Building Redux from Scratch in SwiftUI: Production-Ready Implementation

Originally published on Medium

---

🤔 The Problem with SwiftUI State Management

You start with @State for simple views. Then you discover @StateObject for more complex scenarios. Everything's great until...

• Your user data needs to be shared across 5 unrelated screens
• The shopping cart needs to persist when users switch tabs
• Search filters affect multiple view hierarchies
• You need analytics tracking every user action

Suddenly, you're passing data down through 6 levels of view hierarchy, creating "god objects" that know too much, and debugging state changes becomes a nightmare.

🎯 Why Redux? (And Why Most Tutorials Miss the Point)

Most Redux tutorials show you how to build a counter. Increment, decrement, done. But that's not why you'd actually use Redux.

Redux shines when:

• Multiple screens need the same data
• State changes need to be predictable and debuggable
• You have complex business logic that needs testing
• Async operations need coordination with UI state

🛠️ What I Built: A Real Shopping Cart App

Instead of toy examples, I built a complete shopping cart application demonstrating production patterns:

Core Features

• User Authentication with realistic error scenarios
• Product Catalog with search and filtering
• Shopping Cart with persistence across app launches
• Real-time Updates across all tabs and views
• Comprehensive Error Handling for network failures

Production Patterns

• Type-Safe Actions preventing runtime errors
• Middleware System for async operations, logging, analytics, and persistence
• Performance Optimization with selective state observation
• Mock Data System for immediate development and testing

🏗️ The Architecture That Actually Works

// Actions that tell the story
UserActions.login(email: "[e-mail]", password: "password")
CartActions.addItem(productId: "iphone-15", quantity: 1)
ProductActions.searchProducts(query: "iPhone")

// State that reflects reality
struct AppState {
    var user: UserState      // Login status, user info, errors
    var cart: CartState      // Items, quantities, checkout status
    var products: ProductState // Catalog, search results, filters
    var ui: UIState         // Navigation, toasts, loading
}

// Middleware that handles the messy stuff
Action → Logging → Async → Analytics → Persistence → Reducer → New State

🎮 See It in Action

The complete implementation includes patterns you won't find in basic tutorials:

Real User Flows

• Login with [e-mail] to see error handling
• Add products and switch tabs to see real-time updates
• Close the app and reopen to see persistence working
• Test network failures and offline scenarios

SwiftUI Integration Done Right

• No unnecessary re-renders thanks to ViewStore pattern
• Proper error boundaries with user-friendly messages
• Loading states that actually feel responsive
• Navigation that plays nicely with Redux state

💻 Complete Implementation Available

Everything discussed is implemented in a working app you can run immediately:

🔗 GitHub Repository

What you'll find:

• ✅ 15+ SwiftUI views with full Redux integration
• ✅ Complete middleware system
• ✅ Mock data with realistic scenarios
• ✅ Error handling throughout
• ✅ Testing examples
• ✅ Production patterns you can adapt

🎯 Key Takeaways

Redux isn't about following web patterns in iOS. It's about solving real problems:

1. Predictable State Flow - Every change goes through the same path
2. Separation of Concerns - Business logic in reducers, side effects in middleware
3. Testing Made Simple - Pure functions are easy to test
4. Performance Control - Update only what actually changed

When to use Redux:

• Large teams needing predictable patterns
• Complex apps with lots of shared state
• Apps requiring comprehensive testing
• When debugging state changes is critical

When NOT to use Redux:

• Simple apps with local state
• Prototypes and MVPs
• When Apple's tools work fine

🚀 Ready to Build Better State Management?

Read the full implementation guide and get the complete source code:

📖 Full Article on Medium

💻 Complete Code on GitHub

---

What's your experience with state management in SwiftUI? Have you hit the point where @State and @ObservableObject aren't enough? Share your thoughts in the comments!