How to get notify when advertisementData changed when app is in background?

Question

I want to get notified when something happened at the BLE device. If BLE device passes some data/Command to the app, then in-app the advertisementData not changed. But the same thing we can do with android it's working perfectly. I want to implement functionality like when advertisementData changed I want to get notify. Please help me to implement this. Below is my AppDelegate.swift class.

private var centralManager : CBCentralManager!

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {

    centralManager = CBCentralManager(delegate: self, queue: nil, options: nil)

    return true
}

func applicationWillEnterForeground(_ application: UIApplication) {

    print("entering foreground...")
}

func applicationDidEnterBackground(_ application: UIApplication) {
    print("entered background...")

    centralManager = CBCentralManager(delegate: self, queue: nil, options: nil)
}


func centralManagerDidUpdateState(_ central: CBCentralManager) {
    if central.state == .poweredOn {
        print("Bluetooth is On")

        let kTrackStandardDeviceInfoServiceUUID  = CBUUID(string: "180A")

        let dictionaryOfOptions = [CBCentralManagerScanOptionAllowDuplicatesKey : true]
        let arrayOfServices: [CBUUID] = [kTrackStandardDeviceInfoServiceUUID]

        centralManager.scanForPeripherals(withServices: arrayOfServices, options: dictionaryOfOptions)
    } else {
        print(central.state)
    }
}

func centralManager(_ central: CBCentralManager, didDiscover peripheral: CBPeripheral, advertisementData: [String : Any], rssi RSSI: NSNumber) {

    print("\nName   : \(peripheral.name ?? "(No name)")")
    print("RSSI   : \(RSSI)")

    let name = peripheral.name ?? ""
    if name.contains("ETGuardian") {

        let DetailData = advertisementData["kCBAdvDataManufacturerData"]
        let DiscoveredData = String(describing: DetailData)

        print(DiscoveredData)

        for ad in advertisementData {
            print("AD Data: \(ad)")
        }
    }
}

Answer 1

For having the application can work in the background, you need to implement some background services in your apps.

Usually, background service is location fetch. Please note that background service will make your app draining the battery faster

To implement the background service, Click your project, Signing & Capabilities, Background Modes, enable the BLE features.