Why .append doesn't reload swiftUI view - swiftui

Question

I have the following view hierarchy
Nurse List View > Nurse Card > Favorite button
Nurse List View
struct NurseListView: View {
#State var data: [Nurse] = []
var body: some View {
List {
ForEach(data.indices, id: \.self) { index in
NurseCard(data: self.$data[index])
}
}
}
}
Nurse Card
struct NurseCard: View {
#Binding var data: Nurse
var body: some View {
FavoriteActionView(data:
Binding(
get: { self.data },
set: { self.data = $0 as! Nurse }
)
)
}
}
Favorite Action View
struct FavoriteActionView: View {
#Binding var data: FavoritableData
var body: some View {
Button(action: {
self.toggleFavIcon()
}) {
VStack {
Image(data.isFavorite ? "fav-icon" : "not-fav-icon")
Text(String(data.likes.count))
}
}
}
private func toggleFavIcon() {
if data.isFavorite {
if let index = data.likes.firstIndex(of: AppState.currentUser.uid) {
data.likes.remove(at: index)
}
} else {
data.likes.append(AppState.currentUser.uid)
}
}
}
When toggleFavIcon execute, it append/remove the user id from the likes property in data object but I can't see the change unless I go back to previous page and reopen the page. What I am missing here?

Answer 1

As Asperi wrote, using an ObservableObject would work well here. Something like this:
class FavoritableData: ObservableObject {
#Published var likes: [String] = []
#Published var isFavorite = false
}
struct FavoriteActionView: View {
#ObservedObject var data: FavoritableData
var body: some View {
Button(action: {
self.toggleFavIcon()
}) {
VStack {
Image(data.isFavorite ? "fav-icon" : "not-fav-icon")
Text(String(data.likes.count))
}
}
}
private func toggleFavIcon() {
if data.isFavorite {
if let index = data.likes.firstIndex(of: AppState.currentUser.uid) {
data.likes.remove(at: index)
}
} else {
data.likes.append(AppState.currentUser.uid)
}
}
}