SwiftUI View Refactor

Attribution: Sourced from steipete/agent-scripts by Peter Steinberger. Originally created by @Dimillian from Dimillian/Skills (2025-12-31).

When to Use

• Refactoring SwiftUI views for consistent layout ordering and structure
• Reviewing dependency injection, Observation, and MV patterns
• Extracting subviews and organizing view model relationships

Overview

Apply a consistent structure and dependency pattern to SwiftUI views, with a focus on ordering, Model-View (MV) patterns, careful view model handling, and correct Observation usage.

Core Guidelines

1) View ordering (top → bottom)

• Environment
• private/public let
• @State / other stored properties
• computed var (non-view)
• init
• body
• computed view builders / other view helpers
• helper / async functions

2) Prefer MV (Model-View) patterns

• Default to MV: Views are lightweight state expressions; models/services own business logic.
• Favor @State, @Environment, @Query, and task/onChange for orchestration.
• Inject services and shared models via @Environment; keep views small and composable.
• Split large views into subviews rather than introducing a view model.

3) Split large bodies and view properties

• If body grows beyond a screen or has multiple logical sections, split it into smaller subviews.
• Extract large computed view properties into dedicated View types when they carry state or complex branching.
• Prefer passing small inputs (data, bindings, callbacks) over reusing the entire parent view state.

// ✅ Extracted sections
var body: some View {
    VStack(alignment: .leading, spacing: 16) {
        HeaderSection(title: title, isPinned: isPinned)
        DetailsSection(details: details)
        ActionsSection(onSave: onSave, onCancel: onCancel)
    }
}

4) View model handling (only if already present)

• Do not introduce a view model unless the request or existing code clearly calls for one.
• If a view model exists, make it non-optional when possible.
• Pass dependencies to the view via init, then pass them into the view model in the view's init.

// ✅ Observation-based view model
@State private var viewModel: SomeViewModel

init(dependency: Dependency) {
    _viewModel = State(initialValue: SomeViewModel(dependency: dependency))
}

5) Observation usage

• For @Observable reference types, store them as @State in the root view.
• Pass observables down explicitly as needed; avoid optional state unless required.

Workflow

1. Reorder the view to match the ordering rules.
2. Favor MV: move lightweight orchestration into the view using @State, @Environment, @Query, task, and onChange.
3. If a view model exists, replace optional view models with a non-optional @State view model initialized in init.
4. Confirm Observation usage: @State for root @Observable view models, no redundant wrappers.
5. Keep behavior intact: do not change layout or business logic unless requested.

Notes

• Prefer small, explicit helpers over large conditional blocks.
• Keep computed view builders below body and non-view computed vars above init.