Alignment guides are a powerful but often underused part of SwiftUI's layout system. They let us describe relationships between views using meaningful points in their content, without frame measurements or fixed offsets. I wrote a post explaining them in detail: nilcoalescing.com/blog/Alignme...

Alignment guides in SwiftUI

Learn how alignment guides position views in SwiftUI, how to override a built-in guide, and how to define a custom alignment for views in nested containers.

nilcoalescing.com

When SwiftUI updates a wrapped UIKit view, we need to know whether that view produced the updated value. Custom transaction values can help us here. nilcoalescing.com/blog/Trackin... #SwiftUI #iOSDev #UIKit

Tracking value sources to prevent recursive SwiftUI updates

Use SwiftUI transaction values to identify updates made by wrapped UITextView and NSTextView editors, preventing the same values from being applied again when SwiftUI sends them back.

nilcoalescing.com

📱 𝐵𝑢𝑖𝑙𝑑𝑖𝑛𝑔 𝐴𝑑𝑎𝑝𝑡𝑖𝑣𝑒 𝑁𝑜𝑛-𝑀𝑜𝑑𝑎𝑙 𝑃𝑎𝑛𝑒𝑙𝑠 𝑖𝑛 𝑆𝑤𝑖𝑓𝑡𝑈𝐼 by Matthaus Woolard (@hishnash.bsky.social) With the new resizability requirements in iOS 27, the old sheet APIs just don't cut it for landscape on iPhone. #iOSDev #SwiftUI nilcoalescing.com/blog/Buildin...

Building adaptive non-modal panels in SwiftUI

Learn how to build a non-modal, detent-based sheet API in SwiftUI that adapts from a bottom panel in portrait to an edge-aligned panel in landscape.

nilcoalescing.com

The July issue of the Nil Coalescing newsletter is out! It includes our trip to the /dev/world on tour conference, The SwiftUI Way book update, and a catalog of our recent Swift and SwiftUI blog posts. You can read it online: nilcoalescing.com/newsletter/2...

Nil Coalescing - Nil Coalescing Newsletter – July 2026

We've been putting this year's WWDC announcements into practice and preparing our apps for iOS 27 after a busy start to July at /dev/world on tour in Sydney. I've also released a substantial update to...

nilcoalescing.com

To keep pan, zoom and rotation responsive in @exstoapp.bsky.social, we reproject the latest GPU result while Metal renders an updated canvas. I wrote about the process: nilcoalescing.com/blog/Keeping... #iOSDev #Metal

Keeping canvas interactions responsive with frame reprojection

Keep a complex Metal-rendered canvas responsive during pan, zoom and rotation gestures by reprojecting rendered states with CAMetalLayer.

nilcoalescing.com

Configure a SwiftUI app to schedule and handle a background fetch task using the Background Tasks framework and the backgroundTask(_:action:) SwiftUI modifier: nilcoalescing.com/blog/Schedul... #iOSDev #SwiftUI

Scheduling and handling background app refresh in SwiftUI

Configure a SwiftUI app to schedule and handle a background fetch task using the Background Tasks framework and the backgroundTask(_:action:) SwiftUI modifier.

nilcoalescing.com

I’ve been wanting to explore and document SwiftUI’s blend modes for a while. I finally worked through all 21 of them, with visuals and practical examples showing how each one works and when it can be useful: nilcoalescing.com/blog/BlendMo... #iOSDev #SwiftUI

Blend modes in SwiftUI

Explore every SwiftUI blend mode through focused visuals and practical use cases, and learn how to control which views participate in each operation.

nilcoalescing.com

Really looking forward to iOSDevUK this September! It’ll be my first talk at an iOS conference. See you in Aberystwyth 🎤 #iOSDevUK #iOSDev #Swift

Learn how to build a non-modal, detent-based sheet API in SwiftUI that adapts from a bottom panel in portrait to an edge-aligned panel in landscape: nilcoalescing.com/blog/Buildin... #iOSDev #SwiftUI

Building adaptive non-modal panels in SwiftUI

Learn how to build a non-modal, detent-based sheet API in SwiftUI that adapts from a bottom panel in portrait to an edge-aligned panel in landscape.

nilcoalescing.com

Learn how SwiftUI's similarly named geometryGroup(), compositingGroup() and drawingGroup() modifiers affect distinct stages of animation and rendering, and when each is appropriate: nilcoalescing.com/blog/Geometr... #iOSDev #SwiftUI

Geometry, compositing and drawing groups in SwiftUI

Learn how SwiftUI's similarly named geometryGroup(), compositingGroup() and drawingGroup() modifiers affect distinct stages of animation and rendering, and when each is appropriate.

nilcoalescing.com

To prepare Strolly for app resizability in iOS 27, we wanted its non-modal detent sheets to adapt into side panels on wider displays. SwiftUI sheets don’t support that presentation, so we built our own panel API: nilcoalescing.com/blog/Buildin... #SwiftUI #iOSDev

Building adaptive non-modal panels in SwiftUI

Learn how to build a non-modal, detent-based sheet API in SwiftUI that adapts from a bottom panel in portrait to an edge-aligned panel in landscape.

nilcoalescing.com

Strolly (@strollyapp.bsky.social) got an update! You can now indicate the areas you prefer to walk in and the areas you'd like to avoid, and future generated walks will take your preferences into account. Thank you @hishnash.bsky.social for working on it! apps.apple.com/us/app/strol... #IndieDev

SwiftUI has three similarly named grouping modifiers: geometryGroup(), compositingGroup() and drawingGroup(). If, like me, you sometimes forget which one does what, I’ve just published a guide explaining how they differ and when to use each one: nilcoalescing.com/blog/Geometr... #iOSDev #SwiftUI

Geometry, compositing and drawing groups in SwiftUI

Learn how SwiftUI's similarly named geometryGroup(), compositingGroup() and drawingGroup() modifiers affect distinct stages of animation and rendering, and when each is appropriate.

nilcoalescing.com

Strolly 1.6 is here! Show Strolly the areas you enjoy and the places you would rather avoid, helping it find better walks for you. New Home and Lock Screen widgets keep today’s route close at hand. Get it on the App Store: apps.apple.com/app/apple-st... #Walking #IndieDev

One of my favorite features in Tintly is the ability to easily reorganize colors for quick experimentation when designing a gradient. In v1.1, it's also possible to select multiple points on the canvas and swap or shuffle their colors for a more controlled change: apps.apple.com/us/app/tintl...

I've released an update to my book "The SwiftUI Way"! It expands the coverage of SwiftUI data flow, view updates, and performance, and includes new guidance for changes introduced in Xcode 27: books.nilcoalescing.com/the-swiftui-... #iOSDev #SwiftUI

The SwiftUI Way

A field guide to SwiftUI patterns and anti-patterns

books.nilcoalescing.com

Tintly 1.1 is now out 🎉 This update brings improved CSS and SVG export, a resizable export window, multiple color selection and shuffling, and redesigned palette import and saved gradients windows. The new version is available on the Mac App Store: apps.apple.com/us/app/tintl... #IndieDev #macOS

When storing custom values in properties of an @Observable, it’s recommended to make them Equatable to minimize SwiftUI view updates. I’ve just published a post looking at how @Observable handles equal assignments and why Equatable conformance matters: nilcoalescing.com/blog/Equatab...

Equatable properties in @Observable classes

Prevent unnecessary SwiftUI view updates by making custom types stored in @Observable properties conform to Equatable.

nilcoalescing.com

Just submitted a new version of Tintly: Mesh Gradient Editor to the App Store! It includes a redesigned resizable export window for easier previewing of generated code, improved SVG and CSS export, and a few other improvements based on user feedback. Hopefully it'll be out soon!

In Xcode 27, the @Entry macro shows a new warning when we assign an unstable default, such as a newly created class instance, to a custom SwiftUI environment value. I wrote about why this can cause unnecessary view updates and how to fix it: nilcoalescing.com/blog/Unstabl... #iOSDev #SwiftUI

The hidden cost of unstable SwiftUI environment defaults

Learn why Xcode 27 shows a warning when an @Entry declaration creates a new class instance for every fallback access, how unstable environment defaults can cause unnecessary SwiftUI view updates, and ...

nilcoalescing.com

The Nil Coalescing website now provides a way to create a custom book bundle from my Swift and SwiftUI books: books.nilcoalescing.com/bundles/custom You can pick any combination of books and save $5 per book when getting more than one at the same time!

Nil Coalescing Books - Build your own bundle

Build a custom book bundle from Nil Coalescing

books.nilcoalescing.com

Custom SwiftUI bindings are often created with Binding(get:set:), but closure-based bindings can have subtle performance implications. In my new post, I look at an alternative approach using labeled subscripts: nilcoalescing.com/blog/CustomB... #SwiftUI #iOSDev

Custom bindings in SwiftUI: closures vs subscripts

Learn how closure-based bindings can affect SwiftUI view updates, and how labeled subscripts give the framework a more stable way to track changes.

nilcoalescing.com

The June issue of the Nil Coalescing newsletter is out! I've shared my upcoming conference plans, my latest articles covering SwiftUI in iOS 27, an introduction to Tintly, my new macOS app for designing mesh gradients, and other app updates. nilcoalescing.com/newsletter/2...

Nil Coalescing - Nil Coalescing Newsletter – June 2026

I hope you enjoyed WWDC26, whether you were attending in person or following along online. The most exciting update this year has definitely been the new and improved Siri, but we've also got a lot of...

nilcoalescing.com

Looking for a quick and easy way to design mesh gradients? Try Tintly, a new macOS tool for creating mesh gradients visually and exporting them in different formats, including SwiftUI code: apps.apple.com/us/app/tintl...

I'm really looking forward to speaking at /dev/world on tour next week! I'll be sharing some of my favorite SwiftUI improvements in iOS 27. Excited to catch up with friends, meet new people, and spend a few days in Sydney! ontour.devworld.au

AsyncImage got some useful improvements in iOS 27. We can now pass a URLRequest for per-image headers, caching, and timeout control, and provide a custom URLSession for image loading across a SwiftUI view hierarchy. You can learn more in my new post: nilcoalescing.com/blog/AsyncIm...

AsyncImage improvements in iOS 27

iOS 27 gives AsyncImage more control over remote image loading with URLRequest support for custom headers, cache policies, and timeouts, plus the ability to provide a custom URLSession across a SwiftU...

nilcoalescing.com

The Cold & Iced section in Breve has been growing! Four new recipes landed today, ready for hot days and slow, refreshing coffee breaks. Find them in Breve: apps.apple.com/us/app/breve... #Coffee #CoffeeRecipes #iOS

Reorder items within and between custom SwiftUI containers, and build selection-aware multi-item drag and drop interactions with the new APIs in iOS 27: nilcoalescing.com/blog/NewSwif...

New SwiftUI APIs for reordering and drag and drop on iOS 27

Reorder items within and between custom SwiftUI containers, and build selection-aware multi-item drag and drop interactions with the new APIs in iOS 27.

nilcoalescing.com

Excited to share that I'll be running a SwiftUI workshop at iOSDevUK this September! Really looking forward to attending the conference, meeting everyone, and spending some time in Aberystwyth. Hope to see you there!

I've been experimenting with the new SwiftUI APIs for reordering items in container views and drag-and-drop in iOS 27. I documented what I've learned in my new blog post: nilcoalescing.com/blog/NewSwif...

New SwiftUI APIs for reordering and drag and drop on iOS 27

Reorder items within and between custom SwiftUI containers, and build selection-aware multi-item drag and drop interactions with the new APIs in iOS 27.

nilcoalescing.com