can not get access token from api - ios

Question

enter image description hereI'm new to Swift and I just faced a problem . any help and suggestion is welcome, also i've seen Alomofire, but I was not able to setup Alamofire because of some errors, and Also I need help in Alamofire :|
request.addValue("application/json", forHTTPHeaderField:
"Accept")
request.addValue("application/x-www-form-urlencoded",
forHTTPHeaderField: "Content-Type")
let postString = ["grant_type" : "password" ,
"username" : EntPhoneNumber.text! ,
"password" : EntPassword.text! ,] as [String :
Any]
do {
request.httpBody = try JSONSerialization.data(withJSONObject:
postString)
}catch let error {
print(error.localizedDescription)
DisplayMessage(UserMessage: "Something went wrong , please try
again!")
return
}
let task = URLSession.shared.dataTask(with: request)
{
(data : Data? , response : URLResponse? , error : Error?) in
self.removeActivtyIndicator(activityIndicator:
MyActivityIndicator)
if error != nil
{
self.DisplayMessage(UserMessage: "1Could not successfully
perform this request , please try again later.")
print("error = \(String(describing : error))")
return
}
// let's convert response sent from a server side code to a
NSDictionary object:
do { let json = try JSONSerialization.jsonObject(with: data!,
options: .mutableContainers) as? NSDictionary
print(json!)
if let parseJSON = json
{
let userID = parseJSON["grant_type"] as? String
print("access_token : \(String(describing: userID))");
if userID == nil
{
//display an alert dialog with a friendly error
message
self.DisplayMessage(UserMessage: "2Could not
successfully perform this request , please try later.")
return
}
else
{
self.DisplayMessage(UserMessage: "3successfully
loged in.")
}
}
...
as you can see this is my code which i'm posting a request to api to get an access_token but i receive an error :
{error = "invalid_request";
"error_description" = "The mandatory 'grant_type' parameter is missing.";
}
These are the parameters that I should post to API and in postman it works properly but my code does not work at all in compiler.

Answer 1

you are making it too complex
let postString = ["grant_type" : "password" ,
"username" : EntPhoneNumber.text! ,
"password" : EntPassword.text! ,] as [String :
Any]
Alamofire.request(URL, method: .post, parameters: postString, encoding: URLEncoding.methodDependent, headers: nil).responseJSON { response in
if let json = response.result.value {
print("Response: ",json)
}
}
try this.
This is all you need. If you have any doubt ask here.

Answer 2

Follow this link to install Alamofire using CocoaPods
https://www.raywenderlich.com/156971/cocoapods-tutorial-swift-getting-startedenter link description here
I have created this custom method for API request.
func request(_ method: HTTPMethod
, _ URLString: String
, parameters: [String : AnyObject]? = [:]
, headers: [String : String]? = [:]
, completion:#escaping (Any?) -> Void
, failure: #escaping (Error?) -> Void) {
Alamofire.request(URLString, method: method, parameters: parameters, encoding: JSONEncoding.default, headers: headers)
.responseJSON { response in
switch response.result {
case .success:
completion(response.result.value!)
case .failure(let error):
failure(error)
}
}
}

Answer 3

You need to encode the login and password parameters in query while sending the request. Lets create a separate Network class which has loginRequest(username:password) function which makes the API request to the server with username and password params. The login method has a closure which either returns a userId string or Error.
class Networking {
enum NetworkError: Error {
case parsingData
case jsonParsing
case emptyData
case apiError(error: Error)
}
func parseJSON(from data: Data) throws -> Any {
do {
let json = try JSONSerialization.jsonObject(with: data, options: .allowFragments)
return json
} catch {
return error
}
}
func loginRequest(username: String, password: String, completion: #escaping (String?, NetworkError?) -> ()) {
var request = URLRequest(url: URL(string: "api.nahadeh.com/connect/token")!)
request.addValue("application/json", forHTTPHeaderField: "Accept")
request.addValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
let queryParams = "grant_type=password&username=\(username)&password=\(password)"
request.httpBody = queryParams.data(using: .utf8, allowLossyConversion: false)
URLSession.shared.dataTask(with: request) { (data, response, error) in
guard error != nil else {
completion(nil, NetworkError.apiError(error: error!))
return
}
guard let data = data else {
return completion(nil, NetworkError.emptyData)
}
do {
let json = try self.parseJSON(from: data) as! [String: Any]
guard let accessToken = json["access_token"] as? String else {
completion(nil, NetworkError.jsonParsing)
return
}
completion(accessToken, nil)
} catch {
completion(nil, NetworkError.jsonParsing)
}
}.resume()
}
}
Now from your UIViewController subclass you can create the instance of Networking class and call the login method with username and password params
class LoginViewController: UIViewController {
let networking = Networking()
func login(username: String, password: String) {
networking.loginRequest(username: username, password: password) { (token, error) in
if let token = token {
print(token)
self.displayMessage("Successfully loged in. Go to home screen")
return
}
if let nError = error {
switch nError {
case .jsonParsing:
self.displayMessage("jsonParsingError")
case .emptyData:
self.displayMessage("emptyData")
case .apiError(let error):
print(error.localizedDescription)
self.displayMessage("Could not successfully perform this request , please try later.")
case .parsingData:
self.displayMessage("parsingData")
}
}
}
}
func displayMessage(_ message: String, completion: (() -> Void)? = nil) {
let alert = UIAlertController(title: "Message", message: message, preferredStyle: .alert)
let okAction = UIAlertAction(title: "OK", style: .default, handler: nil)
alert.addAction(okAction)
present(alert, animated: true, completion: completion)
}
}
Using Alamofire it's very easy to make API request, just pass the params and it will do the work for you
func loginRequest(username: String, password: String, completion: #escaping (String?, Error?) -> ()) {
let params: [String: String] = [
"grant_id": "password",
"username": username,
"password" : password
]
Alamofire.request("api.nahadeh.com/connect/token", method: .post, parameters: params, encoding: .httpBody, headers: nil).validate().response { (response) in
switch response.result {
case .success(let value):
let accessToken = value["access_token"]
completion(accessToken, nil)
case .failure(let error):
completion(nil, error)
}
}
}