Unable to apply a value to a Published Variable - swiftui

Question

I am having difficulty assign a value to a Published variable, (weeklyAllowance).
There are 4 variables in total, of which 3 are populated outside of a button action (TextFields) working as expected
The last variable (WeeklyAllowance) must get value from with the action button.
Thanks in advance
class Users: ObservableObject {
#Published var firstName = ""
#Published var lastName = ""
#Published var age = ""
#Published var weeklyAllowance = ""
}
import SwiftUI
struct ContentView: View {
#ObservedObject var myDetails = Users()
var body: some View {
NavigationView {
VStack {
TextField("Enter Firstname",text: $myDetails.firstName)
TextField("Enter Lastname",text: $myDetails.lastName)
TextField("Enter Age",text: $myDetails.age)
Text("My name is \(myDetails.firstName)")
Text("My Last name is \(myDetails.lastName)")
Text("My age is \(myDetails.age)")
//Spacer()
VStack {
//Now Update the details
TextField("Name Update",text: $myDetails.lastName)
Text("Lastname update \(myDetails.lastName)")
}
Spacer()
//Link to new view
Button(action: {
//Assign period in the
self.myDetails.objectWillChange.send()
self.myDetails.weeklyAllowance = "Weekly"
}) {
NavigationLink(destination: detailUpdate(UpdateFirstname: $myDetails.firstName, UpdateLastname: $myDetails.lastName, UpdateAge: $myDetails.age,periodWkly: $myDetails.weeklyAllowance)) {
Text("The Link")
}
}
}.padding()
}
}
}
This is a update Test
struct detailUpdate: View {
#Binding var UpdateFirstname: String
#Binding var UpdateLastname: String
#Binding var UpdateAge: String
#Binding var periodWkly : String
var body: some View {
VStack {
Text("My First Name Update is \(UpdateFirstname)")
Text("My Last Name Update is \(UpdateLastname)")
Text("My Age Update is \(UpdateAge)")
Text("This is a \(periodWkly) allowance")
}.padding()
}
}

Answer 1

In your code button does not work, but works directly a link (it does not matter that you place it in button's label - on tap activated a link, not a button).
Here is your ContentView that activates link on button click:
struct ContentView: View {
#ObservedObject var myDetails = Users()
#State private var activatedLink = false
var body: some View {
NavigationView {
VStack {
TextField("Enter Firstname",text: $myDetails.firstName)
TextField("Enter Lastname",text: $myDetails.lastName)
TextField("Enter Age",text: $myDetails.age)
Text("My name is \(myDetails.firstName)")
Text("My Last name is \(myDetails.lastName)")
Text("My age is \(myDetails.age)")
//Spacer()
VStack {
//Now Update the details
TextField("Name Update",text: $myDetails.lastName)
Text("Lastname update \(myDetails.lastName)")
}
Spacer()
//Link to new view
Button(action: {
//Assign period in the
self.myDetails.weeklyAllowance = "Weekly"
self.activatedLink = true
}) {
Text("The Link")
}
NavigationLink(destination: detailUpdate(UpdateFirstname: $myDetails.firstName, UpdateLastname: $myDetails.lastName, UpdateAge: $myDetails.age, periodWkly: $myDetails.weeklyAllowance), isActive: $activatedLink) {
EmptyView()
}
}.padding()
}
}
}

Answer 2

You may not have to embed a navigationLink inside a button. Just use it directly.
NavigationLink(destination: detailUpdate(UpdateFirstname: $myDetails.firstName, UpdateLastname: $myDetails.lastName, UpdateAge: $myDetails.age,periodWkly: $myDetails.weeklyAllowance)) {
Text("The Link")
}.onDisappear{
self.myDetails.weeklyAllowance = "Weekly"
}