Update a row in a list (SwiftUI) - swift

Question

I'm an early bird in programming so I know this question can be ridiculous from the point of view of an expert but I'm stuck in this situation from several days.
I would like to update a row by using a button "Edit" (pencil) after having used another button to store the item with a TextField.
Here's the code:
class Food: Hashable, Codable, Equatable {
var id : UUID = UUID()
var name : String
init(name: String) {
self.name = name
}
static func == (lhs: Food, rhs: Food) -> Bool {
return lhs.name == rhs.name
}
func hash(into hasher: inout Hasher) {
hasher.combine(name)
}
}
class Manager: ObservableObject {
let objectWillChange = PassthroughSubject<Void, Never>()
#Published var shoppingChart: [Food] = []
init() {
let milk = Food(name: "Milk")
let coffee = Food(name: "Coffee")
shoppingChart.append(milk)
shoppingChart.append(coffee)
}
func newFood(name: String) {
let food = Food(name: name)
shoppingChart.insert(food, at: 0)
}
}
struct ContentView: View {
#ObservedObject var dm : Manager
#State var isAddFoodOpened = false
var body: some View {
VStack {
List {
ForEach(self.dm.shoppingChart, id:\.self) { food in
HStack {
Text(food.name)
Image(systemName: "pencil")
}
}
}
self.buttonAdd
}
}
var buttonAdd: some View {
Button(action: {
self.isAddFoodOpened.toggle()
}) {
Text("Add")
}
.sheet(isPresented: $isAddFoodOpened) {
Add(dm: self.dm, fieldtext: "", isAddFoodOpened: self.$isAddFoodOpened)
}
}
}
struct Add: View {
#ObservedObject var dm : Manager
#State var fieldtext : String = ""
#Binding var isAddFoodOpened : Bool
var body: some View {
VStack {
TextField("Write a food", text: $fieldtext)
buttonSave
}
}
var buttonSave : some View {
Button(action: {
self.dm.newFood(name: self.fieldtext)
self.isAddFoodOpened = false
}) {
Text("Save")
}
}
}

Answer 1

The #ObservedObject var dm : Manager object is never initialized.
Try initialized dm in ContentView like this:
#ObservedObject var dm = Manager()

Answer 2

Ok, so if I understand correctly you want to update/edit a row by using a button "Edit".
This will do it:
struct ContentView: View {
#ObservedObject var dm : Manager
#State var isAddFoodOpened = false
#State var isEditOpened = false
#State var fieldtext : String = ""
var body: some View {
VStack {
List {
ForEach(0..<self.dm.shoppingChart.count, id:\.self) { i in
HStack {
Text(self.dm.shoppingChart[i].name)
Button(action: { self.isEditOpened.toggle() }) {
Image(systemName: "pencil")
}.sheet(isPresented: self.$isEditOpened) {
TextField(self.dm.shoppingChart[i].name, text: self.$fieldtext, onEditingChanged: { _ in
self.dm.shoppingChart[i].name = self.fieldtext
})
}
}
}
}
self.buttonAdd
}
}
var buttonAdd: some View {
Button(action: {
self.isAddFoodOpened.toggle()
}) {
Text("Add")
}
.sheet(isPresented: $isAddFoodOpened) {
Add(dm: self.dm, fieldtext: "", isAddFoodOpened: self.$isAddFoodOpened)
}
}
}