URLSession.datatask with request block not called in background

Question

URLSession data task block is not calling when the app is in background and it stuck at dataTask with request.
When I open the app the block gets called. By the way I'm using https request.
This is my code:

    let request = NSMutableURLRequest(url: URL(string: url as String)!,

                                      cachePolicy: .reloadIgnoringCacheData,

                                      timeoutInterval:20)

    request.httpMethod = method as String

    request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")

    let session = URLSession.shared

    let data = params.data(using: String.Encoding.utf8.rawValue)

    request.httpBody = data

    session.dataTask(with: request as URLRequest,completionHandler:

        {(data, response, error) -> Void in

         if error == nil

            {

                do {

                    let result = try JSONSerialization.jsonObject(with: data!, options:

                        JSONSerialization.ReadingOptions.mutableContainers)

                    print(result)

                     completionHandler(result as AnyObject?,nil)

                }

                catch let JSONError as NSError{

                    completionHandler(nil,JSONError.localizedDescription as NSString?)

                }

            }

            else{

                completionHandler(nil,error!.localizedDescription as NSString?)                    

            }                

    }).resume()

Working perfectly when the app is in active state. Is there anything wrong in my code. please point me

user_1953516 · Answer

Or simply start a BackgroundTask

func send(...) {
  let backgroundTaskID = UIApplication.shared.beginBackgroundTask(expirationHandler: nil)
  let session = URLSession(configuration: .default)

  // ... after all the main logic, when you finish:
  DispatchQueue.main.async {
    completion(result)
    UIApplication.shared.endBackgroundTask(backgroundTaskID)
  }
}

URLSession.datatask with request block not called in background

4 Answers