// 182 articles available
Set REACT_NATIVE_PACKAGER_HOSTNAME to your Mac's .local name so an Expo dev build on a physical device finds Metro over Bonjour, no Expo Go needed.
Kill port 8081 by finding the PID with lsof -i :8081 and running kill on it. Here's why an orphaned Metro bundler holds the port and how to avoid it.
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.
Implement in-app purchases and subscriptions with StoreKit 2: load products, handle transactions, check entitlements, and wire it all into SwiftUI.
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.
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.
Preview Live Activity views right in Xcode without launching the app. Use the #Preview macro with content states to iterate on your UI fast.
In Claude Code, commit changes means running git commit on the edits it made. Here's how to make it commit automatically with hooks or CLAUDE.md.
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.
Objective-C's lightweight generics let you specify element types for collections like NSArray<NSString *>. They catch type mismatches at compile time and improve Swift bridging.
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.
Use Objective-C nullability annotations like _Nullable and NS_ASSUME_NONNULL_BEGIN to catch nil bugs at compile time and bridge cleanly to Swift.
Vercel's skills give AI coding agents reusable React Native instructions. Add them with npx skills add vercel-labs/agent-skills and write your own.
Learn different ways to set background colors on SwiftUI views, from simple color fills to gradients and materials.
A practical introduction to async/await in Swift, covering the fundamentals you need to write concurrent code that's both safe and readable.
Both async/await and Grand Central Dispatch solve concurrency problems, but they approach them differently. Here's how to choose between them.
The keyboard doesn't always dismiss itself when you expect it to. Here are several approaches to dismissing it programmatically and through user interaction.
NavigationStack replaced NavigationView in iOS 16 with a more powerful programmatic navigation model. Here's what changed and how to migrate.
nil is a null object pointer, Nil a null class, NULL a null C pointer, and NSNull a placeholder object for collections. Here's when to use each one.
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.
Learn what the "some" keyword means in Swift, how opaque return types work, and why SwiftUI uses "some View" everywhere.
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.
Learn how to show loading spinners in SwiftUI using ProgressView, including customization options and common loading patterns.
Learn how to use AppStore.ageRatingCode to read your app's current age rating and react to rating changes for parental consent compliance.
Learn how to use the allowsHitTesting modifier to make views ignore touches, letting taps pass through to elements behind them.
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.
Learn how to properly support dark mode in SwiftUI using semantic colors, adaptive color assets, and color scheme detection.
Learn how to detect when users shake their device in SwiftUI by bridging to UIKit's motion events and creating a reusable view modifier.
When you have multiple glass elements that should blend and animate together, GlassEffectContainer coordinates their rendering for seamless visual results.
The glassEffectID modifier enables glass views to smoothly morph into one another during state changes, creating fluid transitions that feel native to iOS 26.