notifications

Local Notifications

Use this guide when implementing or modifying notification features.

Framework

UserNotifications — UNUserNotificationCenter.current()

Permission States (CRITICAL — handle ALL four)

1. Not Determined — Call .requestAuthorization(options: [.alert, .badge, .sound]). System shows dialog.
2. Authorized — Schedule notifications normally.
3. Denied — App CANNOT re-request. Must redirect user to System Settings.
4. Provisional — Quiet notifications. Treat as authorized.

Permission Is System-Controlled

• Once denied, the app has NO way to re-request — only the user can re-enable in System Settings.
• To open Settings: UIApplication.shared.open(URL(string: UIApplication.openSettingsURLString)!)

UI Rules for Notification Status

• .notDetermined — Show "Enable Notifications" button that calls requestAuthorization. After dialog, re-check and update UI.
• .authorized / .provisional — Show enabled state (bell icon). Read-only — user disables in Settings.
• .denied — Show "bell.slash" icon + "Open Settings" button. Show helper text explaining system control.
• NEVER use a writable Toggle for notification permission — the app cannot grant/revoke it. Use buttons with state-specific actions.

Re-Check on Foreground (CRITICAL)

Any view displaying notification status MUST re-check when app returns to foreground:

.onReceive(NotificationCenter.default.publisher(for: UIApplication.willEnterForegroundNotification)) { _ in
    Task {
        let settings = await UNUserNotificationCenter.current().notificationSettings()
        isEnabled = (settings.authorizationStatus == .authorized || settings.authorizationStatus == .provisional)
    }
}

Scheduling

let content = UNMutableNotificationContent()
content.title = "Reminder"
content.body = "Time to check in"
content.sound = .default

// Time-based
let trigger = UNTimeIntervalNotificationTrigger(timeInterval: 3600, repeats: false)

// Calendar-based (daily at specific time)
var dateComponents = DateComponents()
dateComponents.hour = 20
dateComponents.minute = 0
let trigger = UNCalendarNotificationTrigger(dateMatching: dateComponents, repeats: true)

let request = UNNotificationRequest(identifier: "reminder", content: content, trigger: trigger)
try await UNUserNotificationCenter.current().add(request)