Preventing URLSession redirect in Swift

Question

I need to fetch a redirecting URL but prevent redirection in Swift. From other posts and Apple docs I understand I must implement the delegate method URLS

Answer 1

I also found the solution helpful, but I am using Swift 4.2 in my current project.

So, here is an adapted shorter version of the solution above, that also works with Swift 4.2 and Xcode 10.

import Foundation
import PlaygroundSupport

PlaygroundPage.current.needsIndefiniteExecution = true

class MySession: NSObject, URLSessionTaskDelegate {

    func urlSession(_ session: URLSession, task: URLSessionTask, willPerformHTTPRedirection response: HTTPURLResponse, newRequest request: URLRequest, completionHandler: @escaping (URLRequest?) -> Void) {
        completionHandler(nil)
    }
}

func getDataFromServerWithSuccess(myURL: String, noRedirect: Bool) {
    let myDelegate: MySession? = noRedirect ? MySession() : nil

    let session = URLSession(configuration: URLSessionConfiguration.default, delegate: myDelegate, delegateQueue: nil)
    let loadDataTask = session.dataTask(with: URL(string:myURL)!) { (data, response, error) in

        // OMITTING ERROR CHECKING FOR BREVITY
        if let data = data {
            if let dataString = String(bytes: data, encoding: .utf8) {
                print(dataString)
                if dataString.contains("Bitly") == true {
                    print("success: redirection was prevented")
                } else {
                    print("failure: redirection went through")
                }
            }
        }
    }
    loadDataTask.resume()
}

getDataFromServerWithSuccess(myURL: "http://bitly.com/filmenczer", noRedirect: true)