Stop character repetition in TextField without NumberFormatter - swiftui

Question

For example in a textfield I want to be able to repeat all numbers, but user should be able to use decimal point only once. So, the user should not be able to do: "12...4" but should only be able to do it once "12.4". Any particular way to do do it? Is it possible to do it with SwiftUI without using UIKit?
import SwiftUI
import Combine
struct TipsView: View {
#State private var amount = ""
var body: some View {
NavigationView {
Form {
Section (header: Text("Amount")) {
HStack (spacing: 1) {
Text("£")
TextField("Amount", text: $amount)
.onReceive(Just(amount)) { _ in
}
}
}
}
}
}
}

Answer 1

I have used a String separator to separate the input string into two different arrays. Meaning, one array would contain values before the decimal point and the other would contain values after the decimal point.
import SwiftUI
struct DecimalView: View {
#State private var amount = ""
var body: some View {
Form {
Section(header: Text("Amount")) {
HStack {
Text("£")
TextField("Enter amount", text: $amount)
.onChange(of: amount) { _ in
let filtered = amount.filter {"0123456789.".contains($0)}
if filtered.contains(".") {
let splitted = filtered.split(separator: ".")
if splitted.count >= 2 {
let preDecimal = String(splitted[0])
let afterDecimal = String(splitted[1])
amount = "\(preDecimal).\(afterDecimal)"
}
}
}
}
}
}
}
}