How to make NSURLSession POST request in Swift - ios

Question

Hi I am very beginner for Swift and I am trying to make NSURLSession "Post" request sending some parameter like my below code
According to my below code response not coming from server can some one help me please
BackGroundClass:-
import UIKit
protocol sampleProtocal{
func getResponse(result:NSDictionary)
func getErrorResponse(error:NSString)
}
class BackGroundClass: NSObject {
var delegate:sampleProtocal?
func callPostService(url:String,parameters:NSDictionary){
print("url is===>\(url)")
let request = NSMutableURLRequest(URL: NSURL(string:url)!)
let session = NSURLSession.sharedSession()
request.HTTPMethod = "POST"
//Note : Add the corresponding "Content-Type" and "Accept" header. In this example I had used the application/json.
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
request.addValue("application/json", forHTTPHeaderField: "Accept")
request.HTTPBody = try! NSJSONSerialization.dataWithJSONObject(parameters, options: [])
let task = session.dataTaskWithRequest(request) { data, response, error in
guard data != nil else {
print("no data found: \(error)")
return
}
do {
if let json = try NSJSONSerialization.JSONObjectWithData(data!, options: []) as? NSDictionary {
print("Response: \(json)")
self.mainResponse(json)
} else {
let jsonStr = NSString(data: data!, encoding: NSUTF8StringEncoding)// No error thrown, but not NSDictionary
print("Error could not parse JSON: \(jsonStr)")
self.eroorResponse(jsonStr!)
}
} catch let parseError {
print(parseError)// Log the error thrown by `JSONObjectWithData`
let jsonStr = NSString(data: data!, encoding: NSUTF8StringEncoding)
print("Error could not parse JSON: '\(jsonStr)'")
self.eroorResponse(jsonStr!)
}
}
task.resume()
}
func mainResponse(result:NSDictionary){
delegate?.getResponse(result)
}
func eroorResponse(result:NSString){
delegate?.getErrorResponse(result)
}
}
ViewController:-
import UIKit
class ViewController: UIViewController,sampleProtocal {
override func viewDidLoad() {
super.viewDidLoad()
let delegate = BackGroundClass();
delegate.self;
let params = ["scancode":"KK03799-008", "UserName":"admin"] as Dictionary<String, String>
let backGround=BackGroundClass();
backGround.callPostService("url", parameters: params)
}
func getResponse(result: NSDictionary) {
print("Final response is\(result)");
}
func getErrorResponse(error: NSString) {
print("Final Eroor code is\(error)")
}
}

Answer 1

Swift 4 post example with json payload-
func postAction(_ sender: Any) {
let Url = String(format: "your url")
guard let serviceUrl = URL(string: Url) else { return }
let parameterDictionary = ["username" : "Test", "password" : "123456"]
var request = URLRequest(url: serviceUrl)
request.httpMethod = "POST"
request.setValue("Application/json", forHTTPHeaderField: "Content-Type")
guard let httpBody = try? JSONSerialization.data(withJSONObject: parameterDictionary, options: []) else {
return
}
request.httpBody = httpBody
let session = URLSession.shared
session.dataTask(with: request) { (data, response, error) in
if let response = response {
print(response)
}
if let data = data {
do {
let json = try JSONSerialization.jsonObject(with: data, options: [])
print(json)
} catch {
print(error)
}
}
}.resume()
}

Answer 2

Try to run this function and print the response, it is in Swift 4.0.
Here, I have prepared codable structure:
struct LoginData: Codable {
var code: Int?
var message: String?
var status: String?
var token: String?
var data: DataSet?
}
struct DataSet: Codable {
var email : String?
var contactNo : String?
var firstName : String?
var lastName: String?
var dob : String?
var gender : String?
var address: String?
var city : String?
var state : String?
var country : String?
var zip : String?
var username: String?
}
If you get your response printed correctly then pass it to your viewController.
func loginWS(parameters:[String:String], completionHandler: #escaping (Any?) -> Swift.Void) {
guard let gitUrl = URL(string: BASE_URL+ACTION_URL) else { return }
print(gitUrl)
let request = NSMutableURLRequest(url: gitUrl)
// uncomment this and add auth token, if your project needs.
// let config = URLSessionConfiguration.default
// let authString = "Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1c2VyX2lkIjoxMywiUGFzc3dvcmQiOiIkMmEkMTAkYVhpVm9wU3JSLjBPYmdMMUk2RU5zdU9LQzlFR0ZqNzEzay5ta1pDcENpMTI3MG1VLzR3SUsiLCJpYXQiOjE1MTczOTc5MjV9.JaSh3FvpAxFxbq8z_aZ_4OhrWO-ytBQNu6A-Fw4pZBY"
// config.httpAdditionalHeaders = ["Authorization" : authString]
let session = URLSession.shared
request.httpMethod = "POST"
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
request.addValue("application/json", forHTTPHeaderField: "Accept")
request.httpBody = try! JSONSerialization.data(withJSONObject: parameters, options: [])
let task = session.dataTask(with: request as URLRequest) { data, response, error in
guard let data = data else { return }
do {
// let decoder = JSONDecoder()
// here replace LoginData with your codable structure.
let gitData = try JSONDecoder().decode(LoginData.self, from: data)
print("response data:", gitData)
completionHandler(gitData)
} catch let err {
print("Err", err)
}
}.resume()
}

Answer 3

Here is a sample complete solution compatible with Swift 4 and Swift 5.
Endpoint to create urls
struct Endpoint {
let path: String
let queryItems: [URLQueryItem]?
}
extension Endpoint {
var url: URL? {
var components = URLComponents()
components.scheme = "https"
components.host = "YOUR_HOST"
components.path = path
components.queryItems = queryItems
return components.url
}
}
User object model for request body
struct User: Encodable {
let name: String
let surname: String
let age: Int
// this is to customise init
init(name: String,
surname: String,
age: Int) {
self.name = name
self.surname = surname
self.age = age
}
enum CodingKeys: String, CodingKey {
case name, surname, age
}
}
UserResponse model for http response comes from API
struct UserResponse: Decodable {
let message: String
let userId: String?
enum CodingKeys: String, CodingKey {
case message, userId = "user_id" // API returns userId as "user_id"
}
}
APIClient make http requests for our api
protocol APIClientProtocol: Any {
func sendUser(_ user: User, completionBlock: #escaping (_ userResponse: UserResponse?, _ error: APIClient.Error?) -> Void)
}
class APIClient: APIClientProtocol {
fileprivate let defaultSession: URLSession = {
let configuration = URLSessionConfiguration.default
configuration.timeoutIntervalForRequest = 10.0
configuration.timeoutIntervalForResource = 10.0
return URLSession(configuration: configuration, delegate: nil, delegateQueue: nil)
}()
public init() { }
public func uploadUser(_ user: User, completionBlock: #escaping (UserResponse?, APIClient.Error?) -> Void) {
guard let url = Endpoint(path: "/user/upload", queryItems: nil).url else {
completionBlock(nil, .brokenURL)
return
}
var urlRequest = URLRequest(url: url)
urlRequest.httpMethod = "POST"
urlRequest.addValue("application/json", forHTTPHeaderField: "Content-Type")
urlRequest.addValue("application/json", forHTTPHeaderField: "Accept")
do {
let jsonData = try JSONEncoder().encode(user)
urlRequest.httpBody = jsonData
} catch {
completionBlock(nil, .serialization(error.localizedDescription))
return
}
let task = defaultSession.dataTask(with: urlRequest) { data, urlResponse, error in
if let error = error {
completionBlock(nil, .http(error.localizedDescription))
return
}
guard let httpResponse = urlResponse as? HTTPURLResponse else {
return
}
if httpResponse.statusCode == 200 {
guard let data = data else {
return
}
do {
let userResponse = try JSONDecoder().decode(UserResponse.self, from: data)
completionBlock(userResponse, nil)
} catch let error {
completionBlock(nil, .serialization(error.localizedDescription))
}
} else {
completionBlock(nil, .http("Status failed!"))
}
}
task.resume()
}
}
extension APIClient {
enum Error: Swift.Error, Equatable {
case brokenURL
case serialization(String)
case http(String)
}
}

Answer 4

Post Class
func post(params : Dictionary<String, String>, url : String) {
var request = NSMutableURLRequest(URL: NSURL(string: url))
var session = NSURLSession.sharedSession()
request.HTTPMethod = "POST"
var err: NSError?
request.HTTPBody = NSJSONSerialization.dataWithJSONObject(params, options: nil, error: &err)
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
request.addValue("application/json", forHTTPHeaderField: "Accept")
var task = session.dataTaskWithRequest(request, completionHandler: {data, response, error -> Void in
println("Response: \(response)")
var strData = NSString(data: data, encoding: NSUTF8StringEncoding)
println("Body: \(strData)")
var err: NSError?
var json = NSJSONSerialization.JSONObjectWithData(data, options: .MutableLeaves, error: &err) as? NSDictionary
// Did the JSONObjectWithData constructor return an error? If so, log the error to the console
if(err != nil) {
println(err!.localizedDescription)
let jsonStr = NSString(data: data, encoding: NSUTF8StringEncoding)
println("Error could not parse JSON: '\(jsonStr)'")
}
else {
// The JSONObjectWithData constructor didn't return an error. But, we should still
// check and make sure that json has a value using optional binding.
if let parseJSON = json {
// Okay, the parsedJSON is here, let's get the value for 'success' out of it
var success = parseJSON["success"] as? Int
println("Succes: \(success)")
}
else {
// Woa, okay the json object was nil, something went worng. Maybe the server isn't running?
let jsonStr = NSString(data: data, encoding: NSUTF8StringEncoding)
println("Error could not parse JSON: \(jsonStr)")
}
}
})
task.resume()
}
call This Method Like This
self.post(["username":"jameson", "password":"password"], url: "http://localhost:4567/login")
Hope It Helps :)

Answer 5

Http body is missing. Example - setting string paramets as body
let paramString = String(format:"param1=%#&param2=%#",param1,param2)
request.httpBody = paramString.data(using: String.Encoding.utf8)
here just try
request.httpBody = NSJSONSerialization.dataWithJSONObject(params, options: nil, error: &err)

Answer 6

func getData(searchString:String,completion:#escaping(Any)->Void){
let url = "https://itunes.apple.com/search?term="+searchString
URLSession.shared.dataTask(with: URL.init(string: url)!){(data,response,err) in
if let responsedata = data{
DispatchQueue.main.async {
completion(responsedata)
}
}
}.resume()
}

Answer 7

Try this: (Swift 4.2)
public func submitDelivery(delivery:DeliveryModal,responseCode:String,completion:#escaping SubmitCompletionBlock){
let urlString = BaseURL.getURL(urlType: .submit(responseCode))
guard let url = URL(string: urlString) else { return }
var request : URLRequest = URLRequest(url: url)
request.httpMethod = HttpMethod.post.rawValue
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
request.addValue("application/json", forHTTPHeaderField: "Accept")
let encoder = JSONEncoder()
encoder.outputFormatting = .prettyPrinted
do {
let jsonData = try encoder.encode(delivery)
request.httpBody = jsonData
} catch {
print(error.localizedDescription)
completion(nil,nil,NSError.init())
}
let dataTask = URLSession.shared.dataTask(with: request) {
data,response,error in
guard let data = data else {
completion(nil,response,NSError.init())
return
}
do {
let data = try JSONDecoder().decode(DeliverySubmitResponseModal.self, from: data)
DispatchQueue.main.async {
completion(data,response,error)
}
} catch let error {
debugPrint(error.localizedDescription)
}
}
dataTask.resume()
}