ios - How to wait api response using Alamofire - ios

Question

I want to ask about Semaphore in Alamofire.
I want the app wait for data from the server return success and continue to execute the code after (synchronous type). I use semaphore, but when the api function is called, the app is suspended...
This code is call data from server:
func getAllModels() -> [String] {
var _modelList:[String] = []
let url = BASE_URL + "getAllProductAndModelv2"
let semaphore = DispatchSemaphore(value: 0)
Alamofire.request(url, method:.get, parameters: [:], encoding: JSONEncoding.default).responseJSON { response in
let data = NSData(contentsOf: URL(string: url)!)
do {
if let data = data, let json = try JSONSerialization.jsonObject(with: data as Data) as? [String: Any], let models = json["models"] as? [[String:Any]] {
for model in models {
if let name = model["name"] as? String {
_modelList.append(name)
}
}
}
}catch {
print("error")
}
semaphore.signal()
}
semaphore.wait()
return _modelList
}
And this code is going to get the result:
let api = RestApiManager()
var result:[String] = api.getAllModels()
print(result)
How to relsove this issuse?
Thank you

Answer 1

Use completion
func getAllModels( completion: #escaping ([String] ,Bool) -> Void) {
var modelList:[String] = []
let url = BASE_URL + "getAllProductAndModelv2"
Alamofire.request(url, method:.get, parameters: [:], encoding: JSONEncoding.default).responseJSON { response in
let data = NSData(contentsOf: URL(string: url)!)
do {
if let data = data, let json = try JSONSerialization.jsonObject(with: data as Data) as? [String: Any], let models = json["models"] as? [[String:Any]] {
for model in models {
if let name = model["name"] as? String {
modelList.append(name)
}
}
completion(modelList,true)
}
}catch {
print("error")
completion([],false)
}
}
}
Then call it
self.getAllModels { (data, success) in
if(success)
{
// use data
}
}