SwiftUI List not updating after Data change. (Needs switching the view)

Question

I'm trying to change the SwiftUI list to update after tapping the checkbox button in my list. When I tap on a list row checkbox button, I call a function to set the immediate rows as checked which ID is less then the selected one. I could modify the ArrayList as selected = 0 to selected = 1. But as my list is Published var it should emit the change to my list view. but it doesn't.

Here's what I've done:

// ViewModel

import Foundation
import Combine

class BillingViewModel: ObservableObject {
    
    @Published var invoiceList = [InvoiceModel](){
        didSet {
            self.didChange.send(true)
        }
    }
    
    @Published var shouldShow = true
    
    let didChange = PassthroughSubject<Bool, Never>()
    
    init() {
        setValues()
    }
    
    func setValues() {
        for i in 0...10 {
            invoiceList.append(InvoiceModel(ispID: 100+i, selected: 0, invoiceNo: "Invoice No: \(100+i)"))
        }
    }
    
    func getCombinedBalance(ispID: Int) {
        DispatchQueue.main.async {
            
            if let row = self.invoiceList.firstIndex(where: {$0.ispID == ispID}) {
                self.changeSelection(row: row)
            }
            
        }
    }
    
    func changeSelection(row: Int) {
        if invoiceList[row].selected == 0 {
            
            let selectedRows = invoiceList.map({ $0.ispID ?? 0 <= invoiceList[row].ispID ?? 0 })
            
            print(selectedRows)
            
            for index in 0..<invoiceList.count {
                if selectedRows[index] {
                    invoiceList[index].selected = 1
                } else {
                    invoiceList[index].selected = 0
                }
            }
            
        } else {
            
            let selectedRows = invoiceList.map({ $0.ispID ?? 0 <= invoiceList[row].ispID ?? 0 })
            
            print(selectedRows)
            
            for index in 0..<invoiceList.count {
                if selectedRows[index] {
                    invoiceList[index].selected = 1

                } else {
                    invoiceList[index].selected = 0
                }
            }
        }
    }
    
}

// List View

import SwiftUI

struct ContentView: View {
    
    @StateObject var billingViewModel = BillingViewModel()
    @State var shouldShow = true
    
    var body: some View {
        NavigationView {
            ZStack {
                VStack {
                    List {
                        ForEach(billingViewModel.invoiceList) { invoice in
                            NavigationLink(
                                destination: InvoiceDetailsView(billingViewModel: billingViewModel)) {
                                invoiceRowView(billingViewModel: billingViewModel, invoice: invoice)
                            }
                        }
                        
                    }
                }
            }.navigationBarTitle(Text("Invoice List"))
        }
        
    }
}

// Invoice Row View

import SwiftUI

struct invoiceRowView: View {
    
    @StateObject var billingViewModel: BillingViewModel
    @State var invoice: InvoiceModel
    
    var body: some View {
        VStack(alignment: .leading) {
            HStack {
                Button(action: {
                    if invoice.selected == 0 {
                        print(invoice)
                        billingViewModel.getCombinedBalance(ispID: invoice.ispID ?? 0)
                    } else {
                        print(invoice)
                        billingViewModel.getCombinedBalance(ispID: invoice.ispID ?? 0)
                    }
                }, label: {
                    Image(systemName: invoice.selected == 0 ? "checkmark.circle" : "checkmark.circle.fill")
                        .resizable()
                        .frame(width: 32, height: 32, alignment: .center)
                    
                }).buttonStyle(PlainButtonStyle())
                
                Text(invoice.invoiceNo ?? "Hello, World!").padding()
                
                Spacer()
            }
        }
    }
}

// Data Model

import Foundation

struct InvoiceModel: Codable, Identifiable {
    var id = UUID()
    var ispID: Int?
    var selected: Int?
    var invoiceNo: String?
}

Answer 1

You need to use binding instead of externally injected state (which is set just to copy of value), i.e.

struct invoiceRowView: View {
    
    @StateObject var billingViewModel: BillingViewModel
    @Binding var invoice: InvoiceModel

    // .. other code

and thus inject binding in parent view

ForEach(billingViewModel.invoiceList.indices, id: \.self) { index in
    NavigationLink(
        destination: InvoiceDetailsView(billingViewModel: billingViewModel)) {
        invoiceRowView(billingViewModel: billingViewModel, invoice: $billingViewModel.invoiceList[index])
    }
}