mbrandonw

/*
 The @AppStorage property wrapper does not fully work unless installed
 directly in a view. In particular, it does not work when used in an 
 observable object.

 Paste the following into a fresh project, run it in the simulator,
 and notice that tapping the "Toggle model.isOn" button causes the view
 to update propertly, but tapping the "Toggle UserDefaults directly" 
 button does not. This means that writing directly to user defaults 
 does cause @AppStorage to update, _unless_ @AppStorage is used in the

mbrandonw

 struct SyncUpDetailView: View {
-  @Bindable var model: SyncUpDetailModel
+  @Bindable var store: StoreOf<SyncUpDetail>
 
   var body: some View {
     Form {
       Section {
         Button {
-          model.startMeetingButtonTapped()
+          store.send(.startMeetingButtonTapped)

mbrandonw

# FB12969716

// FB: `Form` and 
//
// Paste this into a fresh SwiftUI project's ContentView.swift to see a bug with `Form` views with
// conditional child views that use `@State`.
//
//  1. Tap "Toggle" to show the child view with a new model
//  2. Tap "+" in the child view to increment the model's state from 0 to another number
//  3. Tap "Toggle" two times to hide the child and then show it again

mbrandonw

import SwiftUI

@Observable
class CounterModel {
  var count = 0
}
struct CounterView: View {
  let model: CounterModel
  var body: some View {
    Text(self.model.count.description)

mbrandonw

Cannot use #if canImport with @ObservationIgnored

#66629

mbrandonw

Unbound memory growth when using existential with primary associated type in SwiftUI view

FB12101395, apple/swift issue #64974

Run the following code in a simulator, tap the “Go” button, and notice that the application freezes:

import SwiftUI

struct ContentView: View {
 var body: some View {

mbrandonw

// A fix for https://github.com/AvdLee/TaskGroupsResultBuilder/blob/main/TaskGroups/TaskResultBuilder.swift
// to handle cancellation.

@resultBuilder
struct TaskBuilder {
  static func buildExpression<Success: Sendable>(_ task: Task<Success, Never>) -> [Task<Success, Never>] {
    [task]
  }

  static func buildBlock<Success: Sendable>(_ tasks: [Task<Success, Never>]...) -> [Task<Success, Never>] {

mbrandonw

Automatically add -ObjC when linking static libraries that contain Swift or ObjC code

FB11788325

Is it possible for Xcode/linker to automatically link -ObjC when linking static libraries that contain Swift or ObjC code?

Without that it is possible for a protocol conformance in a static library to be seemingly stripped from the library. For example, if you have the following protocol hierarchy in a static library:

protocol P {}

mbrandonw

TextField writes to binding twice

FB10492871

The binding provided to a TextField is written to twice for each keystroke.

Run the following code in a SwiftUI application and type into the text field to reproduce:

import SwiftUI

mbrandonw

NotificationCenter.Notifications does not cooperatively cancel

FB10473067

When the following code is run in a playground or in an application:

let task = Task {
  for await _ in await NotificationCenter.default.notifications(named: UIApplication.userDidTakeScreenshotNotification) {
  }
 print(#line, "Sequence finished")