SwiftUI - Subtotal TextField entries across multiple views - swiftui

Question

I have multiple views created by a ForEACH. Each View has a textfield where a user can enter a number. I would like to subtotal each entry in each view. In other words subtotal the binding in each view.
Is my approach wrong?
ForEach(someArray.allCases, id: \.id) { item in
CustomeRowView(name: item.rawValue)
}
struct CustomeRowView: View {
var name: String
#State private var amount: String = ""
var body: some View {
VStack {
HStack {
Label(name, systemImage: image)
VStack {
TextField("Amount", text: $amount)
.frame(width: UIScreen.main.bounds.width / 7)
}
}
}
}
}
Any help would be greatly appreciated.

Answer 1

there are many ways to achieve what you ask. I present here a very
simple approach, using an ObservableObject to keep the info in one place.
It has a function to add to the info dictionary fruits.
A #StateObject is created in ContentView to keep one single source of truth.
It is passed to the CustomeRowView view using #ObservedObject, and used to tally
the input of the TextField when the return key is pressed (.onSubmit).
import SwiftUI
#main
struct TestApp: App {
var body: some Scene {
WindowGroup {
ContentView()
}
}
}
class FruitCake: ObservableObject {
#Published var fruits: [String : Int] = ["apples":0,"oranges":0,"bananas":0]
// adjust for you purpose
func add(to name: String, amount: Int) {
if let k = fruits.keys.first(where: {$0 == name}),
let sum = fruits[k] {
fruits[k] = sum + amount
}
}
}
struct ContentView: View {
#StateObject var fruitCake = FruitCake()
var body: some View {
VStack {
ForEach(Array(fruitCake.fruits.keys), id: \.self) { item in
CustomeRowView(name: item, fruitCake: fruitCake)
}
}
}
}
struct CustomeRowView: View {
let name: String
#ObservedObject var fruitCake: FruitCake
#State private var amount = 0
var body: some View {
HStack {
Label(name, systemImage: "info")
TextField("Amount", value: $amount, format: .number)
.frame(width: UIScreen.main.bounds.width / 7)
.border(.red)
.onSubmit {
fruitCake.add(to: name, amount: amount)
}
// subtotal
Text("\(fruitCake.fruits[name] ?? 0)")
}
}
}