Swift Data

What it does

This skill provides a comprehensive guide to using SwiftData for building frontend user interfaces and experiences within a modular MVVM-C architecture. It focuses on best practices for data modeling, persistence, synchronization, and error handling specifically when working with the "clinic" modular approach. The skill ensures that SwiftData types are isolated to Data layer implementations, promoting clean separation of concerns between feature modules, domain logic, and data access.

When to use it

• When defining @Model entity classes and mapping them to corresponding domain structs.
• When setting up the ModelContainer and ModelContext within your application's Data layer.
• When implementing repository protocols using SwiftData as the underlying persistence mechanism.
• When designing stale-while-revalidate data fetching strategies.

Key capabilities

• Provides guidance on defining @Model entities and mapping them to domain structs.
• Covers setup of ModelContainer and ModelContext.
• Explains how to implement repository protocols using SwiftData.
• Details best practices for stale-while-revalidate data fetching.
• Enforces a strict architectural separation: Feature modules import only Domain and DesignSystem, while Data owns SwiftData implementation.

Example prompts

• "How should I structure my @Model entities to align with the clinic architecture?"
• "Can you explain how to implement repository protocols using SwiftData in this skill's recommended approach?"
• "What are the best practices for setting up ModelContext within a Data layer following these guidelines?"

Tips & gotchas

• This skill assumes familiarity with the clinic modular MVVM-C architecture. Ensure your project is structured accordingly before applying its guidance.
• SwiftData types (@Model, ModelContext, @Query) are strictly confined to Data layer implementations; avoid importing them into Feature or Domain modules.
• The skill emphasizes a direct ViewModel call to repository protocols, bypassing default use-case/interactor layers.