CODEWITHSUNDEEP
swiftswiftui
yangnom
yangnom

Reputation: 247

How can I get a struct's function that updates a variable in another view also refresh that view when changed?

import SwiftUI
import Combine

struct ContentView: View {
    
    var subtract = MinusToObject()
    
    
    var body: some View {
        VStack{
            
            Text("The number is \(MyObservedObject.shared.theObservedObjectToPass)")
            Text("Minus")
                .onTapGesture {
                    subtract.subtractIt()
                }
            
            NavigationView {
                NavigationLink(destination: AnotherView()) {
                    Text("Push")
                }.navigationBarTitle(Text("Master"))
            }

            
        }
    }
}

class MyObservedObject: ObservableObject {
    static let shared = MyObservedObject()
    private init() { }
    
    @Published var theObservedObjectToPass = 6
}

struct MinusToObject {
    func subtractIt() {
        MyObservedObject.shared.theObservedObjectToPass -= 1
    }
}

When I hit the Minus to call the function of my subtract instance, I know the value changes because if I go to another View I can see the new value, but the current view doesn't update.

I think I have to put a property wrapper around var subtract = MinusToObject() (I've tried several pretty blindly) and I feel like I should put a $ somewhere for a two-way binding, but I can't figure out quite where.

Upvotes: 1

Views: 99

Answers (1)

Asperi
Asperi

Reputation: 257493

The MinusToObject is redundant. Here is way (keeping MyObservedObject shared if you want)...

struct ContentView: View {
    
    @ObservedObject private var vm = MyObservedObject.shared
    //@StateObject private var vm = MyObservedObject.shared     // << SwiftUI 2.0
    
    
    var body: some View {
        VStack{
            
            Text("The number is \(vm.theObservedObjectToPass)")
            Text("Minus")
                .onTapGesture {
                    self.vm.theObservedObjectToPass -= 1
                }
            
            NavigationView {
                NavigationLink(destination: AnotherView()) {
                    Text("Push")
                }.navigationBarTitle(Text("Master"))
            }
            
        }
    }
}

Upvotes: 1

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