DispatchGroup with Asynchronous function - ios

Question

I use Alamofire for get a request. I have two UIViewControllers and I use prepare (segue) function for send the data between the both.
On my first view controller, I use Alamofire but when I use prepare (segue), all my informations are empty.
#IBAction func loginPage(_ sender: UIButton) {
let group = DispatchGroup()
Helper().alomofirePost(URL: "http://192.168.1.7/app_dev.php/login_check", Paramaters: paramaters) { contenuJSON in
if (contenuJSON["connected"].stringValue == "true") {
group.enter()
self.dashboad()
group.leave()
group.notify(queue: DispatchQueue.main) {
//print(self.image) // EMPTY
print(self.info[0]) // EMPTY FATAL ERROR INDEXT OUT OF RANGE
self.performSegue(withIdentifier: "Dashboard", sender: self)
}
}
}
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "Dashboard" {
let success = segue.destination as! DashboardViewController
success.profil = self.image
}
}
func dashboad() {
// Other Function
//self.image = addPicProfil()
self.info = add_info(url: "http://192.168.1.7/app_dev.php/dashboard/info")
}
func add_info(url: String) -> [String] {
var info = [String]()
Helper().alomofireGet(URL: url) { contentJSON in
var content = contentJSON
print(content)
info.append(contentJSON["userFirstName"].stringValue)
info.append(contentJSON["countDevices"].stringValue)
info.append(contentJSON["earnedThisYearsEUR"].stringValue)
info.append(contentJSON["countCampaigns"].stringValue)
}
return (info)
}
In my Helper File I have :
func alomofireGet(URL: String, onCompletion:#escaping ((JSON) -> Void)) {
var contentJSON = JSON()
Alamofire.request(URL, method: .get).responseJSON() { (reponse) in
if reponse.result.isSuccess {
contentJSON = JSON(reponse.result.value!)
} else {
contentJSON = JSON(reponse.result.error!)
}
onCompletion(contentJSON)
}
}
func alomofirePost(URL: String, Paramaters: Dictionary<String, Any>, onCompletion: #escaping ((_ response: JSON) -> Void)) {
Alamofire.request(URL, method: .post, parameters: Paramaters).validate().responseJSON { (reponse) in
var contenuJSON = JSON()
if reponse.result.isSuccess {
contenuJSON = JSON(reponse.result.value!)
} else {
contenuJSON = JSON(reponse.result.error!)
}
onCompletion(contenuJSON)
}
}

Answer 1

You mess use DispatchQueue info is nil as you think that this
self.info = add_info(url: "http://192.168.1.7/app_dev.php/dashboard/info")
will add the asynchronous values appended but it will return an empty array , you need
func add_info(url: String,completion:#escaping(_ arr:[String]) -> ()) {
var info = [String]()
Helper().alomofireGet(URL: url) { contentJSON in
print(contentJSON)
info.append(contentJSON["userFirstName"].stringValue)
info.append(contentJSON["countDevices"].stringValue)
info.append(contentJSON["earnedThisYearsEUR"].stringValue)
info.append(contentJSON["countCampaigns"].stringValue)
completion(info)
}
}