Receive POST request from Swift in Node.js - ios

Question

I am trying to receive and process a POST request being sent from my iOS app to my Node.js web server. The server responds with HTTP Error 502 whenever I try to send this POST request. Could you please look at my code below and see what is wrong with it? Thank you!
Node.js Code
app.post('/applogin', function(req, res) {
var parsedBody = JSON.parse(req.body);
console.log(parsedBody)
});
Swift Code (POST function)
func httpPost(jsonData: Data) {
if !jsonData.isEmpty {
var request = URLRequest(url: url)
request.httpMethod = "POST"
request.httpBody = jsonData
URLSession.shared.getAllTasks { (openTasks: [URLSessionTask]) in
NSLog("open tasks: \(openTasks)")
}
let task = URLSession.shared.dataTask(with: request, completionHandler: { (responseData: Data?, response: URLResponse?, error: Error?) in
NSLog("\(response)")
})
task.resume()
}
}
Swift Code (sending of the POST request)
#IBAction func onClick(_ sender: Any) {
let username = Username.text
let password = Password.text
var dataString = "username: \(username), password: \(password)"
let data = dataString.data(using: .utf8)
httpPost(jsonData: data!)
}
Thanks in advance!

Answer 1

You have to send a json instead dataString, and you have to set the "Content Type" header with value "application/json"
Swift 2
let request = NSMutableURLRequest(URL: requestUrl)
request.HTTPMethod = "POST"
let params = ["username" : username, "password" : password] as Dictionary<String, AnyObject>
request.HTTPBody = NSJSONSerialization.dataWithJSONObject(params, options:NSJSONWritingOptions.PrettyPrinted)
request.addValue("application/json", forHTTPHeaderField: "Content-Type")

Answer 2

Many answers they don't mention that we need to set header for the request from Swift side before sending to the backend otherwise it'll be a string in a wrong format that we can't use JSON.parse, here's what I firgured out (NOTE the IMPORTANT line):
let json = [
"email": emailTextField.text
]
let jsonData = try! JSONSerialization.data(withJSONObject: json)
let url = URL(string: BASE_URL + "/auth/register")!
var request = URLRequest(url: url)
request.httpMethod = "POST"
// insert json data to the request
request.httpBody = jsonData
//IMPORTANT
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
request.addValue("application/json", forHTTPHeaderField: "Accept")
let task = URLSession.shared.dataTask(with: request) { data, response, error in
guard let data = data, error == nil else {
print(error?.localizedDescription ?? "No data")
return
}
let responseJSON = try? JSONSerialization.jsonObject(with: data, options: [])
if let responseJSON = responseJSON as? [String: Any] {
print(responseJSON)
}
}
task.resume()
And in your NodeJS with Express just call req.body and you're done

Answer 3

Try this:
app.post('/applogin', function(req, res) {
var parsedBody = JSON.parse(req.body);
console.log(parsedBody)
res.send("Request received")
});