[Xcode/Swift] APNs完全理解：iOSのプッシュ通知を設計・実装・運用までざっくり解説

import SwiftUI
import UserNotifications

@main
struct APNsDemoApp: App {
    @UIApplicationDelegateAdaptor(AppDelegate.self) var appDelegate

    var body: some Scene {
        WindowGroup {
            ContentView()
        }
    }
}

final class AppDelegate: NSObject, UIApplicationDelegate, UNUserNotificationCenterDelegate {
    func application(_ application: UIApplication,
                     didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]? = nil) -> Bool {
        let center = UNUserNotificationCenter.current()
        center.delegate = self
        Task {
            // リクエストを投げて許可をもらう、requestAuthorization は UNUserNotificationCenter。必要に応じて .provisional も検討。
            let granted = try? await center.requestAuthorization(options: [.alert, .badge, .sound])
            if granted == true { await MainActor.run { UIApplication.shared.registerForRemoteNotifications() } }
        }
        return true
    }
}

extension AppDelegate {
  func application(_ application: UIApplication,
                   didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
    let token = deviceToken.map { String(format: "%02x", $0) }.joined() // hex
    // 例: 自社APIへ登録する
    sendTokenToServer(token)
  }

  // 登録失敗
  func application(_ application: UIApplication,
                   didFailToRegisterForRemoteNotificationsWithError error: Error) {
    print("APNs registration failed: \(error)")
  }
}

// アプリ前面でもバナー等を出したい場合
// .banner / .list / .badge / .sound などで制御。
func userNotificationCenter(_ center: UNUserNotificationCenter,
  willPresent notification: UNNotification,
  withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
  completionHandler([.banner, .sound, .badge]) // iOS 14+
}

// 起動時にカテゴリ登録
func application(_ application: UIApplication, didFinishLaunchingWithOptions _: [UIApplication.LaunchOptionsKey: Any]? = nil) -> Bool {
    let reply = UNTextInputNotificationAction(identifier: "reply", title: "返信", options: [])
    let open  = UNNotificationAction(identifier: "open", title: "開く", options: [.foreground])
    let category = UNNotificationCategory(identifier: "message", actions: [reply, open], intentIdentifiers: [])
    UNUserNotificationCenter.current().setNotificationCategories()
    ...
    return true
}

func userNotificationCenter(_ center: UNUserNotificationCenter,
                            didReceive response: UNNotificationResponse,
                            withCompletionHandler completionHandler: @escaping () -> Void) {
    let userInfo = response.notification.request.content.userInfo
    // userInfoからURL等を取り出しDeep Linkへ
    completionHandler()
}

// NotificationService.swift
import UserNotifications

final class NotificationService: UNNotificationServiceExtension {
    private var contentHandler: ((UNNotificationContent) -> Void)?
    private var bestAttemptContent: UNMutableNotificationContent?

    override func didReceive(
        _ request: UNNotificationRequest,
        withContentHandler contentHandler: @escaping (UNNotificationContent) -> Void
    ) {
        self.contentHandler = contentHandler
        bestAttemptContent = (request.content.mutableCopy() as? UNMutableNotificationContent)

        // 例: 画像URLをダウンロードして添付
        if let urlString = request.content.userInfo["image"] as? String,
           let url = URL(string: urlString),
           let data = try? Data(contentsOf: url) {
            let tmp = URL(fileURLWithPath: NSTemporaryDirectory()).appendingPathComponent("image.jpg")
            try? data.write(to: tmp)
            if let attachment = try? UNNotificationAttachment(identifier: "image", url: tmp) {
                bestAttemptContent?.attachments = [attachment]
            }
        }
        if let modified = bestAttemptContent { contentHandler(modified) }
    }

    override func serviceExtensionTimeWillExpire() {
        if let bestAttemptContent { contentHandler?(bestAttemptContent) }
    }
}

import ActivityKit

struct OrderAttributes: ActivityAttributes {
  public struct ContentState: Codable, Hashable {
    var progress: Double
  }
  var orderID: String
}

// 開始
let activity = try? Activity<OrderAttributes>.request(
  attributes: .init(orderID: "1234"),
  contentState: .init(progress: 0.1),
  pushType: .token) // ← push token を取得可能に
// pushTokenの監視
Task {
  for await tokenData in activity?.pushTokenUpdates ?? AsyncStream { _ in } {
    let token = tokenData.map { String(format: "%02x", $0) }.joined()
    // サーバへ登録
  }
}

// アラート通知
{
  "aps": {
    "alert": { "title": "お知らせ", "body": "本文です" },
    "badge": 1,
    "sound": "default",
    "interruption-level": "active",    // or "time-sensitive"/"critical"
    "relevance-score": 0.8
  },
  "deepLink": "myapp://article/42"
}

// サイレント（バックグラウンド更新）
// content-available だけにし、Background Modes → Remote notifications を有効化しておく。
{ "aps": { "content-available": 1 } }

curl -v --http2 \
  -H "apns-topic: com.example.myapp" \
  -H "apns-push-type: alert" \
  -H "apns-priority: 10" \
  -H "authorization: bearer $JWT" \
  --data '{"aps":{"alert":{"title":"Hi","body":"From curl"},"sound":"default","badge":1}}' \
  https://api.sandbox.push.apple.com/3/device/<DEVICE_TOKEN>

curl -v --http2 \
  -H "apns-topic: com.example.myapp.push-type.liveactivity" \
  -H "apns-push-type: liveactivity" \
  -H "authorization: bearer $JWT" \
  --data '{"aps":{"timestamp": 1724550000}, "content-state":{"progress":0.6}}' \
  https://api.push.apple.com/3/device/<LIVE_ACTIVITY_PUSH_TOKEN>

import Foundation
import CryptoKit

func makeJWT(keyID: String, teamID: String, p8PrivateKeyPEM: String) throws -> String {
    let header = ["alg":"ES256", "kid": keyID]
    let claims = ["iss": teamID, "iat": Int(Date().timeIntervalSince1970)]

    func b64(_ obj: Any) -> String {
        let data = try! JSONSerialization.data(withJSONObject: obj)
        return data.base64EncodedString().replacingOccurrences(of: "=", with: "")
            .replacingOccurrences(of: "/", with: "_").replacingOccurrences(of: "+", with: "-")
    }

    let signingInput = [b64(header), b64(claims)].joined(separator: ".")
    // p8 -> SecKey の生成は割愛（既存ユーティリティを利用推奨）
    let privateKey = try loadECPrivateKeyFromP8(p8PrivateKeyPEM) // 実装は各環境に合わせて
    let signature = try signES256(input: signingInput, privateKey: privateKey)
    return signingInput + "." + signature
}

{ "aps": { "alert":"Test", "sound":"default", "badge":1 }, "deeplink":"myapp://foo" }

xcrun simctl push booted com.example.myapp payload.apns

// willPresent / didReceive / token登録 など本記事のサンプルをコピペ

# alert
curl --http2 -H "apns-topic: <BUNDLE_ID>" \
 -H "apns-push-type: alert" -H "apns-priority: 10" \
 -H "authorization: bearer <JWT>" \
 --data '{"aps":{"alert":{"title":"Title","body":"Body"}}}' \
 https://api.push.apple.com/3/device/<DEVICE_TOKEN>

# background
curl --http2 -H "apns-topic: <BUNDLE_ID>" \
 -H "apns-push-type: background" -H "apns-priority: 5" \
 -H "authorization: bearer <JWT>" \
 --data '{"aps":{"content-available":1}}' \
 https://api.push.apple.com/3/device/<DEVICE_TOKEN>

# liveactivity
curl --http2 -H "apns-topic: <BUNDLE_ID>.push-type.liveactivity" \
 -H "apns-push-type: liveactivity" \
 -H "authorization: bearer <JWT>" \
 --data '{"aps":{"timestamp": 1724550000}, "content-state":{"progress":0.5}}' \
 https://api.push.apple.com/3/device/<LIVE_ACTIVITY_PUSH_TOKEN>