fosmvvm-swiftui-view-generator

name	fosmvvm-swiftui-view-generator
description	Generate SwiftUI views that render FOSMVVM ViewModels. Scaffolds ViewModelView pattern with binding, loading states, and previews.
homepage	https://github.com/foscomputerservices/FOSUtilities
metadata	{"clawdbot":{"emoji":"📱","os":["darwin"]}}

FOSMVVM SwiftUI View Generator

Generate SwiftUI views that render FOSMVVM ViewModels.

Conceptual Foundation

For full architecture context, see FOSMVVMArchitecture.md | OpenClaw reference

API catalog: check ../shared/api-catalog/FOSMVVM.md § SwiftUI Support before hand-writing helpers.

In FOSMVVM, Views are thin rendering layers that display ViewModels:

┌─────────────────────────────────────────────────────────────┐
│                    ViewModelView Pattern                     │
├─────────────────────────────────────────────────────────────┤
│                                                              │
│  ViewModel (Data)          ViewModelView (SwiftUI)          │
│  ┌──────────────────┐     ┌──────────────────┐             │
│  │ title: String    │────►│ Text(vm.title)   │             │
│  │ items: [Item]    │────►│ ForEach(vm.items)│             │
│  │ isEnabled: Bool  │────►│ .disabled(!...)  │             │
│  └──────────────────┘     └──────────────────┘             │
│                                                              │
│  Operations (Actions)                                        │
│  ┌──────────────────┐     ┌──────────────────┐             │
│  │ submit()         │◄────│ Button(action:)  │             │
│  │ cancel()         │◄────│ .onAppear { }    │             │
│  └──────────────────┘     └──────────────────┘             │
│                                                              │
└─────────────────────────────────────────────────────────────┘

Key principle: Views don't transform or compute data. They render what the ViewModel provides.

---

View-ViewModel Alignment

The View filename should match the ViewModel it renders.

Sources/
  {ViewModelsTarget}/
    {Feature}/
      {Feature}ViewModel.swift        ←──┐
      {Entity}CardViewModel.swift     ←──┼── Same names
                                          │
  {ViewsTarget}/                          │
    {Feature}/                            │
      {Feature}View.swift             ────┤  (renders {Feature}ViewModel)
      {Entity}CardView.swift          ────┘  (renders {Entity}CardViewModel)

This alignment provides:

• Discoverability - Find the view for any ViewModel instantly
• Consistency - Same naming discipline across the codebase
• Maintainability - Changes to ViewModel are reflected in view location

---

Core Components

1. ViewModelView Protocol

Every view conforms to ViewModelView:

public struct MyView: ViewModelView {
    private let viewModel: MyViewModel

    public var body: some View {
        Text(viewModel.title)
    }

    public init(viewModel: MyViewModel) {
        self.viewModel = viewModel
    }
}

Required:

• private let viewModel: {ViewModel}
• public init(viewModel:)
• Conforms to ViewModelView protocol

2. Operations (Optional)

Display-only views skip this entire section. A View whose ViewModel has no operations property is display-only by definition — no Operations files exist on either side of the seam, no repaintToggle, no testDataTransporter. Do not invent an empty Operations protocol for symmetry; absence of operations is the signal that the View is display-only. (See "View Categories" below for the full distinction.)

Operations are an architectural seam

An Operations protocol is the framework-side analog of ServerRequest: a contract the View calls into without knowing who satisfies it. Three files participate, on two sides of the seam:

File	Side	Purpose
<Name>Operations.swift	Framework (shared module)	The protocol — what actions the View can dispatch
<Name>StubOps.swift	Framework (shared module)	Stub implementation — used in previews and LocalizableTestCase-driven tests
<Name>Ops.swift	App target (implementation side)	Live implementation — orchestrates services, writes to storage, dispatches ServerRequests

For a feature LandingPage, these live at:

• Sources/ViewModels/Operations/LandingPage/LandingPageOperations.swift
• Sources/ViewModels/Operations/LandingPage/LandingPageStubOps.swift
• Sources/{AppTarget}/Operations/LandingPage/LandingPageOps.swift

The View imports only the framework side and is unaware of which implementation runs. App Intents, lock-screen transport actions, and other non-View entry points dispatch through the same Operations protocol — the View is one entry point of several, not the owner of the action vocabulary.

Two protocol layers to keep distinct:

• FOSMVVM.ViewModelOperations — the framework's base protocol. Every per-feature operations protocol conforms to it.
• <Name>ViewModelOperations (e.g., LandingPageViewModelOperations) — your project's per-feature protocol; conforms to FOSMVVM.ViewModelOperations and lists the actions the View dispatches.

Generic over any at op method signatures

Per the architecture rule (no existentials at architectural boundaries), Operations method signatures take Fields conformers as generic parameters, not any:

// ✅ GOOD — generic specialization preserves the concrete type for the live op.
protocol ConversationOperations: ViewModelOperations {
    func create<F: ConversationFields>(from fields: F) async throws
}

// ❌ BAD — `any` erases the concrete type and pulls existentials through the call graph.
protocol ConversationOperations: ViewModelOperations {
    func create(from fields: any ConversationFields) async throws
}

Storage is a separate decision from method signatures. The View's operations property is typed as any <Name>ViewModelOperations — that's required, since Apple's API forces a concrete View struct shape and the View has to store the value somehow. This is the exception arch.md §1.5 explicitly carves out for "structural requirements that leave no alternative."

Crucially, any at storage does not infect the protocol's method signatures. Swift 5.7+ opens the existential implicitly at each call site, so a generic method called on an any P value still specializes to a concrete type at the call site:

private let operations: any ConversationOperations          // ← `any` at storage is fine

private func submit() async throws {
    try await operations.create(from: fields)              // ← F inferred concretely
}

The rule to internalize: any is acceptable at single-value storage sites; generics are required at protocol method signatures. The architecture's anti-existential pressure is about preventing erasure from compounding through the call graph — and a stored any P does not compound, because each method call re-specializes.

Server-backed example

Interactive views have operations:

public struct MyView: ViewModelView {
    private let viewModel: MyViewModel
    private let operations: any MyViewModelOperations

    #if DEBUG
    @State private var repaintToggle = false
    #endif

    public var body: some View {
        Button(action: performAction) {
            Text(viewModel.buttonLabel)
        }
        #if DEBUG
        .testDataTransporter(viewModelOps: operations, repaintToggle: $repaintToggle)
        #endif
    }

    public init(viewModel: MyViewModel) {
        self.viewModel = viewModel
        self.operations = viewModel.operations
    }

    private func performAction() {
        operations.performAction()
        toggleRepaint()
    }

    private func toggleRepaint() {
        #if DEBUG
        repaintToggle.toggle()
        #endif
    }
}

When views have operations:

• Store operations from viewModel.operations in init
• Add @State private var repaintToggle = false (DEBUG only)
• Add .testDataTransporter(viewModelOps:repaintToggle:) modifier (DEBUG only)
• Call toggleRepaint() after every operation invocation

Why toggleRepaint() exists. Client-hosted ops mutate @Observable storage that test harnesses (and occasionally SwiftUI itself) don't always re-observe in time for the next assertion. Toggling a @State flag forces a deterministic re-render at the View boundary, so UI tests see the post-op state instead of the pre-op state. In production builds the toggle is compiled out — it costs nothing at runtime.

Async vs sync op shape. Server-backed ops are typically async (try await operations.performAction()) and pair with Button(errorBinding:asyncAction:) / .task(errorBinding:) / .onAsyncSubmit. Client-hosted scalar-mutation ops are typically sync — the live op writes a property on @Observable storage and returns. Don't add async to an op method that doesn't need it; don't omit async on one that calls a ServerRequest.

The example above shows a server-backed op — operations.performAction() dispatches a ServerRequest. For client-hosted ops (those that mutate local @Observable storage), the call site shape is different — the View must inject storage from the environment and hand it to the op explicitly. See below.

2a. Client-Hosted Operations: @Environment Injection and output: at the Call Site

Applies when the ViewModel is client-hosted and its operations mutate one or more @Observable storage objects (e.g., UserSettings, DeviceState). Server-backed operations use the plain pattern shown in section 2.

Client-hosted ops take their write target as a trailing output storage: parameter. The ViewModel does not hold a reference to storage (see Architecture Patterns → VMs Hold Scalars); the View reads storage from @Environment and hands the reference to the op at the call site.

public struct PreferencesView: ViewModelView {
    // The reference to the @Observable lives on the View, not the ViewModel.
    @Environment(UserSettings.self) private var settings

    private let viewModel: PreferencesViewModel
    // Stored as `any` — required at View storage, see §2 "Generic over `any`".
    // The protocol's *method signatures* remain generic; existential opening
    // re-specializes at each call site.
    private let operations: any PreferencesViewModelOperations

    #if DEBUG
    @State private var repaintToggle = false
    #endif

    public var body: some View {
        VStack {
            Toggle(
                viewModel.notificationsLabel,
                isOn: Binding(
                    get: { viewModel.notificationsEnabled },
                    set: { setNotifications($0) }
                )
            )
            Picker(viewModel.themeLabel, selection: Binding(
                get: { viewModel.theme },
                set: { setTheme($0) }
            )) {
                // ... options
            }
        }
        #if DEBUG
        .testDataTransporter(viewModelOps: operations, repaintToggle: $repaintToggle)
        #endif
    }

    public init(viewModel: PreferencesViewModel) {
        self.viewModel = viewModel
        self.operations = viewModel.operations
    }

    private func setNotifications(_ enabled: Bool) {
        // Hand the reference from @Environment to the op at the call site.
        operations.setNotificationsEnabled(enabled, output: settings)
        toggleRepaint()
    }

    private func setTheme(_ theme: Theme) {
        operations.setTheme(theme, output: settings)
        toggleRepaint()
    }

    private func toggleRepaint() {
        #if DEBUG
        repaintToggle.toggle()
        #endif
    }
}

The mental model:

• @Environment(UserSettings.self) puts the reference on the View.
• The VM has scalars only (viewModel.notificationsEnabled: Bool, viewModel.theme: Theme), projected from settings by the parent's .bind(appState: .init(...)) call. The VM never holds the UserSettings reference.
• The mutation closure reads settings from its own @Environment and passes it to the op as output: settings. The reference never crosses the VM boundary.

Common mistakes to avoid:

Anti-pattern	Why it's wrong
@State private var settings = UserSettings() on the view	View should read storage from @Environment, not own it
viewModel.settings = ...	VMs never hold @Observable references (rule 4 of Forward Projection)
operations.setTheme(.dark) (no output:)	Mutation has no target — the op can't write anywhere
operations.setTheme(.dark, in: settings)	in reads like input; output is the correct label (conflation anti-pattern)
Reading settings.theme in this View's body for display	Display reads belong on the VM scalar (viewModel.theme); env reads break projection

Full rationale — why the VM holds scalars, why the reference flows through the call site rather than the VM, what breaks otherwise — lives in Architecture Patterns → Ops Conventions and Architecture Patterns → The Four Rules of Forward Projection.

3. Child View Binding

Parent views bind child views using .bind(appState:):

public struct ParentView: ViewModelView {
    @Environment(AppState.self) private var appState
    private let viewModel: ParentViewModel

    public var body: some View {
        VStack {
            Text(viewModel.title)

            // Bind child view with subset of parent's data
            ChildView.bind(
                appState: .init(
                    itemId: viewModel.selectedId,
                    isConnected: viewModel.isConnected
                )
            )
        }
    }
}

The .bind() pattern:

• Child views use .bind(appState:) to receive data from parent
• Parent creates child's AppState from its own ViewModel data
• Enables composition without tight coupling

4. Form Views with Validation

Forms use FormFieldView and Validations environment:

public struct MyFormView: ViewModelView {
    @Environment(Validations.self) private var validations
    @Environment(\.focusState) private var focusField
    @State private var error: Error?

    private let viewModel: MyFormViewModel
    private let operations: any MyFormViewModelOperations

    public var body: some View {
        Form {
            FormFieldView(
                fieldModel: viewModel.$email,
                focusField: focusField,
                fieldValidator: viewModel.validateEmail,
                validations: validations
            )

            Button(errorBinding: $error, asyncAction: submit) {
                Text(viewModel.submitButtonLabel)
            }
            .disabled(validations.hasError)
        }
        .onAsyncSubmit {
            await submit()
        }
        .alert(
            errorBinding: $error,
            title: viewModel.errorTitle,
            message: viewModel.errorMessage,
            dismissButtonLabel: viewModel.dismissButtonLabel
        )
    }
}

Form patterns:

• @Environment(Validations.self) for validation state
• FormFieldView for each input field
• Button(errorBinding:asyncAction:) for async actions
• .disabled(validations.hasError) on submit button
• Separate handling for validation errors vs general errors

5. Previews

Use .previewHost() for SwiftUI previews:

#if DEBUG
#Preview {
    MyView.previewHost(
        bundle: MyAppResourceAccess.localizationBundle
    )
    .environment(AppState())
}

#Preview("With Data") {
    MyView.previewHost(
        bundle: MyAppResourceAccess.localizationBundle,
        viewModel: .stub(title: "Preview Title")
    )
    .environment(AppState())
}
#endif

View Categories

The first decision when generating a View is interactive vs. display-only — and that decision is forced by the ViewModel, not chosen by the View author.

ViewModel has operations property?	View kind	Operations files
No	Display-only	None — do not create empty Operations protocol/Stub/Live files
Yes	Interactive (server-backed or client-hosted)	<Name>Operations.swift + <Name>StubOps.swift (framework side) + <Name>Ops.swift (app side)

Absence of operations is a positive signal that the View originates no actions. Inventing an empty Operations protocol "for symmetry" is an anti-pattern (arch.md §3.4).

Display-Only Views

Views that just render data (no user interactions):

public struct InfoView: ViewModelView {
    private let viewModel: InfoViewModel

    public var body: some View {
        VStack {
            Text(viewModel.title)
            Text(viewModel.description)

            if viewModel.isActive {
                Text(viewModel.activeStatusLabel)
            }
        }
    }

    public init(viewModel: InfoViewModel) {
        self.viewModel = viewModel
    }
}

Characteristics:

• No operations property
• No repaintToggle or testDataTransporter
• Just renders ViewModel properties
• May have conditional rendering based on ViewModel state

Interactive Views

Views with user actions:

public struct ActionView: ViewModelView {
    @State private var error: Error?

    private let viewModel: ActionViewModel
    private let operations: any ActionViewModelOperations

    #if DEBUG
    @State private var repaintToggle = false
    #endif

    public var body: some View {
        VStack {
            Button(action: performAction) {
                Text(viewModel.actionLabel)
            }

            Button(role: .cancel, action: cancel) {
                Text(viewModel.cancelLabel)
            }
        }
        .alert(
            errorBinding: $error,
            title: viewModel.errorTitle,
            message: viewModel.errorMessage,
            dismissButtonLabel: viewModel.dismissButtonLabel
        )
        #if DEBUG
        .testDataTransporter(viewModelOps: operations, repaintToggle: $repaintToggle)
        #endif
    }

    public init(viewModel: ActionViewModel) {
        self.viewModel = viewModel
        self.operations = viewModel.operations
    }

    private func performAction() {
        operations.performAction()
        toggleRepaint()
    }

    private func cancel() {
        operations.cancel()
        toggleRepaint()
    }

    private func toggleRepaint() {
        #if DEBUG
        repaintToggle.toggle()
        #endif
    }
}

Form Views

Views with validated input fields:

• Use FormFieldView for each input
• @Environment(Validations.self) for validation state
• Button disabled when validations.hasError
• Separate error handling for validation vs operation errors

Container Views

Views that compose child views:

public struct ContainerView: ViewModelView {
    @Environment(AppState.self) private var appState
    private let viewModel: ContainerViewModel
    private let operations: any ContainerViewModelOperations

    public var body: some View {
        VStack {
            switch viewModel.state {
            case .loading:
                ProgressView()

            case .ready:
                ChildAView.bind(
                    appState: .init(id: viewModel.selectedId)
                )

                ChildBView.bind(
                    appState: .init(
                        isActive: viewModel.isActive,
                        level: viewModel.level
                    )
                )
            }
        }
    }
}

When to Use This Skill

• Creating a new SwiftUI view for a FOSMVVM app
• Building UI to render a ViewModel
• Following an implementation plan that requires new views
• Creating forms with validation
• Building container views that compose child views

What This Skill Generates

File	Location	Purpose
{ViewName}View.swift	Sources/{ViewsTarget}/{Feature}/	The SwiftUI view

Note: The corresponding ViewModel and ViewModelOperations should already exist (use fosmvvm-viewmodel-generator skill).

Project Structure Configuration

Placeholder	Description	Example
{ViewName}	View name (without "View" suffix)	TaskList, SignIn
{ViewsTarget}	SwiftUI views SPM target	MyAppViews
{Feature}	Feature/module grouping	Tasks, Auth

Pattern Implementation

This skill references conversation context to determine view structure:

View Type Detection

From conversation context, the skill identifies:

• ViewModel structure (from prior discussion or specifications read by Claude)
• View category: Display-only, interactive, form, or container
• Operations needed: Whether view has user-initiated actions
• Child composition: Whether view binds child views

Component Selection

Based on view type:

• Display-only: ViewModelView protocol, viewModel property only
• Interactive: Add operations, repaintToggle, testDataTransporter, toggleRepaint()
• Form: Add Validations environment, FormFieldView, validation error handling
• Container: Add child view .bind() calls

Code Generation

Generates view file with:

1. ViewModelView protocol conformance
2. Properties (viewModel, operations if needed, repaintToggle if interactive)
3. Body with rendering logic
4. Init storing viewModel and operations
5. Action methods (if interactive)
6. Test infrastructure (if interactive)
7. Previews for different states

Context Sources

Skill references information from:

• Prior conversation: Requirements discussed with user
• Specification files: If Claude has read specifications into context
• ViewModel definitions: From codebase or discussion

Key Patterns

Error Handling Pattern

@State private var error: Error?

var body: some View {
    VStack {
        Button(errorBinding: $error, asyncAction: submit) {
            Text(viewModel.submitLabel)
        }
    }
    .alert(
        errorBinding: $error,
        title: viewModel.errorTitle,
        message: viewModel.errorMessage,
        dismissButtonLabel: viewModel.dismissButtonLabel
    )
}

private func submit() async {
    do {
        try await operations.submit()
    } catch {
        self.error = error
    }
    toggleRepaint()
}

Validation Error Pattern

For forms, handle validation errors separately:

private func submit() async {
    let validations = validations
    do {
        try await operations.submit(data: viewModel.data)
    } catch let error as MyRequest.ResponseError {
        if !error.validationResults.isEmpty {
            validations.replace(with: error.validationResults)
        } else {
            self.error = error
        }
    } catch {
        self.error = error
    }
    toggleRepaint()
}

Async Task Pattern

var body: some View {
    VStack {
        if isLoading {
            ProgressView()
        } else {
            contentView
        }
    }
    .task(errorBinding: $error) {
        try await loadData()
    }
}

private func loadData() async throws {
    isLoading = true
    try await operations.loadData()
    isLoading = false
    toggleRepaint()
}

Conditional Rendering Pattern

Use ViewModel state for conditionals:

var body: some View {
    VStack {
        if viewModel.isEmpty {
            Text(viewModel.emptyStateMessage)
        } else {
            ForEach(viewModel.items) { item in
                ItemRow(item: item)
            }
        }
    }
}

Computed View Components Pattern

Extract reusable view fragments as computed properties:

private var headerView: some View {
    HStack {
        Text(viewModel.title)
        Spacer()
        Image(systemName: viewModel.iconName)
    }
}

var body: some View {
    VStack {
        headerView
        contentView
    }
}

Result/Error Handling Pattern

When a view needs to render multiple possible ViewModels (success, various error types), use an enum wrapper:

The Wrapper ViewModel:

@ViewModel
public struct TaskResultViewModel {
    public enum Result {
        case success(TaskViewModel)
        case notFound(NotFoundViewModel)
        case validationError(ValidationErrorViewModel)
        case permissionDenied(PermissionDeniedViewModel)
    }

    public let result: Result
    public var vmId: ViewModelId = .init(type: Self.self)

    public init(result: Result) {
        self.result = result
    }
}

The View:

public struct TaskResultView: ViewModelView {
    private let viewModel: TaskResultViewModel

    public var body: some View {
        switch viewModel.result {
        case .success(let vm):
            TaskView(viewModel: vm)
        case .notFound(let vm):
            NotFoundView(viewModel: vm)
        case .validationError(let vm):
            ValidationErrorView(viewModel: vm)
        case .permissionDenied(let vm):
            PermissionDeniedView(viewModel: vm)
        }
    }

    public init(viewModel: TaskResultViewModel) {
        self.viewModel = viewModel
    }
}

Key principles:

• Each error scenario has its own ViewModel type
• The wrapper enum associates specific ViewModels with each case
• The view switches on the enum and renders the appropriate child view
• Maintains type safety (no any ViewModel existentials)
• No generic error handling - each error type is specific and meaningful

ViewModelId Initialization - CRITICAL

IMPORTANT: ViewModelId controls SwiftUI's view identity system via the .id(vmId) modifier. Incorrect initialization causes SwiftUI to treat different data as the same view, breaking updates.

❌ WRONG - Never use this:

public var vmId: ViewModelId = .init()  // NO! Generic identity

✅ MINIMUM - Use type-based identity:

public var vmId: ViewModelId = .init(type: Self.self)

This ensures views of the same type get unique identities.

✅ IDEAL - Use data-based identity when available:

public struct TaskViewModel {
    public let id: ModelIdType
    public var vmId: ViewModelId

    public init(id: ModelIdType, /* other params */) {
        self.id = id
        self.vmId = .init(id: id)  // Ties view identity to data identity
        // ...
    }
}

Why this matters:

• SwiftUI uses .id() modifier to determine when to recreate vs update views
• vmId provides this identity for ViewModelViews
• Wrong identity = views don't update when data changes
• Data-based identity (.init(id:)) is best because it ties view lifecycle to data lifecycle

File Organization

Sources/{ViewsTarget}/
├── {Feature}/
│   ├── {Feature}View.swift             # Full page → {Feature}ViewModel
│   ├── {Entity}CardView.swift          # Child component → {Entity}CardViewModel
│   ├── {Entity}RowView.swift           # Child component → {Entity}RowViewModel
│   └── {Modal}View.swift               # Modal → {Modal}ViewModel
├── Shared/
│   ├── HeaderView.swift                # Shared components
│   └── FooterView.swift
└── Styles/
    └── ButtonStyles.swift              # Reusable button styles

---

Common Mistakes

Computing Data in Views

// ❌ BAD - View is transforming data
var body: some View {
    Text("\(viewModel.firstName) \(viewModel.lastName)")
}

// ✅ GOOD - ViewModel provides shaped result
var body: some View {
    Text(viewModel.fullName)  // via @LocalizedCompoundString
}

Forgetting to Call toggleRepaint()

// ❌ BAD - Test infrastructure won't work
private func submit() {
    operations.submit()
    // Missing toggleRepaint()!
}

// ✅ GOOD - Always call after operations
private func submit() {
    operations.submit()
    toggleRepaint()
}

Using Computed Properties for Display

// ❌ BAD - View is computing
var body: some View {
    if !viewModel.items.isEmpty {
        Text("You have \(viewModel.items.count) items")
    }
}

// ✅ GOOD - ViewModel provides the state
var body: some View {
    if viewModel.hasItems {
        Text(viewModel.itemCountMessage)
    }
}

Hardcoding Text

// ❌ BAD - Not localizable
Button(action: submit) {
    Text("Submit")
}

// ✅ GOOD - ViewModel provides localized text
Button(action: submit) {
    Text(viewModel.submitButtonLabel)
}

Missing Error Binding

// ❌ BAD - Errors not handled
Button(action: submit) {
    Text(viewModel.submitLabel)
}

// ✅ GOOD - Error binding for async actions
Button(errorBinding: $error, asyncAction: submit) {
    Text(viewModel.submitLabel)
}

Storing Operations in Body Instead of Init

// ❌ BAD - Recomputed on every render
public var body: some View {
    let operations = viewModel.operations
    Button(action: { operations.submit() }) {
        Text(viewModel.submitLabel)
    }
}

// ✅ GOOD - Store in init
private let operations: any MyOperations

public init(viewModel: MyViewModel) {
    self.viewModel = viewModel
    self.operations = viewModel.operations
}

Mismatched Filenames

// ❌ BAD - Filename doesn't match ViewModel
ViewModel: TaskListViewModel
View:      TasksView.swift

// ✅ GOOD - Aligned names
ViewModel: TaskListViewModel
View:      TaskListView.swift

Incorrect ViewModelId Initialization

// ❌ BAD - Generic identity, views won't update correctly
public var vmId: ViewModelId = .init()

// ✅ MINIMUM - Type-based identity
public var vmId: ViewModelId = .init(type: Self.self)

// ✅ IDEAL - Data-based identity (when id available)
public init(id: ModelIdType) {
    self.id = id
    self.vmId = .init(id: id)
}

Force-Unwrapping Localizable Strings

// ❌ BAD - Force-unwrapping to work around missing overload
import SwiftUI

Text(try! viewModel.title.localizedString)  // Anti-pattern - don't do this!
Label(try! viewModel.label.localizedString, systemImage: "star")

// ✅ GOOD - Request the proper SwiftUI overload instead
// The correct solution is to add an init extension like this:
extension Text {
    public init(_ localizable: Localizable) {
        self.init(localizable.localized)
    }
}

extension Label where Title == Text, Icon == Image {
    public init(_ title: Localizable, systemImage: String) {
        self.init(title.localized, systemImage: systemImage)
    }
}

// Then views use it cleanly without force-unwraps:
Text(viewModel.title)
Label(viewModel.label, systemImage: "star")

Why this matters:

FOSMVVM provides the Localizable protocol for all localized strings and includes SwiftUI init overloads for common elements like Text. However, not every SwiftUI element has a Localizable overload yet.

When you encounter a SwiftUI element that doesn't accept Localizable directly:

1. DON'T work around it with try! localizable.localizedString - this bypasses the type system and spreads force-unwrap calls throughout the view code
2. DO request that we add the proper init overload to FOSUtilities for that SwiftUI element
3. The pattern is simple: Extensions that accept Localizable and pass .localized to the standard initializer

This approach keeps the codebase clean, type-safe, and eliminates force-unwraps from view code entirely.

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File Templates

See reference.md for complete file templates.

Naming Conventions

Concept	Convention	Example
View struct	{Name}View	TaskListView, SignInView
ViewModel property	viewModel	Always viewModel
Operations property	operations	Always operations
Error state	error	Always error
Repaint toggle	repaintToggle	Always repaintToggle

Common Modifiers

FOSMVVM-Specific Modifiers

// Error alert with ViewModel strings
.alert(
    errorBinding: $error,
    title: viewModel.errorTitle,
    message: viewModel.errorMessage,
    dismissButtonLabel: viewModel.dismissButtonLabel
)

// Async task with error handling
.task(errorBinding: $error) {
    try await loadData()
}

// Async submit handler
.onAsyncSubmit {
    await submit()
}

// Test data transporter (DEBUG only)
.testDataTransporter(viewModelOps: operations, repaintToggle: $repaintToggle)

// UI testing identifier
.uiTestingIdentifier("submitButton")

Standard SwiftUI Modifiers

Apply standard modifiers as needed for layout, styling, etc.

How to Use This Skill

Invocation:

/fosmvvm-swiftui-view-generator

Prerequisites:

• ViewModel and its structure are understood from conversation
• Optionally, specification files have been read into context
• View requirements (display-only, interactive, form, container) are clear from discussion

Output:

• {ViewName}View.swift - SwiftUI view conforming to ViewModelView protocol

Workflow integration: This skill is typically used after discussing requirements or reading specification files. The skill references that context automatically—no file paths or Q&A needed.

See Also

• Architecture Patterns - Mental models and patterns
• FOSMVVMArchitecture.md - Full FOSMVVM architecture
• fosmvvm-viewmodel-generator - For creating ViewModels
• fosmvvm-ui-tests-generator - For creating UI tests
• reference.md - Complete file templates

Version History

Version	Date	Changes
1.0	2026-01-23	Initial skill for SwiftUI view generation
1.1	2026-05-03	Operations section rewrite to align with ConversationPractice/docs/architecture.md: surface the framework/app-side seam (<Name>Operations.swift / <Name>StubOps.swift / <Name>Ops.swift file convention), distinguish FOSMVVM.ViewModelOperations from per-feature protocols, note App Intents/transport actions share the same protocol, document toggleRepaint() motivation, clarify async vs sync op shape, promote display-only-no-Operations decision to a top-level rule. Clarify the storage-vs-method-signature distinction: any is acceptable at single-value View storage (Swift 5.7+ implicit existential opening preserves generic specialization at call sites); generics are required at protocol method signatures. All View examples updated to private let operations: any <Name>ViewModelOperations.