Swift-4 : How to fetch data using POST request with Parameters in URLSession with "Content-Type" : "application/x-www-form-urlencoded" - ios

Question

Friends, I've gone through lot's of examples, which are available on S.O. Though I haven't received proper answer, and still I'm facing issue in getting data via api request using URLSession with Post request & passing parameters with it.
First, I'ld like to show you, what I have. tried till now...
func requestApiCall(){
let renewal_id = ""
let policy_no = ""
let client_name = ""
let client_id = ""
let product_name = ""
let created_date_from = ""
let created_date_to = ""
let policy_expiry_from = ""
let policy_expiry_to = ""
self.parameters = ["renewal_id":renewal_id,"policy_no":policy_no,"client_name":client_name,"client_id":client_id,"product_name":product_name,"created_date_from":created_date_from,"created_date_to":created_date_to,"policy_expiry_from":policy_expiry_from,"policy_expiry_to":policy_expiry_to]
let config = URLSessionConfiguration.default
config.httpAdditionalHeaders = [
"Accept" : "application/json",
"Content-Type" : "application/x-www-form-urlencoded"
]
let session = URLSession(configuration: config)
let Url = String(format: "http://myapi-url");
let serviceUrl = URL(string: Url)
var request = URLRequest(url: serviceUrl!)
print(request.url!)
request.httpMethod = "POST"
request.timeoutInterval = 60
request.httpBody = try! JSONSerialization.data(withJSONObject: parameters!, options: [])
let task = session.dataTask(with: request as URLRequest, completionHandler: {data, response, error -> Void in
if error == nil{
print(response!)
}
else {
print(error?.localizedDescription as Any)
}
print(response!)
guard let httpResponse = response as? HTTPURLResponse, let receivedData = data
else {
print("error: not a valid http response")
return
}
switch (httpResponse.statusCode)
{
case 200: //The request was fulfilled
let response = NSString (data: receivedData, encoding: String.Encoding.utf8.rawValue)
if response == "SUCCESS"
{
print("Network - HandShaking Successfull...!!!")
}
else{
print("Network - HandShaking is not successfull...!!!")
}
case 400:
print("response-status - 400 : The request had bad syntax or was inherently impossible to be satisfied.")
case 500:
print("\nresponse-status - 500 : Internal Server Error...!!!")
default:
print("response-status - Unknown : Received Response => \(httpResponse.statusCode)")
}
})
task.resume()
}
After running above function, I'm getting httpResponse.statusCode = 500
But when I run this in postman, I get response properly, as aspected.
Postman Api-Request
Also I have tried to generate code-snippets through postman...which are as follow...
func postmanSnippetApiCall(){
let headers = [
"Content-Type": "application/x-www-form-urlencoded",
"cache-control": "no-cache",
"Postman-Token": "5d571157-86c5-4eac-ba6d-b00779ae5dbd"
]
let postData = NSMutableData(data: "renewal_id=".data(using: String.Encoding.utf8)!)
postData.append("&policy_no=".data(using: String.Encoding.utf8)!)
postData.append("&client_name=".data(using: String.Encoding.utf8)!)
postData.append("&client_id=".data(using: String.Encoding.utf8)!)
postData.append("&product_name=".data(using: String.Encoding.utf8)!)
postData.append("&created_date_from=".data(using: String.Encoding.utf8)!)
postData.append("&created_date_to=".data(using: String.Encoding.utf8)!)
postData.append("&policy_expiry_from=".data(using: String.Encoding.utf8)!)
postData.append("&policy_expiry_to=".data(using: String.Encoding.utf8)!)
postData.append("&undefined=undefined".data(using: String.Encoding.utf8)!)
let request = NSMutableURLRequest(url: NSURL(string: "http://myapiurl")! as URL,
cachePolicy: .useProtocolCachePolicy,
timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers
request.httpBody = postData as Data
let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
if (error != nil) {
print(error)
} else {
let httpResponse = response as? HTTPURLResponse
print(httpResponse)
}
})
dataTask.resume()
}
But in postman generated code snippet, I'm receiving error on this line i.e request.httpBody = postData as Data and error is this one : Cannot convert value of type 'NSMutableData' to type 'Data' in coercion
If I use thirdParty Library i.e Alamofire, then I'm able to get data very easily.
Alamofire code snippet...runs perfectly..& gives proper response.
func apiRequestByAlamofire(){
let urlString = "http://myapiurl"
let params: [String: Any]? = ["renewal_id":"","policy_no":"","client_name":"","client_id":"","product_name":"","created_date_from":"","created_date_to":"","policy_expiry_from":"","policy_expiry_to":""]
Alamofire.request(urlString, method: .post, parameters: params).responseJSON { response in
print(response) //Here getting perfect response successfully...!!!
}
}
But still I'm struggling this via URLSession...!!!
And still I doubt, that why I'm getting too much problems, while doing with URLSession.
Friends for above my doubt, please I'm open to your suggestions, as well as please help me out to understand it.
Don't know, where am I going wrong. please help me out here.

Answer 1

After searching and fighting a lot with this I have come up with this solution:
guard var components = URLComponents(url: URL(string: "http://example.com")!, resolvingAgainstBaseURL: true)
else { fatalError("Couldn't create URLComponents") }
components.queryItems = params.map { k, v in URLQueryItem(name: k, value: v) }
var request = URLRequest(url: baseUrl.appendingPathComponent(path.rawValue))
request.httpBody = Data(components.query!.utf8)
request.httpMethod = "POST"
The "example.com" can literally be that, because I'm just using URLComponents to encode the parameters.

Answer 2

I am giving you simple function, You can edit this function as per your requirement. You can change your URL and params as well. And in the response, I have written two-line if you are taking JSON array from the server then use the first one if you are taking object then second one else remove Both lines.
func abc() {
let request = NSMutableURLRequest(url: URL(string: "Your URL")!)
request.httpMethod = "POST"
let postString = "param_name_one=\( value_1 )&param_name_two=\(value_2)&........."
request.httpBody = postString.data(using: String.Encoding.utf8)
let task = URLSession.shared.dataTask(with: request as URLRequest) {
data, response, error in
if(error != nil){
// Show Error Message
} else{
do {
//For JSON ARRAY
let jsonItem = try JSONSerialization.jsonObject(with: data!, options: .allowFragments) as! NSArray
let json = jsonItem[0] as AnyObject
//For JSON object
let json_object = try JSONSerialization.jsonObject(with: data!, options: .allowFragments) as AnyObject
print(json_object)
} catch {
}
}
}
task.resume();
}