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SOLVED: SwiftData: How do I create an Add view with an optional date

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Using SwiftData I have a very basic model with an optional date:

import SwiftData

@Model
class Item {
    var name: String
    var date: Date? = nil

    init(name: String, date: Date) {
        self.name = name
        self.date = date
    }
}

I'm working on the Add view to insert data into that model and no matter what I've tried so far, I get a variety of different errors around the date field. I'm fairly certain I have to hide the date picker, since I don't think I can have it displayed with an empty value. But even then, since I'm binding data to the field, I get this error: Cannot convert value of type 'Binding<Date?>' to expected argument type 'Binding<Date>'

    @State private var newItem = Item(name: "", date: Date())

    var body: some View {

        List{
            Section("Add item"){
                TextField("Enter Name", text: $newItem.name)

                HStack{
                    Text("Select Date")
                    Spacer()
                    Image(systemName: "calendar.badge.plus")
                    if let date = $newItem.date {
                        DatePicker("Date", selection: date)
                    }
                }

I've tried a variety of alternates in the @State declaration around date with nil but those generate their own errors that 'nil' cannot be assigned to type 'Date.Type'

It seems like it's impossible to have a date field that is optional but I've seen other apps pull it off, I simply have no idea how. Any suggestions?

3      

The initializer in your Item class requires a Date as a parameter, rather than a Date?. If you change that, does that help with your problem?

3      

I think it does help, because things are starting to look right but I'm not quite all the way there yet.

I updated the init in the model

@Model
class Item {
    var name: String
    var date: Date? = nil

    init(name: String, date: Date?) {
        self.name = name
        self.date = date
    }
}

And the State to align (I think): @State private var newItem = Item(name: "", date: Date?.none)

But I'm still getting the binding error at the date picker, which I haven't changed: Cannot convert value of type 'Binding<Date?>' to expected argument type 'Binding<Date>'

3      

The reason for error is the DatePicker has init() that require a Binding Date not an optional a bit like your before you change it.

init(
    selection: Binding<Date>,
    displayedComponents: DatePicker<Label>.Components = [.hourAndMinute, .date],
    @ViewBuilder label: () -> Label
)

A few questions for you

  1. Do you really need it to be optional?, (Remember that optionals in CoreData/SwiftData are different then in Swift)
  2. How do you tell if a new item should have a date or not?

I have done a little hack to make it work. Change you init slighty to

class Item {
    var name: String
    var date: Date?

    init(name: String, date: Date? = nil) {
        self.name = name
        self.date = date
    }
}

This will give Item(name: ) and `Item(name: , date: ) in autocomplete

Add two properites to hold the new infomation

@State private var name = ""
@State private var date = Date.now

Add a property to say if a date is you be used

@State private var showingDatePicker = false

Then you can use it in the List

Section("Add item"){
  TextField("Enter Name", text: $name)

  if showingDatePicker {
      HStack{
          Image(systemName: "calendar.badge.plus")

          DatePicker("Date", selection: $date, displayedComponents: .date)
      }
  } else {
      Button {
          withAnimation {
              showingDatePicker.toggle()
          }
      } label: {
          Label("Select Date", systemImage: "calendar.badge.plus")
      }
  }
}

I have added a property for testing

@State private var items = [Item]()

Now add a funtion to change to a Item

func save() {
    let item: Item

    if showingDatePicker {
        item = Item(name: name, date: date)
    } else {
        item = Item(name: name)
    }

    // Add to array but you could save to SwiftData
    items.append(item)
}

For ease I added a Button to List view to "save" a new item but you can do what you want

Button("Add", action: save)

Lastly added a ForEach to show the items array

Section {
    ForEach(items) { item in
        HStack {
            Text(item.name)
            Spacer()
            if let date = item.date {
                Text(date, style: .date)
            }
        }
    }
}

I would serious consider seeing if I could just use non optional Date as you will also have to unwrap it every time you use it!

3      

This is the complete demo project

struct ContentView: View {
    // Added to make list work for testing
    @State private var items = [Item]()

    // Temporary properties to enter data
    @State private var name = ""
    @State private var date = Date.now

    // A property to show DataPicker if date is required
    @State private var showingDatePicker = false

    var body: some View {
        List{
            Section("Add item"){
                TextField("Enter Name", text: $name)

                if showingDatePicker {
                    HStack{
                        Image(systemName: "calendar.badge.plus")

                        DatePicker("Date", selection: $date, displayedComponents: .date)
                    }
                } else {
                    Button {
                        withAnimation {
                            showingDatePicker.toggle()
                        }
                    } label: {
                        Label("Select Date", systemImage: "calendar.badge.plus")
                    }
                }

                Button("Add", action: save)
            }

            // List to show that you adding Items with and with Date
            Section {
                ForEach(items) { item in
                    HStack {
                        Text(item.name)
                        Spacer()
                        if let date = item.date {
                            Text(date, style: .date)
                        }
                    }
                }
            }
        }
    }

    func save() {
        let item: Item

        if showingDatePicker {
            item = Item(name: name, date: date)
        } else {
            item = Item(name: name)
        }

        // Add to array but you could save to SwiftData
        items.append(item)
    }
}

#Preview {
    ContentView()
}

class Item: Identifiable {
    var id = UUID() // <- Added to make list work for testing
    var name: String
    var date: Date?

    init(name: String, date: Date? = nil) {
        self.name = name
        self.date = date
    }
}

6      

Thank you so much! Unfortunatley, I do really need it to be an optional Date for other parts of the app to work correctly. This is unbelievably helpful.

3      

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