Check for internet connection availability in Swift

Question

Is there a way to check if the internet connection is available using Swift?

I know there are many third party libraries to do this but they are all written in Objective-C. I'm looking for a Swift alternative.

Answer 1

As mentioned in the comments, although its possible to use Objective-C libraries in Swift, I wanted a more pure Swift solution. The existing Apple Reachability class and other third party libraries seemed to be too complicated for me to translate to Swift. I Googled some more and I came across this article which shows a simple method to check for network availability. I set out to translate this to Swift. I hit many snags but thanks to Martin R from StackOverflow, I managed to resolve them and finally get a workable solution in Swift. Here is the code.

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(nil, UnsafePointer($0)).takeRetainedValue()         }          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     }  } 

For Swift > 3.0

public class Reachability {     public func isConnectedToNetwork() -> Bool {         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 false         }          var flags: SCNetworkReachabilityFlags = []         if !SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags) {             return false         }         if flags.isEmpty {             return false         }          let isReachable = flags.contains(.reachable)         let needsConnection = flags.contains(.connectionRequired)          return (isReachable && !needsConnection)     } } 

This works for both 3G and WiFi connections. I've also uploaded it to my GitHub with a working example.