Firebase İleri Seviye: Offline-First, Security Rules ve Cloud Functions

1import FirebaseFirestore
2 
3// Composite query (birden fazla alan filtresi)
4func getActiveExpensiveProducts() async throws -> [Product] {
5    let snapshot = try await Firestore.firestore()
6        .collection("products")
7        .whereField("isActive", isEqualTo: true)
8        .whereField("price", isGreaterThan: 100)
9        .order(by: "price", descending: true)
10        .limit(to: 20)
11        .getDocuments()
12 
13    return snapshot.documents.compactMap { try? $0.data(as: Product.self) }
14}
15 
16// Collection group query (tüm subcollection'ları tara)
17func getAllReviews(rating: Int) async throws -> [Review] {
18    let snapshot = try await Firestore.firestore()
19        .collectionGroup("reviews")
20        .whereField("rating", isGreaterThanOrEqualTo: rating)
21        .getDocuments()
22 
23    return snapshot.documents.compactMap { try? $0.data(as: Review.self) }
24}
25 
26// Pagination ile cursor-based sayfalama
27class PaginatedFetcher {
28    private var lastDocument: DocumentSnapshot?
29 
30    func fetchNextPage() async throws -> [Product] {
31        var query = Firestore.firestore()
32            .collection("products")
33            .order(by: "createdAt", descending: true)
34            .limit(to: 20)
35 
36        if let last = lastDocument {
37            query = query.start(afterDocument: last)
38        }
39 
40        let snapshot = try await query.getDocuments()
41        lastDocument = snapshot.documents.last
42 
43        return snapshot.documents.compactMap { try? $0.data(as: Product.self) }
44    }
45}
46 
47// Real-time listener
48func listenToOrders() -> ListenerRegistration {
49    return Firestore.firestore()
50        .collection("orders")
51        .whereField("userId", isEqualTo: Auth.auth().currentUser!.uid)
52        .addSnapshotListener { snapshot, error in
53            guard let documents = snapshot?.documents else { return }
54            let orders = documents.compactMap { try? $0.data(as: Order.self) }
55            self.orders = orders
56        }
57}

1// Firestore otomatik offline persistence (varsayılan açık, 100MB cache)
2let settings = FirestoreSettings()
3settings.cacheSettings = PersistentCacheSettings(sizeBytes: 200 * 1024 * 1024) // 200MB
4Firestore.firestore().settings = settings
5 
6// Offline yazma — queue'ya alınır, bağlantı gelince sync olur
7func saveOrder(_ order: Order) async throws {
8    try Firestore.firestore()
9        .collection("orders")
10        .document(order.id)
11        .setData(from: order)
12    // Offline'da bile çalışır - queue'ya alınır
13}
14 
15// Cache vs server source belirt
16func getProduct(id: String, source: FirestoreSource = .default) async throws -> Product {
17    let doc = try await Firestore.firestore()
18        .collection("products")
19        .document(id)
20        .getDocument(source: source)  // .cache, .server, .default
21        .data(as: Product.self)
22    return doc
23}

1// firestore.rules
2rules_version = '2';
3service cloud.firestore {
4  match /databases/{database}/documents {
5    // Users - sadece kendi profili
6    match /users/{userId} {
7      allow read: if request.auth != null;
8      allow write: if request.auth.uid == userId;
9    }
10 
11    // Products - herkes okuyabilir, admin yazabilir
12    match /products/{productId} {
13      allow read: if true;
14      allow write: if request.auth.token.admin == true;
15 
16      // Validation
17      allow create: if request.resource.data.name is string
18                    && request.resource.data.name.size() > 0
19                    && request.resource.data.price is number
20                    && request.resource.data.price > 0;
21    }
22 
23    // Orders - sadece kendi siparişleri
24    match /orders/{orderId} {
25      allow read: if request.auth.uid == resource.data.userId;
26      allow create: if request.auth.uid == request.resource.data.userId
27                    && request.resource.data.items.size() > 0;
28      allow update: if false; // Sipariş değiştirilemez
29    }
30  }
31}

1// functions/src/index.ts
2import * as functions from 'firebase-functions';
3import * as admin from 'firebase-admin';
4admin.initializeApp();
5 
6// Yeni sipariş oluşturulduğunda
7export const onOrderCreated = functions.firestore
8  .document('orders/{orderId}')
9  .onCreate(async (snap, context) => {
10    const order = snap.data();
11 
12    // Stok düş
13    for (const item of order.items) {
14      await admin.firestore()
15        .collection('products')
16        .doc(item.productId)
17        .update({ stock: admin.firestore.FieldValue.increment(-item.quantity) });
18    }
19 
20    // Email gönder
21    await sendOrderConfirmation(order.userId, context.params.orderId);
22 
23    // Push notification
24    const user = await admin.firestore().collection('users').doc(order.userId).get();
25    const token = user.data()?.fcmToken;
26    if (token) {
27      await admin.messaging().send({
28        token,
29        notification: {
30          title: 'Sipariş Onayı',
31          body: 'Sipariş #' + context.params.orderId + ' alındı!',
32        },
33      });
34    }
35  });
36 
37// Scheduled function - günlük temizlik
38export const dailyCleanup = functions.pubsub
39  .schedule('every 24 hours')
40  .onRun(async () => {
41    const thirtyDaysAgo = new Date(Date.now() - 30 * 24 * 60 * 60 * 1000);
42    const old = await admin.firestore()
43      .collection('logs')
44      .where('createdAt', '<', thirtyDaysAgo)
45      .get();
46    const batch = admin.firestore().batch();
47    old.docs.forEach(doc => batch.delete(doc.ref));
48    await batch.commit();
49  });

1// Custom claims ile role-based auth
2// Cloud Function ile claim ata
3// admin.auth().setCustomUserClaims(uid, { admin: true })
4 
5// iOS'ta claim kontrol
6func checkAdminAccess() async throws -> Bool {
7    guard let user = Auth.auth().currentUser else { return false }
8    let result = try await user.getIDTokenResult()
9    return result.claims["admin"] as? Bool ?? false
10}

1import FirebaseRemoteConfig
2 
3func setupRemoteConfig() {
4    let config = RemoteConfig.remoteConfig()
5    config.setDefaults(["new_feature_enabled": false as NSObject])
6    config.fetchAndActivate { status, error in
7        let isEnabled = config.configValue(forKey: "new_feature_enabled").boolValue
8        if isEnabled { self.showNewFeature() }
9    }
10}

1# Firebase Extensions kurulumu
2firebase ext:install firebase/firestore-send-email
3firebase ext:install firebase/storage-resize-images
4firebase ext:install firebase/firestore-translate-text

1// YANLIS: Derin nesting ve fazla subcollection
2// users/{userId}/orders/{orderId}/items/{itemId}/reviews/{reviewId}
3 
4// DOGRU: Flat yapı + denormalization
5// users/{userId}
6// orders/{orderId}  → userId field'ı ile ilişki
7// orderItems/{itemId} → orderId field'ı ile ilişki
8 
9// Denormalization örneği - sipariş içine ürün bilgisi göm
10struct Order: Codable {
11    let id: String
12    let userId: String
13    let status: String
14    let totalAmount: Double
15    let items: [OrderItem]  // Embed, ayrı sorgu gerekmez
16 
17    struct OrderItem: Codable {
18        let productId: String
19        let productName: String   // Denormalized
20        let productImage: String  // Denormalized
21        let quantity: Int
22        let unitPrice: Double
23    }
24}
25 
26// Aggregation ile sayaç tutma (okuma maliyetini düşürür)
27func incrementProductViewCount(productId: String) async throws {
28    let ref = Firestore.firestore().collection("products").document(productId)
29    try await ref.updateData([
30        "viewCount": FieldValue.increment(Int64(1)),
31        "lastViewedAt": FieldValue.serverTimestamp()
32    ])
33}