Alamofire Appending Data - ios

Question

I have a simple Alamofire request and i'm parsing it with SwiftyJSON. Here is code:
var fetchedData: [TestDB]? = []
func fetchData() {
Alamofire.request(url!, method: .get).validate().responseJSON { response in
switch response.result {
case .success(let value):
let json = JSON(value)
self.fetchedData = [TestDB]()
for dict in json["articles"].array! {
let data = TestDB()
if let image = dict["urlToImage"].string {
data.imageUrls = image
}
if let titlee = dict["title"].string {
data.titlee = titlee
}
if let desc = dict["description"].string {
data.desc = desc
}
self.fetchedData?.append(data)
// If i print fetchedData here, i can see it has right values.
// print(fetchedData)
}
case .failure(let error):
print(error)
}
}
// If i try to print fetchedData here, it's empty.
}
As i said in code, i can't append and use my datas. I think that's something with Alamofire being asynchronous. But couldn't figure out why. Any help is appreciated. Thanks!

Answer 1

When you use asynchronous method you have some way to proceed, for example:
use callback
use RAC/observation
Callback:
func fetchData(completion: (result: [TestDB]) -> ) {
Alamofire.request(url!, method: .get).validate().responseJSON { response in
self.fetchedData = [TestDB]()
// fill self.fetchedData then:
completion(self.fetchedData)
}
})
Where you call fetchData:
self.fetchData(completion: {
// update collectionview?
self.collectionView.reloadData()
})
RAC:
You can find all documentation here.
Plus:
Some suggestion:
self.fetchedData = TestDB is not necessary, probably is sufficient self.fetchData.removeAll()
use ObjectMappar to map any json response to object