Check if internet connection availabile in swift

Question

Is there an Apple framework bundle to detect if there's an internet connection? Currently my application crashes when it tries to geolocate the user's position without an internet connection.

/*inside locationManager didUpdateLocations method*/
var currentLocation:CLLocation? = locations[0] as? CLLocation
geocoder = CLGeocoder()
//Crashes on line below when there isn't an internet connection
//Need to add function to check if internet connection is live 
//Before running reverseGeocodeLocation
geocoder.reverseGeocodeLocation (currentLocation,handleGeocode)

I'm a bit new to swift and ios programming - my apologies.

Answer 1

Not a full-fledged network checking library but I found this simple method for checking the network availability. I managed to translate it to Swift and here the final 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) ? true : false
    }

}

It works for both 3G and WiFi connections. I've also uploaded it to my Github with a working example. If you're looking for a simple way to check for network availability purely in Swift, you can use it.

Answer 2

Using Babatunde's code sample but here is an updated version for Swift 2.0 and error handling: EDIT: Also changed the URL for Google as HTTPS for iOS 9. EDIT2: Original article: http://www.brianjcoleman.com/tutorial-check-for-internet-connection-in-swift/

import Foundation
import SystemConfiguration

public class Reachability {

    // Check if internet connection is available

    class func isConnectedToNetwork() -> Bool {

        var status:Bool = false

        let url = NSURL(string: "https://google.com")
        let request = NSMutableURLRequest(URL: url!)
        request.HTTPMethod = "HEAD"
        request.cachePolicy = NSURLRequestCachePolicy.ReloadIgnoringLocalAndRemoteCacheData
        request.timeoutInterval = 10.0

        var response:NSURLResponse?

        do {
            let _ = try NSURLConnection.sendSynchronousRequest(request, returningResponse: &response) as NSData?
        }
        catch let error as NSError {
            print(error.localizedDescription)
        }

        if let httpResponse = response as? NSHTTPURLResponse {
            if httpResponse.statusCode == 200 {
                status = true
            }
        }
        return status
   }
}

Answer 3

As Reachability has not been fully ported to swift yet, you can use the sample code below to check for internet connection:

public class Reachability {
/**
 * Check if internet connection is available
 */
class func isConnectedToNetwork() -> Bool {
    var status:Bool = false

    let url = NSURL(string: "http://google.com")
    let request = NSMutableURLRequest(URL: url!)
    request.HTTPMethod = "HEAD"
    request.cachePolicy = NSURLRequestCachePolicy.ReloadIgnoringLocalAndRemoteCacheData
    request.timeoutInterval = 10.0

    var response:NSURLResponse?

    var data = NSURLConnection.sendSynchronousRequest(request, returningResponse: &response, error: nil) as NSData?

    if let httpResponse = response as? NSHTTPURLResponse {
        if httpResponse.statusCode == 200 {
            status = true
        }
    }

    return status
  }
}

See sample usage of the function below:

// Check if internet is available before proceeding further
    if Reachability.isConnectedToNetwork() {
        // Go ahead and fetch your data from the internet
        // ...
    } else {
        println("Internet connection not available")

        var alert = UIAlertView(title: "No Internet connection", message: "Please ensure you are connected to the Internet", delegate: nil, cancelButtonTitle: "OK")
        alert.show()
    }