Ios Swift Development

# iOS Swift Development

## Table of Contents

- [Overview](#overview)
- [When to Use](#when-to-use)
- [Quick Start](#quick-start)
- [Reference Guides](#reference-guides)
- [Best Practices](#best-practices)

## Overview

Build high-performance native iOS applications using Swift with modern frameworks including SwiftUI, Combine, and async/await patterns.

## When to Use

- Creating native iOS applications with optimal performance
- Leveraging iOS-specific features and APIs
- Building apps that require tight hardware integration
- Using SwiftUI for declarative UI development
- Implementing complex animations and transitions

## Quick Start

Minimal working example:

```swift
import Foundation
import Combine

struct User: Codable, Identifiable {
  let id: UUID
  var name: String
  var email: String
}

class UserViewModel: ObservableObject {
  @Published var user: User?
  @Published var isLoading = false
  @Published var errorMessage: String?

  private let networkService: NetworkService

  init(networkService: NetworkService = .shared) {
    self.networkService = networkService
  }

  @MainActor
  func fetchUser(id: UUID) async {
    isLoading = true
    errorMessage = nil

// ... (see reference guides for full implementation)
```

## Reference Guides

Detailed implementations in the `references/` directory:

| Guide | Contents |
|---|---|
| [MVVM Architecture Setup](references/mvvm-architecture-setup.md) | MVVM Architecture Setup |
| [Network Service with URLSession](references/network-service-with-urlsession.md) | Network Service with URLSession |
| [SwiftUI Views](references/swiftui-views.md) | SwiftUI Views |

## Best Practices

### ✅ DO

- Use SwiftUI for modern UI development
- Implement MVVM architecture
- Use async/await patterns
- Store sensitive data in Keychain
- Handle errors gracefully
- Use @StateObject for ViewModels
- Validate API responses properly
- Implement Core Data for persistence
- Test on multiple iOS versions
- Use dependency injection
- Follow Swift style guidelines

### ❌ DON'T

- Store tokens in UserDefaults
- Make network calls on main thread
- Use deprecated UIKit patterns
- Ignore memory leaks
- Skip error handling
- Use force unwrapping (!)
- Store passwords in code
- Ignore accessibility
- Deploy untested code
- Use hardcoded API URLs


# API Endpoint Scaffold
# TODO: Customize for your API framework

openapi: "3.0.3"
info:
  title: "API Service"
  version: "1.0.0"

paths:
  /api/v1/resource:
    get:
      summary: "List resources"
      # TODO: Define parameters and responses
      responses:
        "200":
          description: "Success"
    post:
      summary: "Create resource"
      # TODO: Define request body and responses
      responses:
        "201":
          description: "Created"


# SwiftUI Views

## SwiftUI Views

```swift
struct ContentView: View {
  @StateObject var userViewModel = UserViewModel()

  var body: some View {
    TabView {
      HomeView()
        .tabItem { Label("Home", systemImage: "house") }

      ProfileView(viewModel: userViewModel)
        .tabItem { Label("Profile", systemImage: "person") }
    }
  }
}

struct HomeView: View {
  @State var items: [Item] = []
  @State var loading = true

  var body: some View {
    NavigationView {
      ZStack {
        if loading {
          ProgressView()
        } else {
          List(items) { item in
            NavigationLink(destination: ItemDetailView(item: item)) {
              VStack(alignment: .leading) {
                Text(item.title).font(.headline)
                Text(item.description).font(.subheadline).foregroundColor(.gray)
              }
            }
          }
        }
      }
      .navigationTitle("Items")
      .task {
        await loadItems()
      }
    }
  }

  private func lo