Local Notifications in iOS Development
1. Introduction to Local Notifications
Local notifications are a way to notify users about important events even when your app is not running in the foreground. Unlike push notifications, local notifications are scheduled and triggered by the app itself.
2. Setting Up Your Project
Before you can start using local notifications, you need to set up your iOS project to request permission from the user and handle notifications.
Step 1: Open your Xcode project and navigate to Info.plist. Add a new key called Privacy - Notifications Usage Description and provide a description for why you need notifications.
3. Requesting Notification Permissions
In your app delegate, you need to request permission to show notifications.
Example Code:
import UIKit
import UserNotifications
@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
var window: UIWindow?
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .sound, .badge]) { granted, error in
if granted {
print("Permission granted")
} else {
print("Permission denied")
}
}
return true
}
}
4. Scheduling a Local Notification
Once you have permission, you can schedule a local notification.
Example Code:
import UserNotifications
func scheduleLocalNotification() {
let content = UNMutableNotificationContent()
content.title = "Hello!"
content.body = "This is a local notification."
content.sound = UNNotificationSound.default
let trigger = UNTimeIntervalNotificationTrigger(timeInterval: 5, repeats: false)
let request = UNNotificationRequest(identifier: UUID().uuidString, content: content, trigger: trigger)
UNUserNotificationCenter.current().add(request) { error in
if let error = error {
print("Error scheduling notification: \(error)")
} else {
print("Notification scheduled!")
}
}
}
5. Handling Notification Actions
To handle actions when a user interacts with your notification, implement the UNUserNotificationCenterDelegate methods.
Example Code:
import UserNotifications
class NotificationHandler: NSObject, UNUserNotificationCenterDelegate {
func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: @escaping () -> Void) {
// Handle the notification action
let userInfo = response.notification.request.content.userInfo
print("Notification received with userInfo: \(userInfo)")
completionHandler()
}
func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
// Handle the notification while the app is in the foreground
completionHandler([.alert, .sound])
}
}
6. Conclusion
Local notifications are a powerful way to engage users by providing timely and relevant information. By following this tutorial, you should now be able to set up, schedule, and handle local notifications in your iOS applications.