If you have spent enough time with SwiftUI, you have likely run into the dreaded ghost re-render: your view appears, nothing in your data model has visibly changed, but body fires twice. Recently, I embarked on a deep-dive investigation using LLDB, stack traces, and Self._printChanges() to uncover why a presented AlertContent view was evaluating its body twice upon Read more
If you’ve built modals or alerts in SwiftUI, chances are high you started with the classic .alert(“Title”, isPresented: $isShowingAlert). It’s the default approach shown in most basic tutorials. However, as soon as your alert needs to display dynamic data or work with isolated Core Data child contexts and draft objects, the isPresented pattern quickly Read more
If you have ever built an editing flow in SwiftUI, you know the classic requirement: Changes should only commit when the user explicitly hits “Done.” If they hit “Cancel,” any experimental property modifications should instantly vanish. In Core Data, developers used nested child contexts to stage edits. In SwiftData, direct equivalents to Read more
If you’ve spent enough time building complex forms driven by optional data structures, like a Core Data staging context or a CloudKit configuration schema, you have likely run headfirst into a frustrating race condition. You have a dynamic form row that toggles open when data exists, and a clear button Read more
If you were a SwiftUI developer in the summer of 2023, you remember the feeling. WWDC had just dropped. The heavens opened, and out came the Observation Framework. We were told to delete our ObservableObject protocols, throw @Published in the bin, and embrace the clean, macro-powered future of @Observable. But then, iOS 17 Beta 5 happened. And it Read more
This blog post was written with the assistance of ChatGPT. When integrating UIKit components into SwiftUI using UIViewRepresentable, you might come across the context.environment property. While it looks simple on the surface, it hides a powerful mechanism: environment-driven updates. In this post, we’ll explore what context.environment does, how SwiftUI tracks it, and how it can cause Read more
To upgrade old Combine code in an ObservableObject that had its lifetime tied to a SwiftUI View using @StateObject we can replace it with .task and since async/await gives us a lifetime like a reference type we can do away with the object altogether. In the Combine version of the Read more
The built-in @Query does not currently support dynamic changes, instead we can use @DynamicQuery from the SwiftDataX open-source package to achieve it. The query declaration looks like this: By default that will load all Prospect model objects, sorting them by name. If the fetchDescriptor property is later changed and this View is Read more
SwiftUI’s design takes advantage of equality to decide if things should be updated. Measurement (backed by NSMeasurement) has something interesting in its Equatable implementation: This means that 0kg is equal to 0g despite their unit being different. This makes sense for comparing weights but not for using it to decide Read more
Reposted from: https://forums.swift.org/t/how-to-use-observation-to-actually-observe-changes-to-a-property/67591/18 I thought I’d share an example of how I am currently using it. I wanted to make an object that maintains a sorted order of the main model’s objects. I used withObservationTracking to update if either the sort order local to this object is changed or if the particular Read more