Why is my SwiftUI view not updating when the model changes - swift

Question

How do I update the content of an existing row in a List?
The print statement shows that the button is updating the Bool, but the View does not update .
the content (button) moves as expected, but the action and formating does not change as expected.
the code for the page I am using:
struct NotificationView: View {
#ObservedObject var notificationVModel: NotificationVModel = NotificationVModel()
var body: some View {
NavigationView{
List(notificationVModel.notificationarray,id:\.NotificationName){notificationVV in
ZStack {
if notificationVV.isShgowen {
Color (.green).opacity(0.1)
.cornerRadius(10)
}
HStack{
Button(action: {
notificationVV.changTogle()
print("\(notificationVV.isShgowen)")
}, label: {
ZStack{
Circle()
.foregroundColor(Color(red: 0 / 255, green: 175 / 255, blue: 80 / 255))
.frame(width: 50, height: 50, alignment: .center)
Image(systemName: "bell")
.frame(width: 40, height: 40, alignment: .center)
.foregroundColor(.white)
} })
VStack{
HStack {
if notificationVV.isShgowen{
Text("true")
.font(.custom("AvenirNext-DemiBold", size: 10))
}
Text(notificationVV.NotificationName)
.font(.custom("AvenirNext-DemiBold", size: 20))
Spacer()
Text(notificationVV.NotifivationDate)
.font(.custom("AvenirNext-Medium", size: 12))
.foregroundColor(.gray)
}.padding(.leading).padding(.trailing)
Text(notificationVV.NotificationDiscrip)
.font(.custom("AvenirNext-Regular", size: 11))
.lineLimit(nil)
.padding(.leading).padding(.trailing)
}
}.padding()
}
}
.navigationTitle("Notification")
.navigationBarTitleDisplayMode(.inline)
}
}
}
The ViewModel
class NotificationVModel: ObservableObject {
#Published var notificationarray : [NotificationV] = [
NotificationV(NotificationName: "Notification 1", NotificationDiscrip: "Lorem ipsum dolor sit amet,consec tetur adipiscing elit Lorem ipsum doloramet,consec tetur adipiscing elit sit ipi piscing… ", NotifivationDate: "04/02/2021", isShgowen: false), NotificationV(NotificationName: "Notification 2", NotificationDiscrip: "Lorem ipsum dolor sit amet,consec tetur adipiscing elit Lorem ipsum doloramet,consec tetur adipiscing elit sit ipi piscing… ", NotifivationDate: "05/03/2021", isShgowen: true),
]
}
The model
class NotificationV : ObservableObject{
let objectWillChange = ObservableObjectPublisher()
#Published var NotificationName : String = ""
#Published var NotificationDiscrip: String = ""
#Published var NotifivationDate:String = ""
#Published var isShgowen:Bool = false
init(NotificationName: String, NotificationDiscrip: String, NotifivationDate: String, isShgowen: Bool) {
self.NotificationName = NotificationName
self.NotificationDiscrip = NotificationDiscrip
self.NotifivationDate = NotifivationDate
self.isShgowen = isShgowen
}
func changTogle(){
if isShgowen == false {
isShgowen = true
}
}
}

Answer 1

Use struct rather than class for the NotificationV.
Create a new view for the buttons and send both your viewmodel and model to the new view.
Find index of model
Fore more info, read this tutorial
https://developer.apple.com/tutorials/swiftui/building-lists-and-navigation
struct NotificationView: View {
#ObservedObject var notificationVModel: NotificationVModel = NotificationVModel()
var body: some View {
NavigationView{
List(notificationVModel.notificationarray,id:\.NotificationName){notificationVV in
ZStack {
if notificationVV.isShowen {
Color (.green).opacity(0.1)
.cornerRadius(10)
}
HStack{
ToggleNotification(notifications: $notificationVModel.notificationarray, notificationV: notificationVV)
VStack{
HStack {
Text(notificationVV.isShowen ? "true": "false")
if notificationVV.isShowen {
Text("true")
.font(.custom("AvenirNext-DemiBold", size: 10))
}
Text(notificationVV.NotificationName)
.font(.custom("AvenirNext-DemiBold", size: 20))
Spacer()
Text(notificationVV.NotifivationDate)
.font(.custom("AvenirNext-Medium", size: 12))
.foregroundColor(.gray)
}.padding(.leading).padding(.trailing)
Text(notificationVV.NotificationDiscrip)
.font(.custom("AvenirNext-Regular", size: 11))
.lineLimit(nil)
.padding(.leading).padding(.trailing)
}
}.padding()
}
}
.navigationTitle("Notification")
.navigationBarTitleDisplayMode(.inline)
}
}
}
struct ToggleNotification:View {
#Binding var notifications: [NotificationV]
var notificationV: NotificationV
var index:Int? {
notifications.firstIndex { $0.NotificationName == notificationV.NotificationName}
}
var body: some View {
Button(action: {
notifications[index!].isShowen.toggle()
print("\($notifications[index!].isShowen)")
}, label: {
ZStack{
Circle()
.foregroundColor(Color(red: 0 / 255, green: 175 / 255, blue: 80 / 255))
.frame(width: 50, height: 50, alignment: .center)
Image(systemName: "bell")
.frame(width: 40, height: 40, alignment: .center)
.foregroundColor(.white)
}
})
}
}
struct NotificationV {
var NotificationName : String = ""
var NotificationDiscrip: String = ""
var NotifivationDate:String = ""
var isShowen:Bool = false
init(NotificationName: String, NotificationDiscrip: String, NotifivationDate: String, isShowen: Bool) {
self.NotificationName = NotificationName
self.NotificationDiscrip = NotificationDiscrip
self.NotifivationDate = NotifivationDate
self.isShowen = isShowen
}
}
class NotificationVModel: ObservableObject {
#Published var notificationarray : [NotificationV] = [
NotificationV(NotificationName: "Notification 1", NotificationDiscrip: "Lorem ipsum dolor sit amet,consec tetur adipiscing elit Lorem ipsum doloramet,consec tetur adipiscing elit sit ipi piscing… ", NotifivationDate: "04/02/2021", isShowen: false), NotificationV(NotificationName: "Notification 2", NotificationDiscrip: "Lorem ipsum dolor sit amet,consec tetur adipiscing elit Lorem ipsum doloramet,consec tetur adipiscing elit sit ipi piscing… ", NotifivationDate: "05/03/2021", isShowen: true),
]
}
Follow case conventions. Names of types and protocols are UpperCamelCase. Everything else is lowerCamelCase.
https://swift.org/documentation/api-design-guidelines/
Update
As of now, NotificationV must unique NotificationName. Regardless of that, NotificationV should confirms to both Identifiable, Equatable protocols and use the following in ToggleNotification
var index:Int? {
notifications.firstIndex { $0 == notificationV}
}
NotificationV
struct NotificationV: Identifiable, Equatable {
var id: UUID = UUID()
var NotificationName : String = ""
var NotificationDiscrip: String = ""
var NotifivationDate:String = ""
var isShowen:Bool = false
init(NotificationName: String, NotificationDiscrip: String, NotifivationDate: String, isShowen: Bool) {
self.NotificationName = NotificationName
self.NotificationDiscrip = NotificationDiscrip
self.NotifivationDate = NotifivationDate
self.isShowen = isShowen
}
}
Doing so you always find correct NotificationV even if they do not have unique name.