How to store ios push notifications when the app is killed using swift

Question

I use my own server, use FCM to push notifications to the ios device, push notifications are successful, I also use the Realm database system to help me store the fcm push notifications, but the storage will only succeed in the following two cases. Case1: When the app is running.

Case2: The app is killed, or running in the background, when you click to push the banner notification.

But this is not my main intention. I know that when the app is killed, I can't handle the push notifications, so I want to be able to store the push notifications when the user opens the app.

Sorry, my English is not good. If there is something unclear, please let me know.

Realm class

class Order: Object {

    @objc dynamic var id = UUID().uuidString
    @objc dynamic var name = ""
    @objc dynamic var amount = ""
    @objc dynamic var createDate = Date()

    override static func primaryKey() -> String? {
        return "id"
    }

    let realm = try! Realm()
    let order: Order = Order()

AppDelegate.swift (when app runing store fcm message)

    func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {


        let userInfo = notification.request.content.userInfo //
        print("userInfo: \(userInfo)")

        guard
        let aps = userInfo[AnyHashable("aps")] as? NSDictionary,
        let alert = aps["alert"] as? NSDictionary,
        let body = alert["body"] as? String,
        let title = alert["title"] as? String
        else {
            // handle any error here
            return
        }
        print("Title: \(title) \nBody:\(body)")

        order.name = title
        order.amount = body
        try! realm.write {
            realm.add(order)
        }
        completionHandler([.badge, .sound, .alert])
    }

click to push the banner notification AppDelegate.swift (when app killed or on backgroung click to push the banner notification)

   func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: @escaping () -> Void) {  
        let userInfo = response.notification.request.content.userInfo

        print("userInfo: \(userInfo)")
        guard
            let aps = userInfo[AnyHashable("aps")] as? NSDictionary,
            let alert = aps["alert"] as? NSDictionary,
            let body = alert["body"] as? String,
            let title = alert["title"] as? String
            else {
                // handle any error here
                return
        }
        print("Title: \(title) \nBody:\(body)")

        order.name = title
        order.amount = body
        try! realm.write {
            realm.add(order)
        }
        completionHandler()
    }

Please have experienced people to help me, thank you very much.

Answer 1

You can store notifications into your database when your app is killed.

1. Add "Notification Service Extention" to your app.
2. Enable Background fetch/Remote notifications Capabilities into your app.
3. Enable "App Groups" into your app and enable the same with your "Notification Service Extention" .

4. Now you can access your database using "App Groups" , and can insert notifications into your database as soon as you receive the notification.

To access database using "App Group" use,

var fileMgr : FileManager!
let databasePathURL = fileMgr!.containerURL(forSecurityApplicationGroupIdentifier: "<APP_GROUPS_ID>")

From above code once you get the path for database, you can perform your insert operation into database. It would be your normal insert operation that you are performing.

Insert code for saving data in this file and in the method highlighted in below image.

For accessing your files into Extention follow the below image.

If you need any other help, Do let me know.