State & Data Flow

State Management

Two Zustand stores in lib/store.ts:

useAuthStore

Field	Type	Description
user	User | null	Current authenticated user
isAuthenticated	boolean	Whether a user is signed in
setUser(user)	action	Set user and isAuthenticated
logout()	action	Clear user state

Written by: Login screen, logout action Read by: Profile screen, Place Detail (review gate)

useMapStore

Field	Type	Description
region	{ latitude, longitude, latitudeDelta, longitudeDelta }	Current map viewport
selectedPlaceId	string | null	Currently selected marker
categories	string[]	Active category filter IDs
acsAttrs	string[]	Active accessibility attribute filters
setRegion(region)	action	Update viewport
setSelectedPlaceId(id)	action	Select a marker
setCategories(ids)	action	Update category filters
setAcsAttrs(attrs)	action	Update ACS filters

Written by: Map screen (region changes, marker selection), Search Modal (filters, search result selection) Read by: usePlaces (region, categories, acsAttrs), Map screen (selectedPlaceId for marker highlighting)

Data Flow

How places get from the database to the screen:

tRPC Integration

The mobile client connects to the same tRPC API the web app uses via lib/api.ts.

Platform-aware base URL (getBaseUrl()):

• Web: http://localhost:3000
• Native (dev): Uses Constants.expoConfig.hostUri to extract the LAN IP, e.g. http://192.168.1.x:3000
• Production: https://enaccessmaps.com

Client setup:

export const api = createTRPCReact<AppRouter>();

export function createTRPCClient() {
  return api.createClient({
    links: [
      httpBatchLink({
        url: `${BASE_URL}/api/trpc`,
        async headers() {
          return {};
        },
      }),
    ],
  });
}

The AppRouter type is imported from @enaccess/shared, which re-exports it from the main app's tRPC router definition. This gives the mobile client full type safety on all procedure calls.

Key procedures used:

• place.searchPlacesByBounds — spatial search by map bounds
• place.searchGooglePlaces — text search via Google Places API
• category.getAll — fetch all place categories

The TRPCProvider (lib/trpc-provider.tsx) wraps the app with both the tRPC provider and QueryClientProvider from TanStack Query.

Authentication Flow

Session management (lib/auth.ts):

• Tokens stored in expo-secure-store (encrypted native storage)
• getStoredSession() / storeSession() for session token
• getStoredUser() / storeUser() for cached user data
• clearSession() removes both on logout