Updating code to Swift 3 - ios

Question

I am a beginner to programming with swift and programming in general. I am currently working on an app which allows one phone to send a message (peripheral) to another which will receive the message (central). I have taken most of the code from an app built using swift 2 and have tweaked it slightly to remove any errors. As a result, my code is a jumble of swift 2/3 (or so I have been told). I am not sure how to update this code fully to swift 3 which I need someones help to do. I believe it is the IBActions and delegates that are outdated but I am completely clueless on how to amend it.
I have tried running the app and it runs successfully but when I press any of the buttons nothing happens as far as I can tell. I have a basic understanding of what my code does and what each function is there for but I find myself stuck on what to do for it to work. If anyone has experience working with Bluetooth via swift and can see what I am doing wrong or perhaps if I haven't included something important. I am led to believe the issue is that all the code has not been updated to swift 3 but I can't be sure. I have read the Apple documentation for Core bluetooth.
PS: I know this question is very vague as I am unsure on what part of my code I need to fix so it is very difficult to make it specific to a single issue. Sorry!
import UIKit
import CoreBluetooth
class ViewController: UIViewController, CBPeripheralManagerDelegate, CBCentralManagerDelegate, CBPeripheralDelegate {
let messageUUID = CBUUID(string: "053D6600-821E-46A7-AC25-43A81D948E8B")
let inputUUID = CBUUID(string: "49A79D26-5323-4374-81EA-29B099AF85C8")
let otherUUID = CBUUID(string: "053D6600-821E-46A7-AC25-43A81D948E87")
var peripheralManager: CBPeripheralManager!
var characteritic: CBMutableCharacteristic!
var getDataPeripheralCharacteristic: CBMutableCharacteristic!
var service: CBMutableService!
var outputData:String = ""
var centralManager: CBCentralManager!
var connectingPeripheral: CBPeripheral?
var centralWriteCharacteristic: CBCharacteristic!
#IBOutlet var inputLabel: UITextField!
#IBOutlet weak var outputLabel: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
}
#IBAction func centralMode(_ sender: UIButton) {
centralManager = CBCentralManager(delegate: self, queue: nil)
peripheralManager = nil
}
#IBAction func peripheralMode(_ sender: UIButton) {
peripheralManager = CBPeripheralManager(delegate: self, queue: nil)
centralManager = nil
}
#IBAction func sendData(_ sender: UIButton) {
if (peripheralManager != nil) {
let passed = peripheralManager.updateValue(inputLabel.text!.data(using: String.Encoding.utf8)!, for: characteritic!, onSubscribedCentrals: nil)
if passed == false {
print("error couldn't send data")
}
}
if (centralManager != nil) {
if (connectingPeripheral != nil) {
connectingPeripheral?.writeValue(inputLabel.text!.data(using: String.Encoding.utf8)!, for: centralWriteCharacteristic, type: CBCharacteristicWriteType.withResponse)
}
}
}
func peripheralManagerDidUpdateState(_ peripheral: CBPeripheralManager) {
if (peripheral.state == .poweredOn) {
characteritic = CBMutableCharacteristic(type: messageUUID, properties: CBCharacteristicProperties.notify, value: nil, permissions: CBAttributePermissions.readable)
getDataPeripheralCharacteristic = CBMutableCharacteristic(type: inputUUID, properties:
CBCharacteristicProperties.write, value: nil, permissions: CBAttributePermissions.writeable)
service = CBMutableService(type: otherUUID, primary: true)
service.characteristics = [characteritic!, getDataPeripheralCharacteristic!]
peripheralManager!.add(service)
}
}
func peripheralManager(peripheral: CBPeripheralManager, didAddService service: CBService, error: NSError?) {
peripheral.stopAdvertising()
let identifier = Bundle.main.bundleIdentifier!
let manufacturerData = identifier.data(using: String.Encoding.utf8, allowLossyConversion: false)
let dataToBeAdvertised:[String: Any] = [
CBAdvertisementDataLocalNameKey : "Sample peripheral",
CBAdvertisementDataManufacturerDataKey : manufacturerData as Any,
CBAdvertisementDataServiceUUIDsKey : [messageUUID, inputUUID],
]
peripheralManager.startAdvertising(dataToBeAdvertised)
}
func peripheralManager(peripheral: CBPeripheralManager, didReceiveWriteRequests requests: [CBATTRequest]) {
for request in requests {
if (request.characteristic.uuid.uuidString == inputUUID.uuidString) {
outputData = String(data: request.value!, encoding: String.Encoding.utf8)!
outputLabel.text = outputData
}
}
}
func peripheralManager(peripheral: CBPeripheralManager, didReceiveReadRequest request: CBATTRequest) {
}
func peripheralManager(peripheral: CBPeripheralManager, central: CBCentral, didSubscribeToCharacteristic characteristic: CBCharacteristic) {
outputLabel.text = "Press send message"
print("Now connected")
}
func centralManagerDidUpdateState(_ central: CBCentralManager) {
if central.state == .poweredOn {
centralManager.scanForPeripherals(withServices: nil, options: nil)
//search for peripheral device
}
}
//when peripheral is discovered, this method is called
private func centralManager(central: CBCentralManager, didDiscoverPeripheral peripheral: CBPeripheral, advertisementData: [String : AnyObject], RSSI: NSNumber) {
self.centralManager.stopScan();
self.connectingPeripheral = peripheral;
peripheral.delegate = self;
centralManager.connect(peripheral, options: nil)
}
//if connection request from central is succesfull, this method is called
func centralManager(central: CBCentralManager, didConnectPeripheral peripheral: CBPeripheral) {
peripheral.delegate = self;
peripheral.discoverServices(nil)
}
//if central discovers services, this method is called
private func peripheral(peripheral: CBPeripheral, didDiscoverServices error: NSError?) {
for service: CBService in peripheral.services! {
peripheral.discoverCharacteristics(nil, for: service)
}
}
private func peripheral(peripheral: CBPeripheral, didDiscoverCharacteristicsForService service: CBService, error: NSError?) {
if (service.uuid.uuidString == otherUUID.uuidString) {
guard let characteristics = service.characteristics else {
return
}
for characteristic in characteristics {
if characteristic.uuid.uuidString == messageUUID.uuidString {
peripheral.setNotifyValue(true, for: characteristic)
} else if characteristic.uuid.uuidString == inputUUID.uuidString {
centralWriteCharacteristic = characteristic
}
}
}
}
private func peripheral(peripheral: CBPeripheral, didUpdateValueForCharacteristic characteristic: CBCharacteristic, error: NSError?) {
if error != nil {
print("Error reading characteristics");
}
if (characteristic.uuid == messageUUID) {
outputData = String(data: characteristic.value!, encoding: String.Encoding.utf8)!
print(outputData)
outputLabel.text = outputData
}
}
}

Answer 1

If the issue is because of swift 2/3 mismatch. Try upgrading your code to swift3.
Go to Xcode-edit-convert- to current swift syntax.
This will lead to few build errors, identify them and fix them.
Make your sure if you have any pod or cart file , do not forget to upgrade them as well.
Hopefully this should resolve your issue.