observableObject is not updating the view-CodePudding

I have two Views (main and filter). For my filter view, there are Pickers that the user can choose from that will filter data that is hardcoded inside an array. In the main view, the array is being called within a for each loop that will display the data on a LazyVGrid view. However, for some reason, the view is not updating when I filter the data.

The Filter view

import SwiftUI

struct Filter: View {
@Binding  var sortIndex: Int
@ObservedObject var model: MarketDataViewModel

var sort = ["Lowest to Highest", "Highest to Lowest"]

var body: some View {
    Form {
        Section(header: Text("Filtering")){
            
            
            Picker(selection: $sortIndex, label: Text("Sort by")) {
                ForEach(0..<sort.count) {
                    Text(self.sort[$0])
                }
            }.onChange(of: sortIndex, perform: { value in
                model.data.sort(by: {$0.price < $1.price})
                print(model.data)
                print("__________________________________")
            })
        
    } .navigationBarTitle("Filters")
  }
}

The Main view

import SwiftUI

struct MarketPlace: View {

@State var sortIndex = 0
@StateObject var item = MarketDataViewModel()

var body: some View {
    NavigationView {
        VStack {
            HStack{
                NavigationLink(destination: Filter(sortIndex: $sortIndex, model: MarketDataViewModel())) {
                    Image("Filter")
                        .resizable()
                }
                Spacer()
                    .frame(width: 15)
            }

}

CodePudding user response：

here, NavigationLink(destination: Filter(sortIndex: $sortIndex, model: MarketDataViewModel())) you create a new MarketDataViewModel every time you click on it. You should have: NavigationLink(destination: Filter(sortIndex: $sortIndex, model: item)). That way you use the single source of truth, your @StateObject var item = MarketDataViewModel().