Implementing Background Capabilities on Swift - ios

I recently just finished an app that basically has an Observer for a Firebase Database, and when a certain attribute changes, sends a banner type notification.
The application works completely, but when I had the app in the background while using the phone, I realized that it doesn't run any code, or send notifications.
How can I implement both having the Observer listening for any changes from the Database in the background, as well as send a notification?
Here is the Notification Authorization Request function:
func requestNotificationAuthorization() {
let authOptions = UNAuthorizationOptions.init(arrayLiteral: .alert, .badge, .sound)
self.userNotificationCenter.requestAuthorization(options: authOptions) { (success, error) in
if let error = error {
print("Error: ", error)
}}}
The Notification Center function:
func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: #escaping () -> Void) {
completionHandler()
}
And the Send Notification function:
func sendNotification() {
// Create new notifcation content instance
let notificationContent = UNMutableNotificationContent()
// Add the content to the notification content
notificationContent.title = "P2P Tracker"
notificationContent.body = (PriceTimeDate ?? "")
print(notificationContent.body)
notificationContent.badge = NSNumber(value: 1)
// Add an attachment to the notification content
if let url = Bundle.main.url(forResource: "dune",
withExtension: "png") {
if let attachment = try? UNNotificationAttachment(identifier: "dune",
url: url,
options: nil) {
notificationContent.attachments = [attachment]
}
}
let trigger = UNTimeIntervalNotificationTrigger(timeInterval: 3,
repeats: false)
let request = UNNotificationRequest(identifier: "testNotification",
content: notificationContent,
trigger: trigger)
userNotificationCenter.add(request) { (error) in
if let error = error {
print("Notification Error: ", error)
}
}
}

Related

Sending local notifications in SWIFT

I added this code to my first ViewController
// Step-1 Ask permission from User
let center = UNUserNotificationCenter.current()
center.requestAuthorization(options: [.badge,.sound,.alert]) { granted, error in
if error == nil {
print("User permission is granted : \(granted)")
}
}
// Step-2 Create the notification content
let content = UNMutableNotificationContent()
content.title = "Hello"
content.body = "Welcome"
// Step-3 Create the notification trigger
let date = Date().addingTimeInterval(1)
let dateComponent = Calendar.current.dateComponents([.year,.month,.day,.hour,.minute,.second], from: date)
let trigger = UNCalendarNotificationTrigger(dateMatching: dateComponent, repeats: false)
// Step-4 Create a request
let uuid = UUID().uuidString
let request = UNNotificationRequest(identifier: uuid, content: content, trigger: trigger)
// Step-5 Register with Notification Center
center.add(request) { error in
but 5 seconds pass without any notification shown. What is wrong? Could somebody show me how to fix it??
The notification comes but when the app is foreground it won't show until you implement UNUserNotificationCenterDelegate method
UNUserNotificationCenter.current().delegate = self
func userNotificationCenter(_ center: UNUserNotificationCenter,
willPresent notification: UNNotification,
withCompletionHandler completionHandler: #escaping (UNNotificationPresentationOptions) -> Void) {
completionHandler([.sound,.alert])
}
Also set
let date = Date().addingTimeInterval(5)
to give it some time until app hits so you can test it after clicking home button
import UIKit
class ViewController: UIViewController , UNUserNotificationCenterDelegate {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
let center = UNUserNotificationCenter.current()
center.delegate = self
center.requestAuthorization(options: [.badge,.sound,.alert]) { granted, error in
if error == nil {
print("User permission is granted : \(granted)")
}
}
// Step-2 Create the notification content
let content = UNMutableNotificationContent()
content.title = "Hello"
content.body = "Welcome"
// Step-3 Create the notification trigger
let date = Date().addingTimeInterval(5)
let dateComponent = Calendar.current.dateComponents([.year,.month,.day,.hour,.minute,.second], from: date)
let trigger = UNCalendarNotificationTrigger(dateMatching: dateComponent, repeats: false)
// Step-4 Create a request
let uuid = UUID().uuidString
let request = UNNotificationRequest(identifier: uuid, content: content, trigger: trigger)
// Step-5 Register with Notification Center
center.add(request) { error in
}
}
func userNotificationCenter(_ center: UNUserNotificationCenter,
willPresent notification: UNNotification,
withCompletionHandler completionHandler: #escaping (UNNotificationPresentationOptions) -> Void) {
completionHandler([.sound,.alert])
}
}

Schedule Local notification on Remote Notification

In our project, we want to changed a title and body of Remote Notification . In that we generate a Local Notification and Display a local notification with changed a title and body and hide push Notification. But in that while App is in Background and kill State it will display a Remote a Notification instead of Local Notification. But we want to display a Local Notification instead of push in Will present Notification. how to do this ?
func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: #escaping (UNNotificationPresentationOptions) -> Swift.Void) {
if notification.request.identifier != "local_notification1"{
self.isAdded = false
}
let name = (ContactsManager.shared.getContacName(withPhoneNumber:notification.request.content.title) != nil) ? ContactsManager.shared.getContacName(withPhoneNumber:notification.request.content.title) :
notification.request.content.title
let notificationContent = UNMutableNotificationContent()
// notificationContent.userInfo = notification.request.content.userInfo
notificationContent.body = notification.request.content.body
notificationContent.title = name!
debugPrint("name title is %# ", name)
debugPrint("notificationContent title is %# ", notificationContent.title)
notificationContent.sound = .default
let notificationTrigger = UNTimeIntervalNotificationTrigger(timeInterval: 0.1, repeats: false)
let notificationRequest = UNNotificationRequest(identifier: "local_notification1", content: notificationContent, trigger: notificationTrigger)
if !isAdded {
UNUserNotificationCenter.current().add(notificationRequest) { (error) in
if let error = error {
debugPrint("Unable to Add Notification Request (\(error), \(error.localizedDescription))")
}else {
print("is Shown")
}
self.isAdded = true
}
completionHandler([])
}
completionHandler([.alert,.sound])
}
}
You can modify content of remote notification with help of UNNotificationServiceExtension
First override didReceive(_ request: UNNotificationRequest, withContentHandler contentHandler: #escaping (UNNotificationContent) -> Void) {
Modify content and.
Return updated content in contentHandler
Note: Required iOS 10+

Displaying local notifications when app starts up in iOS

In my app I want to give a notification for an event when the user first enters the app. I have the notifications set up in another viewController handling the calendar that holds the events:
//setup calendar notifications
func createNotification(){
let content = UNMutableNotificationContent()
content.title = "Event"
content.subtitle = eventNameArray[0]
content.body = descriptionsArray[0]
content.sound = UNNotificationSound.default()
let trigger = UNTimeIntervalNotificationTrigger(timeInterval: 3.0, repeats: false)
let request = UNNotificationRequest(identifier: "notification", content: content, trigger: trigger)
UNUserNotificationCenter.current().add(request){
(error) in
print(error as Any)
}
}
This notification only triggers in when the user goes to the calendar page.
How do I display this notification when the user boots up the app? Do I need to make changes to the AppDelegate?
EDIT: Following a this tutorial (https://www.youtube.com/watch?v=cx2B8P84tS4) I implemented a new class to push the notifications:
import UIKit
import UserNotifications
class NotificationPublisher: NSObject {
func sendNotification(title: String,
subtitle: String,
body: String,
badge: Int?,
delayInterval: Int?){
let notificationContent = UNMutableNotificationContent()
notificationContent.title = title
notificationContent.subtitle = subtitle
notificationContent.body = body
var delayTimeTrigger: UNTimeIntervalNotificationTrigger?
if let delayInterval = delayInterval {
delayTimeTrigger = UNTimeIntervalNotificationTrigger(timeInterval: TimeInterval(delayInterval), repeats: false)
}
if let badge = badge {
var currentBadgeCount = UIApplication.shared.applicationIconBadgeNumber
currentBadgeCount += badge
notificationContent.badge = NSNumber(integerLiteral: currentBadgeCount)
}
notificationContent.sound = UNNotificationSound.default()
UNUserNotificationCenter.current().delegate = self
let request = UNNotificationRequest(identifier: "TestLocalNotification", content: notificationContent, trigger: delayTimeTrigger)
UNUserNotificationCenter.current().add(request) {
error in
if let error = error {
print(error.localizedDescription)
}
}
}
}
extension NotificationPublisher: UNUserNotificationCenterDelegate {
func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: #escaping (UNNotificationPresentationOptions) -> Void) {
completionHandler([.alert, .sound, .badge])
}
func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: #escaping () -> Void) {
let identifier = response.actionIdentifier
switch identifier {
case UNNotificationDismissActionIdentifier:
print("Notification dismissed")
completionHandler()
case UNNotificationDefaultActionIdentifier:
print("User opened app from notification ")
default:
print("Default case was called")
completionHandler()
}
}
}
Then inside the viewController of the startup page I did this:
class ViewController: UIViewController{
private let notificationPublisher = NotificationPublisher()
private let calendarEvents = CalendarController()
override func viewDidLoad() {
super.viewDidLoad()
print("Events to show in notification: ", calendarEvents.descriptionsArray)
notificationPublisher.sendNotification(title: "Hey", subtitle: "Testing", body: "Is this working?", badge: 1, delayInterval: nil )
}
}
The app shows the notification on startup but I cannot display anything inside the calendarEvents.descriptionsArray as it is empty. How do I make it so the array is filled with data from a server so that the notification can display the event?
You can do simply the same in AppDelegate class on method applicationDidFinishLaunchingWithOptions
you may want to save a flag to NSUSerDefaults to indicate whether it is the very first launch of the app or not and act accordingly (display local notification)

Local Notifications swift 3

I am trying to send a notification on a button click. This is the code in my viewController:
#IBAction func getNotificationButtonPressed(_ sender: Any) {
let content = UNMutableNotificationContent()
content.title = "Title"
content.body = "Body"
content.categoryIdentifier = "ident"
content.sound = UNNotificationSound.default()
let trigger = UNTimeIntervalNotificationTrigger(timeInterval: 0.1, repeats: false)
let request = UNNotificationRequest(identifier: "ident", content: content, trigger: trigger)
let center = UNUserNotificationCenter.current()
center.add(request) { (error : Error?) in
if let theError = error {
print(theError.localizedDescription)
} else {
print ("success")
}
}
}
also in AppDelegate I have requested permission to use Notifications:
let center = UNUserNotificationCenter.current()
center.requestAuthorization(options:[.badge, .alert, .sound]) { (granted, error) in
// Enable or disable features based on authorization.
}
application.registerForRemoteNotifications()
P.S. I have imported
import UserNotifications
in both AppDelegate and the custom ViewController.
When you create notification at that check
if #available(iOS 10.0, *) {
let content = UNMutableNotificationContent()
content.title = "Intro to Notifications"
content.subtitle = "Lets code,Talk is cheap"
content.body = "Sample code from WWDC"
content.sound = UNNotificationSound.default()
// Deliver the notification in five seconds.
let trigger = UNTimeIntervalNotificationTrigger.init(timeInterval: 5.0, repeats: false)
let request = UNNotificationRequest(identifier:requestIdentifier, content: content, trigger: trigger)
UNUserNotificationCenter.current().delegate = self
UNUserNotificationCenter.current().add(request){(error) in
if (error != nil){
print(error?.localizedDescription)
}
}
}
Implement this delegates method UNUserNotification for Notification being triggered.
#available(iOS 10.0, *)
func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: #escaping () -> Void) {
print("Tapped in notification")
}
//This is key callback to present notification while the app is in foreground
#available(iOS 10.0, *)
func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: #escaping (UNNotificationPresentationOptions) -> Void) {
print("Notification being triggered")
//You can either present alert ,sound or increase badge while the app is in foreground too with ios 10
//to distinguish between notifications
if notification.request.identifier == requestIdentifier{
completionHandler( [.alert,.sound,.badge])
}
}
Happy coding.

Local Notifications make sound but do not display (Swift)

I am trying to create a local notification for my app using Apple's UNUserNotificationCenter.
Here is my code:
let center = UNUserNotificationCenter.current()
let content = UNMutableNotificationContent()
content.title = task.name
content.body = task.notes
content.sound = UNNotificationSound.default()
let trigger = UNTimeIntervalNotificationTrigger(timeInterval: 5, repeats: false)
let request = UNNotificationRequest(identifier: task.UUID, content: content, trigger: trigger)
center.add(request) { (error:Error?) in
if let theError = error {
print("Notification scheduling error: \(error)")
}else{
print("Notification was scheduled successfully")
}
}
Access Request:
let center = UNUserNotificationCenter.current()
//request notification access
let options: UNAuthorizationOptions = [.alert, .sound]
center.requestAuthorization(options: options) { (granted, error) in
if !granted {
print("Notification access was denied")
}
}
After 5 seconds the app makes the Default sound but does not show the alert content. I am trying both with the app in the foreground and in the background.
I had the same problem.
If your content body is blank ie(content.body == "") then you won't get a notification even if you do have a title.
So the solution is to make sure that your content body is not an empty string.
Add this Protocoal UNUserNotificationCenterDelegate.
and add this delegate into your controller. and dont forget to set delegate.
UNUserNotificationCenter.current().delegate = self
func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: #escaping (UNNotificationPresentationOptions) -> Void) {
print("Notification being triggered")
//You can either present alert ,sound or increase badge while the app is in foreground too with ios 10
//to distinguish between notifications
if notification.request.identifier == "yourrequestid"{
completionHandler( [.alert,.sound,.badge])
}
}
Add this code into didFinishLaunchingWithOption in AppDelegate.swift file
let center = UNUserNotificationCenter.current()
center.requestAuthorization(options: [.alert, .sound])
{ (granted, error) in
// Enable or disable features based on authorization.
}

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