Modern SwiftUI (iOS 16+) Expert Skill

Trigger On

• The user asks to write, debug, refactor, or review SwiftUI code.
• The target project version is iOS 16 or higher (utilizing features like NavigationStack, Grid, etc.).
• Development involves state management (@State, @Observable), custom layouts, or animations.

Workflow

1. Perceive (Version and Environment Awareness):

• Confirm if the deployment target is iOS 16+.
• Identify the current state management paradigm (traditional ObservableObject vs. modern @Observable).
• Assess the usage of navigation components (check if deprecated NavigationView is still in use).

1. Reason (Planning Phase):

• Plan the view hierarchy to maximize reusability and minimize redundant body computations.
• Enforce the use of NavigationStack or NavigationSplitView for navigation needs.
• Select the correct data flow tools based on data lifecycle (State, Binding, Environment).

1. Act (Execution Phase):

• Follow SwiftUI core principles to write concise, declarative Swift code.
• Use Grid, ViewThatFits, or custom Layout protocols to implement complex layouts.
• Leverage modern modifiers (e.g., .sheet with detents).

1. Validate (Standard Validation):

• Check for "God Views" (views with excessive logic or body content) and suggest splitting them.
• Ensure @State and @Binding are used correctly to avoid unnecessary view refreshes.
• Verify that the UI remains fluid and adheres to Apple's Human Interface Guidelines (HIG).

Feature Roadmap (SwiftUI Evolution)

iOS 13.0 - 15.0 (Foundation Era)

• Declarative Syntax: Core View protocol and body property.
• State Management: @State, @Binding, @ObservedObject, @EnvironmentObject.
• Basic Containers: VStack, HStack, ZStack, List.
• Legacy Navigation: NavigationView and NavigationLink.

iOS 16.0 - 17.0 (Modern Era)

• NavigationStack: Decoupled and data-driven navigation pattern.
• Observation Framework: @Observable macro (Swift 5.9+) replacing ObservableObject.
• Advanced Layouts: Grid, ViewThatFits, and Layout protocol.
• Swift Charts: Native data visualization framework.

iOS 18.0+ (Latest Features)

• SwiftUI Animations: New phase-based and keyframe-based animation APIs.
• Interaction Enhancements: Improved Scroll View controls and gesture handling.

Coding Standards

• Declarative Style: Keep the view tree structure clear and avoid writing complex logic within body.
• Modularity: Split subviews into independent structs instead of computed properties.
• Preview Guidelines: Use the #Preview macro for rapid development, testing across multiple environment settings (Dark Mode, different locales).
• Type Safety: Prefer strongly typed navigation paths and environment keys.

Deliver

• Version-Optimized Code: Provide code utilizing iOS 16+ features (e.g., NavigationStack, presentationDetents).
• Modular View Components: Deconstruct large views into single-responsibility, reusable components.
• Modern State Management: Prioritize the @Observable pattern for projects supporting Swift 5.9+.

Validate

• Ensure code compiles without warnings and uses the best available APIs for the target version.
• Validate view body execution efficiency, ensuring no side effects are included.
• Confirm that data flow follows the unidirectional flow principle whenever possible.

Documentation

Official References

• SwiftUI Documentation
• Human Interface Guidelines (Layout)

Internal References

• SwiftUI Coding Style and Naming Conventions
• SwiftUI Anti-Patterns and Best Practices
• Modern SwiftUI Patterns Guide