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When working with SwiftUI, we constantly compose views from other views.

A Text view can be placed inside a VStack, a VStack can be embedded in a NavigationStack, and an entire screen can become a child of another view. This ability to build complex user interfaces from smaller building blocks is one of the core ideas behind SwiftUI.

Enums are one of the most useful modeling tools in Swift. We use them for screen states, navigation routes, user actions, errors, commands, feature flags, and many other parts of iOS applications.

A lot of these models have something in common: they describe a closed set of possible values. A screen can be loading, loaded, or failed. A route can open a list, details, or settings. An action can represent view appearance, refresh, or item selection. These concepts map naturally to enums.

By default, SwiftUI's Text view renders formatted measurements as a uniform string and applies the same font and style to both the value and the unit. In some situations we might want to style the unit differently from the value to make it less dominant, for example. We can do this using the AttributedString API.

We can build a reusable Text initializer that targets only the unit component of a formatted measurement and applies a distinct font.

iOS 18 introduced interactive controls that live directly in Control Center and on the Lock Screen. Unlike widgets that only display information, control widgets respond to taps, letting users trigger actions without opening the app. A ControlWidgetToggle is the simplest form: it represents a boolean state and fires an AppIntent when the user taps it.

This article walks through building a Focus Session toggle. Tapping it starts or ends a focus block, and the control reflects the current state each time the user opens Control Center.

Swift Charts is not rendering the gradient incorrectly. It is resolving the gradient in a different coordinate space than you probably expected.

The practical fix is alignsMarkStylesWithPlotArea(_:).

The Animation type in SwiftUI describes the timing curve for a value change, controlling how quickly a value moves toward its destination and whether it overshoots before settling. We can apply it to a specific view using the animation(_:value:) modifier, or wrap a state change in withAnimation(::) to animate all affected views at once.

A blurry video stream is not fixed by simply adding a sharper filter.

Real on-device video quality enhancement has a harder constraint: every decoded frame must be enhanced before the next frame arrives. At 60 fps, the system has about 16 ms per frame for decoding, enhancement, rendering, UI work, and synchronization. If the app copies each frame into CPU memory, converts formats, runs a model, then copies it back to the GPU, the feature may look good in a demo and still fail in production.

The important idea is this: on-device video enhancement is a frame pipeline problem first, and an AI model problem second.

Unfortunately, within Apple’s persistence framework ecosystem, this experience is mainly reflected in SwiftData. The large and stable Core Data ecosystem, which still powers many complex applications, has not received the same level of native integration. To bring the convenience of modern Swift features to this long-standing persistence framework, I recently explored and implemented Observation support in Core Data Evolution(CDE), giving NSManagedObject property-level precise observation capabilities.

This article discusses the motivation behind this feature, how to use it, its implementation approach, the engineering challenges involved, and some of the trade-offs made during development.