Grep: class.*ObservableObject
Grep: : ObservableObject
Grep: @Published

// ❌ LEGACY (iOS 14-16)
class ContentViewModel: ObservableObject {
    @Published var items: [Item] = []
    @Published var isLoading = false
    @Published var errorMessage: String?
}

// ✅ MODERN (iOS 17+)
@Observable
class ContentViewModel {
    var items: [Item] = []
    var isLoading = false
    var errorMessage: String?

    // Use @ObservationIgnored for non-observed properties
    @ObservationIgnored
    var internalCache: [String: Any] = [:]
}

Grep: @StateObject

// ❌ LEGACY
struct ContentView: View {
    @StateObject private var viewModel = ContentViewModel()

    var body: some View { ... }
}

// ✅ MODERN (with @Observable model)
struct ContentView: View {
    @State private var viewModel = ContentViewModel()

    var body: some View { ... }
}

Grep: @ObservedObject

// ❌ LEGACY
struct ItemView: View {
    @ObservedObject var item: ItemModel

    var body: some View {
        Text(item.name)
    }
}

// ✅ MODERN - Direct property (read-only access)
struct ItemView: View {
    var item: ItemModel  // No wrapper needed!

    var body: some View {
        Text(item.name)
    }
}

// ✅ MODERN - @Bindable (for two-way binding)
struct ItemEditorView: View {
    @Bindable var item: ItemModel

    var body: some View {
        TextField("Name", text: $item.name)  // Binding works
    }
}

Grep: @EnvironmentObject
Grep: \.environmentObject\(

// ❌ LEGACY - Setting
ContentView()
    .environmentObject(settings)

// ❌ LEGACY - Reading
struct SettingsView: View {
    @EnvironmentObject var settings: AppSettings

    var body: some View { ... }
}

// ✅ MODERN - Setting
ContentView()
    .environment(settings)

// ✅ MODERN - Reading
struct SettingsView: View {
    @Environment(AppSettings.self) var settings

    var body: some View { ... }
}

// ✅ MODERN - With binding
struct SettingsEditorView: View {
    @Environment(AppSettings.self) var settings

    var body: some View {
        @Bindable var settings = settings
        Toggle("Dark Mode", isOn: $settings.darkMode)
    }
}

Grep: \.onChange\(of:.*perform:

// ❌ DEPRECATED
.onChange(of: searchText) { newValue in
    performSearch(newValue)
}

// ✅ MODERN (iOS 17+)
.onChange(of: searchText) { oldValue, newValue in
    performSearch(newValue)
}

// ✅ With initial execution
.onChange(of: searchText, initial: true) { oldValue, newValue in
    performSearch(newValue)
}

Grep: completion:\s*@escaping
Grep: completionHandler:
Grep: DispatchQueue\.main\.async

// ❌ LEGACY
func fetchUser(id: String, completion: @escaping (Result<User, Error>) -> Void) {
    URLSession.shared.dataTask(with: url) { data, response, error in
        DispatchQueue.main.async {
            if let error = error {
                completion(.failure(error))
                return
            }
            // Parse and return
            completion(.success(user))
        }
    }.resume()
}

// ✅ MODERN
func fetchUser(id: String) async throws -> User {
    let (data, _) = try await URLSession.shared.data(from: url)
    return try JSONDecoder().decode(User.self, from: data)
}

Grep: withAnimation.*\{

// ❌ LEGACY
withAnimation(.spring()) {
    isExpanded.toggle()
}

// ✅ MODERN (simple cases)
isExpanded.toggle()
// Apply animation to view:
.animation(.spring(), value: isExpanded)

// Or use new binding animation:
$isExpanded.animation(.spring()).wrappedValue.toggle()

Grep: Date\(\)
Grep: CGFloat
Grep: replacingOccurrences
Grep: DateFormatter\(\)
Grep: \.filter\(.*\)\.count
Grep: Task\.sleep\(nanoseconds:

Glob: **/*.swift

Grep: ObservableObject
Grep: @Published

Grep: @StateObject|@ObservedObject|@EnvironmentObject

Grep: onChange\(of:.*perform:

Grep: completion:\s*@escaping
Grep: completionHandler:

# Modernization Analysis Results

## Summary
- **HIGH Priority**: [count] (Significant performance/maintainability gains)
- **MEDIUM Priority**: [count] (Deprecated APIs, code quality)
- **LOW Priority**: [count] (Minor improvements)

## Minimum Deployment Target Impact
- Current patterns support: iOS 14+
- After full modernization: iOS 17+

## HIGH Priority Migrations

### ObservableObject → @Observable

**Files affected**: 5
**Estimated effort**: 2-3 hours

#### Models to Migrate

1. `Models/ContentViewModel.swift:12`
   ```swift
   // Current
   class ContentViewModel: ObservableObject {
       @Published var items: [Item] = []
       @Published var isLoading = false
   }

   // Migrated
   @Observable
   class ContentViewModel {
       var items: [Item] = []
       var isLoading = false
   }

## When No Migration Needed

```markdown
# Modernization Analysis Results

## Summary
Codebase is already using modern patterns!

## Verified
- ✅ Using `@Observable` macro
- ✅ Using `@State` with Observable models
- ✅ Using `@Environment` for shared state
- ✅ No deprecated modifiers detected

## Optional Improvements
- Consider adopting iOS 18+ features when available
- Review remaining completion handlers for async/await conversion

Is model a class with published properties?
├─ YES: Does it conform to ObservableObject?
│  ├─ YES: Target iOS 17+?
│  │  ├─ YES → Migrate to @Observable
│  │  └─ NO → Keep ObservableObject
│  └─ NO: Already modern or not observable
└─ NO: Check if it's a struct (usually fine)

Is view using @StateObject?
├─ YES: Is the model @Observable?
│  ├─ YES → Change to @State
│  └─ NO → Keep @StateObject until model migrated
└─ NO: Check other wrappers

Is view using @ObservedObject?
├─ YES: Is the model @Observable?
│  ├─ YES: Need binding?
│  │  ├─ YES → Use @Bindable
│  │  └─ NO → Remove wrapper, use plain property
│  └─ NO → Keep @ObservedObject
└─ NO: Already modern

Is view using @EnvironmentObject?
├─ YES: Is the model @Observable?
│  ├─ YES → Change to @Environment(Type.self)
│  └─ NO → Keep @EnvironmentObject
└─ NO: Already modern