How to make NSURLSession POST request in Swift

Question

Hi, I am starting very much for Swift, and I am trying to make an NSURLSession "Post" request by sending some parameter, for example, my code below

According to my answer below for code that doesn't come from the server, someone can help me.

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-

 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 answer, it is in Swift 4.0.

Here I prepared a coded 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 answered your answer correctly, pass it to your view dispatcher.

 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() } ytBQNu6A-Fw4pZBY" 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

Publication 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 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() } 

calling this method Like This

  self.post(["username":"jameson", "password":"password"], url: "http://localhost:4567/login") 

Hope this helps :)

Answer 4

Http is missing. Example - setting string parameters as a body

 let paramString = String(format:"param1=%@&param2=%@",param1,param2) request.httpBody = paramString.data(using: String.Encoding.utf8) 

just try

 request.httpBody = NSJSONSerialization.dataWithJSONObject(params, options: nil, error: &err) 

Answer 5

 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 6

Here is an example of a complete solution compatible with Swift 4 and Swift 5 .

Endpoint to create URL

 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 the 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 makes http requests to our APIs

 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 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() }