How to use a function in another swift file that contains CoreData related properties? - core-data

Question

clueless beginner here. Apologies if my question is formed poorly. This is the first time I ask a question of this scale and I have a hard time balancing between posting too much code for the good samaritans to read and too little to post an effective question. Huge thanks in advance!
I am trying to incorporate the textfieldalert in this post in my learner project. There are two Swift files in questions: File A (PosTextFieldAlertView) has an extension that needs to use two functions in File B (ListView).
These are the functions I need to use in File A.
func addPositive(){
let newPositive = PositiveEntity(context: viewContext)
newPositive.title = alertInput
save()
}
func save() {
do { try viewContext.save() } catch { print(error) }
}
I thought of/researched two methods: 1) duplicate the function in File A or 2) create instance of the view in File B that contains that functions according this post. However I ran into problems in both methods.
Duplicating the functions:
I copied the CoreData related properties in the PosTextFieldAlert struct. But now PosTextFieldAlert in the return part of the extension has the error of "Missing arguments for parameters [Core Data properties] in call". I don’t know how to set the property in the extension without referring or creating a different sets of Core Data entities.
Creating an instance of the relevant view
In the instance creation I would need to input the arguments but I don’t know how to refer to the same NSManagedObjectContext.
Code excerpts:
PosTextFieldAlertView
struct PosTextFieldAlert<Presenting>: View where Presenting: View {
var viewContext: NSManagedObjectContext
var positives: [PositiveEntity]
var targets: [TargetEntity]
#State private var alertInput = ""
// let listView = ListView(viewContext: NSManagedObjectContext, positives: PositiveEntity, negatives: NegativeEntity, targets: TargetEntity)
#Binding var isShowing: Bool
#Binding var text: String
let presenting: Presenting
let title: String
var body: some View {
GeometryReader { (deviceSize: GeometryProxy) in
ZStack {
self.presenting
.disabled(isShowing)
VStack {
Text(self.title)
TextField(self.title, text: self.$text)
Divider()
VStack{
HStack {
Button(action: {
withAnimation {
self.isShowing.toggle()
}
}) {
Text("+")
}.padding()
Button(action: {
withAnimation {
self.isShowing.toggle()
}
}) {
Text("-")
}.padding()
}
Button(action: {
withAnimation {
self.isShowing.toggle()
}
}) {
Text("Done")
}
}
}
.padding()
.background(Color.white)
.frame(
width: deviceSize.size.width*0.7,
height: deviceSize.size.height*0.7
)
.shadow(radius: 1)
.opacity(self.isShowing ? 1 : 0)
}
}
}
func addPositive(){
let newPositive = PositiveEntity(context: viewContext)
newPositive.title = alertInput
save()
}
func save() {
do { try viewContext.save() } catch { print(error) }
}
}
extension View {
func posTextFieldAlert(isShowing: Binding<Bool>,
text: Binding<String>,
title: String) -> some View {
PosTextFieldAlert(isShowing: isShowing,
text: text,
presenting: self,
title: title)
}
}
The code in ListView
struct ListView: View {
var viewContext: NSManagedObjectContext
var positives: [PositiveEntity]
var negatives: [NegativeEntity]
var targets: [TargetEntity]
//[layout of the project]
}
The Fetchrequests in ContentView:
#Environment(\.managedObjectContext) var viewContext
#FetchRequest(sortDescriptors: []) var targets: FetchedResults<TargetEntity>
#FetchRequest(sortDescriptors: []) var positives: FetchedResults<PositiveEntity>
#FetchRequest(sortDescriptors: []) var negatives: FetchedResults<NegativeEntity>