Not able to send post request using URLRequest

Question

I am trying to send post request through URLSession

I am constructing my payload using this

let params: [String : Any] = [
                "name": username,
                "password": password,
                "email": email,
                "c_password": confirmPassword
            ]

also with this

var urlParser = URLComponents()
            urlParser.queryItems = [
                URLQueryItem(name: "name", value: username),
                URLQueryItem(name: "password", value: password),
                URLQueryItem(name: "email", value: email),
                URLQueryItem(name: "c_password", value: confirmPassword)
            ]

and this setting it to httpBody like this

 request.httpBody = parameters.data(using: .utf8)

and calling my function but it throws me the error

The request was well formed but was unable to be followed due to semantic errors

But when I try to send request in this way

let parameters = "name=test&password=Pass@123&c_password=Pass@123&[email protected]"

it works

but when I try to make it dynamic

let parameters = "name=\(username)&password=\(password)&c_password=\(confirmPassword)&email=\(email)"

it gives me error. I am not sure what I am doing wrong

Complete code

if let url = URL(string: Constants.REGISTRATION_URL){
            var request = URLRequest(url: url)
            request.httpMethod = "POST"
            let params: [String : Any] = [
                "name": username,
                "password": password,
                "email": email,
                "c_password": confirmPassword
            ]
            var urlParser = URLComponents()
            urlParser.queryItems = [
                URLQueryItem(name: "name", value: username),
                URLQueryItem(name: "password", value: password),
                URLQueryItem(name: "email", value: email),
                URLQueryItem(name: "c_password", value: confirmPassword)
            ]
          //  let httpBodyString = urlParser.percentEncodedQuery
           // let parameters = "name=test&password=Pass@123&c_password=Pass@123&[email protected]"
            let parameters  = "name=\(username)&password=\(password)&c_password=\(confirmPassword)&email=\(email)"
          
            request.addValue("Application/x-www-form-urlencoded", forHTTPHeaderField:"Content-Type")
             request.httpBody = parameters.data(using: .utf8)
            APIManager.sharedInstance.postCall(request: request, onSuccess: { json in
                DispatchQueue.main.async {
                    
                    
                }
            }, onFailure: { error in
                do{
                    let errorModel = try JSONDecoder().decode(ErrorModel.self, from: Data(error.utf8))
                    DispatchQueue.main.async {
                        self.showAlertMessage(alertMessage: errorModel.errors[0].detail)
                    }
                }catch{
                    DispatchQueue.main.async {
                        self.showAlertMessage(alertMessage: error.localizedDescription)
                    }
                }
            })
        }

Answer 1

The problem is that you're attempting to send a GET query string to a POST request.

GET requests expect a character escaped string (like what you have).

POST requests expect (mostly )a dictionary object (like your param dictionary)

See this answer for how to set a POST request properly