Send the local notifications like so:
func sendNotification(title: String, subtitle: String, body: String, timeInterval: TimeInterval) {
let center = UNUserNotificationCenter.current()
center.getPendingNotificationRequests(completionHandler: { pendingNotificationRequests in
//Use the main thread since we want to access UIApplication.shared.applicationIconBadgeNumber
DispatchQueue.main.sync {
//Create the new content
let content = UNMutableNotificationContent()
content.title = title
content.subtitle = subtitle
content.body = body
//Let's store the firing date of this notification in content.userInfo
let firingDate = Date().timeIntervalSince1970 + timeInterval
content.userInfo = ["timeInterval": firingDate]
//get the count of pending notification that will be fired earlier than this one
let earlierNotificationsCount: Int = pendingNotificationRequests.filter { request in
let userInfo = request.content.userInfo
if let time = userInfo["timeInterval"] as? Double {
if time < firingDate {
return true
} else {
//Here we update the notofication that have been created earlier, BUT have a later firing date
let newContent: UNMutableNotificationContent = request.content.mutableCopy() as! UNMutableNotificationContent
newContent.badge = (Int(truncating: request.content.badge ?? 0) + 1) as NSNumber
let newRequest: UNNotificationRequest =
UNNotificationRequest(identifier: request.identifier,
content: newContent,
trigger: request.trigger)
center.add(newRequest, withCompletionHandler: { (error) in
// Handle error
})
return false
}
}
return false
}.count
//Set the badge
content.badge = NSNumber(integerLiteral: UIApplication.shared.applicationIconBadgeNumber + earlierNotificationsCount + 1)
let trigger = UNTimeIntervalNotificationTrigger(timeInterval: timeInterval,
repeats: false)
let requestIdentifier = UUID().uuidString //You probably want to save these request identifiers if you want to remove the corresponding notifications later
let request = UNNotificationRequest(identifier: requestIdentifier,
content: content, trigger: trigger)
center.add(request, withCompletionHandler: { (error) in
// Handle error
})
}
})
}
(You may need to save the requests' identifiers (either in user defaults or core data if you'd like to update them, or even cancel them via removePendingNotificationRequests(withIdentifiers:))
You can call the above function like so:
sendNotification(title: "Meeting Reminder",
subtitle: "Staff Meeting in 20 minutes",
body: "Don't forget to bring coffee.",
timeInterval: 10)
Declare your view controller as a UNUserNotificationCenterDelegate:
class ViewController: UIViewController, UNUserNotificationCenterDelegate {
override func viewDidLoad() {
super.viewDidLoad()
UNUserNotificationCenter.current().delegate = self
}
//...
}
And to handle interacting with the notification, update the badge of the app, and the badge of the upcoming notifications:
func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: @escaping () -> Void) {
//UI updates are done in the main thread
DispatchQueue.main.async {
UIApplication.shared.applicationIconBadgeNumber -= 1
}
let center = UNUserNotificationCenter.current()
center.getPendingNotificationRequests(completionHandler: {requests in
//Update only the notifications that have userInfo["timeInterval"] set
let newRequests: [UNNotificationRequest] =
requests
.filter{ rq in
return rq.content.userInfo["timeInterval"] is Double?
}
.map { request in
let newContent: UNMutableNotificationContent = request.content.mutableCopy() as! UNMutableNotificationContent
newContent.badge = (Int(truncating: request.content.badge ?? 0) - 1) as NSNumber
let newRequest: UNNotificationRequest =
UNNotificationRequest(identifier: request.identifier,
content: newContent,
trigger: request.trigger)
return newRequest
}
newRequests.forEach { center.add($0, withCompletionHandler: { (error) in
// Handle error
})
}
})
completionHandler()
}
This updates the app badge by decreasing it when a notification is interacted with ie tapped. Plus it updates the content badge of the pending notifications. Adding a notification request with the same identifier just updates the pending notification.
To receive notifications in the foreground, and increase the app badge icon if the notification is not interacted with, implement this:
func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
DispatchQueue.main.async {
UIApplication.shared.applicationIconBadgeNumber += 1
}
completionHandler([.alert, .sound])
}
Here are some gifs:
1st: Receiving local notifications increases the app badge. Whereas interacting with a notification decreases the app badge.
2nd: Receiving local notifications when the app is killed (I used a trigger timeInterval of 15s in this).
3rd: Receiving notification whilst in the foreground increases the app badge unless the user interacts with it.
The complete class used in my test project looks like this:
import UIKit
import UserNotifications
class ViewController: UIViewController, UNUserNotificationCenterDelegate {
var bit = true
@IBAction func send(_ sender: UIButton) {
let time: TimeInterval = bit ? 8 : 4
bit.toggle()
sendNotification(title: "Meeting Reminder",
subtitle: "Staff Meeting in 20 minutes",
body: "Don't forget to bring coffee.",
timeInterval: time)
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
UNUserNotificationCenter.current().delegate = self
}
func sendNotification(title: String, subtitle: String, body: String, timeInterval: TimeInterval) {
let center = UNUserNotificationCenter.current()
center.getPendingNotificationRequests(completionHandler: { pendingNotificationRequests in
DispatchQueue.main.sync {
let content = UNMutableNotificationContent()
content.title = title
content.subtitle = subtitle
content.body = body
let firingDate = Date().timeIntervalSince1970 + timeInterval
content.userInfo = ["timeInterval": firingDate]
let earlierNotificationsCount: Int = pendingNotificationRequests.filter { request in
let userInfo = request.content.userInfo
if let time = userInfo["timeInterval"] as? Double {
if time < firingDate {
return true
} else {
let newContent: UNMutableNotificationContent = request.content.mutableCopy() as! UNMutableNotificationContent
newContent.badge = (Int(truncating: request.content.badge ?? 0) + 1) as NSNumber
let newRequest: UNNotificationRequest =
UNNotificationRequest(identifier: request.identifier,
content: newContent,
trigger: request.trigger)
center.add(newRequest, withCompletionHandler: { (error) in
// Handle error
})
return false
}
}
return false
}.count
content.badge = NSNumber(integerLiteral: UIApplication.shared.applicationIconBadgeNumber + earlierNotificationsCount + 1)
let trigger = UNTimeIntervalNotificationTrigger(timeInterval: timeInterval,
repeats: false)
let requestIdentifier = UUID().uuidString //You probably want to save these request identifiers if you want to remove the corresponding notifications later
let request = UNNotificationRequest(identifier: requestIdentifier,
content: content, trigger: trigger)
center.add(request, withCompletionHandler: { (error) in
// Handle error
})
}
})
}
func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
DispatchQueue.main.async {
UIApplication.shared.applicationIconBadgeNumber += 1
}
completionHandler([.alert, .sound])
}
func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: @escaping () -> Void) {
DispatchQueue.main.async {
UIApplication.shared.applicationIconBadgeNumber -= 1
}
let center = UNUserNotificationCenter.current()
center.getPendingNotificationRequests(completionHandler: {requests in
let newRequests: [UNNotificationRequest] =
requests
.filter{ rq in
return rq.content.userInfo["timeInterval"] is Double?
}
.map { request in
let newContent: UNMutableNotificationContent = request.content.mutableCopy() as! UNMutableNotificationContent
newContent.badge = (Int(truncating: request.content.badge ?? 0) - 1) as NSNumber
let newRequest: UNNotificationRequest =
UNNotificationRequest(identifier: request.identifier,
content: newContent,
trigger: request.trigger)
return newRequest
}
newRequests.forEach { center.add($0, withCompletionHandler: { (error) in
// Handle error
})
}
})
completionHandler()
}
}
center.getDeliveredNotifications? – Dispersal