Corebluetooth to fetch device names using Swift - ios

Question

I'm using CoreBluetooth framework in my iOS application to scan and connect to other bluetooth devices. I'm able to scan successfully for devices using below code:
var centralManager: CBCentralManager?
var peripherals = [CBPeripheral]()
centralManager = CBCentralManager(delegate: self, queue: DispatchQueue.main)
In the CBCentralManagerDelegate, I implemented below code:
extension ViewController: CBCentralManagerDelegate {
func centralManagerDidUpdateState(_ central: CBCentralManager) {
if (central.state == .poweredOn){
self.centralManager?.scanForPeripherals(withServices: nil, options: nil)
}
}
func centralManager(_ central: CBCentralManager, didDiscover peripheral: CBPeripheral, advertisementData: [String : Any], rssi RSSI: NSNumber) {
if !peripherals.contains(peripheral) {
let localName = advertisementData[CBAdvertisementDataLocalNameKey]
print("\(String(describing: localName))" )
peripherals.append(peripheral)
tableView.reloadData()
}
}
}
From above code localName is always nil. Am I missing any code?
To add more info,
When I am scanning for bluetooth devices in my Mac, I'm able to see the names of the devices. But when I am scanning for bluetooth devices on my iPhone, none of them are listed.
I cross checked and made sure that I enabled blue tooth on 4 more devices with me (iPad, 2 Android Phones and 1 Android TV)

Answer 1

Swift with core bluetooth library:
func centralManager(_ central: CBCentralManager, didDiscover peripheral: CBPeripheral, advertisementData: [String : Any], rssi RSSI: NSNumber){
let peripheralLocalName_advertisement = ((advertisementData as NSDictionary).value(forKey: "kCBAdvDataLocalName")) as? String
if (((advertisementData as NSDictionary).value(forKey: "kCBAdvDataLocalName")) != nil)
print(peripheralLocalName_advertisement)//peripheral name from advertismentData
print(peripheral.name)//peripheral name from peripheralData
peripherals.append(peripheral)
arrayPeripheral.append(advertisementData)
}
}

Answer 2

I changed in your code only source of name - instead of:
let localName = advertisementData[CBAdvertisementDataLocalNameKey]
I use:
let localName = peripheral.name
and now I see name of BLE devices around me.

Answer 3

I changed in your code only source of name - instead of:
let localName = advertisementData[CBAdvertisementDataLocalNameKey]
I use:
let localName = peripheral.name
and now I see name of BLE devices around me.

Answer 4

The didDiscoverPeripheral callback unfortunately can return nil for CBPeripheral names and also the advertisementData's local name for the very first callback your app gets after you start a scan.
If you know that the peripheral that you're working with will contain a local name in the Bluetooth advertisement packet, you can choose to ignore the first callback that contains a nil name.
// In didDiscoverPeripheral
guard let peripheralName = peripheral.name else { return }
print("Did discover peripheral: \(peripheralName), RSSI: \(RSSI)")