Handle Alamofire asynchronous request using SwiftyJSON - json

Question

I am trying to parse JSON data using SwiftyJSON into an array to use in my TableView. However even though I can successfully request the data and parse it into an array, I cannot return it from the getObjects function as it is done asynchronously. I have tried to use a completion handler, and after following several tutorials it seems I am missing something.
Does anybody know how I can return the array to use in my TableViewController ?
Table View Controller
let objects = [Objects]()
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
let urlString = "URLSTRING"
objects = dataManager.getObjects(urlString)
print("objects in view controller products array \(objects.count)")
self.tableView.reloadData
}
Request Functions
class DataManager {
func requestObjects(_ stringUrl: String, success:#escaping (JSON) -> Void, failure:#escaping (Error) -> Void) {
print("Request Data")
Alamofire.request(stringUrl, method: .get).validate().responseJSON { response in
switch response.result {
case .success(let value):
let json = JSON(value)
print("responce success")
success(json)
case .failure(let error):
print(error)
} //End of switch statement
} //End of alamofire request
} //End of request function
func getObjects(_ urlString:String) -> [Object] {
var objects = [Object]()
requestObjects(urlString, success: { (JSONResponse) -> Void in
let json = JSONResponse
for item in json["items"] {
let title = item.1["title"].string
objects.append(Object(title: title!))
}
print("Number of objects = \(objects.count)")
}) {
(error) -> Void in
print(error)
}
print(objects) // Prints empty array
return objects // Array is empty
}
}

Answer 1

You need to use completionHandler to return data to TableViewController.
func getObjects(completionHandler : #escaping ([Object]) -> (),_ urlString:String) -> [Sneaker] {
var objects = [Object]()
requestObjects(urlString, success: { (JSONResponse) -> Void in
let json = JSONResponse
for item in json["items"] {
let title = item.1["title"].string
objects.append(Object(title: title!))
}
completionHandler(objects)
print("Number of objects = \(objects.count)")
}) {
(error) -> Void in
print(error)
}
print(objects) // Prints empty array
return objects // Array is empty
}
}
In your TableViewController
dataManager.getObject(completionHandler: { list in
self.objects = list
}, urlString)
There could be some syntax error i didnt test it