Make updated Int stay the same in a new struct - swiftui

I have a button that adds + 1 to an Int. I want to be able to access the value of the Int in another struct. Right now I am available to access the Int, but it starts from zero, not showing the amount of + 1 added after pressing the button in the previous struct.
Is there a way to "remember" the Ints that are added?
import SwiftUI
class NumberOrder: ObservableObject {
#Published var Number: Int = 0
}
struct Choose: View {
#State var buttonClick: Bool = false
#StateObject var numbeorder = NumberOrder()
var body: some View {
ZStack {
Color.black
VStack{
Text("\(numbeorder.Number)")
.font(.system(size: 50))
Button {
buttonClick.toggle()
} label: {
Image(systemName: "arrow.left.circle")
.foregroundColor(.white)
.font(.system(size: 50))
}
Button {
self.numbeorder.Number += 1
} label: {
Text("ADD ONE")
.font(.system(size: 40, weight: .medium))
}
}
if buttonClick == true {
Feeling1()
}
}
}
}
struct Choose_Previews: PreviewProvider {
static var previews: some View {
Choose()
}
}
struct Feeling1: View {
#State var goBack0: Bool = false
#StateObject var numbeorder = NumberOrder()
var body: some View {
ZStack {
Color.purple
Text("\(numbeorder.Number)")
.font(.system(size: 50))
Button {
goBack0.toggle()
} label: {
Image(systemName: "arrow.left.circle")
.foregroundColor(.black)
.font(.system(size: 50))
}.buttonStyle(.plain)
.padding(.init(top: -250, leading: 0, bottom: 0, trailing: 150))
if goBack0 == true {
Choose()
}
}
}
}

You have 2 different #StateObject var numbeorder = NumberOrder() that have no relations to each other.
Have a look at this link, it gives you some good examples of how to manage data in your app :
https://developer.apple.com/documentation/swiftui/managing-model-data-in-your-app
Note, you should use the common practice to name your vars in lower case, particularly Number,
in NumberOrder, as Swift has already a Number.
So, in Feeling1, use #ObservedObject var numbeorder: NumberOrder
and use Feeling1(numbeorder: numbeorder) in Choose

Use let for read access or #Binding var for write access, e.g.
struct Feeling1: View {
// let goBack0: Bool // if only need read access
#Binding var goBack0: Bool // if need read and write access
Note: don't use #StateObject unless you need a reference type instead of an #State struct which doesn't appear to be the case here, e.g.
struct NumberOrder {
var number: Int = 0
// mutating func someLogic() { }
}
#State var order = NumberOrder()

Related

How to set up Textfield and Button in Custom SwiftUI View

I am attempting the configure the text field and button in my openweathermap app to be in its own view other than the main content view. In TextFieldView, the action of the button is set up to call an API response. Then, the weather data from the response is populated on a sheet-based DetailView, which is triggered by the button in TextFieldView. I configured the ForEach method in the sheet to return the last city added to the WeatherModel array (which would technically be the most recent city entered into the text field), then populate the sheet-based DetailView with weather data for that city. Previously, When I had the HStack containing the text field, button, and sheet control set up in the ContentView, the Sheet would properly display weather for the city that had just entered into the text field. After moving those items to a separate TextFieldView, the ForEach method appears to have stopped working. Instead, the weather info returned after entering a city name into the text field is displayed on the wrong count. For instance, if I were to enter "London" in the text field, the DetailView in the sheet is completely blank. If I then enter "Rome" as the next entry, the DetailView in the sheet shows weather info for the previous "London" entry. Entering "Paris" in the textfield displays weather info for "Rome", and so on...
To summarize, the ForEach method in the sheet stopped working properly after I moved the whole textfield and button feature to a separate view. Any idea why the issue I described is happening?
Here is my code:
ContentView
struct ContentView: View {
// Whenever something in the viewmodel changes, the content view will know to update the UI related elements
#StateObject var viewModel = WeatherViewModel()
var body: some View {
NavigationView {
VStack(alignment: .leading) {
List {
ForEach(viewModel.cityNameList.reversed()) { city in
NavigationLink(destination: DetailView(detail: city), label: {
Text(city.name).font(.system(size: 18))
Spacer()
Text("\(city.main.temp, specifier: "%.0f")°")
.font(.system(size: 18))
})
}
.onDelete { indexSet in
let reversed = Array(viewModel.cityNameList.reversed())
let items = Set(indexSet.map { reversed[$0].id })
viewModel.cityNameList.removeAll { items.contains($0.id) }
}
}
.refreshable {
viewModel.updatedAll()
}
TextFieldView(viewModel: viewModel)
}.navigationBarTitle("Weather", displayMode: .inline)
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
TextFieldView
struct TextFieldView: View {
#State private var cityName = ""
#State private var showingDetail = false
#FocusState var isInputActive: Bool
var viewModel: WeatherViewModel
var body: some View {
HStack {
TextField("Enter City Name", text: $cityName)
.focused($isInputActive)
Spacer()
.toolbar {
ToolbarItemGroup(placement: .keyboard) {
Button("Done") {
isInputActive = false
}
}
}
if isInputActive == false {
Button(action: {
viewModel.fetchWeather(for: cityName)
cityName = ""
self.showingDetail.toggle()
}) {
Image(systemName: "plus")
.font(.largeTitle)
.frame(width: 75, height: 75)
.foregroundColor(Color.white)
.background(Color(.systemBlue))
.clipShape(Circle())
}
.sheet(isPresented: $showingDetail) {
ForEach(0..<viewModel.cityNameList.count, id: \.self) { city in
if (city == viewModel.cityNameList.count-1) {
DetailView(detail: viewModel.cityNameList[city])
}
}
}
}
}
.frame(minWidth: 100, idealWidth: 150, maxWidth: 500, minHeight: 30, idealHeight: 40, maxHeight: 50, alignment: .leading)
.padding(.leading, 16)
.padding(.trailing, 16)
}
}
struct TextFieldView_Previews: PreviewProvider {
static var previews: some View {
TextFieldView(viewModel: WeatherViewModel())
}
}
DetailView
struct DetailView: View {
#State private var cityName = ""
#State var selection: Int? = nil
var detail: WeatherModel
var body: some View {
VStack(spacing: 20) {
Text(detail.name)
.font(.system(size: 32))
Text("\(detail.main.temp, specifier: "%.0f")°")
.font(.system(size: 44))
Text(detail.firstWeatherInfo())
.font(.system(size: 24))
}
}
}
struct DetailView_Previews: PreviewProvider {
static var previews: some View {
DetailView(detail: WeatherModel.init())
}
}
ViewModel
class WeatherViewModel: ObservableObject {
#Published var cityNameList = [WeatherModel]()
func fetchWeather(for cityName: String) {
guard let url = URL(string: "https://api.openweathermap.org/data/2.5/weather?q=\(cityName.escaped())&units=imperial&appid=<YourAPIKey>") else { return }
let task = URLSession.shared.dataTask(with: url) { data, _, error in
guard let data = data, error == nil else { return }
do {
let model = try JSONDecoder().decode(WeatherModel.self, from: data)
DispatchQueue.main.async {
self.addToList(model)
}
}
catch {
print(error)
}
}
task.resume()
}
func updatedAll() {
// keep a copy of all the cities names
let listOfNames = cityNameList.map{$0.name}
// fetch the up-to-date weather info
for city in listOfNames {
fetchWeather(for: city)
}
}
func addToList( _ city: WeatherModel) {
// if already have this city, just update
if let ndx = cityNameList.firstIndex(where: {$0.name == city.name}) {
cityNameList[ndx].main = city.main
cityNameList[ndx].weather = city.weather
} else {
// add a new city
cityNameList.append(city)
}
}
}
Model
struct WeatherModel: Identifiable, Codable {
let id = UUID()
var name: String = ""
var main: CurrentWeather = CurrentWeather()
var weather: [WeatherInfo] = []
func firstWeatherInfo() -> String {
return weather.count > 0 ? weather[0].description : ""
}
}
struct CurrentWeather: Codable {
var temp: Double = 0.0
var humidity = 0
}
struct WeatherInfo: Codable {
var description: String = ""
}
You need to use an ObservedObject in your TextFieldView to use your
original (single source of truth) #StateObject var viewModel that you create in ContentView and observe any change to it.
So use this:
struct TextFieldView: View {
#ObservedObject var viewModel: WeatherViewModel
...
}

How to observe updates in binded values SwiftUI

I'm not sure if I created my custom TextField properly, because I am unable to observe the value changes to an #Binded text. Running the following code, you may observe that print(text) is not executed when you manually enter text into the text field.
import SwiftUI
#main
struct TestOutWeirdTextFieldApp: App {
#State var text: String = "" {
didSet {
print(text)
}
}
var body: some Scene {
WindowGroup {
StandardTextField(placeholderText: "Enter text", defaultText: $text)
}
}
}
struct StandardTextField: View {
#State var placeholderText: String {
didSet {
print(#line)
print(placeholderText)
}
}
#Binding var defaultText: String {
didSet {
print(#line)
print(defaultText)
}
}
#State var systemImage: String?
#State var underlineColor: Color = .accentColor
#State var edges: Edge.Set = .all
#State var length: CGFloat? = nil
#State var secure: Bool = false
var body: some View {
HStack {
if secure {
SecureField(placeholderText, text: $defaultText)
.foregroundColor(underlineColor)
} else {
TextField(placeholderText, text: $defaultText)
.foregroundColor(underlineColor)
}
if let systemImage = systemImage {
Image(systemName: systemImage)
.foregroundColor(.white)
}
}
.overlay(
Rectangle()
.frame(height: 2)
.padding(.top, 35)
)
.foregroundColor(underlineColor)
.padding(edges, length)
}
}
struct StandardTextView_Previews: PreviewProvider {
static var previews: some View {
StandardTextField(placeholderText: "Placement text", defaultText: .constant("")).previewLayout(.sizeThatFits)
}
}
Instead of didSet you need to use .onChange(of: modifier, like
HStack {
// ... your code here
}
.onChange(of: defaultText) { print($0) } // << this !!
.overlay(

SwiftUI List single selectable item

I'm trying to create a List and allow only one item to be selected at a time. How would I do so in a ForEach loop? I can select multiple items just fine, but the end goal is to have only one checkmark in the selected item in the List. It may not even be the proper way to handle what I'm attempting.
struct ContentView: View {
var body: some View {
NavigationView {
List((1 ..< 4).indices, id: \.self) { index in
CheckmarkView(index: index)
.padding(.all, 3)
}
.listStyle(PlainListStyle())
.navigationBarTitleDisplayMode(.inline)
//.environment(\.editMode, .constant(.active))
}
}
}
struct CheckmarkView: View {
let index: Int
#State var check: Bool = false
var body: some View {
Button(action: {
check.toggle()
}) {
HStack {
Image("Image-\(index)")
.resizable()
.frame(width: 70, height: 70)
.cornerRadius(13.5)
Text("Example-\(index)")
Spacer()
if check {
Image(systemName: "checkmark")
.resizable()
.frame(width: 12, height: 12)
}
}
}
}
}
You'll need something to store all of the states instead of storing it per-checkmark view, because of the requirement to just have one thing checked at a time. I made a little example where the logic is handled in an ObservableObject and passed to the checkmark views through a custom Binding that handles checking/unchecking states:
struct CheckmarkModel {
var id = UUID()
var state = false
}
class StateManager : ObservableObject {
#Published var checkmarks = [CheckmarkModel(), CheckmarkModel(), CheckmarkModel(), CheckmarkModel()]
func singularBinding(forIndex index: Int) -> Binding<Bool> {
Binding<Bool> { () -> Bool in
self.checkmarks[index].state
} set: { (newValue) in
self.checkmarks = self.checkmarks.enumerated().map { itemIndex, item in
var itemCopy = item
if index == itemIndex {
itemCopy.state = newValue
} else {
//not the same index
if newValue {
itemCopy.state = false
}
}
return itemCopy
}
}
}
}
struct ContentView: View {
#ObservedObject var state = StateManager()
var body: some View {
NavigationView {
List(Array(state.checkmarks.enumerated()), id: \.1.id) { (index, item) in //<-- here
CheckmarkView(index: index + 1, check: state.singularBinding(forIndex: index))
.padding(.all, 3)
}
.listStyle(PlainListStyle())
.navigationBarTitleDisplayMode(.inline)
}
}
}
struct CheckmarkView: View {
let index: Int
#Binding var check: Bool //<-- Here
var body: some View {
Button(action: {
check.toggle()
}) {
HStack {
Image("Image-\(index)")
.resizable()
.frame(width: 70, height: 70)
.cornerRadius(13.5)
Text("Example-\(index)")
Spacer()
if check {
Image(systemName: "checkmark")
.resizable()
.frame(width: 12, height: 12)
}
}
}
}
}
What's happening:
There's a CheckmarkModel that has an ID for each checkbox, and the state of that box
StateManager keeps an array of those models. It also has a custom binding for each index of the array. For the getter, it just returns the state of the model at that index. For the setter, it makes a new copy of the checkbox array. Any time a checkbox is set, it unchecks all of the other boxes. I also kept your original behavior of allowing nothing to be checked
The List now gets an enumeration of the state.checkmarks -- using enumerated lets me keep your previous behavior of being able to pass an index number to the checkbox view
Inside the ForEach, the custom binding from before is created and passed to the subview
In the subview, instead of using #State, #Binding is used (this is what the custom Binding is passed to)
List {
ForEach(0 ..< RemindTimeType.allCases.count) {
index in CheckmarkView(title:getListTitle(index), index: index, markIndex: $markIndex)
.padding(.all, 3)
}.listRowBackground(Color.clear)
}
struct CheckmarkView: View {
let title: String
let index: Int
#Binding var markIndex: Int
var body: some View {
Button(action: {
markIndex = index
}) {
HStack {
Text(title)
.foregroundColor(Color.white)
.font(.custom(FontEnum.Regular.fontName, size: 14))
Spacer()
if index == markIndex {
Image(systemName: "checkmark.circle.fill")
.foregroundColor(Color(hex: 0xe6c27c))
}
}
}
}
}
We can benefit from binding collections of Swift 5.5.
import SwiftUI
struct CheckmarkModel: Identifiable, Hashable {
var id = UUID()
var state = false
}
class StateManager : ObservableObject {
#Published var checkmarks = [CheckmarkModel(), CheckmarkModel(), CheckmarkModel(), CheckmarkModel()]
}
struct SingleSelectionList<Content: View>: View {
#Binding var items: [CheckmarkModel]
#Binding var selectedItem: CheckmarkModel?
var rowContent: (CheckmarkModel) -> Content
#State var previouslySelectedItemNdx: Int?
var body: some View {
List(Array($items.enumerated()), id: \.1.id) { (ndx, $item) in
rowContent(item)
.modifier(CheckmarkModifier(checked: item.id == self.selectedItem?.id))
.contentShape(Rectangle())
.onTapGesture {
if let prevIndex = previouslySelectedItemNdx {
items[prevIndex].state = false
}
self.selectedItem = item
item.state = true
previouslySelectedItemNdx = ndx
}
}
}
}
struct CheckmarkModifier: ViewModifier {
var checked: Bool = false
func body(content: Content) -> some View {
Group {
if checked {
ZStack(alignment: .trailing) {
content
Image(systemName: "checkmark")
.resizable()
.frame(width: 20, height: 20)
.foregroundColor(.green)
.shadow(radius: 1)
}
} else {
content
}
}
}
}
struct ContentView: View {
#ObservedObject var state = StateManager()
#State private var selectedItem: CheckmarkModel?
var body: some View {
VStack {
Text("Selected Item: \(selectedItem?.id.description ?? "Select one")")
Divider()
SingleSelectionList(items: $state.checkmarks, selectedItem: $selectedItem) { item in
HStack {
Text(item.id.description + " " + item.state.description)
Spacer()
}
}
}
}
}
A bit simplified version
struct ContentView: View {
#ObservedObject var state = StateManager()
#State private var selection: CheckmarkModel.ID?
var body: some View {
List {
ForEach($state.checkmarks) { $item in
SelectionCell(item: $item, selectedItem: $selection)
.onTapGesture {
if let ndx = state.checkmarks.firstIndex(where: { $0.id == selection}) {
state.checkmarks[ndx].state = false
}
selection = item.id
item.state = true
}
}
}
.listStyle(.plain)
}
}
struct SelectionCell: View {
#Binding var item: CheckmarkModel
#Binding var selectedItem: CheckmarkModel.ID?
var body: some View {
HStack {
Text(item.id.description + " " + item.state.description)
Spacer()
if item.id == selectedItem {
Image(systemName: "checkmark")
.foregroundColor(.accentColor)
}
}
}
}
A version that uses internal List's selected mark and selection:
import SwiftUI
struct CheckmarkModel: Identifiable, Hashable {
var name: String
var state: Bool = false
var id = UUID()
}
class StateManager : ObservableObject {
#Published var checkmarks = [CheckmarkModel(name: "Name1"), CheckmarkModel(name: "Name2"), CheckmarkModel(name: "Name3"), CheckmarkModel(name: "Name4")]
}
struct ContentView: View {
#ObservedObject var state = StateManager()
#State private var selection: CheckmarkModel.ID?
#State private var selectedItems = [CheckmarkModel]()
var body: some View {
VStack {
Text("Items")
List($state.checkmarks, selection: $selection) { $item in
Text(item.name + " " + item.state.description)
}
.onChange(of: selection) { s in
for index in state.checkmarks.indices {
if state.checkmarks[index].state == true {
state.checkmarks[index].state = false
}
}
selectedItems = []
if let ndx = state.checkmarks.firstIndex(where: { $0.id == selection}) {
state.checkmarks[ndx].state = true
selectedItems = [state.checkmarks[ndx]]
print(selectedItems)
}
}
.environment(\.editMode, .constant(.active))
Divider()
List(selectedItems) {
Text($0.name + " " + $0.state.description)
}
}
Text("\(selectedItems.count) selections")
}
}

How to Transmit a View Entry Count to a Class Method

I'm having trouble with usage of a count of the number of entries in a view. I especially need to know when there are no entries in the view. I have placed debug code in the view below and the view count currants.curItem.countis updating as expected. The count status in checkForUpdates() doesn't follow the view above.
If I recall correctly I should be using #EnvironmentObject or #ObservedObject only in a view. I really need some kind of global variable that I can pass to the method checkForUpdates. It is crashing when count in checkForUpdates() is nonzero when in the view it is actually zero. It also crashes in checkForUpdates() with the error Fatal error: No ObservableObject of type Currencies found. A View.environmentObject(_:) for Currencies may be missing as an ancestor of this view.
struct manCurView: View {
#EnvironmentObject var currants: Currants
var body: some View {
List {
ForEach(currants.curItem, id: \.id) { item in
HStack {
Text(item.curCode)
.frame(width: 100, alignment: .center)
Text(item.cunName)
}
.font(.subheadline)
}
.onDelete(perform: removeItems)
}
.navigationBarTitle(Text("Manage Working Blocks"), displayMode: .inline)
HStack {
NavigationLink(destination: addCurView()) {Text("Add Working Blocks").fontWeight(.bold)}
.font(.title2)
.disabled(currants.curItem.count > 7)
Here is how the data is stored for the view above
struct CurItem: Codable, Identifiable {
var id = UUID()
var cunName: String
var curName: String
var curCode: String
var curSymbol: String
var curRate: Double
}
class Currants: ObservableObject {
#Published var curItem: [CurItem]
}
And here is the class and method where I would like to use count from the view manCurView
class BlockStatus: ObservableObject {
#EnvironmentObject var globalCur : Currants
#ObservedObject var netStatus : TestNetStatus = TestNetStatus()
func checkForUpdates() -> (Bool) {
if netStatus.connected == true {
if globalCur.curItem.count > 0 {
Without a minimal reproducible example it is very difficult to give you exact code but you can try something like the code below in your manCurView
#StateObject var blockStatus: BlockStatus = BlockStatus()
.onChange(of: currants.curItem.count, perform: { value in
print("send value from here")
blockStatus.arrayCount = value
})
And adding the code below to BlockStatus
#Published var arrayCount: Int = 0{
didSet{
//Call your method here
}
}
Look at the code below.
import SwiftUI
import Combine
struct CurItem: Codable, Identifiable {
var id = UUID()
}
class Currants: ObservableObject {
#Published var curItem: [CurItem] = [CurItem(), CurItem(), CurItem(), CurItem()]
}
class TestNetStatus: ObservableObject {
static let sharedInstance = TestNetStatus()
#Published var connected: Bool = false
init() {
//Simulate changes in connection
Timer.scheduledTimer(withTimeInterval: 10, repeats: true){ timer in
self.connected.toggle()
}
}
}
class BlockStatus: ObservableObject {
#Published var arrayCount: Int = 0{
didSet{
checkForUpdates()
}
}
#Published var checkedForUpdates: Bool = false
var netStatus : TestNetStatus = TestNetStatus.sharedInstance
//private var cancellable: AnyCancellable?
init() {
//Maybe? if you want to check upon init.
//checkForUpdates()
//Something like the code below is also possible but with 2 observed objects the other variable could be outdated
// cancellable = netStatus.objectWillChange.sink { [weak self] in
// self?.checkForUpdates()
// }
}
func checkForUpdates() {
if netStatus.connected == true {
if arrayCount > 0 {
checkedForUpdates = true
}else{
checkedForUpdates = false
}
}else{
checkedForUpdates = false
}
}
}
struct ManCurView: View {
#StateObject var currants: Currants = Currants()
#StateObject var blockStatus: BlockStatus = BlockStatus()
#StateObject var testNetStatus: TestNetStatus = TestNetStatus.sharedInstance
var body: some View {
List {
Text("checkedForUpdates = " + blockStatus.checkedForUpdates.description).foregroundColor(blockStatus.checkedForUpdates ? Color.green : Color.red)
Text("connected = " + blockStatus.netStatus.connected.description).foregroundColor(blockStatus.netStatus.connected ? Color.green : Color.red)
ForEach(currants.curItem, id: \.id) { item in
HStack {
Text(item.id.uuidString)
.frame(width: 100, alignment: .center)
Text(item.id.uuidString)
}
.font(.subheadline)
}
//Replaced with toolbar button for sample
//.onDelete(perform: removeItems)
//When the array count changes
.onChange(of: currants.curItem.count, perform: { value in
blockStatus.arrayCount = value
})
//Check when the networkStatus changes
.onChange(of: testNetStatus.connected, perform: { value in
//Check arrayCount
if blockStatus.arrayCount != currants.curItem.count{
blockStatus.arrayCount = currants.curItem.count
}else{
blockStatus.checkForUpdates()
}
})
}
.navigationBarTitle(Text("Manage Working Blocks"), displayMode: .inline)
//Replaced addCurView call with toolbar button for sample
.toolbar(content: {
ToolbarItem(placement: .navigationBarTrailing, content: {
Button("add-currant", action: {
currants.curItem.append(CurItem())
})
})
ToolbarItem(placement: .navigationBarLeading, content: {
Button("delete-currant", action: {
if currants.curItem.count > 0{
currants.curItem.removeFirst()
}
})
})
})
}
}
Here is ContentView: Notice in the menu that because this is a view I can use count directly to disable entry input. Down in getData() notice that I'm calling blockStatus.checkForUpdates() to determine if is OK to call the API. A fault will occur if currants.curItem.count = 0
I just realized that technically getData() is part of the ContentView so I can change the call below to if blockStatus.checkForUpdates() == true && currants.curItem.count != 0 {
I'm going to spend some time studying your suggestions above to see if I could use this in the future.
So thanks for all the help by looking into this. I wasn't aware of the suggestions on code displayed on Stackoverflow. I'll be sure to follow those guidelines in the future. Galen
import SwiftUI
import CoreData
import Combine
struct ContentView: View {
#EnvironmentObject var userData: UserData
#EnvironmentObject var currants: Currants
#EnvironmentObject var blockStatus: BlockStatus
var body: some View {
NavigationView {
VStack (alignment: .center) {
Text("Title")
.font(.title)
.fontWeight(.bold)
Spacer()
Group {
NavigationLink(destination: entryView()) {Text("Entry")}
.disabled(currants.curItem.count == 0)
Spacer()
NavigationLink(destination: totalView()) {Text("View Totals")}
Spacer()
NavigationLink(destination: listView()) {Text("View Entries")}
Spacer()
NavigationLink(destination: xchView()) {Text("View Dates")}
}
Rectangle()
.frame(height: 130)
.foregroundColor(Color.white)
}
.font(.title2)
.navigationBarItems(leading: NavigationLink (destination: settingsView()) {
Image(systemName: "gear")
.foregroundColor(.gray)
.font(.system(.title3))
}, trailing: NavigationLink( destination: aboutView()) {
Text("About")
})
.onAppear(perform: getData)
}
}
func getData() {
// check criteria for updating data once daily
if blockStatus.checkForUpdates() == true {
print(" doing update")
---- API HERE -----
}.resume()
}
}
}

SwiftUI Reload View

I have a struct which shuffles and Lists records from CoreData.
I would like to reload / Refresh the List view with a Button.
I tried to use a function from within the Button.
Is there a way I can do this?
var body: some View {
VStack {
List {
ForEach(dictionary.shuffled().prefix(upTo: 10),id: \.self) { word in
HStack {
Text("\(word.englishWord)")
.foregroundColor(Color.blue)
Text("| \(word.urhoboWord) |")
.foregroundColor(Color.green)
Image(word.imageName)
.resizable()
.frame(width:40, height: 40)
}//HStack
}//End of ForEach
}//End of List
//Button to reload and shuffle list
Button(action: {}) {
Text("Shuffle")
.padding()
.background(Color.black)
.foregroundColor(Color.white)
.cornerRadius(6)
}
.navigationBarTitle(Text("Begin Learning"),displayMode: .inline)
Just trigger any value of the #State or #Published of #ObservableObject.
If you do not have such, just create one:
#State var refresh: Bool = false
func update() {
refresh.toggle()
}
You should move this dictionary.shuffled().prefix(upTo: 10) to your ViewModel and your view just reload base on the data.
Take a look at this code for reference:
struct SampleShuffleView : View {
#ObservedObject var viewModel : ShuffleViewModel = ShuffleViewModel()
var body : some View {
VStack {
List(self.viewModel.listData, id: \.self) { str in
Text(str)
}
Button(action: self.shuffle) {
Text("Shuffle me").padding()
}.background(Color.white).padding()
}
}
func shuffle() {
self.viewModel.shuffle()
}
}
class ShuffleViewModel : ObservableObject {
#Published var listData = ["one", "two", "three", "four"]
func shuffle() {
listData.shuffle()
//or listData = dictionary.shuffled().prefix(upTo: 10)
}
}
Note: All view's components will be reloaded when #ObservedObject changes, so consider to separate smaller view-viewmodel(s), or using #State variable.
Hope this helps.
Think about. To show array and shuffle on tap, do exactly what you would like to see. first show us the array in some "list" like manner and next shuffle it on user action.
struct ContentView: View {
#State var arr = ["ALFA", "BETA", "GAMA", "DELTA"]
var body: some View {
VStack {
VStack {
Divider()
ForEach(arr, id: \.self) { element in
VStack {
Text(element)
Divider()
}
}
}
Spacer()
Button(action: {
self.arr.shuffle()
}) {
Text("Shuffle")
}
Spacer()
}
}
}
arr.shuffle() changed the #State of View and force SwiftUI to "reload it" automatically.