nucleus-apple-mcp: Skill for Codex

SwiftUI View Refactor

Overview

Refactor SwiftUI views toward small, explicit, stable view types. Default to vanilla SwiftUI: local state in the view, shared dependencies in the environment, business logic in services/models, and view models only when the request or existing code clearly requires one.

Core Guidelines

1) View ordering (top → bottom)

• Enforce this ordering unless the existing file has a stronger local convention you must preserve.
• Environment
• private/public let
• @State / other stored properties
• computed var (non-view)
• init
• body
• computed view builders / other view helpers
• helper / async functions

2) Default to MV, not MVVM

• Views should be lightweight state expressions and orchestration points, not containers for business logic.
• Favor @State, @Environment, @Query, .task, .task(id:), and onChange before reaching for a view model.
• Inject services and shared models via @Environment; keep domain logic in services/models, not in the view body.
• Do not introduce a view model just to mirror local view state or wrap environment dependencies.
• If a screen is getting large, split the UI into subviews before inventing a new view model layer.

3) Strongly prefer dedicated subview types over computed some View helpers

• Flag body properties that are longer than roughly one screen or contain multiple logical sections.
• Prefer extracting dedicated View types for non-trivial sections, especially when they have state, async work, branching, or deserve their own preview.
• Keep computed some View helpers rare and small. Do not build an entire screen out of private var header: some View-style fragments.
• Pass small, explicit inputs (data, bindings, callbacks) into extracted subviews instead of handing down the entire parent state.
• If an extracted subview becomes reusable or independently meaningful, move it to its own file.

Prefer:

var body: some View {
    List {
        HeaderSection(title: title, subtitle: subtitle)
        FilterSection(
            filterOptions: filterOptions,
            selectedFilter: $selectedFilter
        )
        ResultsSection(items: filteredItems)
        FooterSection()
    }
}

private struct HeaderSection: View {
    let title: String
    let subtitle: String

    var body: some View {
        VStack(alignment: .leading, spacing: 6) {
            Text(title).font(.title2)
            Text(subtitle).font(.subheadline)
        }
    }
}

private struct FilterSection: View {
    let filterOptions: [FilterOption]
    @Binding var selectedFilter: FilterOption

    var body: some View {
        ScrollView(.horizontal, showsIndicators: false) {
            HStack {
                ForEach(filterOptions, id: \.self) { option in
                    FilterChip(option: option, isSelected: option == selectedFilter)
                        .onTapGesture { selectedFilter = option }
                }
            }
        }
    }
}