Swift - Update List from different View - ios

Question

I have 2 Views in my Swift Project and when I click on the Button on the secondView, I want to update the List in the First View. I don't know how to do it! If I use a static variable in my MainView and then edit this variable from the secondView, it works, but it won't update. And if I don't use static and instead use #State, it would update, but I can't access it from my secondView.
Here is the Code below:
import SwiftUI
struct ContentView: View {
var body: some View {
TabView {
MainView()
.tabItem() {
VStack {
Image(systemName: "circle.fill")
Text("MainView")
}
}.tag(0)
UpdateOtherViewFromHere()
.tabItem() {
VStack {
Image(systemName: "circle.fill")
Text("SecondView")
}
}.tag(1)
}
}
}
struct MainView: View {
var arrayList: [CreateListItems] = []
init() {
let a = CreateListItems(name: "First Name!")
let b = CreateListItems(name: "Second Name!")
let c = CreateListItems(name: "Third Name!")
arrayList.append(a)
arrayList.append(b)
arrayList.append(c)
}
var body: some View {
return VStack {
ZStack {
NavigationView {
List {
ForEach(arrayList) { x in
Text("\(x.name)")
}
}.navigationBarTitle("Main View")
}
}
}
}
}
struct UpdateOtherViewFromHere: View {
func updateList() {
//Code that should remove "FirstName" from the List in MainView
}
var body: some View {
return VStack {
Button(action: {
updateList()
}) {
Image(systemName: "heart.slash")
.font(.largeTitle)
Text("Click Me!")
}
}
}
}
struct CreateListItems: Identifiable {
var id: UUID = UUID()
var name: String
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}

Answer 1

You can share it using #State and #Binding if you put
struct ContentView: View {
#State var arrayList: [CreateListItems] = []
struct MainView: View {
#Binding var arrayList: [CreateListItems]
struct UpdateOtherViewFromHere: View {
#Binding var arrayList: [CreateListItems]
or you use the MVVM pattern and store the list in an ObservableObject and use #StateObject/#ObservedObject (source) and use #EnvironmentObject(connection) to share it between your Views.
https://developer.apple.com/documentation/swiftui/managing-model-data-in-your-app
class ParentViewModel: ObservableObject{
#Published var arrayList: [CreateListItems] = []
init(){
addSamples()
}
func addSamples() {
let a = CreateListItems(name: "First Name!")
let b = CreateListItems(name: "Second Name!")
let c = CreateListItems(name: "Third Name!")
arrayList.append(a)
arrayList.append(b)
arrayList.append(c)
}
func updateList() {
let a = CreateListItems(name: "\(arrayList.count + 1) Name!")
arrayList.append(a)
}
}
struct ParentView: View {
#StateObject var vm: ParentViewModel = ParentViewModel()
var body: some View {
TabView {
MainView().environmentObject(vm)
.tabItem() {
VStack {
Image(systemName: "circle.fill")
Text("MainView")
}
}.tag(0)
UpdateOtherViewFromHere().environmentObject(vm)
.tabItem() {
VStack {
Image(systemName: "circle.fill")
Text("SecondView")
}
}.tag(1)
}
}
}
struct MainView: View {
#EnvironmentObject var vm: ParentViewModel
var body: some View {
return VStack {
ZStack {
NavigationView {
List {
ForEach(vm.arrayList) { x in
Text(x.name)
}
}.navigationBarTitle("Main View")
}
}
}
}
}
struct UpdateOtherViewFromHere: View {
#EnvironmentObject var vm: ParentViewModel
var body: some View {
return VStack {
Button(action: {
vm.updateList()
}) {
Image(systemName: "heart.slash")
.font(.largeTitle)
Text("Click Me!")
}
}
}
}