The entire process to create current application is as follows:

1. Create a simple single view application for iOS
2. Design the UI
3. Close the application
4. Install cocoapods.org unless you did in the past
5. cd to your application workspace
6. run pod setup --verbose
7. run pod init
8. open your Podfile with your editor
9. Pods 8.1 uncomment the specification 8.2 add required pods 8.2.1 pod 'SwiftyJSON' 8.2.2 pod 'SVProgressHUD' 8.2.3 pod 'Alamofire' 8.3 save 8.4 run pod install
10. open *.xcoprojectworks
11. let WeatherViewController to inherit from CLLocationManagerDelegate
12. define locationManger = CLLocationManager
13. in viewDidLoad() 12.1. set locationManager to self 12.2. set locationManager.desiredAccuracy to your preference or requirement 12.3. set locationManager.requestWhenInUseAuthorization()
14. open Info.plist 13.1. add Privacy - Location When In Use Description 13.2. add Privacy - Location Usage Discription 13.3. we use Open Weather Map via http add the following

  <key>NSAppTransportSecurity</key>
  <dict>
    <key>NSExceptionDomains</key>
    <dict>
      <key>openweathermap.org</key>
      <dict>
         <key>NSIncludesSubdomains</key>
         <true/>
         <key>NSTemporaryExceptionAllowsInsecureHTTPLoads</key>
         <true/>
      </dict>
    </dict>
  </dict>

14. write function didUpdateLocations

• check last location in locations variable
• if it owns higher value than 0 then get 'longitude' and 'latitude' variable
• stopUpdatingLocation() and set locationManager.delegate to nil

15. write function didFailWithError

• print error
• inform user by updating cityLabel with 'Location's unavailable'

16. call startUpdatingLocation function in viewDidLoad function
17. create a params dictionary variable and save latitude, longitude and appid in it.
18. cal getWeatherData and provide url and parameters for it
19. import Alamofire and SwiftyJSON
20. complete Alamofire.request(url, method: .get, parameters: parameters).responseJSON {}
21. then check the if response.result is success or failure
22. save the response.result.value in an unwraped variable as a JSON type
23. create a class named WeatherDataModel and declare variables as the following list

24. also add a function named updateWeatherIcon which implements a switch statement to convert code to an icon.
25. call the updateUIWithWeatherData function and set the available data.
26. Navigating Data Between View Controllers. In ChangeCityViewController declare a protocol and define userEnteredANewCityName function that requires a string value. NOTE definition must be before the class definition.
27. declare an optional delegate variable of the created protocol. NOTE by convention the name of this variable is delegate.
28. in getWeatherPressed function, assign the text of text field to a variable and if it's not nil call the userEneteredANewCityName function by passing city name on delegate variable.
29. dismiss the current view controller by calling self.dismiss(animated: true, completion: nil) function.
30. in WeatherViewController, confirm to inherite ChangeCityDelegate.
31. implement goToChangeCityViewControllerButtonPressed by calling performSegue(withIdentifie: "identifier's name", sender: self).
32. implement change city view delegate method, define a dictionary variable and store "q" as a city name and app_id. Then call getWeatherData.
33. override prepare function for segue and check if the segue.identifier is equal to segue's name then create segue.destination a viewcontroller variable as! ChangeCityViewController and then assign its delegate to self