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iOS Build a Weather App with Swift Managing Complexity ForecastService

Posted by Kevin Gonzales
Kevin Gonzales
4,638 Points

Can someone go over Completion?

I do not fully understand what happens when we do this completion(currentWeather). Could someone elaborate?

also this statement let currentWeather = self.currentWeatherFromJSON(JSONDictionary)

what is the self referring to in here?

Erwin Gaitan Ospino
Erwin Gaitan Ospino
3,102 Points

what completion(currentWeather) does is executing the function that we pass to getForecast when we call it. For example:

let network = NetworkOperation(...)
network.getForecast() {
  (let response) in 
  println(reponse)
  // The response here will 
  // be currentWheater (which is passed in 
  // on the definition of the method getForecast)
}

So, basically when we call the network.getForecast method, the function that we pass to it, won't be executed until completion(currentWeather) is executed. This is known as a callback.

Kevin Gonzales
Kevin Gonzales
4,638 Points

Thanks! I think I get it better!

Kevin Gonzales
Kevin Gonzales
4,638 Points

I can't give a best answer for some reason tough

1 Answer

Frank Novello
Frank Novello
19,299 Points
Frank Novello
Frank Novello
19,299 Points

seriously...very frustrating..

Brian Patterson
Brian Patterson
19,588 Points

I to am finding this very frustrating.