutToAdd: Donut?

    var body: some View {
        List(donutList.donuts) { DonutView(donut: $0) }
        Button("Add Donut") { donutToAdd = Donut() }
            .sheet(item: $donutToAdd) { // <-- would need a "donut in"
                TextField("Name", text: $donutToAdd.name) // <-- donutToAdd is optional and I'm not sure how it would be unwrapped
                Button("Save") {
                    donutList.donuts.append(donutToAdd)
                    donutToAdd = nil
                }
                Button("Cancel") { donutToAdd = nil }
            }
    }
}

Does anyone have a fix for this?

Thanks, Dan!

546

Posted by

dan101

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Answer 1

I wish Apple would test their code before presenting at a conference.
I added a name state variable for the TextField.


@State private var name: String = ""
...
            .sheet(item: $donutToAdd) { _ in
                TextField("Name", text: $name)
                .padding(10)
                .overlay(
                    RoundedRectangle(cornerRadius: 20)
                        .stroke(Color.black)
                )
                Button("Save") {
                    if let donutToAdd {
                        donutToAdd.name = name
                        donutList.donuts.append(donutToAdd )
                        self.donutToAdd = nil
                        self.name = ""
                    }
                }
                Button("Cancel") { self.donutToAdd = nil }
            }

code-block

And DonutList needs to be a class (else you get a mutating member on immutable value).

@Observable
    class DonutList {
        var donuts: [Donut]
        
        init(donuts: [Donut]) {
            self.donuts = donuts
        }
    }
code-block

Posted by

William NYC

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Does code at 04:41 compile?

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