Updating Member of an Array - ios

Question

Newbie here.
My problem simplified:
I have a Person struct consisting of 2 strings - first and last name.
An initial array with a few persons (ex. "Bob" "Smith", "Joe" "Johnson", etc.)
A list view showing each member.
Clicking on a row in the list shows a detail view - call it "person card" view - which shows the first name and last name.
I then have a modal view to edit these variables.
Currently the Save button on the modal only closes the modal. However, because I am using bindings on the modal view to the values on the "person card" view, the "person card" view is updated with the changed data when the modal closes.
The list view though still shows the original value(s) and not the updated data (as I expect). I know that I have to add as method to the save function but I'm not sure what. I know how to insert and append to an array but I can't find an update array method.
FYI - The data model I am using is a "store" instance of a class that is an ObservableObject. I have that variable declared as an EnvironmentObject on each view.
Here is the code as requested:
struct PatientData: Identifiable
{
let id = UUID()
var patientName: String
var age: String
}
let patientDataArray: [PatientData] =
[
PatientData(patientName: "Charles Brown", age: "68"),
PatientData(patientName: "Jim Morrison", age: "36"),
]
final class PatientDataController: ObservableObject
{
#Published var patients = patientDataArray
{
struct PatientList: View
{
#EnvironmentObject var patientDataController: PatientDataController
#State private var showModalSheet = false
var body: some View
{
NavigationView
{
List
{
ForEach(patientDataController.patients)
{ patientData in NavigationLink(destination: PatientInfoCard(patientData: patientData))
{ PatientListCell(patientData: patientData) }
}
.onMove(perform: move)
.onDelete(perform: delete)
.navigationBarTitle(Text("Patient List"))
}
struct PatientInfoCard: View
{
#EnvironmentObject var patientDataController: PatientDataController
#State var patientData: PatientData
#State private var showModalSheet = false
var body: some View
{
VStack(alignment: .leading, spacing: 8)
{ // Change to patientDataArray???
Text(patientData.patientName)
.font(.largeTitle)
BasicInfo(patientData: patientData)
Spacer()
.frame(minWidth: 0, maxWidth: .infinity)
}
.padding()
// Can't push Edit button more than once
.navigationBarItems(trailing: Button(action:
{self.showModalSheet = true})
{Text("Edit")})
.sheet(isPresented: $showModalSheet)
{
EditPatientModal(patientData: self.$patientData, showModalSheet: self.$showModalSheet)
.environmentObject(self.patientDataController)
}
}
}
struct EditPatientModal: View
{
#Environment(\.presentationMode) var presentationMode
#EnvironmentObject var patientDataController: PatientDataController
#Binding var patientData: PatientData
#Binding var showModalSheet: Bool
var body: some View
{
NavigationView
{
VStack(alignment: .leading)
{
Text("Name")
.font(.headline)
TextField("enter name", text: $patientData.patientName)
Text("Age")
.font(.headline)
TextField("enter age", text: $patientData.age)
}
.navigationBarTitle(Text("Edit Patient"), displayMode: .inline)
.navigationBarItems(
leading: Button("Cancel")
{ self.cancel() },
trailing: Button("Save")
{ self.save() } )
}
}
private func save()
{
self.presentationMode.wrappedValue.dismiss()
}
Here is my updated code:
class PatientData: ObservableObject, Identifiable
{
let id = UUID()
#Published var patientName = ""
#Published var age = ""
init(patientName: String, age: String)
{
self.patientName = patientName
self.age = age
}
}
let patientDataArray: [PatientData] =
[
PatientData(patientName: "Charles Brown", age: "68"),
PatientData(patientName: "Jim Morrison", age: "36")
]
final class PatientDataController: ObservableObject
{
#Published var patients = patientDataArray
}
struct PatientList: View
{
#EnvironmentObject var patientDataController: PatientDataController
#EnvironmentObject var patientData: PatientData
#State private var showModalSheet = false
var body: some View
{
NavigationView
{
List
{
ForEach(self.patientDataController.patients.indices)
{ idx in
NavigationLink(destination: PatientInfoCard(patientData: self.$patientDataController.patients[idx]))
/*Cannot convert value of type 'Binding<PatientData>' to expected argument type 'PatientData'*/ <-- My one error message; in NavigationLink
{ PatientListCell(patientData: self.$patientDataController.patients[idx]) }
}
.onMove(perform: move)
.onDelete(perform: delete)
.navigationBarTitle(Text("Patient List"))
}
.navigationBarItems(leading: EditButton())
struct PatientInfoCard: View
{
#EnvironmentObject var patientDataController: PatientDataController
#Binding var patientData: PatientData
#State private var showModalSheet = false
var body: some View
{
VStack(alignment: .leading, spacing: 8)
{
Text(patientData.patientName)
.font(.largeTitle)
BasicInfo(patientData: patientData)
Spacer()
.frame(minWidth: 0, maxWidth: .infinity)
}
.padding()
.navigationBarItems(trailing: Button(action:
{self.showModalSheet = true})
{Text("Edit")})
.sheet(isPresented: $showModalSheet)
{
EditPatientModal(patientData: self.$patientData, showModalSheet: self.$showModalSheet)
.environmentObject(self.patientDataController)
}
}
}
struct BasicInfo: View
{
#EnvironmentObject var patientDataController: PatientDataController
#State var patientData: PatientData
var patientDataIndex: Int
{
patientDataController.patients.firstIndex(where: { $0.id == patientData.id })!
}
var body: some View
{
VStack(alignment: .leading, spacing: 8)
{
Text("Age:")
.font(.headline)
Text(patientData.age)
.font(.subheadline)
.foregroundColor(.secondary)
}
}
}
struct EditPatientModal: View
{
#Environment(\.presentationMode) var presentationMode
#EnvironmentObject var patientDataController: PatientDataController
#Binding var patientData: PatientData
#Binding var showModalSheet: Bool
var body: some View
{
NavigationView
{
VStack(alignment: .leading)
{
Text("Name")
.font(.headline)
TextField("enter name", text: $patientData.patientName)
Text("Age")
.font(.headline)
TextField("enter age", text: $patientData.age)
}
.navigationBarTitle(Text("Edit Patient"), displayMode: .inline)
.navigationBarItems(
leading: Button("Cancel")
{ self.cancel() },
trailing: Button("Save")
{ self.save() } )
}
}
private func save()
{
self.presentationMode.wrappedValue.dismiss()
}

Answer 1

You are missing 2 things in your code.
Your struct needs to be ObservableObject otherwise any changes happen to it will not get effected and in order for it to be ObservableObject it has to be a class so first change:
class PatientData: ObservableObject, Identifiable
{
let id = UUID()
#Published var patientName: String
#Published var age: String
init(patientName: String, age: String) {
self.patientName = patientName
self.age = age
}
}
I understand you have an environmentObject which is publishing, but it's only publishing changes to the array, meaning adding or removing items but not to individual patientData objects.
2nd thing to change is in your forEach loop you need pass Patient as a Bind and in order to do that you have to loop through indices and then access the data through Bind
NavigationView
{
if(self.patientDataController.patients.count > 0) {
List {
ForEach(self.patientDataController.patients.enumerated().map({$0}), id:\.element.id) { idx, patient in
NavigationLink(destination: PatientInfoCard(patientData: self.$patientDataController.patients[idx])) {
Text(patient.patientName)
}
}
}
.navigationBarItems(leading: EditButton())
} else {
Text("List is empty")
}
}
Let us know if this doesn't work