Swift: passing values from different scopes in closures - ios

Question

Evening, I'm fetching the data from an API, and I'm having problems to passing the masons through different scopes:
I have this fun in my controller:
func getDaily() {
let json = NetworkManager.getDaily()
print(json)
}
And this one in a NetworkManager Class
class func getDaily() -> JSON {
//Setting the url for the request
let url = "\(base_url)planetary/apod?api_key=\(apy_key)"
var json: JSON = []
//Making the request
Alamofire.request(url, method: .get).validate().responseJSON{ response in
switch response.result {
case .success(let value):
json = JSON(value)
//print("JSON: \(json)")
case .failure(let error):
print(error)
}
}
return json
}
and obviously the json printing in the first func is always empty.
Can you please explain me the way to do this?

Answer 1

Your function getDaily() should not be returning JSON. Because this is an async request you need a callback. Try it like this:
class func getDaily(result: #escaping (JSON) -> ()) {
//Setting the url for the request
let url = "\(base_url)planetary/apod?api_key=\(apy_key)"
var json: JSON = []
//Making the request
Alamofire.request(url, method: .get).validate().responseJSON{ response in
switch response.result {
case .success(let value):
json = JSON(value)
result(json)
case .failure(let error):
print(error)
}
}
}
Your caller would then become:
func getDaily() {
NetworkManager.getDaily { json in
print(json)
}
}

Answer 2

For me this is the correct way:
import UIKit
import Alamofire
class APIManager: NSObject {
static let sharedInstance = APIManager()
//TODO :-
/* Handle Time out request alamofire */
func requestGETURL(_ strURL: String, success:#escaping (JSON) -> Void, failure:#escaping (Error) -> Void)
{
Alamofire.request(strURL).responseJSON { (responseObject) -> Void in
//print(responseObject)
if responseObject.result.isSuccess {
let resJson = JSON(responseObject.result.value!)
//let title = resJson["title"].string
//print(title!)
success(resJson)
}
if responseObject.result.isFailure {
let error : Error = responseObject.result.error!
failure(error)
}
}
}
func requestPOSTURL(_ strURL : String, params : [String : AnyObject]?, headers : [String : String]?, success:#escaping (JSON) -> Void, failure:#escaping (Error) -> Void){
Alamofire.request(strURL, method: .post, parameters: params, encoding: JSONEncoding.default, headers: headers).responseJSON { (responseObject) -> Void in
if responseObject.result.isSuccess {
let resJson = JSON(responseObject.result.value!)
success(resJson)
}
if responseObject.result.isFailure {
let error : Error = responseObject.result.error!
failure(error)
}
}
}
}
/********************************* To get response in another class ********************************/
APIManager.sharedInstance.requestPOSTURL(HttpsUrl.Address, params: dict as [String : AnyObject]?, headers: nil, success: { (json) in
// success code
print(json)
}, failure: { (error) in
//error code
print(error)
})