swiftui-patterns

Use the @Observable macro on a final class to track property-level changes, then hold it in the view with @State. SwiftUI only re-renders views that read the changed property, replacing the older ObservableObject and @Published pattern.

@State owns view-local value types, @Binding creates a two-way reference to a parent's @State, and @Bindable creates two-way bindings to properties of an @Observable class. Choose the simplest wrapper that fits the data flow.

Create a Hashable enum of destinations and an @Observable Router holding a NavigationPath. Bind the path to NavigationStack and map destinations to views using navigationDestination(for:) for programmatic, type-safe routing.

Use @Observable in new code because it tracks property-level changes and avoids unnecessary re-renders. ObservableObject, @Published, @StateObject, and @EnvironmentObject are considered legacy patterns to migrate away from.

Slow scrolling usually comes from eager containers, unstable ForEach identifiers, or expensive modifiers like shadow, blur, and mask triggering offscreen rendering. Use LazyVStack, stable unique IDs, and Equatable conformance on expensive views.

Never perform I/O, network calls, or heavy computation inside body or init. Use the .task modifier for async work since it cancels automatically when the view disappears, or call explicit load methods on the view model.