CODEWITHSUNDEEP
swiftui
Chris
Chris

Reputation: 8126

list not updating after texts change

i am sure i am making something wrong, but i don't know what.

I have a small list and i update texts with a timer which i can see in the debugger which updates. But the list won't be updated...

Thank you for help.

struct ListTest: View {

    @State      var texts       : [String]

    var body: some View {
        List {
            ForEach(self.texts, id: \.self) { text in
                Text(text)
            }
        }
    }
}

struct ContentView: View {

    @State var texts = ["a"]

    var body: some View {

        ListTest(texts: self.texts)
            .onAppear() {
                Timer.scheduledTimer(withTimeInterval: 0.5, repeats: true) { (timer) in
                    self.texts.append("\(self.texts.count)")
                    print(self.texts)
                }
        }
    }
}

Upvotes: 0

Views: 33

Answers (1)

user3441734
user3441734

Reputation: 17572

remove @State property wrapper from your ListTest

struct ListTest: View {
    var texts       : [String]
    var body: some View {
        List {
            ForEach(self.texts, id: \.self) { text in
                Text(text)
            }
        }
    }
}

enter image description here

Finally, think about more "combine compatible" code

import SwiftUI
struct ListTest: View {
    var texts: [String]
    var body: some View {
        List {
            ForEach(self.texts, id: \.self) { text in
                Text(text)
            }
        }
    }
}

struct ContentView: View {
    @State var texts = ["a"]
    let tp = Timer.publish(every: 0.5, on: .main, in: .default).autoconnect()
    var body: some View {
        ListTest(texts: self.texts)
            .onReceive(tp) { (date) in
            self.texts.append("\(self.texts.count)")
        }
    }
}
struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

which is functionally equal

Upvotes: 1

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