I'm just learning Web APIs with Swift.
And I've done as follows
Make some basic configuration
let session = URLSession(configuration: .default)
// Prepare URL #the URL is virtual now
let url = URL(string: "http://something.com/api")
guard let requestUrl = url else { fatalError() }
// Prepare URL Request Object
var request = URLRequest(url: requestUrl)
request.httpMethod = "POST"
Set Post parameter
let parameters: [String: String] = [
"user_ID": "1",
]
let jsonData = try JSONEncoder().encode(parameters)
request.httpBody = jsonData
Take request to our web api
// Perform HTTP Request
let task = URLSession.shared.dataTask(with: request) { (data: Data?, response: URLResponse?, error: Error?) in
// Check for Error
if let error = error {
print("Error took place \(error)")
return
}
guard let data = data else { return }
do {
let myEnterprise = try JSONDecoder().decode(Enterprise.self, from: data)
print("Response data:\n \(myEnterprise)")
print("Response data:\n \(myEnterprise.returnData)")
} catch let jsonErr {
print(jsonErr)
}
}
task.resume()
myEnterprise is always nil. Can anyone help me?
Related
I'm trying to improve my error handling when I don't get back any data in my JSON. The function below works fine without any issues except if I catch an error. I'm not sure of how to pass the error to prompt the user or is the way to handle the error if googlebusinessinfo is nil I likely have no data and pass a generic error?
Here's my function:
func getBusinessReviews(googleUrl: String, completion: #escaping (WelcomeReview?) -> ()) {
// Create URL
let url = URL(string: googleUrl)
guard let requestUrl = url else { fatalError() }
// Create URL Request
var request = URLRequest(url: requestUrl)
// Specify HTTP Method to use
request.httpMethod = "GET"
//Set HTTP Header
// Send HTTP Request
let task = URLSession.shared.dataTask(with: request) { (data, response, error) in
// Specify HTTP Method to use
request.httpMethod = "GET"
print("(Google)Do we have any data: \(String(describing: data))")
// Check if Error took place
if let error = error {
print("Error took place \(error)")
return
}
// Read HTTP Response Status code
if let response = response as? HTTPURLResponse {
print("(Google)Response HTTP Status code: \(response.statusCode)")
}
// Convert HTTP Response Data to a simple String
if let data = data, let dataString = String(data: data, encoding: .utf8) {
print("Googledata Response data string:\n \(dataString)")
}
if let googlebusinessdata = data {
do {
let googlebusinessinfo = try JSONDecoder().decode(WelcomeReview.self, from: googlebusinessdata)
print("googledata \(googlebusinessinfo)")
completion(googlebusinessinfo)
} catch
{
print("googledata error \(error.localizedDescription)")
let googebusinessinfoerror = error.localizedDescription
}
}
}
task.resume()
}
First of all you can improve the error handling immensely if you print error instead of error.localizedDescription in a Decoding catch block. The former shows the real error, the latter a meaningless generic message.
To answer your question use the generic Result type
func getBusinessReviews(googleUrl: String, completion: #escaping (Result<WelcomeReview,Error>) -> ()) {
// Create URL
let url = URL(string: googleUrl)
guard let requestUrl = url else { fatalError() }
// Create URL Request
var request = URLRequest(url: requestUrl)
// Specify HTTP Method to use
request.httpMethod = "GET"
//Set HTTP Header
// Send HTTP Request
let task = URLSession.shared.dataTask(with: request) { (data, response, error) in
// Specify HTTP Method to use
request.httpMethod = "GET"
print("(Google)Do we have any data: \(String(describing: data))")
// Check if Error took place
if let error = error {
print("Error took place \(error)")
completion(.failure(error))
return
}
// Read HTTP Response Status code
if let response = response as? HTTPURLResponse {
print("(Google)Response HTTP Status code: \(response.statusCode)")
}
// Convert HTTP Response Data to a simple String
if let data = data, let dataString = String(data: data, encoding: .utf8) {
print("Googledata Response data string:\n \(dataString)")
do {
let googlebusinessinfo = try JSONDecoder().decode(WelcomeReview.self, from: data)
print("googledata \(googlebusinessinfo)")
completion(.success(googlebusinessinfo))
} catch
{
print("googledata error:", error)
let googebusinessinfoerror = error.localizedDescription
completion(.failure(error))
}
}
}
task.resume()
}
and call it
getBusinessReviews(googleUrl: "Foo") { result in
switch result {
case .success(let info): print(info)
case .failure(let error): print(error)
}
}
So I'm trying to make an app in Swift for which I need to login to the OAuth to retrieve an access token. The API takes the parameters 'grant_type' and 'code'.
I've tried:
let params = ["grant_type":"authorization_code", "code":"123456789"] as Dictionary<String, String>
var request = URLRequest(url: URL(string: "https://myschool.zportal.nl/api/v3/oauth/token")!)
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
do {
let json = try JSONSerialization.jsonObject(with: data!) as! Dictionary<String, AnyObject>
print(json)
} catch {
print("error")
}
})
task.resume()
This returns:
["response": {
data = (
);
details = "class org.springframework.web.bind.MissingServletRequestParameterException: Required String parameter 'grant_type' is not present";
endRow = 0;
eventId = 216795;
message = "Internal problems.";
startRow = 0;
status = 500;
totalRows = 0;
}]
This is weird, because I did parse the 'grant_type' parameter, and as the correct value.
It should return something like:
{
"response": {
"status":200,
"message":"",
"startRow":0,
"endRow":27,
"totalRows":27,
"data":[
{
},
...
]
}
}
The standard message format requires a Form URL Encoded body, not a JSON one. Maybe adapt your code as in this Swift article.
Got it working:
#IBAction func sendButtonPressed(_ sender: UIButton) {
let urlString = "https://myschool.zportal.nl/api/v3/oauth/token"
performRequest(urlString: urlString)
}
func performRequest(urlString: String) {
if let url = URL(string: urlString) {
var request = URLRequest(url: url)
request.httpMethod = "POST"
request.httpBody = "grant_type=authorization_code&code=1234567890".data(using: .utf8)
let session = URLSession(configuration: .default)
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()
}
}
Not the nicest code but I'll polish it later.
At first I parsed JSON but it turned out I needed to parse a String and turn it into a Data type using: .data(using: .utf8)
I am very new to XCODE and iOS and I can't figure out how to do an authentication on IBM Domino server. I am trying to do a simple app to get some data from the server.
This is the latest version of my attempt. Bear in mind, that couldn't find information on what IBM Domino server needs. But I've done tons of authentications with javascript. I've deliberatly left the commented part, which is one of the attempts to do a login.
func doLogin(){
print("entered doLogin")
let myUrl: String = "https://url.com/names?login"
guard let url = URL(string: myUrl.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed)!)else {
print("Error: cannot create URL")
return
}
var request = URLRequest.init(url: url)
request.httpMethod = "POST"
let params = ["Username":String(describing: self.username), "Password":String(describing: self.password)]
request.httpBody = try? JSONSerialization.data(withJSONObject: params, options: [])
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
//URLSession.shared.dataTask(with: request) { (data:Data?, response:URLResponse?, error:Error?) in
// if let safeData = data{
// print("response: \(String(data:safeData, encoding:.utf8))")
// }
//}
//let postString = "Username=\(String(describing: self.username))&Password=\(String(describing: self.password))"
//request.httpBody = postString.data(using:String.Encoding.utf8)
request.timeoutInterval = 30.0
//print(request)
let configuration = URLSessionConfiguration.default
let session = URLSession(configuration : configuration)
//let session = URLSession(configuration: configuration, delegate: self as! URLSessionDelegate, delegateQueue: nil)
let task = session.dataTask(with: request) {
(data : Data?, response:URLResponse?, error) in
// check for any errors
guard error == nil else {
print("error calling POST on url")
print(error!)
return
}
// make sure we got data
guard let responseData = data else {
print("Error: did not receive data")
return
}
do {
print ("responseData:")
print(responseData)
}
}
//print ("response:")
//print(task.response)
task.resume()
I have tried Alamofire, I have tried it with all my heart. It just does not work for me. I finally got http GET working, but I need to get http POST working. Our POST API's take a Request object that has all the necessary data in it. I have requested the backend developers to provide me with a KEY-VALUE pair JSON (no embedded objects/arrays) so that I can use a Dictionary in my swift code convert that to json and send the request. All I need is now to convert the below code to POST.
My earlier questions that did not help much.
NSInvalidArgumentException Invalid type in JSON write DemographicsPojo
Swift 3.0, Alamofire 4.0 Extra argument 'method' in call
I have given up on Alamofire. I want to use Foundation classes. Simple basic and fundamental way of life :).
func callWebService(url : String) {
// Show MBProgressHUD Here
var config :URLSessionConfiguration!
var urlSession :URLSession!
config = URLSessionConfiguration.default
urlSession = URLSession(configuration: config)
// MARK:- HeaderField
let HTTPHeaderField_ContentType = "Content-Type"
// MARK:- ContentType
let ContentType_ApplicationJson = "application/json"
//MARK: HTTPMethod
let HTTPMethod_Get = "GET"
let callURL = URL.init(string: url)
var request = URLRequest.init(url: callURL!)
request.timeoutInterval = 60.0 // TimeoutInterval in Second
request.cachePolicy = URLRequest.CachePolicy.reloadIgnoringLocalCacheData
request.addValue(ContentType_ApplicationJson, forHTTPHeaderField: HTTPHeaderField_ContentType)
request.httpMethod = HTTPMethod_Get
let dataTask = urlSession.dataTask(with: request) { (data,response,error) in
if error != nil{
print("Error **")
return
}
do {
let resultJson = try JSONSerialization.jsonObject(with: data!, options: []) as? [String:AnyObject]
print("Result",resultJson!)
} catch {
print("Error -> \(error)")
}
}
dataTask.resume()
print("..In Background..")
}
Just pass JSON string and the API URL to this function. Complete code for POST.
func POST(api:String,jsonString:String,completionHandler:#escaping (_ success:Bool,_ response:String?,_ httpResponseStatusCode:Int?) -> Void) {
let url = URL(string: api)
var request: URLRequest = URLRequest(url: url!)
request.httpMethod = "POST"
request.setValue("application/json", forHTTPHeaderField:"Content-Type")
request.timeoutInterval = 60.0
//additional headers
if let token = Helper.readAccessToken() {
request.setValue("\(token)", forHTTPHeaderField: "Authorization")
}
let jsonData = jsonString.data(using: String.Encoding.utf8, allowLossyConversion: true)
request.httpBody = jsonData
let task = URLSession.shared.dataTask(with: request) {
(data: Data?, response: URLResponse?, error: Error?) -> Void in
var responseCode = 0
if let httpResponse = response as? HTTPURLResponse {
responseCode = httpResponse.statusCode
print("responseCode \(httpResponse.statusCode)")
}
if error != nil {
completionHandler(false, error?.localizedDescription,nil)
} else {
let responseString = String(data: data!, encoding: .utf8)
completionHandler(true, responseString, responseCode)
}
}
task.resume()
}
I've wrote a function for GET request from rest and it says that i have method not allowed - code 405 which is werid and i can not find solution for that.
I am doing GET via current token which was assigned to the user after logged in.
Could someone have a look on the code and tell me what might be wrong ?
func getRequest() -> Void {
let json: [String: Any] = ["token": SessionMenager.Instance.token]
let jsonData = try? JSONSerialization.data(withJSONObject: json)
// create post request
let url = URL(string: MY_URL)!
var request = URLRequest(url: url)
request.httpMethod = "GET"
// insert json data to the request
request.httpBody = jsonData
request.setValue("application/json;charest=utf-8", forHTTPHeaderField: "Content-Type")
let task = URLSession.shared.dataTask(with: request) { data, response, error in
guard let data = data, error == nil else {
print(error?.localizedDescription ?? "No data")
return
}
if let httpResponse = response as? HTTPURLResponse {
print("GET : code - \(httpResponse.statusCode)")
}
let responseJSON = try? JSONSerialization.jsonObject(with: data, options: [])
if let responseJSON = responseJSON as? [String: Any] {
print(responseJSON)
} else{
print(error.debugDescription)
}
}
task.resume()
}
Thanks in advance!!