Optional Type Date

Question

Created Jun ’22

Replies 2

Boosts 0

Views 1.9k

Participants 2

I'm sorry I know this is basic swift, but how do I get I make the selection an optional return? I know it's with ?? "" with a string, but I don't know how to do it with a date type.

Also how do I get a navigationBarTitle to work on this view? The "My Calendar" doesn't show up when I run the code.

import SwiftUI

struct ReciPrep: View {
    @State private var date: Date? = ni
    @Environment(\.calendar) var calendar
    
    @State private var showingAddView = false
    var body: some View {
        VStack{
            DatePicker("Calendar", selection: $date, in: Date.now...,displayedComponents: [.date]) //Error: Cannot convert value of type 'Binding<Date?>' to expected argument type 'Binding<Date>'
                .datePickerStyle(.graphical)
            Spacer()
        }
        .navigationBarTitle("My Calendar")
    }
}

Any help would be greatly appreciated. Have a good day!

Boost

Answer 1

WeagleWeagle OP

Jun ’22

I want date to be nil if no date is selected. How do I do that in the DatePicker?

0

Answer 2

Claude31 OP

Jun ’22

You cannot do it directly.

You should try (but I have not completed this yet) to:

create a var to hold the current date value
when picker closes (onDisappear), perform code to test if data has changed
do what you need then.

But calling .onDisappear on DatePicker is not that easy: https://stackoverflow.com/questions/66190299/swiftui-datepicker-events

If that does not work, you may try with onChange:

declare an optional date:

    @State private var newDate : Date? = nil

Call .onChange modifier on picker

        DatePicker(
            "Start Date",
            selection: $date,
            displayedComponents: [.date]
        )
            .onChange(of: date, perform: { value in
                newDate = date  // Do whatever you need then
                print("changed", value, newDate)
            })

0