iOS Form Builder

Generate comprehensive form infrastructure for iOS applications including field components, validation, multi-step coordinators, and form state management.

When to Use This Skill

Use this skill when building:

• Mortgage application forms - Multi-step loan applications with validation
• User profile forms - Registration and profile update flows
• Data collection forms - Property information, financial data entry
• Multi-step wizards - Complex flows with navigation and progress tracking
• Document upload forms - Forms with camera/photo integration
• Pre-qualification forms - Forms with real-time calculations

Quick Start

1. Generate Form Components

python3 scripts/generate_form_components.py ./output

Generates:

• FormField.swift - Form field protocols and implementations (550+ lines)
• FormFieldViews.swift - SwiftUI views for rendering fields (400+ lines)

2. Generate Multi-Step Coordinator

python3 scripts/generate_form_coordinator.py ./output

Generates:

• FormCoordinator.swift - Multi-step form management (350+ lines)
• FormState.swift - Auto-save and state persistence (150+ lines)

3. Implement Your Form

See references/form_patterns.md for complete implementation examples.

Core Components

Form Field Types

TextFormField - Text input with validation

• Email validation
• Phone number validation
• Custom regex patterns
• Min/max length
• Required fields

NumberFormField - Numeric input with constraints

• Min/max values
• Decimal places
• Currency formatting
• Percentage inputs

DateFormField - Date selection

• Min/max date ranges
• Date/time/both modes
• Custom date picker UI

PickerFormField - Single selection

• Dropdown picker
• Segmented control
• Custom options

ToggleFormField - Boolean switch

• Always valid
• Default values

MultiSelectFormField - Multiple selection

• Checkboxes
• Min/max selections
• Validation rules

Validation System

Built-in validators:

• EmailValidationRule - Email format
• PhoneValidationRule - Phone number format
• MinLengthValidationRule - Minimum characters
• MaxLengthValidationRule - Maximum characters
• RegexValidationRule - Custom patterns
• CustomValidationRule - Custom logic

Cross-field validation:

func validate() -> Bool {
    // Validate individual fields
    guard field1.validate(), field2.validate() else {
        return false
    }
    
    // Cross-field validation
    if field1.value > field2.value {
        field2.errorMessage = "Must be greater than field 1"
        return false
    }
    
    return true
}

Multi-Step Forms

FormCoordinator - Manages multi-step flows

• Progress tracking
• Step navigation (next/back/jump)
• Validation per step
• Optional steps
• Cancel with confirmation

AutoSaveFormCoordinator - Auto-saves form state

• Automatic state persistence
• Configurable save interval
• State restoration on load
• Clear saved state after submit

FormCoordinatorView - Pre-built SwiftUI view

• Progress bar
• Step indicator
• Navigation buttons
• Validation alerts
• Cancel confirmation

Conditional Fields

Show/hide fields based on other field values:

let conditionalManager = ConditionalFieldManager()

conditionalManager.addCondition(fieldId: "condoFee") {
    propertyTypeField.value == "condo"
}

Integration

SwiftUI Component Library (Skill #7)

Use enhanced currency/percentage inputs:

CurrencyInputField(
    value: $field.value,
    label: field.label
)

Data Persistence (Skill #8)

Auto-save to Core Data or UserDefaults:

class PersistentFormCoordinator: FormCoordinator {
    func saveFormData() {
        try context.save()
    }
}

Privacy & Permissions (Skill #10)

Document upload with camera:

await permissionManager.requestPermission(.camera)
await permissionManager.requestPermission(.photoLibrary)

Financial Calculator (Skill #9)

Real-time mortgage calculations:

let payment = calculator.calculateMonthlyPayment(
    principal: loanAmount,
    annualRate: rate,
    years: term
)

PDF Export (Skill #5)

Export completed forms to PDF:

let exporter = FormPDFExporter()
let pdfURL = try await exporter.exportFormToPDF(data: formData)

Common Patterns

Mortgage Application Form

See references/form_patterns.md section "Multi-Step Forms" for complete mortgage application example with:

• Personal information step
• Property details step
• Financial information step
• Employment information step
• Review and submit step

Simple Contact Form

See references/form_patterns.md section "Basic Form Patterns" for contact form with:

• Name field (required)
• Email field (validated)
• Phone field (optional)
• Submit validation

Conditional Property Form

See references/form_patterns.md section "Conditional Fields" for property form with:

• Property type picker
• Conditional condo fee (if condo)
• Conditional HOA fee (if single family)

Form with Auto-Save

See references/form_patterns.md section "Multi-Step Forms" for auto-save example with:

• Automatic state persistence every 30 seconds
• State restoration on app launch
• Clear state after submission

Reference Documentation

Complete Patterns and Examples

Read references/form_patterns.md for:

• Basic form patterns (contact, number input, date, picker)
• Multi-step form examples (mortgage application)
• Conditional field patterns
• Pre-filling from persistence
• Custom validation (cross-field, async)
• Form submission patterns

Integration with Other Skills

Read references/integration_guide.md for:

• SwiftUI Component Library integration
• Data Persistence (Core Data, UserDefaults)
• PDF export from forms
• Privacy & permissions (camera, biometrics)
• Financial calculator integration

Best Practices

Form Field Design

1. Always mark required fields - Use red asterisk
2. Provide clear labels - Self-explanatory field names
3. Show inline validation - Real-time error messages
4. Use appropriate keyboards - .emailAddress, .phonePad, .decimalPad
5. Set sensible defaults - Pre-populate when possible

Multi-Step Forms

1. Show progress clearly - Progress bar + "Step X of Y"
2. Allow back navigation - Never trap users
3. Validate per step - Don't let invalid data through
4. Auto-save frequently - Every 30 seconds or on step change
5. Add review step - Let users verify before submit

Validation

1. Validate on blur - Don't validate while typing
2. Show specific errors - "Email must contain @" not "Invalid"
3. Use cross-field validation - Check relationships between fields
4. Async validation carefully - Don't block the UI
5. Clear errors on fix - Remove error when field becomes valid

State Management

1. Auto-save state - Prevent data loss
2. Restore state - Resume where user left off
3. Clear on submit - Remove saved state after success
4. Handle conflicts - Deal with stale data gracefully

Generated Code Structure

Output Directory/
├── FormField.swift (550+ lines)
│   ├── FormField protocol
│   ├── TextFormField
│   ├── NumberFormField
│   ├── DateFormField
│   ├── PickerFormField
│   ├── ToggleFormField
│   ├── MultiSelectFormField
│   └── Validation rules
├── FormFieldViews.swift (400+ lines)
│   ├── TextFormFieldView
│   ├── NumberFormFieldView
│   ├── DateFormFieldView
│   ├── PickerFormFieldView
│   ├── ToggleFormFieldView
│   └── MultiSelectFormFieldView
├── FormCoordinator.swift (350+ lines)
│   ├── FormStep protocol
│   ├── FormCoordinator class
│   ├── FormCoordinatorView
│   ├── StepNavigationView
│   └── ConditionalFieldManager
└── FormState.swift (150+ lines)
    ├── FormStateManager
    ├── FormData protocol
    └── AutoSaveFormCoordinator

Total: ~1,450 lines of production-ready Swift code

Example Use Cases

1. Mortgage Pre-Qualification Form

// Create form with financial fields
let incomeField = NumberFormField(id: "income", label: "Monthly Income", isRequired: true)
let debtsField = NumberFormField(id: "debts", label: "Monthly Debts", isRequired: true)
let downPaymentField = NumberFormField(id: "down", label: "Down Payment", isRequired: true)

// Real-time affordability calculation
let maxHomePrice = calculator.calculateAffordability(
    monthlyIncome: incomeField.value,
    monthlyDebts: debtsField.value,
    downPayment: downPaymentField.value
)

2. User Registration Form

let nameField = TextFormField(id: "name", label: "Full Name", isRequired: true)
let emailField = TextFormField(
    id: "email",
    label: "Email",
    isRequired: true,
    validationRules: [EmailValidationRule()],
    keyboardType: .emailAddress
)
let passwordField = TextFormField(
    id: "password",
    label: "Password",
    isRequired: true,
    validationRules: [MinLengthValidationRule(minLength: 8)]
)

3. Property Information Form

// Conditional fields based on property type
let propertyTypeField = PickerFormField<String>(
    id: "type",
    label: "Property Type",
    options: [
        .init("singleFamily", label: "Single Family"),
        .init("condo", label: "Condominium")
    ]
)

// Only show condo fee if condo selected
conditionalManager.addCondition(fieldId: "condoFee") {
    propertyTypeField.value == "condo"
}

4. Document Upload Form

// Request camera permission
await permissionManager.requestPermission(.camera)

// Upload document photos
class DocumentUploadStep: FormStep {
    @Published var documents: [UIImage] = []
    
    func addDocument(_ image: UIImage) {
        documents.append(image)
    }
}

Tips

• Start simple - Build basic forms first, add multi-step later
• Test validation - Ensure all edge cases are handled
• Use auto-save - Prevent user data loss
• Integrate early - Connect with persistence and PDF export
• Follow patterns - Use examples from form_patterns.md
• Reuse components - Don't rebuild field types
• Clear error messages - Users should understand what's wrong
• Test on device - Keyboard and navigation feel different

Troubleshooting

Fields not validating?

• Call field.validate() before checking field.isValid
• Check if validation rules are added correctly

Multi-step form not advancing?

• Ensure current step validation passes
• Check isOptional flag for optional steps

Auto-save not working?

• Verify FormData conforms to Codable
• Check UserDefaults or Core Data setup

Conditional fields not hiding?

• Verify condition closure returns correct boolean
• Rebuild view when condition changes

Form state not restoring?

• Check form key matches between saves
• Ensure FormData decoding succeeds