Check internet connection

Reachability.swift

//
//  Reachability.swift
//
//  Created by Vasiliy Savchuk on 06.02.17.
//  Copyright © 2017 All rights reserved.
//
// Usage this snippet:
//   guard Reachability.sharedInstance.isReachable else {
//       show alert
//       return
//   }

import Foundation
import Alamofire

class Reachability {
    
    let networkReachabilityManager = NetworkReachabilityManager()

    var isReachableWiFi: Bool = false
    
    var isReachable: Bool = false {
        didSet {
            NotificationCenter.sendNotification(name:Notification.Name.Reachability.didChange)
        }
    }
    
    //MARK: - Class Methods
    
    static let sharedInstance : Reachability = {
        
        let instance = Reachability()
        instance.observeReachability()
        instance.networkReachabilityManager?.startListening()
        
        return instance
        
    }()
    
    //MARK: - Methods
    
    func observeReachability() {
        
        networkReachabilityManager?.listener = { status in
            print("Network Status Changed: \(status)")
            switch status {
                
            case .notReachable:
            
                self.isReachable = false
                self.isReachableWiFi = false
                
                break
            case .reachable(NetworkReachabilityManager.ConnectionType.ethernetOrWiFi):

                self.isReachable = true
                self.isReachableWiFi = true
                
                break
                
            case .reachable(NetworkReachabilityManager.ConnectionType.wwan), .unknown:
                
                self.isReachable = true
                self.isReachableWiFi = false
                
                break
            }
        }
    }
    
}