react-native-architecture

What this skill does

# React Native Architecture

Production-ready patterns for React Native development with Expo, including navigation, state management, native modules, and offline-first architecture.

## When to Use This Skill

- Starting a new React Native or Expo project
- Implementing complex navigation patterns
- Integrating native modules and platform APIs
- Building offline-first mobile applications
- Optimizing React Native performance
- Setting up CI/CD for mobile releases

## Core Concepts

### 1. Project Structure

```
src/
├── app/                    # Expo Router screens
│   ├── (auth)/            # Auth group
│   ├── (tabs)/            # Tab navigation
│   └── _layout.tsx        # Root layout
├── components/
│   ├── ui/                # Reusable UI components
│   └── features/          # Feature-specific components
├── hooks/                 # Custom hooks
├── services/              # API and native services
├── stores/                # State management
├── utils/                 # Utilities
└── types/                 # TypeScript types
```

### 2. Expo vs Bare React Native

| Feature            | Expo           | Bare RN        |
| ------------------ | -------------- | -------------- |
| Setup complexity   | Low            | High           |
| Native modules     | EAS Build      | Manual linking |
| OTA updates        | Built-in       | Manual setup   |
| Build service      | EAS            | Custom CI      |
| Custom native code | Config plugins | Direct access  |

## Quick Start

```bash
# Create new Expo project
npx create-expo-app@latest my-app -t expo-template-blank-typescript

# Install essential dependencies
npx expo install expo-router expo-status-bar react-native-safe-area-context
npx expo install @react-native-async-storage/async-storage
npx expo install expo-secure-store expo-haptics
```

```typescript
// app/_layout.tsx
import { Stack } from 'expo-router'
import { ThemeProvider } from '@/providers/ThemeProvider'
import { QueryProvider } from '@/providers/QueryProvider'

export default function RootLayout() {
  return (
    <QueryProvider>
      <ThemeProvider>
        <Stack screenOptions={{ headerShown: false }}>
          <Stack.Screen name="(tabs)" />
          <Stack.Screen name="(auth)" />
          <Stack.Screen name="modal" options={{ presentation: 'modal' }} />
        </Stack>
      </ThemeProvider>
    </QueryProvider>
  )
}
```

## Patterns

### Pattern 1: Expo Router Navigation

```typescript
// app/(tabs)/_layout.tsx
import { Tabs } from 'expo-router'
import { Home, Search, User, Settings } from 'lucide-react-native'
import { useTheme } from '@/hooks/useTheme'

export default function TabLayout() {
  const { colors } = useTheme()

  return (
    <Tabs
      screenOptions={{
        tabBarActiveTintColor: colors.primary,
        tabBarInactiveTintColor: colors.textMuted,
        tabBarStyle: { backgroundColor: colors.background },
        headerShown: false,
      }}
    >
      <Tabs.Screen
        name="index"
        options={{
          title: 'Home',
          tabBarIcon: ({ color, size }) => <Home size={size} color={color} />,
        }}
      />
      <Tabs.Screen
        name="search"
        options={{
          title: 'Search',
          tabBarIcon: ({ color, size }) => <Search size={size} color={color} />,
        }}
      />
      <Tabs.Screen
        name="profile"
        options={{
          title: 'Profile',
          tabBarIcon: ({ color, size }) => <User size={size} color={color} />,
        }}
      />
      <Tabs.Screen
        name="settings"
        options={{
          title: 'Settings',
          tabBarIcon: ({ color, size }) => <Settings size={size} color={color} />,
        }}
      />
    </Tabs>
  )
}

// app/(tabs)/profile/[id].tsx - Dynamic route
import { useLocalSearchParams } from 'expo-router'

export default function ProfileScreen() {
  const { id } = useLocalSearchParams<{ id: string }>()

  return <UserProfile userId={id} />
}

// Navigation from anywhere
import { router } from 'expo-router'

// Programmatic navigation
router.push('/profile/123')
router.replace('/login')
router.back()

// With params
router.push({
  pathname: '/product/[id]',
  params: { id: '123', referrer: 'home' },
})
```

### Pattern 2: Authentication Flow

```typescript
// providers/AuthProvider.tsx
import { createContext, useContext, useEffect, useState } from 'react'
import { useRouter, useSegments } from 'expo-router'
import * as SecureStore from 'expo-secure-store'

interface AuthContextType {
  user: User | null
  isLoading: boolean
  signIn: (credentials: Credentials) => Promise<void>
  signOut: () => Promise<void>
}

const AuthContext = createContext<AuthContextType | null>(null)

export function AuthProvider({ children }: { children: React.ReactNode }) {
  const [user, setUser] = useState<User | null>(null)
  const [isLoading, setIsLoading] = useState(true)
  const segments = useSegments()
  const router = useRouter()

  // Check authentication on mount
  useEffect(() => {
    checkAuth()
  }, [])

  // Protect routes
  useEffect(() => {
    if (isLoading) return

    const inAuthGroup = segments[0] === '(auth)'

    if (!user && !inAuthGroup) {
      router.replace('/login')
    } else if (user && inAuthGroup) {
      router.replace('/(tabs)')
    }
  }, [user, segments, isLoading])

  async function checkAuth() {
    try {
      const token = await SecureStore.getItemAsync('authToken')
      if (token) {
        const userData = await api.getUser(token)
        setUser(userData)
      }
    } catch (error) {
      await SecureStore.deleteItemAsync('authToken')
    } finally {
      setIsLoading(false)
    }
  }

  async function signIn(credentials: Credentials) {
    const { token, user } = await api.login(credentials)
    await SecureStore.setItemAsync('authToken', token)
    setUser(user)
  }

  async function signOut() {
    await SecureStore.deleteItemAsync('authToken')
    setUser(null)
  }

  if (isLoading) {
    return <SplashScreen />
  }

  return (
    <AuthContext.Provider value={{ user, isLoading, signIn, signOut }}>
      {children}
    </AuthContext.Provider>
  )
}

export const useAuth = () => {
  const context = useContext(AuthContext)
  if (!context) throw new Error('useAuth must be used within AuthProvider')
  return context
}
```

### Pattern 3: Offline-First with React Query

```typescript
// providers/QueryProvider.tsx
import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
import { createAsyncStoragePersister } from '@tanstack/query-async-storage-persister'
import { PersistQueryClientProvider } from '@tanstack/react-query-persist-client'
import AsyncStorage from '@react-native-async-storage/async-storage'
import NetInfo from '@react-native-community/netinfo'
import { onlineManager } from '@tanstack/react-query'

// Sync online status
onlineManager.setEventListener((setOnline) => {
  return NetInfo.addEventListener((state) => {
    setOnline(!!state.isConnected)
  })
})

const queryClient = new QueryClient({
  defaultOptions: {
    queries: {
      gcTime: 1000 * 60 * 60 * 24, // 24 hours
      staleTime: 1000 * 60 * 5, // 5 minutes
      retry: 2,
      networkMode: 'offlineFirst',
    },
    mutations: {
      networkMode: 'offlineFirst',
    },
  },
})

const asyncStoragePersister = createAsyncStoragePersister({
  storage: AsyncStorage,
  key: 'REACT_QUERY_OFFLINE_CACHE',
})

export function QueryProvider({ children }: { children: React.ReactNode }) {
  return (
    <PersistQueryClientProvider
      client={queryClient}
      persistOptions={{ persister: asyncStoragePersister }}
    >
      {children}
    </PersistQueryClientProvider>
  )
}

// hooks/useProducts.ts
import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query'

export function useProducts() {
  return useQuery({
    queryKey: ['products'],
    queryFn: api.getProducts,
    // Use stale data while revalidating
    placeholderData: (previousData) => previousData,
  })
}

export function use