SKILL.md
iOS Notifications
Expert guidance for implementing push and local notifications in iOS apps.
Setup
Request Permission
import UserNotifications
class NotificationManager: ObservableObject {
static let shared = NotificationManager()
@Published var isAuthorized = false
func requestPermission() async -> Bool {
do {
let granted = try await UNUserNotificationCenter.current()
.requestAuthorization(options: [.alert, .badge, .sound])
await MainActor.run {
isAuthorized = granted
}
return granted
} catch {
print("Notification permission error: \(error)")
return false
}
}
func checkPermissionStatus() async {
let settings = await UNUserNotificationCenter.current().notificationSettings()
await MainActor.run {
isAuthorized = settings.authorizationStatus == .authorized
}
}
}Register for Push Notifications
// In AppDelegate
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
UIApplication.shared.registerForRemoteNotifications()
return true
}
func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
let token = deviceToken.map { String(format: "%02.2hhx", $0) }.joined()
print("Device Token: \(token)")
// Send token to your server
}
func application(_ application: UIApplication, didFailToRegisterForRemoteNotificationsWithError error: Error) {
print("Failed to register: \(error)")
}Local Notifications
Schedule Notification
func scheduleNotification(
title: String,
body: String,
delay: TimeInterval,
identifier: String = UUID().uuidString
) async throws {
let content = UNMutableNotificationContent()
content.title = title
content.body = body
content.sound = .default
content.badge = 1
let trigger = UNTimeIntervalNotificationTrigger(
timeInterval: delay,
repeats: false
)
let request = UNNotificationRequest(
identifier: identifier,
content: content,
trigger: trigger
)
try await UNUserNotificationCenter.current().add(request)
}Schedule at Specific Time
func scheduleDaily(at hour: Int, minute: Int, title: String, body: String) async throws {
let content = UNMutableNotificationContent()
content.title = title
content.body = body
content.sound = .default
var dateComponents = DateComponents()
dateComponents.hour = hour
dateComponents.minute = minute
let trigger = UNCalendarNotificationTrigger(
dateMatching: dateComponents,
repeats: true
)
let request = UNNotificationRequest(
identifier: "daily-reminder",
content: content,
trigger: trigger
)
try await UNUserNotificationCenter.current().add(request)
}Schedule with Location
import CoreLocation
func scheduleLocationNotification(
title: String,
body: String,
coordinate: CLLocationCoordinate2D,
radius: CLLocationDistance = 100
) async throws {
let content = UNMutableNotificationContent()
content.title = title
content.body = body
content.sound = .default
let region = CLCircularRegion(
center: coordinate,
radius: radius,
identifier: "location-trigger"
)
region.notifyOnEntry = true
region.notifyOnExit = false
let trigger = UNLocationNotificationTrigger(region: region, repeats: false)
let request = UNNotificationRequest(
identifier: UUID().uuidString,
content: content,
trigger: trigger
)
try await UNUserNotificationCenter.current().add(request)
}Cancel Notifications
func cancelNotification(identifier: String) {
UNUserNotificationCenter.current().removePendingNotificationRequests(withIdentifiers: [identifier])
}
func cancelAllNotifications() {
UNUserNotificationCenter.current().removeAllPendingNotificationRequests()
}
func cancelDeliveredNotifications() {
UNUserNotificationCenter.current().removeAllDeliveredNotifications()
}Notification Actions
Define Categories
func setupNotificationCategories() {
// Action buttons
let acceptAction = UNNotificationAction(
identifier: "ACCEPT_ACTION",
title: "Accept",
options: [.foreground]
)
let declineAction = UNNotificationAction(
identifier: "DECLINE_ACTION",
title: "Decline",
options: [.destructive]
)
// Text input action
let replyAction = UNTextInputNotificationAction(
identifier: "REPLY_ACTION",
title: "Reply",
options: [],
textInputButtonTitle: "Send",
textInputPlaceholder: "Type your reply..."
)
// Category
let inviteCategory = UNNotificationCategory(
identifier: "INVITE_CATEGORY",
actions: [acceptAction, declineAction],
intentIdentifiers: [],
options: []
)
let messageCategory = UNNotificationCategory(
identifier: "MESSAGE_CATEGORY",
actions: [replyAction],
intentIdentifiers: [],
options: []
)
UNUserNotificationCenter.current().setNotificationCategories([inviteCategory, messageCategory])
}Use Category
func sendInviteNotification() async throws {
let content = UNMutableNotificationContent()
content.title = "New Invitation"
content.body = "John invited you to an event"
content.categoryIdentifier = "INVITE_CATEGORY"
let request = UNNotificationRequest(
identifier: UUID().uuidString,
content: content,
trigger: nil // Deliver immediately
)
try await UNUserNotificationCenter.current().add(request)
}Handle Actions
class NotificationDelegate: NSObject, UNUserNotificationCenterDelegate {
func userNotificationCenter(
_ center: UNUserNotificationCenter,
didReceive response: UNNotificationResponse
) async {
let actionIdentifier = response.actionIdentifier
switch actionIdentifier {
case "ACCEPT_ACTION":
handleAccept(response.notification)
case "DECLINE_ACTION":
handleDecline(response.notification)
case "REPLY_ACTION":
if let textResponse = response as? UNTextInputNotificationResponse {
handleReply(textResponse.userText, notification: response.notification)
}
case UNNotificationDefaultActionIdentifier:
// User tapped notification
handleTap(response.notification)
default:
break
}
}
// Show notification while app in foreground
func userNotificationCenter(
_ center: UNUserNotificationCenter,
willPresent notification: UNNotification
) async -> UNNotificationPresentationOptions {
return [.banner, .sound, .badge]
}
}
// Set delegate in App
@main
struct MyApp: App {
@UIApplicationDelegateAdaptor(AppDelegate.self) var appDelegate
init() {
UNUserNotificationCenter.current().delegate = NotificationDelegate()
}
}Rich Notifications
With Image
func sendImageNotification(imageURL: URL) async throws {
let content = UNMutableNotificationContent()
content.title = "New Photo"
content.body = "Check out this image"
// Download and attach image
let (localURL, _) = try await URLSession.shared.download(from: imageURL)
let attachment = try UNNotificationAttachment(
identifier: "image",
url: localURL,
options: nil
)
content.attachments = [attachment]
let request = UNNotificationRequest(
identifier: UUID().uuidString,
content: content,
trigger: nil
)
try await UNUserNotificationCenter.current().add(request)
}With Custom Data
func sendNotificationWithData(userInfo: [AnyHashable: Any]) async throws {
let content = UNMutableNotificationContent()
content.title = "New Message"
content.body = "You have a new message"
content.userInfo = userInfo // Custom data
let request = UNNotificationRequest(
identifier: UUID().uuidString,
content: content,
trigger: nil
)
try await UNUserNotificationCenter.current().add(request)
}
// Access in delegate
func handleNotification(_ notification: UNNotification) {
let userInfo = notification.request.content.userInfo
if let messageID = userInfo["messageID"] as? String {
// Navigate to message
}
}Badge Management
func updateBadge(count: Int) async {
try? await UNUserNotificationCenter.current().setBadgeCount(count)
}
func clearBadge() async {
try? await UNUserNotificationCenter.current().setBadgeCount(0)
}Push Notification Payload
Standard Payload
{
"aps": {
"alert": {
"title": "New Message",
"subtitle": "From John",
"body": "Hey, how are you?"
},
"badge": 5,
"sound": "default",
"category": "MESSAGE_CATEGORY"
},
"messageID": "12345",
"senderID": "user123"
}Silent Push
{
"aps": {
"content-available": 1
},
"data": {
"type": "sync"
}
}Notification Service Extension
Create Extension
- File > New > Target > Notification Service Extension
class NotificationService: UNNotificationServiceExtension {
var contentHandler: ((UNNotificationContent) -> Void)?
var bestAttemptContent: UNMutableNotificationContent?
override func didReceive(
_ request: UNNotificationRequest,
withContentHandler contentHandler: @escaping (UNNotificationContent) -> Void
) {
self.contentHandler = contentHandler
bestAttemptContent = (request.content.mutableCopy() as? UNMutableNotificationContent)
guard let content = bestAttemptContent else {
contentHandler(request.content)
return
}
// Modify content
content.title = "[Modified] " + content.title
// Download and attach image
if let imageURLString = content.userInfo["imageURL"] as? String,
let imageURL = URL(string: imageURLString) {
downloadImage(url: imageURL) { attachment in
if let attachment = attachment {
content.attachments = [attachment]
}
contentHandler(content)
}
} else {
contentHandler(content)
}
}
override func serviceExtensionTimeWillExpire() {
if let contentHandler = contentHandler,
let content = bestAttemptContent {
contentHandler(content)
}
}
}