I'm sorry I know this is basic swift, but how do I get I make the selection an optional return? I know it's with ?? "" with a string, but I don't know how to do it with a date type.
Also how do I get a navigationBarTitle to work on this view? The "My Calendar" doesn't show up when I run the code.
import SwiftUI
struct ReciPrep: View {
@State private var date: Date? = ni
@Environment(\.calendar) var calendar
@State private var showingAddView = false
var body: some View {
VStack{
DatePicker("Calendar", selection: $date, in: Date.now...,displayedComponents: [.date]) //Error: Cannot convert value of type 'Binding<Date?>' to expected argument type 'Binding<Date>'
.datePickerStyle(.graphical)
Spacer()
}
.navigationBarTitle("My Calendar")
}
}
Any help would be greatly appreciated. Have a good day!
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I've made a simplified version of what I'm trying to do in the included code, but basically I'm trying to make a view that edits a data model. This edit view shows up when a button in a context menu is clicked. The problem is no matter which one I open up the context menu on it always opens up whichever one I clicked first. The reference to the object in the .sheet never changes. How can I fix this??
Example Code:
import SwiftUI
class Object: Identifiable{
var id: UUID?
var title: String
var string: String
init(title: String, string: String) {
self.id = UUID()
self.title = title
self.string = string
}
}
struct ContentView: View {
@State private var showingEditView = false
@State private var objectList = [Object(title: "First", string: "Editor"), Object(title: "Second", string: "Addition"), Object(title: "Third", string: "Twelve")]
var body: some View {
NavigationView{
List{
Section("Objects"){
ForEach(objectList) { object in
NavigationLink(destination: ObjectView(obj: object)){
Text(object.title)
}
.sheet(isPresented: $showingEditView){
EditView(obj: object)
}
}
}
.contextMenu{
Button(action: {
self.showingEditView.toggle()
}){
Text("Edit Item")
}
}
}
.listStyle(InsetGroupedListStyle())
.cornerRadius(10)
.navigationBarTitle("My List")
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
struct ObjectView: View {
@State var obj: Object
var body: some View {
NavigationView{
VStack{
Text(obj.string)
}
.navigationBarTitle(obj.title)
}
}
}
struct EditView: View {
@Environment(\.dismiss) var dismiss
@State var obj: Object
@State var word = ""
var body: some View {
NavigationView{
Form{
TextField("Change Word", text: $word)
.onAppear(perform: {
word = obj.string
})
}
.navigationBarItems(trailing:
Button(action: {
dismiss()
}){
Text("Done")
.bold()
})
}
}
}
Any help would be greatly appreciated. All the best!
I need to dismiss a sheet that doesn't call a view inside of it instead it makes it's own view. The reason this is necessary is because the view changes an attribute of an object in the previous view which won't update unless the attribute is changed in the same struct. Is there any way I could dismiss the view without swiping down in this way? Or a way I can pass a reference to the attribute so that when I change it in a separate struct it will update live in a previous one
I'm sorry for my super confusing explanation. I've simplified my actual implemented code to the following:
struct ContentView: View {
@Environment(\.dismiss) var dismiss
@State var word = ""
@State private var isSheetShowing = false
var body: some View {
NavigationView{
Form{
TextField("Change Word", text: $word)
Button(action: {
isSheetShowing.toggle()
}){
Text("Done")
.bold()
}
.sheet(isPresented: $isSheetShowing){
NavigationView{
List{
Text("Hello User")
}
.navigationBarItems(leading:
Button(action: {
dismiss()
}){
Text("Cancel")
.bold()
})
}
}
}
}
}
}
Pressing cancel in the sheet does not dismiss the view as I want it to.
I need to edit an attribute of a core data entity fetched in a previous view. So I put var entityName: FetchedResults.Elementin the second view to get access to the entity. But when I do this it doesn't actually get the entity it gets a copy of the entity so when changes are made to it it doesn't actually change. Basically is there a way to pass a reference to an attribute of an object to a struct so that when you set that reference to a value the entity changes?
Any help would be greatly appreciated. All the best!
Basically I need a view with a calendar that will show data attributes from the item. I've tried two different approaches both have their listed problems. There must be a better way to do something like this. Surely it's not ideal to create a new item every time a date is opened or constantly check if something is there, but I don't know any other way.
Actual View:
import SwiftUI
import CoreData
struct ContentView: View {
@Environment(\.managedObjectContext) var managedObjContext
@Environment(\.calendar) var calenda
@Environment(\.dismiss) var dismiss
@FetchRequest(sortDescriptors: [], predicate: NSPredicate(format: "timestamp == %@", Date.now as CVarArg)) var items: FetchedResults<Item>
@State private var date = Date.now
var body: some View {
NavigationView{
VStack{
DatePicker("Calendar", selection: $date, in: Date.now...,displayedComponents: [.date])
.datePickerStyle(.graphical)
.onAppear(perform: {
if (items.isEmpty){
PersistenceController().addItem(date: date, context: managedObjContext)
}
})
.onChange(of: date){ value in
items.nsPredicate=NSPredicate(format: "timestamp == %@", date as CVarArg)
if (items.isEmpty){
PersistenceController().addItem(date: date, context: managedObjContext)
}
}
if (!items.isEmpty){
//This is the only difference in the two approaches. I just put either one of the next two blocks of code in here
}
}
.navigationBarTitle("My Planner")
}
}
func getTitle(date: Date)->String{
let formatter = DateFormatter()
formatter.dateStyle = .medium
return formatter.string(from: date)
}
}
First (looks correct, but doesn't show the changes live):
PlannedMealsView(item: items[0])
Spacer()
//And then this is added at the bottom
struct PlannedMealsView: View {
@Environment(\.managedObjectContext) var managedObjContext
@State var item: Item
var body: some View {
VStack{
Text(item.timestamp ?? Date.now, style: .date)
.font(.title2)
.bold()
Section("Word"){
if(item.word != nil){
HStack{
Spacer()
Text(item.word!)
Spacer()
Button(action: {
PersistenceController().removeFromItem(item: item, context: managedObjContext)
}){
Image(systemName: "minus.circle").bold()
}
Spacer()
}
} else {
Button(action: {
PersistenceController().addToItem(item: item, context: managedObjContext)
}){
Image(systemName: "plus.circle").bold()
.padding(.vertical, 10)
.padding(.horizontal, 20)
}
}
}
Spacer()
}
.frame(height:200)
}
}
Second (allows direct access to the objects data, but bugs after 5 or 6 date changes):
VStack{
Text(items[0].timestamp ?? Date.now, style: .date)
.font(.title2)
.bold()
Section("Word"){
if(items[0].word != nil){
HStack{
Spacer()
Text(items[0].word!)
Spacer()
Button(action: {
PersistenceController().removeFromItem(item: items[0], context: managedObjContext)
}){
Image(systemName: "minus.circle").bold()
}
Spacer()
}
} else {
Button(action: {
PersistenceController().addToItem(item: items[0], context: managedObjContext)
}){
Image(systemName: "plus.circle").bold()
.padding(.vertical, 10)
.padding(.horizontal, 20)
}
}
}
Spacer()
}
.frame(height:200)
Unchanged Files:
Persistence-
import CoreData
struct PersistenceController {
static let shared = PersistenceController()
let container: NSPersistentContainer
init(inMemory: Bool = false) {
container = NSPersistentContainer(name: "Test")
if inMemory {
container.persistentStoreDescriptions.first!.url = URL(fileURLWithPath: "/dev/null")
}
container.loadPersistentStores(completionHandler: { (storeDescription, error) in
if let error = error as NSError? {
fatalError("Unresolved error \(error), \(error.userInfo)")
}
})
container.viewContext.automaticallyMergesChangesFromParent = true
}
func addItem(date: Date, context: NSManagedObjectContext){
let item = Item(context: context)
item.timestamp = date
item.word = nil
save(context: context)
}
func addToItem(item: Item, context: NSManagedObjectContext){
item.word = "Test"
save(context: context)
}
func removeFromItem(item: Item, context: NSManagedObjectContext){
item.word = nil
save(context: context)
}
func save(context: NSManagedObjectContext){
do {
try context.save()
} catch {
let nsError = error as NSError
fatalError("Unresolved error \(nsError), \(nsError.userInfo)")
}
}
}
Data Model-
If you have any questions I'll be happy to answer. Any help is greatly appreciated. All the best!
Does anyone know the best way to store core data using a calendar? The only way I could think is adding a date attribute and every time the date is changed on the calendar changing the NSPredicate to that date and if there isn’t one creating a new instance with that date as it’s date value. I’m certain this is not the best method, but I couldn’t think of any other, but I know I’m very limited in my SwiftUI knowledge. So any guidance would be greatly appreciated.
For more insight into what I’m looking for see my previous post asking for advice on what to change about my own method: https://developer.apple.com/forums/thread/708915
I have an object called Item with two attributes, name (String) and value (Double). Given an array of Items I need combine the values of all items with the same name and keep the items with no duplicates. For example, say there were 4 items in the array and two of them named "Test" and the others "Object" and "Item". "Object" and "Item" would remain in the list, but the values of the two "Test"s would be combined into one item with the same name "Test".
I've included the following code for a visual representation.
Delete the comments as you read them to clean up. They're just there to clear up any confusion. Leave a comment if you have any questions. Thanks for the help!
Content View:
import SwiftUI
import CoreData
struct ContentView: View {
@Environment(\.managedObjectContext) var managedObjContext
@ObservedObject var persistence = PersistenceController.shared
@State private var items = PersistenceController.shared.getItems()
@State var isAddViewShowing = false
var body: some View {
NavigationView{
List{
Section{
ForEach(items) { item in //Displays the list of items
HStack{
Text(String(item.name!))
Spacer()
Text(String(Int(item.value)))
}
}
.onDelete(perform: { indexSet in
deleteItem(indexSet: indexSet)
})
}
}
.navigationBarTitle("Items")
.navigationBarItems(leading: combineItemsButton, trailing: addButton)
.sheet(isPresented: $isAddViewShowing){ //displays the view to add an item
AddView()
.onDisappear(perform: {
items = persistence.getItems() //"refreshes" the list of items
})
}
}
}
var combineItemsButton: some View{
Button(action:{
//combine duplicates here
persistence.contextSave()
items = persistence.getItems()
}){
Text("Combine Duplicates")
.bold()
}
}
var addButton: some View{
Button(action:{
isAddViewShowing.toggle()
}){
Text("Add Item")
.bold()
}
}
func deleteItem(indexSet: IndexSet){
withAnimation{
indexSet.map {
items[$0]
}
.forEach(managedObjContext.delete)
persistence.contextSave()
items = persistence.getItems()
}
}
}
Add View:
struct AddView: View{
@Environment(\.dismiss) var dismiss
@ObservedObject var persistence = PersistenceController.shared
@State var name: String = ""
@State var value = ""
@State private var alertMessage = ""
@State private var showAlert = false
var body: some View{
NavigationView{
Form{
TextField("Item Name", text: $name)
TextField("Item Value", text: $value)
.keyboardType(.decimalPad)
}
.navigationBarTitle("Add Item")
.navigationBarItems(leading: dismissButton, trailing: submitButton)
}
}
var submitButton: some View{
Button(action: {
if (name == ""){ //ensures the item has a name
alertMessage="Your recipe needs a name"
showAlert.toggle()
} else {
persistence.addItem(name: name, value: Double(value) ?? 2)
dismiss()
}
}){
Text("Submit")
.bold()
}
.alert(alertMessage, isPresented: $showAlert){
Button("OK",role: .cancel){}
}
}
var dismissButton: some View{
Button(action: {
dismiss()
}){
Text("Cancel")
.bold()
}
}
}
Persistence File:
import CoreData
class PersistenceController : ObservableObject{
static let shared = PersistenceController()
let container: NSPersistentContainer
init(inMemory: Bool = false) {
container = NSPersistentContainer(name: "Test")
if inMemory {
container.persistentStoreDescriptions.first!.url = URL(fileURLWithPath: "/dev/null")
}
container.loadPersistentStores(completionHandler: { (storeDescription, error) in
if let error = error as NSError? {
fatalError("Unresolved error \(error), \(error.userInfo)")
}
})
container.viewContext.automaticallyMergesChangesFromParent = true
}
func getItems() -> [Item] { //fetches items
let context = container.viewContext
var request = NSFetchRequest<Item>()
request = Item.fetchRequest()
request.entity = NSEntityDescription.entity(forEntityName: "Item", in: context)
do {
let items = try context.fetch(request)
if items.count == 0 { return []}
return items.sorted(by: {$0.name! > $1.name!})
} catch {
print("**** ERROR: items fetch failed \(error)")
return []
}
}
func addItem(name: String, value: Double){
let context = container.viewContext
let item = Item(context: context)
item.id = UUID()
item.name = name
item.value = value
contextSave()
}
func contextSave() {
let context = container.viewContext
if context.hasChanges {
do {
try context.save()
self.objectWillChange.send()
} catch {
print("**** ERROR: Unable to save context \(error)")
}
}
}
}
Data Model:
So I have a TabView in my app and I want to go back yo the main view when that tabItem is pressed. For example, when you open the App Store and go to the games tab, click on a game. It takes you to a navigation link to a new view. You can either go back to the first page by pressing the arrow, or by tapping the “games” tabItem again. I want to be able to press my tabItem in a subview of the same tab to go back to the original view that the tab is assigned to.
So this project is pretty straightforward. I have an item. The use can create, get a closer look at, delete, or edit an item. For some reason, no matter how many different ways I try to do it, the edit part does not work. I've tried moving the sheet outside of the context menu (it only opens the bottom item), I've tried moving it under the list using the first index of the item (it crashes), and finally I've tried it the shown way and it just doesn't do anything. If anyone can come up with a better way to open the edit view for the correct item (preferably using a context menu, but something similar is acceptable) I would really appreciate it.
I've provided the project for a better understanding of what I'm trying to do. If you have any questions just leave a comment.
Any help would be greatly appreciated.
Content View:
struct ContentView: View {
@Environment(\.managedObjectContext) var managedObjContext
@ObservedObject var persistence = PersistenceController.shared
@State private var items = PersistenceController.shared.getItems()
@State private var showingEditView = false
@State private var showingAddView = false
var body: some View {
NavigationView{
List{
Section(""){
ForEach(items) { item in
NavigationLink(destination: ItemView(item: item)){
Text(item.name!)
}
.contextMenu{
Button(action: {
self.showingEditView.toggle()
}){
Text("Edit Item")
}
.sheet(isPresented: $showingEditView){
EditItemView(item: item)
.onDisappear(perform: {
items = persistence.getItems()
})
}
}
}
.onDelete(perform: { indexSet in
deleteItem(indexSet: indexSet)
})
}
}
.listStyle(InsetGroupedListStyle())
.cornerRadius(10)
.navigationBarTitle("My Items")
.navigationBarItems(trailing: addButton)
.onAppear(perform: {
items = persistence.getItems()
})
.sheet(isPresented: $showingAddView){
AddItemView()
.onDisappear(perform: {
items = persistence.getItems()
})
}
}
}
var addButton: some View {
Button(action: {
showingAddView.toggle()
}){
Text("Add an Item").bold()
}
}
func deleteItem(indexSet: IndexSet){
withAnimation{
indexSet.map {
items[$0]
}
.forEach(managedObjContext.delete)
persistence.contextSave()
items = persistence.getItems()
}
}
}
Item View:
struct ItemView: View{
@State var item: Item
var body: some View{
Text(item.name ?? "No Name")
}
}
Add View:
struct AddItemView: View{
@Environment(\.dismiss) var dismiss
@ObservedObject var persistence = PersistenceController.shared
@State private var name = ""
var body: some View {
Form{
TextField("Item Name", text: $name)
Button(action:{
persistence.addItem(name: name)
dismiss()
}){
Text("Add Item")
}
}
}
}
Edit View:
struct EditItemView: View{
@Environment(\.dismiss) var dismiss
@ObservedObject var persistence = PersistenceController.shared
@State var item: Item
@State private var name = ""
var body: some View {
Form{
TextField("Item Name", text: $name)
Button(action:{
persistence.addItem(name: name)
dismiss()
}){
Text("Add Item")
}
}
.onAppear{
name=item.name ?? "No Name"
}
}
}
Persistence File:
class PersistenceController : ObservableObject{
static let shared = PersistenceController()
let container: NSPersistentContainer
init(inMemory: Bool = false) {
container = NSPersistentContainer(name: "Test")
if inMemory {
container.persistentStoreDescriptions.first!.url = URL(fileURLWithPath: "/dev/null")
}
container.loadPersistentStores(completionHandler: { (storeDescription, error) in
if let error = error as NSError? {
fatalError("Unresolved error \(error), \(error.userInfo)")
}
})
container.viewContext.automaticallyMergesChangesFromParent = true
}
static var preview: PersistenceController = {
let result = PersistenceController(inMemory: true)
let viewContext = result.container.viewContext
for _ in 0..<10 {
let newItem = Item(context: viewContext)
newItem.id = UUID()
newItem.name = "Test"
}
do {
try viewContext.save()
} catch {
let nsError = error as NSError
fatalError("Unresolved error \(nsError), \(nsError.userInfo)")
}
return result
}()
func getItems() -> [Item] {
let context = container.viewContext
var request = NSFetchRequest<Item>()
request = Item.fetchRequest()
request.entity = NSEntityDescription.entity(forEntityName: "Item", in: context)
do {
let items = try context.fetch(request)
if items.count == 0 { return []}
return items.sorted(by: {$0.name! > $1.name!})
} catch {
print("**** ERROR: items fetch failed \(error)")
return []
}
}
func addItem(name: String){
let context = container.viewContext
let item = Item(context: context)
item.id = UUID()
item.name = name
contextSave()
}
func contextSave() {
let context = container.viewContext
if context.hasChanges {
do {
try context.save()
self.objectWillChange.send()
} catch {
print("**** ERROR: Unable to save context \(error)")
}
}
}
}
Data Model:
I need help optimizing and fixing my date list builder. Basically the user should be able to build a list of dates in a sheet and it be shown on the original view and go back to that page to add more. Dates should not be repeated hence why I use a set.
Issue: But when the user adds the first date it doesn't show until a second date is added. After some troubleshooting with print I've found that the problem isn't adding the first item to the list, but the ForEach not working until there is a second item.
I've included code for a visual representation of my goal. If you have any questions please leave a comment. Any help would be greatly appreciated. Thanks!
import SwiftUI
struct ContentView: View {
@State private var dates = Set<Date>()
@State private var isDatesShowing = false
var body: some View {
NavigationView{
Form{
Section(""){
addDatesButton
Section{
ForEach(dates.sorted(by: <),id: \.self){ date in
Text(date, style: .date)
.bold()
.foregroundColor(.white)
}
}
}
}
.navigationBarTitle("List of Dates")
.sheet(isPresented: $isDatesShowing){
AddToDateView(dates: $dates)
}
}
.preferredColorScheme(.dark)
}
var addDatesButton: some View{
Button(action: {
isDatesShowing.toggle()
}){
Text("Select Dates")
.bold()
}
}
}
struct AddToDateView: View {
@Environment(\.dismiss) var dismiss
@Binding var dates: Set<Date>
@State var date = Date()
var body: some View {
NavigationView{
Form{
DatePicker(selection: $date, in: Date.now..., displayedComponents: .date) {
Text("Select a date")
}
.datePickerStyle(WheelDatePickerStyle())
Button(action:{
dates.insert(date)
}){
Text("Add Date")
}
Section("Dates"){
ForEach(dates.sorted(by: <),id: \.self){ date in
Button(action: {
dates.remove(date)
}){
Text(date, style: .date)
.bold()
.foregroundColor(.white)
}
}
}
}
.cornerRadius(10)
.navigationBarItems(trailing: submitButton)
}
}
var submitButton: some View{
Button(action: {
dismiss()
}){
Text("Submit")
.bold()
}
}
}
So I know this is probably a stretch, but is there any way to airdrop an object from core data? From what I understand airdrop is only used with links, but is there a way to convert the data of a core data object into a file, convert the file into a link, send it via airdrop, and convert it back into a file, and then add that object from a file to another user's core data storage?
Any help would be greatly appreciated. Thanks!!
So I have a TabView in my app and I want to go back yo the main view when that tabItem is pressed. For example, when you open the App Store and go to the games tab, click on a game. It takes you to a navigation link to a new view. You can either go back to the first page by pressing the arrow, or by tapping the “games” tabItem again. I want to be able to press my tabItem in a subview of the same tab to go back to the original view that the tab is assigned to.
So I know this is probably a stretch, but is there any way to airdrop an object from core data? From what I understand airdrop is only used with links, but is there a way to convert the data of a core data object into a file, convert the file into a link, send it via airdrop, and convert it back into a file, and then add that object from a file to another user's core data storage?
Any help would be greatly appreciated. Thanks!!
I'm developing an app that has accounts with usernames and passwords to log in. So far I have found firebase, which doesn't look bad, but I'd like to know every available option and what they have to offer before committing to one.
I was curious if Apple had some sort of kit for developers for a login system. And if not maybe other options for this.
Thanks for any help!
I'm developing an app that has accounts with usernames and passwords to log in. So far I have found firebase, which doesn't look bad, but I'd like to know every available option and what they have to offer before committing to one.
I was curious if Apple had some sort of kit for developers for a login system. Like CloudKit for example, can CloudKit be used to store log in info and be reached when the user is logging in? And if not maybe other options for this.
Thanks for any help!