iOS Background Processing: BGTask, Push ve Silent Notifications

1// 1. Info.plist'e ekle
2// BGTaskSchedulerPermittedIdentifiers: [
3//     "com.app.refresh",
4//     "com.app.processing"
5// ]
6 
7// 2. AppDelegate'de kayıt
8class AppDelegate: UIResponder, UIApplicationDelegate {
9    func application(
10        _ application: UIApplication,
11        didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
12    ) -> Bool {
13 
14        // Background App Refresh task
15        BGTaskScheduler.shared.register(
16            forTaskWithIdentifier: "com.app.refresh",
17            using: nil
18        ) { task in
19            self.handleAppRefresh(task: task as! BGAppRefreshTask)
20        }
21 
22        // Background Processing task
23        BGTaskScheduler.shared.register(
24            forTaskWithIdentifier: "com.app.processing",
25            using: nil
26        ) { task in
27            self.handleProcessing(task: task as! BGProcessingTask)
28        }
29 
30        return true
31    }
32}

1// Kısa süreli görevler (30 saniye max)
2func handleAppRefresh(task: BGAppRefreshTask) {
3    // Sonraki refresh'i zamanla
4    scheduleAppRefresh()
5 
6    // Expiration handler
7    task.expirationHandler = {
8        // Temizlik: devam eden işleri iptal et
9        URLSession.shared.getAllTasks { tasks in
10            tasks.forEach { $0.cancel() }
11        }
12    }
13 
14    // Veri güncelleme
15    Task {
16        do {
17            let newData = try await fetchLatestContent()
18            await updateLocalCache(with: newData)
19            task.setTaskCompleted(success: true)
20        } catch {
21            task.setTaskCompleted(success: false)
22        }
23    }
24}
25 
26func scheduleAppRefresh() {
27    let request = BGAppRefreshTaskRequest(identifier: "com.app.refresh")
28    request.earliestBeginDate = Date(timeIntervalSinceNow: 15 * 60) // 15 dk sonra
29 
30    do {
31        try BGTaskScheduler.shared.submit(request)
32    } catch {
33        print("Refresh schedule failed: \(error)")
34    }
35}
36 
37// Scene lifecycle'da çağır
38func sceneDidEnterBackground(_ scene: UIScene) {
39    scheduleAppRefresh()
40}

1// Uzun süreli görevler (cihaz şarjda + Wi-Fi'da)
2func handleProcessing(task: BGProcessingTask) {
3    scheduleProcessing()
4 
5    let operationQueue = OperationQueue()
6    operationQueue.maxConcurrentOperationCount = 1
7 
8    task.expirationHandler = {
9        operationQueue.cancelAllOperations()
10    }
11 
12    let operation = DataSyncOperation()
13    operation.completionBlock = {
14        task.setTaskCompleted(success: !operation.isCancelled)
15    }
16 
17    operationQueue.addOperation(operation)
18}
19 
20func scheduleProcessing() {
21    let request = BGProcessingTaskRequest(identifier: "com.app.processing")
22    request.requiresNetworkConnectivity = true
23    request.requiresExternalPower = false // true = sadece şarjda
24    request.earliestBeginDate = Date(timeIntervalSinceNow: 60 * 60) // 1 saat
25 
26    do {
27        try BGTaskScheduler.shared.submit(request)
28    } catch {
29        print("Processing schedule failed: \(error)")
30    }
31}
32 
33// DataSync Operation
34class DataSyncOperation: Operation {
35    override func main() {
36        guard !isCancelled else { return }
37 
38        // 1. Offline değişiklikleri al
39        let pendingChanges = CoreDataManager.shared.pendingChanges()
40 
41        for change in pendingChanges {
42            guard !isCancelled else { break }
43 
44            // 2. Sunucuya gönder
45            let semaphore = DispatchSemaphore(value: 0)
46            APIClient.shared.sync(change) { result in
47                if case .success = result {
48                    CoreDataManager.shared.markSynced(change)
49                }
50                semaphore.signal()
51            }
52            semaphore.wait()
53        }
54    }
55}

1// Uygulama kapalıyken bile indirme/yükleme
2class BackgroundDownloadManager: NSObject {
3    static let shared = BackgroundDownloadManager()
4 
5    private lazy var session: URLSession = {
6        let config = URLSessionConfiguration.background(
7            withIdentifier: "com.app.background-download"
8        )
9        config.isDiscretionary = true // Sistem en uygun zamanı seçer
10        config.sessionSendsLaunchEvents = true // Bitince uygulamayı uyandır
11        config.allowsCellularAccess = false // Sadece Wi-Fi
12        return URLSession(configuration: config, delegate: self, delegateQueue: nil)
13    }()
14 
15    func downloadFile(from url: URL) -> URLSessionDownloadTask {
16        let task = session.downloadTask(with: url)
17        task.earliestBeginDate = Date(timeIntervalSinceNow: 60)
18        task.countOfBytesClientExpectsToSend = 200  // Header boyutu
19        task.countOfBytesClientExpectsToReceive = 5 * 1024 * 1024  // ~5MB
20        task.resume()
21        return task
22    }
23}
24 
25extension BackgroundDownloadManager: URLSessionDownloadDelegate {
26    func urlSession(
27        _ session: URLSession,
28        downloadTask: URLSessionDownloadTask,
29        didFinishDownloadingTo location: URL
30    ) {
31        // Geçici dosyayı kalıcı konuma taşı
32        let documentsURL = FileManager.default.urls(
33            for: .documentDirectory, in: .userDomainMask
34        )[0]
35        let destURL = documentsURL.appendingPathComponent(
36            downloadTask.originalRequest?.url?.lastPathComponent ?? "download"
37        )
38 
39        try? FileManager.default.moveItem(at: location, to: destURL)
40    }
41 
42    func urlSession(
43        _ session: URLSession,
44        task: URLSessionTask,
45        didCompleteWithError error: Error?
46    ) {
47        if let error {
48            print("Download failed: \(error.localizedDescription)")
49        }
50    }
51 
52    func urlSession(
53        _ session: URLSession,
54        downloadTask: URLSessionDownloadTask,
55        didWriteData bytesWritten: Int64,
56        totalBytesWritten: Int64,
57        totalBytesExpectedToWrite: Int64
58    ) {
59        let progress = Double(totalBytesWritten) / Double(totalBytesExpectedToWrite)
60        print("Download progress: \(Int(progress * 100))%")
61    }
62}
63 
64// AppDelegate'de completion handler
65func application(
66    _ application: UIApplication,
67    handleEventsForBackgroundURLSession identifier: String,
68    completionHandler: @escaping() -> Void
69) {
70    // Session'a completion handler'ı aktar
71    BackgroundDownloadManager.shared.backgroundCompletionHandler = completionHandler
72}

1// Server tarafı payload
2// {
3//     "aps": {
4//         "content-available": 1   // Silent push flag
5//     },
6//     "custom-data": "sync-needed"
7// }
8 
9// AppDelegate'de handle etme
10func application(
11    _ application: UIApplication,
12    didReceiveRemoteNotification userInfo: [AnyHashable: Any],
13    fetchCompletionHandler completionHandler: @escaping(UIBackgroundFetchResult) -> Void
14) {
15    // 30 saniye süre var!
16    guard let action = userInfo["custom-data"] as? String else {
17        completionHandler(.noData)
18        return
19    }
20 
21    Task {
22        switch action {
23        case "sync-needed":
24            let hasNewData = await syncWithServer()
25            completionHandler(hasNewData ? .newData : .noData)
26 
27        case "config-update":
28            await refreshConfiguration()
29            completionHandler(.newData)
30 
31        default:
32            completionHandler(.noData)
33        }
34    }
35}

1// SwiftUI App lifecycle
2@main
3struct MyApp: App {
4    @UIApplicationDelegateAdaptor(AppDelegate.self) var appDelegate
5 
6    var body: some Scene {
7        WindowGroup {
8            ContentView()
9        }
10        .backgroundTask(.appRefresh("com.app.refresh")) {
11            await handleRefresh()
12        }
13    }
14 
15    func handleRefresh() async {
16        // Sonraki schedule
17        let request = BGAppRefreshTaskRequest(identifier: "com.app.refresh")
18        request.earliestBeginDate = .now.addingTimeInterval(30 * 60)
19        try? BGTaskScheduler.shared.submit(request)
20 
21        // İş mantığı
22        let hasUpdates = await DataSyncService.shared.checkForUpdates()
23        if hasUpdates {
24            await DataSyncService.shared.sync()
25        }
26    }
27}

1// Significant location change (pil dostu)
2let locationManager = CLLocationManager()
3locationManager.startMonitoringSignificantLocationChanges()
4 
5// Geofencing (passive, düşük pil)
6let region = CLCircularRegion(
7    center: CLLocationCoordinate2D(latitude: 41.0082, longitude: 28.9784),
8    radius: 200,
9    identifier: "office"
10)
11region.notifyOnEntry = true
12region.notifyOnExit = true
13locationManager.startMonitoring(for: region)

1// AVAudioSession background playback
2import AVFoundation
3 
4func configureAudioSession() {
5    let session = AVAudioSession.sharedInstance()
6    try? session.setCategory(.playback, mode: .default, options: [])
7    try? session.setActive(true)
8}
9 
10// Now Playing info (Lock Screen & Control Center)
11func updateNowPlaying(title: String, artist: String, duration: TimeInterval) {
12    var info = [String: Any]()
13    info[MPMediaItemPropertyTitle] = title
14    info[MPMediaItemPropertyArtist] = artist
15    info[MPMediaItemPropertyPlaybackDuration] = duration
16    info[MPNowPlayingInfoPropertyElapsedPlaybackTime] = player.currentTime
17    MPNowPlayingInfoCenter.default().nowPlayingInfo = info
18}

1Arka plan görevi mı?
2├── Kısa(<30sn)?
3│   ├── Push ile tetiklenen → Silent Push
4│   └── Periyodik → BGAppRefreshTask
5├── Uzun(dakikalar)?
6│   └── BGProcessingTask(şarj + Wi-Fi)
7├── İndirme/Yükleme?
8│   └── Background URLSession
9├── Sürekli?
10│   ├── Konum → Significant Location Change
11│   ├── Ses → AVAudioSession .playback
12│   ├── VoIP → PushKit
13│   └── BLE → Core Bluetooth background
14└── Hiçbiri → beginBackgroundTask(son çare, ~30sn)