I have a situation where I have a view model with a #Published value. Now when I'm building the UI I want to send a value via a preference every time the published value changes. The problem I'm having is that I cannot figure out how to get SwiftUI to watch the published value and send the preference.
In the code below I've endeavoured to simplify the problem.
Preference key:
struct NewValueKey: PreferenceKey {
static var defaultValue: String? = nil
static func reduce(value: inout String?, nextValue: () -> String) {
value = nextValue()
}
}
Publishing object:
public class SomeViewModel: ObservableObject {
#Published public var value: String?
}
And in the Swift UI view:
.onReceive(viewModel.$value) { _ in
let newValue = "abc"
Color.clear.preference(key: NewValueKey.self, value: newValue)
}
But I get a variety of errors such as the result of the preference not being used, etc. The problem is that I need to execute some code to build the value I want to send so I can't just forward the value I receive. I've also looked at using a #State property as some sort of intermediary but I'm not sure how to wire it all together.
Any suggestions?
It is enough to inject value directly into preference modifier attached to a view within modified context (ie. you don't need .onReceive modifer because updated value will activate .preference modifier directly).
Tested with Xcode 13.3 / iOS 15.4
Here is a snapshot of main part
Button("Generate") {
vm.value = String(Int.random(in: 0...9))
}
.preference(key: NewValueKey.self, value: vm.value) // << here !!
Completed findings report and code is here
not clear what you want, but ensure that you have something like this in your view, or equivalent #ObservedObject:
#StateObject var viewModel = SomeViewModel()
Also:
struct NewValueKey: PreferenceKey {
static var defaultValue: String = "" // <-- here
static func reduce(value: inout String, nextValue: () -> String) { // <-- here
value = nextValue()
}
}
and to get rid of the warning:
.onReceive(viewModel.$value) { _ in
let newValue = "abc"
let _ = Color.clear.preference(key: NewValueKey.self, value: newValue) // <-- here
}
or
.onReceive(viewModel.$value) { val in
if let newValue = val {
let _ = Color.clear.preference(key: NewValueKey.self, value: newValue) // <-- here
}
}
Related
I have a fairly complex document type to work with. It is basically a bundle containing a set of independent documents of the same type, with various pieces of metadata about the documents. The data structure that represents the bundle is an array of structs, similar to this (there are several more fields, but these are representative):
struct DocumentData: Equatable, Identifiable, Hashable {
let id = UUID()
var docData: DocumentDataClass
var docName: String
var docFileWrapper: FileWrapper?
func hash(into hasher: inout Hasher) {
id.hash(into: &hasher)
}
static func ==(lhs: KeyboardLayoutData, rhs: KeyboardLayoutData) -> Bool {
return lhs.id == rhs.id
}
}
The window for the bundle is a master-detail, with a list on the left and, when one is selected, there is an edit pane for the document on the right. The FileWrapper is used to keep track of which files need to be written for saving, so it gets initialised on reading the relevant file, and reset when an undoable change is made. That is largely the only way that the DocumentData structure gets changed (ignoring explicit things like changing the name).
I've reached a point where a lot of things are working, but I'm stuck on one. There's a view inside the edit pane, several levels deep, and when I double-click it, I want a sheet to appear. It does so, but then disappears by itself.
Searching for ways to work this out, I discovered by using print(Self._printChanges()) at various points that the edit pane was being refreshed after showing the sheet, which meant that the parent disappeared. What I found was that the dependency that changed was the DocumentData instance. But, I then added a print of the DocumentData instance before the _printChanges call, and it is identical. I have also put in didSet for each field of DocumentData to print when they get set, and nothing gets printed, so I'm not sure where the change is happening.
So the question comes down to how I can work out what is actually driving the refresh, since what is claimed to be different is identical in every field.
There are some other weird things happening, such as dragging and dropping text into the view causing the whole top-level document array of DocumentData items to change before the drop gets processed and the data structures get updated, so there are things I am not understanding as clearly as I might like. Any guidance is much appreciated.
ADDED:
The view that triggers the sheet is fairly straightforward, especially compared to its enclosing view, which is where most of the interface code is. This is a slightly simplified version of it:
struct MyView: View, DropDelegate {
#EnvironmentObject var keyboardStatus: KeyboardStatus
#Environment(\.displayFont) var displayFont
#Environment(\.undoManager) var undoManager
var keyCode: Int
#State var modifiers: NSEvent.ModifierFlags = []
#State private var dragHighlight = false
#State private var activeSheet: ActiveSheet?
#State private var editPopoverIsPresented = false
// State variables for double click and drop handling
...
static let dropTypes = [UTType.utf8PlainText]
var body: some View {
ZStack {
BackgroundView(...)
Text(...)
}
.onAppear {
modifiers = keyboardStatus.currentModifiers
}
.focusable(false)
.allowsHitTesting(true)
.contentShape(geometry.contentPath)
.onHover { entered in
// updates an inspector view
}
.onTapGesture(count: 2) {
interactionType = .doubleClick
activeSheet = .doubleClick
}
.onTapGesture(count: 1) {
handleItemClick()
}
.sheet(item: $activeSheet, onDismiss: handleSheetReturn) { item in
switch item {
case .doubleClick:
DoubleClickItem(...) ) {
activeSheet = nil
}
case .drop:
DropItem(...) {
activeSheet = nil
}
}
}
.popover(isPresented: $editPopoverIsPresented) {
EditPopup(...)
}
.onDrop(of: KeyCap.dropTypes, delegate: self)
.contextMenu {
ItemContextMenu(...)
}
}
func handleItemClick() {
NotificationCenter.default.post(name: .itemClick, object: nil, userInfo: [...])
}
func handleEvent(event: KeyEvent) {
if event.eventKind == .dropText {
interactionType = .drop
activeSheet = .drop
}
else if event.eventKind == .replaceText {
...
handleItemDoubleClick()
}
}
func handleSheetReturn() {
switch interactionType {
case .doubleClick:
handleItemDoubleClick()
case .drop:
handleItemDrop()
case .none:
break
}
}
func handleItemDoubleClick() {
switch itemAction {
case .state1:
...
case .state2:
...
case .none:
// User cancelled
break
}
interactionType = nil
}
func handleItemDrop() {
switch itemDropAction {
case .action1:
...
case .action2:
...
case .none:
// User cancelled
break
}
interactionType = nil
}
// Drop delegate
func dropEntered(info: DropInfo) {
dragHighlight = true
}
func dropExited(info: DropInfo) {
dragHighlight = false
}
func performDrop(info: DropInfo) -> Bool {
if let item = info.itemProviders(for: MyView.dropTypes).first {
item.loadItem(forTypeIdentifier: UTType.utf8PlainText.identifier, options: nil) { (textData, error) in
if let textData = String(data: textData as! Data, encoding: .utf8) {
let event = ...
handleEvent(event: event)
}
}
return true
}
return false
}
}
Further edit:
I ended up rewiring the code so that the sheet belongs to the higher level view, which makes everything work without solving the question. I still don't understand why I get a notification that a dependency has changed when it is identical to what it was before, and none of the struct's didSet blocks are called.
Try removing the class from the DocumentData. The use of objects in SwiftUI can cause these kind of bugs since it’s all designed for value types.
Try using ReferenceFileDocument to work with your model object instead of FileDocument which is designed for a model of value types.
Try using sheet(item:onDismiss:content:) for editing. I've seen people have the problem you describe when they try to hack the boolean sheet to work with editing an item.
I have a form where the user enters their address. While they can always enter it manually, I also wanted to provide them with an easy solution with auto complete so that they could just start typing their address and then tap on the correct one from the list and have it auto populate the various fields.
I started by working off of jnpdx's Swift5 solution - https://stackoverflow.com/a/67131376/11053343
However, there are two issues that I cannot seem to solve:
I need the results to be limited to the United States only (not just the continental US, but the entire United States including Alaska, Hawaii, and Puerto Rico). I am aware of how MKCoordinateRegion works with the center point and then the zoom spread, but it doesn't seem to work on the results of the address search.
The return of the results provides only a title and subtitle, where I need to actually extract all the individual address information and populate my variables (i.e. address, city, state, zip, and zip ext). If the user has an apt or suite number, they would then fill that in themselves. My thought was to create a function that would run when the button is tapped, so that the variables are assigned based off of the user's selection, but I have no idea how to extract the various information required. Apple's docs are terrible as usual and I haven't found any tutorials explaining how to do this.
This is for the latest SwiftUI and XCode (ios15+).
I created a dummy form for testing. Here's what I have:
import SwiftUI
import Combine
import MapKit
class MapSearch : NSObject, ObservableObject {
#Published var locationResults : [MKLocalSearchCompletion] = []
#Published var searchTerm = ""
private var cancellables : Set<AnyCancellable> = []
private var searchCompleter = MKLocalSearchCompleter()
private var currentPromise : ((Result<[MKLocalSearchCompletion], Error>) -> Void)?
override init() {
super.init()
searchCompleter.delegate = self
searchCompleter.region = MKCoordinateRegion()
searchCompleter.resultTypes = MKLocalSearchCompleter.ResultType([.address])
$searchTerm
.debounce(for: .seconds(0.5), scheduler: RunLoop.main)
.removeDuplicates()
.flatMap({ (currentSearchTerm) in
self.searchTermToResults(searchTerm: currentSearchTerm)
})
.sink(receiveCompletion: { (completion) in
//handle error
}, receiveValue: { (results) in
self.locationResults = results
})
.store(in: &cancellables)
}
func searchTermToResults(searchTerm: String) -> Future<[MKLocalSearchCompletion], Error> {
Future { promise in
self.searchCompleter.queryFragment = searchTerm
self.currentPromise = promise
}
}
}
extension MapSearch : MKLocalSearchCompleterDelegate {
func completerDidUpdateResults(_ completer: MKLocalSearchCompleter) {
currentPromise?(.success(completer.results))
}
func completer(_ completer: MKLocalSearchCompleter, didFailWithError error: Error) {
//currentPromise?(.failure(error))
}
}
struct MapKit_Interface: View {
#StateObject private var mapSearch = MapSearch()
#State private var address = ""
#State private var addrNum = ""
#State private var city = ""
#State private var state = ""
#State private var zip = ""
#State private var zipExt = ""
var body: some View {
List {
Section {
TextField("Search", text: $mapSearch.searchTerm)
ForEach(mapSearch.locationResults, id: \.self) { location in
Button {
// Function code goes here
} label: {
VStack(alignment: .leading) {
Text(location.title)
.foregroundColor(Color.white)
Text(location.subtitle)
.font(.system(.caption))
.foregroundColor(Color.white)
}
} // End Label
} // End ForEach
} // End Section
Section {
TextField("Address", text: $address)
TextField("Apt/Suite", text: $addrNum)
TextField("City", text: $city)
TextField("State", text: $state)
TextField("Zip", text: $zip)
TextField("Zip-Ext", text: $zipExt)
} // End Section
} // End List
} // End var Body
} // End Struct
Since no one has responded, I, and my friend Tolstoy, spent a lot of time figuring out the solution and I thought I would post it for anyone else who might be interested. Tolstoy wrote a version for the Mac, while I wrote the iOS version shown here.
Seeing as how Google is charging for usage of their API and Apple is not, this solution gives you address auto-complete for forms. Bear in mind it won't always be perfect because we are beholden to Apple and their maps. Likewise, you have to turn the address into coordinates, which you then turn into a placemark, which means there will be some addresses that may change when tapped from the completion list. Odds are this won't be an issue for 99.9% of users, but thought I would mention it.
At the time of this writing, I am using XCode 13.2.1 and SwiftUI for iOS 15.
I organized it with two Swift files. One to hold the class/struct (AddrStruct.swift) and the other which is the actual view in the app.
AddrStruct.swift
import SwiftUI
import Combine
import MapKit
import CoreLocation
class MapSearch : NSObject, ObservableObject {
#Published var locationResults : [MKLocalSearchCompletion] = []
#Published var searchTerm = ""
private var cancellables : Set<AnyCancellable> = []
private var searchCompleter = MKLocalSearchCompleter()
private var currentPromise : ((Result<[MKLocalSearchCompletion], Error>) -> Void)?
override init() {
super.init()
searchCompleter.delegate = self
searchCompleter.resultTypes = MKLocalSearchCompleter.ResultType([.address])
$searchTerm
.debounce(for: .seconds(0.2), scheduler: RunLoop.main)
.removeDuplicates()
.flatMap({ (currentSearchTerm) in
self.searchTermToResults(searchTerm: currentSearchTerm)
})
.sink(receiveCompletion: { (completion) in
//handle error
}, receiveValue: { (results) in
self.locationResults = results.filter { $0.subtitle.contains("United States") } // This parses the subtitle to show only results that have United States as the country. You could change this text to be Germany or Brazil and only show results from those countries.
})
.store(in: &cancellables)
}
func searchTermToResults(searchTerm: String) -> Future<[MKLocalSearchCompletion], Error> {
Future { promise in
self.searchCompleter.queryFragment = searchTerm
self.currentPromise = promise
}
}
}
extension MapSearch : MKLocalSearchCompleterDelegate {
func completerDidUpdateResults(_ completer: MKLocalSearchCompleter) {
currentPromise?(.success(completer.results))
}
func completer(_ completer: MKLocalSearchCompleter, didFailWithError error: Error) {
//could deal with the error here, but beware that it will finish the Combine publisher stream
//currentPromise?(.failure(error))
}
}
struct ReversedGeoLocation {
let streetNumber: String // eg. 1
let streetName: String // eg. Infinite Loop
let city: String // eg. Cupertino
let state: String // eg. CA
let zipCode: String // eg. 95014
let country: String // eg. United States
let isoCountryCode: String // eg. US
var formattedAddress: String {
return """
\(streetNumber) \(streetName),
\(city), \(state) \(zipCode)
\(country)
"""
}
// Handle optionals as needed
init(with placemark: CLPlacemark) {
self.streetName = placemark.thoroughfare ?? ""
self.streetNumber = placemark.subThoroughfare ?? ""
self.city = placemark.locality ?? ""
self.state = placemark.administrativeArea ?? ""
self.zipCode = placemark.postalCode ?? ""
self.country = placemark.country ?? ""
self.isoCountryCode = placemark.isoCountryCode ?? ""
}
}
For testing purposes, I called my main view file Test.swift. Here's a stripped down version for reference.
Test.swift
import SwiftUI
import Combine
import CoreLocation
import MapKit
struct Test: View {
#StateObject private var mapSearch = MapSearch()
func reverseGeo(location: MKLocalSearchCompletion) {
let searchRequest = MKLocalSearch.Request(completion: location)
let search = MKLocalSearch(request: searchRequest)
var coordinateK : CLLocationCoordinate2D?
search.start { (response, error) in
if error == nil, let coordinate = response?.mapItems.first?.placemark.coordinate {
coordinateK = coordinate
}
if let c = coordinateK {
let location = CLLocation(latitude: c.latitude, longitude: c.longitude)
CLGeocoder().reverseGeocodeLocation(location) { placemarks, error in
guard let placemark = placemarks?.first else {
let errorString = error?.localizedDescription ?? "Unexpected Error"
print("Unable to reverse geocode the given location. Error: \(errorString)")
return
}
let reversedGeoLocation = ReversedGeoLocation(with: placemark)
address = "\(reversedGeoLocation.streetNumber) \(reversedGeoLocation.streetName)"
city = "\(reversedGeoLocation.city)"
state = "\(reversedGeoLocation.state)"
zip = "\(reversedGeoLocation.zipCode)"
mapSearch.searchTerm = address
isFocused = false
}
}
}
}
// Form Variables
#FocusState private var isFocused: Bool
#State private var btnHover = false
#State private var isBtnActive = false
#State private var address = ""
#State private var city = ""
#State private var state = ""
#State private var zip = ""
// Main UI
var body: some View {
VStack {
List {
Section {
Text("Start typing your street address and you will see a list of possible matches.")
} // End Section
Section {
TextField("Address", text: $mapSearch.searchTerm)
// Show auto-complete results
if address != mapSearch.searchTerm && isFocused == false {
ForEach(mapSearch.locationResults, id: \.self) { location in
Button {
reverseGeo(location: location)
} label: {
VStack(alignment: .leading) {
Text(location.title)
.foregroundColor(Color.white)
Text(location.subtitle)
.font(.system(.caption))
.foregroundColor(Color.white)
}
} // End Label
} // End ForEach
} // End if
// End show auto-complete results
TextField("City", text: $city)
TextField("State", text: $state)
TextField("Zip", text: $zip)
} // End Section
.listRowSeparator(.visible)
} // End List
} // End Main VStack
} // End Var Body
} // End Struct
struct Test_Previews: PreviewProvider {
static var previews: some View {
Test()
}
}
If anyone is wondering how to generate global results, change the code from this:
self.locationResults = results.filter{$0.subtitle.contains("United States")}
to this in Address Structure file:
self.locationResults = results
To provide some context, Im writing an order tracking section of our app, which reloads the order status from the server every so-often. The UI on-screen is developed in SwiftUI. I require an optional image on screen that changes as the order progresses through the statuses.
When I try the following everything works...
My viewModel is an ObservableObject:
internal class MyAccountOrderViewModel: ObservableObject {
This has a published property:
#Published internal var graphicURL: URL = Bundle.main.url(forResource: "tracking_STAGEONE", withExtension: "gif")!
In SwiftUI use the property as follows:
GIFViewer(imageURL: $viewModel.graphicURL)
My issue is that the graphicURL property has a potentially incorrect placeholder value, and my requirements were that it was optional. Changing the published property to: #Published internal var graphicURL: URL? causes an issue for my GIFViewer which rightly does not accept an optional URL:
Cannot convert value of type 'Binding<URL?>' to expected argument type 'Binding<URL>'
Attempting the obvious unwrapping of graphicURL produces this error:
Cannot force unwrap value of non-optional type 'Binding<URL?>'
What is the right way to make this work? I don't want to have to put a value in the property, and check if the property equals placeholder value (Ie treat that as if it was nil), or assume the property is always non-nil and unsafely force unwrap it somehow.
Below is an extension of Binding you can use to convert a type like Binding<Int?> to Binding<Int>?. In your case, it would be URL instead of Int, but this extension is generic so will work with any Binding:
extension Binding {
func optionalBinding<T>() -> Binding<T>? where T? == Value {
if let wrappedValue = wrappedValue {
return Binding<T>(
get: { wrappedValue },
set: { self.wrappedValue = $0 }
)
} else {
return nil
}
}
}
With example view:
struct ContentView: View {
#StateObject private var model = MyModel()
var body: some View {
VStack(spacing: 30) {
Button("Toggle if nil") {
if model.counter == nil {
model.counter = 0
} else {
model.counter = nil
}
}
if let binding = $model.counter.optionalBinding() {
Stepper(String(binding.wrappedValue), value: binding)
} else {
Text("Counter is nil")
}
}
}
}
class MyModel: ObservableObject {
#Published var counter: Int?
}
Result:
I have created a class to perform a network request and parse the data using Combine. I'm not entirely certain the code is correct, but it's working as of now (still learning the basics of Swift and basic networking tasks). My Widget has the correct data and is works until the data becomes nil. Unsure how to check if the data from my first publisher in my SwiftUI View is nil, the data seems to be valid even when there's no games showing.
My SwiftUI View
struct SimpleEntry: TimelineEntry {
let date: Date
public var model: CombineData?
let configuration: ConfigurationIntent
}
struct Some_WidgetEntryView : View {
var entry: Provider.Entry
#Environment(\.widgetFamily) var widgetFamily
var body: some View {
VStack (spacing: 0){
if entry.model?.schedule?.dates.first?.games == nil {
Text("No games Scheduled")
} else {
Text("Game is scheduled")
}
}
}
}
Combine
import Foundation
import WidgetKit
import Combine
// MARK: - Combine Attempt
class CombineData {
var schedule: Schedule?
var live: Live?
private var cancellables = Set<AnyCancellable>()
func fetchSchedule(_ teamID: Int, _ completion: #escaping (Live) -> Void) {
let url = URL(string: "https://statsapi.web.nhl.com/api/v1/schedule?teamId=\(teamID)")!
let publisher = URLSession.shared.dataTaskPublisher(for: url)
.map(\.data)
.decode(type: Schedule.self, decoder: JSONDecoder())
//.catch { _ in Empty<Schedule, Error>() }
//.replaceError(with: Schedule(dates: []))
let publisher2 = publisher
.flatMap {
return self.fetchLiveFeed($0.dates.first?.games.first?.link ?? "")
}
Publishers.Zip(publisher, publisher2)
.receive(on: DispatchQueue.main)
.sink(receiveCompletion: {_ in
}, receiveValue: { schedule, live in
self.schedule = schedule
self.live = live
completion(self.live!)
WidgetCenter.shared.reloadTimelines(ofKind: "NHL_Widget")
}).store(in: &cancellables)
}
func fetchLiveFeed(_ link: String) -> AnyPublisher<Live, Error /*Never if .catch error */> {
let url = URL(string: "https://statsapi.web.nhl.com\(link)")!
return URLSession.shared.dataTaskPublisher(for: url)
.map(\.data)
.decode(type: Live.self, decoder: JSONDecoder())
//.catch { _ in Empty<Live, Never>() }
.eraseToAnyPublisher()
}
}
Like I said in the comments, it's likely that the decode(type: Live.self, decoder: JSONDecoder()) returns an error because the URL that you're fetching from when link is nil doesn't return anything that can be decoded as Live.self.
So you need to handle that case somehow. For example, you can handle this by making the Live variable an optional, and returning nil when link is empty (or nil).
This is just to set you in the right direction - you'll need to work out the exact code yourself.
let publisher2 = publisher1
.flatMap {
self.fetchLiveFeed($0.dates.first?.games.first?.link ?? "")
.map { $0 as Live? } // convert to an optional
.replaceError(with: nil)
}
Then in the sink, handle the nil:
.sink(receiveCompletion: {_ in }, receiveValue:
{ schedule, live in
if let live = live {
// normal treatment
self.schedule = schedule
self.live = live
//.. etc
} else {
// set a placeholder
}
})
SwiftUI and WidgetKit work differently. I needed to fetch data in getTimeline for my IntentTimelineProvider then add a completion handler for my TimelineEntry. Heavily modified my Combine data model. All credit goes to #EmilioPelaez for pointing me in the right direction, answer here.
Can SwiftUI Text Fields work with optional Bindings? Currently this code:
struct SOTestView : View {
#State var test: String? = "Test"
var body: some View {
TextField($test)
}
}
produces the following error:
Cannot convert value of type 'Binding< String?>' to expected argument type 'Binding< String>'
Is there any way around this? Using Optionals in data models is a very common pattern - in fact it's the default in Core Data so it seems strange that SwiftUI wouldn't support them
You can add this operator overload, then it works as naturally as if it wasn't a Binding.
func ??<T>(lhs: Binding<Optional<T>>, rhs: T) -> Binding<T> {
Binding(
get: { lhs.wrappedValue ?? rhs },
set: { lhs.wrappedValue = $0 }
)
}
This creates a Binding that returns the left side of the operator's value if it's not nil, otherwise it returns the default value from the right side.
When setting it only sets lhs value, and ignores anything to do with the right hand side.
It can be used like this:
TextField("", text: $test ?? "default value")
Ultimately the API doesn't allow this - but there is a very simple and versatile workaround:
extension Optional where Wrapped == String {
var _bound: String? {
get {
return self
}
set {
self = newValue
}
}
public var bound: String {
get {
return _bound ?? ""
}
set {
_bound = newValue.isEmpty ? nil : newValue
}
}
}
This allows you to keep the optional while making it compatible with Bindings:
TextField($test.bound)
True, at the moment TextField in SwiftUI can only be bound to String variables, not String?.
But you can always define your own Binding like so:
import SwiftUI
struct SOTest: View {
#State var text: String?
var textBinding: Binding<String> {
Binding<String>(
get: {
return self.text ?? ""
},
set: { newString in
self.text = newString
})
}
var body: some View {
TextField("Enter a string", text: textBinding)
}
}
Basically, you bind the TextField text value to this new Binding<String> binding, and the binding redirects it to your String? #State variable.
I prefer the answer provided by #Jonathon. as it is simple and elegant and provides the coder with an insitu base case when the Optional is .none (= nil) and not .some.
However I feel it is worth adding in my two cents here. I learned this technique from reading Jim Dovey's blog on SwiftUI Bindings with Core Data. Its essentially the same answer provided by #Jonathon. but does include a nice pattern that can be replicated for a number of different data types.
First create an extension on Binding
public extension Binding where Value: Equatable {
init(_ source: Binding<Value?>, replacingNilWith nilProxy: Value) {
self.init(
get: { source.wrappedValue ?? nilProxy },
set: { newValue in
if newValue == nilProxy { source.wrappedValue = nil }
else { source.wrappedValue = newValue }
}
)
}
}
Then use in your code like this...
TextField("", text: Binding($test, replacingNilWith: String()))
or
TextField("", text: Binding($test, replacingNilWith: ""))
Try this works for me with reusable function
#State private var name: String? = nil
private func optionalBinding<T>(val: Binding<T?>, defaultVal: T)-> Binding<T>{
Binding<T>(
get: {
return val.wrappedValue ?? defaultVal
},
set: { newVal in
val.wrappedValue = newVal
}
)
}
// Usage
TextField("", text: optionalBinding(val: $name, defaultVal: ""))