Thread 1 : signal SIGABRT alamofire - swift

Question

I'm very new to Swift 3, and i have to do a GET request on my API. I'm using Alamofire, which uses Asynchronous functions.
I do exactly the same on my Android App, and the GET returns JSON data
This is my code in swift :
func getValueJSON() -> JSON {
var res = JSON({})
let myGroup = DispatchGroup()
myGroup.enter()
Alamofire.request(url_).responseJSON { response in
res = response.result.value as! JSON
print("first result", res)
myGroup.leave()
}
myGroup.notify(queue: .main) {
print("Finished all requests.", res)
}
print("second result", res)
return res
}
But i have a problem with the line "res = response.result.value" wich gives me the error : Thread 1 : signal SIGABRT
I really don't understand where the problem comes from, it was pretty hard to do a "synchronous" function, maybe i'm doing it wrong.
My objective is to store the result of the request in a variable that i return. Anyone can help ?

Answer 1

I'd recommend you to use Alamofire together with SwiftyJSON because that way you'll be able to parse JSON easier a lot.
Here's a classical example:
Alamofire.request("http://example.net", method: .get).responseJSON { response in
switch response.result {
case .success(let value):
let json = JSON(value)
print("JSON: \(json)")
case .failure(let error):
print(error)
}
}
If you need to pass parameters, or headers, just add it in the request method.
let headers: HTTPHeaders = [
"Content-Type:": "application/json"
]
let parameters: [String: Any] = [
"key": "value"
]
So your request will be something like this (this is POST request):
Alamofire.request("http://example.net", method: .post, parameters: parameters, encoding: JSONEncoding.default, headers: headers).responseJSON { response in
switch response.result {
case .success(let value):
print(value)
case .failure(let error):
print(error)
}
}
I haven't tested it, but it should work. Also, you need to set allow arbitary load to yes (App Transport Security Settings in info.plist) if you want to allow requests over HTTP protocol.
This is NOT recommended, but it's fine for development.