If you attempt to init another instance of CLMonitor with the same name it crashes with: Since I wanted to use the same monitor from different tasks I needed to turn it into a singleton and came up with this: This allows this kind of thing to work without crashing: Read more
Following on from my previous post on this topic I found a forum post with someone struggling to build a calculator using @Observable and thought maybe my technique of wrapping withObservationTracking in AsyncStream might help and came up with the code below which appears to work. Obviously this code comes Read more
I noticed a snag when using NavigationLink(value:label:) and .navigationDestination(for:destination:) with the new @Observable vs the old Combine ObservableObject (which “just worked™️”). There are 2 compilation errors: Fortunately it is relatively simple to add Hashable conformance to an @Observable class by implementing a static func == and a func hash that Read more
In SwiftIUI, when requiring the reference semantics of a class and wanting to upgrade from Combine’s ObservableObject and @StateObject to the new @Observable it requires a bit more work to get the life-cycle correct. The reason for this is we have to store the object in @State which is designed Read more
Sharing @AppStorage without having to pass it into every feature of the app is simply done in the same way it’s done for anything else you want to share: EnvironmentKey. It lets you share a source of truth into a View hierarchy without needing to pass it into every View. Read more
I came across this interesting Stack Overflow question How can I make a simple circular button in SwiftUI in macOS? It’s interesting because all of the proposed solutions required hard-coding a frame size. I decided to experiment with how to make a circle that dynamically resizes to the size of Read more
Learning SwiftUI can be tricky because it has a very different design to previous UI frameworks. Many make the mistake of trying to apply old design patterns which are not really compatible because of SwiftUI’s use of value semantics and its diffing algorithm – most developers from UIKit, Java or Read more
I came across an interesting Stack Overflow question about how to support List selection of different types when using NavigationSplitView when in regular width, e.g. on iPad landscape. This problem doesn’t arise with NavigationStackView because multiple ForEach can simply iterate an array of each value and then there is a Read more
If you need to show multiple sheets in SwiftUI it is best to use the framework features to your advantage. Rather than try to abstract the problem into a generic coordinator object, which you then have to unbundle again to customise each circumstance, you can simply create multiple small subview Read more
I designed a better way to nest property wrappers than other examples I’ve seen in this article and this Stack Overflow question. The sample below is a redesigned version of the code in the question, which I also posted as an answer. Rather than use multiple property wrappers on the Read more