Make a REST API call in Swift

Question

I am trying to use Swift to make a GET call to the REST API, and tried to follow numerous tutorials, but can't figure it out. Either because I can't figure out how to translate all of Obj-C into Swift, or because half of the n 'methods are deprecated. Does anyone know how to make a call and parse JSON data?

Answer 1

You can do the following:

var url : String = "http://google.com?test=toto&test2=titi" var request : NSMutableURLRequest = NSMutableURLRequest() request.URL = NSURL(string: url) request.HTTPMethod = "GET" NSURLConnection.sendAsynchronousRequest(request, queue: NSOperationQueue(), completionHandler:{ (response:NSURLResponse!, data: NSData!, error: NSError!) -> Void in var error: AutoreleasingUnsafeMutablePointer<NSError?> = nil let jsonResult: NSDictionary! = NSJSONSerialization.JSONObjectWithData(data, options:NSJSONReadingOptions.MutableContainers, error: error) as? NSDictionary if (jsonResult != nil) { // process jsonResult } else { // couldn't load JSON, look at error } }) 

EDIT: people have problems with this, maybe your JSON stream is an array [], not an {} object, so you need to change jsonResult to NSArray instead of NSDictionary

Answer 2

I think the NSURLSession api is better suited in this situation. Because if you write fast code, the goal of your project is at least iOS 7, and iOS 7 supports NSURLSession api. Anyway here is the code

 let url = "YOUR_URL" NSURLSession.sharedSession().dataTaskWithURL(NSURL(string: url)) { data, response, error in // Handle result }.resume() 

Answer 3

Here is the complete code for REST API requests using NSURLSession in swift

 For GET Request let configuration = NSURLSessionConfiguration .defaultSessionConfiguration() let session = NSURLSession(configuration: configuration) let urlString = NSString(format: "your URL here") print("get wallet balance url string is \(urlString)") //let url = NSURL(string: urlString as String) let request : NSMutableURLRequest = NSMutableURLRequest() request.URL = NSURL(string: NSString(format: "%@", urlString) as String) request.HTTPMethod = "GET" request.timeoutInterval = 30 request.addValue("application/json", forHTTPHeaderField: "Content-Type") request.addValue("application/json", forHTTPHeaderField: "Accept") let dataTask = session.dataTaskWithRequest(request) { (let data: NSData?, let response: NSURLResponse?, let error: NSError?) -> Void in // 1: Check HTTP Response for successful GET request guard let httpResponse = response as? NSHTTPURLResponse, receivedData = data else { print("error: not a valid http response") return } switch (httpResponse.statusCode) { case 200: let response = NSString (data: receivedData, encoding: NSUTF8StringEncoding) print("response is \(response)") do { let getResponse = try NSJSONSerialization.JSONObjectWithData(receivedData, options: .AllowFragments) EZLoadingActivity .hide() // } } catch { print("error serializing JSON: \(error)") } break case 400: break default: print("wallet GET request got response \(httpResponse.statusCode)") } } dataTask.resume() 

For a POST request ...

 let configuration = NSURLSessionConfiguration .defaultSessionConfiguration() let session = NSURLSession(configuration: configuration) let params = ["username":bindings .objectForKey("username"), "provider":"walkingcoin", "securityQuestion":securityQuestionField.text!, "securityAnswer":securityAnswerField.text!] as Dictionary<String, AnyObject> let urlString = NSString(format: "your URL"); print("url string is \(urlString)") let request : NSMutableURLRequest = NSMutableURLRequest() request.URL = NSURL(string: NSString(format: "%@", urlString)as String) request.HTTPMethod = "POST" request.timeoutInterval = 30 request.addValue("application/json", forHTTPHeaderField: "Content-Type") request.addValue("application/json", forHTTPHeaderField: "Accept") request.HTTPBody = try! NSJSONSerialization.dataWithJSONObject(params, options: []) let dataTask = session.dataTaskWithRequest(request) { (let data: NSData?, let response: NSURLResponse?, let error: NSError?) -> Void in // 1: Check HTTP Response for successful GET request guard let httpResponse = response as? NSHTTPURLResponse, receivedData = data else { print("error: not a valid http response") return } switch (httpResponse.statusCode) { case 200: let response = NSString (data: receivedData, encoding: NSUTF8StringEncoding) if response == "SUCCESS" { } default: print("save profile POST request got response \(httpResponse.statusCode)") } } dataTask.resume() 

I hope this works.

Answer 4

Swift 5 and 4

 let params = ["username":"john", "password":"123456"] as Dictionary<String, String> var request = URLRequest(url: URL(string: "http://localhost:8080/api/1/login")!) request.httpMethod = "POST" request.httpBody = try? JSONSerialization.data(withJSONObject: params, options: []) request.addValue("application/json", forHTTPHeaderField: "Content-Type") let session = URLSession.shared let task = session.dataTask(with: request, completionHandler: { data, response, error -> Void in print(response!) do { let json = try JSONSerialization.jsonObject(with: data!) as! Dictionary<String, AnyObject> print(json) } catch { print("error") } }) task.resume() 

Answer 5

edited for swift 2

 let url = NSURL(string: "http://www.test.com") let task = NSURLSession.sharedSession().dataTaskWithURL(url!) {(data, response, error) in print(NSString(data: data!, encoding: NSUTF8StringEncoding)) } task.resume() 

Answer 6

Swift 4 - GET request

 var request = URLRequest(url: URL(string: "http://example.com/api/v1/example")!) request.httpMethod = "GET" URLSession.shared.dataTask(with: request, completionHandler: { data, response, error -> Void in do { let jsonDecoder = JSONDecoder() let responseModel = try jsonDecoder.decode(CustomDtoClass.self, from: data!) print(responseModel) } catch { print("JSON Serialization error") } }).resume() 

Remember to configure the application’s transport security settings to add your domain to exceptions and allow unsafe http requests if you use endpoints without using HTTPS.

You can use a tool like http://www.json4swift.com/ to automatically generate your encoded mappings from your JSON responses.

Answer 7

Swift 3.0

 let request = NSMutableURLRequest(url: NSURL(string: "http://httpstat.us/200")! as URL) let session = URLSession.shared request.httpMethod = "GET" request.addValue("application/json", forHTTPHeaderField: "Content-Type") request.addValue("application/json", forHTTPHeaderField: "Accept") let task = session.dataTask(with: request as URLRequest, completionHandler: {data, response, error -> Void in if error != nil { print("Error: \(String(describing: error))") } else { print("Response: \(String(describing: response))") } }) task.resume() 

Answer 8

Swift 4

Build an app using Alamofire with the Api Post method

Install pod file -pod 'Alamofire', '~> 4.0' for Swift 3 with Xcode 9

Create class Webservices.swift, import Alamofire

Design scenario, login view

paste the following code for ViewControllerClass

 import UIKit class ViewController: UIViewController { @IBOutlet var usernameTextField: UITextField! @IBOutlet var passwordTextField: UITextField! var usertypeStr :String = "-----------" var loginDictionary : NSDictionary? override func viewDidLoad() { super.viewDidLoad() // Do any additional setup after loading the view, typically from a nib. } override func didReceiveMemoryWarning() { super.didReceiveMemoryWarning() // Dispose of any resources that can be recreated. } @IBAction func loginButtonClicked(_ sender: Any) { WebServices.userLogin(userName: usernameTextField.text!, password: passwordTextField.text!,userType: usertypeStr) {(result, message, status )in if status { let loginDetails = result as? WebServices self.loginDictionary = loginDetails?.loginData if self.loginDictionary?["status"] as? String == "error" { self.alertMessage(alerttitle: "Login Error", (self.loginDictionary?["message"] as? String)!) } else if self.loginDictionary?["status"] as? String == "ok" { self.alertMessage(alerttitle: "", "Success") }else { self.alertMessage(alerttitle: "", (self.loginDictionary?["message"] as? String)!) } } else { self.alertMessage(alerttitle: "", "Sorry") } } } func alertMessage(alerttitle:String,_ message : String){ let alertViewController = UIAlertController(title:alerttitle, message:message, preferredStyle: .alert) alertViewController.addAction(UIAlertAction(title: "OK", style: .default, handler: nil)) present(alertViewController, animated: true, completion: nil) } } 

Paste the following code for WebserviceClass

 import Foundation import Alamofire class WebServices: NSObject { enum WebServiceNames: String { case baseUrl = "https://---------------" case UserLogin = "------------" } // MARK: - Login Variables var loginData : NSDictionary? class func userLogin(userName: String,password : String,userType : String, completion : @escaping (_ response : AnyObject?, _ message: String?, _ success : Bool)-> ()) { let url = WebServiceNames.baseUrl.rawValue + WebServiceNames.UserLogin.rawValue let params = ["USER": userName,"PASS":password,"API_Key" : userType] WebServices.postWebService(urlString: url, params: params as [String : AnyObject]) { (response, message, status) in print(response ?? "Error") let result = WebServices() if let data = response as? NSDictionary { print(data) result.loginData = data completion(result, "Success", true) }else { completion("" as AnyObject?, "Failed", false) } } } //MARK :- Post class func postWebService(urlString: String, params: [String : AnyObject], completion : @escaping (_ response : AnyObject?, _ message: String?, _ success : Bool)-> Void) { alamofireFunction(urlString: urlString, method: .post, paramters: params) { (response, message, success) in if response != nil { completion(response as AnyObject?, "", true) }else{ completion(nil, "", false) } } } class func alamofireFunction(urlString : String, method : Alamofire.HTTPMethod, paramters : [String : AnyObject], completion : @escaping (_ response : AnyObject?, _ message: String?, _ success : Bool)-> Void){ if method == Alamofire.HTTPMethod.post { Alamofire.request(urlString, method: .post, parameters: paramters, encoding: URLEncoding.default, headers: nil).responseJSON { (response:DataResponse<Any>) in print(urlString) if response.result.isSuccess{ completion(response.result.value as AnyObject?, "", true) }else{ completion(nil, "", false) } } }else { Alamofire.request(urlString).responseJSON { (response) in if response.result.isSuccess{ completion(response.result.value as AnyObject?, "", true) }else{ completion(nil, "", false) } } } } //Mark:-Cancel class func cancelAllRequests() { Alamofire.SessionManager.default.session.getTasksWithCompletionHandler { dataTasks, uploadTasks, downloadTasks in dataTasks.forEach { $0.cancel() } uploadTasks.forEach { $0.cancel() } downloadTasks.forEach { $0.cancel() } } } } 

Answer 9

If you are working in Swift 3, the syntax changes. The example here worked for me and has a good explanation of the steps: https://grokswift.com/simple-rest-with-swift/

This is the code from this tutorial:

 let todoEndpoint: String = "https://jsonplaceholder.typicode.com/todos/1" guard let url = URL(string: todoEndpoint) else { print("Error: cannot create URL") return } let urlRequest = URLRequest(url: url) let task = session.dataTask(with: urlRequest) { (data, response, error) in // check for any errors guard error == nil else { print("error calling GET on /todos/1") print(error!) return } // make sure we got data guard let responseData = data else { print("Error: did not receive data") return } // parse the result as JSON, since that what the API provides do { guard let todo = try JSONSerialization.jsonObject(with: responseData, options: []) as? [String: Any] else { print("error trying to convert data to JSON") return } // now we have the todo // let just print it to prove we can access it print("The todo is: " + todo.description) // the todo object is a dictionary // so we just access the title using the "title" key // so check for a title and print it if we have one guard let todoTitle = todo["title"] as? String else { print("Could not get todo title from JSON") return } print("The title is: " + todoTitle) } catch { print("error trying to convert data to JSON") return } } task.resume() 

Answer 10

fast 4

USE ALAMOFIRE in our app file plz install pod

pod 'Alamofire', '~> 4.0'

We can use the API for Json Data - https://swapi.co/api/people/

Then we can create a network class for our project-networkingService.swift

 import Foundation import Alamofire typealias JSON = [String:Any] class networkingService{ static let shared = networkingService() private init() {} func getPeople(success successblock: @escaping (GetPeopleResponse) -> Void) { Alamofire.request("https://swapi.co/api/people/").responseJSON { response in guard let json = response.result.value as? JSON else {return} // print(json) do { let getPeopleResponse = try GetPeopleResponse(json: json) successblock(getPeopleResponse) }catch{} } } func getHomeWorld(homeWorldLink:String,completion: @escaping(String) ->Void){ Alamofire.request(homeWorldLink).responseJSON {(response) in guard let json = response.result.value as? JSON, let name = json["name"] as? String else{return} completion(name) } } } 

Then create the NetworkingError.swift class

 import Foundation enum networkingError : Error{ case badNetworkigStuff } 

Then create the Person.swift class

 import Foundation struct Person { private let homeWorldLink : String let birthyear : String let gender : String let haircolor : String let eyecolor : String let height : String let mass : String let name : String let skincolor : String init?(json : JSON) { guard let birthyear = json["birth_year"] as? String, let eyecolor = json["eye_color"] as? String, let gender = json["gender"] as? String, let haircolor = json["hair_color"] as? String, let height = json["height"] as? String, let homeWorldLink = json["homeworld"] as? String, let mass = json["mass"] as? String, let name = json["name"] as? String, let skincolor = json["skin_color"] as? String else { return nil } self.homeWorldLink = homeWorldLink self.birthyear = birthyear self.gender = gender self.haircolor = haircolor self.eyecolor = eyecolor self.height = height self.mass = mass self.name = name self.skincolor = skincolor } func homeWorld(_ completion: @escaping (String) -> Void) { networkingService.shared.getHomeWorld(homeWorldLink: homeWorldLink){ (homeWorld) in completion(homeWorld) } } } 

Then create DetailVC.swift

 import UIKit class DetailVC: UIViewController { var person :Person! @IBOutlet var name: UILabel! @IBOutlet var birthyear: UILabel! @IBOutlet var homeworld: UILabel! @IBOutlet var eyeColor: UILabel! @IBOutlet var skinColor: UILabel! @IBOutlet var gender: UILabel! @IBOutlet var hairColor: UILabel! @IBOutlet var mass: UILabel! @IBOutlet var height: UILabel! override func viewDidLoad() { super.viewDidLoad() print(person) name.text = person.name birthyear.text = person.birthyear eyeColor.text = person.eyecolor gender.text = person.gender hairColor.text = person.haircolor mass.text = person.mass height.text = person.height skinColor.text = person.skincolor person.homeWorld{(homeWorld) in self.homeworld.text = homeWorld } } } 

Then create the GetPeopleResponse.swift class

 import Foundation struct GetPeopleResponse { let people : [Person] init(json :JSON) throws { guard let results = json["results"] as? [JSON] else { throw networkingError.badNetworkigStuff} let people = results.map{Person(json: $0)}.flatMap{ $0 } self.people = people } } 

Then the View View controller class

 import UIKit class ViewController: UIViewController { @IBOutlet var tableVieww: UITableView! var people = [Person]() @IBAction func getAction(_ sender: Any) { print("GET") networkingService.shared.getPeople{ response in self.people = response.people self.tableVieww.reloadData() } } override func prepare(for segue: UIStoryboardSegue, sender: Any?) { guard segue.identifier == "peopleToDetails", let detailVC = segue.destination as? DetailVC, let person = sender as AnyObject as? Person else {return} detailVC.person = person } } extension ViewController:UITableViewDataSource{ func numberOfSections(in tableView: UITableView) -> Int { return 1 } func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int { return people.count } func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell { let cell = UITableViewCell() cell.textLabel?.text = people[indexPath.row].name return cell } } extension ViewController:UITableViewDelegate{ func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) { performSegue(withIdentifier: "peopleToDetails", sender: people[indexPath.row]) } } 

In our storyboard

plz Connect to our view with another using segue with the identifier -peopleToDetails

• Using UITableView in our first view

• Using UIButton To Get Data

• Use 9 shortcuts in our DetailVc

Answer 11

In swift 3.3 and 4. I created the APIManager class with two public methods. Just pass the required parameter, API name and request type. You will receive an answer, then forward it to closing.

  import UIKit struct RequestType { static let POST = "POST" static let GET = "GET" } enum HtttpType: String { case POST = "POST" case GET = "GET" } class APIManager: NSObject { static let sharedInstance: APIManager = { let instance = APIManager() return instance }() private init() {} // First Method public func requestApiWithDictParam(dictParam: Dictionary<String,Any>, apiName: String,requestType: String, isAddCookie: Bool, completionHendler:@escaping (_ response:Dictionary<String,AnyObject>?, _ error: NSError?, _ success: Bool)-> Void) { var apiUrl = "" // Your api url apiUrl = apiUrl.appendingFormat("%@", apiName) let config = URLSessionConfiguration.default let session = URLSession(configuration: config) let url = URL(string: apiUrl)! let HTTPHeaderField_ContentType = "Content-Type" let ContentType_ApplicationJson = "application/json" var request = URLRequest.init(url: url) request.timeoutInterval = 60.0 request.cachePolicy = URLRequest.CachePolicy.reloadIgnoringLocalCacheData request.addValue(ContentType_ApplicationJson, forHTTPHeaderField: HTTPHeaderField_ContentType) request.httpMethod = requestType print(apiUrl) print(dictParam) let dataTask = session.dataTask(with: request) { (data, response, error) in if error != nil { completionHendler(nil, error as NSError?, false) } do { let resultJson = try JSONSerialization.jsonObject(with: data!, options: []) as? [String:AnyObject] print("Request API = ", apiUrl) print("API Response = ",resultJson ?? "") completionHendler(resultJson, nil, true) } catch { completionHendler(nil, error as NSError?, false) } } dataTask.resume() } // Second Method public func requestApiWithUrlString(param: String, apiName: String,requestType: String, isAddCookie: Bool, completionHendler:@escaping (_ response:Dictionary<String,AnyObject>?, _ error: NSError?, _ success: Bool)-> Void ) { var apiUrl = "" // Your api url let config = URLSessionConfiguration.default let session = URLSession(configuration: config) var request: URLRequest? if requestType == "GET" { apiUrl = String(format: "%@%@&%@", YourAppBaseUrl,apiName,param) apiUrl = apiUrl.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed)! print("URL=",apiUrl) let url = URL(string: apiUrl)! request = URLRequest.init(url: url) request?.httpMethod = "GET" } else { apiUrl = String(format: "%@%@", YourAppBaseUrl,apiName) apiUrl = apiUrl.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed)! print("URL=",apiUrl) let bodyParameterData = param.data(using: .utf8) let url = URL(string: apiUrl)! request = URLRequest(url: url) request?.httpBody = bodyParameterData request?.httpMethod = "POST" } request?.timeoutInterval = 60.0 request?.cachePolicy = URLRequest.CachePolicy.reloadIgnoringLocalCacheData request?.httpShouldHandleCookies = true let dataTask = session.dataTask(with: request!) { (data, response, error) in if error != nil { completionHendler(nil, error as NSError?, false) } do { if data != nil { let resultJson = try JSONSerialization.jsonObject(with: data!, options: []) as? [String:AnyObject] print("Request API = ", apiUrl) print("API Response = ",resultJson ?? "") completionHendler(resultJson, nil, true) } else { completionHendler(nil, error as NSError?, false) } } catch { completionHendler(nil, error as NSError?, false) } } dataTask.resume() } } // Here is example of calling Post API from any class let bodyParameters = String(format: "appid=%@&appversion=%@","1","1") APIManager.sharedInstance.requestApiWithUrlString(param: bodyParameters, apiName: "PASS_API_NAME", requestType: HtttpType.POST.rawValue, isAddCookie: false) { (dictResponse, error, success) in if success { if let dictMessage = dictResponse?["message"] as? Dictionary<String, AnyObject> { // do you work } } else { print("Something went wrong...") } } } /// Or just use simple function func dataRequest() { let urlToRequest = "" // Your API url let url = URL(string: urlToRequest)! let session4 = URLSession.shared let request = NSMutableURLRequest(url: url) request.httpMethod = "POST" request.cachePolicy = NSURLRequest.CachePolicy.reloadIgnoringCacheData let paramString = "data=Hello" request.httpBody = paramString.data(using: String.Encoding.utf8) let task = session4.dataTask(with: request as URLRequest) { (data, response, error) in guard let _: Data = data, let _: URLResponse = response, error == nil else { print("*****error") return } if let dataString = NSString(data: data!, encoding: String.Encoding.utf8.rawValue) { print("****Data: \(dataString)") //JSONSerialization } } task.resume() } 

Answer 12

Api Call using the model class

  let urlString = "http://--.154.--.78/------/index.php?route=api/coupon/all" let url = URL(string: urlString) var request = URLRequest(url: url!) request.httpMethod = "GET" URLSession.shared.dataTask(with:request) { (data, response, error) in if error != nil { print(error) } else { do { let parsedDictionaryArray = try JSONSerialization.jsonObject(with: data!) as! [String:AnyObject] print(parsedDictionaryArray) if let arry = parsedDictionaryArray["data"] as? [[String:AnyObject]] { for dic in arry { let name = dic["name"] let descriptionData = dic["description"] self.modelReference.append(model(name: name as! String, descriptionStr: descriptionData as! String)) print(name!) } } } catch let error as NSError { print(error) } } }.resume() 

create a variable and contact the model class

 var modelReference = [model]() 

create a model class New → swift class

 import Foundation class model : NSObject{ var name : String var descriptionStr: String init(name : String, descriptionStr: String) { self.name = name self.descriptionStr = descriptionStr } 

}

then we can connect to our table view objects

 let cell = tableView.dequeueReusableCell(withIdentifier: "TableViewCellID")as! TableViewCell cell.listName.text = modelReference[indexPath.row].name 

Answer 13

 let headers = [ "cache-control": "no-cache", "postman-token": "6f8a-12c6-87a1-ac0f25d6385a" ] let request = NSMutableURLRequest(url: NSURL(string: "Your url string")! as URL, cachePolicy: .useProtocolCachePolicy, timeoutInterval: 10.0) request.httpMethod = "GET" request.allHTTPHeaderFields = headers let session = URLSession.shared let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in if error == nil && data != nil { do { // Convert NSData to Dictionary where keys are of type String, and values are of any type let json = try JSONSerialization.jsonObject(with: data!, options: JSONSerialization.ReadingOptions.mutableContainers) as! [String:AnyObject] print(json) //do your stuff // completionHandler(true) } catch { // completionHandler(false) } } else if error != nil { //completionHandler(false) } }).resume() }