multiply two value from textfield by using core data in swiftui - core-data

Question

i try to make an invoice app by using core data, i have 4 attribute: Article String, Price String , Quantity String and Taxe String and i try to make a fonction to multiply price * quantity and the result of them i want to make another function for calculate the taxe for each article
Like this ->
Article:
Price $:
Quantity x:
Taxe %:
Total taxe %:
Total price taxe incl $:
and then at the end i want sum total price and total taxe of my list created by user in textfield in 2 diffrent textView
like this ->
Total taxe %:
Total prie incl taxe $:
struct Facturation: View {
#Environment(\.managedObjectContext) private var viewContext
#FetchRequest(entity: FacturationCoreData.entity(), sortDescriptors: []) private var factures: FetchedResults<FacturationCoreData>
#State private var article = ""
#State private var prix = ""
#State private var quantite = ""
#State private var tvac = ""
#State private var tva = [0, 6, 12, 21]
#State private var tipIndex = 2
#AppStorage("textChange") private var textChange = ""
func prixQuantite() -> Double {
let fact = FacturationCoreData(context: viewContext)
let prix = fact.prix ?? ""
let quan = fact.quantite ?? ""
let sum = ((Double(prix) ?? 00) * (Double(quan) ?? 00))
return sum
}
func calculeTvaC() ->Double {
let fact = FacturationCoreData(context: viewContext)
let prixEtQuantite = prixQuantite()
let tva = fact.tva ?? ""
let prixTTC = ((prixEtQuantite / 100 * (Double(tva ?? "") ?? 00)) +
prixEtQuantite)
return prixTTC
}
var body: some View {
NavigationView{
VStack {
Form {
Section("Article"){
TextField("Article", text: $article)
.disableAutocorrection(true)
}
HStack{
Section("Q"){
TextField("Quantite", text: $quantite)
.keyboardType(.decimalPad)
}
Section("P") {
TextField("Prix", text: $prix)
.keyboardType(.decimalPad)
}
Section("T") {
TextField("TVA", text: $tvac)
.keyboardType(.decimalPad)
}
}
Button {
let facture = FacturationCoreData(context: viewContext)
facture.article = article
facture.quantite = quantite
facture.prix = prix
facture.tva = tvac
do{
try viewContext.save()
}catch{
print(error)
}
} label: {
Image(systemName: "square.and.arrow.down.fill")
.font(.title)
}
List{
ForEach(factures) { facture in
VStack(alignment: .leading){
Text("Artile: " + (facture.article ?? ""))
Text("Quantité: " + (facture.quantite ?? "") + "x")
Text("Prix: " + (facture.prix ?? "") + "€")
Text("Tva: " + (facture.tva ?? "") + "%")
Text("Total price:\(prixQuantite())$ ")
Text("Total taxe:\(calculeTvaC())$ ")
}.onTapGesture {
textChange = facture.article ?? ""
}
}.onDelete { indexSet in
indexSet.forEach { index in
let deletfacture = factures[index]
viewContext.delete(deletfacture)
do{
try viewContext.save()
}catch{
print(error)
}
}
}
}
}
Text(textChange)
}
.navigationTitle("Facturation")
.toolbar {
ToolbarItem(placement: .navigationBarTrailing) {
NavigationLink {
Client()
} label: {
Image(systemName: "person.badge.plus")
}
}
ToolbarItem(placement: .navigationBarLeading) {
NavigationLink {
ClientList()
} label: {
Image(systemName: "list.bullet")
}
}
ToolbarItem(placement: .navigationBarTrailing) {
EditButton()
}
}
}
}

Answer 1

You can use an extension
extension FacturationCoreData{
var prixQuantite : Double {
let prix = self.prix ?? ""
let quan = self.quantite ?? ""
let sum = ((Double(prix) ?? 00) * (Double(quan) ?? 00))
return sum
}
var calculeTvaC : Double {
let prixEtQuantite = prixQuantite
let tva = self.tva ?? ""
let prixTTC = ((prixEtQuantite / 100 * (Double(tva ?? "") ?? 00)) +
prixEtQuantite)
return prixTTC
}
}
Then you can use
Text("Total price:\(facture.prixQuantite)$ ")
Text("Total taxe:\(facture.calculeTvaC)$ ")