Swift Alamofire Async Issue - swift

Question

new to swift here.
I'm trying to make an AF.request call inside another AF.request call and everything works fine.
The issue is that the fetchAllUsers() gets called after everything loads up. So instead of getting all the users right away, I have to refresh the page in order to get the fetchAllUsers() to execute.
I thought using closures would avoid this problem but it's still occurring.
Am I doing something wrong?
func fetchAllUsers(completionHandler: #escaping ([User]) -> Void) {
let allUsersUrl = baseUrl + "users/"
let headers: HTTPHeaders = [
.authorization(bearerToken: NetworkManager.authToken)
]
if let url = URL(string: allUsersUrl) {
AF.request(url, headers: headers).responseDecodable(of: [User].self) { response in
if let users = response.value {
completionHandler(users)
} else {
print("Users is empty")
}
}
} else {
print("URL error")
}
}
func login(param: [String:String], completionHandler: #escaping (Int) -> Void) {
let loginUrl = baseUrl + "auth/login"
// Sets the Logged In User
AF.request(loginUrl, method: .post, parameters: param, encoding: JSONEncoding.default, headers: nil).responseString { response in
if let data = response.data {
let authTokenString = String(decoding: data, as:UTF8.self).components(separatedBy: " ")
// Sets the authentication token
NetworkManager.authToken = authTokenString[1]
self.fetchAllUsers { users in
for user in users {
if param["username"] == user.username {
HomeViewModel.loggedInUser = user
}
}
}
completionHandler(response.response!.statusCode)
}
}
}

Answer 1

Pass completion handler of main function and status code to fetchAllUsers and call it there after it's own completion handler
completionHandler(response.response!.statusCode) was being executed before self.fetchAllUsers closure because it was waiting for api response to complete. completionHandler(response.response!.statusCode) was destroying self.fetchAllUsers closure before it is executed, so I called completionHandler(response.response!.statusCode) inside self.fetchAllUsers after it's closure
completionHandler(users)
mainCompletion(statusCode)
Complete code works following
func fetchAllUsers(statusCode:Int, mainCompletion: #escaping (Int) -> Void, completionHandler: #escaping ([User]) -> Void) {
let allUsersUrl = baseUrl + "users/"
let headers: HTTPHeaders = [
.authorization(bearerToken: NetworkManager.authToken)
]
if let url = URL(string: allUsersUrl) {
AF.request(url, headers: headers).responseDecodable(of: [User].self) { response in
if let users = response.value {
completionHandler(users)
mainCompletion(statusCode)
} else {
print("Users is empty")
}
}
} else {
print("URL error")
}
}
func login(param: [String:String], completionHandler: #escaping (Int) -> Void) {
let loginUrl = baseUrl + "auth/login"
// Sets the Logged In User
AF.request(loginUrl, method: .post, parameters: param, encoding: JSONEncoding.default, headers: nil).responseString { response in
if let data = response.data {
let authTokenString = String(decoding: data, as:UTF8.self).components(separatedBy: " ")
// Sets the authentication token
NetworkManager.authToken = authTokenString[1]
self.fetchAllUsers(statusCode: response.response!.statusCode, mainCompletion: completionHandler) { users in
for user in users {
if param["username"] == user.username {
HomeViewModel.loggedInUser = user
}
}
}
}
}
}