Check Internet connection availability?

Question

I just need to check the internet connection availability before start communicating with the service in my iphone App. I am using Swift 1.2 and Xcode 6 as my development environment...

I've just done some research and found this stackoverflow LINK in objective C.

Therefore I just tried to find a similar solution in SWIFT and found the following link

https://coderwall.com/p/mhxbpq/checking-for-internet-connection-availability

Just to make things easy the content in that link is as follows...

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
  }

}

And check the connection availability like this...

if Reachability.isConnectedToNetwork() 
{
    println("Haz Interwebz!")
}  
else
{
    println("Oh noes! No interwebz!!!")
}

NOTE: To work this needs to add SystemConfiguration.framework to the project (For "Linked Frameworks and Libraries")....

So.... My question is, I am quite new for iOS development and NOT quite sure how good and relaible it is to use this logic to get it done. Most of the stuff in that class are completely not clear, but the small tests I've done works good!!!

Like to hear what more experiance ios developers have to say about this.

Answer 1

I was looking to solve the same problem for myself this morning and I felt that this "Reachability" sample code provided from Apple does not appeal to me at all (mostly because of the manual opening of sockets and the SystemConfiguration ugly API).

Instead of this I tried to make a simple HTTP connection to a random non-existing URL using Alamofire (I already had it as a dependency) and check the value in the error that I would receive.

Alamofire.request(.GET, "http://superrandomdomainnamethatisnotused.com/superrandompath").responseString {
    (request, response, stringData, error) in

    if let networkError = error {
        if (networkError.code == -1009) {
            println("No Internet \(error)")
        }
    }
}

This code could be rewritten using any other networking library. Error -1009 is corresponding to NSURLErrorNotConnectedToInternet which is somewhat more reassuring way of saying "you are really not connected to the Internet".

Another good thing is that this works even if you put non-existing URL, which means that you don't have to make a successful HTTP request to any server even if you have Internet connection.

The downside is that the code in the block is executed asynchronously, which could be inconvenience depending on your requirements.