I'm having an issue in Xcode 14 beta where as you can see in the images below the keyboard is dismissed after entering some text whereas in iOS 15 the keyboard stays in place which is the behaviour I want.
What I'm doing is in .onSubmit I'm creating a new item and setting it's focus programatically.
iOS 15 (Xcode 13.4.1)
iOS 16 (Xcode 14 beta 3)
MRE:
enum Focusable: Hashable {
case none
case row(id: UUID)
}
extension View {
func sync<T: Equatable>(_ field1: Binding<T>, _ field2: FocusState<T>.Binding ) -> some View {
self
.onChange(of: field1.wrappedValue) {
field2.wrappedValue = $0
}
.onChange(of: field2.wrappedValue) {
field1.wrappedValue = $0
}
}
}
class Store: ObservableObject {
struct Item: Identifiable {
var id = UUID()
var name: String
}
#Published var items = [Item]()
#Published var focusedItem: Focusable?
func createNewItem() {
let newItem = Item(name: "")
items.append(newItem)
focusedItem = .row(id: newItem.id)
}
}
struct ContentView: View {
#FocusState private var focusedItem: Focusable?
#StateObject var store = Store()
var body: some View {
NavigationView {
List {
ForEach($store.items) { $item in
TextField("", text: $item.name)
.focused($focusedItem, equals: .row(id: item.id))
.onSubmit(store.createNewItem)
}
}
.toolbar {
ToolbarItem(placement: .confirmationAction) {
Button("New item") {
store.createNewItem()
}
}
}
.sync($store.focusedItem, $focusedItem)
}
}
}
Related
I have an array of custom buttons capsuleButtons in ViewModel.swift file which are displayed using ForEach in ContentView. Each button is connected to an external property named isActive to display its current state, buttons created using the ForEach are not updating where as if created without ForEach (with title ContentView btn), is updating as expected. What am I missing here?
ContentView
struct ContentView: View {
#StateObject var vm = ViewModel()
var body: some View {
VStack {
ForEach(vm.capsuleButtons, id: \.self) { button in
HStack {
button
}
}
CapsuleButton(title: "ContentView btn", action: { vm.isActive.toggle() } , active: vm.isActive)
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
struct CapsuleButton: View, Hashable {
static func == (lhs: CapsuleButton, rhs: CapsuleButton) -> Bool {
lhs.title == rhs.title && lhs.id == rhs.id
}
func hash(into hasher: inout Hasher) {
hasher.combine(title)
hasher.combine(id)
}
var id = UUID()
var title: String
let action: () -> Void
var active = false
var body: some View {
Button(title, action: action)
.background( active ? Color.pink : Color.blue)
.foregroundColor(active ? Color.white : Color.black)
}
}
ViewModel.swift
import Foundation
class ViewModel: ObservableObject {
#Published var isActive = false
var capsuleButtons = [CapsuleButton]()
init() {
self.isActive = false
self.capsuleButtons = [CapsuleButton(title: "Button 1", action: {self.isActive.toggle()}, active: isActive),
CapsuleButton(title: "Button 2", action: {self.isActive.toggle()}, active: isActive)]
}
}
You're doing a few things that are or are close to breaking the SwiftUI diffing system.
First, you're telling the system an untruth by trying to make your View conform to Hashable and Equatable and then saying that the title and id are the only properties that matter, where you definitely also want active to be part of it.
Secondly, in general, you shouldn't be storing references to Views -- especially with IDs that get created on init -- that's a SwiftUI anti pattern. Instead, render a View hierarchy based on your model.
Finally, in your actions, you are always setting self.isActive -- I assume that you actually wanted to set the Button's active state, but you were always setting it on the ViewModel's state.
Something like this (not the only solution) would work instead:
struct ContentView: View {
#StateObject var vm = ViewModel()
var body: some View {
VStack {
ForEach(vm.capsuleButtons) { button in
HStack {
CapsuleButton(model: button) {
vm.action(forID: button.id)
}
}
}
}
}
}
struct CapsuleButtonModel: Identifiable, Hashable {
var id = UUID()
var title: String
var active: Bool
}
struct CapsuleButton: View {
var model: CapsuleButtonModel
let action: () -> Void
var body: some View {
Button(model.title, action: action)
.background(model.active ? Color.pink : Color.blue)
.foregroundColor(model.active ? Color.white : Color.black)
}
}
class ViewModel: ObservableObject {
#Published var isActive = false
#Published var capsuleButtons = [CapsuleButtonModel]()
init() {
self.isActive = false
self.capsuleButtons = [CapsuleButtonModel(title: "Button 1", active: isActive),
CapsuleButtonModel(title: "Button 2", active: isActive)]
}
func action(forID: UUID) {
self.capsuleButtons = self.capsuleButtons.map { btn in
if btn.id == forID {
var copy = btn
copy.active.toggle()
return copy
} else {
return btn
}
}
}
}
You could also get rid of the action(for) function and replace it with a Binding (in particular, read about SwiftUI element binding syntax: https://www.swiftbysundell.com/articles/bindable-swiftui-list-elements/). Then it turns into something even more simple:
struct ContentView: View {
#StateObject var vm = ViewModel()
var body: some View {
VStack {
ForEach($vm.capsuleButtons) { $button in
HStack {
CapsuleButton(model: $button)
}
}
}
}
}
struct CapsuleButtonModel: Identifiable, Hashable {
var id = UUID()
var title: String
var active: Bool
}
struct CapsuleButton: View {
#Binding var model: CapsuleButtonModel
var body: some View {
Button(model.title, action: {
model.active.toggle()
})
.background(model.active ? Color.pink : Color.blue)
.foregroundColor(model.active ? Color.white : Color.black)
}
}
class ViewModel: ObservableObject {
#Published var isActive = false
#Published var capsuleButtons = [CapsuleButtonModel]()
init() {
self.isActive = false
self.capsuleButtons = [CapsuleButtonModel(title: "Button 1", active: isActive),
CapsuleButtonModel(title: "Button 2", active: isActive)]
}
}
I am utilizing a search bar from a Kavsoft Tutorial here: "https://www.youtube.com/watch?v=nuag1PILxCA&t=14s", I'm wondering on how to add navigation links to each of the items, I decided on embedding the itemView inside a navigation link with an array of views to loop through but it seems that it doesn't accept the index as a parameter giving "Cannot convert value of type 'item' to expected argument type 'Int'", instead I incremented the subscript on appear in the navigation link, although that updates the variable, but it doesn't seem to work for the different views themselves only navigating to the first view.
I've linked all the code needed to reproduce the problem but due to my incredibly limited experience in reproducing the problem in as less code as possible, I am not able to do so. Below the main issue of concern is the block starting from the VStack. Starting the program can be done by just adding Search_Bar() to content view body.
struct Home: View {
let views : [AnyView] = [ AnyView(untitled_Skull()), AnyView(dogs()), AnyView(cats()) ]
#Binding var filteredItems : [item]
var body: some View {
ScrollView(.vertical, showsIndicators: false) {
var i = 0
VStack(spacing: 15){
ForEach(filteredItems){index in
NavigationLink(destination: views[i]
) {
itemView(item: index)
}.onAppear() {
i = i + 1
}
}
}
.padding()
}
}
}
func add(value: Int) -> Int {
let value = value + 1
return value
}
struct itemView: View {
var item: item
#State var show = false
var body: some View {
HStack(spacing: 15){
VStack {
let colorArray: [Color] = [.yellowLichtenstien, .redHaring, .orangeBasquiat, .pinkWarhol]
HStack {
Text(item.name)
.foregroundColor(.white)
.bold()
.padding(.leading)
Spacer()
}
HStack {
Text(item.subText)
.bold()
.foregroundColor (.white)
.font(.subheadline)
.padding(.leading)
Circle()
.frame(width: 5, height: 5)
.foregroundColor(colorArray[item.color])
Text(item.subText2)
.bold()
.foregroundColor (.white)
.font(.subheadline)
Spacer()
}
Spacer()
}
}
.padding(.horizontal)
}
}
struct item: Identifiable {
var id = UUID().uuidString
// both Image And Name Are Same....
var name: String
// since all Are Apple Native Apps...
var color: Int
var subText: String
var subText2: String
}
var searchItems = [
item(name: "Untitled (Skull)", color: 0, subText: "1983", subText2: "yay"),
item(name: "Dogs", color: 1, subText: "1972", subText2: "wow"),
item(name: "Cats", color: 2, subText: "1968", subText2: "oof")
]
struct Search_Bar: View {
#State var filteredItems = searchItems
var body: some View {
CustomNavigationView(view: AnyView(Home(filteredItems: $filteredItems)), placeHolder: "Museums, Art or anything else.", largeTitle: true, title: "Search",
onSearch: { (txt) in
if txt != ""{
self.filteredItems = searchItems.filter{$0.name.lowercased().contains(txt.lowercased())}
}
else{
self.filteredItems = searchItems
}
}, onCancel: {
// Do Your Own Code When Search And Canceled....
self.filteredItems = searchItems
})
.ignoresSafeArea()
}
}
struct Search_Bar_Previews: PreviewProvider {
static var previews: some View {
Search_Bar()
}
}
import SwiftUI
struct CustomNavigationView: UIViewControllerRepresentable {
func makeCoordinator() -> Coordinator {
return CustomNavigationView.Coordinator(parent: self)
}
// Just Change Your View That Requires Search Bar...
var view: AnyView
// Ease Of Use.....
var largeTitle: Bool
var title: String
var placeHolder: String
// onSearch And OnCancel Closures....
var onSearch: (String)->()
var onCancel: ()->()
// requre closure on Call...
init(view: AnyView,placeHolder: String? = "Search",largeTitle: Bool? = true,title: String,onSearch: #escaping (String)->(),onCancel: #escaping ()->()) {
self.title = title
self.largeTitle = largeTitle!
self.placeHolder = placeHolder!
self.view = view
self.onSearch = onSearch
self.onCancel = onCancel
}
// Integrating UIKit Navigation Controller With SwiftUI View...
func makeUIViewController(context: Context) -> UINavigationController {
// requires SwiftUI View...
let childView = UIHostingController(rootView: view)
let controller = UINavigationController(rootViewController: childView)
// Nav Bar Data...
controller.navigationBar.topItem?.title = title
controller.navigationBar.prefersLargeTitles = largeTitle
// search Bar....
let searchController = UISearchController()
searchController.searchBar.placeholder = placeHolder
// setting delegate...
searchController.searchBar.delegate = context.coordinator
// setting Search Bar In NavBar...
// disabling hide on scroll...
// disabling dim bg..
searchController.obscuresBackgroundDuringPresentation = false
controller.navigationBar.topItem?.hidesSearchBarWhenScrolling = false
controller.navigationBar.topItem?.searchController = searchController
return controller
}
func updateUIViewController(_ uiViewController: UINavigationController, context: Context) {
// Updating Real Time...
uiViewController.navigationBar.topItem?.title = title
uiViewController.navigationBar.topItem?.searchController?.searchBar.placeholder = placeHolder
uiViewController.navigationBar.prefersLargeTitles = largeTitle
}
// search Bar Delegate...
class Coordinator: NSObject,UISearchBarDelegate{
var parent: CustomNavigationView
init(parent: CustomNavigationView) {
self.parent = parent
}
func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
// when text changes....
self.parent.onSearch(searchText)
}
func searchBarCancelButtonClicked(_ searchBar: UISearchBar) {
// when cancel button is clicked...
self.parent.onCancel()
}
}
}
Letting the random view below for the array being for example:
import SwiftUI
struct cats: View {
var body: some View {
Text("cats") //replacing this with dogs or untitled skull as an example.
}
}
struct cats_Previews: PreviewProvider {
static var previews: some View {
cats()
}
}
You can use ForEach getting the item and its index in the closure :
ForEach(Array(filteredItems.enumerated()), id: \.1.id) { index, item in
NavigationLink(destination: views[index]){
Text(item.name)
}
}
For example :
struct ListItem: Identifiable {
let id = UUID()
let name: String
}
struct SwiftUIView17: View {
#State private var filteredItems = ["John", "Bob", "Maria"].map(ListItem.init)
let views = [AnyView(Text("John destination")), AnyView(Text("Bob destination")), AnyView(Text("Maria destination"))]
var body: some View {
ScrollView {
ForEach(Array(filteredItems.enumerated()), id: \.1.id) { index, item in
NavigationLink(destination: views[index]){
Text(item.name)
}
}
}
}
}
But it would be better not to use AnyView but a ViewBuilder :
struct SwiftUIView17: View {
#State private var filteredItems = ["John", "Bob", "Maria"].map(ListItem.init)
#ViewBuilder func destination(for itemIndex: Int) -> some View {
switch itemIndex {
case 0: Text("John destination")
case 1: Text("Bob destination").foregroundColor(.red)
case 2: Rectangle()
default: Text("error")
}
}
var body: some View {
ScrollView {
ForEach(Array(filteredItems.enumerated()), id: \.1.id) { index, item in
NavigationLink(destination: destination(for: index)){
Text(item.name)
}
}
}
}
}
I have the following model object that I use to populate a List with a Toggle for each row, which is bound to measurement.isSelected
final class Model: ObservableObject {
struct Measurement: Identifiable {
var id = UUID()
let name: String
var isSelected: Binding<Bool>
var selected: Bool = false
init(name: String) {
self.name = name
let selected = CurrentValueSubject<Bool, Never>(false)
self.isSelected = Binding<Bool>(get: { selected.value }, set: { selected.value = $0 })
}
}
#Published var measurements: [Measurement]
#Published var hasSelection: Bool = false // How to set this?
init(measurements: [Measurement]) {
self.measurements = measurements
}
}
I'd like the hasSelection property to be true whenever any measurement.isSelected is true. I'm guessing somehow Model needs to observe changes in measurements and then update its hasSelection property… but I've no idea where to start!
The idea is that hasSelection will be bound to a Button to enable or disable it.
Model is used as follows…
struct MeasurementsView: View {
#ObservedObject var model: Model
var body: some View {
NavigationView {
List(model.measurements) { measurement in
MeasurementView(measurement: measurement)
}
.navigationBarTitle("Select Measurements")
.navigationBarItems(trailing: NavigationLink(destination: NextView(), isActive: $model.hasSelection, label: {
Text("Next")
}))
}
}
}
struct MeasurementView: View {
let measurement: Model.Measurement
var body: some View {
HStack {
Text(measurement.name)
.font(.subheadline)
Spacer()
Toggle(measurement.name, isOn: measurement.isSelected)
.labelsHidden()
}
}
}
For info, here's a screenshot of what I'm trying to achieve. A list of selectable items, with a navigation link that is enabled when one or more is selected, and disabled when no items are selected.
#user3441734 hasSelection should ideally be a get only property, that
is true if any of measurement.isSelected is true
struct Data {
var bool: Bool
}
class Model: ObservableObject {
#Published var arr: [Data] = []
var anyTrue: Bool {
arr.map{$0.bool}.contains(true)
}
}
example (as before) copy - paste - run
import SwiftUI
struct Data: Identifiable {
let id = UUID()
var name: String
var on_off: Bool
}
class Model: ObservableObject {
#Published var data = [Data(name: "alfa", on_off: false), Data(name: "beta", on_off: false), Data(name: "gama", on_off: false)]
var bool: Bool {
data.map {$0.on_off} .contains(true)
}
}
struct ContentView: View {
#ObservedObject var model = Model()
var body: some View {
VStack {
List(0 ..< model.data.count) { idx in
HStack {
Text(verbatim: self.model.data[idx].name)
Toggle(isOn: self.$model.data[idx].on_off) {
EmptyView()
}
}
}
Text("\(model.bool.description)").font(.largeTitle).padding()
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
When the model.data is updated
#Published var data ....
its publisher calls objectWillChange on ObservableObject.
Next SwiftUI recognize that ObservedObject needs the View to be "updated". The View is recreated, and that will force the model.bool.description will have fresh value.
LAST UPDATE
change this part of code
struct ContentView: View {
#ObservedObject var model = Model()
var body: some View {
NavigationView {
List(0 ..< model.data.count) { idx in
HStack {
Text(verbatim: self.model.data[idx].name)
Toggle(isOn: self.$model.data[idx].on_off) {
EmptyView()
}
}
}.navigationBarTitle("List")
.navigationBarItems(trailing:
NavigationLink(destination: Text("next"), label: {
Text("Next")
}).disabled(!model.bool)
)
}
}
}
and it is EXACTLY, WHAT YOU HAVE in your updated question
Try it on real device, otherwise the NavigationLink is usable only once (this is well known simulator bug in current Xcode 11.3.1 (11C504)).
The problem with your code at the moment is that even if you observe the changes to measurements, they will not get updated when the selection updates, because you declared the var isSelected: Binding<Bool> as a Binding. This means that SwiftUI is storing it outside of your struct, and the struct itself doesn't update (stays immutable).
What you could try instead is declaring #Published var selectedMeasurementId: UUID? = nil on your model So your code would be something like this:
import SwiftUI
import Combine
struct NextView: View {
var body: some View {
Text("Next View")
}
}
struct MeasurementsView: View {
#ObservedObject var model: Model
var body: some View {
let hasSelection = Binding<Bool> (
get: {
self.model.selectedMeasurementId != nil
},
set: { value in
self.model.selectedMeasurementId = nil
}
)
return NavigationView {
List(model.measurements) { measurement in
MeasurementView(measurement: measurement, selectedMeasurementId: self.$model.selectedMeasurementId)
}
.navigationBarTitle("Select Measurements")
.navigationBarItems(trailing: NavigationLink(destination: NextView(), isActive: hasSelection, label: {
Text("Next")
}))
}
}
}
struct MeasurementView: View {
let measurement: Model.Measurement
#Binding var selectedMeasurementId: UUID?
var body: some View {
let isSelected = Binding<Bool>(
get: {
self.selectedMeasurementId == self.measurement.id
},
set: { value in
if value {
self.selectedMeasurementId = self.measurement.id
} else {
self.selectedMeasurementId = nil
}
}
)
return HStack {
Text(measurement.name)
.font(.subheadline)
Spacer()
Toggle(measurement.name, isOn: isSelected)
.labelsHidden()
}
}
}
final class Model: ObservableObject {
#Published var selectedMeasurementId: UUID? = nil
struct Measurement: Identifiable {
var id = UUID()
let name: String
init(name: String) {
self.name = name
}
}
#Published var measurements: [Measurement]
init(measurements: [Measurement]) {
self.measurements = measurements
}
}
I'm not sure exactly how you want the navigation button in the navbar to behave. For now I just set the selection to nil when it's tapped. You can modify it depending on what you want to do.
If you want to support multi-selection, you can use a Set of selected ids instead.
Also, seems like the iOS simulator has some problems with navigation, but I tested on a physical device and it worked.
Im trying to create an environment object that is editable and putting it in a list.
The Variables are only refreshing when I switch the tab for example (so whenever I leave the NavigationView) and then come back.
The same worked with a ModalView before. Is it a bug maybe? Or am I doing something wrong?
import SwiftUI
import Combine
struct TestView: View {
#State var showSheet: Bool = false
#EnvironmentObject var feed: TestObject
func addObjects() {
var strings = ["one","two","three","four","five","six"]
for s in strings {
var testItem = TestItem(text: s)
self.feed.items.append(testItem)
}
}
var body: some View {
TabView {
NavigationView {
List(feed.items.indices, id:\.self) { i in
NavigationLink(destination: detailView(feed: self._feed, i: i)) {
HStack {
Text(self.feed.items[i].text)
Text("(\(self.feed.items[i].read.description))")
}
}
}
}
.tabItem({ Text("Test") })
.tag(0)
Text("Blank")
.tabItem({ Text("Test") })
.tag(0)
}.onAppear {
self.addObjects()
}
}
}
struct detailView: View {
#EnvironmentObject var feed: TestObject
var i: Int
var body: some View {
VStack {
Text(feed.items[i].text)
Text(feed.items[i].read.description)
Button(action: { self.feed.items[self.i].isRead.toggle() }) {
Text("Toggle read")
}
}
}
}
final class TestItem: ObservableObject {
init(text: String) {
self.text = text
self.isRead = false
}
static func == (lhs: TestItem, rhs: TestItem) -> Bool {
lhs.text < rhs.text
}
var text: String
var isRead: Bool
let willChange = PassthroughSubject<TestItem, Never>()
var read: Bool {
set {
self.isRead = newValue
}
get {
self.isRead
}
}
}
class TestObject: ObservableObject {
var willChange = PassthroughSubject<TestObject, Never>()
#Published var items: [TestItem] = [] {
didSet {
willChange.send(self)
}
}
}
try passing .environmentObject on your destination:
NavigationLink(destination: detailView(feed: self._feed, i: i).environmentObject(x))
You have to use willSet instead of didSet.
TestItem should be a value type: struct or enum. SwiftUI's observation system properly works only with value types.
Ím trying to refresh this List whenever I click on a NavLink
NavigationView {
List(feed.items.indices, id:\.self) { i in
NavigationLink(destination: ListFeedItemDetail(idx: i).environmentObject(self.feed)) {
ListFeedItem(item: self.$feed.items[i])
}
}
}
The list is made out of an array inside an environment object.
The problem: It does only refresh when I switch to another tab or close the app
I had used a modal View before and it worked there. (I did it with .onAppear)
Any Ideas?
Example
Problem: When you tap on an item in the list and tap the toggle button the EnvironmentObject is changed but this changed is only reflected when I change the tab and change it back again
import SwiftUI
import Combine
struct TestView: View {
#State var showSheet: Bool = false
#EnvironmentObject var feed: TestObject
func addObjects() {
var strings = ["one","two","three","four","five","six"]
for s in strings {
var testItem = TestItem(text: s)
self.feed.items.append(testItem)
}
}
var body: some View {
TabView {
NavigationView {
List(feed.items.indices, id:\.self) { i in
NavigationLink(destination: detailView(feed: self._feed, i: i)) {
HStack {
Text(self.feed.items[i].text)
Text("(\(self.feed.items[i].read.description))")
}
}
}
}
.tabItem({ Text("Test") })
.tag(0)
Text("Blank")
.tabItem({ Text("Test") })
.tag(0)
}.onAppear {
self.addObjects()
}
}
}
struct detailView: View {
#EnvironmentObject var feed: TestObject
var i: Int
var body: some View {
VStack {
Text(feed.items[i].text)
Text(feed.items[i].read.description)
Button(action: { self.feed.items[self.i].isRead.toggle() }) {
Text("Toggle read")
}
}
}
}
final class TestItem: ObservableObject {
init(text: String) {
self.text = text
self.isRead = false
}
static func == (lhs: TestItem, rhs: TestItem) -> Bool {
lhs.text < rhs.text
}
var text: String
var isRead: Bool
let willChange = PassthroughSubject<TestItem, Never>()
var read: Bool {
set {
self.isRead = newValue
}
get {
self.isRead
}
}
}
class TestObject: ObservableObject {
var willChange = PassthroughSubject<TestObject, Never>()
#Published var items: [TestItem] = [] {
didSet {
willChange.send(self)
}
}
}
I had a similar problem, this is the hack I came up with.
In your "TestView" declare:
#State var needRefresh: Bool = false
Pass this to your "detailView" destination, such as:
NavigationLink(destination: detailView(feed: self._feed, i: i, needRefresh: self.$needRefresh)) {
HStack {
Text(self.feed.items[i].text)
Text("(\(self.feed.items[i].read.description))")
}.accentColor(self.needRefresh ? .white : .black)
}
Note ".accentColor(self.needRefresh ? .white : .black)" to force a refresh when "needRefresh"
is changed.
In your "detailView" destination add:
#Binding var needRefresh: Bool
Then in your "detailView" in your Button action, add:
self.needRefresh.toggle()