How to use UserDefault on an Array in SwiftUI - swiftui

Question

I'm working on a checklist app that has several arrays with checks. I'd like to save the state if a users closes/quits the app. I was thinking of using the UserDefault methods for this:
HStack {
ForEach(0 ..< checklist.steps) { index in
VStack {
Button(action: {
self.checked[index].toggle()
UserDefaults.standard.set(self.checked[index], forKey: "Check")
I'm currently using the following state for checks:
#State private var checked = [false, false, false, false, false, false]
Does anyone know how to apply UserDefaults for arrays or generally how to save the state for your app when closing it?
Thanks in advance!

Answer 1

try this: (it is the code from last time ;)) i think the true/false settings itself is not correct, but the saving / loading works ;)
struct ChecklistView: View {
var checklist: Checklist
#State var currentProgress: Float = 0.0
#State var checked : [Bool] = [false, false, false, false]
init(checklist: Checklist) {
self.checklist = checklist
}
func saveUserDefaults() {
var value = ""
for eachValue in checked {
if eachValue == true { value += "1" }
else { value += "0" }
}
UserDefaults.standard.set(value, forKey: checklist.title)
}
var body: some View {
ZStack(alignment: .leading) {
// RoundedRectangle(cornerRadius: 20)
// .foregroundColor(.red).opacity(0.5)
// .frame(width: 200)
VStack {
HStack(alignment: .top) {
checklist.image
.resizable()
.aspectRatio(contentMode: .fit)
.frame(width: 40, height: 40)
.padding(.trailing)
VStack(alignment: .leading) {
Text(checklist.title)
.font(.system(size: 16, weight: .medium))
.padding(.bottom, 4)
Text(checklist.instruction.uppercased()).font(.system(size: 12))
HStack {
ForEach(0 ..< checklist.steps) { index in
VStack {
Button(action: {
self.checked[index].toggle()
print(self.checked)
self.saveUserDefaults()
}) {
ZStack {
RoundedRectangle(cornerRadius: 8)
.foregroundColor(self.checked[index] ? Color("LightGreen") : .gray )
.frame(width: 40, height: 40)
Image(systemName: self.checked[index] ? "checkmark" : "plus")
.resizable()
.aspectRatio(contentMode: .fit)
.frame(width: 16, height: 16)
.foregroundColor(self.checked[index] ? .white : .white)
}
}
}
}
}
}
}.frame(width: 350, alignment: .leading)
}
}
.onAppear() {
if let values = UserDefaults.standard.value(forKey: self.checklist.title) as? String {
self.checked = values.map {
if $0 == "1" { return true }
return false
}
}
print(self.checked)
}
.frame(width: 350)
.padding(.bottom, 16)
.cornerRadius(8)
.padding(.top, 20)
}
}

Answer 2

I haven't test that solution, but can't you store your array in your NSUserdefaults after every button action?
Button(action: {
self.checked[index].toggle()
UserDefaults.standard.set(self.checked, forKey: "Check")
Probably, the best solution would be using CoreData for that, which would be very easier to use.
PS: I can test that solution later on.. not at my Mac right now