Missing argument for parameter 'referenceDate' in call in swift

App Development
1

My COUNTDOWNApp.swift code
where to put the date
please help and give exact instructions as i am a noob
I need to make a count down to an event

import SwiftUI

@main
struct COUNTDOWNApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
        }
    }
}

and my ContentView.swift

import SwiftUI

struct ContentView : View {
    
    @State var nowDate: Date = Date()
    let referenceDate: Date
    var timer: Timer {
        Timer.scheduledTimer(withTimeInterval: 1, repeats: true) {_ in
            self.nowDate = Date()
        }
    }
    
    var body: some View {
        Text(countDownString(from: referenceDate))
            .font(.largeTitle)
            .onAppear(perform: {
                _ = self.timer
            })
    }

    func countDownString(from date: Date) -> String {
        let calendar = Calendar(identifier: .gregorian)
        let components = calendar
            .dateComponents([.day, .hour, .minute, .second],
                            from: nowDate,
                            to: referenceDate)
        return String(format: "%02dd:%02dh:%02dm:%02ds",
                      components.day ?? 00,
                      components.hour ?? 00,
                      components.minute ?? 00,
                      components.second ?? 00)
    }

}
2

Does this kind of work for you?

struct ContentView : View {

    @State private var nowDate: Date = Date()
    @State private var referenceDate: Date = Date()
    var timer: Timer {
            Timer.scheduledTimer(withTimeInterval: 1, repeats: true) {_ in
                self.nowDate = Date()
            }
        }

    var body: some View {
        Text(countDownString(from: referenceDate))
            .font(.largeTitle)
            .onAppear(perform: {
                getReferenceDate()
                _ = self.timer
            })
    }

    func countDownString(from date: Date) -> String {
        let calendar = Calendar(identifier: .gregorian)
        let components = calendar
            .dateComponents([.day, .hour, .minute, .second],
                            from: nowDate, to: referenceDate
                            )
        return String(format: "%02dd:%02dh:%02dm:%02ds",
                      components.day ?? 00,
                      components.hour ?? 00,
                      components.minute ?? 00,
                      components.second ?? 00)
    }

    func getReferenceDate() {
        let calendar = Calendar.current
        let date = calendar.date(byAdding: .minute, value: 2, to: Date())
        referenceDate = date!
    }

}

Essentially what I have done is generate a reference date to countdown to by calling the getReferenceDate() function in .onAppear. That date is 2 minutes from the current Date.

Let me know it that’s what you are looking for.

3

lots of errors in this code

4

What errors are you getting?

5

Screenshot 2021-07-03 at 11.30.33 AM
Screenshot 2021-07-03 at 11.30.33 AM404×872 67.2 KB
Screenshot 2021-07-03 at 11.30.18 AM
Screenshot 2021-07-03 at 11.30.18 AM408×1222 83.1 KB

6

What version of Xcode are you using?

7

Version 12.5.1 (12E507)

8

Exactly the same as I have and the code works perfectly.

9

please send me the file

10

on we transfer

11

the date i need to count down to 27 july 2021

12

There should be no need for me to send you the project. The ContentView code I pasted in my reply should work for you. Either overwrite your code with this… or create a new test project and paste this into that project in place of the ContentView in that new project.

Just for exercise I adjusted the referenceDate calculation to add 24 days to the current date which would be July 27.

struct ContentView : View {

    @State private var nowDate: Date = Date()
    @State private var referenceDate: Date = Date()
    var timer: Timer {
            Timer.scheduledTimer(withTimeInterval: 1, repeats: true) {_ in
                self.nowDate = Date()
            }
        }

    var body: some View {
        Text(countDownString(from: referenceDate))
            .font(.largeTitle)
            .onAppear(perform: {
                getReferenceDate()
                _ = self.timer
            })
    }

    func countDownString(from date: Date) -> String {
        let calendar = Calendar(identifier: .gregorian)
        let components = calendar
            .dateComponents([.day, .hour, .minute, .second],
                            from: nowDate, to: referenceDate)
        return String(format: "%02dd:%02dh:%02dm:%02ds",
                      components.day ?? 00,
                      components.hour ?? 00,
                      components.minute ?? 00,
                      components.second ?? 00)
    }

    func getReferenceDate() {
        let calendar = Calendar.current
        let date = calendar.date(byAdding: .day, value: 24, to: Date())
        referenceDate = date!
    }

}
13

Screenshot 2021-07-03 at 11.44.24 AM
Screenshot 2021-07-03 at 11.44.24 AM426×1240 84.9 KB
Screenshot 2021-07-03 at 11.44.35 AM
Screenshot 2021-07-03 at 11.44.35 AM430×800 56.3 KB

14

errors

15

soory i had not put import swiftui

16

Ah yeah that would help.

17

If you specifically want to have the countdown to 27-July-2021 then the following adjustment to getReferenceDate() will work for you.

    func getReferenceDate() {
        let dateFormatter = DateFormatter()
        dateFormatter.dateFormat = "dd-MM-yyyy"
        let newDate = "27-07-2021"
        let date = dateFormatter.date(from: newDate)
        referenceDate = date!
    }
1 Like
18

A better way of doing this is as follows:

let referenceDate: Date = {
        let future = DateComponents(
            year: 2021,
            month: 7,
            day: 27,
            hour: 8
        )
        return Calendar.current.date(from: future)!
    }()

and you can remove the getReferenceDate() function.

The future date is 27, July, 2021 at 8am in the morning.