I am writing a very, very simple TCP socket app that sends and receives data from a server; my app uses delegates; most of the code I found from online but none of the event handlers for the streams are working; any ideas on why the following method is never being called?
UPDATE: this question has been answered here:
Non-responsive stream delegate in Swift
However, the problem that I am facing is how do I flush the output stream after the buffer is full? I would like send data in real time to my server, but I am getting a "broken pipe" from stream output error
/**
NSStream Delegate Method where we handle errors, read and write data from input and output streams
:param: stream NStream that called delegate method
:param: eventCode Event Code
*/
final func stream(stream: Stream, handleEvent eventCode: Stream.Event) {
switch eventCode {
case Stream.Event.endEncountered:
endEncountered(stream: stream)
case Stream.Event.errorOccurred:
print("[SCKT]: ErrorOccurred: \(stream.streamError?.localizedDescription)")
case Stream.Event.openCompleted:
print("open completed")
openCompleted(stream: stream)
case Stream.Event.hasBytesAvailable:
handleIncommingStream(stream: stream)
case Stream.Event.hasSpaceAvailable:
print("space available")
writeToStream()
default:
print("default!")
}
}
UIViewController
import Darwin
import Foundation
import UIKit
import Dispatch
class ViewController: UIViewController {
#IBOutlet private weak var joystickMove: Joystick!
#IBOutlet private weak var joystickRotate: Joystick!
private var joystick = Joystick()
private var contour = Contours()
private var contour_index: Int = 0
private var ip_address = "000.000.00.0" as CFString
private var port: Int = 0000
private var control_socket: Socket
// private var control_socket: Socket = Socket()
private var toast_label: UILabel = UILabel()
// let dataProcessingQueue = DispatchQueue.main
// convenience init() {
// self.control_socket = Socket()
// }
// init(coder aDecoder: NSCoder!) {
// super.init(coder: aDecoder)
// }
// init(imageURL: NSURL?) {
// self.control_socket = Socket()
// self.control_socket.open(host: self.ip_address as String!, port: self.port)
// super.init(nibName: nil, bundle: nil)
// }
// required init?(coder aDecoder: NSCoder) {
// fatalError("init(coder:) has not been implemented")
// }
required init(coder aDecoder: NSCoder) {
print("here!")
self.control_socket = Socket()
// self.control_socket.open(host: self.ip_address as String!, port: self.port)
print("here(2)!")
super.init(coder: aDecoder)!
}
override func viewDidLoad() {
super.viewDidLoad()
self.control_socket.open(host: self.ip_address as String!, port: self.port)
createJoystick()
createContours()
createViewsButton()
recvLidarData()
}
private func requestIsComplete() -> Bool {
// This function should find out if all expected data was received and return 'true' if it did.
return true
}
private func processData(data: Data) {
// This function should do something with the received data
}
private func recvLidarData() {
let concurrentQueue = DispatchQueue(label: "queuename", attributes: .concurrent)
concurrentQueue.async {
// recieve the data here!
}
}
private func createToast() {
self.toast_label = UILabel(frame: CGRect(x: self.view.frame.size.width/2 - 150, y: self.view.frame.size.height-100, width: 300, height: 35))
self.toast_label.backgroundColor = UIColor.black
self.toast_label.textColor = UIColor.white
self.toast_label.textAlignment = NSTextAlignment.center;
self.view.addSubview(self.toast_label)
self.toast_label.text = "Could not connect to server"
self.toast_label.alpha = 1.0
self.toast_label.layer.cornerRadius = 10;
self.toast_label.clipsToBounds = true
UIView.animate(withDuration: 4.0, delay: 0.1, options: UIViewAnimationOptions.curveEaseOut, animations: {
self.toast_label.alpha = 0.0
})
}
private func createJoystick() {
let n: CGFloat = 100.0
let x: CGFloat = (UIScreen.main.bounds.width/2) - (n/2.0)
let y: CGFloat = UIScreen.main.bounds.height - (UIScreen.main.bounds.height/4.0)
self.joystick.frame = CGRect(x: x, y: y, width: n, height: n)
self.joystick.backgroundColor = UIColor.clear
self.joystick.substrateColor = UIColor.lightGray
self.joystick.substrateBorderColor = UIColor.gray
self.joystick.substrateBorderWidth = 1.0
self.joystick.stickSize = CGSize(width: 50.0, height: 50.0)
self.joystick.stickColor = UIColor.darkGray
self.joystick.stickBorderColor = UIColor.black
self.joystick.stickBorderWidth = 2.0
self.joystick.fade = 0.5
self.joystick.ip_address = self.ip_address
self.joystick.port = self.port
var packet = ""
DispatchQueue.global(qos: .userInitiated).async { // do some task
// self.control_socket = Socket()
// self.control_socket.open(host: self.ip_address as String!, port: self.port)
self.joystick.trackingHandler = { (data) -> () in
var power = sqrt(pow(Double(data.velocity.x), 2.0) + pow(Double(data.velocity.y), 2.0))
let theta = atan2(Double(-data.velocity.y), Double(data.velocity.x))
let degrees = theta * (180.0 / M_PI)
power = power/1.2
if degrees >= 55 && degrees <= 125 { // move forward
packet = "\(1) \(1) \(power) \(power)"
} else if degrees >= -125 && degrees <= -55 { // move backwards
packet = "\(-1) \(-1) \(power) \(power)"
} else if degrees >= -55 && degrees <= 55 { // turn right
packet = "\(1) \(-1) \(power) \(power)"
} else { // turn left
packet = "\(-1) \(1) \(power) \(power)"
}
}
print("packet: \(packet)")
self.control_socket.send(message: packet)
print("sent")
}
view.addSubview(joystick)
}
private func createContours() {
let n: CGFloat = 350.0
let x: CGFloat = (UIScreen.main.bounds.width/2.0) - (n/2.0)
let y: CGFloat = UIScreen.main.bounds.height - (UIScreen.main.bounds.height/4.0) - n - 100.0
self.contour.frame = CGRect(x: x, y: y, width: n, height: n)
self.contour.backgroundColor = UIColor.clear
view.addSubview(self.contour)
}
private func createViewsButton() {
let width: CGFloat = 150.0
let height: CGFloat = 75.0
let x: CGFloat = (UIScreen.main.bounds.width/2.0) - (width/2.0)
let y: CGFloat = UIScreen.main.bounds.height - (UIScreen.main.bounds.height/4.0) - width
let button: UIButton = UIButton(frame: CGRect(x: x, y: y, width: width, height: height))
button.backgroundColor = UIColor.blue
button.setTitle("Contour Views", for: .normal)
button.addTarget(self, action: #selector(self.buttonAction), for: .touchUpInside)
button.tag = 1
view.addSubview(button)
}
#objc private func buttonAction(sender: UIButton!) {
var btnsendtag: UIButton = sender
if btnsendtag.tag == 1 {
self.contour_index = (self.contour_index + 1) % 2
switch self.contour_index {
case 0:
for index in 0...356 {
if self.contour.distx[index] != -1 && self.contour.disty[index] != -1 {
self.contour.circles[index].alpha = 0
}
}
case 1:
for index in 0...356 {
if self.contour.distx[index] != -1 && self.contour.disty[index] != -1 {
self.contour.circles[index].alpha = 1
}
}
default:
for index in 0...356 {
if self.contour.distx[index] != -1 && self.contour.disty[index] != -1 {
self.contour.circles[index].alpha = 1
UIColor.cyan.setFill()
self.contour.lines[index].fill()
self.contour.lines[index].stroke()
}
}
}
}
}
override func viewDidAppear(_ animated: Bool) {
}
public func delayWithSeconds(_ seconds: Double, completion: #escaping () -> ()) {
DispatchQueue.main.asyncAfter(deadline: .now() + seconds) {
completion()
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func viewWillDisappear(_ animated: Bool) {
}
}
Socket class
import UIKit
import Foundation
#objc protocol SocketStreamDelegate{
func socketDidConnect(stream:Stream)
#objc optional func socketDidDisconnet(stream:Stream, message:String)
#objc optional func socketDidReceiveMessage(stream:Stream, message:String)
#objc optional func socketDidEndConnection()
}
class Socket: NSObject, StreamDelegate {
var delegate:SocketStreamDelegate?
private let bufferSize = 1024
private var _host:String?
private var _port:Int?
private var _messagesQueue:Array<String> = [String]()
private var _streamHasSpace:Bool = false
private var inputStream: InputStream?
private var outputStream: OutputStream?
var isClosed = false
var isOpen = false
var host:String?{
get{
return self._host
}
}
var port:Int?{
get{
return self._port
}
}
deinit{
if let inputStr = self.inputStream{
inputStr.close()
inputStr.remove(from: .main, forMode: RunLoopMode.defaultRunLoopMode)
}
if let outputStr = self.outputStream{
outputStr.close()
outputStr.remove(from: .main, forMode: RunLoopMode.defaultRunLoopMode)
}
}
/**
Opens streaming for both reading and writing, error will be thrown if you try to send a message and streaming hasn't been opened
:param: host String with host portion
:param: port Port
*/
final func open(host:String!, port:Int!){
self._host = host
self._port = port
var inStreamUnmanaged:Unmanaged<CFReadStream>?
var outStreamUnmanaged:Unmanaged<CFWriteStream>?
CFStreamCreatePairWithSocketToHost(nil, host as CFString!, UInt32(port), &inStreamUnmanaged, &outStreamUnmanaged)
inputStream = inStreamUnmanaged?.takeRetainedValue()
outputStream = outStreamUnmanaged?.takeRetainedValue()
if inputStream != nil && outputStream != nil {
inputStream!.delegate = self
outputStream!.delegate = self
// var myloop = RunLoop.current
// inputStream!.schedule(in: myloop, forMode: RunLoopMode.defaultRunLoopMode)
// outputStream!.schedule(in: myloop, forMode: RunLoopMode.defaultRunLoopMode)
inputStream!.schedule(in: .main, forMode: RunLoopMode.defaultRunLoopMode)
outputStream!.schedule(in: .main, forMode: RunLoopMode.defaultRunLoopMode)
print("[SCKT]: Open Stream")
self._messagesQueue = Array()
inputStream!.open()
outputStream!.open()
// myloop.run()
print("Run")
} else {
print("[SCKT]: Failed Getting Streams")
}
}
final func close(){
if let inputStr = self.inputStream {
inputStr.delegate = nil
inputStr.close()
inputStr.remove(from: .main, forMode: RunLoopMode.defaultRunLoopMode)
}
if let outputStr = self.outputStream {
outputStr.delegate = nil
outputStr.close()
outputStr.remove(from: .main, forMode: RunLoopMode.defaultRunLoopMode)
}
isClosed = true
}
/**
NSStream Delegate Method where we handle errors, read and write data from input and output streams
:param: stream NStream that called delegate method
:param: eventCode Event Code
*/
final func stream(stream: Stream, handleEvent eventCode: Stream.Event) {
switch eventCode {
case Stream.Event.endEncountered:
endEncountered(stream: stream)
case Stream.Event.errorOccurred:
print("[SCKT]: ErrorOccurred: \(stream.streamError?.localizedDescription)")
case Stream.Event.openCompleted:
print("open completed")
openCompleted(stream: stream)
case Stream.Event.hasBytesAvailable:
handleIncommingStream(stream: stream)
case Stream.Event.hasSpaceAvailable:
print("space available")
writeToStream()
default:
print("default!")
}
}
final func endEncountered(stream: Stream) {
}
final func openCompleted(stream: Stream){
if(self.inputStream!.streamStatus == .open && self.outputStream!.streamStatus == .open) {
let justAOneTimeThing: () = {
self.isOpen = true
self.delegate!.socketDidConnect(stream: stream)
}()
}
}
/**
Reads bytes asynchronously from incomming stream and calls delegate method socketDidReceiveMessage
:param: stream An NSInputStream
*/
final func handleIncommingStream(stream: Stream) {
if stream is InputStream {
var buffer = [UInt8](repeating: 0, count: bufferSize)
DispatchQueue.global(qos: .userInitiated).async {
let len = self.inputStream?.read(&buffer, maxLength: buffer.count)
if len! >= 0 {
if let output = NSString(bytes: &buffer, length: len!, encoding: String.Encoding.utf8.rawValue) {
self.delegate?.socketDidReceiveMessage!(stream: stream, message: output as String)
}
} else {
// Handle error
}
}
} else {
print("[SCKT]: \(#function) : Incorrect stream received")
}
}
/**
If messages exist in _messagesQueue it will remove and it and send it, if there is an error
it will return the message to the queue
*/
final func writeToStream() {
if _messagesQueue.count > 0 && self.outputStream!.hasSpaceAvailable {
DispatchQueue.global(qos: .userInitiated).async {
let message = self._messagesQueue.removeLast()
let buff = [UInt8](message.utf8)
if self.outputStream!.write(buff, maxLength: buff.count) == -1 {
self._messagesQueue.append(message)
}
}
}
}
final func send(message:String){
_messagesQueue.insert(message, at: 0)
writeToStream()
}
}
Maybe your stream function prototype is incorrect. Your prototype is
final func stream(stream: Stream, handleEvent eventCode: Stream.Event)
Try this:
func stream(_ aStream: Stream, handle eventCode: Stream.Event)
in your Socket class
When I try to check for an internet connection on my iPhone I get a bunch of errors. Can anyone help me to fix this?
The code:
import Foundation
import SystemConfiguration
public class Reachability {
class func isConnectedToNetwork() -> Bool {
var zeroAddress = sockaddr_in()
zeroAddress.sin_len = UInt8(sizeofValue(zeroAddress))
zeroAddress.sin_family = sa_family_t(AF_INET)
let defaultRouteReachability = withUnsafePointer(&zeroAddress) {
SCNetworkReachabilityCreateWithAddress(nil, UnsafePointer($0))
}
var flags: SCNetworkReachabilityFlags = 0
if SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags) == 0 {
return false
}
let isReachable = (flags & UInt32(kSCNetworkFlagsReachable)) != 0
let needsConnection = (flags & UInt32(kSCNetworkFlagsConnectionRequired)) != 0
return (isReachable && !needsConnection) ? true : false
}
}
The errors with the code:
If it is unreadable, error 1 says:
'Int' is not convertible to 'SCNetworkReachabilityFlags'
Error 2 & 3:
Could not find an overload for 'init' that accepts the supplied arguments
To solve the 4G issue mentioned in the comments I have used #AshleyMills reachability implementation as a reference and rewritten Reachability for Swift 3.1:
updated: Xcode 10.1 • Swift 4 or later
Reachability.swift file
import Foundation
import SystemConfiguration
class Reachability {
var hostname: String?
var isRunning = false
var isReachableOnWWAN: Bool
var reachability: SCNetworkReachability?
var reachabilityFlags = SCNetworkReachabilityFlags()
let reachabilitySerialQueue = DispatchQueue(label: "ReachabilityQueue")
init(hostname: String) throws {
guard let reachability = SCNetworkReachabilityCreateWithName(nil, hostname) else {
throw Network.Error.failedToCreateWith(hostname)
}
self.reachability = reachability
self.hostname = hostname
isReachableOnWWAN = true
try start()
}
init() throws {
var zeroAddress = sockaddr_in()
zeroAddress.sin_len = UInt8(MemoryLayout<sockaddr_in>.size)
zeroAddress.sin_family = sa_family_t(AF_INET)
guard let reachability = withUnsafePointer(to: &zeroAddress, {
$0.withMemoryRebound(to: sockaddr.self, capacity: 1) {
SCNetworkReachabilityCreateWithAddress(nil, $0)
}
}) else {
throw Network.Error.failedToInitializeWith(zeroAddress)
}
self.reachability = reachability
isReachableOnWWAN = true
try start()
}
var status: Network.Status {
return !isConnectedToNetwork ? .unreachable :
isReachableViaWiFi ? .wifi :
isRunningOnDevice ? .wwan : .unreachable
}
var isRunningOnDevice: Bool = {
#if targetEnvironment(simulator)
return false
#else
return true
#endif
}()
deinit { stop() }
}
extension Reachability {
func start() throws {
guard let reachability = reachability, !isRunning else { return }
var context = SCNetworkReachabilityContext(version: 0, info: nil, retain: nil, release: nil, copyDescription: nil)
context.info = Unmanaged<Reachability>.passUnretained(self).toOpaque()
guard SCNetworkReachabilitySetCallback(reachability, callout, &context) else { stop()
throw Network.Error.failedToSetCallout
}
guard SCNetworkReachabilitySetDispatchQueue(reachability, reachabilitySerialQueue) else { stop()
throw Network.Error.failedToSetDispatchQueue
}
reachabilitySerialQueue.async { self.flagsChanged() }
isRunning = true
}
func stop() {
defer { isRunning = false }
guard let reachability = reachability else { return }
SCNetworkReachabilitySetCallback(reachability, nil, nil)
SCNetworkReachabilitySetDispatchQueue(reachability, nil)
self.reachability = nil
}
var isConnectedToNetwork: Bool {
return isReachable &&
!isConnectionRequiredAndTransientConnection &&
!(isRunningOnDevice && isWWAN && !isReachableOnWWAN)
}
var isReachableViaWiFi: Bool {
return isReachable && isRunningOnDevice && !isWWAN
}
/// Flags that indicate the reachability of a network node name or address, including whether a connection is required, and whether some user intervention might be required when establishing a connection.
var flags: SCNetworkReachabilityFlags? {
guard let reachability = reachability else { return nil }
var flags = SCNetworkReachabilityFlags()
return withUnsafeMutablePointer(to: &flags) {
SCNetworkReachabilityGetFlags(reachability, UnsafeMutablePointer($0))
} ? flags : nil
}
/// compares the current flags with the previous flags and if changed posts a flagsChanged notification
func flagsChanged() {
guard let flags = flags, flags != reachabilityFlags else { return }
reachabilityFlags = flags
NotificationCenter.default.post(name: .flagsChanged, object: self)
}
/// The specified node name or address can be reached via a transient connection, such as PPP.
var transientConnection: Bool { return flags?.contains(.transientConnection) == true }
/// The specified node name or address can be reached using the current network configuration.
var isReachable: Bool { return flags?.contains(.reachable) == true }
/// The specified node name or address can be reached using the current network configuration, but a connection must first be established. If this flag is set, the kSCNetworkReachabilityFlagsConnectionOnTraffic flag, kSCNetworkReachabilityFlagsConnectionOnDemand flag, or kSCNetworkReachabilityFlagsIsWWAN flag is also typically set to indicate the type of connection required. If the user must manually make the connection, the kSCNetworkReachabilityFlagsInterventionRequired flag is also set.
var connectionRequired: Bool { return flags?.contains(.connectionRequired) == true }
/// The specified node name or address can be reached using the current network configuration, but a connection must first be established. Any traffic directed to the specified name or address will initiate the connection.
var connectionOnTraffic: Bool { return flags?.contains(.connectionOnTraffic) == true }
/// The specified node name or address can be reached using the current network configuration, but a connection must first be established.
var interventionRequired: Bool { return flags?.contains(.interventionRequired) == true }
/// The specified node name or address can be reached using the current network configuration, but a connection must first be established. The connection will be established "On Demand" by the CFSocketStream programming interface (see CFStream Socket Additions for information on this). Other functions will not establish the connection.
var connectionOnDemand: Bool { return flags?.contains(.connectionOnDemand) == true }
/// The specified node name or address is one that is associated with a network interface on the current system.
var isLocalAddress: Bool { return flags?.contains(.isLocalAddress) == true }
/// Network traffic to the specified node name or address will not go through a gateway, but is routed directly to one of the interfaces in the system.
var isDirect: Bool { return flags?.contains(.isDirect) == true }
/// The specified node name or address can be reached via a cellular connection, such as EDGE or GPRS.
var isWWAN: Bool { return flags?.contains(.isWWAN) == true }
/// The specified node name or address can be reached using the current network configuration, but a connection must first be established. If this flag is set
/// The specified node name or address can be reached via a transient connection, such as PPP.
var isConnectionRequiredAndTransientConnection: Bool {
return (flags?.intersection([.connectionRequired, .transientConnection]) == [.connectionRequired, .transientConnection]) == true
}
}
func callout(reachability: SCNetworkReachability, flags: SCNetworkReachabilityFlags, info: UnsafeMutableRawPointer?) {
guard let info = info else { return }
DispatchQueue.main.async {
Unmanaged<Reachability>
.fromOpaque(info)
.takeUnretainedValue()
.flagsChanged()
}
}
extension Notification.Name {
static let flagsChanged = Notification.Name("FlagsChanged")
}
struct Network {
static var reachability: Reachability!
enum Status: String {
case unreachable, wifi, wwan
}
enum Error: Swift.Error {
case failedToSetCallout
case failedToSetDispatchQueue
case failedToCreateWith(String)
case failedToInitializeWith(sockaddr_in)
}
}
Usage
Initialize it in your AppDelegate.swift didFinishLaunchingWithOptions method and handle any errors that might occur:
import UIKit
#UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
var window: UIWindow?
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
do {
try Network.reachability = Reachability(hostname: "www.google.com")
}
catch {
switch error as? Network.Error {
case let .failedToCreateWith(hostname)?:
print("Network error:\nFailed to create reachability object With host named:", hostname)
case let .failedToInitializeWith(address)?:
print("Network error:\nFailed to initialize reachability object With address:", address)
case .failedToSetCallout?:
print("Network error:\nFailed to set callout")
case .failedToSetDispatchQueue?:
print("Network error:\nFailed to set DispatchQueue")
case .none:
print(error)
}
}
return true
}
}
And a view controller sample:
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default
.addObserver(self,
selector: #selector(statusManager),
name: .flagsChanged,
object: nil)
updateUserInterface()
}
func updateUserInterface() {
switch Network.reachability.status {
case .unreachable:
view.backgroundColor = .red
case .wwan:
view.backgroundColor = .yellow
case .wifi:
view.backgroundColor = .green
}
print("Reachability Summary")
print("Status:", Network.reachability.status)
print("HostName:", Network.reachability.hostname ?? "nil")
print("Reachable:", Network.reachability.isReachable)
print("Wifi:", Network.reachability.isReachableViaWiFi)
}
#objc func statusManager(_ notification: Notification) {
updateUserInterface()
}
}
Sample Project
For Swift 3, Swift 4 (working with cellular and Wi-Fi):
import SystemConfiguration
public class Reachability {
class func isConnectedToNetwork() -> Bool {
var zeroAddress = sockaddr_in(sin_len: 0, sin_family: 0, sin_port: 0, sin_addr: in_addr(s_addr: 0), sin_zero: (0, 0, 0, 0, 0, 0, 0, 0))
zeroAddress.sin_len = UInt8(MemoryLayout.size(ofValue: zeroAddress))
zeroAddress.sin_family = sa_family_t(AF_INET)
let defaultRouteReachability = withUnsafePointer(to: &zeroAddress) {
$0.withMemoryRebound(to: sockaddr.self, capacity: 1) {zeroSockAddress in
SCNetworkReachabilityCreateWithAddress(nil, zeroSockAddress)
}
}
var flags: SCNetworkReachabilityFlags = SCNetworkReachabilityFlags(rawValue: 0)
if SCNetworkReachabilityGetFlags(defaultRouteReachability!, &flags) == false {
return false
}
/* Only Working for WIFI
let isReachable = flags == .reachable
let needsConnection = flags == .connectionRequired
return isReachable && !needsConnection
*/
// Working for Cellular and WIFI
let isReachable = (flags.rawValue & UInt32(kSCNetworkFlagsReachable)) != 0
let needsConnection = (flags.rawValue & UInt32(kSCNetworkFlagsConnectionRequired)) != 0
let ret = (isReachable && !needsConnection)
return ret
}
}
Usage:
if Reachability.isConnectedToNetwork(){
print("Internet Connection Available!")
}else{
print("Internet Connection not Available!")
}
If someone is already using Alamofire then -
struct Connectivity {
static let sharedInstance = NetworkReachabilityManager()!
static var isConnectedToInternet:Bool {
return self.sharedInstance.isReachable
}
}
Usage:
if Connectivity.isConnectedToInternet {
print("Connected")
} else {
print("No Internet")
}
Create a new Swift file within your project, name it Reachability.swift. Cut & paste the following code into it to create your class.
import Foundation
import SystemConfiguration
public class Reachability {
class func isConnectedToNetwork() -> Bool {
var zeroAddress = sockaddr_in(sin_len: 0, sin_family: 0, sin_port: 0, sin_addr: in_addr(s_addr: 0), sin_zero: (0, 0, 0, 0, 0, 0, 0, 0))
zeroAddress.sin_len = UInt8(sizeofValue(zeroAddress))
zeroAddress.sin_family = sa_family_t(AF_INET)
let defaultRouteReachability = withUnsafePointer(&zeroAddress) {
SCNetworkReachabilityCreateWithAddress(kCFAllocatorDefault, UnsafePointer($0))
}
var flags: SCNetworkReachabilityFlags = SCNetworkReachabilityFlags(rawValue: 0)
if SCNetworkReachabilityGetFlags(defaultRouteReachability!, &flags) == false {
return false
}
let isReachable = flags == .Reachable
let needsConnection = flags == .ConnectionRequired
return isReachable && !needsConnection
}
}
You can check internet connection anywhere in your project using this code:
if Reachability.isConnectedToNetwork() {
println("Internet connection OK")
} else {
println("Internet connection FAILED")
}
If the user is not connected to the internet, you may want to show them an alert dialog to notify them.
if Reachability.isConnectedToNetwork() {
println("Internet connection OK")
} else {
println("Internet connection FAILED")
var alert = UIAlertView(title: "No Internet Connection", message: "Make sure your device is connected to the internet.", delegate: nil, cancelButtonTitle: "OK")
alert.show()
}
Explanation:
We are making a reusable public class and a method which can be used anywhere in the project to check internet connectivity. We require adding Foundation and System Configuration frameworks.
In the public class Reachability, the method isConnectedToNetwork() -> Bool { } will return a bool value about internet connectivity. We use a if loop to perform required actions on case. I hope this is enough. Cheers!
Apple has introduced Network Framework in iOS12.
import Foundation
import Network
class NetworkReachability {
var pathMonitor: NWPathMonitor!
var path: NWPath?
lazy var pathUpdateHandler: ((NWPath) -> Void) = { path in
self.path = path
if path.status == NWPath.Status.satisfied {
print("Connected")
} else if path.status == NWPath.Status.unsatisfied {
print("unsatisfied")
} else if path.status == NWPath.Status.requiresConnection {
print("requiresConnection")
}
}
let backgroudQueue = DispatchQueue.global(qos: .background)
init() {
pathMonitor = NWPathMonitor()
pathMonitor.pathUpdateHandler = self.pathUpdateHandler
pathMonitor.start(queue: backgroudQueue)
}
func isNetworkAvailable() -> Bool {
if let path = self.path {
if path.status == NWPath.Status.satisfied {
return true
}
}
return false
}
}
Use this for Swift-5+
import Foundation
import UIKit
import SystemConfiguration
public class InternetConnectionManager {
private init() {
}
public static func isConnectedToNetwork() -> Bool {
var zeroAddress = sockaddr_in()
zeroAddress.sin_len = UInt8(MemoryLayout.size(ofValue: zeroAddress))
zeroAddress.sin_family = sa_family_t(AF_INET)
guard let defaultRouteReachability = withUnsafePointer(to: &zeroAddress, {
$0.withMemoryRebound(to: sockaddr.self, capacity: 1) {
SCNetworkReachabilityCreateWithAddress(nil, $0)
}
}) else {
return false
}
var flags = SCNetworkReachabilityFlags()
if !SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags) {
return false
}
let isReachable = (flags.rawValue & UInt32(kSCNetworkFlagsReachable)) != 0
let needsConnection = (flags.rawValue & UInt32(kSCNetworkFlagsConnectionRequired)) != 0
return (isReachable && !needsConnection)
}
}
Usage:
if InternetConnectionManager.isConnectedToNetwork(){
print("Connected")
}else{
print("Not Connected")
}
Or Just use this framework for more Utilities: Link
Swift 5 solution:
Download ashleymills' Reachability class from
https://github.com/ashleymills/Reachability.swift.
Add the Reachability class to the project.
Put following code in the your class maintaining the connection status
class ConnectionManager {
static let shared = ConnectionManager()
private init () {}
func hasConnectivity() -> Bool {
do {
let reachability: Reachability = try Reachability()
let networkStatus = reachability.connection
switch networkStatus {
case .unavailable:
return false
case .wifi, .cellular:
return true
}
}
catch {
return false
}
}
}
Use it like below:
ConnectionManager.shared.hasConnectivity()
I have checked out implementing Ashley Mill's Reachability class without Cocoa Pods/Dependancy Manager. The idea is to make the Reachability dependency free in the project.
Xcode 7.2 - Swift 2.1
1) https://github.com/ashleymills/Reachability.swift. Download add the Reachability class to the project .
Note: While adding, please make sure 'copy items if needed' is ticked.
2) Make an AppManager.swift class . This class will cater as Public Model class where public methods & data will be added and can be utilised in any VC.
// AppManager.swift
import UIKit
import Foundation
class AppManager: NSObject{
var delegate:AppManagerDelegate? = nil
private var _useClosures:Bool = false
private var reachability: Reachability?
private var _isReachability:Bool = false
private var _reachabiltyNetworkType :String?
var isReachability:Bool {
get {return _isReachability}
}
var reachabiltyNetworkType:String {
get {return _reachabiltyNetworkType! }
}
// Create a shared instance of AppManager
final class var sharedInstance : AppManager {
struct Static {
static var instance : AppManager?
}
if !(Static.instance != nil) {
Static.instance = AppManager()
}
return Static.instance!
}
// Reachability Methods
func initRechabilityMonitor() {
print("initialize rechability...")
do {
let reachability = try Reachability.reachabilityForInternetConnection()
self.reachability = reachability
} catch ReachabilityError.FailedToCreateWithAddress(let address) {
print("Unable to create\nReachability with address:\n\(address)")
return
} catch {}
if (_useClosures) {
reachability?.whenReachable = { reachability in
self.notifyReachability(reachability)
}
reachability?.whenUnreachable = { reachability in
self.notifyReachability(reachability)
}
} else {
self.notifyReachability(reachability!)
}
do {
try reachability?.startNotifier()
} catch {
print("unable to start notifier")
return
}
}
private func notifyReachability(reachability:Reachability) {
if reachability.isReachable() {
self._isReachability = true
//Determine Network Type
if reachability.isReachableViaWiFi() {
self._reachabiltyNetworkType = CONNECTION_NETWORK_TYPE.WIFI_NETWORK.rawValue
} else {
self._reachabiltyNetworkType = CONNECTION_NETWORK_TYPE.WWAN_NETWORK.rawValue
}
} else {
self._isReachability = false
self._reachabiltyNetworkType = CONNECTION_NETWORK_TYPE.OTHER.rawValue
}
NSNotificationCenter.defaultCenter().addObserver(self, selector: "reachabilityChanged:", name: ReachabilityChangedNotification, object: reachability)
}
func reachabilityChanged(note: NSNotification) {
let reachability = note.object as! Reachability
dispatch_async(dispatch_get_main_queue()) {
if (self._useClosures) {
self.reachability?.whenReachable = { reachability in
self.notifyReachability(reachability)
}
self.reachability?.whenUnreachable = { reachability in
self.notifyReachability(reachability)
}
} else {
self.notifyReachability(reachability)
}
self.delegate?.reachabilityStatusChangeHandler(reachability)
}
}
deinit {
reachability?.stopNotifier()
if (!_useClosures) {
NSNotificationCenter.defaultCenter().removeObserver(self, name: ReachabilityChangedNotification, object: nil)
}
}
}
3) Make a Delegate Class. I use delegate method to notify the connectivity status.
// Protocols.swift
import Foundation
#objc protocol AppManagerDelegate:NSObjectProtocol {
func reachabilityStatusChangeHandler(reachability:Reachability)
}
4) Make Parent class of UIViewController (Inheritance method). The parent class have methods which are accessible all child VCs.
// UIappViewController.swift
import UIKit
class UIappViewController: UIViewController,AppManagerDelegate {
var manager:AppManager = AppManager.sharedInstance
override func viewDidLoad() {
super.viewDidLoad()
manager.delegate = self
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
func reachabilityStatusChangeHandler(reachability: Reachability) {
if reachability.isReachable() {
print("isReachable")
} else {
print("notReachable")
}
}
}
5) Start Real time Internet Connectivity Monitoring in AppDelegate.
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
AppManager.sharedInstance.initRechabilityMonitor()
return true
}
6) I have added a Swift File Name AppReference to store constant enum values.
// AppReference.swift
import Foundation
enum CONNECTION_NETWORK_TYPE : String {
case WIFI_NETWORK = "Wifi"
case WWAN_NETWORK = "Cellular"
case OTHER = "Other"
}
7) On ViewController (ex. You want to call an API only if network is available)
// ViewController.swift
import UIKit
class ViewController: UIappViewController {
var reachability:Reachability?
override func viewDidLoad() {
super.viewDidLoad()
manager.delegate = self
if(AppManager.sharedInstance.isReachability)
{
print("net available")
//call API from here.
} else {
dispatch_async(dispatch_get_main_queue()) {
print("net not available")
//Show Alert
}
}
//Determine Network Type
if(AppManager.sharedInstance.reachabiltyNetworkType == "Wifi")
{
print(".Wifi")
}
else if (AppManager.sharedInstance.reachabiltyNetworkType == "Cellular")
{
print(".Cellular")
}
else {
dispatch_async(dispatch_get_main_queue()) {
print("Network not reachable")
}
}
}
override func viewWillAppear(animated: Bool) {
}
override func didReceiveMemoryWarning() {
}
}
The sample can be downloaded # https://github.com/alvinreuben/Reachability-Sample
Upgraded to Swift 3.1-
https://github.com/alvinvgeorge/Reachability-UpgradedToSwift3
Although it does not directly answers your question, I would like to mention Apple recentely had this talk:
https://developer.apple.com/videos/play/wwdc2018/714/
At around 09:55 he talks about doing this stuff you are asking about:
Check connection
If connection -> Do something
If no connection -> Do something else (wait? retry?)
However, this has a few pitfalls:
What if in step 2 it says it has a connection, but 0.5 seconds later he hasn't?
What if the user is behind a proxy
Last but not least, what if some answers here can not determine the connectivity right? (I am sure that if you rapidly switch your connection, go to wi-fi and turn it off (just make it complicated), it almost never can correctly determine whetever I got a connection or not).
Quote from the video: "There is no way to guarentee whether a future operation will succeed or not"
The following points are some best practices according to Apple:
set waitsForConnectivity to true (https://developer.apple.com/documentation/foundation/urlsessionconfiguration/2908812-waitsforconnectivity)
respond to the delegate method taskIsWaitingForConnectivity (https://developer.apple.com/documentation/foundation/urlsessiontaskdelegate/2908819-urlsession). This is Apple's recommended way to check for connectivity, as mentioned in the video at 33:25.
According to the talk, there shouldn't be any reason to pre-check whetever you got internet connection or not, since it may not be accurate at the time you send your request to the server.
Many of these answers did not work anymore.
The reason was the use of vpn (because of corona, we now test over vpn instead of the companies wifi)
using apple's Network framework and based on code found here https://medium.com/#udaykiran.munaga/swift-check-for-internet-connectivity-14e355fa10c5 I was able to detect wifi and cellular each separate. The path in general stays satisfied due to the use of the vpn and therefore would always return true for isConnectedToNetwork().
Below the code that uses the apple Network framework, but rewritten so that it still uses Reachability.isConnectedToNetwork() in your existing code.
import Network
class Reachability {
static let shared = Reachability()
let monitorForWifi = NWPathMonitor(requiredInterfaceType: .wifi)
let monitorForCellular = NWPathMonitor(requiredInterfaceType: .cellular)
private var wifiStatus: NWPath.Status = .requiresConnection
private var cellularStatus: NWPath.Status = .requiresConnection
var isReachable: Bool { wifiStatus == .satisfied || isReachableOnCellular }
var isReachableOnCellular: Bool { cellularStatus == .satisfied }
func startMonitoring() {
monitorForWifi.pathUpdateHandler = { [weak self] path in
self?.wifiStatus = path.status
if path.status == .satisfied {
DLog.message("Wifi is connected!")
// post connected notification
} else {
DLog.message("No wifi connection.")
// post disconnected notification
}
}
monitorForCellular.pathUpdateHandler = { [weak self] path in
self?.cellularStatus = path.status
if path.status == .satisfied {
DLog.message("Cellular connection is connected!")
// post connected notification
} else {
DLog.message("No cellular connection.")
// post disconnected notification
}
}
let queue = DispatchQueue(label: "NetworkMonitor")
monitorForCellular.start(queue: queue)
monitorForWifi.start(queue: queue)
}
func stopMonitoring() {
monitorForWifi.cancel()
monitorForCellular.cancel()
}
class func isConnectedToNetwork() -> Bool {
return shared.isReachable
}
}
then in your Appdelegate didFinishLaunchingWithOptions: start monitoring.
Reachability.shared.startMonitoring()
As of iOS 12, NWPathMonitor replaced Reachability. Use this:
import Network
struct Internet {
private static let monitor = NWPathMonitor()
static var active = false
static var expensive = false
/// Monitors internet connectivity changes. Updates with every change in connectivity.
/// Updates variables for availability and if it's expensive (cellular).
static func start() {
guard monitor.pathUpdateHandler == nil else { return }
monitor.pathUpdateHandler = { update in
Internet.active = update.status == .satisfied ? true : false
Internet.expensive = update.isExpensive ? true : false
}
monitor.start(queue: DispatchQueue(label: "InternetMonitor"))
}
}
In use:
Internet.start()
if Internet.active {
// do something
}
if Internet.expensive {
// device is using Cellular data or WiFi hotspot
}
Swift 5
import SystemConfiguration
protocol Utilities {}
extension NSObject: Utilities {
enum ReachabilityStatus {
case notReachable
case reachableViaWWAN
case reachableViaWiFi
}
var currentReachabilityStatus: ReachabilityStatus {
var zeroAddress = sockaddr_in()
zeroAddress.sin_len = UInt8(MemoryLayout<sockaddr_in>.size)
zeroAddress.sin_family = sa_family_t(AF_INET)
guard let defaultRouteReachability = withUnsafePointer(to: &zeroAddress, {
$0.withMemoryRebound(to: sockaddr.self, capacity: 1) {
SCNetworkReachabilityCreateWithAddress(nil, $0)
}
}) else {
return .notReachable
}
var flags: SCNetworkReachabilityFlags = []
if !SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags) {
return .notReachable
}
if flags.contains(.reachable) == false {
// The target host is not reachable.
return .notReachable
}
else if flags.contains(.isWWAN) == true {
// WWAN connections are OK if the calling application is using the CFNetwork APIs.
return .reachableViaWWAN
}
else if flags.contains(.connectionRequired) == false {
// If the target host is reachable and no connection is required then we'll assume that you're on Wi-Fi...
return .reachableViaWiFi
}
else if (flags.contains(.connectionOnDemand) == true || flags.contains(.connectionOnTraffic) == true) && flags.contains(.interventionRequired) == false {
// The connection is on-demand (or on-traffic) if the calling application is using the CFSocketStream or higher APIs and no [user] intervention is needed
return .reachableViaWiFi
}
else {
return .notReachable
}
}
}
In any method use the below condition
if currentReachabilityStatus == .notReachable {
// Network Unavailable
} else {
// Network Available
}
Just figured this out for myself.
Xcode: 7.3.1, iOS 9.3.3
Using ashleymills/Reachability.swift as Reachability.swift in my project, I created the following function:
func hasConnectivity() -> Bool {
do {
let reachability: Reachability = try Reachability.reachabilityForInternetConnection()
let networkStatus: Int = reachability.currentReachabilityStatus.hashValue
return (networkStatus != 0)
}
catch {
// Handle error however you please
return false
}
}
Simply call hasConnectivity() where ever you need to check for a connection. This works for Wifi as well as Cellular.
Adding ashleymills's Reachability.swift so people dont have to move between sites:
Copyright (c) 2014, Ashley Mills
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice, this
list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
*/
// Reachability.swift version 2.2beta2
import SystemConfiguration
import Foundation
public enum ReachabilityError: ErrorType {
case FailedToCreateWithAddress(sockaddr_in)
case FailedToCreateWithHostname(String)
case UnableToSetCallback
case UnableToSetDispatchQueue
}
public let ReachabilityChangedNotification = "ReachabilityChangedNotification"
func callback(reachability:SCNetworkReachability, flags: SCNetworkReachabilityFlags, info: UnsafeMutablePointer<Void>) {
let reachability = Unmanaged<Reachability>.fromOpaque(COpaquePointer(info)).takeUnretainedValue()
dispatch_async(dispatch_get_main_queue()) {
reachability.reachabilityChanged(flags)
}
}
public class Reachability: NSObject {
public typealias NetworkReachable = (Reachability) -> ()
public typealias NetworkUnreachable = (Reachability) -> ()
public enum NetworkStatus: CustomStringConvertible {
case NotReachable, ReachableViaWiFi, ReachableViaWWAN
public var description: String {
switch self {
case .ReachableViaWWAN:
return "Cellular"
case .ReachableViaWiFi:
return "WiFi"
case .NotReachable:
return "No Connection"
}
}
}
// MARK: - *** Public properties ***
public var whenReachable: NetworkReachable?
public var whenUnreachable: NetworkUnreachable?
public var reachableOnWWAN: Bool
public var notificationCenter = NSNotificationCenter.defaultCenter()
public var currentReachabilityStatus: NetworkStatus {
if isReachable() {
if isReachableViaWiFi() {
return .ReachableViaWiFi
}
if isRunningOnDevice {
return .ReachableViaWWAN
}
}
return .NotReachable
}
public var currentReachabilityString: String {
return "\(currentReachabilityStatus)"
}
private var previousFlags: SCNetworkReachabilityFlags?
// MARK: - *** Initialisation methods ***
required public init(reachabilityRef: SCNetworkReachability) {
reachableOnWWAN = true
self.reachabilityRef = reachabilityRef
}
public convenience init(hostname: String) throws {
let nodename = (hostname as NSString).UTF8String
guard let ref = SCNetworkReachabilityCreateWithName(nil, nodename) else { throw ReachabilityError.FailedToCreateWithHostname(hostname) }
self.init(reachabilityRef: ref)
}
public class func reachabilityForInternetConnection() throws -> Reachability {
var zeroAddress = sockaddr_in()
zeroAddress.sin_len = UInt8(sizeofValue(zeroAddress))
zeroAddress.sin_family = sa_family_t(AF_INET)
guard let ref = withUnsafePointer(&zeroAddress, {
SCNetworkReachabilityCreateWithAddress(nil, UnsafePointer($0))
}) else { throw ReachabilityError.FailedToCreateWithAddress(zeroAddress) }
return Reachability(reachabilityRef: ref)
}
public class func reachabilityForLocalWiFi() throws -> Reachability {
var localWifiAddress: sockaddr_in = sockaddr_in(sin_len: __uint8_t(0), sin_family: sa_family_t(0), sin_port: in_port_t(0), sin_addr: in_addr(s_addr: 0), sin_zero: (0, 0, 0, 0, 0, 0, 0, 0))
localWifiAddress.sin_len = UInt8(sizeofValue(localWifiAddress))
localWifiAddress.sin_family = sa_family_t(AF_INET)
// IN_LINKLOCALNETNUM is defined in <netinet/in.h> as 169.254.0.0
let address: UInt32 = 0xA9FE0000
localWifiAddress.sin_addr.s_addr = in_addr_t(address.bigEndian)
guard let ref = withUnsafePointer(&localWifiAddress, {
SCNetworkReachabilityCreateWithAddress(nil, UnsafePointer($0))
}) else { throw ReachabilityError.FailedToCreateWithAddress(localWifiAddress) }
return Reachability(reachabilityRef: ref)
}
// MARK: - *** Notifier methods ***
public func startNotifier() throws {
guard !notifierRunning else { return }
var context = SCNetworkReachabilityContext(version: 0, info: nil, retain: nil, release: nil, copyDescription: nil)
context.info = UnsafeMutablePointer(Unmanaged.passUnretained(self).toOpaque())
if !SCNetworkReachabilitySetCallback(reachabilityRef!, callback, &context) {
stopNotifier()
throw ReachabilityError.UnableToSetCallback
}
if !SCNetworkReachabilitySetDispatchQueue(reachabilityRef!, reachabilitySerialQueue) {
stopNotifier()
throw ReachabilityError.UnableToSetDispatchQueue
}
// Perform an intial check
dispatch_async(reachabilitySerialQueue) { () -> Void in
let flags = self.reachabilityFlags
self.reachabilityChanged(flags)
}
notifierRunning = true
}
public func stopNotifier() {
defer { notifierRunning = false }
guard let reachabilityRef = reachabilityRef else { return }
SCNetworkReachabilitySetCallback(reachabilityRef, nil, nil)
SCNetworkReachabilitySetDispatchQueue(reachabilityRef, nil)
}
// MARK: - *** Connection test methods ***
public func isReachable() -> Bool {
let flags = reachabilityFlags
return isReachableWithFlags(flags)
}
public func isReachableViaWWAN() -> Bool {
let flags = reachabilityFlags
// Check we're not on the simulator, we're REACHABLE and check we're on WWAN
return isRunningOnDevice && isReachable(flags) && isOnWWAN(flags)
}
public func isReachableViaWiFi() -> Bool {
let flags = reachabilityFlags
// Check we're reachable
if !isReachable(flags) {
return false
}
// Must be on WiFi if reachable but not on an iOS device (i.e. simulator)
if !isRunningOnDevice {
return true
}
// Check we're NOT on WWAN
return !isOnWWAN(flags)
}
// MARK: - *** Private methods ***
private var isRunningOnDevice: Bool = {
#if (arch(i386) || arch(x86_64)) && os(iOS)
return false
#else
return true
#endif
}()
private var notifierRunning = false
private var reachabilityRef: SCNetworkReachability?
private let reachabilitySerialQueue = dispatch_queue_create("uk.co.ashleymills.reachability", DISPATCH_QUEUE_SERIAL)
private func reachabilityChanged(flags: SCNetworkReachabilityFlags) {
guard previousFlags != flags else { return }
if isReachableWithFlags(flags) {
if let block = whenReachable {
block(self)
}
} else {
if let block = whenUnreachable {
block(self)
}
}
notificationCenter.postNotificationName(ReachabilityChangedNotification, object:self)
previousFlags = flags
}
private func isReachableWithFlags(flags: SCNetworkReachabilityFlags) -> Bool {
if !isReachable(flags) {
return false
}
if isConnectionRequiredOrTransient(flags) {
return false
}
if isRunningOnDevice {
if isOnWWAN(flags) && !reachableOnWWAN {
// We don't want to connect when on 3G.
return false
}
}
return true
}
// WWAN may be available, but not active until a connection has been established.
// WiFi may require a connection for VPN on Demand.
private func isConnectionRequired() -> Bool {
return connectionRequired()
}
private func connectionRequired() -> Bool {
let flags = reachabilityFlags
return isConnectionRequired(flags)
}
// Dynamic, on demand connection?
private func isConnectionOnDemand() -> Bool {
let flags = reachabilityFlags
return isConnectionRequired(flags) && isConnectionOnTrafficOrDemand(flags)
}
// Is user intervention required?
private func isInterventionRequired() -> Bool {
let flags = reachabilityFlags
return isConnectionRequired(flags) && isInterventionRequired(flags)
}
private func isOnWWAN(flags: SCNetworkReachabilityFlags) -> Bool {
#if os(iOS)
return flags.contains(.IsWWAN)
#else
return false
#endif
}
private func isReachable(flags: SCNetworkReachabilityFlags) -> Bool {
return flags.contains(.Reachable)
}
private func isConnectionRequired(flags: SCNetworkReachabilityFlags) -> Bool {
return flags.contains(.ConnectionRequired)
}
private func isInterventionRequired(flags: SCNetworkReachabilityFlags) -> Bool {
return flags.contains(.InterventionRequired)
}
private func isConnectionOnTraffic(flags: SCNetworkReachabilityFlags) -> Bool {
return flags.contains(.ConnectionOnTraffic)
}
private func isConnectionOnDemand(flags: SCNetworkReachabilityFlags) -> Bool {
return flags.contains(.ConnectionOnDemand)
}
func isConnectionOnTrafficOrDemand(flags: SCNetworkReachabilityFlags) -> Bool {
return !flags.intersect([.ConnectionOnTraffic, .ConnectionOnDemand]).isEmpty
}
private func isTransientConnection(flags: SCNetworkReachabilityFlags) -> Bool {
return flags.contains(.TransientConnection)
}
private func isLocalAddress(flags: SCNetworkReachabilityFlags) -> Bool {
return flags.contains(.IsLocalAddress)
}
private func isDirect(flags: SCNetworkReachabilityFlags) -> Bool {
return flags.contains(.IsDirect)
}
private func isConnectionRequiredOrTransient(flags: SCNetworkReachabilityFlags) -> Bool {
let testcase:SCNetworkReachabilityFlags = [.ConnectionRequired, .TransientConnection]
return flags.intersect(testcase) == testcase
}
private var reachabilityFlags: SCNetworkReachabilityFlags {
guard let reachabilityRef = reachabilityRef else { return SCNetworkReachabilityFlags() }
var flags = SCNetworkReachabilityFlags()
let gotFlags = withUnsafeMutablePointer(&flags) {
SCNetworkReachabilityGetFlags(reachabilityRef, UnsafeMutablePointer($0))
}
if gotFlags {
return flags
} else {
return SCNetworkReachabilityFlags()
}
}
override public var description: String {
var W: String
if isRunningOnDevice {
W = isOnWWAN(reachabilityFlags) ? "W" : "-"
} else {
W = "X"
}
let R = isReachable(reachabilityFlags) ? "R" : "-"
let c = isConnectionRequired(reachabilityFlags) ? "c" : "-"
let t = isTransientConnection(reachabilityFlags) ? "t" : "-"
let i = isInterventionRequired(reachabilityFlags) ? "i" : "-"
let C = isConnectionOnTraffic(reachabilityFlags) ? "C" : "-"
let D = isConnectionOnDemand(reachabilityFlags) ? "D" : "-"
let l = isLocalAddress(reachabilityFlags) ? "l" : "-"
let d = isDirect(reachabilityFlags) ? "d" : "-"
return "\(W)\(R) \(c)\(t)\(i)\(C)\(D)\(l)\(d)"
}
deinit {
stopNotifier()
reachabilityRef = nil
whenReachable = nil
whenUnreachable = nil
}
}
Create a new Swift file within your project, name it Reachability.swift. Cut & paste the following code into it to create your class.
import Foundation
import SystemConfiguration
open class Reachability {
class func isConnectedToNetwork() -> Bool {
var zeroAddress = sockaddr_in()
zeroAddress.sin_len = UInt8(MemoryLayout.size(ofValue: zeroAddress))
zeroAddress.sin_family = sa_family_t(AF_INET)
let defaultRouteReachability = withUnsafePointer(to: &zeroAddress) {
$0.withMemoryRebound(to: sockaddr.self, capacity: 1) {zeroSockAddress in
SCNetworkReachabilityCreateWithAddress(nil, zeroSockAddress)
}
}
var flags = SCNetworkReachabilityFlags()
if !SCNetworkReachabilityGetFlags(defaultRouteReachability!, &flags) {
return false
}
let isReachable = (flags.rawValue & UInt32(kSCNetworkFlagsReachable)) != 0
let needsConnection = (flags.rawValue & UInt32(kSCNetworkFlagsConnectionRequired)) != 0
return (isReachable && !needsConnection)
}
}
you can call Reachability from anywhere of your code, just like
if Reachability.isConnectedToNetwork() {
print("Network is connected")
} else {
print("Network is not connected")
}
iOS12 Swift 4 and Swift 5
If you just want to check the connection, and your lowest target is iOS12, then you can use NWPathMonitor
import Network
It needs a little setup with some properties.
let internetMonitor = NWPathMonitor()
let internetQueue = DispatchQueue(label: "InternetMonitor")
private var hasConnectionPath = false
I created a function to get it going. You can do this on view did load or anywhere else. I put a guard in so you can call it all you want to get it going.
func startInternetTracking() {
// only fires once
guard internetMonitor.pathUpdateHandler == nil else {
return
}
internetMonitor.pathUpdateHandler = { update in
if update.status == .satisfied {
print("Internet connection on.")
self.hasConnectionPath = true
} else {
print("no internet connection.")
self.hasConnectionPath = false
}
}
internetMonitor.start(queue: internetQueue)
}
/// will tell you if the device has an Internet connection
/// - Returns: true if there is some kind of connection
func hasInternet() -> Bool {
return hasConnectionPath
}
Now you can just call the helper function hasInternet() to see if you have one. It updates in real time. See Apple documentation for NWPathMonitor. It has lots more functionality like cancel() if you need to stop tracking the connection, type of internet you are looking for, etc.
https://developer.apple.com/documentation/network/nwpathmonitor
While it may not directly determine whether the phone is connected to a network, the simplest(, cleanest?) solution would be to 'ping' Google, or some other server, (which isn't possible unless the phone is connected to a network):
private var urlSession:URLSession = {
var newConfiguration:URLSessionConfiguration = .default
newConfiguration.waitsForConnectivity = false
newConfiguration.allowsCellularAccess = true
return URLSession(configuration: newConfiguration)
}()
public func canReachGoogle() -> Bool
{
let url = URL(string: "https://8.8.8.8")
let semaphore = DispatchSemaphore(value: 0)
var success = false
let task = urlSession.dataTask(with: url!)
{ data, response, error in
if error != nil
{
success = false
}
else
{
success = true
}
semaphore.signal()
}
task.resume()
semaphore.wait()
return success
}
If you're concerned that the server may be down or may block your IP, you can always ping multiple servers in a similar fashion and return whether any of them are reachable. Or have someone set up a dedicated server just for this purpose.
if your project has a target above or equal iOS 12 and uses combine you could use this little piece of code.
import Combine
import Network
enum NerworkType {
case wifi
case cellular
case loopBack
case wired
case other
}
protocol ReachabilityServiceContract {
var reachabilityInfos: PassthroughSubject<NWPath, Never> { get set }
var isNetworkAvailable: CurrentValueSubject<Bool, Never> { get set }
var typeOfCurrentConnection: PassthroughSubject<NerworkType, Never> { get set }
}
final class ReachabilityService: ReachabilityServiceContract {
var reachabilityInfos: PassthroughSubject<NWPath, Never> = .init()
var isNetworkAvailable: CurrentValueSubject<Bool, Never> = .init(false)
var typeOfCurrentConnection: PassthroughSubject<NerworkType, Never> = .init()
private let monitor: NWPathMonitor
private let backgroudQueue = DispatchQueue.global(qos: .background)
init() {
monitor = NWPathMonitor()
setUp()
}
init(with interFaceType: NWInterface.InterfaceType) {
monitor = NWPathMonitor(requiredInterfaceType: interFaceType)
setUp()
}
deinit {
monitor.cancel()
}
}
private extension ReachabilityService {
func setUp() {
monitor.pathUpdateHandler = { [weak self] path in
self?.reachabilityInfos.send(path)
switch path.status {
case .satisfied:
self?.isNetworkAvailable.send(true)
case .unsatisfied, .requiresConnection:
self?.isNetworkAvailable.send(false)
#unknown default:
self?.isNetworkAvailable.send(false)
}
if path.usesInterfaceType(.wifi) {
self?.typeOfCurrentConnection.send(.wifi)
} else if path.usesInterfaceType(.cellular) {
self?.typeOfCurrentConnection.send(.cellular)
} else if path.usesInterfaceType(.loopback) {
self?.typeOfCurrentConnection.send(.loopBack)
} else if path.usesInterfaceType(.wiredEthernet) {
self?.typeOfCurrentConnection.send(.wired)
} else if path.usesInterfaceType(.other) {
self?.typeOfCurrentConnection.send(.other)
}
}
monitor.start(queue: backgroudQueue)
}
}
Just subscribe to the variable you want to follow and you should be updated of any changes.
Swift 5.5, iOS 12+, and no more third-party library.
Please check this gist https://gist.github.com/dimohamdy/5166ba6c88f6954fa6b23bc9f28cbe12
Usage
startNetworkReachabilityObserver()
if Reachability.shared.isConnected {
print("no internet connection")
}
Code
import Network
import Foundation
class Reachability {
static var shared = Reachability()
lazy private var monitor = NWPathMonitor()
var isConnected: Bool {
return monitor.currentPath.status == .satisfied
}
func startNetworkReachabilityObserver() {
monitor.pathUpdateHandler = { path in
if path.status == .satisfied {
NotificationCenter.default.post(name: Notifications.Reachability.connected.name, object: nil)
} else if path.status == .unsatisfied {
NotificationCenter.default.post(name: Notifications.Reachability.notConnected.name, object: nil)
}
}
let queue = DispatchQueue.global(qos: .background)
monitor.start(queue: queue)
}
}
I have made my own solution using NSTimer and Alamofire:
import Alamofire
public class ConnectionHelper: NSObject {
var request: Alamofire.Request?
func isInternetConnected(completionHandler: Bool -> Void) {
NSTimer.scheduledTimerWithTimeInterval(5.0, target: self, selector: "requestTimeout", userInfo: nil, repeats: false)
request = Alamofire
.request(
Method.HEAD,
"http://www.testurl.com"
)
.response { response in
if response.3?.code == -999 {
completionHandler(
false
)
} else {
completionHandler(
true
)
}
}
}
func requestTimeout() {
request!.cancel()
}
}
The NSTimer is used as a timeout, and was used due to unreliable results using the Alamofire timeout. The request should be made to a URL you trust to be reliable, such as your own server or the server that is hosting the services you depend on.
When the timer expires, the request is cancelled and the results are returned using a completion handler.
Usage:
ConnectionHelper().isInternetConnected() { internetConnected in
if internetConnected {
// Connected
} else {
// Not connected
}
}
If you are using Alamofire, you can do something like this:
let configuration = NSURLSessionConfiguration.defaultSessionConfiguration()
configuration.timeoutIntervalForRequest = 15 //Set timeouts in sec
configuration.timeoutIntervalForResource = 15
let alamoFireManager = Alamofire.Manager(configuration:configuration)
alamoFireManager?.request(.GET, "https://yourURL.com", parameters: headers, encoding: .URL)
.validate()
.responseJSON { response in
if let error = response.result.error {
switch error.code{
case -1001:
print("Slow connection")
return
case -1009:
print("No Connection!")
return
default: break
}
}
Xcode 14.0, Swift 5.7
To check for internet connection, use Apple's native Network framework. It has NWPathMonitor class-observer that you can implement to monitor and react to network changes.
import Network
class ViewController: UIViewController {
#IBOutlet var label: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
self.networkMonitoring()
}
fileprivate func networkMonitoring() {
let monitor = NWPathMonitor()
let queue = DispatchQueue(label: "monitoring")
monitor.start(queue: queue)
monitor.pathUpdateHandler = { path in
DispatchQueue.main.async {
switch path.status {
case .satisfied:
self.label.text = "Intenet connected"
self.view.backgroundColor = .systemGreen
case .unsatisfied:
self.label.text = "No Intenet"
self.view.backgroundColor = .systemRed
case .requiresConnection:
self.label.text = "May be activated"
self.view.backgroundColor = .systemBlue
#unknown default: fatalError()
}
}
}
}
}
here my solution for swift 2.3 with the lib (Reachability.swift)
Go into your Podfile and add :
pod 'ReachabilitySwift', '~> 2.4' // swift 2.3
Then into your terminal :
pod install
Then create a new file ReachabilityManager and add code below :
import Foundation
import ReachabilitySwift
enum ReachabilityManagerType {
case Wifi
case Cellular
case None
}
class ReachabilityManager {
static let sharedInstance = ReachabilityManager()
private var reachability: Reachability!
private var reachabilityManagerType: ReachabilityManagerType = .None
private init() {
do {
self.reachability = try Reachability.reachabilityForInternetConnection()
} catch {
print("Unable to create Reachability")
return
}
NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(ReachabilityManager.reachabilityChanged(_:)),name: ReachabilityChangedNotification,object: self.reachability)
do{
try self.reachability.startNotifier()
}catch{
print("could not start reachability notifier")
}
}
#objc private func reachabilityChanged(note: NSNotification) {
let reachability = note.object as! Reachability
if reachability.isReachable() {
if reachability.isReachableViaWiFi() {
self.reachabilityManagerType = .Wifi
} else {
self.reachabilityManagerType = .Cellular
}
} else {
self.reachabilityManagerType = .None
}
}
}
extension ReachabilityManager {
func isConnectedToNetwork() -> Bool {
return reachabilityManagerType != .None
}
}
How use it:
go into your AppDelegate.swift and add the code below :
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
ReachabilityManager.sharedInstance
}
Then when you want to check if the device is connected to internet do :
if ReachabilityManager.sharedInstance.isConnectedToNetwork() {
// Connected
} else {
// Not connected
}
For swift 3, I couldn't use just reachability from RAJAMOHAN-S solutions since it returns "true" if there is WiFi but no Internet. Thus, I implemented second validation via URLSession class and completion handler.
Here is the whole class.
import Foundation
import SystemConfiguration
public class Reachability {
class func isConnectedToNetwork() -> Bool {
var zeroAddress = sockaddr_in(sin_len: 0, sin_family: 0, sin_port: 0, sin_addr: in_addr(s_addr: 0), sin_zero: (0, 0, 0, 0, 0, 0, 0, 0))
zeroAddress.sin_len = UInt8(MemoryLayout.size(ofValue: zeroAddress))
zeroAddress.sin_family = sa_family_t(AF_INET)
let defaultRouteReachability = withUnsafePointer(to: &zeroAddress) {
$0.withMemoryRebound(to: sockaddr.self, capacity: 1) {zeroSockAddress in
SCNetworkReachabilityCreateWithAddress(nil, zeroSockAddress)
}
}
var flags: SCNetworkReachabilityFlags = SCNetworkReachabilityFlags(rawValue: 0)
if SCNetworkReachabilityGetFlags(defaultRouteReachability!, &flags) == false {
return false
}
// Working for Cellular and WIFI
let isReachable = (flags.rawValue & UInt32(kSCNetworkFlagsReachable)) != 0
let needsConnection = (flags.rawValue & UInt32(kSCNetworkFlagsConnectionRequired)) != 0
let ret = (isReachable && !needsConnection)
return ret
}
class func isInternetAvailable(webSiteToPing: String?, completionHandler: #escaping (Bool) -> Void) {
// 1. Check the WiFi Connection
guard isConnectedToNetwork() else {
completionHandler(false)
return
}
// 2. Check the Internet Connection
var webAddress = "https://www.google.com" // Default Web Site
if let _ = webSiteToPing {
webAddress = webSiteToPing!
}
guard let url = URL(string: webAddress) else {
completionHandler(false)
print("could not create url from: \(webAddress)")
return
}
let urlRequest = URLRequest(url: url)
let session = URLSession.shared
let task = session.dataTask(with: urlRequest, completionHandler: { (data, response, error) in
if error != nil || response == nil {
completionHandler(false)
} else {
completionHandler(true)
}
})
task.resume()
}
}
And you call this like this, for example:
Reachability.isInternetAvailable(webSiteToPing: nil) { (isInternetAvailable) in
guard isInternetAvailable else {
// Inform user for example
return
}
// Do some action if there is Internet
}
To check internet at an instance, this could be used, using Swift 5
import Foundation
import Alamofire
struct NetworkState {
var isInternetAvailable:Bool
{
return NetworkReachabilityManager()!.isReachable
}
}
And use it by:
if (NetworkState().isInternetAvailable) {
//connected to internet
}
I've made some improvement on Lex's example. I put some extra controls to solve double-trigger problem and also added notification support to listen status changes.
The controls that I've added to prevent the double-trigger problem, also show which connection source is using primarily by the device to internet access.
For example, even if the device is connected to both cellular and Wi-Fi at the same time, the "status" returns as "connectedViaWiFi" to indicating that the current internet access is over Wi-Fi.
import Foundation
import Network
class Reachability {
enum StatusFlag {
case unknow
case noConnection
case connectedViaWiFi
case connectedViaCellular
}
static let connectionStatusHasChangedNotification = NSNotification.Name("Reachability.connectionStatusHasChangedNotification")
static let shared = Reachability()
private var monitorForWifi: NWPathMonitor?
private var monitorForCellular: NWPathMonitor?
private var wifiStatus: NWPath.Status = .requiresConnection
private var cellularStatus: NWPath.Status = .requiresConnection
private var ignoreInitialWiFiStatusUpdate: Bool = true
private var ignoreInitialCelluluarStatusUpdate: Bool = true
private var isReachableOnCellular: Bool { cellularStatus == .satisfied }
private var isReachableOnWiFi: Bool { wifiStatus == .satisfied }
var status: StatusFlag = .unknow {
didSet {
guard status != oldValue else { return }
DispatchQueue.main.async { [weak self] in
NotificationCenter.default.post(name: Self.connectionStatusHasChangedNotification,
object: self?.status)
}
}
}
func startMonitoring() {
monitorForWifi = NWPathMonitor(requiredInterfaceType: .wifi)
monitorForWifi?.pathUpdateHandler = { [weak self] path in
self?.wifiStatus = path.status
self?.ignoreInitialWiFiStatusUpdate = false
self?.updateStatus()
}
monitorForCellular = NWPathMonitor(requiredInterfaceType: .cellular)
monitorForCellular?.pathUpdateHandler = { [weak self] path in
self?.cellularStatus = path.status
self?.ignoreInitialCelluluarStatusUpdate = false
self?.updateStatus()
}
let queue = DispatchQueue.global(qos: .background)
monitorForCellular?.start(queue: queue)
monitorForWifi?.start(queue: queue)
}
func stopMonitoring() {
monitorForWifi?.cancel()
monitorForWifi = nil
monitorForCellular?.cancel()
monitorForCellular = nil
wifiStatus = .requiresConnection
cellularStatus = .requiresConnection
status = .unknow
ignoreInitialWiFiStatusUpdate = true
ignoreInitialCelluluarStatusUpdate = true
}
private func updateStatus() {
if ignoreInitialWiFiStatusUpdate || ignoreInitialCelluluarStatusUpdate {
return
}
if !(isReachableOnCellular && isReachableOnWiFi) {
if isReachableOnCellular && !isReachableOnWiFi {
status = .connectedViaCellular
} else if isReachableOnWiFi && !isReachableOnCellular {
status = .connectedViaWiFi
} else {
status = .noConnection
}
} else {
status = .connectedViaWiFi
}
}
static func isConnectedToNetwork() -> Bool {
return shared.isReachableOnCellular || shared.isReachableOnWiFi
}
}
Sample usage
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(reachabilityChanged(_:)), name: Reachability.connectionStatusHasChangedNotification, object: nil)
Reachability.shared.startMonitoring()
}
#objc func reachabilityChanged(_ sender: Notification) {
guard let statusFlag = sender.object as? Reachability.StatusFlag else { return }
print("TEST -> statusFlag: \(statusFlag)")
}
With the help of below code you can check for internet Connection for both cellular network as well as for wifi.
language - Swift 3.0
import UIKit
import Foundation
import SystemConfiguration
class NetworkConnection: UIViewController {
class func isConnectedToNetwork() -> Bool {
var zeroAddress = sockaddr_in(sin_len: 0, sin_family: 0, sin_port: 0, sin_addr: in_addr(s_addr: 0), sin_zero: (0, 0, 0, 0, 0, 0, 0, 0))
zeroAddress.sin_len = UInt8(MemoryLayout.size(ofValue: zeroAddress))
zeroAddress.sin_family = sa_family_t(AF_INET)
guard let defaultRouteReachability = withUnsafePointer(to: &zeroAddress, {
$0.withMemoryRebound(to: sockaddr.self, capacity: 1) {
SCNetworkReachabilityCreateWithAddress(nil, $0)
}
}) else {
return false
}
var flags: SCNetworkReachabilityFlags = SCNetworkReachabilityFlags(rawValue: 0)
if SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags) == false {
return false
}
let isReachable = (flags.rawValue & UInt32(kSCNetworkFlagsReachable)) != 0
let needsConnection = (flags.rawValue & UInt32(kSCNetworkFlagsConnectionRequired)) != 0
return (isReachable && !needsConnection)
}
class func checkConnection(sender:UIViewController){
if NetworkConnection.isConnectedToNetwork() == true {
print("Connected to the internet")
// Do something
} else {
print("No internet connection")
let alertController = UIAlertController(title: "No Internet Available", message: "", preferredStyle: UIAlertControllerStyle.alert)
let okAction = UIAlertAction(title: "Ok", style: UIAlertActionStyle.default){(result:UIAlertAction) -> Void in
return
}
alertController.addAction(okAction)
sender.present(alertController, animated: true, completion: nil)
// Do something
}
}
}
Updated version of #martin's answer for Swift 5+ using Combine. This one also includes unavailibity reason check for iOS 14.
import Combine
import Network
enum NetworkType {
case wifi
case cellular
case loopBack
case wired
case other
}
final class ReachabilityService: ObservableObject {
#Published var reachabilityInfos: NWPath?
#Published var isNetworkAvailable: Bool?
#Published var typeOfCurrentConnection: NetworkType?
private let monitor = NWPathMonitor()
private let backgroundQueue = DispatchQueue.global(qos: .background)
init() {
setUp()
}
init(with interFaceType: NWInterface.InterfaceType) {
setUp()
}
deinit {
monitor.cancel()
}
}
private extension ReachabilityService {
func setUp() {
monitor.pathUpdateHandler = { [weak self] path in
self?.reachabilityInfos = path
switch path.status {
case .satisfied:
print("ReachabilityService: satisfied")
self?.isNetworkAvailable = true
break
case .unsatisfied:
print("ReachabilityService: unsatisfied")
if #available(iOS 14.2, *) {
switch path.unsatisfiedReason {
case .notAvailable:
print("ReachabilityService: unsatisfiedReason: notAvailable")
break
case .cellularDenied:
print("ReachabilityService: unsatisfiedReason: cellularDenied")
break
case .wifiDenied:
print("ReachabilityService: unsatisfiedReason: wifiDenied")
break
case .localNetworkDenied:
print("ReachabilityService: unsatisfiedReason: localNetworkDenied")
break
#unknown default:
print("ReachabilityService: unsatisfiedReason: default")
}
} else {
// Fallback on earlier versions
}
self?.isNetworkAvailable = false
break
case .requiresConnection:
print("ReachabilityService: requiresConnection")
self?.isNetworkAvailable = false
break
#unknown default:
print("ReachabilityService: default")
self?.isNetworkAvailable = false
}
if path.usesInterfaceType(.wifi) {
self?.typeOfCurrentConnection = .wifi
} else if path.usesInterfaceType(.cellular) {
self?.typeOfCurrentConnection = .cellular
} else if path.usesInterfaceType(.loopback) {
self?.typeOfCurrentConnection = .loopBack
} else if path.usesInterfaceType(.wiredEthernet) {
self?.typeOfCurrentConnection = .wired
} else if path.usesInterfaceType(.other) {
self?.typeOfCurrentConnection = .other
}
}
monitor.start(queue: backgroundQueue)
}
}
Usage:
In your view model:
private let reachability = ReachabilityService()
init() {
reachability.$isNetworkAvailable.sink { [weak self] isConnected in
self?.isConnected = isConnected ?? false
}.store(in: &cancelBag)
}
In your controller:
viewModel.$isConnected.sink { [weak self] isConnected in
print("isConnected: \(isConnected)")
DispatchQueue.main.async {
//Update your UI in here
}
}.store(in: &bindings)
There is no real way to do this, even APIs that do this will try to connect to a particular service and tell you if it succeed after previously failing, the best approach is to just try to connect to your service and handle the error appropriately, if you want some service that will notify you when you become connected, all that will happens is that it periodically calls to a fixed service until it gets a response and then let you know that it succeed, what if the problem is not the internet itself but the specific service you are trying to connect to.
The best approach to this is to design in you connection methods of handling this itself, you can trigger a retry in some given amount of time depending on your error, maybe the number of failures, you can return an error which you can use to display an error message giving the user a possibility to try again, maybe a combination of the try a few time, then return and error.
Another problem similar to this is sending messages you already have sent but haven't gotten a response to, again its best to just write your app to handle this, ignoring request until the one its waiting for has returned, cancelling waiting request if the request is different, etc
Theses things can be written in pretty generic ways so they can be used in many different aspects of your app or even different projects.
This is my version. Essentially it doesn't bring anything new. I bound it to UIDevice.
import UIKit
import SystemConfiguration
extension UIDevice {
open class var isConnectedToNetwork: Bool {
get {
var zeroAddress = sockaddr_in()
zeroAddress.sin_len = UInt8(MemoryLayout.size(ofValue: zeroAddress))
zeroAddress.sin_family = sa_family_t(AF_INET)
guard
let defaultRouteReachability: SCNetworkReachability = withUnsafePointer(to: &zeroAddress, {
$0.withMemoryRebound(to: sockaddr.self, capacity: 1) {
SCNetworkReachabilityCreateWithAddress(nil, $0)
}
}),
var flags: SCNetworkReachabilityFlags = SCNetworkReachabilityFlags() as SCNetworkReachabilityFlags?,
SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags)
else { return false }
return flags.contains(.reachable) && !flags.contains(.connectionRequired)
}
}
}
print("Network status availability: " + ( UIDevice.isConnectedToNetwork ? "true" : "false" ))
here is the same code with accepted answer but I find it more useful for some cases to use closures
import SystemConfiguration
public class Reachability {
class func isConnectedToNetwork(isConnected : (Bool) -> ()) {
var zeroAddress = sockaddr_in(sin_len: 0, sin_family: 0, sin_port: 0, sin_addr: in_addr(s_addr: 0), sin_zero: (0, 0, 0, 0, 0, 0, 0, 0))
zeroAddress.sin_len = UInt8(MemoryLayout.size(ofValue: zeroAddress))
zeroAddress.sin_family = sa_family_t(AF_INET)
let defaultRouteReachability = withUnsafePointer(to: &zeroAddress) {
$0.withMemoryRebound(to: sockaddr.self, capacity: 1) {zeroSockAddress in
SCNetworkReachabilityCreateWithAddress(nil, zeroSockAddress)
}
}
var flags: SCNetworkReachabilityFlags = SCNetworkReachabilityFlags(rawValue: 0)
if SCNetworkReachabilityGetFlags(defaultRouteReachability!, &flags) == false {
isConnected(false)
}
/* Only Working for WIFI
let isReachable = flags == .reachable
let needsConnection = flags == .connectionRequired
return isReachable && !needsConnection
*/
// Working for Cellular and WIFI
let isReachable = (flags.rawValue & UInt32(kSCNetworkFlagsReachable)) != 0
let needsConnection = (flags.rawValue & UInt32(kSCNetworkFlagsConnectionRequired)) != 0
let ret = (isReachable && !needsConnection)
isConnected(ret)
}
}
and here is how to use it:
Reachability.isConnectedToNetwork { (isConnected) in
if isConnected {
//We have internet connection | get data from server
} else {
//We don't have internet connection | load from database
}
}