• Jul 26, 2023 doesn't have a target for net7.0-ios ios-arm64

  If you get this error:

  /usr/local/share/dotnet/sdk/7.0.306/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(5,5): 
  Error NETSDK1047: Assets file ‘/…/obj/project.assets.json' doesn't have a target for 'net7.0-ios/ios-arm64'. 
  Ensure that restore has run and that you have included 'net7.0-ios' in the TargetFrameworks 
  for your project. 
  You may also need to include 'ios-arm64' in your project's RuntimeIdentifiers. (NETSDK1047) (…)
  

  In Visual Studio open the command prompt and enter

  dotnet restore -r ios-arm64
  

  From https://github.com/xamarin/xamarin-macios/issues/14753#issuecomment-1105360239

• Jun 12, 2023 If your C++ files are not compiling when adding them to Xcode

  Check that when you import the containing folder you select Create groups rather than Create folder references in the import dialog

• Jun 12, 2023 Using C++ from Swift in Xcode 15 beta One

  Make sure you don’t have objective-c and objective-c++ selected under Build-Settings Apple-Clang Module Verifier - Options for the C++ framework - just objective-c++

  Also ensure your C++ “.hpp” file is set to publc in the target membership for the file properties if you can’t #import with an error file not found

• Jun 5, 2023 When I archive a project in Xcode it shows the wrong version. Why might that be?

  Answer here

  For a watch-only app, select the iOS target and update the value in Build Settings -> Versioning -> Marketing Version.

• Apr 9, 2023 Using a Toggle in a MenuBar app

  Also launching an app on system startup

  import SwiftUI
  import ServiceManagement
  import Combine
  
  @main
  struct WatchControl_MacApp: App {
      @ObservedObject var menuState = LaunchOnStartupState.shared
  
      var body: some Scene {
          MenuBarExtra("WatchControl", image: "Image") {
              Toggle(isOn: $menuState.launchOnLogin) {
                  Text("Launch on startup")
              }
              .toggleStyle(.checkbox)
              Divider()
              Button("Quit") {
                  NSApplication.shared.terminate(nil)
              }.keyboardShortcut("q")
          }
      }
  }
  
  
  class LaunchOnStartupState : ObservableObject {
      static var shared = LaunchOnStartupState()
      @Published var launchOnLogin = SMAppService.mainApp.status == .enabled
      var cancelable: AnyCancellable?
      
      private init() {
          cancelable = $launchOnLogin.sink { newValue in
              do {
                  if newValue {
                      print(“Calling SMAppService.mainApp.register()")
                      try SMAppService.mainApp.register()
                  } else {
                      print(“Calling SMAppService.mainApp.unregister()")
                      try SMAppService.mainApp.unregister()
                  }
              } catch {
                  print(“Error \(newValue ? "" : "un")registering for startup: \(error)")
              }
          }
      }
  }
  
  

• Apr 9, 2023 Encrypting and decrypting using a symetric key

  Largely generated from ChatGPT

  import Foundation
  import CommonCrypto
  
  class CryptUtils {
      static func encrypt(data: Data, key: String) -> Data? {
          let keyLength = kCCKeySizeAES128
          let keyData = paddedKeyData(for: key, keyLength: keyLength)
  
          let bufferSize = data.count + kCCBlockSizeAES128
          var buffer = Data(count: bufferSize)
  
          var numBytesEncrypted: Int = 0
          let cryptStatus = keyData.withUnsafeBytes { keyBytes -> CCCryptorStatus in
              data.withUnsafeBytes { dataBytes -> CCCryptorStatus in
                  buffer.withUnsafeMutableBytes { bufferBytes -> CCCryptorStatus in
                      return CCCrypt(
                          CCOperation(kCCEncrypt),
                          CCAlgorithm(kCCAlgorithmAES),
                          CCOptions(kCCOptionPKCS7Padding),
                          keyBytes.baseAddress,
                          keyLength,
                          nil, // Use ECB mode (no Initialization Vector)
                          dataBytes.baseAddress,
                          data.count,
                          bufferBytes.baseAddress,
                          bufferSize,
                          &numBytesEncrypted
                      )
                  }
              }
          }
  
          if cryptStatus == kCCSuccess {
              buffer.count = numBytesEncrypted
              return buffer
          } else {
              print("Error: Failed to encrypt data")
              return nil
          }
      }
      
      static func decrypt(data: Data, key: String) -> Data? {
          let keyLength = kCCKeySizeAES128
          let keyData = paddedKeyData(for: key, keyLength: keyLength)
  
          let bufferSize = data.count + kCCBlockSizeAES128
          var buffer = Data(count: bufferSize)
  
          var numBytesDecrypted: Int = 0
          let cryptStatus = keyData.withUnsafeBytes { keyBytes -> CCCryptorStatus in
              data.withUnsafeBytes { dataBytes -> CCCryptorStatus in
                  buffer.withUnsafeMutableBytes { bufferBytes -> CCCryptorStatus in
                      return CCCrypt(
                          CCOperation(kCCDecrypt),
                          CCAlgorithm(kCCAlgorithmAES),
                          CCOptions(kCCOptionPKCS7Padding),
                          keyBytes.baseAddress,
                          keyLength,
                          nil, // Use ECB mode (no Initialization Vector)
                          dataBytes.baseAddress,
                          data.count,
                          bufferBytes.baseAddress,
                          bufferSize,
                          &numBytesDecrypted
                      )
                  }
              }
          }
  
          if cryptStatus == kCCSuccess {
              buffer.count = numBytesDecrypted
              return buffer
          } else {
              print("Error: Failed to decrypt data")
              return nil
          }
      }
  
      private static func paddedKeyData(for key: String, keyLength: Int) -> Data {
          let keyData = key.data(using: .utf8)!
          let paddedKeyData = NSMutableData(length: keyLength)!
          
          keyData.withUnsafeBytes { (keyBytes: UnsafeRawBufferPointer) in
              if let baseAddress = keyBytes.baseAddress {
                  paddedKeyData.replaceBytes(in: NSRange(location: 0, length: min(keyData.count, keyLength)), withBytes: baseAddress)
              }
          }
          
          return paddedKeyData as Data
      }
  
  }
  

• Apr 9, 2023 Displaying a SwiftUI view from a MenuBar only app

  import AppKit
  import SwiftUI
  
  struct MyAlertView: View {
      var body: some View {
          VStack {
              Text("This is a SwiftUI view in an alert.")
              Button("OK") {
                  // Handle button action
              }
          }
          .frame(width: 300, height: 200)
      }
  }
  
  func activateApp() {
      let myApp = NSRunningApplication.current
      myApp.activate(options: .activateIgnoringOtherApps)
  }
  
  func showAlertWithSwiftUIView() {
      let panel = NSPanel(contentRect: NSRect(x: 0, y: 0, width: 300, height: 200),
                          styleMask: [.titled, .closable, .fullSizeContentView],
                          backing: .buffered,
                          defer: false)
      panel.title = "Alert"
      panel.center()
  
      activateApp()
      panel.makeKeyAndOrderFront(nil)
  
      let hostingView = NSHostingView(rootView: MyAlertView(isPresented: .init(get: {
          panel.isVisible
      }, set: { isVisible in
          if !isVisible {
              panel.orderOut(nil)
          }
      })))
      panel.contentView = hostingView
  }
  
  

• Feb 26, 2022 Including changes in memory when querying core data

  let context = PersistenceController.shared.container.viewContext
  return try context.performAndWait {
      let fetchRequest = DbResource.fetchRequest()
      fetchRequest.includesPendingChanges = true
      fetchRequest.predicate = NSPredicate(format: "bodyHash == %@", bodyHash)
      return try context.fetch(fetchRequest).first
  }
  

• Feb 22, 2022 Extending an optional Double to convert it to an NSNumber

  extension Optional where Wrapped == Double {
      var asNSNumber : NSNumber? {
          if let val = self {
              return NSNumber(floatLiteral: val)
          } else {
              return nil
          }
      }
  }
  

• Sep 29, 2021 Custom Error with localizedDescription

  enum EncyptError: LocalizedError {
      case error(String)
      
      public var errorDescription: String? {
          switch self {
          
          case .error(let message):
              return message
          }
      }
  }
  

• Sep 4, 2021 Converting an audio (PCM) CMSampleBuffer to a Data instance

  Assumes you set up your AVCaptureAudioDataOutput something like this (the key assumption is the bit depth):

  let audioOutput = AVCaptureAudioDataOutput()
  audioOutput.audioSettings =  [
      AVFormatIDKey: kAudioFormatLinearPCM,
      AVNumberOfChannelsKey: 1,
      AVSampleRateKey: 16000.0,
  
      AVLinearPCMBitDepthKey: 16,
      AVLinearPCMIsBigEndianKey: false,
      AVLinearPCMIsFloatKey: false,
      AVLinearPCMIsNonInterleaved: false
  ]
  

  This is the setSampleBufferDelegate delegate:

  func captureOutput(_ output: AVCaptureOutput, didOutput sampleBuffer: CMSampleBuffer, from connection: AVCaptureConnection) {
      let byteCount = sampleBuffer.numSamples * sampleBuffer.sampleSize(at: 0)
  
      do {
          let unsafeRawPointer = UnsafeMutableRawPointer.allocate(byteCount: byteCount, alignment: 0)
          let pcmBufferPointer = UnsafeMutablePointer<AudioBufferList>.allocate(capacity: 1)
          pcmBufferPointer.initialize(to: AudioBufferList(mNumberBuffers: 1, mBuffers: AudioBuffer(mNumberChannels: 1, mDataByteSize: UInt32(byteCount), mData: unsafeRawPointer)))
  
          try sampleBuffer.copyPCMData(fromRange: 0..<sampleBuffer.numSamples, into: pcmBufferPointer)
  
          let data = Data(bytes: unsafeRawPointer, count: byteCount)
          // Do something with the data
  
      } catch {
          logE("Error converting buffer: \(error.localizedDescription)")
      }
  
  

  You will likely not want to allocate the buffer on each callback.

• Aug 29, 2021 Overriding default Help menu in SwiftUI Mac App

  import SwiftUI
  
  @main
  struct AppleWatchAlexaApp: App {
      var body: some Scene {
          WindowGroup {
              ContentView()
                  .resizedonMacOS(widthPercent: 1)
          }
          .commands {
              CommandGroup(replacing: .help) {
                  NavigationLink("Voice in a Can Help", destination:
                                  WebView(url: URL(string: "https://voiceinacan.com/ios-faq/")!)
                  )
              }
          }
      }
  }
  
  

• Aug 23, 2021 Date as yyyymmddhhss

  extension Date {
      var yyymmddhhss: String {
          let dateFormatter = DateFormatter()
          dateFormatter.dateFormat = "yyyMMddhhmmss"
          return dateFormatter.string(from: self)
      }
  }
  

• Aug 22, 2021 'Unable to present. Please file a bug.' with multiple NavigationLinks

  This is a known issue but the workaround of adding an empty NavigationLink didn’t work for me.

  On my Mac app when I have multiple NavigationLinks I get Unable to present. Please file a bug. when I tap on more than one.

  My hacky solution is to create a NavigationButton that replaces the NavigationLink

  struct NavigationButton<Destination>: View where Destination: View {
      let text: String
      let destination: Destination
      @State var showing = false
      
      init(_ text: String, destination: Destination) {
          self.text = text
          self.destination = destination
      }
      
      var body: some View {
          ZStack {
              if showing {
                  NavigationLink(text, destination: destination, isActive: $showing)
                      .opacity(0)
              }
              Button(text) {
                  showing = true
              }
          }
      }
  }
  

• Aug 18, 2021 Decoding a JWT in Swift

  Surprised it isn’t built-in. I’ve used JWTDecode.swift to decode tokens:

  guard let jwt = try? decode(jwt: token),
        let expires = jwt.expiresAt else {
      print("Can't decode jwt")
      return
  }
  

• Aug 18, 2021 if or guard on enum with a parameter instead of using a switch

  Using an if or a guard instead of a switch

  guard case let .onLogin(account) = gigyaEvent,
        let uid = account.UID else {
      return
  }
  

• Aug 18, 2021 Enabling Core Data Encryption in Swift

  From https://stackoverflow.com/a/65525585/3390

  container = NSPersistentContainer(name: "Model")
  container.persistentStoreDescriptions.first!.setOption(FileProtectionType.complete as NSObject,
                                                         forKey: NSPersistentStoreFileProtectionKey)
  container.loadPersistentStores(completionHandler: { (storeDescription, error) in
  

• Aug 18, 2021 Sharing files

  Use share func from https://stackoverflow.com/a/59515229/3390

• Aug 18, 2021 Creating ZIP files in Swift

  I’ve used ZIPFoundation

  let archive = Archive(accessMode: .create) // Create it in memory
  
  // Add a file
  try archive?.addEntry(with: "export/photos/\(photo_id)", fileURL: filename)
  
  
  // Add string as a file
  try archive?.addEntry(with: "export/data.csv", type: .file, uncompressedSize: UInt32(output.count)) { position, size in
                  return output.data(using: .utf8)!
              }
  
  // Write ZIP as a file
  if let data = archive?.data {
      let exportFile = FileManager.default.temporaryDirectory.appendingPathComponent("export.zip")
      print("Path: \(exportFile.path)")
      try data.write(to: exportFile)
  }
  

• Aug 5, 2021 Add hours from one date to another date

  let date = Calendar.current.date(byAdding: DateComponents(hour: Calendar.current.component(.hour, from: otherDate)), to: thisDate)
  

• Jun 26, 2021 Delete all local git branches except main

  git for-each-ref --format '%(refname:short)' refs/heads | grep -v main | xargs git branch -D
  

• May 29, 2021 Recording a simulator video

  xcrun simctl io booted recordVideo --force --codec h264 fred.mov
  

• May 9, 2021 Stop iPad Split View in SwiftUI

  Set navigationViewStyle to StackNavigationViewStyle

  NavigationView {
      TheTabView()
  }
  .navigationViewStyle(StackNavigationViewStyle())
  

• May 5, 2021 Launching processes in Swift

  Launching multiple commands in Swift

          do {
              try writePost()
              let add = Process()
              add.currentDirectoryPath = root
              add.executableURL = URL(fileURLWithPath: git)
              add.arguments = ["add", "."]
              try add.run()
              
              let commit = Process()
              commit.currentDirectoryPath = root
              commit.executableURL = URL(fileURLWithPath: git)
              commit.arguments = ["commit","-m", "\"title\""]
              try commit.run()
              commit.waitUntilExit()
              
              let push = Process()
              push.currentDirectoryPath = root
              push.executableURL = URL(fileURLWithPath: git)
              push.arguments = ["push"]
              try push.run()
              push.waitUntilExit()
              
          } catch {
              errorMessage =  "Error: \(error)"
          }
  

• Mar 18, 2021 XCTest can't tap SwiftUI Toggle

  Using tap on a SwiftUI Toggle wasn’t working for me:

      let app = XCUIApplication()
      let sw = app.switches["My SwiftUI Toggle"]
      XCTAssert(sw.value as! String == "0")
      sw.tap()
      XCTAssert(sw.value as! String == "1")
  

  The above fails. I think this is because tapping the label part of the Toggle does nothing. Instead, I try to tap the switch part of it, which works:

      let app = XCUIApplication()
      let sw = app.switches["My SwiftUI Toggle"]
      XCTAssert(sw.value as! String == "0")
      sw.coordinate(withNormalizedOffset: CGVector.zero).withOffset(CGVector(dx: sw.frame.width - 10, dy: sw.frame.height / 2)).tap()
      XCTAssert(sw.value as! String == "1")
  

  Now it works - I tap in the vertical center, on the right side of the switch, minus ten points.

• Feb 13, 2021 Formatting a single swift date field in JSON

  You want to use one encoding strategy overall to encode JSON dates, but one particular field needs to be formatted using a different formatting?

  Normally you’d set the encoding strategy for the whole encoding:

      let encoder = JSONEncoder()
      encoder.dateEncodingStrategy = .millisecondsSince1970 // or iso8601
      encoder.encode(myObject)
  

  But what if deep down in the structure or class, one date field needs to be formatted a different way, such as the timeStamp field here?

      struct GeolocationState: EventBase {
          let timestamp: Date
          let coordinate: Coordinate
          let altitude: Altitude?
          let heading: Heading?
          let speed: Speed?
      }
  

  My solution is to wrap the date in my own struct, and then I can control the encoding for that:

      struct GeolocationState: EventBase {
          let timestamp: ISO8601Date
          let coordinate: Coordinate
          let altitude: Altitude?
          let heading: Heading?
          let speed: Speed?
      }
  
      struct ISO8601Date: Encodable {
          static let formatter = ISO8601DateFormatter()
          let date: Date
          init(_ date: Date) { self.date = date }        
  
          enum CodingKeys: CodingKey { case date }
          
          func encode(to encoder: Encoder ) throws {
              var container = encoder.singleValueContainer()
              try container.encode(ISO8601FormattedDate.formatter.string(from: date))
          }
      }
  

• Jan 19, 2021 Detecting when state variable changes

  I tried using willSet or didSet on an @State variable, but it didn’t work

  @State var consumed: Bool = false {
      didSet {
          print("never called")
      }
  }
  

  Instead what works is to use the onChange event:

  Toggle("My toggle", isOn: $consumed)
      .onChange(of: self.consumed) { v in
          print("is called")
      }
  
  

• Jan 13, 2021 isActive not working to go back when three levels deep

  In my app I am using NavigationLink.isActive to programatically go back by setting a bound variable to false. I was doing this several levels deep, and although I could initially go back, once I pushed several views onto the stack, and then went back, I found the back button stopped working on one of the pages.

  I also noticed this error:

  2021-01-13 18:02:26.660739+0100 Resolute[6210:333764] [Assert] displayModeButtonItem is internally managed and not exposed for DoubleColumn style. Returning an empty, disconnected UIBarButtonItem to fulfill the non-null contract.
  

  This Stack Overflow page suggested setting the navigationViewStyle to StackNavigationViewStyle:

  NavigationView {
      ...
  }
  .navigationViewStyle(StackNavigationViewStyle())
  

  This both got rid of the error, and the back button started working (setting the isActive bound variable to false)

• Jan 10, 2021 VS Code Regex to duplicate the text on each line

  Replace (.*) with $1 $1

• Jan 6, 2021 Adding days/weeks/months to dates

  let today = Date()
  let date = Calendar.current.date(byAdding: .day, value: 7, to: today)!
  

• Jan 1, 2021 Converting an object to a raw pointer and back

  To a pointer

  let rawPointer = unsafeBitCast(anObject, to: UnsafeMutableRawPointer.self)
  

  … and back

  let anObject = Unmanaged<TheClassObjectsClass>.fromOpaque(UnsafeRawPointer(rawPointer)).takeUnretainedValue()
  

• Dec 29, 2020 A failed attempt to get an AVAsset from a data uri

  This is my attempt. It doesn’t work. The best workaround is to write the data to file first

  var base64 = data.base64EncodedString(options: [])
  
  base64 = base64.replacingOccurrences(of: "=", with: "")
  base64 = base64.replacingOccurrences(of: "+", with: "-")
  base64 = base64.replacingOccurrences(of: "/", with: "_")
  
  let dataURL = URL(string: "data:audio/mpeg;base64,\(base64)")!
  let asset = AVAsset(url: dataURL)
  let millis =  Int(CMTimeGetSeconds(asset.duration)*1000) // Returns zero
  

• Dec 27, 2020 When JSON encoding a Double there are too many decimal places

  If you are trying to generate JSON and a double is encoded with loads of decimal places and weird “1” at the end, like this:

  struct Coordinate: Encodable {
      let latitudeInDegrees: Double
      let longitudeInDegrees: Double
      let accuracyInMeters: Double
  }
  let coordinate = Coordinate(latitudeInDegrees: 37.785834, longitudeInDegrees: -122.406417, accuracyInMeters: 5)
  

  Generates JSON:

  {
      "coordinate" : {
          "accuracyInMeters" : 5,
          "latitudeInDegrees" : 37.785834000000001,
          "longitudeInDegrees" : -122.406417
      }
  }
  

  Change the type from Double to Decimal:

  struct Coordinate: Encodable {
      let latitudeInDegrees: Decimal
      let longitudeInDegrees: Decimal
      let accuracyInMeters: Decimal
  }
  

• Dec 26, 2020 Making JSON have both sorted keys and pretty printed

  let encoder = JSONEncoder()
  encoder.outputFormatting = JSONEncoder.OutputFormatting([.prettyPrinted, .sortedKeys])
  

• Dec 20, 2020 Adding a framework to a test target

  I wanted to add the AnyCodable to both my iOS project, and the test project that tests it.

  When I added it to just my iOS project I got the error Undefined symbol: nominal type descriptor for AnyCodable.AnyCodable when trying to run tests.

  My solution was to remove the framework, and then re-add it, this time specifying the test target as the target into which the framework should be added.

  Once I did that, I was then able to go to my iOS project’s target, and in the General pane, scroll down to Frameworks, Libraries, and Embedded Content and add it there.

• Dec 20, 2020 Swift does not preserve field order when encoding json

  Converting code from .NET to Swift I’ve discovered that Swift does not preserve the order in which fields are declared when encoding JSON.

  There is a bug about it: https://bugs.swift.org/browse/SR-7992

  Support forums are full of people saying the order should not matter, but the reality is that some servers, over which we have no control, require a specific ordering, and it would be nice if Swift supported specifying or even preserving the field order when encoding JSON.

  My solution, in a very limited situation, was to use string interpolation to insert my values into a pre-encoded JSON string which had the correct ordering.

• Dec 15, 2020 Indexing into a string

  // [3] = (key = "Content-Type", value = "multipart/related; boundary=------abcde123; type=application/json")
  let boundaryKey = "boundary="
  guard let contentType = headers["Content-Type"] else {
      logE("opened", "No content type header)")
      return 
  }
  
  let contentTypeParts = contentType.split(separator: ";").map {$0.trimmingCharacters(in: .whitespaces) }
  guard let boundaryPart = contentTypeParts.first(where: {  $0.starts(with: boundaryKey)}) else {
      logE("opened", "Can't find boundary in \(contentType)")
      return
  }
  
  let boundary = String(boundaryPart[boundaryPart.index(boundaryPart.startIndex, offsetBy: boundaryKey.count)...])
  
  

• Dec 6, 2020 Adding a font to a SwiftUI app

  Download and unzip the font, for example from https://fonts.google.com/specimen/Poppins

  Drag the .ttf (for example Poppins-Bold.ttf) file into your Xcode project, perhaps in a folder called Fonts and ensure that it is included in your project’s target (select it and verify Target Membership in the file properties).

  Edit your info.plist and add a top level Fonts provided by application node, and then a child Item 0 node with a value of the name of your font, for example Poppins-Bold.ttf.

  Use the font in your app:

  Text("hello")
      .font(.custom("Poppins-Bold", size: 48))
  

• Dec 6, 2020 SwiftUI Radial Gradient with hex

  background: linear-gradient(197.54deg, #D0A0C3 0%, #D94E42 52.73%, #FAEF64 100%);
  

  struct Hello: View {
      var body: some View {
          VStack() {
              Text("hello")
          }
          .frame(maxWidth: .infinity, maxHeight: .infinity)
          .foregroundColor(.white)
          .background(LinearGradient(gradient: Gradient(colors: [
              Color(red: 0xD0/255.0, green: 0xA0/255.0, blue: 0xC3/255.0),
              Color(red: 0xD9/255.0, green: 0x4E/255.0, blue: 0x42/255.0),
              Color(red: 0xFA/255.0, green: 0xEF/255.0, blue: 0x64/255.0),
          ]),
          startPoint: .topTrailing, endPoint: .bottomLeading))
      }
  }
  

  

• Dec 4, 2020 Opening a URL

  Button("How?") {
      UIApplication.shared.open(URL(string: "https://support.garmin.com/en-US/?faq=lK5FPB9iPF5PXFkIpFlFPA")!)
  }
  

• Dec 4, 2020 Multiple Sheets not working in SwiftUI

  You don’t use multiple sheets … instead use a single sheet with an enum. https://stackoverflow.com/a/63181811/3390

      @State var activeSheet: ActiveSheet? = .showGarminExplanation
      
      enum ActiveSheet: Identifiable {
          case fitbitLogin, showGarminExplanation, showXaiomiExplanation, showOuraExplanation
          
          var id: Int {
              hashValue
          }
      }
  
  ...
          .sheet(item: $activeSheet)  { item in
              switch item {
              case .fitbitLogin:
                  SafariView(url: fitbit.url!)
              case .showGarminExplanation:
                  GarminExplanationView()
              case .showXaiomiExplanation:
                  GarminExplanationView()
              case .showOuraExplanation:
                  GarminExplanationView()
              }
          }
  
  

• Nov 27, 2020 RadioGroupPickerStyle not found

  The reason you can’t find RadioGroupPickerStyle on in your SwiftUI iOS app is that it is only available on macOS

• Nov 27, 2020 SwiftUI navigating

  var body: some View {
      NavigationView {
          VStack {
              Spacer()
              Image("someimage")
                  .resizable()
                  .aspectRatio(contentMode: .fit)
              Spacer()
          }
          .navigationBarTitle("Welcome!")
          .navigationBarItems(trailing:
                                  NavigationLink("Next", destination: AnotherView(), isActive: $moveNext)
          )
          .onAppear(perform: {
              DispatchQueue.main.asyncAfter(deadline: .now() + 2) {
                  withAnimation {
                      self.moveNext = true
                  }
              }
          })
  
      }
      
  }
  

• Nov 25, 2020 Swift Localization
  1. Open Project properties and under Localizations add French to Base and English-Development Language
  2. Add a new file called Localizable.strings using the New File dialog and filtering to Strings File
  3. Right-click the new file, select Show File Inspector and under Localization check both English and French
  4. Two sub-files under Localizable.strings should have appeared

  To preview a language in SwiftUI

  struct HomeView_Previews: PreviewProvider {
      static var previews: some View {
          HomeView()
              .environment(\.locale, .init(identifier: "fr"))
      }
  }
  

• Nov 25, 2020 Rounding the rectangle of a view background

  VStack {
      Label("text", systemImage: "pills.fill")
          .foregroundColor(.orange)
          .font(.title3)
  }
  .background(RoundedRectangle(cornerRadius: 25.0).foregroundColor(.orange).opacity(0.05))
  

• Nov 25, 2020 Averaging a collection of values in Swift

  let averageMinutesAsleep = itemsToConsider.reduce(0) { $0 + $1.minutesAsleep} / itemsToConsider.count
  

• Nov 24, 2020 Interval in seconds between two dates in Swift

  let seconds = Int(Date().timeIntervalSince(expires))
  

• Nov 24, 2020 Swift date in user defaults

  let expires = defaults.object(forKey: defaultsTokenExpiresName) as? Date
  

• Nov 24, 2020 Switching between open tabs in Xcode

  Next Tab: Command-{ which is Command-Shift-[ Prevous Tab: Command-{ which is Command-Shift-]

• Nov 24, 2020 Using the keychain from Swift

  Based on a blog post I wrote on Sharing tokens between iOS, macOS and watchOS app using the iCloud KeyChain which is I am sure based on something else.

  import os
  import Foundation
  
  class KeyStore {
      func store(name: String, token : String) {
          let data = token.data(using: .utf8)!
          let addquery: [String: Any] = [kSecClass as String: kSecClassGenericPassword as String,
                                         kSecAttrAccount as String: name,
                                         kSecValueData as String: data
          ]
          SecItemDelete(addquery as CFDictionary)
          let status : OSStatus = SecItemAdd(addquery as CFDictionary, nil)
          guard status == errSecSuccess else {
              os_log("store: whoops")
              return
          }
      }
      
      func clear(name: String) {
          let addquery: [String: Any] = [kSecClass as String: kSecClassGenericPassword as String,
                                         kSecAttrAccount as String: name
          ]
          SecItemDelete(addquery as CFDictionary)
      }
      
      func retrieve(name: String) -> String? {
          let getquery: [String: Any] = [kSecClass as String: kSecClassGenericPassword,
                                         kSecAttrAccount as String: name,
                                         kSecReturnData as String: kCFBooleanTrue!,
                                         kSecMatchLimit as String : kSecMatchLimitOne
          ]
          
          var item: CFTypeRef?
          let status = SecItemCopyMatching(getquery as CFDictionary, &item)
          guard status == errSecSuccess else {
              os_log("keyStore.retrieve SecItemCopyMatching error \(status)")
              return nil
          }
          
          guard let data = item as? Data? else {
              os_log("keyStore.retrieve not data")
              return nil
          }
          
          return String(data: data!, encoding: String.Encoding.utf8)
      }
      
  }
  

• Nov 23, 2020 Bolding text in SwiftUI

  Text("normal text ") + Text("bold text").bold() + Text(" normal text") 
  

• Nov 22, 2020 A VS Code Snippet to create Jekyll blog post frontmatter

  "entry": {
      "scope": "markdown",
      "prefix": "en",
      "body": [
          "---",
  "layout: post",
  "title:  \"${1:title}\"",
  "date:   $CURRENT_YEAR-$CURRENT_MONTH-$CURRENT_DATE $CURRENT_HOUR:$CURRENT_MINUTE:$CURRENT_SECOND +0100",
  "---",
  "${2:body}"
      ],
      "description": "post"
  }
  

  Create/update a root-level settings.json to enable tab-completion:

  {
      "editor.tabCompletion": "on"
  }
  

• Nov 21, 2020 Stopping SwiftUI Text from being clipped

  Text("You've been getting an average of 7 hours and 23 minutes of sleep each night over the last month, which is great.  Keep it up!")
      .fixedSize(horizontal: false, vertical: true)
      .padding()
  

  From Reddit

• Nov 21, 2020 Changing the currently selected SwiftUI TabView tab

  struct OnboardingWizardView: View {
      @State var selectedTab = 0
      var body: some View {
          TabView(selection: $selectedTab) {
              Page1().tag(0)
              Page2().tag(1)
          }.tabViewStyle(PageTabViewStyle())
          .onAppear(perform: {
              DispatchQueue.main.asyncAfter(deadline: .now() + 2) {
                  withAnimation {
                      self.selectedTab = 1
                  }
              }
          })
          
      }
  }
  

• Nov 21, 2020 Delaying execution of code in SwiftUI

  DispatchQueue.main.asyncAfter(deadline: .now() + 2) {
      self.showProgress = false
  }
  

• Nov 21, 2020 VS Code Mac keyboard shortcut to stage changes

  Ctrl-Shift-G

• Nov 21, 2020 Making a SwiftUI Text fill the frame

  Text("Welcome")
      .font(.largeTitle)
      .frame(maxWidth: .infinity, maxHeight: .infinity)
  

• Nov 20, 2020 Resuming Xcode SwiftUI live preview

  To resume Xcode SwiftUI Live Preview press Option-Command-P

• Nov 20, 2020 Royalty free images for use in apps

  Royalty free images for use in apps: https://unsplash.com/

• Nov 20, 2020 Carousel view/multiple pages in SwiftUI

  To create a carousel view in SwiftUI, with multiple pages, use the TabView with .tabViewSyle set to PageTabViewStyle

• Nov 20, 2020 Mac Screenshot

  To open the screenshot utility: Shift Command 5

  Saves to Downloads

• Nov 19, 2020 Getting a # component from a URL

  From https://stackoverflow.com/a/57933248/3390

  func HandleCallback(url: URL) {
      var components = URLComponents()
      components.query = url.fragment
      
      accessToken = components.queryItems?.first(where: { $0.name == "access_token"})?.value
  }
  

• Nov 19, 2020 Formatting and delta dates in Swift

  let dateFormatter = DateFormatter()
  dateFormatter.dateFormat = "yyyy-MM-dd"
  let today = dateFormatter.string(from: Date())
  let monthAgo = dateFormatter.string(from: NSCalendar.current.date(byAdding: .month, value: -1, to: NSDate() as Date)!)
  

• Nov 19, 2020 SwiftUI Separator

  The SwiftUI separator is called a divider

• Nov 19, 2020 Formatting numbers in SwiftUI

  Text("\(food.loggedFood.amount, specifier: "%.1f") \(food.loggedFood.unit.plural)")
  

• Nov 19, 2020 A generic Swift REST call/decode function with a type as a parameter

  Pass the type of a generic parameter using T.Type

      var cancellables = [AnyCancellable]()
      
      fileprivate func GetData<T>(url: URL, token: String, resultType: T.Type,  callback: @escaping (T) -> Void) where T:Codable {
          var request = URLRequest(url: url)
          request.setValue("Bearer \(token)", forHTTPHeaderField: "Authorization")
          URLSession.shared.dataTaskPublisher(for: request)
              .tryMap() { element -> Data in
                  // let s = String(data: element.data, encoding: .utf8)
                  // print(s)
                  guard let httpResponse = element.response as? HTTPURLResponse,
                        httpResponse.statusCode == 200 else {
                      throw URLError(.badServerResponse)
                  }
                  return element.data
              }
              .decode(type: resultType, decoder: self.decoder)
              .receive(on: DispatchQueue.main)
              .sink(receiveCompletion: { v in
                  print(v)
              },
              receiveValue: { v in
                  callback(v)
              })
              .store(in: &self.cancellables)
      }
  

• Nov 19, 2020 Widening Jekyll content area

  If your minima Jekyll page width is too narrow, copy the _sass folder from your Jekyll installation to your web site folder, and then edit minima.scss to update the width:

  // Width of the content area
  $content-width:    2048px !default;
  

  You can find out where minima is installed using

  bundle info --path minima
  

• Nov 19, 2020 Launching Jekyll

  When trying to serve your site using jekyll and you get an error like this:

  jekyll serve
  ...
  /Library/Ruby/Gems/2.6.0/gems/bundler-2.1.4/lib/bundler/spec_set.rb:86:in `block in materialize': Could not find public_suffix-4.0.6 in any of the sources (Bundler::GemNotFound)
  

  don’t forget you need to use bundle exec jekyll serve

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