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.
WeagleWeagle
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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:
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
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!
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!
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'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'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!
Anyone have any idea as to how to embed an SwiftUI View in a UITabBarController. From what I understand they were made to contain views made from UIKit and my views are made from SwiftUI so I’m not exactly sure how to use a UITabBarController in the storyboard with the views that I have. Any help would be greatly appreciated!
Anyone have any idea as to how to embed an SwiftUI View in a UITabBarController. From what I understand they were made to contain views made from UIKit and my views are made from SwiftUI so I’m not exactly sure how to use a UITabBarController in the storyboard with the views that I have.
Any help would be greatly appreciated!
I need a picker exactly like the one in the picture (Apple’s timer app), but without the seconds. I’ve found that this is a UIDatePicker in the .countDownTimer mode. But my program runs on swiftUI instead of UIKit. Is there any way I could still use this or is there a swiftUI version? Thanks!
I had the idea of adding a list feature in my app where users can create a list and add multiple recipes to the app so first and only thing I did was add an entity to my data model called "List" that contains a string: title and an array of Recipes: recipes (I remembered to put "NSSecureUnarchiveFromData" in Transformer and put [Recipe] for custom class). Afterwards I made the relationship in both entities and made them inverse.
I made no other changes to my code. But I ran it just to make sure nothing went wrong and lo and behold: 7 never before seen errors, but only in one file. Before adding this entity this same code compiled just fine. This is the file and these are the errors I'm getting. Any help would be greatly appreciated.
import SwiftUI
struct RecipeView: View {
@Environment (\.managedObjectContext) var managedObjContext
@Environment(\.dismiss) var dismiss
var recipe: FetchedResults<Recipe>.Element
@State var isFavorite: Bool
@State var servings = -1
var body: some View {
VStack(alignment: .leading){ //Error: Trailing closure passed to parameter of type 'CGFloat?' that does not accept a closure
if (recipe.notes! != ""){
Section{
Text(recipe.notes!)
.font(.headline)
}
.padding(.horizontal)
}
HStack{
Spacer()
Text("Total Time: "+calcTime(time:Int(recipe.totalTime!) ?? 0))
Spacer()
Text("Servings: "+recipe.servings!)
Spacer()
}
.padding(.vertical)
Grid{
GridRow{
Button {
isFavorite.toggle()
recipe.isFavorite.toggle()
PersistenceController().save(context: managedObjContext)
} label: {
HStack{
Image(systemName: isFavorite ? "star.fill" : "star")
.foregroundStyle(.yellow)
Text(isFavorite ? "Unfavorite" : "Favorite")
.foregroundColor(Color(UIColor.lightGray))
}
.frame(width: 300,height: 50)
.background(Color(UIColor(hexString: "#202020")))
.border(Color(UIColor(hexString: "#202020")))
.cornerRadius(5)
}
Button {
print("implement list functionality")
} label: {
Image(systemName: "plus")
.frame(width: 50,height: 50)
.background(Color(UIColor(hexString: "#202020")))
.border(Color(UIColor(hexString: "#202020")))
.cornerRadius(5)
}
}
}
.padding(.horizontal)
List{
NavigationLink(destination: ingredientsView(ingredients: recipe.ingredients!)){
HStack{
Text("List of Ingredients")
Spacer()
Text(String(recipe.ingredients!.count))
.foregroundColor(.gray)
}
}
.frame(height: 50)
NavigationLink(destination: instructionsView(instructions: recipe.instructions!)){
HStack{
Text("List of Instructions")
Spacer()
Text(String(recipe.instructions!.count))
.foregroundColor(.gray)
}
}
.frame(height: 50)
}
.listStyle(.grouped)
.scrollDisabled(true)
Spacer()
}
.navigationBarTitle(recipe.title!)
.navigationBarItems(trailing: shareButton)
.onAppear{
PersistenceController().updateDate(recipe: recipe, context: managedObjContext)
}
Spacer()
}
var shareButton: some View{
Button(action: {
print("Implement airdrop feature")
}){
Image(systemName: "square.and.arrow.up")
.foregroundStyle(.blue)
}
}
}
struct ingredientsView: View{
@State var ingredients: [String]
var body: some View{
List{ // Error: Trailing closure passed to parameter of type 'NSManagedObjectContext' that does not accept a closure
Section(""){
ForEach(ingredients,id: \.self){ String in
NavigationLink(destination:
NavigationView{
Text(String)
.frame(alignment:.center)
.font(.title)
}){
Text(String).lineLimit(1)
}
}
}
}
.frame(alignment: .center) //Error: Cannot infer contextual base in reference to member 'center'
//Error: Value of type 'List' has no member 'frame'
.cornerRadius(10)
.navigationTitle("Ingredients List")
}
}
struct instructionsView: View{
@State var instructions: [String]
var body: some View{
List{ // Error: Trailing closure passed to parameter of type 'NSManagedObjectContext' that does not accept a closure
Section(""){
ForEach(instructions,id: \.self){ String in
NavigationLink(destination:
NavigationView{
Text(String)
.frame(alignment:.center)
.font(.title)
}){
Text(String).lineLimit(1)
}
}
}
}
.frame(alignment: .center) //Error: Cannot infer contextual base in reference to member 'center'
//Error: Value of type 'List' has no member 'frame'
.cornerRadius(10)
.navigationTitle("Instructions List")
}
}
I need a wheel picker for hours and minutes. I've found stuff online but it does have the "Hours" and "Minutes" right after and it isn't as compact. Is there a newer way to accomplish this to look exactly like it does in the timer app?
How do I make it so that these two textfields aren't connected? They should have two separate backgrounds.
I need to enlarge my text field. So I tried using a frame, but that only put dead space around it. The problem with that is I want to be able to click anywhere inside the boarder and it pull up the keyboard. So I tried padding and that did the same thing. Also I need the text to start a new line after it fills the first one and to go for as long as they type. Thanks!