BleepingSwift

Fixing "-[OS_dispatch_mach_msg _setContext:]: unrecognized selector" on iOS 27

undefined (Mick MacCallum) — Sat, 13 Jun 2026 00:00:00 GMT

An app that ran fine for years suddenly hangs on the splash screen when you debug it on an iOS 27 device, with an OS_dispatch_mach_msg unrecognized selector in the console. Here is what causes it and the one-line fix.

How to Export and Use Xcode 27's Agent Skills in Claude Code

undefined (Mick MacCallum) — Tue, 09 Jun 2026 00:00:00 GMT

Xcode 27 ships seven official agent skills that capture Apple's own guidance on SwiftUI, testing, and security. Here's how to export them and use the same skills from Claude Code, Codex, or Cursor.

Fixing "Supported Deployment Target Versions is 15.0 to 27.0" in Xcode 27

undefined (Mick MacCallum) — Mon, 08 Jun 2026 00:00:00 GMT

Xcode 27 dropped support for deployment targets below iOS 15. If your build now fails with IPHONEOS_DEPLOYMENT_TARGET set to a lower value and a supported range of 15.0 to 27.0, here is why and how to fix it.

What's New in StoreKit for Xcode 27: Commitment Plans, Offer Codes, and More

undefined (Mick MacCallum) — Mon, 08 Jun 2026 00:00:00 GMT

Xcode 27 brings monthly subscriptions with a 12-month commitment, a reworked offer code redemption API, Bundles and Suites, and a unified App Review submission flow. Here is what each one changes for your code.

Getting Started with App Intents and Siri Shortcuts

undefined (Mick MacCallum) — Thu, 16 Apr 2026 00:00:00 GMT

Expose your app's features to Siri, Shortcuts, and Spotlight with App Intents, the Swift-native replacement for SiriKit in iOS 16 and later.

App Tracking Transparency in SwiftUI

undefined (Mick MacCallum) — Tue, 14 Apr 2026 00:00:00 GMT

A practical guide to App Tracking Transparency in iOS, covering the Info.plist usage description, the ATTrackingManager API, authorization statuses, and when to actually prompt the user from SwiftUI.

withCheckedContinuation vs withUnsafeContinuation in Swift

undefined (Mick MacCallum) — Sun, 12 Apr 2026 00:00:00 GMT

Continuations bridge completion-handler APIs into async/await. The checked variant catches the two ways you can get it wrong, and the unsafe one trusts you completely.

Module selectors in Swift 6.3

undefined (Mick MacCallum) — Sat, 11 Apr 2026 00:00:00 GMT

SE-0491 introduces the :: operator to disambiguate names that come from different modules. Here is when you actually need it and the gotchas worth knowing.

Data Races Swift 6 Still Can't Catch

undefined (Mick MacCallum) — Thu, 09 Apr 2026 00:00:00 GMT

Swift 6's data-race safety is real, but it has blind spots. Here are the places the compiler can't see, and how to stop treating a clean build as proof your code is thread safe.

OSAllocatedUnfairLock: The Type-Safe Replacement for os_unfair_lock

undefined (Mick MacCallum) — Tue, 07 Apr 2026 00:00:00 GMT

OSAllocatedUnfairLock wraps os_unfair_lock with a closure-based API that makes it impossible to forget to unlock and keeps the lock's storage alive for as long as you need it.

Fixing the fmt consteval Error in Xcode 26.4 for React Native

undefined (Mick MacCallum) — Mon, 06 Apr 2026 00:00:00 GMT

If your React Native build started failing after upgrading to Xcode 26.4 with a consteval error from the fmt library, here's a targeted Podfile fix that gets you back up and running.

Intercepting Network Requests in Swift with URLProtocol

undefined (Mick MacCallum) — Sun, 05 Apr 2026 00:00:00 GMT

URLProtocol is one of the oldest interception points in Foundation's networking stack. It lets you mock, log, or transform any URLSession request without touching the code that makes the request.

Async defer in Swift 6.4

undefined (Mick MacCallum) — Sat, 04 Apr 2026 00:00:00 GMT

SE-0493 finally lets you write defer { await cleanup() } in async functions, without spawning a detached task or threading cleanup logic through every return path.

Structured Logging in Swift with Logger and os_log

undefined (Mick MacCallum) — Fri, 03 Apr 2026 00:00:00 GMT

print is fine for scratch work, but production apps need categories, levels, and privacy redaction. Here is how the Logger API from the os module gives you all of that without much ceremony.

Task Cancellation Shields in Swift 6.4

undefined (Mick MacCallum) — Thu, 02 Apr 2026 00:00:00 GMT

Swift 6.4's withTaskCancellationShield lets cleanup code run to completion even after a task has been cancelled, without spawning extra unstructured tasks.

Using @concurrent in Swift 6.2

undefined (Mick MacCallum) — Thu, 26 Mar 2026 00:00:00 GMT

Swift 6.2 changes how async functions pick a thread by default. The new @concurrent attribute lets you explicitly opt into background execution when you actually need it.

Deep Linking and Universal Links Setup in iOS

undefined (Mick MacCallum) — Mon, 23 Mar 2026 00:00:00 GMT

How to set up custom URL schemes and Universal Links in iOS, handle incoming URLs in SwiftUI, and route users to the right screen.

Creating a @DefaultEmpty Property Wrapper for Codable in Swift

undefined (Mick MacCallum) — Fri, 20 Mar 2026 00:00:00 GMT

Build a @DefaultEmpty property wrapper that automatically defaults missing or null array fields to an empty array when decoding JSON in Swift.

Scheduling Local Notifications with UNUserNotificationCenter

undefined (Mick MacCallum) — Tue, 17 Mar 2026 00:00:00 GMT

A practical guide to scheduling and handling local notifications in iOS using UNUserNotificationCenter, from permission requests to actionable notification categories.

Building Custom Container Views in SwiftUI with Subviews

undefined (Mick MacCallum) — Sat, 14 Mar 2026 00:00:00 GMT

iOS 18 introduced public APIs for building custom container views that can decompose content into individual subviews. Learn how to use ForEach(subviews:), Group(subviews:), and ContainerValues.

How to Free Up Disk Space Used by Xcode

undefined (Mick MacCallum) — Fri, 13 Mar 2026 00:00:00 GMT

Xcode can consume 50GB+ of disk space over time. Here's how to reclaim storage by clearing caches, old simulators, device support files, and other accumulated cruft.

Getting Started with Swift Testing: Apple's Modern Test Framework

undefined (Mick MacCallum) — Thu, 12 Mar 2026 00:00:00 GMT

Swift Testing replaces XCTest with a cleaner macro-based API. Learn how to write tests with @Test, #expect, parameterized inputs, and traits in Xcode 16+.

Understanding Swift Macros: A Practical Guide

undefined (Mick MacCallum) — Wed, 11 Mar 2026 00:00:00 GMT

Swift macros generate code at compile time, reducing boilerplate and catching errors early. Learn how to use built-in macros and understand how custom macros work.

ControlWidgetButton for Control Center Widgets

undefined (Mick MacCallum) — Tue, 10 Mar 2026 00:00:00 GMT

Create interactive buttons for the Control Center using ControlWidgetButton and App Intents in iOS 18.

Error Handling in Swift: From Basics to Typed Throws

undefined (Mick MacCallum) — Mon, 09 Mar 2026 00:00:00 GMT

A practical guide to Swift error handling covering throw/try/catch fundamentals, custom error types, Result, async error patterns, and typed throws introduced in Swift 6.

Sensory Feedback and Haptics in SwiftUI

undefined (Mick MacCallum) — Sun, 08 Mar 2026 00:00:00 GMT

Add haptic feedback to your SwiftUI views using the sensoryFeedback modifier, with built-in support for success, error, impact, and selection feedback.

SwiftUI Animations: From Basics to KeyframeAnimator

undefined (Mick MacCallum) — Sat, 07 Mar 2026 00:00:00 GMT

A practical guide to SwiftUI animations covering implicit and explicit animations, spring physics, PhaseAnimator for multi-step sequences, and KeyframeAnimator for timeline-based control.

ViewThatFits for Adaptive Layouts in SwiftUI

undefined (Mick MacCallum) — Fri, 06 Mar 2026 00:00:00 GMT

Use ViewThatFits to automatically select the best layout variant based on available space, without writing manual size calculations.

Prevent Your Mac from Sleeping While Claude Code Works

undefined (Mick MacCallum) — Thu, 05 Mar 2026 00:00:00 GMT

Set up Claude Code to automatically keep your Mac awake during long tasks and let it sleep again when finished, using hooks and the caffeinate command.

The Difference Between Frame and Bounds in UIKit

undefined (Mick MacCallum) — Wed, 04 Mar 2026 00:00:00 GMT

Understand the key difference between a UIView's frame and bounds properties, and when to use each in your iOS apps.

Auto-Approve the Xcode MCP Connection Prompt with Claude Code Hooks

undefined (Mick MacCallum) — Tue, 03 Mar 2026 00:00:00 GMT

The Xcode MCP server connection prompt interrupts your flow every time you restart Claude Code or clear your session. Here's how to automate it away using hooks.

TaskGroup and Structured Concurrency Patterns in Swift

undefined (Mick MacCallum) — Mon, 02 Mar 2026 00:00:00 GMT

Master Swift's TaskGroup for parallel async work with proper cancellation, error handling, and result collection. Learn common patterns for batch operations and concurrent pipelines.

Typed Throws in Swift 6: Declaring Specific Error Types

undefined (Mick MacCallum) — Sun, 01 Mar 2026 00:00:00 GMT

Swift 6 introduces typed throws, letting you declare exactly which error types a function can throw. Learn how this improves API contracts and enables exhaustive error handling.

@Observable Macro in SwiftUI: Migrating from ObservableObject

undefined (Mick MacCallum) — Sat, 28 Feb 2026 00:00:00 GMT

Learn how to use Swift's @Observable macro introduced in iOS 17, understand its advantages over ObservableObject, and migrate your existing code to the modern observation system.

Swift Regex Builder: A Type-Safe DSL for Pattern Matching

undefined (Mick MacCallum) — Fri, 27 Feb 2026 00:00:00 GMT

Learn how to use Swift's RegexBuilder DSL to create readable, type-safe regular expressions with compile-time checking and strongly-typed captures.

Getting Started with Swift Charts

undefined (Mick MacCallum) — Thu, 26 Feb 2026 00:00:00 GMT

Learn how to create beautiful, interactive charts in SwiftUI using Apple's Swift Charts framework, from simple line charts to customized bar graphs.

Testing Expo and React Native on Device Over Local Network with Bonjour

undefined (Mick MacCallum) — Wed, 25 Feb 2026 00:00:00 GMT

Skip Expo Go and test your development build directly on a physical device using Bonjour for automatic network discovery.

Fixing Port 8081 Already in Use: Orphaned Metro Bundler Processes

undefined (Mick MacCallum) — Tue, 24 Feb 2026 00:00:00 GMT

When Metro won't start because port 8081 is already in use, you likely have an orphaned process. Here's how to find and kill it properly.

StoreKit 2 for In-App Purchases and Subscriptions

undefined (Mick MacCallum) — Mon, 23 Feb 2026 00:00:00 GMT

A practical guide to implementing in-app purchases and subscriptions with StoreKit 2, covering products, transactions, subscription status, and SwiftUI integration.

Swift System Metrics 1.0: Monitoring CPU, Memory, and More on the Server

undefined (Mick MacCallum) — Sat, 21 Feb 2026 00:00:00 GMT

Apple released Swift System Metrics 1.0, a package that collects process-level metrics like CPU time, memory usage, and file descriptors with a unified API across Linux and macOS.

Testing Push Notifications on iOS Simulators with xcrun simctl push

undefined (Mick MacCallum) — Fri, 20 Feb 2026 00:00:00 GMT

Learn how to test push notifications on iOS simulators without needing a device or server setup using xcrun simctl push.

@AppStorage vs UserDefaults vs SwiftData: Choosing the Right Persistence

undefined (Mick MacCallum) — Wed, 18 Feb 2026 00:00:00 GMT

Compare @AppStorage, UserDefaults, and SwiftData for persisting data in Swift apps. Learn when each approach makes sense and how to use them effectively.

Why Your Image Isn't Showing in a Live Activity

undefined (Mick MacCallum) — Tue, 17 Feb 2026 00:00:00 GMT

If your Live Activity renders a grey box instead of your image, the problem is almost certainly the image size. Here's how to fix it.

How to Preview Live Activities in SwiftUI

undefined (Mick MacCallum) — Sun, 15 Feb 2026 00:00:00 GMT

Use the #Preview macro to preview your Live Activity views directly in Xcode without running the full app.

Claude Code Auto Commit: How to Automatically Commit Changes as You Go

undefined (Mick MacCallum) — Sat, 14 Feb 2026 00:00:00 GMT

Claude Code can commit changes automatically while it works. Here's how to set that up using hooks, CLAUDE.md instructions, and the right permission configuration.

Debugging SwiftUI Previews in Xcode

undefined (Mick MacCallum) — Thu, 12 Feb 2026 00:00:00 GMT

When SwiftUI previews break, the error messages aren't always helpful. Here's how to debug them, clear caches, and get back to a working state.

Nullability Annotations in Objective-C

undefined (Mick MacCallum) — Tue, 10 Feb 2026 00:00:00 GMT

Objective-C's nullability annotations tell the compiler which pointers can be nil. They catch bugs at compile time and make your code bridge to Swift cleanly.

Using Vercel's Skills Library to Supercharge AI Agents for React Native

undefined (Mick MacCallum) — Mon, 09 Feb 2026 00:00:00 GMT

Vercel's Skills library lets you add reusable instruction sets to AI coding agents. Here's how to use it to make agents more effective for React Native development.

How to Change the Background Color of a View in SwiftUI

undefined (Mick MacCallum) — Sun, 08 Feb 2026 00:00:00 GMT

Learn different ways to set background colors on SwiftUI views, from simple color fills to gradients and materials.

I'm Really Excited About React Navigation v8

undefined (Mick MacCallum) — Sat, 07 Feb 2026 00:00:00 GMT

React Navigation v8 is in alpha and I'm genuinely excited. Native bottom tabs, smarter TypeScript inference, and a long-awaited fix for deep linking behind auth screens. This one's going to be good.

Understanding the "some" Keyword in Swift and SwiftUI

undefined (Mick MacCallum) — Sat, 07 Feb 2026 00:00:00 GMT

Learn what the "some" keyword means in Swift, how opaque return types work, and why SwiftUI uses "some View" everywhere.

Configuring Claude Code Permissions for React Native Development

undefined (Mick MacCallum) — Thu, 05 Feb 2026 00:00:00 GMT

React Native projects require running lots of shell commands. Here's how to configure Claude Code's permission system so you're not constantly approving the same operations.

How to Use Xcode's MCP Server to Build Xcode into Your AI Workflow

undefined (Mick MacCallum) — Wed, 04 Feb 2026 00:00:00 GMT

Xcode 26.3 ships with a built-in MCP server that exposes project structure, build actions, and test results to external AI tools. Here's how to set it up.

Lightweight Generics in Objective-C

undefined (Mick MacCallum) — Fri, 30 Jan 2026 00:00:00 GMT

Objective-C's lightweight generics let you specify element types for collections like NSArray. They catch type mismatches at compile time and improve Swift bridging.

SwiftUI vs UIKit: Which Should You Choose in 2026?

undefined (Mick MacCallum) — Wed, 28 Jan 2026 00:00:00 GMT

A practical guide to choosing between SwiftUI and UIKit in 2026, based on your project requirements, team experience, and the current state of both frameworks.

Choosing the Right Resource Isolation Strategy in Swift

undefined (Mick MacCallum) — Tue, 27 Jan 2026 00:00:00 GMT

Swift offers actors, GCD, and locks for thread safety. Each solves the same problem differently. Here's how to choose.

Resource Isolation in Swift Using Actors

undefined (Mick MacCallum) — Mon, 26 Jan 2026 00:00:00 GMT

Actors provide compile-time safety for shared mutable state in Swift. Here's when to use them and how they compare to older approaches.

Resource Isolation in Swift Using GCD

undefined (Mick MacCallum) — Sun, 25 Jan 2026 00:00:00 GMT

Grand Central Dispatch remains a practical choice for thread safety in Swift, especially when you need synchronous access or are working with legacy code.

Resource Isolation in Swift Using Locks

undefined (Mick MacCallum) — Sat, 24 Jan 2026 00:00:00 GMT

Locks offer the lowest overhead for thread synchronization in Swift. Here's when that matters and how to use them safely.

NavigationView vs NavigationStack: What Changed and Why

undefined (Mick MacCallum) — Wed, 21 Jan 2026 00:00:00 GMT

NavigationStack replaced NavigationView in iOS 16 with a more powerful programmatic navigation model. Here's what changed and how to migrate.

Async/Await Basics in Swift

undefined (Mick MacCallum) — Sat, 17 Jan 2026 00:00:00 GMT

A practical introduction to async/await in Swift, covering the fundamentals you need to write concurrent code that's both safe and readable.

Async/Await vs GCD in Swift: When to Use Each

undefined (Mick MacCallum) — Thu, 15 Jan 2026 00:00:00 GMT

Both async/await and Grand Central Dispatch solve concurrency problems, but they approach them differently. Here's how to choose between them.

Fixing 16KB Page Alignment Errors in React Native for Android

undefined (Mick MacCallum) — Tue, 13 Jan 2026 00:00:00 GMT

Google Play now requires 16KB page size support for Android apps. Here's how to fix alignment errors in your React Native project before your next release gets rejected.

Operator Precedence Gotchas When Moving Between Swift and Objective-C

undefined (Mick MacCallum) — Mon, 12 Jan 2026 00:00:00 GMT

A refactoring mishap with arithmetic expressions led me down the rabbit hole of operator precedence differences between Swift and Objective-C. Here's what to watch for.

Automatically Switch Node Versions with nvm for React Native Projects

undefined (Mick MacCallum) — Sun, 11 Jan 2026 00:00:00 GMT

Avoid cryptic build failures by setting up nvm to automatically use the right Node version when you cd into a project.

How to Change the Default Screenshot Folder on macOS

undefined (Mick MacCallum) — Sat, 10 Jan 2026 00:00:00 GMT

Stop cluttering your Desktop with screenshots. Here's how to save them somewhere else using Terminal or the Screenshot app.

Accessing the Camera Roll in SwiftUI

undefined (Mick MacCallum) — Sun, 04 Jan 2026 00:00:00 GMT

Learn how to access photos from the camera roll in SwiftUI, including required permissions, Info.plist configuration, and using PhotosPicker for iOS 16+ or UIImagePickerController for earlier versions.

Detecting When a Screenshot is Taken in SwiftUI

undefined (Mick MacCallum) — Fri, 02 Jan 2026 00:00:00 GMT

Learn how to detect when users take screenshots in your SwiftUI app by observing UIApplication notifications.

Prevent macOS from Creating .DS_Store Files on Network and USB Drives

undefined (Mick MacCallum) — Tue, 30 Dec 2025 00:00:00 GMT

Stop macOS from littering .DS_Store files on network shares and USB drives with a simple Terminal command. Keep your external storage clean and your repositories tidy.

Detect Successful Share Sheet Completion in SwiftUI

undefined (Mick MacCallum) — Sun, 28 Dec 2025 00:00:00 GMT

Learn how to detect when a user successfully shares content using a share sheet in SwiftUI by wrapping UIActivityViewController.

Prevent Drag-to-Dismiss on SwiftUI Sheets

undefined (Mick MacCallum) — Mon, 22 Dec 2025 00:00:00 GMT

Learn how to prevent users from dismissing modal sheets by swiping down in SwiftUI using interactiveDismissDisabled.

Building Interactive Glass Controls in SwiftUI

undefined (Mick MacCallum) — Sun, 21 Dec 2025 00:00:00 GMT

Make your glass elements respond to touch with scaling, shimmer effects, and touch-point illumination using the interactive() modifier and glass button styles.

Rounding Corners in SwiftUI: From cornerRadius to clipShape

undefined (Mick MacCallum) — Sat, 20 Dec 2025 00:00:00 GMT

The cornerRadius modifier is deprecated in iOS 17. Here's how to use clipShape, RoundedRectangle, and the new ConcentricRectangle to round corners the modern way.

Creating Morphing Glass Transitions with glassEffectID

undefined (Mick MacCallum) — Fri, 19 Dec 2025 00:00:00 GMT

The glassEffectID modifier enables glass views to smoothly morph into one another during state changes, creating fluid transitions that feel native to iOS 26.

Disable Touches with allowsHitTesting in SwiftUI

undefined (Mick MacCallum) — Thu, 18 Dec 2025 00:00:00 GMT

Learn how to use the allowsHitTesting modifier to make views ignore touches, letting taps pass through to elements behind them.

Coordinating Glass Elements with GlassEffectContainer

undefined (Mick MacCallum) — Mon, 15 Dec 2025 00:00:00 GMT

When you have multiple glass elements that should blend and animate together, GlassEffectContainer coordinates their rendering for seamless visual results.

Getting Started with Liquid Glass in SwiftUI

undefined (Mick MacCallum) — Sun, 14 Dec 2025 00:00:00 GMT

iOS 26 introduces Liquid Glass, a translucent design language for navigation elements. Here's how to apply the glassEffect modifier to your custom views.

Fixing "No Such Module" Errors in Xcode

undefined (Mick MacCallum) — Wed, 10 Dec 2025 00:00:00 GMT

When Xcode says it can't find a module you've clearly installed, the problem is usually in your build configuration, not your package manager.

Simulating Device Conditions in Xcode for Real-World Testing

undefined (Mick MacCallum) — Thu, 04 Dec 2025 00:00:00 GMT

Learn how to use Xcode's Device Conditions feature to simulate thermal state and network conditions to test your app under real-world stress scenarios.

How to Round Specific Corners of a View in SwiftUI

undefined (Mick MacCallum) — Wed, 26 Nov 2025 00:00:00 GMT

Learn how to round only certain corners of a SwiftUI view using UnevenRoundedRectangle, custom shapes, and clipShape.

How to Resize an Image in SwiftUI

undefined (Mick MacCallum) — Tue, 25 Nov 2025 00:00:00 GMT

Learn how to resize images in SwiftUI using resizable(), frame(), and different content modes like scaledToFit and scaledToFill.

How to Add an Activity Indicator (Spinner) in SwiftUI

undefined (Mick MacCallum) — Sat, 22 Nov 2025 00:00:00 GMT

Learn how to show loading spinners in SwiftUI using ProgressView, including customization options and common loading patterns.

Detecting Shake Gestures in SwiftUI

undefined (Mick MacCallum) — Sat, 22 Nov 2025 00:00:00 GMT

Learn how to detect when users shake their device in SwiftUI by bridging to UIKit's motion events and creating a reusable view modifier.

Fixing iOS Simulator That Won't Launch or Boot

undefined (Mick MacCallum) — Tue, 18 Nov 2025 00:00:00 GMT

When the iOS Simulator refuses to launch, gets stuck booting, or shows a black screen, here's how to diagnose and fix it.

Scheduling Alarms with AlarmKit

undefined (Mick MacCallum) — Sat, 15 Nov 2025 00:00:00 GMT

Learn how to use AlarmKit to schedule alarms and countdown timers that appear on the Lock Screen and Dynamic Island on iOS 26.

Supporting Dark Mode in a SwiftUI App

undefined (Mick MacCallum) — Fri, 14 Nov 2025 00:00:00 GMT

Learn how to properly support dark mode in SwiftUI using semantic colors, adaptive color assets, and color scheme detection.

Using SF Symbols in SwiftUI

undefined (Mick MacCallum) — Thu, 13 Nov 2025 00:00:00 GMT

Learn how to use SF Symbols in your SwiftUI apps, including sizing, coloring, animations, and finding the right symbol for your needs.

@State vs @Binding in SwiftUI: When to Use Each

undefined (Mick MacCallum) — Mon, 10 Nov 2025 00:00:00 GMT

Understand the difference between @State and @Binding in SwiftUI, when to use each, and how they work together to manage data flow between views.

Reading Your App's Age Rating with StoreKit's ageRatingCode

undefined (Mick MacCallum) — Sat, 08 Nov 2025 00:00:00 GMT

Learn how to use AppStore.ageRatingCode to read your app's current age rating and react to rating changes for parental consent compliance.

Fixing Xcode Indexing That's Stuck or Slow

undefined (Mick MacCallum) — Mon, 03 Nov 2025 00:00:00 GMT

When Xcode's indexing gets stuck or takes forever, your autocomplete and jump-to-definition stop working. Here's how to get it unstuck.

Add Spacing to Toolbars with ToolbarSpacer in SwiftUI

undefined (Mick MacCallum) — Thu, 30 Oct 2025 00:00:00 GMT

Learn how to use ToolbarSpacer to add fixed and flexible spacing between toolbar items in SwiftUI, new in iOS 26.

Working with Optional ObservableObject in SwiftUI

undefined (Mick MacCallum) — Sat, 25 Oct 2025 00:00:00 GMT

Learn different approaches for handling optional ObservableObject instances in SwiftUI, from conditional rendering to wrapper patterns.

Defensive Coding with NSError in Objective-C

undefined (Mick MacCallum) — Wed, 22 Oct 2025 00:00:00 GMT

NSError is the standard error handling mechanism in Objective-C, but using it defensively requires more than just passing a pointer. Learn patterns that prevent crashes and make debugging easier.

Using Failable Initializers to Handle Optionals in SwiftUI Views

undefined (Mick MacCallum) — Wed, 22 Oct 2025 00:00:00 GMT

Failable initializers offer a cleaner alternative to if-let statements when your SwiftUI views depend on optional data.

Control Sheet Height with presentationDetents in SwiftUI

undefined (Mick MacCallum) — Wed, 15 Oct 2025 00:00:00 GMT

Learn how to use the presentationDetents modifier to control sheet heights in SwiftUI, creating interactive bottom sheets similar to Apple Maps and Music.

Fixing SwiftUI Previews That Won't Load

undefined (Mick MacCallum) — Wed, 08 Oct 2025 00:00:00 GMT

When SwiftUI previews fail with cryptic errors or just spin forever, here's how to diagnose and fix the most common causes.

Building Child-Safe Communication Features with PermissionKit

undefined (Mick MacCallum) — Fri, 03 Oct 2025 00:00:00 GMT

PermissionKit lets children request parental permission to communicate with new contacts directly through Messages. Here's how to integrate it into your social or messaging app to create safer communication experiences.

Control Tappable Area with contentShape in SwiftUI

undefined (Mick MacCallum) — Sun, 28 Sep 2025 00:00:00 GMT

Learn how to use the contentShape modifier to expand or customize the tappable area of your SwiftUI views, making buttons and interactive elements more user-friendly.

Understanding Safe Areas in SwiftUI

undefined (Mick MacCallum) — Mon, 22 Sep 2025 00:00:00 GMT

Safe areas keep your content visible and interactive. Here's how they work in SwiftUI and when you should ignore them.

Detecting When App Enters Background and Saving State in SwiftUI

undefined (Mick MacCallum) — Sat, 13 Sep 2025 00:00:00 GMT

Learn how to detect app lifecycle changes in SwiftUI, save state when your app enters the background, and restore it when users return, using scenePhase and UIApplication notifications.

Previewing Partially Generated Content with Foundation Models in SwiftUI

undefined (Mick MacCallum) — Thu, 11 Sep 2025 00:00:00 GMT

When building UIs that stream AI-generated content using Apple's Foundation Models framework, testing intermediate states in Xcode Previews requires some creative workarounds. Here's how to preview partially generated content without calling the actual model.

Using Custom Fonts in SwiftUI

undefined (Mick MacCallum) — Fri, 05 Sep 2025 00:00:00 GMT

How to add custom fonts to your SwiftUI app, use system font variants, and ensure your typography scales properly with Dynamic Type.

Centering Views in SwiftUI

undefined (Mick MacCallum) — Tue, 19 Aug 2025 00:00:00 GMT

Understanding the difference between frame alignment and stack alignment is the key to centering views exactly where you want them in SwiftUI.

Adding Horizontal Padding to TextEditor in SwiftUI with contentMargins

undefined (Mick MacCallum) — Tue, 12 Aug 2025 00:00:00 GMT

Learn how to add horizontal padding inside a TextEditor without affecting the scrollbar using the contentMargins modifier introduced in iOS 17.

Detecting Low Power Mode in SwiftUI and Adapting UI Performance

undefined (Mick MacCallum) — Fri, 08 Aug 2025 00:00:00 GMT

Learn how to detect when users enable Low Power Mode and automatically reduce animations, refresh rates, and visual effects to preserve battery life in your SwiftUI app.

Presenting Multiple Sheets in SwiftUI

undefined (Mick MacCallum) — Fri, 18 Jul 2025 00:00:00 GMT

How to present a second sheet from within an already-presented sheet in SwiftUI.

Symbolicating Swift Crash Reports in Xcode

undefined (Mick MacCallum) — Fri, 11 Jul 2025 00:00:00 GMT

Learn how to symbolicate crash logs from App Store Connect and Xcode Cloud to debug production crashes effectively.

Adding an App Delegate to a SwiftUI App

undefined (Mick MacCallum) — Sun, 06 Jul 2025 00:00:00 GMT

Learn how to integrate UIKit's App Delegate into your SwiftUI app for handling app lifecycle events and system callbacks.

Access Environment Values in View Extensions

undefined (Mick MacCallum) — Sat, 05 Jul 2025 00:00:00 GMT

Learn how to access SwiftUI environment values in View extensions using ViewModifiers for clean, reusable code.

How to generate QR codes in SwiftUI

undefined (Mick MacCallum) — Thu, 03 Jul 2025 00:00:00 GMT

Learn how to create and display QR codes in SwiftUI using Core Image filters.

How to search SF Symbols in Xcode

undefined (Mick MacCallum) — Wed, 02 Jul 2025 00:00:00 GMT

Learn how to search SF Symbols in Xcode.

Building a Floating Action Button (FAB) that Respects Keyboard in SwiftUI

undefined (Mick MacCallum) — Fri, 27 Jun 2025 00:00:00 GMT

Learn how to create a Material Design-style floating action button in SwiftUI that intelligently moves above the keyboard and avoids blocking text input fields.

Building a Pull-to-Load-More ScrollView in SwiftUI

undefined (Mick MacCallum) — Fri, 20 Jun 2025 00:00:00 GMT

How to detect when users scroll to the bottom of a list and automatically load more content.

Managing Keyboard Toolbar Items in SwiftUI (iOS 15+)

undefined (Mick MacCallum) — Sun, 15 Jun 2025 00:00:00 GMT

Learn how to add custom toolbar buttons above the keyboard in SwiftUI using the .toolbar modifier with keyboard placement for Done buttons, formatting controls, and more.

Preventing Screenshot Capture in SwiftUI Views

undefined (Mick MacCallum) — Thu, 05 Jun 2025 00:00:00 GMT

Learn how to prevent users from taking screenshots of sensitive content in your SwiftUI app using field-level security and UIKit bridging for financial, medical, or private data protection.

Creating an iMessage-Style Input Accessory View in SwiftUI

undefined (Mick MacCallum) — Sun, 25 May 2025 00:00:00 GMT

Learn how to create a custom input accessory view that stays above the keyboard, similar to iMessage's input bar.

Finding the Top View Controller in Swift

undefined (Mick MacCallum) — Thu, 15 May 2025 00:00:00 GMT

How to traverse the view controller hierarchy to find the currently visible view controller.

Implementing Pull-to-Refresh Without List in SwiftUI

undefined (Mick MacCallum) — Thu, 08 May 2025 00:00:00 GMT

Learn how to add pull-to-refresh functionality to custom ScrollViews in SwiftUI without using List, perfect for custom layouts and complex scroll content.

Creating Skeleton Loading Views (Shimmer Effect) in SwiftUI

undefined (Mick MacCallum) — Tue, 29 Apr 2025 00:00:00 GMT

Learn how to build skeleton loading screens with animated shimmer effects in SwiftUI using gradients, AnimatableModifier, and reusable view modifiers for a polished loading experience.

Inspecting all SwiftUI Environment Values

undefined (Mick MacCallum) — Sat, 19 Apr 2025 00:00:00 GMT

Learn how to dump all SwiftUI environment values for debugging purposes.

Showing a relative "Time ago" date in SwiftUI

undefined (Mick MacCallum) — Fri, 18 Apr 2025 00:00:00 GMT

Learn how to display human-readable relative timestamps like "5 minutes ago" or "yesterday" using RelativeDateTimeFormatter in your SwiftUI apps.

Generating a Random Emoji in Swift

undefined (Mick MacCallum) — Sat, 12 Apr 2025 00:00:00 GMT

How to generate random emoji characters in Swift using Unicode scalar ranges.

Implementing Undo/Redo in SwiftUI with UndoManager

undefined (Mick MacCallum) — Sat, 05 Apr 2025 00:00:00 GMT

Learn how to implement undo/redo functionality in SwiftUI using UndoManager, including environment injection, registering actions, and creating undo buttons for professional editing experiences.

Getting Current Disk Usage in Swift

undefined (Mick MacCallum) — Thu, 20 Mar 2025 00:00:00 GMT

How to check available and total disk space on iOS devices using URL resource values.

Firebase Crashlytics dSYM files not uploading using Xcode 15+

undefined (Mick MacCallum) — Mon, 17 Mar 2025 00:00:00 GMT

Learn how to fix the Firebase Crashlytics dSYM files not properly being uploaded to Firebase after upgrading to Xcode 15/16.

Accessing Environment Variables in Swift

undefined (Mick MacCallum) — Sun, 09 Mar 2025 00:00:00 GMT

Learn how to access and configure environment variables in Swift applications for configuration management, API keys, and feature toggles.

Aligning Text in SwiftUI

undefined (Mick MacCallum) — Thu, 13 Feb 2025 00:00:00 GMT

Learn how to align single and multiline text in SwiftUI.

How to make a SwiftUI List scroll automatically?

undefined (Mick MacCallum) — Wed, 12 Feb 2025 00:00:00 GMT

Learn how to use ScrollViewReader and ScrollViewProxy to scroll a SwiftUI list to a specific item automatically.

Detect when a context menu is open in SwiftUI

undefined (Mick MacCallum) — Mon, 10 Feb 2025 00:00:00 GMT

Learn how to detect when a context menu is open in SwiftUI.

Creating a WebView with a transparent background in SwiftUI

undefined (Mick MacCallum) — Mon, 10 Feb 2025 00:00:00 GMT

Learn how to create a WebView/WKWebView with a transparent/clear background in SwiftUI.

Adding a TextField to an Alert in SwiftUI

undefined (Mick MacCallum) — Sun, 09 Feb 2025 00:00:00 GMT

Learn how to accept user input in an alert using TextField or SecureField.

Different Ways to Dismiss the Keyboard in React Native

undefined (Mick MacCallum) — Sun, 19 Jan 2025 00:00:00 GMT

The keyboard doesn't always dismiss itself when you expect it to. Here are several approaches to dismissing it programmatically and through user interaction.

Adding a character limit to a TextEditor or TextField in SwiftUI

undefined (Mick MacCallum) — Tue, 17 Dec 2024 00:00:00 GMT

Learn how to create a modifier that limits the characters that can be entered in a TextEditor or TextField view in SwiftUI.

How to scale text to fit its parent view with SwiftUI

undefined (Mick MacCallum) — Thu, 12 Dec 2024 00:00:00 GMT

Learn the ways to scale a text view's font size to fit its parent view in SwiftUI.

How to display a GIF from a URL in SwiftUI

undefined (Mick MacCallum) — Wed, 11 Dec 2024 00:00:00 GMT

Learn how to use a WKWebView as a quick way to load a GIF from a URL and display it in a SwiftUI view.

Creating custom styles for DisclosureGroup views

undefined (Mick MacCallum) — Tue, 10 Dec 2024 00:00:00 GMT

Learn how to use DisclosureGroupStyle to create custom DisclosureGroup views in SwiftUI.

How to get the name of an emoji in Swift

undefined (Mick MacCallum) — Sun, 08 Dec 2024 00:00:00 GMT

Learn how to use kCFStringTransformToUnicodeName to get the system name for any emoji.

Preventing the software keyboard from dismissing on iOS simulators

undefined (Mick MacCallum) — Sun, 08 Dec 2024 00:00:00 GMT

Learn how to prevent typing with your physical keyboard from dismissing the software keyboard when running your Swift app in the iOS simulator.

nil vs Nil vs NULL vs NSNull in Objective-C

undefined (Mick MacCallum) — Mon, 18 Nov 2024 00:00:00 GMT

Objective-C has four ways to represent nothing. Understanding when to use each prevents subtle bugs and clarifies your code's intent.

Detecting if SwiftUI is running in a Preview in Xcode

undefined (Mick MacCallum) — Tue, 08 Oct 2024 00:00:00 GMT

Learn how to detect if a SwiftUI app is running in a Xcode Preview.

Fixing CocoaPods "Unknown ISA PBXFileSystemSynchronizedRootGroup" Error

undefined (Mick MacCallum) — Tue, 08 Oct 2024 00:00:00 GMT

How to resolve the pod install error caused by Xcode 16's new folder-based group structure.

How to force navigation bar to show background in SwiftUI?

undefined (Mick MacCallum) — Mon, 07 Oct 2024 00:00:00 GMT

Learn how to force the navigation bar to show a background color in SwiftUI.

Using DisclosureGroup to hide and show content

undefined (Mick MacCallum) — Sun, 06 Oct 2024 00:00:00 GMT

How to use the SwiftUI DisclosureGroup view to create collapsable content.

All the Ways to Add Elements to an Array in Swift

undefined (Mick MacCallum) — Sun, 15 Sep 2024 00:00:00 GMT

A practical guide to the different methods for adding single elements, multiple elements, and inserting at specific positions in Swift arrays.

How to Access the App Delegate in Swift

undefined (Mick MacCallum) — Mon, 09 Sep 2024 00:00:00 GMT

Learn how to access your app's App Delegate from anywhere in your Swift code, including from SwiftUI views.

How to Replace Characters in a String in Swift

undefined (Mick MacCallum) — Tue, 20 Aug 2024 00:00:00 GMT

Learn multiple approaches to replace characters and substrings in Swift strings, from simple replacements to pattern-based transformations.

Key-Value Observing Deep Dive

undefined (Mick MacCallum) — Tue, 12 Dec 2023 00:00:00 GMT

KVO lets you observe property changes without delegation or notifications. Here's how it works under the hood and how to use it correctly.

Blocks - Closures Before Swift Existed

undefined (Mick MacCallum) — Fri, 17 Nov 2023 00:00:00 GMT

Before Swift closures, Objective-C had blocks. The syntax is different, but the power is the same. Here's how to use them effectively.

The NSObject Class Hierarchy Explained

undefined (Mick MacCallum) — Thu, 05 Oct 2023 00:00:00 GMT

Every Objective-C class inherits from NSObject (usually). Here's what NSObject provides and why it matters for every object you create.

Categories vs Class Extensions in Objective-C

undefined (Mick MacCallum) — Tue, 29 Aug 2023 00:00:00 GMT

Both let you add methods to classes, but categories and class extensions serve different purposes. Here's when to use each.

Message Passing - The Heart of Objective-C

undefined (Mick MacCallum) — Tue, 11 Jul 2023 00:00:00 GMT

Unlike C++ virtual methods, Objective-C uses dynamic message passing. Understanding this mechanism unlocks the language's full power.

Understanding Retain Cycles in Objective-C

undefined (Mick MacCallum) — Thu, 18 May 2023 00:00:00 GMT

Retain cycles are the most common memory leak in Objective-C. Learn how they form, how to detect them, and patterns that prevent them.

Namespacing in Objective-C - The Prefix Problem

undefined (Mick MacCallum) — Thu, 06 Apr 2023 00:00:00 GMT

Objective-C lacks namespaces, so the community invented conventions. Here's how prefixes and other patterns help avoid collisions in a flat symbol space.

The 10 Longest Symbol Names in Apple's Frameworks

undefined (Mick MacCallum) — Tue, 14 Feb 2023 00:00:00 GMT

Objective-C is famous for verbose naming. Let's celebrate (or mourn) the longest method and class names hiding in Apple's standard libraries.

Why Objective-C Has try-catch But Nobody Uses It

undefined (Mick MacCallum) — Fri, 27 Jan 2023 00:00:00 GMT

Objective-C supports exception handling with @try/@catch, but the community settled on NSError pointers instead. Here's why.

Ways to Shoot Yourself in the Foot with Method Swizzling

undefined (Mick MacCallum) — Thu, 03 Nov 2022 00:00:00 GMT

Swizzling is powerful but dangerous. Here are the common pitfalls and how to avoid turning your clever hack into a debugging nightmare.

The Power of Method Swizzling in Objective-C

undefined (Mick MacCallum) — Mon, 19 Sep 2022 00:00:00 GMT

Method swizzling lets you replace method implementations at runtime. Here's how it works and when this powerful technique shines.

Class Clusters in Objective-C - The Pattern Behind Foundation

undefined (Mick MacCallum) — Fri, 08 Jul 2022 00:00:00 GMT

Understand the class cluster pattern that makes NSString, NSArray, and NSDictionary work, and learn how to implement your own.

NSTaggedPointerString - The Hidden Optimization You've Never Heard Of

undefined (Mick MacCallum) — Sun, 22 May 2022 00:00:00 GMT

Discover how the Objective-C runtime secretly stores small strings directly in pointer values, eliminating heap allocations entirely.

Barrier Queues in GCD - Thread-Safe Collections Without Locks

undefined (Mick MacCallum) — Tue, 15 Mar 2022 00:00:00 GMT

Learn how dispatch barrier queues provide elegant reader-writer synchronization in Objective-C without explicit locks or semaphores.