REST API's issue - ios

Question

I am working on REST API's in iOS application.
I have tested Server URL and Parameters of POST method.
It is returning with
Your browser sent a request that this server could not understand
this error in response.
For the GET request API is working fine.
If anyone faced the same issue please let me know.
Thank you.
Please check my web service model
let configuration = URLSessionConfiguration.default;
let session = URLSession(configuration: configuration, delegate: nil, delegateQueue: nil)
var urlString = String()
urlString.append(Constant.BASE_URL)
urlString.append(methodName)
let encodedUrl = urlString.addingPercentEncoding(withAllowedCharacters: CharacterSet.urlQueryAllowed)
let serverUrl: URL = URL(string: (encodedUrl?.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed))!)!
var request : URLRequest = URLRequest(url: serverUrl, cachePolicy: .useProtocolCachePolicy, timeoutInterval: 60.0)
var paramStr : String = String()
if requestDict.count > 0 {
let keysArray = requestDict.keys
for key in keysArray {
if paramStr.isEmpty{
paramStr.append("\(key)=\(requestDict[key]! as! String)")
}else{
paramStr.append("&\(key)=\(requestDict[key]! as! String)")
}
}
}
let postData:Data = try! JSONSerialization.data(withJSONObject: requestDict)//paramStr.data(using: .utf8)!
let reqJSONStr = String(data: postData, encoding: .utf8)
let postLength = "\(postData.count)"
request.httpMethod = "POST"
request.setValue(postLength, forHTTPHeaderField: "Content-Length")
//request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
//request.httpBody = reqJSONStr?.data(using: .utf8)
request.setValue("application/json", forHTTPHeaderField: "Content-Type")
request.httpBody = try! JSONSerialization.data(withJSONObject: requestDict)
if headerValue != nil{
let allkeys = headerValue.keys
for key in allkeys {
request.setValue(headerValue[key] as! String?, forHTTPHeaderField: key)
}
}
let postDataTask : URLSessionDataTask = session.dataTask(with: request, completionHandler:
{
data, response, error in
if data != nil && error == nil{
let res = String(data: data!, encoding: .utf8)
let dict = convertToDictionary(text: res!)
if let httpResponse = response as? HTTPURLResponse {
//print("error \(httpResponse.statusCode)")
if httpResponse.statusCode == 200
{
DispatchQueue.main.async {
successBlock (response!,(dict)!)
}
}
else
{
if (error?.localizedDescription) != nil
{
errorBlock((error?.localizedDescription)! as String)
}
else
{
errorBlock("")
}
}
}
else
{
errorBlock((error?.localizedDescription)! as String)
}
}
else{
if let httpResponse = error as? HTTPURLResponse {
//print("error \(httpResponse.statusCode)")
}
errorBlock((error?.localizedDescription)! as String)
}
})
postDataTask.resume()

Answer 1

Assuming that your backend is expecting an form-urlencoded request, then you should convert your parameters dictionary in an string url encoded
This is an example
let parameters : [String:Any] = ["ajax":1,"test":"abuela"]
var queryItems : [URLQueryItem] = []
for key in parameters.keys {
if let value = parameters[key] as? String {
queryItems.append(URLQueryItem(name: key, value: value))
}else{
queryItems.append(URLQueryItem(name: key, value: String(describing:parameters[key]!)))
}
}
var urlComponents = URLComponents()
urlComponents.queryItems = queryItems
then if you
print(urlComponents.percentEncodedQuery!)
you will get
test=abuela&ajax=1
then with this you need to add in your urlString
urlString.append("&" + urlComponents.percentEncodedQuery!)
FULL CODE
let configuration = URLSessionConfiguration.default;
let session = URLSession(configuration: configuration, delegate: nil, delegateQueue: nil)
var urlString = String()
urlString.append(Constant.BASE_URL)
urlString.append(methodName)
var queryItems : [URLQueryItem] = []
for key in parameters.keys {
if let value = parameters[key] as? String {
queryItems.append(URLQueryItem(name: key, value: value))
}else{
queryItems.append(URLQueryItem(name: key, value: String(describing:parameters[key]!)))
}
}
var urlComponents = URLComponents()
urlComponents.queryItems = queryItems
print(urlComponents.percentEncodedQuery!)
urlString.append("&" + urlComponents.percentEncodedQuery!)
let encodedUrl = urlString.addingPercentEncoding(withAllowedCharacters: CharacterSet.urlQueryAllowed)
let serverUrl: URL = URL(string: urlString)!
var request : URLRequest = URLRequest(url: serverUrl, cachePolicy: .useProtocolCachePolicy, timeoutInterval: 60.0)
request.httpMethod = "POST"
request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
let postDataTask : URLSessionDataTask = session.dataTask(with: request, completionHandler:
{
data, response, error in
if data != nil && error == nil{
let res = String(data: data!, encoding: .utf8)
let dict = convertToDictionary(text: res!)
if let httpResponse = response as? HTTPURLResponse {
//print("error \(httpResponse.statusCode)")
if httpResponse.statusCode == 200
{
DispatchQueue.main.async {
successBlock (response!,(dict)!)
}
}
else
{
if (error?.localizedDescription) != nil
{
errorBlock((error?.localizedDescription)! as String)
}
else
{
errorBlock("")
}
}
}
else
{
errorBlock((error?.localizedDescription)! as String)
}
}
else{
if let httpResponse = error as? HTTPURLResponse {
//print("error \(httpResponse.statusCode)")
}
errorBlock((error?.localizedDescription)! as String)
}
})
postDataTask.resume()
IF your backend is waiting application/json http body encoded
You are passing an JSON object in the httpBody but your contentType header is wrong instead of "application/x-www-form-urlencoded" should be "application/json", I think your json convertion is wrong try using your requestDict directly and JSONSerialization will convert the dictionary in a valid JSON object that you can use in your request.httpBody
replace
request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
by
request.setValue("application/json", forHTTPHeaderField: "Content-Type")
Use this to convert to JSON your requestDict parameters dictionary
request.httpBody = try! JSONSerialization.data(withJSONObject: requestDict)