Cannot use instance member 'dateType' within property initializer; property initializers run before 'self' is available

Question

Created Jul ’21

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I'm quite new to SwiftUI and can't get around this error. I'm trying to use two @State variables (isGlobal and dataType) in another array within the same initializer.

I keep getting the error: "Cannot use instance member 'dateType' within property initializer; property initializers run before 'self' is available" and "Cannot use instance member 'isGlobal' within property initializer; property initializers run before 'self' is available"

This is the code at the beginning of the view:

struct Home : View {
@State var dateType : Int
@State var isGlobal = true

@State var dailyVax = [
    
    DailyVaccinations(day: "\(showData(tabType: isGlobal, date: dateType, dataType: 4, change: false, dayCt: 6))", value: "\(showData(tabType: isGlobal, date: dateType, dataType: 4, change: true, dayCt: 6))", show: true),
    DailyVaccinations(day: "\(showData(tabType: isGlobal, date: dateType, dataType: 4, change: false, dayCt: 5))", value: "\(showData(tabType: isGlobal, date: dateType, dataType: 4, change: true, dayCt: 5))", show: false),
    DailyVaccinations(day: "\(showData(tabType: isGlobal, date: dateType, dataType: 4, change: false, dayCt: 4))", value: "\(showData(tabType: isGlobal, date: dateType, dataType: 4, change: true, dayCt: 4))", show: false),
    DailyVaccinations(day: "\(showData(tabType: isGlobal, date: dateType, dataType: 4, change: false, dayCt: 3))", value: "\(showData(tabType: isGlobal, date: dateType, dataType: 4, change: true, dayCt: 3))", show: false),
    DailyVaccinations(day: "\(showData(tabType: isGlobal, date: dateType, dataType: 4, change: false, dayCt: 2))", value: "\(showData(tabType: isGlobal, date: dateType, dataType: 4, change: true, dayCt: 2))", show: false),
    DailyVaccinations(day: "\(showData(tabType: isGlobal, date: dateType, dataType: 4, change: false, dayCt: 1))", value: "\(showData(tabType: isGlobal, date: dateType, dataType: 4, change: true, dayCt: 1))", show: false),
    DailyVaccinations(day: "\(showData(tabType: isGlobal, date: dateType, dataType: 4, change: false, dayCt: 0))", value: "\(showData(tabType: isGlobal, date: dateType, dataType: 4, change: true, dayCt: 0))", show: false),
]

var body: some View { ...

Here's the [DailyVaccinations] struct:

struct DailyVaccinations : Identifiable {
var id = UUID().uuidString
var day : String
var value : String
var show : Bool

}

And here's the code that actually uses the "dailyVax" array:

ForEach(dailyVax.indices,id: \.self){i in
                        
                        
                        GraphView(data: dailyVax[i], allData: dailyVax)
                            .onTapGesture {
                            
                                withAnimation{
                                    
                                    for index in 0..<dailyVax.count{
                                        dailyVax[index].show = false
                                    }
                                    dailyVax[i].show.toggle()
                                }
                                
                            }
                        
                        if dailyVax[i].value != dailyVax.last!.value {
                            Spacer(minLength: 0)
                        }
                        
                    } ...

If anyone can help me solve this issue it would be greatly appreciated! thank you

Boost

Answer 1

OOPer OP

Jul ’21

As the error message is clearly stating, you cannot use other instance properties inside an initializer of an instance property. One possible solution would be initializing the property dailyVax inside onAppear of your View.

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