// Hi, i got response from url but getting error as below in title, please fix the issue.
Error Domain=NSCocoaErrorDomain Code=3840 "Invalid value around character 0." UserInfo={NSDebugDescription=Invalid value around character 0
let Url = String(format: "http://www.fgndbdsn.in/index.php?route=api/mywebservices/addition")
guard let serviceUrl = URL(string: Url) else { return }
let parameterDictionary = ["first" : "25", "second" : "25"]
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 {
print(data)
do {
let json = try JSONSerialization.jsonObject(with: data, options: .allowFragments) as! [[String:Any]]
print(json)
}catch {
print(error)
}
}
}.resume()
The response from the server must be valid JSON with a top level container which is an array or dictionary.
I am trying to reach a site that should take the username and password given and return a JSON which contains information stating whether or not the login data provided was valid or not.
However, all I'm getting back is the site's HTML code instead of a response. I've tried the request with the same parameters on https://www.hurl.it/ and have gotten the correct response so that does not seem to be the issue.
I use the following code:
private func uploadToAPI(username: String, password: String) {
guard let url = URL(string: "http://api.foo.com/login.php"),
let encodedUsername = username.addingPercentEncoding(withAllowedCharacters: CharacterSet.alphanumerics),
let encodedPassword = password.addingPercentEncoding(withAllowedCharacters: CharacterSet.alphanumerics) else {
self.loginButton.isLoading = false
return
}
let httpBodyParameters = ["user": encodedUsername, "password": encodedPassword, "client": "ios", "version": "5"]
var request = URLRequest(url: url)
request.httpMethod = "POST"
request.httpBody = try? JSONSerialization.data(withJSONObject: httpBodyParameters, options: JSONSerialization.WritingOptions.prettyPrinted)
request.setValue("application/json", forHTTPHeaderField: "Content-Type")
request.setValue("application/json", forHTTPHeaderField: "Accept")
URLSession.shared.dataTask(with: request) { (data, response, error) in
if let response = response {
print(response.mimeType) // Prints "text/html"
}
if let data = data {
print(try? JSONSerialization.jsonObject(with: data, options: JSONSerialization.ReadingOptions.allowFragments)) // Prints nil
print(String(data: data, encoding: String.Encoding.utf8)) // Prints the site's HTML
}
}.resume()
}
I fail to see where the issue is. I've also tried not setting the HTTP headers but that makes no difference. Anyone got any ideas?
It seems like not setting the HTTP header fields and using a string literal instead of a Dictionary as HTTP body data did it for me.
For anyone interested this is the code that now receives the expected response:
guard let url = URL(string: "http://api.foo.com/login.php?"),
let encodedUsername = username.addingPercentEncoding(withAllowedCharacters: CharacterSet.alphanumerics),
let encodedPassword = password.addingPercentEncoding(withAllowedCharacters: CharacterSet.alphanumerics) else {
if let delegate = self.delegate {
delegate.viewModelDidRejectLogin(self)
}
return
}
let httpBodyString = "user=\(encodedUsername)&password=\(encodedPassword)&client=ios&version=5"
var request = URLRequest(url: url)
request.httpMethod = "POST"
request.httpBody = httpBodyString.data(using: String.Encoding.utf8)
URLSession.shared.dataTask(with: request) { (data, response, error) in
guard let data = data, error == nil else {
print(error)
return
}
do {
if let json = try JSONSerialization.jsonObject(with: data) as? [String : AnyObject] {
self.readLoginResponse(json)
}
} catch {
print(error)
}
}.resume()
I'm trying to POST a key parameter and a JSON dictionary body to an API but for some reason it won't work.
Here's my work so far.
#IBAction func POST(_ sender: Any) {
let url = URL(string: "http://apilink.com/updateProfile&=param")!
let jsonObject = ["FName":"Tarik",
"LName":"Salama"]
let jsonData = try! JSONSerialization.data(withJSONObject: jsonObject, options: [])
var request = URLRequest(url: url)
request.httpMethod = "post"
request.setValue("application/json", forHTTPHeaderField: "Content-Type")
request.addValue("application/json", forHTTPHeaderField: "Accept")
request.httpBody = jsonData
let task = URLSession.shared.dataTask(with: request) { (data, response, error) in
if let error = error {
print("error:", error)
return
}
do {
guard let data = data else { return }
guard let json = try JSONSerialization.jsonObject(with: data, options: []) as? [String: AnyObject] else { return }
print("json:", json)
} catch {
print("error:", error)
}
}
task.resume()
}
I get this error when I click the POST button:
error: Error Domain=NSCocoaErrorDomain Code=3840 "JSON text did not start with array or object and option to allow fragments not set." UserInfo={NSDebugDescription=JSON text did not start with array or object and option to allow fragments not set.}
What am I doing wrong?
I tried changing some stuff around after I checked some other threads like putting the parameter and the data dictionary into a key:value dictionary but the API responded and said that the data is invalid which means the whole thing was sent in an incorrect format.
Note: I'm not allowed to use 3rd party libraries like Alamofire and the API link is working fine as shown in the screenshot.
you can check the problem by printing the response data
do {
guard let data = data else { return }
print(String(data: data, encoding: .utf8) ?? "No Conversion") //Print Here
guard let json = try JSONSerialization.jsonObject(with: data, options: []) as? [String: AnyObject] else { return }
print("json:", json)
} catch {
print("error:", error)
}
look at the 'Print Here' line. I believe the response is not a valid json so when you try to parse the data to JSOn it always ends up in catch block.
In my app i'm trying to make http post request with json data. The following json must be transferred to api
{
"Password":"123456",
"Email":"test#gmail.com"
}
Here is my code for this task
let dict = ["Email": "test#gmail.com", "Password":"123456"] as [String: Any]
if let jsonData = try? JSONSerialization.data(withJSONObject: dict, options: []) {
let url = NSURL(string: "http://xxxxxxxxx.net/api/Login")!
let request = NSMutableURLRequest(url: url as URL)
request.httpMethod = "POST"
request.httpBody = jsonData
let task = URLSession.shared.dataTask(with: request as URLRequest){ data,response,error in
if error != nil{
print(error?.localizedDescription)
return
}
do {
let json = try JSONSerialization.jsonObject(with: data!, options: .mutableContainers) as? NSDictionary
if let parseJSON = json {
let resultValue:String = parseJSON["success"] as! String;
print("result: \(resultValue)")
print(parseJSON)
}
} catch let error as NSError {
print(error)
}
}
task.resume()
}
I'm getting the following error
Error Domain=NSCocoaErrorDomain Code=3840 "No value." UserInfo={NSDebugDescription=No value.}
The response data is empty. What I'm doing wrong, or i have missed something in my code?
Try two things:
First :
jsonData = try? JSONSerialization.data(withJSONObject: dict, options: .prettyPrinted)
then add logs if your data is converted into JSON. Convert your data into String and print the value.
Also add
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
before httpBody. Sometimes we have to tell server in our request that we are posting JSON data.
Hope this will help you!!
Happy Coding!
I'm trying to run a HTTP Request in Swift, to POST 2 parameters to a URL.
Example:
Link: www.thisismylink.com/postName.php
Params:
id = 13
name = Jack
What is the simplest way to do that?
I don't even want to read the response. I just want to send that to perform changes on my database through a PHP file.
The key is that you want to:
set the httpMethod to POST;
optionally, set the Content-Type header, to specify how the request body was encoded, in case server might accept different types of requests;
optionally, set the Accept header, to request how the response body should be encoded, in case the server might generate different types of responses; and
set the httpBody to be properly encoded for the specific Content-Type; e.g. if application/x-www-form-urlencoded request, we need to percent-encode the body of the request.
E.g., in Swift 3 and later you can:
let url = URL(string: "https://httpbin.org/post")!
var request = URLRequest(url: url)
request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
request.setValue("application/json", forHTTPHeaderField: "Accept")
request.httpMethod = "POST"
let parameters: [String: Any] = [
"id": 13,
"name": "Jack & Jill"
]
request.httpBody = parameters.percentEncoded()
let task = URLSession.shared.dataTask(with: request) { data, response, error in
guard
let data = data,
let response = response as? HTTPURLResponse,
error == nil
else { // check for fundamental networking error
print("error", error ?? URLError(.badServerResponse))
return
}
guard (200 ... 299) ~= response.statusCode else { // check for http errors
print("statusCode should be 2xx, but is \(response.statusCode)")
print("response = \(response)")
return
}
// do whatever you want with the `data`, e.g.:
do {
let responseObject = try JSONDecoder().decode(ResponseObject<Foo>.self, from: data)
print(responseObject)
} catch {
print(error) // parsing error
if let responseString = String(data: data, encoding: .utf8) {
print("responseString = \(responseString)")
} else {
print("unable to parse response as string")
}
}
}
task.resume()
Where the following extensions facilitate the percent-encoding request body, converting a Swift Dictionary to a application/x-www-form-urlencoded formatted Data:
extension Dictionary {
func percentEncoded() -> Data? {
map { key, value in
let escapedKey = "\(key)".addingPercentEncoding(withAllowedCharacters: .urlQueryValueAllowed) ?? ""
let escapedValue = "\(value)".addingPercentEncoding(withAllowedCharacters: .urlQueryValueAllowed) ?? ""
return escapedKey + "=" + escapedValue
}
.joined(separator: "&")
.data(using: .utf8)
}
}
extension CharacterSet {
static let urlQueryValueAllowed: CharacterSet = {
let generalDelimitersToEncode = ":#[]#" // does not include "?" or "/" due to RFC 3986 - Section 3.4
let subDelimitersToEncode = "!$&'()*+,;="
var allowed: CharacterSet = .urlQueryAllowed
allowed.remove(charactersIn: "\(generalDelimitersToEncode)\(subDelimitersToEncode)")
return allowed
}()
}
And the following Decodable model objects facilitate the parsing of the application/json response using JSONDecoder:
// sample Decodable objects for https://httpbin.org
struct ResponseObject<T: Decodable>: Decodable {
let form: T // often the top level key is `data`, but in the case of https://httpbin.org, it echos the submission under the key `form`
}
struct Foo: Decodable {
let id: String
let name: String
}
This checks for both fundamental networking errors as well as high-level HTTP errors. This also properly percent escapes the parameters of the query.
Note, I used a name of Jack & Jill, to illustrate the proper x-www-form-urlencoded result of name=Jack%20%26%20Jill, which is “percent encoded” (i.e. the space is replaced with %20 and the & in the value is replaced with %26).
See previous revision of this answer for Swift 2 rendition.
Swift 4 and above
func postRequest() {
// declare the parameter as a dictionary that contains string as key and value combination. considering inputs are valid
let parameters: [String: Any] = ["id": 13, "name": "jack"]
// create the url with URL
let url = URL(string: "www.thisismylink.com/postName.php")! // change server url accordingly
// create the session object
let session = URLSession.shared
// now create the URLRequest object using the url object
var request = URLRequest(url: url)
request.httpMethod = "POST" //set http method as POST
// add headers for the request
request.addValue("application/json", forHTTPHeaderField: "Content-Type") // change as per server requirements
request.addValue("application/json", forHTTPHeaderField: "Accept")
do {
// convert parameters to Data and assign dictionary to httpBody of request
request.httpBody = try JSONSerialization.data(withJSONObject: parameters, options: .prettyPrinted)
} catch let error {
print(error.localizedDescription)
return
}
// create dataTask using the session object to send data to the server
let task = session.dataTask(with: request) { data, response, error in
if let error = error {
print("Post Request Error: \(error.localizedDescription)")
return
}
// ensure there is valid response code returned from this HTTP response
guard let httpResponse = response as? HTTPURLResponse,
(200...299).contains(httpResponse.statusCode)
else {
print("Invalid Response received from the server")
return
}
// ensure there is data returned
guard let responseData = data else {
print("nil Data received from the server")
return
}
do {
// create json object from data or use JSONDecoder to convert to Model stuct
if let jsonResponse = try JSONSerialization.jsonObject(with: responseData, options: .mutableContainers) as? [String: Any] {
print(jsonResponse)
// handle json response
} else {
print("data maybe corrupted or in wrong format")
throw URLError(.badServerResponse)
}
} catch let error {
print(error.localizedDescription)
}
}
// perform the task
task.resume()
}
For anyone looking for a clean way to encode a POST request in Swift 5.
You don’t need to deal with manually adding percent encoding.
Use URLComponents to create a GET request URL. Then use query property of that URL to get properly percent escaped query string.
let url = URL(string: "https://example.com")!
var components = URLComponents(url: url, resolvingAgainstBaseURL: false)!
components.queryItems = [
URLQueryItem(name: "key1", value: "NeedToEscape=And&"),
URLQueryItem(name: "key2", value: "vålüé")
]
let query = components.url!.query
The query will be a properly escaped string:
key1=NeedToEscape%3DAnd%26&key2=v%C3%A5l%C3%BC%C3%A9
Now you can create a request and use the query as HTTPBody:
var request = URLRequest(url: url)
request.httpMethod = "POST"
request.httpBody = Data(query.utf8)
Now you can send the request.
Heres the method I used in my logging library: https://github.com/goktugyil/QorumLogs
This method fills html forms inside Google Forms.
var url = NSURL(string: urlstring)
var request = NSMutableURLRequest(URL: url!)
request.HTTPMethod = "POST"
request.setValue("application/x-www-form-urlencoded; charset=utf-8", forHTTPHeaderField: "Content-Type")
request.HTTPBody = postData.dataUsingEncoding(NSUTF8StringEncoding)
var connection = NSURLConnection(request: request, delegate: nil, startImmediately: true)
let session = URLSession.shared
let url = "http://...."
let request = NSMutableURLRequest(url: NSURL(string: url)! as URL)
request.httpMethod = "POST"
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
var params :[String: Any]?
params = ["Some_ID" : "111", "REQUEST" : "SOME_API_NAME"]
do{
request.httpBody = try JSONSerialization.data(withJSONObject: params, options: JSONSerialization.WritingOptions())
let task = session.dataTask(with: request as URLRequest as URLRequest, completionHandler: {(data, response, error) in
if let response = response {
let nsHTTPResponse = response as! HTTPURLResponse
let statusCode = nsHTTPResponse.statusCode
print ("status code = \(statusCode)")
}
if let error = error {
print ("\(error)")
}
if let data = data {
do{
let jsonResponse = try JSONSerialization.jsonObject(with: data, options: JSONSerialization.ReadingOptions())
print ("data = \(jsonResponse)")
}catch _ {
print ("OOps not good JSON formatted response")
}
}
})
task.resume()
}catch _ {
print ("Oops something happened buddy")
}
All the answers here use JSON objects. This gave us problems with the
$this->input->post()
methods of our Codeigniter controllers. The CI_Controller cannot read JSON directly.
We used this method to do it WITHOUT JSON
func postRequest() {
// Create url object
guard let url = URL(string: yourURL) else {return}
// Create the session object
let session = URLSession.shared
// Create the URLRequest object using the url object
var request = URLRequest(url: url)
// Set the request method. Important Do not set any other headers, like Content-Type
request.httpMethod = "POST" //set http method as POST
// Set parameters here. Replace with your own.
let postData = "param1_id=param1_value¶m2_id=param2_value".data(using: .utf8)
request.httpBody = postData
// Create a task using the session object, to run and return completion handler
let webTask = session.dataTask(with: request, completionHandler: {data, response, error in
guard error == nil else {
print(error?.localizedDescription ?? "Response Error")
return
}
guard let serverData = data else {
print("server data error")
return
}
do {
if let requestJson = try JSONSerialization.jsonObject(with: serverData, options: .mutableContainers) as? [String: Any]{
print("Response: \(requestJson)")
}
} catch let responseError {
print("Serialisation in error in creating response body: \(responseError.localizedDescription)")
let message = String(bytes: serverData, encoding: .ascii)
print(message as Any)
}
// Run the task
webTask.resume()
}
Now your CI_Controller will be able to get param1 and param2 using $this->input->post('param1') and $this->input->post('param2')
#IBAction func btn_LogIn(sender: AnyObject) {
let request = NSMutableURLRequest(URL: NSURL(string: "http://demo.hackerkernel.com/ios_api/login.php")!)
request.HTTPMethod = "POST"
let postString = "email: test#test.com & password: testtest"
request.HTTPBody = postString.dataUsingEncoding(NSUTF8StringEncoding)
let task = NSURLSession.sharedSession().dataTaskWithRequest(request){data, response, error in
guard error == nil && data != nil else{
print("error")
return
}
if let httpStatus = response as? NSHTTPURLResponse where httpStatus.statusCode != 200{
print("statusCode should be 200, but is \(httpStatus.statusCode)")
print("response = \(response)")
}
let responseString = String(data: data!, encoding: NSUTF8StringEncoding)
print("responseString = \(responseString)")
}
task.resume()
}